</table>
    </div>
    <div id="mainSection">
    <div id="mainBody">
    <h1 class="heading">Version History</h1>
    <p><b>1.0.100.0 - February XX, 2016 <font color="red">(release scheduled)</font></b></p>
    <ul>
      <li>Updated to <a href="https://www.sqlite.org/releaselog/3_10_2.html">SQLite 3.10.2</a>.</li>
      <li>Properly handle NULL values in the &quot;name&quot; column of the results returned by PRAGMA index_info(). Fix for <a href="https://system.data.sqlite.org/index.html/info/5251bd0878">[5251bd0878]</a>.</li>
      <li>For column types that resolve to boolean, recognize case-insensitive prefixes of &quot;True&quot; and &quot;False&quot;. Fix for <a href="https://system.data.sqlite.org/index.html/info/dbd65441a5">[dbd65441a5]</a>.</li>
      <li>Add NoVerifyTextAffinity connection flag to skip type affinity checking when fetching a column value as a string. Pursuant to <a href="https://system.data.sqlite.org/index.html/info/dbd65441a5">[dbd65441a5]</a>.</li>
    </ul>
    <p><b>1.0.99.0 - December 9, 2015</b></p>
    <ul>
      <li>Updated to <a href="https://www.sqlite.org/releaselog/3_9_2.html">SQLite 3.9.2</a>.</li>

      </table>
    </div>
    <div id="mainSection">
    <div id="mainBody">
    <h1 class="heading">Version History</h1>
    <p><b>1.0.100.0 - February XX, 2016 <font color="red">(release scheduled)</font></b></p>
    <ul>
      <li>Updated to <a href="https://www.sqlite.org/releaselog/3_11_0.html">SQLite 3.11</a>.</li>
      <li>Properly handle NULL values in the &quot;name&quot; column of the results returned by PRAGMA index_info(). Fix for <a href="https://system.data.sqlite.org/index.html/info/5251bd0878">[5251bd0878]</a>.</li>
      <li>For column types that resolve to boolean, recognize case-insensitive prefixes of &quot;True&quot; and &quot;False&quot;. Fix for <a href="https://system.data.sqlite.org/index.html/info/dbd65441a5">[dbd65441a5]</a>.</li>
      <li>Add NoVerifyTextAffinity connection flag to skip type affinity checking when fetching a column value as a string. Pursuant to <a href="https://system.data.sqlite.org/index.html/info/dbd65441a5">[dbd65441a5]</a>.</li>
    </ul>
    <p><b>1.0.99.0 - December 9, 2015</b></p>
    <ul>
      <li>Updated to <a href="https://www.sqlite.org/releaselog/3_9_2.html">SQLite 3.9.2</a>.</li>

 *
 * Written by Joe Mistachkin.
 * Released to the public domain, use at your own risk!
 *
-->
<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
  <PropertyGroup Label="UserMacros">
    <SQLITE_MANIFEST_VERSION>3.10.2.0</SQLITE_MANIFEST_VERSION>
    <SQLITE_RC_VERSION>3,10,2,0</SQLITE_RC_VERSION>
    <SQLITE_COMMON_DEFINES>_CRT_SECURE_NO_DEPRECATE;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;SQLITE_THREADSAFE=1;SQLITE_USE_URI=1;SQLITE_ENABLE_COLUMN_METADATA=1;SQLITE_ENABLE_STAT4=1;SQLITE_ENABLE_FTS3=1;SQLITE_ENABLE_LOAD_EXTENSION=1;SQLITE_ENABLE_RTREE=1;SQLITE_SOUNDEX=1;SQLITE_ENABLE_MEMORY_MANAGEMENT=1;SQLITE_ENABLE_API_ARMOR=1</SQLITE_COMMON_DEFINES>
    <SQLITE_EXTRA_DEFINES>SQLITE_PLACEHOLDER=1;SQLITE_HAS_CODEC=1</SQLITE_EXTRA_DEFINES>
    <SQLITE_WINCE_200X_DEFINES>SQLITE_OMIT_WAL=1</SQLITE_WINCE_200X_DEFINES>
    <SQLITE_WINCE_2013_DEFINES>HAVE_ERRNO_H=1;SQLITE_MSVC_LOCALTIME_API=1</SQLITE_WINCE_2013_DEFINES>
    <SQLITE_DEBUG_DEFINES>SQLITE_DEBUG=1;SQLITE_MEMDEBUG=1;SQLITE_ENABLE_EXPENSIVE_ASSERT=1</SQLITE_DEBUG_DEFINES>
    <SQLITE_RELEASE_DEFINES>SQLITE_WIN32_MALLOC=1</SQLITE_RELEASE_DEFINES>
    <SQLITE_DISABLE_WARNINGS>4055;4100;4127;4146;4210;4232;4244;4245;4267;4306;4389;4701;4703;4706</SQLITE_DISABLE_WARNINGS>

 *
 * Written by Joe Mistachkin.
 * Released to the public domain, use at your own risk!
 *
-->
<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
  <PropertyGroup Label="UserMacros">
    <SQLITE_MANIFEST_VERSION>3.11.0.0</SQLITE_MANIFEST_VERSION>
    <SQLITE_RC_VERSION>3,11,0,0</SQLITE_RC_VERSION>
    <SQLITE_COMMON_DEFINES>_CRT_SECURE_NO_DEPRECATE;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;SQLITE_THREADSAFE=1;SQLITE_USE_URI=1;SQLITE_ENABLE_COLUMN_METADATA=1;SQLITE_ENABLE_STAT4=1;SQLITE_ENABLE_FTS3=1;SQLITE_ENABLE_LOAD_EXTENSION=1;SQLITE_ENABLE_RTREE=1;SQLITE_SOUNDEX=1;SQLITE_ENABLE_MEMORY_MANAGEMENT=1;SQLITE_ENABLE_API_ARMOR=1</SQLITE_COMMON_DEFINES>
    <SQLITE_EXTRA_DEFINES>SQLITE_PLACEHOLDER=1;SQLITE_HAS_CODEC=1</SQLITE_EXTRA_DEFINES>
    <SQLITE_WINCE_200X_DEFINES>SQLITE_OMIT_WAL=1</SQLITE_WINCE_200X_DEFINES>
    <SQLITE_WINCE_2013_DEFINES>HAVE_ERRNO_H=1;SQLITE_MSVC_LOCALTIME_API=1</SQLITE_WINCE_2013_DEFINES>
    <SQLITE_DEBUG_DEFINES>SQLITE_DEBUG=1;SQLITE_MEMDEBUG=1;SQLITE_ENABLE_EXPENSIVE_ASSERT=1</SQLITE_DEBUG_DEFINES>
    <SQLITE_RELEASE_DEFINES>SQLITE_WIN32_MALLOC=1</SQLITE_RELEASE_DEFINES>
    <SQLITE_DISABLE_WARNINGS>4055;4100;4127;4146;4210;4232;4244;4245;4267;4306;4389;4701;4703;4706</SQLITE_DISABLE_WARNINGS>

<VisualStudioPropertySheet
	ProjectType="Visual C++"
	Version="8.00"
	Name="sqlite3"
	>
	<UserMacro
		Name="SQLITE_MANIFEST_VERSION"
		Value="3.10.2.0"
		PerformEnvironmentSet="true"
	/>
	<UserMacro
		Name="SQLITE_RC_VERSION"
		Value="3,10,2,0"
		PerformEnvironmentSet="true"
	/>
	<UserMacro
		Name="SQLITE_COMMON_DEFINES"
		Value="_CRT_SECURE_NO_DEPRECATE;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;SQLITE_THREADSAFE=1;SQLITE_USE_URI=1;SQLITE_ENABLE_COLUMN_METADATA=1;SQLITE_ENABLE_STAT4=1;SQLITE_ENABLE_FTS3=1;SQLITE_ENABLE_LOAD_EXTENSION=1;SQLITE_ENABLE_RTREE=1;SQLITE_SOUNDEX=1;SQLITE_ENABLE_MEMORY_MANAGEMENT=1;SQLITE_ENABLE_API_ARMOR=1"
		PerformEnvironmentSet="true"
	/>

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	ProjectType="Visual C++"
	Version="8.00"
	Name="sqlite3"
	>
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		Name="SQLITE_MANIFEST_VERSION"
		Value="3.11.0.0"
		PerformEnvironmentSet="true"
	/>
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		Name="SQLITE_RC_VERSION"
		Value="3,11,0,0"
		PerformEnvironmentSet="true"
	/>
	<UserMacro
		Name="SQLITE_COMMON_DEFINES"
		Value="_CRT_SECURE_NO_DEPRECATE;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;SQLITE_THREADSAFE=1;SQLITE_USE_URI=1;SQLITE_ENABLE_COLUMN_METADATA=1;SQLITE_ENABLE_STAT4=1;SQLITE_ENABLE_FTS3=1;SQLITE_ENABLE_LOAD_EXTENSION=1;SQLITE_ENABLE_RTREE=1;SQLITE_SOUNDEX=1;SQLITE_ENABLE_MEMORY_MANAGEMENT=1;SQLITE_ENABLE_API_ARMOR=1"
		PerformEnvironmentSet="true"
	/>

/******************************************************************************
** This file is an amalgamation of many separate C source files from SQLite
** version 3.10.2.  By combining all the individual C code files into this 
** single large file, the entire code can be compiled as a single translation
** unit.  This allows many compilers to do optimizations that would not be
** possible if the files were compiled separately.  Performance improvements
** of 5% or more are commonly seen when SQLite is compiled as a single
** translation unit.
**
** This file is all you need to compile SQLite.  To use SQLite in other
................................................................................
#define SQLITE_HOMEGROWN_RECURSIVE_MUTEX 1
#define SQLITE_OMIT_LOAD_EXTENSION 1
#define SQLITE_ENABLE_LOCKING_STYLE 0
#define HAVE_UTIME 1
#else
/* This is not VxWorks. */
#define OS_VXWORKS 0



#endif /* defined(_WRS_KERNEL) */

/************** End of vxworks.h *********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/

/*
** These #defines should enable >2GB file support on POSIX if the
................................................................................
** string contains the date and time of the check-in (UTC) and an SHA1
** hash of the entire source tree.
**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.10.2"
#define SQLITE_VERSION_NUMBER 3010002
#define SQLITE_SOURCE_ID      "2016-01-20 15:27:19 17efb4209f97fb4971656086b138599a91a75ff9"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
................................................................................
** ^If an error occurs while evaluating the SQL statements passed into
** sqlite3_exec(), then execution of the current statement stops and
** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
** is not NULL then any error message is written into memory obtained
** from [sqlite3_malloc()] and passed back through the 5th parameter.
** To avoid memory leaks, the application should invoke [sqlite3_free()]
** on error message strings returned through the 5th parameter of
** of sqlite3_exec() after the error message string is no longer needed.
** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
** NULL before returning.
**
** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
** routine returns SQLITE_ABORT without invoking the callback again and
** without running any subsequent SQL statements.
................................................................................
** sqlite3_libversion_number() returns a value greater than or equal to
** 3009000.
*/
struct sqlite3_index_info {
  /* Inputs */
  int nConstraint;           /* Number of entries in aConstraint */
  struct sqlite3_index_constraint {
     int iColumn;              /* Column on left-hand side of constraint */
     unsigned char op;         /* Constraint operator */
     unsigned char usable;     /* True if this constraint is usable */
     int iTermOffset;          /* Used internally - xBestIndex should ignore */
  } *aConstraint;            /* Table of WHERE clause constraints */
  int nOrderBy;              /* Number of terms in the ORDER BY clause */
  struct sqlite3_index_orderby {
     int iColumn;              /* Column number */
................................................................................
**   *pnToken to the number of tokens in column iCol of the current row.
**
**   If parameter iCol is greater than or equal to the number of columns
**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
**   an OOM condition or IO error), an appropriate SQLite error code is 
**   returned.
**



** xColumnText:
**   This function attempts to retrieve the text of column iCol of the
**   current document. If successful, (*pz) is set to point to a buffer
**   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
**   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
**   if an error occurs, an SQLite error code is returned and the final values
**   of (*pz) and (*pn) are undefined.
................................................................................
**   are numbered starting from zero.
**
** xInstCount:
**   Set *pnInst to the total number of occurrences of all phrases within
**   the query within the current row. Return SQLITE_OK if successful, or
**   an error code (i.e. SQLITE_NOMEM) if an error occurs.
**





** xInst:
**   Query for the details of phrase match iIdx within the current row.
**   Phrase matches are numbered starting from zero, so the iIdx argument
**   should be greater than or equal to zero and smaller than the value
**   output by xInstCount().






**
**   Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 
**   if an error occurs.



**
** xRowid:
**   Returns the rowid of the current row.
**
** xTokenize:
**   Tokenize text using the tokenizer belonging to the FTS5 table.
**
................................................................................
**   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
**   to use, this API may be faster under some circumstances. To iterate 
**   through instances of phrase iPhrase, use the following code:
**
**       Fts5PhraseIter iter;
**       int iCol, iOff;
**       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
**           iOff>=0;
**           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
**       ){
**         // An instance of phrase iPhrase at offset iOff of column iCol
**       }
**
**   The Fts5PhraseIter structure is defined above. Applications should not
**   modify this structure directly - it should only be used as shown above
**   with the xPhraseFirst() and xPhraseNext() API methods.

**






** xPhraseNext()
**   See xPhraseFirst above.































*/
struct Fts5ExtensionApi {
  int iVersion;                   /* Currently always set to 1 */

  void *(*xUserData)(Fts5Context*);

  int (*xColumnCount)(Fts5Context*);
  int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
  int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);

................................................................................

  int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
    int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
  );
  int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
  void *(*xGetAuxdata)(Fts5Context*, int bClear);

  void (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
  void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);



};

/* 
** CUSTOM AUXILIARY FUNCTIONS
*************************************************************************/

/*************************************************************************
................................................................................
# define ALWAYS(X)      ((X)?1:(assert(0),0))
# define NEVER(X)       ((X)?(assert(0),1):0)
#else
# define ALWAYS(X)      (X)
# define NEVER(X)       (X)
#endif
















/*
** Declarations used for tracing the operating system interfaces.
*/
#if defined(SQLITE_FORCE_OS_TRACE) || defined(SQLITE_TEST) || \
    (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)
  extern int sqlite3OSTrace;
# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
................................................................................
#endif

/*
** Default maximum size of memory used by memory-mapped I/O in the VFS
*/
#ifdef __APPLE__
# include <TargetConditionals.h>
# if TARGET_OS_IPHONE
#   undef SQLITE_MAX_MMAP_SIZE
#   define SQLITE_MAX_MMAP_SIZE 0
# endif
#endif
#ifndef SQLITE_MAX_MMAP_SIZE
# if defined(__linux__) \
  || defined(_WIN32) \
  || (defined(__APPLE__) && defined(__MACH__)) \
  || defined(__sun) \
  || defined(__FreeBSD__) \
................................................................................
#define BTREE_BULKLOAD 0x00000001  /* Used to full index in sorted order */
#define BTREE_SEEK_EQ  0x00000002  /* EQ seeks only - no range seeks */

/* 
** Flags passed as the third argument to sqlite3BtreeCursor().
**
** For read-only cursors the wrFlag argument is always zero. For read-write
** cursors it may be set to either (BTREE_WRCSR|BTREE_FORDELETE) or
** (BTREE_WRCSR). If the BTREE_FORDELETE flag is set, then the cursor will
** only be used by SQLite for the following:
**
**   * to seek to and delete specific entries, and/or
**
**   * to read values that will be used to create keys that other
**     BTREE_FORDELETE cursors will seek to and delete.










*/
#define BTREE_WRCSR     0x00000004     /* read-write cursor */
#define BTREE_FORDELETE 0x00000008     /* Cursor is for seek/delete only */

SQLITE_PRIVATE int sqlite3BtreeCursor(
  Btree*,                              /* BTree containing table to open */
  int iTable,                          /* Index of root page */
................................................................................
  UnpackedRecord *pUnKey,
  i64 intKey,
  int bias,
  int *pRes
);
SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor*);
SQLITE_PRIVATE int sqlite3BtreeCursorRestore(BtCursor*, int*);
SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor*, int);





SQLITE_PRIVATE int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
                                  const void *pData, int nData,
                                  int nZero, int bias, int seekResult);
SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor*, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor*, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor*, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor*);
................................................................................
** If we are not using shared cache, then there is no need to
** use mutexes to access the BtShared structures.  So make the
** Enter and Leave procedures no-ops.
*/
#ifndef SQLITE_OMIT_SHARED_CACHE
SQLITE_PRIVATE   void sqlite3BtreeEnter(Btree*);
SQLITE_PRIVATE   void sqlite3BtreeEnterAll(sqlite3*);


#else
# define sqlite3BtreeEnter(X) 
# define sqlite3BtreeEnterAll(X)


#endif

#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
SQLITE_PRIVATE   int sqlite3BtreeSharable(Btree*);
SQLITE_PRIVATE   void sqlite3BtreeLeave(Btree*);
SQLITE_PRIVATE   void sqlite3BtreeEnterCursor(BtCursor*);
SQLITE_PRIVATE   void sqlite3BtreeLeaveCursor(BtCursor*);
SQLITE_PRIVATE   void sqlite3BtreeLeaveAll(sqlite3*);
#ifndef NDEBUG
  /* These routines are used inside assert() statements only. */
SQLITE_PRIVATE   int sqlite3BtreeHoldsMutex(Btree*);
SQLITE_PRIVATE   int sqlite3BtreeHoldsAllMutexes(sqlite3*);
SQLITE_PRIVATE   int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);
#endif
#else

# define sqlite3BtreeSharable(X) 0
# define sqlite3BtreeLeave(X)
# define sqlite3BtreeEnterCursor(X)
# define sqlite3BtreeLeaveCursor(X)
# define sqlite3BtreeLeaveAll(X)

# define sqlite3BtreeHoldsMutex(X) 1
# define sqlite3BtreeHoldsAllMutexes(X) 1
# define sqlite3SchemaMutexHeld(X,Y,Z) 1
#endif
................................................................................
** The makefile scans the vdbe.c source file and creates the "opcodes.h"
** header file that defines a number for each opcode used by the VDBE.
*/
/************** Include opcodes.h in the middle of vdbe.h ********************/
/************** Begin file opcodes.h *****************************************/
/* Automatically generated.  Do not edit */
/* See the tool/mkopcodeh.tcl script for details */
#define OP_Savepoint       1
#define OP_AutoCommit      2
#define OP_Transaction     3
#define OP_SorterNext      4
#define OP_PrevIfOpen      5
#define OP_NextIfOpen      6
#define OP_Prev            7
#define OP_Next            8
#define OP_Checkpoint      9
#define OP_JournalMode    10
#define OP_Vacuum         11
#define OP_VFilter        12 /* synopsis: iplan=r[P3] zplan='P4'           */
#define OP_VUpdate        13 /* synopsis: data=r[P3@P2]                    */
#define OP_Goto           14
#define OP_Gosub          15
#define OP_Return         16
#define OP_InitCoroutine  17
#define OP_EndCoroutine   18

#define OP_Not            19 /* same as TK_NOT, synopsis: r[P2]= !r[P1]    */
#define OP_Yield          20
#define OP_HaltIfNull     21 /* synopsis: if r[P3]=null halt               */
#define OP_Halt           22
#define OP_Integer        23 /* synopsis: r[P2]=P1                         */
#define OP_Int64          24 /* synopsis: r[P2]=P4                         */
#define OP_String         25 /* synopsis: r[P2]='P4' (len=P1)              */
#define OP_Null           26 /* synopsis: r[P2..P3]=NULL                   */
#define OP_SoftNull       27 /* synopsis: r[P1]=NULL                       */
#define OP_Blob           28 /* synopsis: r[P2]=P4 (len=P1)                */
#define OP_Variable       29 /* synopsis: r[P2]=parameter(P1,P4)           */
#define OP_Move           30 /* synopsis: r[P2@P3]=r[P1@P3]                */
#define OP_Copy           31 /* synopsis: r[P2@P3+1]=r[P1@P3+1]            */
#define OP_SCopy          32 /* synopsis: r[P2]=r[P1]                      */
#define OP_IntCopy        33 /* synopsis: r[P2]=r[P1]                      */
#define OP_ResultRow      34 /* synopsis: output=r[P1@P2]                  */
#define OP_CollSeq        35
#define OP_Function0      36 /* synopsis: r[P3]=func(r[P2@P5])             */
#define OP_Function       37 /* synopsis: r[P3]=func(r[P2@P5])             */
#define OP_AddImm         38 /* synopsis: r[P1]=r[P1]+P2                   */
#define OP_MustBeInt      39
#define OP_RealAffinity   40
#define OP_Cast           41 /* synopsis: affinity(r[P1])                  */
#define OP_Permutation    42
#define OP_Compare        43 /* synopsis: r[P1@P3] <-> r[P2@P3]            */
#define OP_Jump           44
#define OP_Once           45
#define OP_If             46
#define OP_IfNot          47
#define OP_Column         48 /* synopsis: r[P3]=PX                         */
#define OP_Affinity       49 /* synopsis: affinity(r[P1@P2])               */
#define OP_MakeRecord     50 /* synopsis: r[P3]=mkrec(r[P1@P2])            */
#define OP_Count          51 /* synopsis: r[P2]=count()                    */
#define OP_ReadCookie     52
#define OP_SetCookie      53
#define OP_ReopenIdx      54 /* synopsis: root=P2 iDb=P3                   */
#define OP_OpenRead       55 /* synopsis: root=P2 iDb=P3                   */
#define OP_OpenWrite      56 /* synopsis: root=P2 iDb=P3                   */
#define OP_OpenAutoindex  57 /* synopsis: nColumn=P2                       */
#define OP_OpenEphemeral  58 /* synopsis: nColumn=P2                       */
#define OP_SorterOpen     59
#define OP_SequenceTest   60 /* synopsis: if( cursor[P1].ctr++ ) pc = P2   */
#define OP_OpenPseudo     61 /* synopsis: P3 columns in r[P2]              */
#define OP_Close          62
#define OP_ColumnsUsed    63
#define OP_SeekLT         64 /* synopsis: key=r[P3@P4]                     */
#define OP_SeekLE         65 /* synopsis: key=r[P3@P4]                     */
#define OP_SeekGE         66 /* synopsis: key=r[P3@P4]                     */
#define OP_SeekGT         67 /* synopsis: key=r[P3@P4]                     */
#define OP_Seek           68 /* synopsis: intkey=r[P2]                     */
#define OP_NoConflict     69 /* synopsis: key=r[P3@P4]                     */
#define OP_NotFound       70 /* synopsis: key=r[P3@P4]                     */

#define OP_Or             71 /* same as TK_OR, synopsis: r[P3]=(r[P1] || r[P2]) */
#define OP_And            72 /* same as TK_AND, synopsis: r[P3]=(r[P1] && r[P2]) */
#define OP_Found          73 /* synopsis: key=r[P3@P4]                     */
#define OP_NotExists      74 /* synopsis: intkey=r[P3]                     */
#define OP_Sequence       75 /* synopsis: r[P2]=cursor[P1].ctr++           */


#define OP_IsNull         76 /* same as TK_ISNULL, synopsis: if r[P1]==NULL goto P2 */
#define OP_NotNull        77 /* same as TK_NOTNULL, synopsis: if r[P1]!=NULL goto P2 */
#define OP_Ne             78 /* same as TK_NE, synopsis: if r[P1]!=r[P3] goto P2 */
#define OP_Eq             79 /* same as TK_EQ, synopsis: if r[P1]==r[P3] goto P2 */
#define OP_Gt             80 /* same as TK_GT, synopsis: if r[P1]>r[P3] goto P2 */
#define OP_Le             81 /* same as TK_LE, synopsis: if r[P1]<=r[P3] goto P2 */
#define OP_Lt             82 /* same as TK_LT, synopsis: if r[P1]<r[P3] goto P2 */
#define OP_Ge             83 /* same as TK_GE, synopsis: if r[P1]>=r[P3] goto P2 */
#define OP_NewRowid       84 /* synopsis: r[P2]=rowid                      */
#define OP_BitAnd         85 /* same as TK_BITAND, synopsis: r[P3]=r[P1]&r[P2] */
#define OP_BitOr          86 /* same as TK_BITOR, synopsis: r[P3]=r[P1]|r[P2] */
#define OP_ShiftLeft      87 /* same as TK_LSHIFT, synopsis: r[P3]=r[P2]<<r[P1] */
#define OP_ShiftRight     88 /* same as TK_RSHIFT, synopsis: r[P3]=r[P2]>>r[P1] */
#define OP_Add            89 /* same as TK_PLUS, synopsis: r[P3]=r[P1]+r[P2] */
#define OP_Subtract       90 /* same as TK_MINUS, synopsis: r[P3]=r[P2]-r[P1] */
#define OP_Multiply       91 /* same as TK_STAR, synopsis: r[P3]=r[P1]*r[P2] */
#define OP_Divide         92 /* same as TK_SLASH, synopsis: r[P3]=r[P2]/r[P1] */
#define OP_Remainder      93 /* same as TK_REM, synopsis: r[P3]=r[P2]%r[P1] */
#define OP_Concat         94 /* same as TK_CONCAT, synopsis: r[P3]=r[P2]+r[P1] */
#define OP_Insert         95 /* synopsis: intkey=r[P3] data=r[P2]          */
#define OP_BitNot         96 /* same as TK_BITNOT, synopsis: r[P1]= ~r[P1] */
#define OP_String8        97 /* same as TK_STRING, synopsis: r[P2]='P4'    */
#define OP_InsertInt      98 /* synopsis: intkey=P3 data=r[P2]             */
#define OP_Delete         99
#define OP_ResetCount    100
#define OP_SorterCompare 101 /* synopsis: if key(P1)!=trim(r[P3],P4) goto P2 */
#define OP_SorterData    102 /* synopsis: r[P2]=data                       */
#define OP_RowKey        103 /* synopsis: r[P2]=key                        */
#define OP_RowData       104 /* synopsis: r[P2]=data                       */
#define OP_Rowid         105 /* synopsis: r[P2]=rowid                      */
#define OP_NullRow       106
#define OP_Last          107
#define OP_SorterSort    108
#define OP_Sort          109
#define OP_Rewind        110
#define OP_SorterInsert  111
#define OP_IdxInsert     112 /* synopsis: key=r[P2]                        */
#define OP_IdxDelete     113 /* synopsis: key=r[P2@P3]                     */

#define OP_IdxRowid      114 /* synopsis: r[P2]=rowid                      */
#define OP_IdxLE         115 /* synopsis: key=r[P3@P4]                     */
#define OP_IdxGT         116 /* synopsis: key=r[P3@P4]                     */
#define OP_IdxLT         117 /* synopsis: key=r[P3@P4]                     */
#define OP_IdxGE         118 /* synopsis: key=r[P3@P4]                     */
#define OP_Destroy       119
#define OP_Clear         120
#define OP_ResetSorter   121
#define OP_CreateIndex   122 /* synopsis: r[P2]=root iDb=P1                */
#define OP_CreateTable   123 /* synopsis: r[P2]=root iDb=P1                */
#define OP_ParseSchema   124
#define OP_LoadAnalysis  125
#define OP_DropTable     126
#define OP_DropIndex     127
#define OP_DropTrigger   128
#define OP_IntegrityCk   129
#define OP_RowSetAdd     130 /* synopsis: rowset(P1)=r[P2]                 */
#define OP_RowSetRead    131 /* synopsis: r[P3]=rowset(P1)                 */
#define OP_RowSetTest    132 /* synopsis: if r[P3] in rowset(P1) goto P2   */

#define OP_Real          133 /* same as TK_FLOAT, synopsis: r[P2]=P4       */
#define OP_Program       134
#define OP_Param         135
#define OP_FkCounter     136 /* synopsis: fkctr[P1]+=P2                    */
#define OP_FkIfZero      137 /* synopsis: if fkctr[P1]==0 goto P2          */
#define OP_MemMax        138 /* synopsis: r[P1]=max(r[P1],r[P2])           */
#define OP_IfPos         139 /* synopsis: if r[P1]>0 then r[P1]-=P3, goto P2 */
#define OP_SetIfNotPos   140 /* synopsis: if r[P1]<=0 then r[P2]=P3        */

#define OP_IfNotZero     141 /* synopsis: if r[P1]!=0 then r[P1]-=P3, goto P2 */
#define OP_DecrJumpZero  142 /* synopsis: if (--r[P1])==0 goto P2          */
#define OP_JumpZeroIncr  143 /* synopsis: if (r[P1]++)==0 ) goto P2        */
#define OP_AggStep0      144 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggStep       145 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggFinal      146 /* synopsis: accum=r[P1] N=P2                 */
#define OP_IncrVacuum    147
#define OP_Expire        148
#define OP_TableLock     149 /* synopsis: iDb=P1 root=P2 write=P3          */
#define OP_VBegin        150
#define OP_VCreate       151
#define OP_VDestroy      152
#define OP_VOpen         153
#define OP_VColumn       154 /* synopsis: r[P3]=vcolumn(P2)                */
#define OP_VNext         155
#define OP_VRename       156
#define OP_Pagecount     157
#define OP_MaxPgcnt      158
#define OP_Init          159 /* synopsis: Start at P2                      */
#define OP_CursorHint    160
#define OP_Noop          161
#define OP_Explain       162

/* Properties such as "out2" or "jump" that are specified in
** comments following the "case" for each opcode in the vdbe.c
** are encoded into bitvectors as follows:
*/
#define OPFLG_JUMP            0x0001  /* jump:  P2 holds jmp target */
#define OPFLG_IN1             0x0002  /* in1:   P1 is an input */
#define OPFLG_IN2             0x0004  /* in2:   P2 is an input */
#define OPFLG_IN3             0x0008  /* in3:   P3 is an input */
#define OPFLG_OUT2            0x0010  /* out2:  P2 is an output */
#define OPFLG_OUT3            0x0020  /* out3:  P3 is an output */
#define OPFLG_INITIALIZER {\
/*   0 */ 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x01,\
/*   8 */ 0x01, 0x00, 0x10, 0x00, 0x01, 0x00, 0x01, 0x01,\
/*  16 */ 0x02, 0x01, 0x02, 0x12, 0x03, 0x08, 0x00, 0x10,\

/*  24 */ 0x10, 0x10, 0x10, 0x00, 0x10, 0x10, 0x00, 0x00,\
/*  32 */ 0x10, 0x10, 0x00, 0x00, 0x00, 0x00, 0x02, 0x03,\
/*  40 */ 0x02, 0x02, 0x00, 0x00, 0x01, 0x01, 0x03, 0x03,\
/*  48 */ 0x00, 0x00, 0x00, 0x10, 0x10, 0x08, 0x00, 0x00,\
/*  56 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/*  64 */ 0x09, 0x09, 0x09, 0x09, 0x04, 0x09, 0x09, 0x26,\
/*  72 */ 0x26, 0x09, 0x09, 0x10, 0x03, 0x03, 0x0b, 0x0b,\
/*  80 */ 0x0b, 0x0b, 0x0b, 0x0b, 0x10, 0x26, 0x26, 0x26,\
/*  88 */ 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x00,\
/*  96 */ 0x12, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 104 */ 0x00, 0x10, 0x00, 0x01, 0x01, 0x01, 0x01, 0x04,\
/* 112 */ 0x04, 0x00, 0x10, 0x01, 0x01, 0x01, 0x01, 0x10,\
/* 120 */ 0x00, 0x00, 0x10, 0x10, 0x00, 0x00, 0x00, 0x00,\
/* 128 */ 0x00, 0x00, 0x06, 0x23, 0x0b, 0x10, 0x01, 0x10,\
/* 136 */ 0x00, 0x01, 0x04, 0x03, 0x06, 0x03, 0x03, 0x03,\

/* 144 */ 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,\
/* 152 */ 0x00, 0x00, 0x00, 0x01, 0x00, 0x10, 0x10, 0x01,\
/* 160 */ 0x00, 0x00, 0x00,}

/************** End of opcodes.h *********************************************/
/************** Continuing where we left off in vdbe.h ***********************/

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
................................................................................
SQLITE_PRIVATE int sqlite3VdbeGoto(Vdbe*,int);
SQLITE_PRIVATE int sqlite3VdbeLoadString(Vdbe*,int,const char*);
SQLITE_PRIVATE void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);






SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
SQLITE_PRIVATE void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);
SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe*, int addr);
SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe*, int addr);
SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
SQLITE_PRIVATE void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe*, int);
SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeRunOnlyOnce(Vdbe*);
................................................................................

/*
** Flags for sqlite3PagerSetFlags()
*/
#define PAGER_SYNCHRONOUS_OFF       0x01  /* PRAGMA synchronous=OFF */
#define PAGER_SYNCHRONOUS_NORMAL    0x02  /* PRAGMA synchronous=NORMAL */
#define PAGER_SYNCHRONOUS_FULL      0x03  /* PRAGMA synchronous=FULL */

#define PAGER_SYNCHRONOUS_MASK      0x03  /* Mask for three values above */
#define PAGER_FULLFSYNC             0x04  /* PRAGMA fullfsync=ON */
#define PAGER_CKPT_FULLFSYNC        0x08  /* PRAGMA checkpoint_fullfsync=ON */
#define PAGER_CACHESPILL            0x10  /* PRAGMA cache_spill=ON */
#define PAGER_FLAGS_MASK            0x1c  /* All above except SYNCHRONOUS */

/*
** The remainder of this file contains the declarations of the functions
** that make up the Pager sub-system API. See source code comments for 
** a detailed description of each routine.
*/

................................................................................
#define PGHDR_DIRTY           0x002  /* Page is on the PCache.pDirty list */
#define PGHDR_WRITEABLE       0x004  /* Journaled and ready to modify */
#define PGHDR_NEED_SYNC       0x008  /* Fsync the rollback journal before
                                     ** writing this page to the database */
#define PGHDR_NEED_READ       0x010  /* Content is unread */
#define PGHDR_DONT_WRITE      0x020  /* Do not write content to disk */
#define PGHDR_MMAP            0x040  /* This is an mmap page object */



/* Initialize and shutdown the page cache subsystem */
SQLITE_PRIVATE int sqlite3PcacheInitialize(void);
SQLITE_PRIVATE void sqlite3PcacheShutdown(void);

/* Page cache buffer management:
** These routines implement SQLITE_CONFIG_PAGECACHE.
................................................................................
** with a particular database connection.  Hence, schema information cannot
** be stored in lookaside because in shared cache mode the schema information
** is shared by multiple database connections.  Therefore, while parsing
** schema information, the Lookaside.bEnabled flag is cleared so that
** lookaside allocations are not used to construct the schema objects.
*/
struct Lookaside {

  u16 sz;                 /* Size of each buffer in bytes */
  u8 bEnabled;            /* False to disable new lookaside allocations */
  u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
  int nOut;               /* Number of buffers currently checked out */
  int mxOut;              /* Highwater mark for nOut */
  int anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
  LookasideSlot *pFree;   /* List of available buffers */
  void *pStart;           /* First byte of available memory space */
  void *pEnd;             /* First byte past end of available space */
................................................................................
  int errCode;                  /* Most recent error code (SQLITE_*) */
  int errMask;                  /* & result codes with this before returning */
  u16 dbOptFlags;               /* Flags to enable/disable optimizations */
  u8 enc;                       /* Text encoding */
  u8 autoCommit;                /* The auto-commit flag. */
  u8 temp_store;                /* 1: file 2: memory 0: default */
  u8 mallocFailed;              /* True if we have seen a malloc failure */

  u8 dfltLockMode;              /* Default locking-mode for attached dbs */
  signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
  u8 suppressErr;               /* Do not issue error messages if true */
  u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
  u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
  int nextPagesize;             /* Pagesize after VACUUM if >0 */
  u32 magic;                    /* Magic number for detect library misuse */
................................................................................
#define ENC(db)        ((db)->enc)

/*
** Possible values for the sqlite3.flags.
*/
#define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
#define SQLITE_InternChanges  0x00000002  /* Uncommitted Hash table changes */

#define SQLITE_FullFSync      0x00000004  /* Use full fsync on the backend */
#define SQLITE_CkptFullFSync  0x00000008  /* Use full fsync for checkpoint */
#define SQLITE_CacheSpill     0x00000010  /* OK to spill pager cache */
#define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
#define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
#define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
                                          /*   DELETE, or UPDATE and return */
                                          /*   the count using a callback. */
#define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
                                          /*   result set is empty */
#define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
................................................................................
** points to a linked list of these structures.
*/
struct FuncDef {
  i16 nArg;            /* Number of arguments.  -1 means unlimited */
  u16 funcFlags;       /* Some combination of SQLITE_FUNC_* */
  void *pUserData;     /* User data parameter */
  FuncDef *pNext;      /* Next function with same name */
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
  void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
  void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
  char *zName;         /* SQL name of the function. */
  FuncDef *pHash;      /* Next with a different name but the same hash */
  FuncDestructor *pDestructor;   /* Reference counted destructor function */
};

/*
** This structure encapsulates a user-function destructor callback (as
................................................................................
**     function likeFunc. Argument pArg is cast to a (void *) and made
**     available as the function user-data (sqlite3_user_data()). The
**     FuncDef.flags variable is set to the value passed as the flags
**     parameter.
*/
#define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
#define VFUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
#define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
#define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
  {nArg,SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags,\
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
#define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   pArg, 0, xFunc, 0, 0, #zName, 0, 0}
#define LIKEFUNC(zName, nArg, arg, flags) \
  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|flags, \
   (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
#define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
  {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
#define AGGREGATE2(zName, nArg, arg, nc, xStep, xFinal, extraFlags) \
  {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
   SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}

/*
** All current savepoints are stored in a linked list starting at
** sqlite3.pSavepoint. The first element in the list is the most recently
** opened savepoint. Savepoints are added to the list by the vdbe
** OP_Savepoint instruction.
*/
................................................................................
};

/*
** During code generation of statements that do inserts into AUTOINCREMENT 
** tables, the following information is attached to the Table.u.autoInc.p
** pointer of each autoincrement table to record some side information that
** the code generator needs.  We have to keep per-table autoincrement
** information in case inserts are down within triggers.  Triggers do not
** normally coordinate their activities, but we do need to coordinate the
** loading and saving of autoincrement information.
*/
struct AutoincInfo {
  AutoincInfo *pNext;   /* Next info block in a list of them all */
  Table *pTab;          /* Table this info block refers to */
  int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */
................................................................................
  u8 checkSchema;      /* Causes schema cookie check after an error */
  u8 nested;           /* Number of nested calls to the parser/code generator */
  u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
  u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
  u8 mayAbort;         /* True if statement may throw an ABORT exception */
  u8 hasCompound;      /* Need to invoke convertCompoundSelectToSubquery() */
  u8 okConstFactor;    /* OK to factor out constants */

  int aTempReg[8];     /* Holding area for temporary registers */
  int nRangeReg;       /* Size of the temporary register block */
  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int nSet;            /* Number of sets used so far */
................................................................................
  /************************************************************************
  ** Above is constant between recursions.  Below is reset before and after
  ** each recursion.  The boundary between these two regions is determined
  ** using offsetof(Parse,nVar) so the nVar field must be the first field
  ** in the recursive region.
  ************************************************************************/

  int nVar;                 /* Number of '?' variables seen in the SQL so far */
  int nzVar;                /* Number of available slots in azVar[] */
  u8 iPkSortOrder;          /* ASC or DESC for INTEGER PRIMARY KEY */
  u8 explain;               /* True if the EXPLAIN flag is found on the query */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
  int nVtabLock;            /* Number of virtual tables to lock */
#endif
................................................................................
  const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
  Parse *pParse;              /* The Parse structure */
};

/*
** Bitfield flags for P5 value in various opcodes.
*/
#define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */

#define OPFLAG_EPHEM         0x01    /* OP_Column: Ephemeral output is ok */
#define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
#define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
#define OPFLAG_APPEND        0x08    /* This is likely to be an append */
#define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
#define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
#define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
#define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */
#define OPFLAG_SEEKEQ        0x02    /* OP_Open** cursor uses EQ seek only */
#define OPFLAG_FORDELETE     0x08    /* OP_Open is opening for-delete csr */
#define OPFLAG_P2ISREG       0x10    /* P2 to OP_Open** is a register number */
#define OPFLAG_PERMUTE       0x01    /* OP_Compare: use the permutation */



/*
 * Each trigger present in the database schema is stored as an instance of
 * struct Trigger. 
 *
 * Pointers to instances of struct Trigger are stored in two ways.
 * 1. In the "trigHash" hash table (part of the sqlite3* that represents the 
................................................................................
  sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
  char *zBase;         /* A base allocation.  Not from malloc. */
  char *zText;         /* The string collected so far */
  u32  nChar;          /* Length of the string so far */
  u32  nAlloc;         /* Amount of space allocated in zText */
  u32  mxAlloc;        /* Maximum allowed allocation.  0 for no malloc usage */
  u8   accError;       /* STRACCUM_NOMEM or STRACCUM_TOOBIG */
  u8   bMalloced;      /* zText points to allocated space */
};
#define STRACCUM_NOMEM   1
#define STRACCUM_TOOBIG  2







/*
** A pointer to this structure is used to communicate information
** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
*/
typedef struct {
  sqlite3 *db;        /* The database being initialized */
................................................................................
*/
#define CORRUPT_DB  (sqlite3Config.neverCorrupt==0)

/*
** Context pointer passed down through the tree-walk.
*/
struct Walker {

  int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
  int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
  void (*xSelectCallback2)(Walker*,Select*);/* Second callback for SELECTs */
  Parse *pParse;                            /* Parser context.  */
  int walkerDepth;                          /* Number of subqueries */
  u8 eCode;                                 /* A small processing code */
  union {                                   /* Extra data for callback */
    NameContext *pNC;                          /* Naming context */
    int n;                                     /* A counter */
    int iCur;                                  /* A cursor number */
    SrcList *pSrcList;                         /* FROM clause */
    struct SrcCount *pSrcCount;                /* Counting column references */
    struct CCurHint *pCCurHint;                /* Used by codeCursorHint() */

  } u;
};

/* Forward declarations */
SQLITE_PRIVATE int sqlite3WalkExpr(Walker*, Expr*);
SQLITE_PRIVATE int sqlite3WalkExprList(Walker*, ExprList*);
SQLITE_PRIVATE int sqlite3WalkSelect(Walker*, Select*);
................................................................................
SQLITE_PRIVATE int sqlite3CorruptError(int);
SQLITE_PRIVATE int sqlite3MisuseError(int);
SQLITE_PRIVATE int sqlite3CantopenError(int);
#define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
#define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
#define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)









/*
** FTS4 is really an extension for FTS3.  It is enabled using the
** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also call
** the SQLITE_ENABLE_FTS4 macro to serve as an alias for SQLITE_ENABLE_FTS3.
*/
#if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
................................................................................

SQLITE_PRIVATE int sqlite3MallocInit(void);
SQLITE_PRIVATE void sqlite3MallocEnd(void);
SQLITE_PRIVATE void *sqlite3Malloc(u64);
SQLITE_PRIVATE void *sqlite3MallocZero(u64);
SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3*, u64);
SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3*, u64);

SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3*,const char*);
SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3*,const char*, u64);
SQLITE_PRIVATE void *sqlite3Realloc(void*, u64);
SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *, void *, u64);
SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *, void *, u64);
SQLITE_PRIVATE void sqlite3DbFree(sqlite3*, void*);
SQLITE_PRIVATE int sqlite3MallocSize(void*);
................................................................................
*/
struct PrintfArguments {
  int nArg;                /* Total number of arguments */
  int nUsed;               /* Number of arguments used so far */
  sqlite3_value **apArg;   /* The argument values */
};

#define SQLITE_PRINTF_INTERNAL 0x01
#define SQLITE_PRINTF_SQLFUNC  0x02
SQLITE_PRIVATE void sqlite3VXPrintf(StrAccum*, u32, const char*, va_list);
SQLITE_PRIVATE void sqlite3XPrintf(StrAccum*, u32, const char*, ...);
SQLITE_PRIVATE char *sqlite3MPrintf(sqlite3*,const char*, ...);
SQLITE_PRIVATE char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
SQLITE_PRIVATE   void sqlite3DebugPrintf(const char*, ...);
#endif
#if defined(SQLITE_TEST)
SQLITE_PRIVATE   void *sqlite3TestTextToPtr(const char*);
................................................................................
SQLITE_PRIVATE   void sqlite3TreeViewWith(TreeView*, const With*, u8);
#endif


SQLITE_PRIVATE void sqlite3SetString(char **, sqlite3*, const char*);
SQLITE_PRIVATE void sqlite3ErrorMsg(Parse*, const char*, ...);
SQLITE_PRIVATE int sqlite3Dequote(char*);

SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char*, int);
SQLITE_PRIVATE int sqlite3RunParser(Parse*, const char*, char **);
SQLITE_PRIVATE void sqlite3FinishCoding(Parse*);
SQLITE_PRIVATE int sqlite3GetTempReg(Parse*);
SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse*,int);
SQLITE_PRIVATE int sqlite3GetTempRange(Parse*,int);
SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse*,int,int);
................................................................................
SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList*);
SQLITE_PRIVATE int sqlite3Init(sqlite3*, char**);
SQLITE_PRIVATE int sqlite3InitCallback(void*, int, char**, char**);
SQLITE_PRIVATE void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
SQLITE_PRIVATE void sqlite3ResetAllSchemasOfConnection(sqlite3*);
SQLITE_PRIVATE void sqlite3ResetOneSchema(sqlite3*,int);
SQLITE_PRIVATE void sqlite3CollapseDatabaseArray(sqlite3*);
SQLITE_PRIVATE void sqlite3BeginParse(Parse*,int);
SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3*);
SQLITE_PRIVATE void sqlite3DeleteColumnNames(sqlite3*,Table*);
SQLITE_PRIVATE int sqlite3ColumnsFromExprList(Parse*,ExprList*,i16*,Column**);
SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse*,Select*);
SQLITE_PRIVATE void sqlite3OpenMasterTable(Parse *, int);
SQLITE_PRIVATE Index *sqlite3PrimaryKeyIndex(Table*);
SQLITE_PRIVATE i16 sqlite3ColumnOfIndex(Index*, i16);
................................................................................
SQLITE_PRIVATE int sqlite3IsRowid(const char*);
SQLITE_PRIVATE void sqlite3GenerateRowDelete(
    Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8,int);
SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*, int);
SQLITE_PRIVATE int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);
SQLITE_PRIVATE void sqlite3ResolvePartIdxLabel(Parse*,int);
SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(Parse*,Table*,int*,int,int,int,int,
                                     u8,u8,int,int*);
SQLITE_PRIVATE void sqlite3CompleteInsertion(Parse*,Table*,int,int,int,int*,int,int,int);
SQLITE_PRIVATE int sqlite3OpenTableAndIndices(Parse*, Table*, int, u8, int, u8*, int*, int*);
SQLITE_PRIVATE void sqlite3BeginWriteOperation(Parse*, int, int);
SQLITE_PRIVATE void sqlite3MultiWrite(Parse*);
SQLITE_PRIVATE void sqlite3MayAbort(Parse*);
SQLITE_PRIVATE void sqlite3HaltConstraint(Parse*, int, int, char*, i8, u8);
SQLITE_PRIVATE void sqlite3UniqueConstraint(Parse*, int, Index*);
................................................................................
SQLITE_PRIVATE int sqlite3FindDb(sqlite3*, Token*);
SQLITE_PRIVATE int sqlite3FindDbName(sqlite3 *, const char *);
SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3*,int iDB);
SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3*,Index*);
SQLITE_PRIVATE void sqlite3DefaultRowEst(Index*);
SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3*, int);
SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
SQLITE_PRIVATE void sqlite3MinimumFileFormat(Parse*, int, int);
SQLITE_PRIVATE void sqlite3SchemaClear(void *);
SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3*,int,int);
SQLITE_PRIVATE void sqlite3KeyInfoUnref(KeyInfo*);
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoRef(KeyInfo*);
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoOfIndex(Parse*, Index*);
................................................................................
SQLITE_PRIVATE int sqlite3KeyInfoIsWriteable(KeyInfo*);
#endif
SQLITE_PRIVATE int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *, 
  void (*)(sqlite3_context*,int,sqlite3_value **),
  void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
  FuncDestructor *pDestructor
);


SQLITE_PRIVATE int sqlite3ApiExit(sqlite3 *db, int);
SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *);

SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
SQLITE_PRIVATE void sqlite3StrAccumAppend(StrAccum*,const char*,int);
SQLITE_PRIVATE void sqlite3StrAccumAppendAll(StrAccum*,const char*);
SQLITE_PRIVATE void sqlite3AppendChar(StrAccum*,int,char);
................................................................................
**      * A b-tree cursor
**          -  In the main database or in an ephemeral database
**          -  On either an index or a table
**      * A sorter
**      * A virtual table
**      * A one-row "pseudotable" stored in a single register
*/

struct VdbeCursor {
  u8 eCurType;          /* One of the CURTYPE_* values above */
  i8 iDb;               /* Index of cursor database in db->aDb[] (or -1) */
  u8 nullRow;           /* True if pointing to a row with no data */
  u8 deferredMoveto;    /* A call to sqlite3BtreeMoveto() is needed */
  u8 isTable;           /* True for rowid tables.  False for indexes */
#ifdef SQLITE_DEBUG
  u8 seekOp;            /* Most recent seek operation on this cursor */

#endif
  Bool isEphemeral:1;   /* True for an ephemeral table */
  Bool useRandomRowid:1;/* Generate new record numbers semi-randomly */
  Bool isOrdered:1;     /* True if the underlying table is BTREE_UNORDERED */
  Pgno pgnoRoot;        /* Root page of the open btree cursor */
  i16 nField;           /* Number of fields in the header */
  u16 nHdrParsed;       /* Number of header fields parsed so far */
................................................................................
    VdbeSorter *pSorter;        /* CURTYPE_SORTER. Sorter object */
  } uc;
  Btree *pBt;           /* Separate file holding temporary table */
  KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
  int seekResult;       /* Result of previous sqlite3BtreeMoveto() */
  i64 seqCount;         /* Sequence counter */
  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */


#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
  u64 maskUsed;         /* Mask of columns used by this cursor */
#endif

  /* Cached information about the header for the data record that the
  ** cursor is currently pointing to.  Only valid if cacheStatus matches
  ** Vdbe.cacheCtr.  Vdbe.cacheCtr will never take on the value of
................................................................................
  const u8 *aRow;       /* Data for the current row, if all on one page */
  u32 *aOffset;         /* Pointer to aType[nField] */
  u32 aType[1];         /* Type values for all entries in the record */
  /* 2*nField extra array elements allocated for aType[], beyond the one
  ** static element declared in the structure.  nField total array slots for
  ** aType[] and nField+1 array slots for aOffset[] */
};
typedef struct VdbeCursor VdbeCursor;

/*
** When a sub-program is executed (OP_Program), a structure of this type
** is allocated to store the current value of the program counter, as
** well as the current memory cell array and various other frame specific
** values stored in the Vdbe struct. When the sub-program is finished, 
** these values are copied back to the Vdbe from the VdbeFrame structure,
................................................................................
#define MEM_Real      0x0008   /* Value is a real number */
#define MEM_Blob      0x0010   /* Value is a BLOB */
#define MEM_AffMask   0x001f   /* Mask of affinity bits */
#define MEM_RowSet    0x0020   /* Value is a RowSet object */
#define MEM_Frame     0x0040   /* Value is a VdbeFrame object */
#define MEM_Undefined 0x0080   /* Value is undefined */
#define MEM_Cleared   0x0100   /* NULL set by OP_Null, not from data */
#define MEM_TypeMask  0x01ff   /* Mask of type bits */


/* Whenever Mem contains a valid string or blob representation, one of
** the following flags must be set to determine the memory management
** policy for Mem.z.  The MEM_Term flag tells us whether or not the
** string is \000 or \u0000 terminated
*/
#define MEM_Term      0x0200   /* String rep is nul terminated */
#define MEM_Dyn       0x0400   /* Need to call Mem.xDel() on Mem.z */
#define MEM_Static    0x0800   /* Mem.z points to a static string */
#define MEM_Ephem     0x1000   /* Mem.z points to an ephemeral string */
#define MEM_Agg       0x2000   /* Mem.z points to an agg function context */
#define MEM_Zero      0x4000   /* Mem.i contains count of 0s appended to blob */

#ifdef SQLITE_OMIT_INCRBLOB
  #undef MEM_Zero
  #define MEM_Zero 0x0000
#endif







/*
** Clear any existing type flags from a Mem and replace them with f
*/
#define MemSetTypeFlag(p, f) \
   ((p)->flags = ((p)->flags&~(MEM_TypeMask|MEM_Zero))|f)

................................................................................

/*
** Function prototypes
*/
SQLITE_PRIVATE void sqlite3VdbeError(Vdbe*, const char *, ...);
SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);
void sqliteVdbePopStack(Vdbe*,int);
SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor*);
SQLITE_PRIVATE int sqlite3VdbeCursorRestore(VdbeCursor*);
#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE*, int, Op*);
#endif
SQLITE_PRIVATE u32 sqlite3VdbeSerialTypeLen(u32);
SQLITE_PRIVATE u8 sqlite3VdbeOneByteSerialTypeLen(u8);
SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem*, int, u32*);
................................................................................
SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem*);
SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemRealify(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem*);
SQLITE_PRIVATE void sqlite3VdbeMemCast(Mem*,u8,u8);
SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,u32,u32,int,Mem*);
SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p);
#define VdbeMemDynamic(X)  \
  (((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame))!=0)
SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
SQLITE_PRIVATE const char *sqlite3OpcodeName(int);
SQLITE_PRIVATE int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int n);
SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *, int);
SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame*);
SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *);
................................................................................
SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(const VdbeCursor *, Mem *);
SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *, const VdbeCursor *, int *);
SQLITE_PRIVATE int sqlite3VdbeSorterRewind(const VdbeCursor *, int *);
SQLITE_PRIVATE int sqlite3VdbeSorterWrite(const VdbeCursor *, Mem *);
SQLITE_PRIVATE int sqlite3VdbeSorterCompare(const VdbeCursor *, Mem *, int, int *);

#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
SQLITE_PRIVATE   void sqlite3VdbeEnter(Vdbe*);
SQLITE_PRIVATE   void sqlite3VdbeLeave(Vdbe*);
#else
# define sqlite3VdbeEnter(X)





# define sqlite3VdbeLeave(X)
#endif

#ifdef SQLITE_DEBUG
SQLITE_PRIVATE void sqlite3VdbeMemAboutToChange(Vdbe*,Mem*);
SQLITE_PRIVATE int sqlite3VdbeCheckMemInvariants(Mem*);
#endif
................................................................................
  char validJD;      /* True (1) if iJD is valid */
  char validTZ;      /* True (1) if tz is valid */
  char tzSet;        /* Timezone was set explicitly */
};


/*
** Convert zDate into one or more integers.  Additional arguments
** come in groups of 5 as follows:
**
**       N       number of digits in the integer
**       min     minimum allowed value of the integer
**       max     maximum allowed value of the integer
**       nextC   first character after the integer
**       pVal    where to write the integers value.










**
** Conversions continue until one with nextC==0 is encountered.





** The function returns the number of successful conversions.
*/
static int getDigits(const char *zDate, ...){



  va_list ap;
  int val;
  int N;
  int min;
  int max;
  int nextC;
  int *pVal;
  int cnt = 0;
  va_start(ap, zDate);
  do{
    N = va_arg(ap, int);
    min = va_arg(ap, int);
    max = va_arg(ap, int);







    nextC = va_arg(ap, int);
    pVal = va_arg(ap, int*);
    val = 0;
    while( N-- ){
      if( !sqlite3Isdigit(*zDate) ){
        goto end_getDigits;
      }
      val = val*10 + *zDate - '0';
      zDate++;
    }
    if( val<min || val>max || (nextC!=0 && nextC!=*zDate) ){
      goto end_getDigits;
    }
    *pVal = val;
    zDate++;
    cnt++;

  }while( nextC );
end_getDigits:
  va_end(ap);
  return cnt;
}

/*
................................................................................
  }else if( c=='Z' || c=='z' ){
    zDate++;
    goto zulu_time;
  }else{
    return c!=0;
  }
  zDate++;
  if( getDigits(zDate, 2, 0, 14, ':', &nHr, 2, 0, 59, 0, &nMn)!=2 ){
    return 1;
  }
  zDate += 5;
  p->tz = sgn*(nMn + nHr*60);
zulu_time:
  while( sqlite3Isspace(*zDate) ){ zDate++; }
  p->tzSet = 1;
................................................................................
** fractional seconds FFFF can be one or more digits.
**
** Return 1 if there is a parsing error and 0 on success.
*/
static int parseHhMmSs(const char *zDate, DateTime *p){
  int h, m, s;
  double ms = 0.0;
  if( getDigits(zDate, 2, 0, 24, ':', &h, 2, 0, 59, 0, &m)!=2 ){
    return 1;
  }
  zDate += 5;
  if( *zDate==':' ){
    zDate++;
    if( getDigits(zDate, 2, 0, 59, 0, &s)!=1 ){
      return 1;
    }
    zDate += 2;
    if( *zDate=='.' && sqlite3Isdigit(zDate[1]) ){
      double rScale = 1.0;
      zDate++;
      while( sqlite3Isdigit(*zDate) ){
................................................................................

  if( zDate[0]=='-' ){
    zDate++;
    neg = 1;
  }else{
    neg = 0;
  }
  if( getDigits(zDate,4,0,9999,'-',&Y,2,1,12,'-',&M,2,1,31,0,&D)!=3 ){
    return 1;
  }
  zDate += 10;
  while( sqlite3Isspace(*zDate) || 'T'==*(u8*)zDate ){ zDate++; }
  if( parseHhMmSs(zDate, p)==0 ){
    /* We got the time */
  }else if( *zDate==0 ){
................................................................................
  testcase( n==(u64)db->aLimit[SQLITE_LIMIT_LENGTH] );
  if( n<sizeof(zBuf) ){
    z = zBuf;
  }else if( n>(u64)db->aLimit[SQLITE_LIMIT_LENGTH] ){
    sqlite3_result_error_toobig(context);
    return;
  }else{
    z = sqlite3DbMallocRaw(db, (int)n);
    if( z==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
  }
  computeJD(&x);
  computeYMD_HMS(&x);
................................................................................
** This file contains OS interface code that is common to all
** architectures.
*/
#define _SQLITE_OS_C_ 1
/* #include "sqliteInt.h" */
#undef _SQLITE_OS_C_























/*
** The default SQLite sqlite3_vfs implementations do not allocate
** memory (actually, os_unix.c allocates a small amount of memory
** from within OsOpen()), but some third-party implementations may.
** So we test the effects of a malloc() failing and the sqlite3OsXXX()
** function returning SQLITE_IOERR_NOMEM using the DO_OS_MALLOC_TEST macro.
**
** The following functions are instrumented for malloc() failure 
** testing:
**
**     sqlite3OsRead()
**     sqlite3OsWrite()
**     sqlite3OsSync()
**     sqlite3OsFileSize()
**     sqlite3OsLock()
................................................................................
** is only a hint and can be safely ignored.  The sqlite3OsFileControlHint()
** routine has no return value since the return value would be meaningless.
*/
SQLITE_PRIVATE int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){
#ifdef SQLITE_TEST
  if( op!=SQLITE_FCNTL_COMMIT_PHASETWO ){
    /* Faults are not injected into COMMIT_PHASETWO because, assuming SQLite
    ** is using a regular VFS, it is called after the corresponding 
    ** transaction has been committed. Injecting a fault at this point 
    ** confuses the test scripts - the COMMIT comand returns SQLITE_NOMEM
    ** but the transaction is committed anyway.
    **
    ** The core must call OsFileControl() though, not OsFileControlHint(),
    ** as if a custom VFS (e.g. zipvfs) returns an error here, it probably
    ** means the commit really has failed and an error should be returned
    ** to the user.  */
................................................................................
#endif

/*
** The next group of routines are convenience wrappers around the
** VFS methods.
*/
SQLITE_PRIVATE int sqlite3OsOpen(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  sqlite3_file *pFile, 
  int flags, 
  int *pFlagsOut
){
  int rc;
  DO_OS_MALLOC_TEST(0);
  /* 0x87f7f is a mask of SQLITE_OPEN_ flags that are valid to be passed
  ** down into the VFS layer.  Some SQLITE_OPEN_ flags (for example,
  ** SQLITE_OPEN_FULLMUTEX or SQLITE_OPEN_SHAREDCACHE) are blocked before
................................................................................
}
SQLITE_PRIVATE int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  DO_OS_MALLOC_TEST(0);
  assert( dirSync==0 || dirSync==1 );
  return pVfs->xDelete(pVfs, zPath, dirSync);
}
SQLITE_PRIVATE int sqlite3OsAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int flags, 
  int *pResOut
){
  DO_OS_MALLOC_TEST(0);
  return pVfs->xAccess(pVfs, zPath, flags, pResOut);
}
SQLITE_PRIVATE int sqlite3OsFullPathname(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int nPathOut, 
  char *zPathOut
){
  DO_OS_MALLOC_TEST(0);
  zPathOut[0] = 0;
  return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
}
#ifndef SQLITE_OMIT_LOAD_EXTENSION
................................................................................
    rc = pVfs->xCurrentTime(pVfs, &r);
    *pTimeOut = (sqlite3_int64)(r*86400000.0);
  }
  return rc;
}

SQLITE_PRIVATE int sqlite3OsOpenMalloc(
  sqlite3_vfs *pVfs, 
  const char *zFile, 
  sqlite3_file **ppFile, 
  int flags,
  int *pOutFlags
){
  int rc = SQLITE_NOMEM;
  sqlite3_file *pFile;
  pFile = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile);
  if( pFile ){
................................................................................
  u8 *zPool;       /* Memory available to be allocated */
  
  /*
  ** Mutex to control access to the memory allocation subsystem.
  */
  sqlite3_mutex *mutex;


  /*
  ** Performance statistics
  */
  u64 nAlloc;         /* Total number of calls to malloc */
  u64 totalAlloc;     /* Total of all malloc calls - includes internal frag */
  u64 totalExcess;    /* Total internal fragmentation */
  u32 currentOut;     /* Current checkout, including internal fragmentation */
  u32 currentCount;   /* Current number of distinct checkouts */
  u32 maxOut;         /* Maximum instantaneous currentOut */
  u32 maxCount;       /* Maximum instantaneous currentCount */
  u32 maxRequest;     /* Largest allocation (exclusive of internal frag) */

  
  /*
  ** Lists of free blocks.  aiFreelist[0] is a list of free blocks of
  ** size mem5.szAtom.  aiFreelist[1] holds blocks of size szAtom*2.
  ** aiFreelist[2] holds free blocks of size szAtom*4.  And so forth.
  */
  int aiFreelist[LOGMAX+1];
................................................................................
  int iBin;        /* Index into mem5.aiFreelist[] */
  int iFullSz;     /* Size of allocation rounded up to power of 2 */
  int iLogsize;    /* Log2 of iFullSz/POW2_MIN */

  /* nByte must be a positive */
  assert( nByte>0 );





  /* Keep track of the maximum allocation request.  Even unfulfilled
  ** requests are counted */
  if( (u32)nByte>mem5.maxRequest ){
    /* Abort if the requested allocation size is larger than the largest
    ** power of two that we can represent using 32-bit signed integers. */
    if( nByte > 0x40000000 ) return 0;
    mem5.maxRequest = nByte;
  }



  /* Round nByte up to the next valid power of two */
  for(iFullSz=mem5.szAtom,iLogsize=0; iFullSz<nByte; iFullSz*=2,iLogsize++){}

  /* Make sure mem5.aiFreelist[iLogsize] contains at least one free
  ** block.  If not, then split a block of the next larger power of
  ** two in order to create a new free block of size iLogsize.
................................................................................
    iBin--;
    newSize = 1 << iBin;
    mem5.aCtrl[i+newSize] = CTRL_FREE | iBin;
    memsys5Link(i+newSize, iBin);
  }
  mem5.aCtrl[i] = iLogsize;


  /* Update allocator performance statistics. */
  mem5.nAlloc++;
  mem5.totalAlloc += iFullSz;
  mem5.totalExcess += iFullSz - nByte;
  mem5.currentCount++;
  mem5.currentOut += iFullSz;
  if( mem5.maxCount<mem5.currentCount ) mem5.maxCount = mem5.currentCount;
  if( mem5.maxOut<mem5.currentOut ) mem5.maxOut = mem5.currentOut;


#ifdef SQLITE_DEBUG
  /* Make sure the allocated memory does not assume that it is set to zero
  ** or retains a value from a previous allocation */
  memset(&mem5.zPool[i*mem5.szAtom], 0xAA, iFullSz);
#endif

................................................................................

  iLogsize = mem5.aCtrl[iBlock] & CTRL_LOGSIZE;
  size = 1<<iLogsize;
  assert( iBlock+size-1<(u32)mem5.nBlock );

  mem5.aCtrl[iBlock] |= CTRL_FREE;
  mem5.aCtrl[iBlock+size-1] |= CTRL_FREE;


  assert( mem5.currentCount>0 );
  assert( mem5.currentOut>=(size*mem5.szAtom) );
  mem5.currentCount--;
  mem5.currentOut -= size*mem5.szAtom;
  assert( mem5.currentOut>0 || mem5.currentCount==0 );
  assert( mem5.currentCount>0 || mem5.currentOut==0 );


  mem5.aCtrl[iBlock] = CTRL_FREE | iLogsize;
  while( ALWAYS(iLogsize<LOGMAX) ){
    int iBuddy;
    if( (iBlock>>iLogsize) & 1 ){
      iBuddy = iBlock - size;

    }else{
      iBuddy = iBlock + size;

    }
    assert( iBuddy>=0 );
    if( (iBuddy+(1<<iLogsize))>mem5.nBlock ) break;
    if( mem5.aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;
    memsys5Unlink(iBuddy, iLogsize);
    iLogsize++;
    if( iBuddy<iBlock ){
      mem5.aCtrl[iBuddy] = CTRL_FREE | iLogsize;
      mem5.aCtrl[iBlock] = 0;
      iBlock = iBuddy;
................................................................................

/*
** Macros for performance tracing.  Normally turned off.  Only works
** on i486 hardware.
*/
#ifdef SQLITE_PERFORMANCE_TRACE

/* 
** hwtime.h contains inline assembler code for implementing 
** high-performance timing routines.
*/
/************** Include hwtime.h in the middle of os_common.h ****************/
/************** Begin file hwtime.h ******************************************/
/*
** 2008 May 27
**
................................................................................
#endif

/*
** If we compile with the SQLITE_TEST macro set, then the following block
** of code will give us the ability to simulate a disk I/O error.  This
** is used for testing the I/O recovery logic.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
SQLITE_API int sqlite3_diskfull_pending = 0;
SQLITE_API int sqlite3_diskfull = 0;
#define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
#define SimulateIOError(CODE)  \
  if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
       || sqlite3_io_error_pending-- == 1 )  \
              { local_ioerr(); CODE; }
static void local_ioerr(){
  IOTRACE(("IOERR\n"));
................................................................................
       sqlite3_diskfull_pending--; \
     } \
   }
#else
#define SimulateIOErrorBenign(X)
#define SimulateIOError(A)
#define SimulateDiskfullError(A)
#endif

/*
** When testing, keep a count of the number of open files.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_open_file_count = 0;
#define OpenCounter(X)  sqlite3_open_file_count+=(X)
#else
#define OpenCounter(X)
#endif

#endif /* !defined(_OS_COMMON_H_) */

/************** End of os_common.h *******************************************/
/************** Continuing where we left off in mutex_w32.c ******************/

/*
................................................................................
}

/*
** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
*/
SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3 *db, u64 n){


  void *p = sqlite3DbMallocRaw(db, n);
  if( p ){
    memset(p, 0, (size_t)n);

  }












  return p;
}

/*

** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
**
** If db!=0 and db->mallocFailed is true (indicating a prior malloc
** failure on the same database connection) then always return 0.
** Hence for a particular database connection, once malloc starts
** failing, it fails consistently until mallocFailed is reset.
** This is an important assumption.  There are many places in the
** code that do things like this:
................................................................................
**
**         int *a = (int*)sqlite3DbMallocRaw(db, 100);
**         int *b = (int*)sqlite3DbMallocRaw(db, 200);
**         if( b ) a[10] = 9;
**
** In other words, if a subsequent malloc (ex: "b") worked, it is assumed
** that all prior mallocs (ex: "a") worked too.



*/
SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3 *db, u64 n){
  void *p;
  assert( db==0 || sqlite3_mutex_held(db->mutex) );
  assert( db==0 || db->pnBytesFreed==0 );




#ifndef SQLITE_OMIT_LOOKASIDE
  if( db ){
    LookasideSlot *pBuf;




    if( db->mallocFailed ){
      return 0;
    }
    if( db->lookaside.bEnabled ){
      if( n>db->lookaside.sz ){
        db->lookaside.anStat[1]++;
      }else if( (pBuf = db->lookaside.pFree)==0 ){
        db->lookaside.anStat[2]++;
      }else{
        db->lookaside.pFree = pBuf->pNext;
        db->lookaside.nOut++;
        db->lookaside.anStat[0]++;
        if( db->lookaside.nOut>db->lookaside.mxOut ){
          db->lookaside.mxOut = db->lookaside.nOut;
        }
        return (void*)pBuf;
      }


    }
  }
#else



  if( db && db->mallocFailed ){
    return 0;
  }
#endif
  p = sqlite3Malloc(n);
  if( !p && db ){
    db->mallocFailed = 1;

  }
  sqlite3MemdebugSetType(p, 
         (db && db->lookaside.bEnabled) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP);
  return p;
}



/*
** Resize the block of memory pointed to by p to n bytes. If the
** resize fails, set the mallocFailed flag in the connection object.
*/
SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){
  void *pNew = 0;
  assert( db!=0 );

  assert( sqlite3_mutex_held(db->mutex) );
  if( db->mallocFailed==0 ){
    if( p==0 ){
      return sqlite3DbMallocRaw(db, n);


    }





    if( isLookaside(db, p) ){
      if( n<=db->lookaside.sz ){
        return p;
      }
      pNew = sqlite3DbMallocRaw(db, n);
      if( pNew ){
        memcpy(pNew, p, db->lookaside.sz);
        sqlite3DbFree(db, p);
      }
    }else{
      assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
      assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
      sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
      pNew = sqlite3_realloc64(p, n);
      if( !pNew ){
        db->mallocFailed = 1;
      }
      sqlite3MemdebugSetType(pNew,
            (db->lookaside.bEnabled ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));
    }
  }
  return pNew;
}

/*
** Attempt to reallocate p.  If the reallocation fails, then free p
................................................................................
  if( zNew ){
    memcpy(zNew, z, n);
  }
  return zNew;
}
SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){
  char *zNew;

  if( z==0 ){
    return 0;
  }
  assert( (n&0x7fffffff)==n );
  zNew = sqlite3DbMallocRaw(db, n+1);
  if( zNew ){
    memcpy(zNew, z, (size_t)n);
    zNew[n] = 0;
  }
  return zNew;
}

................................................................................
/*
** Free any prior content in *pz and replace it with a copy of zNew.
*/
SQLITE_PRIVATE void sqlite3SetString(char **pz, sqlite3 *db, const char *zNew){
  sqlite3DbFree(db, *pz);
  *pz = sqlite3DbStrDup(db, zNew);
}

































/*
** Take actions at the end of an API call to indicate an OOM error
*/
static SQLITE_NOINLINE int apiOomError(sqlite3 *db){
  db->mallocFailed = 0;
  sqlite3Error(db, SQLITE_NOMEM);
  return SQLITE_NOMEM;
}

/*
** This function must be called before exiting any API function (i.e. 
** returning control to the user) that has called sqlite3_malloc or
................................................................................
#define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */

/*
** Render a string given by "fmt" into the StrAccum object.
*/
SQLITE_PRIVATE void sqlite3VXPrintf(
  StrAccum *pAccum,          /* Accumulate results here */
  u32 bFlags,                /* SQLITE_PRINTF_* flags */
  const char *fmt,           /* Format string */
  va_list ap                 /* arguments */
){
  int c;                     /* Next character in the format string */
  char *bufpt;               /* Pointer to the conversion buffer */
  int precision;             /* Precision of the current field */
  int length;                /* Length of the field */
................................................................................
  etByte flag_dp;            /* True if decimal point should be shown */
  etByte flag_rtz;           /* True if trailing zeros should be removed */
#endif
  PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
  char buf[etBUFSIZE];       /* Conversion buffer */

  bufpt = 0;
  if( bFlags ){
    if( (bArgList = (bFlags & SQLITE_PRINTF_SQLFUNC))!=0 ){
      pArgList = va_arg(ap, PrintfArguments*);
    }
    useIntern = bFlags & SQLITE_PRINTF_INTERNAL;
  }else{
    bArgList = useIntern = 0;
  }
  for(; (c=(*fmt))!=0; ++fmt){
    if( c!='%' ){
      bufpt = (char *)fmt;
#if HAVE_STRCHRNUL
................................................................................
    return 0;
  }
  if( p->mxAlloc==0 ){
    N = p->nAlloc - p->nChar - 1;
    setStrAccumError(p, STRACCUM_TOOBIG);
    return N;
  }else{
    char *zOld = p->bMalloced ? p->zText : 0;
    i64 szNew = p->nChar;
    assert( (p->zText==0 || p->zText==p->zBase)==(p->bMalloced==0) );
    szNew += N + 1;
    if( szNew+p->nChar<=p->mxAlloc ){
      /* Force exponential buffer size growth as long as it does not overflow,
      ** to avoid having to call this routine too often */
      szNew += p->nChar;
    }
    if( szNew > p->mxAlloc ){
................................................................................
    if( p->db ){
      zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);
    }else{
      zNew = sqlite3_realloc64(zOld, p->nAlloc);
    }
    if( zNew ){
      assert( p->zText!=0 || p->nChar==0 );
      if( !p->bMalloced && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
      p->zText = zNew;
      p->nAlloc = sqlite3DbMallocSize(p->db, zNew);
      p->bMalloced = 1;
    }else{
      sqlite3StrAccumReset(p);
      setStrAccumError(p, STRACCUM_NOMEM);
      return 0;
    }
  }
  return N;
................................................................................
** Append N copies of character c to the given string buffer.
*/
SQLITE_PRIVATE void sqlite3AppendChar(StrAccum *p, int N, char c){
  testcase( p->nChar + (i64)N > 0x7fffffff );
  if( p->nChar+(i64)N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ){
    return;
  }
  assert( (p->zText==p->zBase)==(p->bMalloced==0) );
  while( (N--)>0 ) p->zText[p->nChar++] = c;
}

/*
** The StrAccum "p" is not large enough to accept N new bytes of z[].
** So enlarge if first, then do the append.
**
................................................................................
*/
static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){
  N = sqlite3StrAccumEnlarge(p, N);
  if( N>0 ){
    memcpy(&p->zText[p->nChar], z, N);
    p->nChar += N;
  }
  assert( (p->zText==0 || p->zText==p->zBase)==(p->bMalloced==0) );
}

/*
** Append N bytes of text from z to the StrAccum object.  Increase the
** size of the memory allocation for StrAccum if necessary.
*/
SQLITE_PRIVATE void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
................................................................................
/*
** Finish off a string by making sure it is zero-terminated.
** Return a pointer to the resulting string.  Return a NULL
** pointer if any kind of error was encountered.
*/
SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum *p){
  if( p->zText ){
    assert( (p->zText==p->zBase)==(p->bMalloced==0) );
    p->zText[p->nChar] = 0;
    if( p->mxAlloc>0 && p->bMalloced==0 ){
      p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
      if( p->zText ){
        memcpy(p->zText, p->zBase, p->nChar+1);
        p->bMalloced = 1;
      }else{
        setStrAccumError(p, STRACCUM_NOMEM);
      }
    }
  }
  return p->zText;
}

/*
** Reset an StrAccum string.  Reclaim all malloced memory.
*/
SQLITE_PRIVATE void sqlite3StrAccumReset(StrAccum *p){
  assert( (p->zText==0 || p->zText==p->zBase)==(p->bMalloced==0) );
  if( p->bMalloced ){
    sqlite3DbFree(p->db, p->zText);
    p->bMalloced = 0;
  }
  p->zText = 0;
}

/*
** Initialize a string accumulator.
**
................................................................................
SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum *p, sqlite3 *db, char *zBase, int n, int mx){
  p->zText = p->zBase = zBase;
  p->db = db;
  p->nChar = 0;
  p->nAlloc = n;
  p->mxAlloc = mx;
  p->accError = 0;
  p->bMalloced = 0;
}

/*
** Print into memory obtained from sqliteMalloc().  Use the internal
** %-conversion extensions.
*/
SQLITE_PRIVATE char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
  char *z;
  char zBase[SQLITE_PRINT_BUF_SIZE];
  StrAccum acc;
  assert( db!=0 );
  sqlite3StrAccumInit(&acc, db, zBase, sizeof(zBase),
                      db->aLimit[SQLITE_LIMIT_LENGTH]);

  sqlite3VXPrintf(&acc, SQLITE_PRINTF_INTERNAL, zFormat, ap);
  z = sqlite3StrAccumFinish(&acc);
  if( acc.accError==STRACCUM_NOMEM ){
    db->mallocFailed = 1;

  }
  return z;
}

/*
** Print into memory obtained from sqliteMalloc().  Use the internal
** %-conversion extensions.
................................................................................
    return 0;
  }
#endif
#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  sqlite3StrAccumInit(&acc, 0, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  z = sqlite3StrAccumFinish(&acc);
  return z;
}

/*
** Print into memory obtained from sqlite3_malloc()().  Omit the internal
** %-conversion extensions.
................................................................................
  if( zBuf==0 || zFormat==0 ) {
    (void)SQLITE_MISUSE_BKPT;
    if( zBuf ) zBuf[0] = 0;
    return zBuf;
  }
#endif
  sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  return sqlite3StrAccumFinish(&acc);
}
SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
  char *z;
  va_list ap;
  va_start(ap,zFormat);
  z = sqlite3_vsnprintf(n, zBuf, zFormat, ap);
................................................................................
** memory mutex is held do not use these mechanisms.
*/
static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
  StrAccum acc;                          /* String accumulator */
  char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */

  sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  sqlite3GlobalConfig.xLog(sqlite3GlobalConfig.pLogArg, iErrCode,
                           sqlite3StrAccumFinish(&acc));
}

/*
** Format and write a message to the log if logging is enabled.
*/
................................................................................
*/
SQLITE_PRIVATE void sqlite3DebugPrintf(const char *zFormat, ...){
  va_list ap;
  StrAccum acc;
  char zBuf[500];
  sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
  va_start(ap,zFormat);
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  va_end(ap);
  sqlite3StrAccumFinish(&acc);
  fprintf(stdout,"%s", zBuf);
  fflush(stdout);
}
#endif


/*
** variable-argument wrapper around sqlite3VXPrintf().  The bFlags argument
** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.
*/
SQLITE_PRIVATE void sqlite3XPrintf(StrAccum *p, u32 bFlags, const char *zFormat, ...){
  va_list ap;
  va_start(ap,zFormat);
  sqlite3VXPrintf(p, bFlags, zFormat, ap);
  va_end(ap);
}

/************** End of printf.c **********************************************/
/************** Begin file treeview.c ****************************************/
/*
** 2015-06-08
................................................................................
  if( p ){
    for(i=0; i<p->iLevel && i<sizeof(p->bLine)-1; i++){
      sqlite3StrAccumAppend(&acc, p->bLine[i] ? "|   " : "    ", 4);
    }
    sqlite3StrAccumAppend(&acc, p->bLine[i] ? "|-- " : "'-- ", 4);
  }
  va_start(ap, zFormat);
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  va_end(ap);
  if( zBuf[acc.nChar-1]!='\n' ) sqlite3StrAccumAppend(&acc, "\n", 1);
  sqlite3StrAccumFinish(&acc);
  fprintf(stdout,"%s", zBuf);
  fflush(stdout);
}

................................................................................
  if( pWith->nCte>0 ){
    pView = sqlite3TreeViewPush(pView, 1);
    for(i=0; i<pWith->nCte; i++){
      StrAccum x;
      char zLine[1000];
      const struct Cte *pCte = &pWith->a[i];
      sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);
      sqlite3XPrintf(&x, 0, "%s", pCte->zName);
      if( pCte->pCols && pCte->pCols->nExpr>0 ){
        char cSep = '(';
        int j;
        for(j=0; j<pCte->pCols->nExpr; j++){
          sqlite3XPrintf(&x, 0, "%c%s", cSep, pCte->pCols->a[j].zName);
          cSep = ',';
        }
        sqlite3XPrintf(&x, 0, ")");
      }
      sqlite3XPrintf(&x, 0, " AS");
      sqlite3StrAccumFinish(&x);
      sqlite3TreeViewItem(pView, zLine, i<pWith->nCte-1);
      sqlite3TreeViewSelect(pView, pCte->pSelect, 0);
      sqlite3TreeViewPop(pView);
    }
    sqlite3TreeViewPop(pView);
  }
................................................................................
      pView = sqlite3TreeViewPush(pView, (n--)>0);
      sqlite3TreeViewLine(pView, "FROM");
      for(i=0; i<p->pSrc->nSrc; i++){
        struct SrcList_item *pItem = &p->pSrc->a[i];
        StrAccum x;
        char zLine[100];
        sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);
        sqlite3XPrintf(&x, 0, "{%d,*}", pItem->iCursor);
        if( pItem->zDatabase ){
          sqlite3XPrintf(&x, 0, " %s.%s", pItem->zDatabase, pItem->zName);
        }else if( pItem->zName ){
          sqlite3XPrintf(&x, 0, " %s", pItem->zName);
        }
        if( pItem->pTab ){
          sqlite3XPrintf(&x, 0, " tabname=%Q", pItem->pTab->zName);
        }
        if( pItem->zAlias ){
          sqlite3XPrintf(&x, 0, " (AS %s)", pItem->zAlias);
        }
        if( pItem->fg.jointype & JT_LEFT ){
          sqlite3XPrintf(&x, 0, " LEFT-JOIN");
        }
        sqlite3StrAccumFinish(&x);
        sqlite3TreeViewItem(pView, zLine, i<p->pSrc->nSrc-1); 
        if( pItem->pSelect ){
          sqlite3TreeViewSelect(pView, pItem->pSelect, 0);
        }
        if( pItem->fg.isTabFunc ){
................................................................................
    pMem->n = (int)(z - zOut);
  }
  *z = 0;
  assert( (pMem->n+(desiredEnc==SQLITE_UTF8?1:2))<=len );

  c = pMem->flags;
  sqlite3VdbeMemRelease(pMem);
  pMem->flags = MEM_Str|MEM_Term|(c&MEM_AffMask);
  pMem->enc = desiredEnc;
  pMem->z = (char*)zOut;
  pMem->zMalloc = pMem->z;
  pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->z);

translate_out:
#if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
................................................................................
    }else{
      z[j++] = z[i];
    }
  }
  z[j] = 0;
  return j;
}









/* Convenient short-hand */
#define UpperToLower sqlite3UpperToLower

/*
** Some systems have stricmp().  Others have strcasecmp().  Because
** there is no consistency, we will define our own.
................................................................................
** binary value has been obtained from malloc and must be freed by
** the calling routine.
*/
SQLITE_PRIVATE void *sqlite3HexToBlob(sqlite3 *db, const char *z, int n){
  char *zBlob;
  int i;

  zBlob = (char *)sqlite3DbMallocRaw(db, n/2 + 1);
  n--;
  if( zBlob ){
    for(i=0; i<n; i+=2){
      zBlob[i/2] = (sqlite3HexToInt(z[i])<<4) | sqlite3HexToInt(z[i+1]);
    }
    zBlob[i/2] = 0;
  }
................................................................................
 || defined(SQLITE_DEBUG)
#if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS) || defined(SQLITE_DEBUG)
# define OpHelp(X) "\0" X
#else
# define OpHelp(X)
#endif
SQLITE_PRIVATE const char *sqlite3OpcodeName(int i){
 static const char *const azName[] = { "?",
    /*   1 */ "Savepoint"        OpHelp(""),
    /*   2 */ "AutoCommit"       OpHelp(""),
    /*   3 */ "Transaction"      OpHelp(""),
    /*   4 */ "SorterNext"       OpHelp(""),
    /*   5 */ "PrevIfOpen"       OpHelp(""),
    /*   6 */ "NextIfOpen"       OpHelp(""),
    /*   7 */ "Prev"             OpHelp(""),
    /*   8 */ "Next"             OpHelp(""),
    /*   9 */ "Checkpoint"       OpHelp(""),
    /*  10 */ "JournalMode"      OpHelp(""),
    /*  11 */ "Vacuum"           OpHelp(""),
    /*  12 */ "VFilter"          OpHelp("iplan=r[P3] zplan='P4'"),
    /*  13 */ "VUpdate"          OpHelp("data=r[P3@P2]"),
    /*  14 */ "Goto"             OpHelp(""),
    /*  15 */ "Gosub"            OpHelp(""),
    /*  16 */ "Return"           OpHelp(""),
    /*  17 */ "InitCoroutine"    OpHelp(""),
    /*  18 */ "EndCoroutine"     OpHelp(""),

    /*  19 */ "Not"              OpHelp("r[P2]= !r[P1]"),
    /*  20 */ "Yield"            OpHelp(""),
    /*  21 */ "HaltIfNull"       OpHelp("if r[P3]=null halt"),
    /*  22 */ "Halt"             OpHelp(""),
    /*  23 */ "Integer"          OpHelp("r[P2]=P1"),
    /*  24 */ "Int64"            OpHelp("r[P2]=P4"),
    /*  25 */ "String"           OpHelp("r[P2]='P4' (len=P1)"),
    /*  26 */ "Null"             OpHelp("r[P2..P3]=NULL"),
    /*  27 */ "SoftNull"         OpHelp("r[P1]=NULL"),
    /*  28 */ "Blob"             OpHelp("r[P2]=P4 (len=P1)"),
    /*  29 */ "Variable"         OpHelp("r[P2]=parameter(P1,P4)"),
    /*  30 */ "Move"             OpHelp("r[P2@P3]=r[P1@P3]"),
    /*  31 */ "Copy"             OpHelp("r[P2@P3+1]=r[P1@P3+1]"),
    /*  32 */ "SCopy"            OpHelp("r[P2]=r[P1]"),
    /*  33 */ "IntCopy"          OpHelp("r[P2]=r[P1]"),
    /*  34 */ "ResultRow"        OpHelp("output=r[P1@P2]"),
    /*  35 */ "CollSeq"          OpHelp(""),
    /*  36 */ "Function0"        OpHelp("r[P3]=func(r[P2@P5])"),
    /*  37 */ "Function"         OpHelp("r[P3]=func(r[P2@P5])"),
    /*  38 */ "AddImm"           OpHelp("r[P1]=r[P1]+P2"),
    /*  39 */ "MustBeInt"        OpHelp(""),
    /*  40 */ "RealAffinity"     OpHelp(""),
    /*  41 */ "Cast"             OpHelp("affinity(r[P1])"),
    /*  42 */ "Permutation"      OpHelp(""),
    /*  43 */ "Compare"          OpHelp("r[P1@P3] <-> r[P2@P3]"),
    /*  44 */ "Jump"             OpHelp(""),
    /*  45 */ "Once"             OpHelp(""),
    /*  46 */ "If"               OpHelp(""),
    /*  47 */ "IfNot"            OpHelp(""),
    /*  48 */ "Column"           OpHelp("r[P3]=PX"),
    /*  49 */ "Affinity"         OpHelp("affinity(r[P1@P2])"),
    /*  50 */ "MakeRecord"       OpHelp("r[P3]=mkrec(r[P1@P2])"),
    /*  51 */ "Count"            OpHelp("r[P2]=count()"),
    /*  52 */ "ReadCookie"       OpHelp(""),
    /*  53 */ "SetCookie"        OpHelp(""),
    /*  54 */ "ReopenIdx"        OpHelp("root=P2 iDb=P3"),
    /*  55 */ "OpenRead"         OpHelp("root=P2 iDb=P3"),
    /*  56 */ "OpenWrite"        OpHelp("root=P2 iDb=P3"),
    /*  57 */ "OpenAutoindex"    OpHelp("nColumn=P2"),
    /*  58 */ "OpenEphemeral"    OpHelp("nColumn=P2"),
    /*  59 */ "SorterOpen"       OpHelp(""),
    /*  60 */ "SequenceTest"     OpHelp("if( cursor[P1].ctr++ ) pc = P2"),
    /*  61 */ "OpenPseudo"       OpHelp("P3 columns in r[P2]"),
    /*  62 */ "Close"            OpHelp(""),
    /*  63 */ "ColumnsUsed"      OpHelp(""),
    /*  64 */ "SeekLT"           OpHelp("key=r[P3@P4]"),
    /*  65 */ "SeekLE"           OpHelp("key=r[P3@P4]"),
    /*  66 */ "SeekGE"           OpHelp("key=r[P3@P4]"),
    /*  67 */ "SeekGT"           OpHelp("key=r[P3@P4]"),
    /*  68 */ "Seek"             OpHelp("intkey=r[P2]"),
    /*  69 */ "NoConflict"       OpHelp("key=r[P3@P4]"),
    /*  70 */ "NotFound"         OpHelp("key=r[P3@P4]"),


    /*  71 */ "Or"               OpHelp("r[P3]=(r[P1] || r[P2])"),
    /*  72 */ "And"              OpHelp("r[P3]=(r[P1] && r[P2])"),
    /*  73 */ "Found"            OpHelp("key=r[P3@P4]"),
    /*  74 */ "NotExists"        OpHelp("intkey=r[P3]"),
    /*  75 */ "Sequence"         OpHelp("r[P2]=cursor[P1].ctr++"),


    /*  76 */ "IsNull"           OpHelp("if r[P1]==NULL goto P2"),
    /*  77 */ "NotNull"          OpHelp("if r[P1]!=NULL goto P2"),
    /*  78 */ "Ne"               OpHelp("if r[P1]!=r[P3] goto P2"),
    /*  79 */ "Eq"               OpHelp("if r[P1]==r[P3] goto P2"),
    /*  80 */ "Gt"               OpHelp("if r[P1]>r[P3] goto P2"),
    /*  81 */ "Le"               OpHelp("if r[P1]<=r[P3] goto P2"),
    /*  82 */ "Lt"               OpHelp("if r[P1]<r[P3] goto P2"),
    /*  83 */ "Ge"               OpHelp("if r[P1]>=r[P3] goto P2"),
    /*  84 */ "NewRowid"         OpHelp("r[P2]=rowid"),
    /*  85 */ "BitAnd"           OpHelp("r[P3]=r[P1]&r[P2]"),
    /*  86 */ "BitOr"            OpHelp("r[P3]=r[P1]|r[P2]"),
    /*  87 */ "ShiftLeft"        OpHelp("r[P3]=r[P2]<<r[P1]"),
    /*  88 */ "ShiftRight"       OpHelp("r[P3]=r[P2]>>r[P1]"),
    /*  89 */ "Add"              OpHelp("r[P3]=r[P1]+r[P2]"),
    /*  90 */ "Subtract"         OpHelp("r[P3]=r[P2]-r[P1]"),
    /*  91 */ "Multiply"         OpHelp("r[P3]=r[P1]*r[P2]"),
    /*  92 */ "Divide"           OpHelp("r[P3]=r[P2]/r[P1]"),
    /*  93 */ "Remainder"        OpHelp("r[P3]=r[P2]%r[P1]"),
    /*  94 */ "Concat"           OpHelp("r[P3]=r[P2]+r[P1]"),
    /*  95 */ "Insert"           OpHelp("intkey=r[P3] data=r[P2]"),
    /*  96 */ "BitNot"           OpHelp("r[P1]= ~r[P1]"),
    /*  97 */ "String8"          OpHelp("r[P2]='P4'"),
    /*  98 */ "InsertInt"        OpHelp("intkey=P3 data=r[P2]"),
    /*  99 */ "Delete"           OpHelp(""),
    /* 100 */ "ResetCount"       OpHelp(""),
    /* 101 */ "SorterCompare"    OpHelp("if key(P1)!=trim(r[P3],P4) goto P2"),
    /* 102 */ "SorterData"       OpHelp("r[P2]=data"),
    /* 103 */ "RowKey"           OpHelp("r[P2]=key"),
    /* 104 */ "RowData"          OpHelp("r[P2]=data"),
    /* 105 */ "Rowid"            OpHelp("r[P2]=rowid"),
    /* 106 */ "NullRow"          OpHelp(""),
    /* 107 */ "Last"             OpHelp(""),
    /* 108 */ "SorterSort"       OpHelp(""),
    /* 109 */ "Sort"             OpHelp(""),
    /* 110 */ "Rewind"           OpHelp(""),
    /* 111 */ "SorterInsert"     OpHelp(""),
    /* 112 */ "IdxInsert"        OpHelp("key=r[P2]"),
    /* 113 */ "IdxDelete"        OpHelp("key=r[P2@P3]"),

    /* 114 */ "IdxRowid"         OpHelp("r[P2]=rowid"),
    /* 115 */ "IdxLE"            OpHelp("key=r[P3@P4]"),
    /* 116 */ "IdxGT"            OpHelp("key=r[P3@P4]"),
    /* 117 */ "IdxLT"            OpHelp("key=r[P3@P4]"),
    /* 118 */ "IdxGE"            OpHelp("key=r[P3@P4]"),
    /* 119 */ "Destroy"          OpHelp(""),
    /* 120 */ "Clear"            OpHelp(""),
    /* 121 */ "ResetSorter"      OpHelp(""),
    /* 122 */ "CreateIndex"      OpHelp("r[P2]=root iDb=P1"),
    /* 123 */ "CreateTable"      OpHelp("r[P2]=root iDb=P1"),
    /* 124 */ "ParseSchema"      OpHelp(""),
    /* 125 */ "LoadAnalysis"     OpHelp(""),
    /* 126 */ "DropTable"        OpHelp(""),
    /* 127 */ "DropIndex"        OpHelp(""),
    /* 128 */ "DropTrigger"      OpHelp(""),
    /* 129 */ "IntegrityCk"      OpHelp(""),
    /* 130 */ "RowSetAdd"        OpHelp("rowset(P1)=r[P2]"),
    /* 131 */ "RowSetRead"       OpHelp("r[P3]=rowset(P1)"),
    /* 132 */ "RowSetTest"       OpHelp("if r[P3] in rowset(P1) goto P2"),

    /* 133 */ "Real"             OpHelp("r[P2]=P4"),
    /* 134 */ "Program"          OpHelp(""),
    /* 135 */ "Param"            OpHelp(""),
    /* 136 */ "FkCounter"        OpHelp("fkctr[P1]+=P2"),
    /* 137 */ "FkIfZero"         OpHelp("if fkctr[P1]==0 goto P2"),
    /* 138 */ "MemMax"           OpHelp("r[P1]=max(r[P1],r[P2])"),
    /* 139 */ "IfPos"            OpHelp("if r[P1]>0 then r[P1]-=P3, goto P2"),
    /* 140 */ "SetIfNotPos"      OpHelp("if r[P1]<=0 then r[P2]=P3"),

    /* 141 */ "IfNotZero"        OpHelp("if r[P1]!=0 then r[P1]-=P3, goto P2"),
    /* 142 */ "DecrJumpZero"     OpHelp("if (--r[P1])==0 goto P2"),
    /* 143 */ "JumpZeroIncr"     OpHelp("if (r[P1]++)==0 ) goto P2"),
    /* 144 */ "AggStep0"         OpHelp("accum=r[P3] step(r[P2@P5])"),
    /* 145 */ "AggStep"          OpHelp("accum=r[P3] step(r[P2@P5])"),
    /* 146 */ "AggFinal"         OpHelp("accum=r[P1] N=P2"),
    /* 147 */ "IncrVacuum"       OpHelp(""),
    /* 148 */ "Expire"           OpHelp(""),
    /* 149 */ "TableLock"        OpHelp("iDb=P1 root=P2 write=P3"),
    /* 150 */ "VBegin"           OpHelp(""),
    /* 151 */ "VCreate"          OpHelp(""),
    /* 152 */ "VDestroy"         OpHelp(""),
    /* 153 */ "VOpen"            OpHelp(""),
    /* 154 */ "VColumn"          OpHelp("r[P3]=vcolumn(P2)"),
    /* 155 */ "VNext"            OpHelp(""),
    /* 156 */ "VRename"          OpHelp(""),
    /* 157 */ "Pagecount"        OpHelp(""),
    /* 158 */ "MaxPgcnt"         OpHelp(""),
    /* 159 */ "Init"             OpHelp("Start at P2"),
    /* 160 */ "CursorHint"       OpHelp(""),
    /* 161 */ "Noop"             OpHelp(""),
    /* 162 */ "Explain"          OpHelp(""),
  };
  return azName[i];
}
#endif

/************** End of opcodes.c *********************************************/
/************** Begin file os_unix.c *****************************************/
................................................................................
#endif

/*
** Maximum supported path-length.
*/
#define MAX_PATHNAME 512






/* Always cast the getpid() return type for compatibility with
** kernel modules in VxWorks. */
#define osGetpid(X) (pid_t)getpid()

/*
** Only set the lastErrno if the error code is a real error and not 
** a normal expected return code of SQLITE_BUSY or SQLITE_OK
................................................................................

/*
** Macros for performance tracing.  Normally turned off.  Only works
** on i486 hardware.
*/
#ifdef SQLITE_PERFORMANCE_TRACE

/* 
** hwtime.h contains inline assembler code for implementing 
** high-performance timing routines.
*/
/************** Include hwtime.h in the middle of os_common.h ****************/
/************** Begin file hwtime.h ******************************************/
/*
** 2008 May 27
**
................................................................................
#endif

/*
** If we compile with the SQLITE_TEST macro set, then the following block
** of code will give us the ability to simulate a disk I/O error.  This
** is used for testing the I/O recovery logic.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
SQLITE_API int sqlite3_diskfull_pending = 0;
SQLITE_API int sqlite3_diskfull = 0;
#define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
#define SimulateIOError(CODE)  \
  if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
       || sqlite3_io_error_pending-- == 1 )  \
              { local_ioerr(); CODE; }
static void local_ioerr(){
  IOTRACE(("IOERR\n"));
................................................................................
       sqlite3_diskfull_pending--; \
     } \
   }
#else
#define SimulateIOErrorBenign(X)
#define SimulateIOError(A)
#define SimulateDiskfullError(A)
#endif

/*
** When testing, keep a count of the number of open files.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_open_file_count = 0;
#define OpenCounter(X)  sqlite3_open_file_count+=(X)
#else
#define OpenCounter(X)
#endif

#endif /* !defined(_OS_COMMON_H_) */

/************** End of os_common.h *******************************************/
/************** Continuing where we left off in os_unix.c ********************/

/*
................................................................................

  { "mkdir",        (sqlite3_syscall_ptr)mkdir,           0 },
#define osMkdir     ((int(*)(const char*,mode_t))aSyscall[18].pCurrent)

  { "rmdir",        (sqlite3_syscall_ptr)rmdir,           0 },
#define osRmdir     ((int(*)(const char*))aSyscall[19].pCurrent)


  { "fchown",       (sqlite3_syscall_ptr)fchown,          0 },



#define osFchown    ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)

  { "geteuid",      (sqlite3_syscall_ptr)geteuid,         0 },
#define osGeteuid   ((uid_t(*)(void))aSyscall[21].pCurrent)

#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
  { "mmap",       (sqlite3_syscall_ptr)mmap,     0 },



#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[22].pCurrent)


  { "munmap",       (sqlite3_syscall_ptr)munmap,          0 },



#define osMunmap ((void*(*)(void*,size_t))aSyscall[23].pCurrent)

#if HAVE_MREMAP

  { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },
#else
  { "mremap",       (sqlite3_syscall_ptr)0,               0 },
#endif
#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[24].pCurrent)


  { "getpagesize",  (sqlite3_syscall_ptr)unixGetpagesize, 0 },



#define osGetpagesize ((int(*)(void))aSyscall[25].pCurrent)


  { "readlink",     (sqlite3_syscall_ptr)readlink,        0 },



#define osReadlink ((ssize_t(*)(const char*,char*,size_t))aSyscall[26].pCurrent)





#endif


}; /* End of the overrideable system calls */


/*
** On some systems, calls to fchown() will trigger a message in a security
** log if they come from non-root processes.  So avoid calling fchown() if
** we are not running as root.
*/
static int robustFchown(int fd, uid_t uid, gid_t gid){
#if OS_VXWORKS
  return 0;
#else
  return osGeteuid() ? 0 : osFchown(fd,uid,gid);
#endif
}

/*
** This is the xSetSystemCall() method of sqlite3_vfs for all of the
** "unix" VFSes.  Return SQLITE_OK opon successfully updating the
** system call pointer, or SQLITE_NOTFOUND if there is no configurable
................................................................................
    return rc;
  }
#ifndef SQLITE_DISABLE_DIRSYNC
  if( (dirSync & 1)!=0 ){
    int fd;
    rc = osOpenDirectory(zPath, &fd);
    if( rc==SQLITE_OK ){
#if OS_VXWORKS
      if( fsync(fd)==-1 )
#else
      if( fsync(fd) )
#endif
      {
        rc = unixLogError(SQLITE_IOERR_DIR_FSYNC, "fsync", zPath);
      }
      robust_close(0, fd, __LINE__);
    }else{
      assert( rc==SQLITE_CANTOPEN );
      rc = SQLITE_OK;
    }
................................................................................
    *pResOut = (0==osStat(zPath, &buf) && buf.st_size>0);
  }else{
    *pResOut = osAccess(zPath, W_OK|R_OK)==0;
  }
  return SQLITE_OK;
}




























/*
** Turn a relative pathname into a full pathname. The relative path
** is stored as a nul-terminated string in the buffer pointed to by
** zPath. 
**
** zOut points to a buffer of at least sqlite3_vfs.mxPathname bytes 
................................................................................
*/
static int unixFullPathname(
  sqlite3_vfs *pVfs,            /* Pointer to vfs object */
  const char *zPath,            /* Possibly relative input path */
  int nOut,                     /* Size of output buffer in bytes */
  char *zOut                    /* Output buffer */
){




  int nByte;







  /* It's odd to simulate an io-error here, but really this is just
  ** using the io-error infrastructure to test that SQLite handles this
  ** function failing. This function could fail if, for example, the
  ** current working directory has been unlinked.
  */
  SimulateIOError( return SQLITE_ERROR );

  assert( pVfs->mxPathname==MAX_PATHNAME );
  UNUSED_PARAMETER(pVfs);


  /* Attempt to resolve the path as if it were a symbolic link. If it is
  ** a symbolic link, the resolved path is stored in buffer zOut[]. Or, if
  ** the identified file is not a symbolic link or does not exist, then
  ** zPath is copied directly into zOut. Either way, nByte is left set to
  ** the size of the string copied into zOut[] in bytes.  */
  nByte = osReadlink(zPath, zOut, nOut-1);
  if( nByte<0 ){





    if( errno!=EINVAL && errno!=ENOENT ){
      return unixLogError(SQLITE_CANTOPEN_BKPT, "readlink", zPath);
    }
    sqlite3_snprintf(nOut, zOut, "%s", zPath);
    nByte = sqlite3Strlen30(zOut);
  }else{
    zOut[nByte] = '\0';

  }

  /* If buffer zOut[] now contains an absolute path there is nothing more
  ** to do. If it contains a relative path, do the following:
  **
  **   * move the relative path string so that it is at the end of th
  **     zOut[] buffer.
  **   * Call getcwd() to read the path of the current working directory 
  **     into the start of the zOut[] buffer.
  **   * Append a '/' character to the cwd string and move the 
  **     relative path back within the buffer so that it immediately 
  **     follows the '/'.
  **
  ** This code is written so that if the combination of the CWD and relative
  ** path are larger than the allocated size of zOut[] the CWD is silently



  ** truncated to make it fit. This is Ok, as SQLite refuses to open any
  ** file for which this function returns a full path larger than (nOut-8)
  ** bytes in size.  */
  testcase( nByte==nOut-5 );
  testcase( nByte==nOut-4 );
  if( zOut[0]!='/' && nByte<nOut-4 ){
    int nCwd;
    int nRem = nOut-nByte-1;
    memmove(&zOut[nRem], zOut, nByte+1);
    zOut[nRem-1] = '\0';
    if( osGetcwd(zOut, nRem-1)==0 ){
      return unixLogError(SQLITE_CANTOPEN_BKPT, "getcwd", zPath);




    }
    nCwd = sqlite3Strlen30(zOut);
    assert( nCwd<=nRem-1 );
    zOut[nCwd] = '/';

    memmove(&zOut[nCwd+1], &zOut[nRem], nByte+1);
  }














  return SQLITE_OK;

}


#ifndef SQLITE_OMIT_LOAD_EXTENSION
/*
** Interfaces for opening a shared library, finding entry points
** within the shared library, and closing the shared library.
................................................................................
    *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch;
  }
#endif
  UNUSED_PARAMETER(NotUsed);
  return rc;
}

#if 0 /* Not used */
/*
** Find the current time (in Universal Coordinated Time).  Write the
** current time and date as a Julian Day number into *prNow and
** return 0.  Return 1 if the time and date cannot be found.
*/
static int unixCurrentTime(sqlite3_vfs *NotUsed, double *prNow){
  sqlite3_int64 i = 0;
................................................................................
  *prNow = i/86400000.0;
  return rc;
}
#else
# define unixCurrentTime 0
#endif

#if 0  /* Not used */
/*
** We added the xGetLastError() method with the intention of providing
** better low-level error messages when operating-system problems come up
** during SQLite operation.  But so far, none of that has been implemented
** in the core.  So this routine is never called.  For now, it is merely
** a place-holder.
*/
................................................................................
                  MAXPATHLEN);
        }else{
          strlcpy(&writeBuffer[PROXY_PATHINDEX], tempLockPath, MAXPATHLEN);
        }
        writeSize = PROXY_PATHINDEX + strlen(&writeBuffer[PROXY_PATHINDEX]);
        robust_ftruncate(conchFile->h, writeSize);
        rc = unixWrite((sqlite3_file *)conchFile, writeBuffer, writeSize, 0);
        fsync(conchFile->h);
        /* If we created a new conch file (not just updated the contents of a 
         ** valid conch file), try to match the permissions of the database 
         */
        if( rc==SQLITE_OK && createConch ){
          struct stat buf;
          int err = osFstat(pFile->h, &buf);
          if( err==0 ){
................................................................................
    UNIXVFS("unix-proxy",    proxyIoFinder ),
#endif
  };
  unsigned int i;          /* Loop counter */

  /* Double-check that the aSyscall[] array has been constructed
  ** correctly.  See ticket [bb3a86e890c8e96ab] */
  assert( ArraySize(aSyscall)==27 );

  /* Register all VFSes defined in the aVfs[] array */
  for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){
    sqlite3_vfs_register(&aVfs[i], i==0);
  }
  return SQLITE_OK; 
}
................................................................................

/*
** Macros for performance tracing.  Normally turned off.  Only works
** on i486 hardware.
*/
#ifdef SQLITE_PERFORMANCE_TRACE

/* 
** hwtime.h contains inline assembler code for implementing 
** high-performance timing routines.
*/
/************** Include hwtime.h in the middle of os_common.h ****************/
/************** Begin file hwtime.h ******************************************/
/*
** 2008 May 27
**
................................................................................
#endif

/*
** If we compile with the SQLITE_TEST macro set, then the following block
** of code will give us the ability to simulate a disk I/O error.  This
** is used for testing the I/O recovery logic.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
SQLITE_API int sqlite3_diskfull_pending = 0;
SQLITE_API int sqlite3_diskfull = 0;
#define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
#define SimulateIOError(CODE)  \
  if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
       || sqlite3_io_error_pending-- == 1 )  \
              { local_ioerr(); CODE; }
static void local_ioerr(){
  IOTRACE(("IOERR\n"));
................................................................................
       sqlite3_diskfull_pending--; \
     } \
   }
#else
#define SimulateIOErrorBenign(X)
#define SimulateIOError(A)
#define SimulateDiskfullError(A)
#endif

/*
** When testing, keep a count of the number of open files.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_open_file_count = 0;
#define OpenCounter(X)  sqlite3_open_file_count+=(X)
#else
#define OpenCounter(X)
#endif

#endif /* !defined(_OS_COMMON_H_) */

/************** End of os_common.h *******************************************/
/************** Continuing where we left off in os_win.c *********************/

/*
................................................................................
#  define NTDDI_WIN8                        0x06020000
#endif

#ifndef NTDDI_WINBLUE
#  define NTDDI_WINBLUE                     0x06030000
#endif





/*
** Check to see if the GetVersionEx[AW] functions are deprecated on the
** target system.  GetVersionEx was first deprecated in Win8.1.
*/
#ifndef SQLITE_WIN32_GETVERSIONEX
#  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINBLUE
#    define SQLITE_WIN32_GETVERSIONEX   0   /* GetVersionEx() is deprecated */
#  else
#    define SQLITE_WIN32_GETVERSIONEX   1   /* GetVersionEx() is current */
#  endif
#endif














/*
** This constant should already be defined (in the "WinDef.h" SDK file).
*/
#ifndef MAX_PATH
#  define MAX_PATH                      (260)
#endif

................................................................................
#else
  { "CreateFileW",             (SYSCALL)0,                       0 },
#endif

#define osCreateFileW ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD, \
        LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[5].pCurrent)

#if (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \
        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))

  { "CreateFileMappingA",      (SYSCALL)CreateFileMappingA,      0 },
#else
  { "CreateFileMappingA",      (SYSCALL)0,                       0 },
#endif

#define osCreateFileMappingA ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
        DWORD,DWORD,DWORD,LPCSTR))aSyscall[6].pCurrent)
................................................................................
  { "GetTickCount",            (SYSCALL)GetTickCount,            0 },
#else
  { "GetTickCount",            (SYSCALL)0,                       0 },
#endif

#define osGetTickCount ((DWORD(WINAPI*)(VOID))aSyscall[33].pCurrent)

#if defined(SQLITE_WIN32_HAS_ANSI) && defined(SQLITE_WIN32_GETVERSIONEX) && \
        SQLITE_WIN32_GETVERSIONEX
  { "GetVersionExA",           (SYSCALL)GetVersionExA,           0 },
#else
  { "GetVersionExA",           (SYSCALL)0,                       0 },
#endif

#define osGetVersionExA ((BOOL(WINAPI*)( \
        LPOSVERSIONINFOA))aSyscall[34].pCurrent)

#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
        defined(SQLITE_WIN32_GETVERSIONEX) && SQLITE_WIN32_GETVERSIONEX
  { "GetVersionExW",           (SYSCALL)GetVersionExW,           0 },
#else
  { "GetVersionExW",           (SYSCALL)0,                       0 },
#endif

#define osGetVersionExW ((BOOL(WINAPI*)( \
        LPOSVERSIONINFOW))aSyscall[35].pCurrent)
................................................................................
** the LockFileEx() API.  But we can still statically link against that
** API as long as we don't call it when running Win95/98/ME.  A call to
** this routine is used to determine if the host is Win95/98/ME or
** WinNT/2K/XP so that we will know whether or not we can safely call
** the LockFileEx() API.
*/

#if !defined(SQLITE_WIN32_GETVERSIONEX) || !SQLITE_WIN32_GETVERSIONEX
# define osIsNT()  (1)
#elif SQLITE_OS_WINCE || SQLITE_OS_WINRT || !defined(SQLITE_WIN32_HAS_ANSI)
# define osIsNT()  (1)
#elif !defined(SQLITE_WIN32_HAS_WIDE)
# define osIsNT()  (0)
#else
# define osIsNT()  ((sqlite3_os_type==2) || sqlite3_win32_is_nt())
................................................................................
SQLITE_API int SQLITE_STDCALL sqlite3_win32_is_nt(void){
#if SQLITE_OS_WINRT
  /*
  ** NOTE: The WinRT sub-platform is always assumed to be based on the NT
  **       kernel.
  */
  return 1;
#elif defined(SQLITE_WIN32_GETVERSIONEX) && SQLITE_WIN32_GETVERSIONEX
  if( osInterlockedCompareExchange(&sqlite3_os_type, 0, 0)==0 ){
#if defined(SQLITE_WIN32_HAS_ANSI)
    OSVERSIONINFOA sInfo;
    sInfo.dwOSVersionInfoSize = sizeof(sInfo);
    osGetVersionExA(&sInfo);
    osInterlockedCompareExchange(&sqlite3_os_type,
        (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);
................................................................................
      hMap = osCreateFileMappingFromApp(pShmNode->hFile.h,
          NULL, PAGE_READWRITE, nByte, NULL
      );
#elif defined(SQLITE_WIN32_HAS_WIDE)
      hMap = osCreateFileMappingW(pShmNode->hFile.h,
          NULL, PAGE_READWRITE, 0, nByte, NULL
      );
#elif defined(SQLITE_WIN32_HAS_ANSI)
      hMap = osCreateFileMappingA(pShmNode->hFile.h,
          NULL, PAGE_READWRITE, 0, nByte, NULL
      );
#endif
      OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",
               osGetCurrentProcessId(), pShmNode->nRegion, nByte,
               hMap ? "ok" : "failed"));
................................................................................
#endif
#if SQLITE_OS_WINRT
    pFd->hMap = osCreateFileMappingFromApp(pFd->h, NULL, protect, nMap, NULL);
#elif defined(SQLITE_WIN32_HAS_WIDE)
    pFd->hMap = osCreateFileMappingW(pFd->h, NULL, protect,
                                (DWORD)((nMap>>32) & 0xffffffff),
                                (DWORD)(nMap & 0xffffffff), NULL);
#elif defined(SQLITE_WIN32_HAS_ANSI)
    pFd->hMap = osCreateFileMappingA(pFd->h, NULL, protect,
                                (DWORD)((nMap>>32) & 0xffffffff),
                                (DWORD)(nMap & 0xffffffff), NULL);
#endif
    if( pFd->hMap==NULL ){
      pFd->lastErrno = osGetLastError();
      rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
................................................................................
** In an OOM situation, the RowSet.db->mallocFailed flag is set and this
** routine returns NULL.
*/
static struct RowSetEntry *rowSetEntryAlloc(RowSet *p){
  assert( p!=0 );
  if( p->nFresh==0 ){
    struct RowSetChunk *pNew;
    pNew = sqlite3DbMallocRaw(p->db, sizeof(*pNew));
    if( pNew==0 ){
      return 0;
    }
    pNew->pNextChunk = p->pChunk;
    p->pChunk = pNew;
    p->pFresh = pNew->aEntry;
    p->nFresh = ROWSET_ENTRY_PER_CHUNK;
................................................................................
/*
** The maximum allowed sector size. 64KiB. If the xSectorsize() method 
** returns a value larger than this, then MAX_SECTOR_SIZE is used instead.
** This could conceivably cause corruption following a power failure on
** such a system. This is currently an undocumented limit.
*/
#define MAX_SECTOR_SIZE 0x10000















/*
** An instance of the following structure is allocated for each active
** savepoint and statement transaction in the system. All such structures
** are stored in the Pager.aSavepoint[] array, which is allocated and
** resized using sqlite3Realloc().
**
................................................................................
struct Pager {
  sqlite3_vfs *pVfs;          /* OS functions to use for IO */
  u8 exclusiveMode;           /* Boolean. True if locking_mode==EXCLUSIVE */
  u8 journalMode;             /* One of the PAGER_JOURNALMODE_* values */
  u8 useJournal;              /* Use a rollback journal on this file */
  u8 noSync;                  /* Do not sync the journal if true */
  u8 fullSync;                /* Do extra syncs of the journal for robustness */

  u8 ckptSyncFlags;           /* SYNC_NORMAL or SYNC_FULL for checkpoint */
  u8 walSyncFlags;            /* SYNC_NORMAL or SYNC_FULL for wal writes */
  u8 syncFlags;               /* SYNC_NORMAL or SYNC_FULL otherwise */
  u8 tempFile;                /* zFilename is a temporary or immutable file */
  u8 noLock;                  /* Do not lock (except in WAL mode) */
  u8 readOnly;                /* True for a read-only database */
  u8 memDb;                   /* True to inhibit all file I/O */
................................................................................
      int bDelete = (!pPager->tempFile && sqlite3JournalExists(pPager->jfd));
      assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE 
           || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 
           || pPager->journalMode==PAGER_JOURNALMODE_WAL 
      );
      sqlite3OsClose(pPager->jfd);
      if( bDelete ){
        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }
    }
  }

#ifdef SQLITE_CHECK_PAGES
  sqlite3PcacheIterateDirty(pPager->pPCache, pager_set_pagehash);
  if( pPager->dbSize==0 && sqlite3PcacheRefCount(pPager->pPCache)>0 ){
................................................................................
*/
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
SQLITE_PRIVATE void sqlite3PagerSetFlags(
  Pager *pPager,        /* The pager to set safety level for */
  unsigned pgFlags      /* Various flags */
){
  unsigned level = pgFlags & PAGER_SYNCHRONOUS_MASK;
  assert( level>=1 && level<=3 );
  pPager->noSync =  (level==1 || pPager->tempFile) ?1:0;
  pPager->fullSync = (level==3 && !pPager->tempFile) ?1:0;






  if( pPager->noSync ){
    pPager->syncFlags = 0;
    pPager->ckptSyncFlags = 0;
  }else if( pgFlags & PAGER_FULLFSYNC ){
    pPager->syncFlags = SQLITE_SYNC_FULL;
    pPager->ckptSyncFlags = SQLITE_SYNC_FULL;
  }else if( pgFlags & PAGER_CKPT_FULLFSYNC ){
................................................................................
  pPager->changeCountDone = pPager->tempFile;
  pPager->memDb = (u8)memDb;
  pPager->readOnly = (u8)readOnly;
  assert( useJournal || pPager->tempFile );
  pPager->noSync = pPager->tempFile;
  if( pPager->noSync ){
    assert( pPager->fullSync==0 );

    assert( pPager->syncFlags==0 );
    assert( pPager->walSyncFlags==0 );
    assert( pPager->ckptSyncFlags==0 );
  }else{
    pPager->fullSync = 1;





    pPager->syncFlags = SQLITE_SYNC_NORMAL;
    pPager->walSyncFlags = SQLITE_SYNC_NORMAL | WAL_SYNC_TRANSACTIONS;
    pPager->ckptSyncFlags = SQLITE_SYNC_NORMAL;
  }
  /* pPager->pFirst = 0; */
  /* pPager->pFirstSynced = 0; */
  /* pPager->pLast = 0; */
................................................................................
  u8 ckptLock;               /* True if holding a checkpoint lock */
  u8 readOnly;               /* WAL_RDWR, WAL_RDONLY, or WAL_SHM_RDONLY */
  u8 truncateOnCommit;       /* True to truncate WAL file on commit */
  u8 syncHeader;             /* Fsync the WAL header if true */
  u8 padToSectorBoundary;    /* Pad transactions out to the next sector */
  WalIndexHdr hdr;           /* Wal-index header for current transaction */
  u32 minFrame;              /* Ignore wal frames before this one */

  const char *zWalName;      /* Name of WAL file */
  u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
#ifdef SQLITE_DEBUG
  u8 lockError;              /* True if a locking error has occurred */
#endif
#ifdef SQLITE_ENABLE_SNAPSHOT
  WalIndexHdr *pSnapshot;    /* Start transaction here if not NULL */
................................................................................
  u8 *aFrame                      /* OUT: Write encoded frame here */
){
  int nativeCksum;                /* True for native byte-order checksums */
  u32 *aCksum = pWal->hdr.aFrameCksum;
  assert( WAL_FRAME_HDRSIZE==24 );
  sqlite3Put4byte(&aFrame[0], iPage);
  sqlite3Put4byte(&aFrame[4], nTruncate);

  memcpy(&aFrame[8], pWal->hdr.aSalt, 8);

  nativeCksum = (pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN);
  walChecksumBytes(nativeCksum, aFrame, 8, aCksum, aCksum);
  walChecksumBytes(nativeCksum, aData, pWal->szPage, aCksum, aCksum);

  sqlite3Put4byte(&aFrame[16], aCksum[0]);
  sqlite3Put4byte(&aFrame[20], aCksum[1]);



}

/*
** Check to see if the frame with header in aFrame[] and content
** in aData[] is valid.  If it is a valid frame, fill *piPage and
** *pnTruncate and return true.  Return if the frame is not valid.
*/
................................................................................
*/
SQLITE_PRIVATE int sqlite3WalBeginWriteTransaction(Wal *pWal){
  int rc;

  /* Cannot start a write transaction without first holding a read
  ** transaction. */
  assert( pWal->readLock>=0 );


  if( pWal->readOnly ){
    return SQLITE_READONLY;
  }

  /* Only one writer allowed at a time.  Get the write lock.  Return
  ** SQLITE_BUSY if unable.
................................................................................
** End a write transaction.  The commit has already been done.  This
** routine merely releases the lock.
*/
SQLITE_PRIVATE int sqlite3WalEndWriteTransaction(Wal *pWal){
  if( pWal->writeLock ){
    walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);
    pWal->writeLock = 0;

    pWal->truncateOnCommit = 0;
  }
  return SQLITE_OK;
}

/*
** If any data has been written (but not committed) to the log file, this
................................................................................
  walEncodeFrame(p->pWal, pPage->pgno, nTruncate, pData, aFrame);
  rc = walWriteToLog(p, aFrame, sizeof(aFrame), iOffset);
  if( rc ) return rc;
  /* Write the page data */
  rc = walWriteToLog(p, pData, p->szPage, iOffset+sizeof(aFrame));
  return rc;
}






















































/* 
** Write a set of frames to the log. The caller must hold the write-lock
** on the log file (obtained using sqlite3WalBeginWriteTransaction()).
*/
SQLITE_PRIVATE int sqlite3WalFrames(
  Wal *pWal,                      /* Wal handle to write to */
................................................................................
  u32 iFrame;                     /* Next frame address */
  PgHdr *p;                       /* Iterator to run through pList with. */
  PgHdr *pLast = 0;               /* Last frame in list */
  int nExtra = 0;                 /* Number of extra copies of last page */
  int szFrame;                    /* The size of a single frame */
  i64 iOffset;                    /* Next byte to write in WAL file */
  WalWriter w;                    /* The writer */



  assert( pList );
  assert( pWal->writeLock );

  /* If this frame set completes a transaction, then nTruncate>0.  If
  ** nTruncate==0 then this frame set does not complete the transaction. */
  assert( (isCommit!=0)==(nTruncate!=0) );
................................................................................

#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
  { int cnt; for(cnt=0, p=pList; p; p=p->pDirty, cnt++){}
    WALTRACE(("WAL%p: frame write begin. %d frames. mxFrame=%d. %s\n",
              pWal, cnt, pWal->hdr.mxFrame, isCommit ? "Commit" : "Spill"));
  }
#endif






  /* See if it is possible to write these frames into the start of the
  ** log file, instead of appending to it at pWal->hdr.mxFrame.
  */
  if( SQLITE_OK!=(rc = walRestartLog(pWal)) ){
    return rc;
  }
................................................................................
  w.szPage = szPage;
  iOffset = walFrameOffset(iFrame+1, szPage);
  szFrame = szPage + WAL_FRAME_HDRSIZE;

  /* Write all frames into the log file exactly once */
  for(p=pList; p; p=p->pDirty){
    int nDbSize;   /* 0 normally.  Positive == commit flag */





















    iFrame++;
    assert( iOffset==walFrameOffset(iFrame, szPage) );
    nDbSize = (isCommit && p->pDirty==0) ? nTruncate : 0;
    rc = walWriteOneFrame(&w, p, nDbSize, iOffset);
    if( rc ) return rc;
    pLast = p;
    iOffset += szFrame;







  }

  /* If this is the end of a transaction, then we might need to pad
  ** the transaction and/or sync the WAL file.
  **
  ** Padding and syncing only occur if this set of frames complete a
  ** transaction and if PRAGMA synchronous=FULL.  If synchronous==NORMAL
................................................................................
  /* Append data to the wal-index. It is not necessary to lock the 
  ** wal-index to do this as the SQLITE_SHM_WRITE lock held on the wal-index
  ** guarantees that there are no other writers, and no data that may
  ** be in use by existing readers is being overwritten.
  */
  iFrame = pWal->hdr.mxFrame;
  for(p=pList; p && rc==SQLITE_OK; p=p->pDirty){

    iFrame++;
    rc = walIndexAppend(pWal, iFrame, p->pgno);
  }
  while( rc==SQLITE_OK && nExtra>0 ){
    iFrame++;
    nExtra--;
    rc = walIndexAppend(pWal, iFrame, pLast->pgno);
................................................................................
    if( isChanged && pWal->pDbFd->pMethods->iVersion>=3 ){
      sqlite3OsUnfetch(pWal->pDbFd, 0, 0);
    }
  }

  /* Copy data from the log to the database file. */
  if( rc==SQLITE_OK ){

    if( pWal->hdr.mxFrame && walPagesize(pWal)!=nBuf ){
      rc = SQLITE_CORRUPT_BKPT;
    }else{
      rc = walCheckpoint(pWal, eMode2, xBusy2, pBusyArg, sync_flags, zBuf);
    }

    /* If no error occurred, set the output variables. */
................................................................................
** stored in MemPage.pBt->mutex.
*/
struct MemPage {
  u8 isInit;           /* True if previously initialized. MUST BE FIRST! */
  u8 nOverflow;        /* Number of overflow cell bodies in aCell[] */
  u8 intKey;           /* True if table b-trees.  False for index b-trees */
  u8 intKeyLeaf;       /* True if the leaf of an intKey table */
  u8 noPayload;        /* True if internal intKey page (thus w/o data) */
  u8 leaf;             /* True if a leaf page */
  u8 hdrOffset;        /* 100 for page 1.  0 otherwise */
  u8 childPtrSize;     /* 0 if leaf==1.  4 if leaf==0 */
  u8 max1bytePayload;  /* min(maxLocal,127) */
  u8 bBusy;            /* Prevent endless loops on corrupt database files */
  u16 maxLocal;        /* Copy of BtShared.maxLocal or BtShared.maxLeaf */
  u16 minLocal;        /* Copy of BtShared.minLocal or BtShared.minLeaf */
................................................................................
  assert( p->sharable==0 || p->locked==0 || sqlite3_mutex_held(p->pBt->mutex) );
  assert( p->sharable==0 || p->locked==0 || sqlite3_mutex_held(p->db->mutex) );

  return (p->sharable==0 || p->locked);
}
#endif


#ifndef SQLITE_OMIT_INCRBLOB
/*
** Enter and leave a mutex on a Btree given a cursor owned by that
** Btree.  These entry points are used by incremental I/O and can be
** omitted if that module is not used.
*/
SQLITE_PRIVATE void sqlite3BtreeEnterCursor(BtCursor *pCur){
  sqlite3BtreeEnter(pCur->pBtree);
}
SQLITE_PRIVATE void sqlite3BtreeLeaveCursor(BtCursor *pCur){
  sqlite3BtreeLeave(pCur->pBtree);
}
#endif /* SQLITE_OMIT_INCRBLOB */


/*
** Enter the mutex on every Btree associated with a database
** connection.  This is needed (for example) prior to parsing
** a statement since we will be comparing table and column names
** against all schemas and we do not want those schemas being
** reset out from under us.
................................................................................
  assert( sqlite3_mutex_held(db->mutex) );
  for(i=0; i<db->nDb; i++){
    p = db->aDb[i].pBt;
    if( p ) sqlite3BtreeLeave(p);
  }
}

/*
** Return true if a particular Btree requires a lock.  Return FALSE if
** no lock is ever required since it is not sharable.
*/
SQLITE_PRIVATE int sqlite3BtreeSharable(Btree *p){
  return p->sharable;
}

#ifndef NDEBUG
/*
** Return true if the current thread holds the database connection
** mutex and all required BtShared mutexes.
**
** This routine is used inside assert() statements only.
*/
................................................................................
    Btree *p = db->aDb[i].pBt;
    if( p ){
      p->pBt->db = p->db;
    }
  }
}
#endif /* if SQLITE_THREADSAFE */



















#endif /* ifndef SQLITE_OMIT_SHARED_CACHE */

/************** End of btmutex.c *********************************************/
/************** Begin file btree.c *******************************************/
/*
** 2004 April 6
**
................................................................................
**
** Verify that the cursor holds the mutex on its BtShared
*/
#ifdef SQLITE_DEBUG
static int cursorHoldsMutex(BtCursor *p){
  return sqlite3_mutex_held(p->pBt->mutex);
}




#endif

/*
** Invalidate the overflow cache of the cursor passed as the first argument.
** on the shared btree structure pBt.
*/
#define invalidateOverflowCache(pCur) (pCur->curFlags &= ~BTCF_ValidOvfl)
................................................................................
** saved position info stored by saveCursorPosition(), so there can be
** at most one effective restoreCursorPosition() call after each 
** saveCursorPosition().
*/
static int btreeRestoreCursorPosition(BtCursor *pCur){
  int rc;
  int skipNext;
  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState>=CURSOR_REQUIRESEEK );
  if( pCur->eState==CURSOR_FAULT ){
    return pCur->skipNext;
  }
  pCur->eState = CURSOR_INVALID;
  rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &skipNext);
  if( rc==SQLITE_OK ){
................................................................................
static void btreeParseCellPtrNoPayload(
  MemPage *pPage,         /* Page containing the cell */
  u8 *pCell,              /* Pointer to the cell text. */
  CellInfo *pInfo         /* Fill in this structure */
){
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( pPage->leaf==0 );
  assert( pPage->noPayload );
  assert( pPage->childPtrSize==4 );
#ifndef SQLITE_DEBUG
  UNUSED_PARAMETER(pPage);
#endif
  pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey);
  pInfo->nPayload = 0;
  pInfo->nLocal = 0;
................................................................................
){
  u8 *pIter;              /* For scanning through pCell */
  u32 nPayload;           /* Number of bytes of cell payload */
  u64 iKey;               /* Extracted Key value */

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( pPage->leaf==0 || pPage->leaf==1 );
  assert( pPage->intKeyLeaf || pPage->noPayload );
  assert( pPage->noPayload==0 );
  assert( pPage->intKeyLeaf );
  assert( pPage->childPtrSize==0 );
  pIter = pCell;

  /* The next block of code is equivalent to:
  **
  **     pIter += getVarint32(pIter, nPayload);
................................................................................
){
  u8 *pIter;              /* For scanning through pCell */
  u32 nPayload;           /* Number of bytes of cell payload */

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( pPage->leaf==0 || pPage->leaf==1 );
  assert( pPage->intKeyLeaf==0 );
  assert( pPage->noPayload==0 );
  pIter = pCell + pPage->childPtrSize;
  nPayload = *pIter;
  if( nPayload>=0x80 ){
    u8 *pEnd = &pIter[8];
    nPayload &= 0x7f;
    do{
      nPayload = (nPayload<<7) | (*++pIter & 0x7f);
................................................................................
  ** the (CellInfo.nSize) value found by doing a full parse of the
  ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of
  ** this function verifies that this invariant is not violated. */
  CellInfo debuginfo;
  pPage->xParseCell(pPage, pCell, &debuginfo);
#endif

  assert( pPage->noPayload==0 );
  nSize = *pIter;
  if( nSize>=0x80 ){
    pEnd = &pIter[8];
    nSize &= 0x7f;
    do{
      nSize = (nSize<<7) | (*++pIter & 0x7f);
    }while( *(pIter)>=0x80 && pIter<pEnd );
................................................................................
    assert( (PTF_LEAFDATA|PTF_INTKEY)==5 );
    /* EVIDENCE-OF: R-20501-61796 A value of 13 means the page is a leaf
    ** table b-tree page. */
    assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 );
    pPage->intKey = 1;
    if( pPage->leaf ){
      pPage->intKeyLeaf = 1;
      pPage->noPayload = 0;
      pPage->xParseCell = btreeParseCellPtr;
    }else{
      pPage->intKeyLeaf = 0;
      pPage->noPayload = 1;
      pPage->xCellSize = cellSizePtrNoPayload;
      pPage->xParseCell = btreeParseCellPtrNoPayload;
    }
    pPage->maxLocal = pBt->maxLeaf;
    pPage->minLocal = pBt->minLeaf;
  }else if( flagByte==PTF_ZERODATA ){
    /* EVIDENCE-OF: R-27225-53936 A value of 2 means the page is an interior
................................................................................
    ** index b-tree page. */
    assert( (PTF_ZERODATA)==2 );
    /* EVIDENCE-OF: R-16571-11615 A value of 10 means the page is a leaf
    ** index b-tree page. */
    assert( (PTF_ZERODATA|PTF_LEAF)==10 );
    pPage->intKey = 0;
    pPage->intKeyLeaf = 0;
    pPage->noPayload = 0;
    pPage->xParseCell = btreeParseCellPtrIndex;
    pPage->maxLocal = pBt->maxLocal;
    pPage->minLocal = pBt->minLocal;
  }else{
    /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is
    ** an error. */
    return SQLITE_CORRUPT_BKPT;
................................................................................
      MUTEX_LOGIC( sqlite3_mutex *mutexShared; )
      pBt->nRef = 1;
      MUTEX_LOGIC( mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);)
      if( SQLITE_THREADSAFE && sqlite3GlobalConfig.bCoreMutex ){
        pBt->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_FAST);
        if( pBt->mutex==0 ){
          rc = SQLITE_NOMEM;
          db->mallocFailed = 0;
          goto btree_open_out;
        }
      }
      sqlite3_mutex_enter(mutexShared);
      pBt->pNext = GLOBAL(BtShared*,sqlite3SharedCacheList);
      GLOBAL(BtShared*,sqlite3SharedCacheList) = pBt;
      sqlite3_mutex_leave(mutexShared);
................................................................................
** of A's read lock.  A tries to promote to reserved but is blocked by B.
** One or the other of the two processes must give way or there can be
** no progress.  By returning SQLITE_BUSY and not invoking the busy callback
** when A already has a read lock, we encourage A to give up and let B
** proceed.
*/
SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
  sqlite3 *pBlock = 0;
  BtShared *pBt = p->pBt;
  int rc = SQLITE_OK;

  sqlite3BtreeEnter(p);
  btreeIntegrity(p);

  /* If the btree is already in a write-transaction, or it
................................................................................
  /* Write transactions are not possible on a read-only database */
  if( (pBt->btsFlags & BTS_READ_ONLY)!=0 && wrflag ){
    rc = SQLITE_READONLY;
    goto trans_begun;
  }

#ifndef SQLITE_OMIT_SHARED_CACHE


  /* If another database handle has already opened a write transaction 
  ** on this shared-btree structure and a second write transaction is
  ** requested, return SQLITE_LOCKED.
  */
  if( (wrflag && pBt->inTransaction==TRANS_WRITE)
   || (pBt->btsFlags & BTS_PENDING)!=0
  ){
    pBlock = pBt->pWriter->db;
  }else if( wrflag>1 ){
    BtLock *pIter;
    for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){
      if( pIter->pBtree!=p ){
        pBlock = pIter->pBtree->db;
        break;
      }
    }
  }
  if( pBlock ){
    sqlite3ConnectionBlocked(p->db, pBlock);
    rc = SQLITE_LOCKED_SHAREDCACHE;
    goto trans_begun;

  }
#endif

  /* Any read-only or read-write transaction implies a read-lock on 
  ** page 1. So if some other shared-cache client already has a write-lock 
  ** on page 1, the transaction cannot be opened. */
  rc = querySharedCacheTableLock(p, MASTER_ROOT, READ_LOCK);
................................................................................
/*
** Create a new cursor for the BTree whose root is on the page
** iTable. If a read-only cursor is requested, it is assumed that
** the caller already has at least a read-only transaction open
** on the database already. If a write-cursor is requested, then
** the caller is assumed to have an open write transaction.
**
** If wrFlag==0, then the cursor can only be used for reading.
** If wrFlag==1, then the cursor can be used for reading or for
** writing if other conditions for writing are also met.  These
** are the conditions that must be met in order for writing to
** be allowed:
**
** 1:  The cursor must have been opened with wrFlag==1
**
** 2:  Other database connections that share the same pager cache
**     but which are not in the READ_UNCOMMITTED state may not have
**     cursors open with wrFlag==0 on the same table.  Otherwise
**     the changes made by this write cursor would be visible to
**     the read cursors in the other database connection.
**
** 3:  The database must be writable (not on read-only media)
**
** 4:  There must be an active transaction.










**
** No checking is done to make sure that page iTable really is the
** root page of a b-tree.  If it is not, then the cursor acquired
** will not work correctly.
**
** It is assumed that the sqlite3BtreeCursorZero() has been called
** on pCur to initialize the memory space prior to invoking this routine.
................................................................................
** that the cursor has Cursor.eState==CURSOR_VALID.
**
** Failure is not possible.  This function always returns SQLITE_OK.
** It might just as well be a procedure (returning void) but we continue
** to return an integer result code for historical reasons.
*/
SQLITE_PRIVATE int sqlite3BtreeDataSize(BtCursor *pCur, u32 *pSize){
  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  assert( pCur->iPage>=0 );
  assert( pCur->iPage<BTCURSOR_MAX_DEPTH );
  assert( pCur->apPage[pCur->iPage]->intKeyLeaf==1 );
  getCellInfo(pCur);
  *pSize = pCur->info.nPayload;
  return SQLITE_OK;
................................................................................

#ifndef SQLITE_OMIT_INCRBLOB
  if ( pCur->eState==CURSOR_INVALID ){
    return SQLITE_ABORT;
  }
#endif

  assert( cursorHoldsMutex(pCur) );
  rc = restoreCursorPosition(pCur);
  if( rc==SQLITE_OK ){
    assert( pCur->eState==CURSOR_VALID );
    assert( pCur->iPage>=0 && pCur->apPage[pCur->iPage] );
    assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
    rc = accessPayload(pCur, offset, amt, pBuf, 0);
  }
................................................................................
  BtCursor *pCur,      /* Cursor pointing to entry to read from */
  u32 *pAmt            /* Write the number of available bytes here */
){
  u32 amt;
  assert( pCur!=0 && pCur->iPage>=0 && pCur->apPage[pCur->iPage]);
  assert( pCur->eState==CURSOR_VALID );
  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
  assert( cursorHoldsMutex(pCur) );
  assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
  assert( pCur->info.nSize>0 );
  assert( pCur->info.pPayload>pCur->apPage[pCur->iPage]->aData || CORRUPT_DB );
  assert( pCur->info.pPayload<pCur->apPage[pCur->iPage]->aDataEnd ||CORRUPT_DB);
  amt = (int)(pCur->apPage[pCur->iPage]->aDataEnd - pCur->info.pPayload);
  if( pCur->info.nLocal<amt ) amt = pCur->info.nLocal;
  *pAmt = amt;
................................................................................
** the new child page does not match the flags field of the parent (i.e.
** if an intkey page appears to be the parent of a non-intkey page, or
** vice-versa).
*/
static int moveToChild(BtCursor *pCur, u32 newPgno){
  BtShared *pBt = pCur->pBt;

  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  assert( pCur->iPage<BTCURSOR_MAX_DEPTH );
  assert( pCur->iPage>=0 );
  if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){
    return SQLITE_CORRUPT_BKPT;
  }
  pCur->info.nSize = 0;
................................................................................
**
** pCur->idx is set to the cell index that contains the pointer
** to the page we are coming from.  If we are coming from the
** right-most child page then pCur->idx is set to one more than
** the largest cell index.
*/
static void moveToParent(BtCursor *pCur){
  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  assert( pCur->iPage>0 );
  assert( pCur->apPage[pCur->iPage] );
  assertParentIndex(
    pCur->apPage[pCur->iPage-1], 
    pCur->aiIdx[pCur->iPage-1], 
    pCur->apPage[pCur->iPage]->pgno
................................................................................
** structure the flags byte is set to 0x02 or 0x0A, indicating an index
** b-tree).
*/
static int moveToRoot(BtCursor *pCur){
  MemPage *pRoot;
  int rc = SQLITE_OK;

  assert( cursorHoldsMutex(pCur) );
  assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
  assert( CURSOR_VALID   < CURSOR_REQUIRESEEK );
  assert( CURSOR_FAULT   > CURSOR_REQUIRESEEK );
  if( pCur->eState>=CURSOR_REQUIRESEEK ){
    if( pCur->eState==CURSOR_FAULT ){
      assert( pCur->skipNext!=SQLITE_OK );
      return pCur->skipNext;
................................................................................
** in ascending order.
*/
static int moveToLeftmost(BtCursor *pCur){
  Pgno pgno;
  int rc = SQLITE_OK;
  MemPage *pPage;

  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  while( rc==SQLITE_OK && !(pPage = pCur->apPage[pCur->iPage])->leaf ){
    assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
    pgno = get4byte(findCell(pPage, pCur->aiIdx[pCur->iPage]));
    rc = moveToChild(pCur, pgno);
  }
  return rc;
................................................................................
** key in ascending order.
*/
static int moveToRightmost(BtCursor *pCur){
  Pgno pgno;
  int rc = SQLITE_OK;
  MemPage *pPage = 0;

  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  while( !(pPage = pCur->apPage[pCur->iPage])->leaf ){
    pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
    pCur->aiIdx[pCur->iPage] = pPage->nCell;
    rc = moveToChild(pCur, pgno);
    if( rc ) return rc;
  }
................................................................................
/* Move the cursor to the first entry in the table.  Return SQLITE_OK
** on success.  Set *pRes to 0 if the cursor actually points to something
** or set *pRes to 1 if the table is empty.
*/
SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
  int rc;

  assert( cursorHoldsMutex(pCur) );
  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
  rc = moveToRoot(pCur);
  if( rc==SQLITE_OK ){
    if( pCur->eState==CURSOR_INVALID ){
      assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage]->nCell==0 );
      *pRes = 1;
    }else{
................................................................................
/* Move the cursor to the last entry in the table.  Return SQLITE_OK
** on success.  Set *pRes to 0 if the cursor actually points to something
** or set *pRes to 1 if the table is empty.
*/
SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
  int rc;
 
  assert( cursorHoldsMutex(pCur) );
  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );

  /* If the cursor already points to the last entry, this is a no-op. */
  if( CURSOR_VALID==pCur->eState && (pCur->curFlags & BTCF_AtLast)!=0 ){
#ifdef SQLITE_DEBUG
    /* This block serves to assert() that the cursor really does point 
    ** to the last entry in the b-tree. */
................................................................................
  i64 intKey,              /* The table key */
  int biasRight,           /* If true, bias the search to the high end */
  int *pRes                /* Write search results here */
){
  int rc;
  RecordCompare xRecordCompare;

  assert( cursorHoldsMutex(pCur) );
  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
  assert( pRes );
  assert( (pIdxKey==0)==(pCur->pKeyInfo==0) );

  /* If the cursor is already positioned at the point we are trying
  ** to move to, then just return without doing any work */
  if( pCur->eState==CURSOR_VALID && (pCur->curFlags & BTCF_ValidNKey)!=0
................................................................................
** implementation does use this hint, however.)
*/
static SQLITE_NOINLINE int btreeNext(BtCursor *pCur, int *pRes){
  int rc;
  int idx;
  MemPage *pPage;

  assert( cursorHoldsMutex(pCur) );
  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
  assert( *pRes==0 );
  if( pCur->eState!=CURSOR_VALID ){
    assert( (pCur->curFlags & BTCF_ValidOvfl)==0 );
    rc = restoreCursorPosition(pCur);
    if( rc!=SQLITE_OK ){
      return rc;
................................................................................
    return SQLITE_OK;
  }else{
    return moveToLeftmost(pCur);
  }
}
SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
  MemPage *pPage;
  assert( cursorHoldsMutex(pCur) );
  assert( pRes!=0 );
  assert( *pRes==0 || *pRes==1 );
  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
  pCur->info.nSize = 0;
  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
  *pRes = 0;
  if( pCur->eState!=CURSOR_VALID ) return btreeNext(pCur, pRes);
................................................................................
** SQLite btree implementation does not. (Note that the comdb2 btree
** implementation does use this hint, however.)
*/
static SQLITE_NOINLINE int btreePrevious(BtCursor *pCur, int *pRes){
  int rc;
  MemPage *pPage;

  assert( cursorHoldsMutex(pCur) );
  assert( pRes!=0 );
  assert( *pRes==0 );
  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
  assert( (pCur->curFlags & (BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey))==0 );
  assert( pCur->info.nSize==0 );
  if( pCur->eState!=CURSOR_VALID ){
    rc = restoreCursorPosition(pCur);
................................................................................
    }else{
      rc = SQLITE_OK;
    }
  }
  return rc;
}
SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
  assert( cursorHoldsMutex(pCur) );
  assert( pRes!=0 );
  assert( *pRes==0 || *pRes==1 );
  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
  *pRes = 0;
  pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey);
  pCur->info.nSize = 0;
  if( pCur->eState!=CURSOR_VALID
................................................................................
  ** Use a call to btreeParseCellPtr() to verify that the values above
  ** were computed correctly.
  */
#if SQLITE_DEBUG
  {
    CellInfo info;
    pPage->xParseCell(pPage, pCell, &info);
    assert( nHeader=(int)(info.pPayload - pCell) );
    assert( info.nKey==nKey );
    assert( *pnSize == info.nSize );
    assert( spaceLeft == info.nLocal );
  }
#endif

  /* Write the payload into the local Cell and any extra into overflow pages */
................................................................................
    ** invariant.
    **
    ** This must be done in advance.  Once the balance starts, the cell
    ** offset section of the btree page will be overwritten and we will no
    ** long be able to find the cells if a pointer to each cell is not saved
    ** first.
    */
    memset(&b.szCell[b.nCell], 0, sizeof(b.szCell[0])*limit);
    if( pOld->nOverflow>0 ){
      memset(&b.szCell[b.nCell+limit], 0, sizeof(b.szCell[0])*pOld->nOverflow);
      limit = pOld->aiOvfl[0];
      for(j=0; j<limit; j++){
        b.apCell[b.nCell] = aData + (maskPage & get2byteAligned(piCell));
        piCell += 2;
        b.nCell++;
      }
      for(k=0; k<pOld->nOverflow; k++){
................................................................................
*/
static int balance(BtCursor *pCur){
  int rc = SQLITE_OK;
  const int nMin = pCur->pBt->usableSize * 2 / 3;
  u8 aBalanceQuickSpace[13];
  u8 *pFree = 0;

  TESTONLY( int balance_quick_called = 0 );
  TESTONLY( int balance_deeper_called = 0 );

  do {
    int iPage = pCur->iPage;
    MemPage *pPage = pCur->apPage[iPage];

    if( iPage==0 ){
      if( pPage->nOverflow ){
        /* The root page of the b-tree is overfull. In this case call the
        ** balance_deeper() function to create a new child for the root-page
        ** and copy the current contents of the root-page to it. The
        ** next iteration of the do-loop will balance the child page.
        */ 

        assert( (balance_deeper_called++)==0 );
        rc = balance_deeper(pPage, &pCur->apPage[1]);
        if( rc==SQLITE_OK ){
          pCur->iPage = 1;
          pCur->aiIdx[0] = 0;
          pCur->aiIdx[1] = 0;
          assert( pCur->apPage[1]->nOverflow );
        }
................................................................................
          ** buffer. 
          **
          ** The purpose of the following assert() is to check that only a
          ** single call to balance_quick() is made for each call to this
          ** function. If this were not verified, a subtle bug involving reuse
          ** of the aBalanceQuickSpace[] might sneak in.
          */

          assert( (balance_quick_called++)==0 );
          rc = balance_quick(pParent, pPage, aBalanceQuickSpace);
        }else
#endif
        {
          /* In this case, call balance_nonroot() to redistribute cells
          ** between pPage and up to 2 of its sibling pages. This involves
          ** modifying the contents of pParent, which may cause pParent to
................................................................................
  unsigned char *newCell = 0;

  if( pCur->eState==CURSOR_FAULT ){
    assert( pCur->skipNext!=SQLITE_OK );
    return pCur->skipNext;
  }

  assert( cursorHoldsMutex(pCur) );
  assert( (pCur->curFlags & BTCF_WriteFlag)!=0
              && pBt->inTransaction==TRANS_WRITE
              && (pBt->btsFlags & BTS_READ_ONLY)==0 );
  assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );

  /* Assert that the caller has been consistent. If this cursor was opened
  ** expecting an index b-tree, then the caller should be inserting blob
................................................................................
end_insert:
  return rc;
}

/*
** Delete the entry that the cursor is pointing to. 
**
** If the second parameter is zero, then the cursor is left pointing at an
** arbitrary location after the delete. If it is non-zero, then the cursor 

** is left in a state such that the next call to BtreeNext() or BtreePrev()
** moves it to the same row as it would if the call to BtreeDelete() had
** been omitted.








*/
SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur, int bPreserve){
  Btree *p = pCur->pBtree;
  BtShared *pBt = p->pBt;              
  int rc;                              /* Return code */
  MemPage *pPage;                      /* Page to delete cell from */
  unsigned char *pCell;                /* Pointer to cell to delete */
  int iCellIdx;                        /* Index of cell to delete */
  int iCellDepth;                      /* Depth of node containing pCell */ 
  u16 szCell;                          /* Size of the cell being deleted */
  int bSkipnext = 0;                   /* Leaf cursor in SKIPNEXT state */


  assert( cursorHoldsMutex(pCur) );
  assert( pBt->inTransaction==TRANS_WRITE );
  assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );
  assert( pCur->curFlags & BTCF_WriteFlag );
  assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );
  assert( !hasReadConflicts(p, pCur->pgnoRoot) );
  assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
  assert( pCur->eState==CURSOR_VALID );


  iCellDepth = pCur->iPage;
  iCellIdx = pCur->aiIdx[iCellDepth];
  pPage = pCur->apPage[iCellDepth];
  pCell = findCell(pPage, iCellIdx);

  /* If the page containing the entry to delete is not a leaf page, move
................................................................................
    }
    rc = balance(pCur);
  }

  if( rc==SQLITE_OK ){
    if( bSkipnext ){
      assert( bPreserve && (pCur->iPage==iCellDepth || CORRUPT_DB) );
      assert( pPage==pCur->apPage[pCur->iPage] );
      assert( (pPage->nCell>0 || CORRUPT_DB) && iCellIdx<=pPage->nCell );
      pCur->eState = CURSOR_SKIPNEXT;
      if( iCellIdx>=pPage->nCell ){
        pCur->skipNext = -1;
        pCur->aiIdx[iCellDepth] = pPage->nCell-1;
      }else{
        pCur->skipNext = 1;
................................................................................
  **
  ** This error is caught long before control reaches this point.
  */
  if( NEVER(pBt->pCursor) ){
    sqlite3ConnectionBlocked(p->db, pBt->pCursor->pBtree->db);
    return SQLITE_LOCKED_SHAREDCACHE;
  }









  rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0);
  if( rc ) return rc;
  rc = sqlite3BtreeClearTable(p, iTable, 0);
  if( rc ){
    releasePage(pPage);
    return rc;
  }

  *piMoved = 0;

  if( iTable>1 ){
#ifdef SQLITE_OMIT_AUTOVACUUM
    freePage(pPage, &rc);
    releasePage(pPage);
#else
    if( pBt->autoVacuum ){
      Pgno maxRootPgno;
      sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, &maxRootPgno);

      if( iTable==maxRootPgno ){
        /* If the table being dropped is the table with the largest root-page
        ** number in the database, put the root page on the free list. 
        */
        freePage(pPage, &rc);
        releasePage(pPage);
        if( rc!=SQLITE_OK ){
          return rc;
        }
      }else{
        /* The table being dropped does not have the largest root-page
        ** number in the database. So move the page that does into the 
        ** gap left by the deleted root-page.
        */
        MemPage *pMove;
        releasePage(pPage);
        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        rc = relocatePage(pBt, pMove, PTRMAP_ROOTPAGE, 0, iTable, 0);
        releasePage(pMove);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        pMove = 0;
        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
        freePage(pMove, &rc);
        releasePage(pMove);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        *piMoved = maxRootPgno;
      }

      /* Set the new 'max-root-page' value in the database header. This
      ** is the old value less one, less one more if that happens to
      ** be a root-page number, less one again if that is the
      ** PENDING_BYTE_PAGE.
      */
      maxRootPgno--;
      while( maxRootPgno==PENDING_BYTE_PAGE(pBt)
             || PTRMAP_ISPAGE(pBt, maxRootPgno) ){
        maxRootPgno--;
      }
      assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );

      rc = sqlite3BtreeUpdateMeta(p, 4, maxRootPgno);
    }else{
      freePage(pPage, &rc);
      releasePage(pPage);
    }
#endif
  }else{
    /* If sqlite3BtreeDropTable was called on page 1.
    ** This really never should happen except in a corrupt
    ** database. 
    */
    zeroPage(pPage, PTF_INTKEY|PTF_LEAF );
    releasePage(pPage);
  }
  return rc;  
}
SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree *p, int iTable, int *piMoved){
  int rc;
  sqlite3BtreeEnter(p);
  rc = btreeDropTable(p, iTable, piMoved);
  sqlite3BtreeLeave(p);
................................................................................
  pCheck->mxErr--;
  pCheck->nErr++;
  va_start(ap, zFormat);
  if( pCheck->errMsg.nChar ){
    sqlite3StrAccumAppend(&pCheck->errMsg, "\n", 1);
  }
  if( pCheck->zPfx ){
    sqlite3XPrintf(&pCheck->errMsg, 0, pCheck->zPfx, pCheck->v1, pCheck->v2);
  }
  sqlite3VXPrintf(&pCheck->errMsg, 1, zFormat, ap);
  va_end(ap);
  if( pCheck->errMsg.accError==STRACCUM_NOMEM ){
    pCheck->mallocFailed = 1;
  }
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

................................................................................
  BtShared *pBt = p->pBt;
  int savedDbFlags = pBt->db->flags;
  char zErr[100];
  VVA_ONLY( int nRef );

  sqlite3BtreeEnter(p);
  assert( p->inTrans>TRANS_NONE && pBt->inTransaction>TRANS_NONE );
  assert( (nRef = sqlite3PagerRefcount(pBt->pPager))>=0 );

  sCheck.pBt = pBt;
  sCheck.pPager = pBt->pPager;
  sCheck.nPage = btreePagecount(sCheck.pBt);
  sCheck.mxErr = mxErr;
  sCheck.nErr = 0;
  sCheck.mallocFailed = 0;
  sCheck.zPfx = 0;
  sCheck.v1 = 0;
  sCheck.v2 = 0;
  sCheck.aPgRef = 0;
  sCheck.heap = 0;
  sqlite3StrAccumInit(&sCheck.errMsg, 0, zErr, sizeof(zErr), SQLITE_MAX_LENGTH);

  if( sCheck.nPage==0 ){
    goto integrity_ck_cleanup;
  }

  sCheck.aPgRef = sqlite3MallocZero((sCheck.nPage / 8)+ 1);
  if( !sCheck.aPgRef ){
    sCheck.mallocFailed = 1;
................................................................................
** Only the data content may only be modified, it is not possible to 
** change the length of the data stored. If this function is called with
** parameters that attempt to write past the end of the existing data,
** no modifications are made and SQLITE_CORRUPT is returned.
*/
SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){
  int rc;
  assert( cursorHoldsMutex(pCsr) );
  assert( sqlite3_mutex_held(pCsr->pBtree->db->mutex) );
  assert( pCsr->curFlags & BTCF_Incrblob );

  rc = restoreCursorPosition(pCsr);
  if( rc!=SQLITE_OK ){
    return rc;
  }
................................................................................
  return (p->pBt->btsFlags & BTS_READ_ONLY)!=0;
}

/*
** Return the size of the header added to each page by this module.
*/
SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void){ return ROUND8(sizeof(MemPage)); }










/************** End of btree.c ***********************************************/
/************** Begin file backup.c ******************************************/
/*
** 2009 January 28
**
** The author disclaims copyright to this source code.  In place of
................................................................................
** pMem->z into the new allocation.  pMem must be either a string or
** blob if bPreserve is true.  If bPreserve is false, any prior content
** in pMem->z is discarded.
*/
SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
  assert( sqlite3VdbeCheckMemInvariants(pMem) );
  assert( (pMem->flags&MEM_RowSet)==0 );


  /* If the bPreserve flag is set to true, then the memory cell must already
  ** contain a valid string or blob value.  */
  assert( bPreserve==0 || pMem->flags&(MEM_Blob|MEM_Str) );
  testcase( bPreserve && pMem->z==0 );

  assert( pMem->szMalloc==0
................................................................................
** empty boolean index.
*/
SQLITE_PRIVATE void sqlite3VdbeMemSetRowSet(Mem *pMem){
  sqlite3 *db = pMem->db;
  assert( db!=0 );
  assert( (pMem->flags & MEM_RowSet)==0 );
  sqlite3VdbeMemRelease(pMem);
  pMem->zMalloc = sqlite3DbMallocRaw(db, 64);
  if( db->mallocFailed ){
    pMem->flags = MEM_Null;
    pMem->szMalloc = 0;
  }else{
    assert( pMem->zMalloc );
    pMem->szMalloc = sqlite3DbMallocSize(db, pMem->zMalloc);
    pMem->u.pRowSet = sqlite3RowSetInit(db, pMem->zMalloc, pMem->szMalloc);
................................................................................
    goto value_from_function_out;
  }

  assert( pCtx->pParse->rc==SQLITE_OK );
  memset(&ctx, 0, sizeof(ctx));
  ctx.pOut = pVal;
  ctx.pFunc = pFunc;
  pFunc->xFunc(&ctx, nVal, apVal);
  if( ctx.isError ){
    rc = ctx.isError;
    sqlite3ErrorMsg(pCtx->pParse, "%s", sqlite3_value_text(pVal));
  }else{
    sqlite3ValueApplyAffinity(pVal, aff, SQLITE_UTF8);
    assert( rc==SQLITE_OK );
    rc = sqlite3VdbeChangeEncoding(pVal, enc);
................................................................................
  }
#endif

  *ppVal = pVal;
  return rc;

no_mem:
  db->mallocFailed = 1;
  sqlite3DbFree(db, zVal);
  assert( *ppVal==0 );
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( pCtx==0 ) sqlite3ValueFree(pVal);
#else
  assert( pCtx==0 ); sqlite3ValueFree(pVal);
#endif
................................................................................

  UNUSED_PARAMETER( argc );
  iSerial = sqlite3VdbeSerialType(argv[0], file_format, &nVal);
  nSerial = sqlite3VarintLen(iSerial);
  db = sqlite3_context_db_handle(context);

  nRet = 1 + nSerial + nVal;
  aRet = sqlite3DbMallocRaw(db, nRet);
  if( aRet==0 ){
    sqlite3_result_error_nomem(context);
  }else{
    aRet[0] = nSerial+1;
    putVarint32(&aRet[1], iSerial);
    sqlite3VdbeSerialPut(&aRet[1+nSerial], argv[0], iSerial);
    sqlite3_result_blob(context, aRet, nRet, SQLITE_TRANSIENT);
................................................................................
}
SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
  int i;
  VdbeOp *pOp;

  i = p->nOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  assert( op>0 && op<0xff );
  if( p->pParse->nOpAlloc<=i ){
    return growOp3(p, op, p1, p2, p3);
  }
  p->nOp++;
  pOp = &p->aOp[i];
  pOp->opcode = (u8)op;
  pOp->p5 = 0;
................................................................................
  va_list ap;
  int i;
  char c;
  va_start(ap, zTypes);
  for(i=0; (c = zTypes[i])!=0; i++){
    if( c=='s' ){
      const char *z = va_arg(ap, const char*);
      int addr = sqlite3VdbeAddOp2(p, z==0 ? OP_Null : OP_String8, 0, iDest++);
      if( z ) sqlite3VdbeChangeP4(p, addr, z, 0);
    }else{
      assert( c=='i' );
      sqlite3VdbeAddOp2(p, OP_Integer, va_arg(ap, int), iDest++);
    }
  }
  va_end(ap);
}
................................................................................
  int op,             /* The new opcode */
  int p1,             /* The P1 operand */
  int p2,             /* The P2 operand */
  int p3,             /* The P3 operand */
  const u8 *zP4,      /* The P4 operand */
  int p4type          /* P4 operand type */
){
  char *p4copy = sqlite3DbMallocRaw(sqlite3VdbeDb(p), 8);
  if( p4copy ) memcpy(p4copy, zP4, 8);
  return sqlite3VdbeAddOp4(p, op, p1, p2, p3, p4copy, p4type);
}

/*
** Add an OP_ParseSchema opcode.  This routine is broken out from
** sqlite3VdbeAddOp4() since it needs to also needs to mark all btrees
................................................................................
** as having been used.
**
** The zWhere string must have been obtained from sqlite3_malloc().
** This routine will take ownership of the allocated memory.
*/
SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere){
  int j;
  int addr = sqlite3VdbeAddOp3(p, OP_ParseSchema, iDb, 0, 0);
  sqlite3VdbeChangeP4(p, addr, zWhere, P4_DYNAMIC);
  for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);
}

/*
** Add an opcode that includes the p4 value as an integer.
*/
SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(
................................................................................
  int p3,             /* The P3 operand */
  int p4              /* The P4 operand as an integer */
){
  int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);
  sqlite3VdbeChangeP4(p, addr, SQLITE_INT_TO_PTR(p4), P4_INT32);
  return addr;
}
















/*
** Create a new symbolic label for an instruction that has yet to be
** coded.  The symbolic label is really just a negative number.  The
** label can be used as the P2 value of an operation.  Later, when
** the label is resolved to a specific address, the VDBE will scan
** through its operation list and change all values of P2 which match
................................................................................
  Parse *pParse = p->pParse;
  int *aLabel = pParse->aLabel;
  p->readOnly = 1;
  p->bIsReader = 0;
  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
    u8 opcode = pOp->opcode;

    /* NOTE: Be sure to update mkopcodeh.awk when adding or removing
    ** cases from this switch! */
    switch( opcode ){
      case OP_Transaction: {
        if( pOp->p2!=0 ) p->readOnly = 0;
        /* fall thru */
      }
      case OP_AutoCommit:
................................................................................
** Return the address of the next instruction to be inserted.
*/
SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe *p){
  assert( p->magic==VDBE_MAGIC_INIT );
  return p->nOp;
}















/*
** This function returns a pointer to the array of opcodes associated with
** the Vdbe passed as the first argument. It is the callers responsibility
** to arrange for the returned array to be eventually freed using the 
** vdbeFreeOpArray() function.
**
** Before returning, *pnOp is set to the number of entries in the returned
................................................................................
  resolveP2Values(p, pnMaxArg);
  *pnOp = p->nOp;
  p->aOp = 0;
  return aOp;
}

/*
** Add a whole list of operations to the operation stack.  Return the
** address of the first operation added.



*/
SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp, int iLineno){






  int addr, i;
  VdbeOp *pOut;
  assert( nOp>0 );
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->nOp + nOp > p->pParse->nOpAlloc && growOpArray(p, nOp) ){
    return 0;
  }
  addr = p->nOp;
  pOut = &p->aOp[addr];
  for(i=0; i<nOp; i++, aOp++, pOut++){
    pOut->opcode = aOp->opcode;
    pOut->p1 = aOp->p1;
    pOut->p2 = aOp->p2;
    assert( aOp->p2>=0 );



    pOut->p3 = aOp->p3;
    pOut->p4type = P4_NOTUSED;
    pOut->p4.p = 0;
    pOut->p5 = 0;
#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
    pOut->zComment = 0;
#endif
................................................................................
#ifdef SQLITE_VDBE_COVERAGE
    pOut->iSrcLine = iLineno+i;
#else
    (void)iLineno;
#endif
#ifdef SQLITE_DEBUG
    if( p->db->flags & SQLITE_VdbeAddopTrace ){
      sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]);
    }
#endif
  }
  p->nOp += nOp;
  return addr;
}

#if defined(SQLITE_ENABLE_STMT_SCANSTATUS)
/*
** Add an entry to the array of counters managed by sqlite3_stmt_scanstatus().
*/
SQLITE_PRIVATE void sqlite3VdbeScanStatus(
................................................................................
SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe *p, u32 addr, int val){
  sqlite3VdbeGetOp(p,addr)->p2 = val;
}
SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe *p, u32 addr, int val){
  sqlite3VdbeGetOp(p,addr)->p3 = val;
}
SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe *p, u8 p5){
  sqlite3VdbeGetOp(p,-1)->p5 = p5;
}

/*
** Change the P2 operand of instruction addr so that it points to
** the address of the next instruction to be coded.
*/
SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe *p, int addr){
................................................................................
** opcodes contained within. If aOp is not NULL it is assumed to contain 
** nOp entries. 
*/
static void vdbeFreeOpArray(sqlite3 *db, Op *aOp, int nOp){
  if( aOp ){
    Op *pOp;
    for(pOp=aOp; pOp<&aOp[nOp]; pOp++){
      freeP4(db, pOp->p4type, pOp->p4.p);
#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
      sqlite3DbFree(db, pOp->zComment);
#endif     
    }
  }
  sqlite3DbFree(db, aOp);
}
................................................................................
  p->pNext = pVdbe->pProgram;
  pVdbe->pProgram = p;
}

/*
** Change the opcode at addr into OP_Noop
*/
SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
  if( addr<p->nOp ){
    VdbeOp *pOp = &p->aOp[addr];
    sqlite3 *db = p->db;
    freeP4(db, pOp->p4type, pOp->p4.p);
    memset(pOp, 0, sizeof(pOp[0]));
    pOp->opcode = OP_Noop;
  }


}

/*
** If the last opcode is "op" and it is not a jump destination,
** then remove it.  Return true if and only if an opcode was removed.
*/
SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe *p, u8 op){
  if( (p->nOp-1)>(p->pParse->iFixedOp) && p->aOp[p->nOp-1].opcode==op ){
    sqlite3VdbeChangeToNoop(p, p->nOp-1);
    return 1;
  }else{
    return 0;
  }
}

/*
** Change the value of the P4 operand for a specific instruction.
................................................................................
** 
** Other values of n (P4_STATIC, P4_COLLSEQ etc.) indicate that zP4 points
** to a string or structure that is guaranteed to exist for the lifetime of
** the Vdbe. In these cases we can just copy the pointer.
**
** If addr<0 then change P4 on the most recently inserted instruction.
*/



















SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
  Op *pOp;
  sqlite3 *db;
  assert( p!=0 );
  db = p->db;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->aOp==0 || db->mallocFailed ){
    if( n!=P4_VTAB ){
      freeP4(db, n, (void*)*(char**)&zP4);
    }
    return;
  }
  assert( p->nOp>0 );
  assert( addr<p->nOp );
  if( addr<0 ){
    addr = p->nOp - 1;
  }
  pOp = &p->aOp[addr];
  assert( pOp->p4type==P4_NOTUSED
       || pOp->p4type==P4_INT32
       || pOp->p4type==P4_KEYINFO );
  freeP4(db, pOp->p4type, pOp->p4.p);
  pOp->p4.p = 0;
  if( n==P4_INT32 ){
    /* Note: this cast is safe, because the origin data point was an int
    ** that was cast to a (const char *). */
    pOp->p4.i = SQLITE_PTR_TO_INT(zP4);
    pOp->p4type = P4_INT32;
  }else if( zP4==0 ){
    pOp->p4.p = 0;
    pOp->p4type = P4_NOTUSED;
  }else if( n==P4_KEYINFO ){
    pOp->p4.p = (void*)zP4;
    pOp->p4type = P4_KEYINFO;
#ifdef SQLITE_ENABLE_CURSOR_HINTS
  }else if( n==P4_EXPR ){
    /* Responsibility for deleting the Expr tree is handed over to the
    ** VDBE by this operation.  The caller should have already invoked
    ** sqlite3ExprDup() or whatever other routine is needed to make a 
    ** private copy of the tree. */
    pOp->p4.pExpr = (Expr*)zP4;
    pOp->p4type = P4_EXPR;
#endif
  }else if( n==P4_VTAB ){
    pOp->p4.p = (void*)zP4;
    pOp->p4type = P4_VTAB;
    sqlite3VtabLock((VTable *)zP4);
    assert( ((VTable *)zP4)->db==p->db );
  }else if( n<0 ){
    pOp->p4.p = (void*)zP4;
    pOp->p4type = (signed char)n;
  }else{
    if( n==0 ) n = sqlite3Strlen30(zP4);
    pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
    pOp->p4type = P4_DYNAMIC;

  }
}

/*
** Set the P4 on the most recently added opcode to the KeyInfo for the
** index given.
*/
................................................................................
#endif /* SQLITE_DEBUG */

#if VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS)
/*
** Translate the P4.pExpr value for an OP_CursorHint opcode into text
** that can be displayed in the P4 column of EXPLAIN output.
*/
static int displayP4Expr(int nTemp, char *zTemp, Expr *pExpr){
  const char *zOp = 0;
  int n;
  switch( pExpr->op ){
    case TK_STRING:
      sqlite3_snprintf(nTemp, zTemp, "%Q", pExpr->u.zToken);
      break;
    case TK_INTEGER:
      sqlite3_snprintf(nTemp, zTemp, "%d", pExpr->u.iValue);
      break;
    case TK_NULL:
      sqlite3_snprintf(nTemp, zTemp, "NULL");

      break;
    case TK_REGISTER: {
      sqlite3_snprintf(nTemp, zTemp, "r[%d]", pExpr->iTable);
      break;
    }
    case TK_COLUMN: {
      if( pExpr->iColumn<0 ){
        sqlite3_snprintf(nTemp, zTemp, "rowid");
      }else{
        sqlite3_snprintf(nTemp, zTemp, "c%d", (int)pExpr->iColumn);
      }
      break;
    }
    case TK_LT:      zOp = "LT";      break;
    case TK_LE:      zOp = "LE";      break;
    case TK_GT:      zOp = "GT";      break;
    case TK_GE:      zOp = "GE";      break;
................................................................................
    case TK_UPLUS:   zOp = "PLUS";    break;
    case TK_BITNOT:  zOp = "BITNOT";  break;
    case TK_NOT:     zOp = "NOT";     break;
    case TK_ISNULL:  zOp = "ISNULL";  break;
    case TK_NOTNULL: zOp = "NOTNULL"; break;

    default:
      sqlite3_snprintf(nTemp, zTemp, "%s", "expr");
      break;
  }

  if( zOp ){
    sqlite3_snprintf(nTemp, zTemp, "%s(", zOp);
    n = sqlite3Strlen30(zTemp);
    n += displayP4Expr(nTemp-n, zTemp+n, pExpr->pLeft);
    if( n<nTemp-1 && pExpr->pRight ){
      zTemp[n++] = ',';

      n += displayP4Expr(nTemp-n, zTemp+n, pExpr->pRight);
    }
    sqlite3_snprintf(nTemp-n, zTemp+n, ")");

  }
  return sqlite3Strlen30(zTemp);
}
#endif /* VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS) */


#if VDBE_DISPLAY_P4
/*
** Compute a string that describes the P4 parameter for an opcode.
** Use zTemp for any required temporary buffer space.
*/
static char *displayP4(Op *pOp, char *zTemp, int nTemp){
  char *zP4 = zTemp;

  assert( nTemp>=20 );

  switch( pOp->p4type ){
    case P4_KEYINFO: {
      int i, j;
      KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
      assert( pKeyInfo->aSortOrder!=0 );
      sqlite3_snprintf(nTemp, zTemp, "k(%d", pKeyInfo->nField);
      i = sqlite3Strlen30(zTemp);
      for(j=0; j<pKeyInfo->nField; j++){
        CollSeq *pColl = pKeyInfo->aColl[j];
        const char *zColl = pColl ? pColl->zName : "nil";
        int n = sqlite3Strlen30(zColl);
        if( n==6 && memcmp(zColl,"BINARY",6)==0 ){
          zColl = "B";
          n = 1;
        }
        if( i+n>nTemp-7 ){
          memcpy(&zTemp[i],",...",4);
          i += 4;
          break;
        }
        zTemp[i++] = ',';
        if( pKeyInfo->aSortOrder[j] ){
          zTemp[i++] = '-';
        }
        memcpy(&zTemp[i], zColl, n+1);
        i += n;
      }
      zTemp[i++] = ')';
      zTemp[i] = 0;
      assert( i<nTemp );

      break;
    }
#ifdef SQLITE_ENABLE_CURSOR_HINTS
    case P4_EXPR: {
      displayP4Expr(nTemp, zTemp, pOp->p4.pExpr);
      break;
    }
#endif
    case P4_COLLSEQ: {
      CollSeq *pColl = pOp->p4.pColl;
      sqlite3_snprintf(nTemp, zTemp, "(%.20s)", pColl->zName);
      break;
    }
    case P4_FUNCDEF: {
      FuncDef *pDef = pOp->p4.pFunc;
      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
      break;
    }
#ifdef SQLITE_DEBUG
    case P4_FUNCCTX: {
      FuncDef *pDef = pOp->p4.pCtx->pFunc;
      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
      break;
    }
#endif
    case P4_INT64: {
      sqlite3_snprintf(nTemp, zTemp, "%lld", *pOp->p4.pI64);
      break;
    }
    case P4_INT32: {
      sqlite3_snprintf(nTemp, zTemp, "%d", pOp->p4.i);
      break;
    }
    case P4_REAL: {
      sqlite3_snprintf(nTemp, zTemp, "%.16g", *pOp->p4.pReal);
      break;
    }
    case P4_MEM: {
      Mem *pMem = pOp->p4.pMem;
      if( pMem->flags & MEM_Str ){
        zP4 = pMem->z;
      }else if( pMem->flags & MEM_Int ){
        sqlite3_snprintf(nTemp, zTemp, "%lld", pMem->u.i);
      }else if( pMem->flags & MEM_Real ){
        sqlite3_snprintf(nTemp, zTemp, "%.16g", pMem->u.r);
      }else if( pMem->flags & MEM_Null ){
        sqlite3_snprintf(nTemp, zTemp, "NULL");
      }else{
        assert( pMem->flags & MEM_Blob );
        zP4 = "(blob)";
      }
      break;
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    case P4_VTAB: {
      sqlite3_vtab *pVtab = pOp->p4.pVtab->pVtab;
      sqlite3_snprintf(nTemp, zTemp, "vtab:%p", pVtab);
      break;
    }
#endif
    case P4_INTARRAY: {
      sqlite3_snprintf(nTemp, zTemp, "intarray");








      break;
    }
    case P4_SUBPROGRAM: {
      sqlite3_snprintf(nTemp, zTemp, "program");
      break;
    }
    case P4_ADVANCE: {
      zTemp[0] = 0;
      break;
    }
    default: {
................................................................................
      zP4 = pOp->p4.z;
      if( zP4==0 ){
        zP4 = zTemp;
        zTemp[0] = 0;
      }
    }
  }

  assert( zP4!=0 );
  return zP4;
}
#endif /* VDBE_DISPLAY_P4 */

/*
** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
................................................................................
  assert( i<(int)sizeof(p->btreeMask)*8 );
  DbMaskSet(p->btreeMask, i);
  if( i!=1 && sqlite3BtreeSharable(p->db->aDb[i].pBt) ){
    DbMaskSet(p->lockMask, i);
  }
}

#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
/*
** If SQLite is compiled to support shared-cache mode and to be threadsafe,
** this routine obtains the mutex associated with each BtShared structure
** that may be accessed by the VM passed as an argument. In doing so it also
** sets the BtShared.db member of each of the BtShared structures, ensuring
** that the correct busy-handler callback is invoked if required.
**
................................................................................
/*
** Release an array of N Mem elements
*/
static void releaseMemArray(Mem *p, int N){
  if( p && N ){
    Mem *pEnd = &p[N];
    sqlite3 *db = p->db;
    u8 malloc_failed = db->mallocFailed;
    if( db->pnBytesFreed ){
      do{
        if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
      }while( (++p)<pEnd );
      return;
    }
    do{
................................................................................
      }else if( p->szMalloc ){
        sqlite3DbFree(db, p->zMalloc);
        p->szMalloc = 0;
      }

      p->flags = MEM_Undefined;
    }while( (++p)<pEnd );
    db->mallocFailed = malloc_failed;
  }
}

/*
** Delete a VdbeFrame object and its contents. VdbeFrame objects are
** allocated by the OP_Program opcode in sqlite3VdbeExec().
*/
................................................................................
  */
  releaseMemArray(pMem, 8);
  p->pResultSet = 0;

  if( p->rc==SQLITE_NOMEM ){
    /* This happens if a malloc() inside a call to sqlite3_column_text() or
    ** sqlite3_column_text16() failed.  */
    db->mallocFailed = 1;
    return SQLITE_ERROR;
  }

  /* When the number of output rows reaches nRow, that means the
  ** listing has finished and sqlite3_step() should return SQLITE_DONE.
  ** nRow is the sum of the number of rows in the main program, plus
  ** the sum of the number of rows in all trigger subprograms encountered
................................................................................
    }
    z[j] = 0;
    sqlite3IoTrace("SQL %s\n", z);
  }
}
#endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */

/*
** Allocate space from a fixed size buffer and return a pointer to
** that space.  If insufficient space is available, return NULL.
**
** The pBuf parameter is the initial value of a pointer which will
** receive the new memory.  pBuf is normally NULL.  If pBuf is not
** NULL, it means that memory space has already been allocated and that
** this routine should not allocate any new memory.  When pBuf is not
** NULL simply return pBuf.  Only allocate new memory space when pBuf
** is NULL.
**
** nByte is the number of bytes of space needed.
**
** pFrom points to *pnFrom bytes of available space.  New space is allocated
** from the end of the pFrom buffer and *pnFrom is decremented.
**
** *pnNeeded is a counter of the number of bytes of space that have failed
** to allocate.  If there is insufficient space in pFrom to satisfy the
** request, then increment *pnNeeded by the amount of the request.
*/
static void *allocSpace(
  void *pBuf,          /* Where return pointer will be stored */
  int nByte,           /* Number of bytes to allocate */
  u8 *pFrom,           /* Memory available for allocation */
  int *pnFrom,         /* IN/OUT: Space available at pFrom */
  int *pnNeeded        /* If allocation cannot be made, increment *pnByte */
){
  assert( EIGHT_BYTE_ALIGNMENT(pFrom) );
  if( pBuf==0 ){
    nByte = ROUND8(nByte);
    if( nByte <= *pnFrom ){
      *pnFrom -= nByte;
      pBuf = &pFrom[*pnFrom];
    }else{
      *pnNeeded += nByte;


    }
  }
  assert( EIGHT_BYTE_ALIGNMENT(pBuf) );
  return pBuf;
}

/*
................................................................................
  for(i=1; i<p->nMem; i++){
    assert( p->aMem[i].db==p->db );
  }
#endif
  p->pc = -1;
  p->rc = SQLITE_OK;
  p->errorAction = OE_Abort;
  p->magic = VDBE_MAGIC_RUN;
  p->nChange = 0;
  p->cacheCtr = 1;
  p->minWriteFileFormat = 255;
  p->iStatement = 0;
  p->nFkConstraint = 0;
#ifdef VDBE_PROFILE
  for(i=0; i<p->nOp; i++){
................................................................................
  sqlite3 *db;                   /* The database connection */
  int nVar;                      /* Number of parameters */
  int nMem;                      /* Number of VM memory registers */
  int nCursor;                   /* Number of cursors required */
  int nArg;                      /* Number of arguments in subprograms */
  int nOnce;                     /* Number of OP_Once instructions */
  int n;                         /* Loop counter */
  int nFree;                     /* Available free space */
  u8 *zCsr;                      /* Memory available for allocation */
  int nByte;                     /* How much extra memory is needed */

  assert( p!=0 );
  assert( p->nOp>0 );
  assert( pParse!=0 );
  assert( p->magic==VDBE_MAGIC_INIT );
  assert( pParse==p->pParse );
  db = p->db;
................................................................................
  nCursor = pParse->nTab;
  nArg = pParse->nMaxArg;
  nOnce = pParse->nOnce;
  if( nOnce==0 ) nOnce = 1; /* Ensure at least one byte in p->aOnceFlag[] */
  
  /* For each cursor required, also allocate a memory cell. Memory
  ** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by
  ** the vdbe program. Instead they are used to allocate space for
  ** VdbeCursor/BtCursor structures. The blob of memory associated with 
  ** cursor 0 is stored in memory cell nMem. Memory cell (nMem-1)
  ** stores the blob of memory associated with cursor 1, etc.
  **
  ** See also: allocateCursor().
  */
  nMem += nCursor;

  /* zCsr will initially point to nFree bytes of unused space at the
  ** end of the opcode array, p->aOp.  The computation of nFree is
  ** conservative - it might be smaller than the true number of free
  ** bytes, but never larger.  nFree must be a multiple of 8 - it is
  ** rounded down if is not.
  */
  n = ROUND8(sizeof(Op)*p->nOp);              /* Bytes of opcode space used */
  zCsr = &((u8*)p->aOp)[n];                   /* Unused opcode space */
  assert( EIGHT_BYTE_ALIGNMENT(zCsr) );
  nFree = ROUNDDOWN8(pParse->szOpAlloc - n);  /* Bytes of unused space */
  assert( nFree>=0 );
  if( nFree>0 ){
    memset(zCsr, 0, nFree);

    assert( EIGHT_BYTE_ALIGNMENT(&zCsr[nFree]) );
  }

  resolveP2Values(p, &nArg);
  p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
  if( pParse->explain && nMem<10 ){
    nMem = 10;
  }
  p->expired = 0;

  /* Memory for registers, parameters, cursor, etc, is allocated in two
  ** passes.  On the first pass, we try to reuse unused space at the 
  ** end of the opcode array.  If we are unable to satisfy all memory
  ** requirements by reusing the opcode array tail, then the second
  ** pass will fill in the rest using a fresh allocation.  
  **
  ** This two-pass approach that reuses as much memory as possible from
  ** the leftover space at the end of the opcode array can significantly
  ** reduce the amount of memory held by a prepared statement.
  */
  do {
    nByte = 0;
    p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), zCsr, &nFree, &nByte);
    p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), zCsr, &nFree, &nByte);
    p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), zCsr, &nFree, &nByte);
    p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), zCsr, &nFree, &nByte);
    p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*),
                          zCsr, &nFree, &nByte);
    p->aOnceFlag = allocSpace(p->aOnceFlag, nOnce, zCsr, &nFree, &nByte);
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
    p->anExec = allocSpace(p->anExec, p->nOp*sizeof(i64), zCsr, &nFree, &nByte);

#endif
    if( nByte ){

      p->pFree = sqlite3DbMallocZero(db, nByte);
    }
    zCsr = p->pFree;
    nFree = nByte;
  }while( nByte && !db->mallocFailed );

  p->nCursor = nCursor;
  p->nOnceFlag = nOnce;
  if( p->aVar ){
    p->nVar = (ynVar)nVar;
    for(n=0; n<nVar; n++){
      p->aVar[n].flags = MEM_Null;
      p->aVar[n].db = db;
    }
  }
  if( p->azVar && pParse->nzVar>0 ){
    p->nzVar = pParse->nzVar;
    memcpy(p->azVar, pParse->azVar, p->nzVar*sizeof(p->azVar[0]));
    memset(pParse->azVar, 0, pParse->nzVar*sizeof(pParse->azVar[0]));
  }
  if( p->aMem ){
    p->aMem--;                      /* aMem[] goes from 1..nMem */
    p->nMem = nMem;                 /*       not from 0..nMem-1 */
    for(n=1; n<=nMem; n++){
      p->aMem[n].flags = MEM_Undefined;
      p->aMem[n].db = db;
    }
................................................................................
  **     SQLITE_INTERRUPT
  **
  ** Then the internal cache might have been left in an inconsistent
  ** state.  We need to rollback the statement transaction, if there is
  ** one, or the complete transaction if there is no statement transaction.
  */

  if( p->db->mallocFailed ){
    p->rc = SQLITE_NOMEM;
  }
  if( p->aOnceFlag ) memset(p->aOnceFlag, 0, p->nOnceFlag);
  closeAllCursors(p);
  if( p->magic!=VDBE_MAGIC_RUN ){
    return SQLITE_OK;
  }
................................................................................
    if( p->bIsReader ) db->nVdbeRead--;
    assert( db->nVdbeActive>=db->nVdbeRead );
    assert( db->nVdbeRead>=db->nVdbeWrite );
    assert( db->nVdbeWrite>=0 );
  }
  p->magic = VDBE_MAGIC_HALT;
  checkActiveVdbeCnt(db);
  if( p->db->mallocFailed ){
    p->rc = SQLITE_NOMEM;
  }

  /* If the auto-commit flag is set to true, then any locks that were held
  ** by connection db have now been released. Call sqlite3ConnectionUnlocked() 
  ** to invoke any required unlock-notify callbacks.
  */
................................................................................
** This function does not clear the VDBE error code or message, just
** copies them to the database handle.
*/
SQLITE_PRIVATE int sqlite3VdbeTransferError(Vdbe *p){
  sqlite3 *db = p->db;
  int rc = p->rc;
  if( p->zErrMsg ){
    u8 mallocFailed = db->mallocFailed;
    sqlite3BeginBenignMalloc();
    if( db->pErr==0 ) db->pErr = sqlite3ValueNew(db);
    sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
    sqlite3EndBenignMalloc();
    db->mallocFailed = mallocFailed;
    db->errCode = rc;
  }else{
    sqlite3Error(db, rc);
  }
  return rc;
}

................................................................................
  releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
  for(pSub=p->pProgram; pSub; pSub=pNext){
    pNext = pSub->pNext;
    vdbeFreeOpArray(db, pSub->aOp, pSub->nOp);
    sqlite3DbFree(db, pSub);
  }
  for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);

  vdbeFreeOpArray(db, p->aOp, p->nOp);
  sqlite3DbFree(db, p->aColName);
  sqlite3DbFree(db, p->zSql);
  sqlite3DbFree(db, p->pFree);
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  for(i=0; i<p->nScan; i++){
    sqlite3DbFree(db, p->aScan[i].zName);
................................................................................
** MoveTo now.  If no move is pending, check to see if the row has been
** deleted out from under the cursor and if it has, mark the row as
** a NULL row.
**
** If the cursor is already pointing to the correct row and that row has
** not been deleted out from under the cursor, then this routine is a no-op.
*/
SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor *p){

  if( p->eCurType==CURTYPE_BTREE ){
    if( p->deferredMoveto ){






      return handleDeferredMoveto(p);
    }
    if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
      return handleMovedCursor(p);
    }
  }
  return SQLITE_OK;
................................................................................
    sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);
    sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);
    v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);
    n1 = v1==0 ? 0 : c1.n;
    v2 = sqlite3ValueText((sqlite3_value*)&c2, pColl->enc);
    n2 = v2==0 ? 0 : c2.n;
    rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);

    sqlite3VdbeMemRelease(&c1);
    sqlite3VdbeMemRelease(&c2);
    if( (v1==0 || v2==0) && prcErr ) *prcErr = SQLITE_NOMEM;
    return rc;
  }
}

/*
** Compare two blobs.  Return negative, zero, or positive if the first
** is less than, equal to, or greater than the second, respectively.
................................................................................
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored
** in memory obtained from sqlite3DbMalloc).
*/
SQLITE_PRIVATE void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){

  sqlite3 *db = p->db;
  sqlite3DbFree(db, p->zErrMsg);
  p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
  sqlite3_free(pVtab->zErrMsg);
  pVtab->zErrMsg = 0;

}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/************** End of vdbeaux.c *********************************************/
/************** Begin file vdbeapi.c *****************************************/
/*
** 2004 May 26
................................................................................
SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value *pVal){
  return (int)sqlite3VdbeIntValue((Mem*)pVal);
}
SQLITE_API sqlite_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);
}
SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value *pVal){
  return ((Mem*)pVal)->eSubtype;

}
SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value *pVal){
  return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
}
#ifndef SQLITE_OMIT_UTF16
SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value* pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
................................................................................
  sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
}
SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetNull(pCtx->pOut);
}
SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){

  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  pCtx->pOut->eSubtype = eSubtype & 0xff;

}
SQLITE_API void SQLITE_STDCALL sqlite3_result_text(
  sqlite3_context *pCtx, 
  const char *z, 
  int n,
  void (*xDel)(void *)
){
................................................................................

/* An SQLITE_NOMEM error. */
SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetNull(pCtx->pOut);
  pCtx->isError = SQLITE_NOMEM;
  pCtx->fErrorOrAux = 1;
  pCtx->pOut->db->mallocFailed = 1;
}

/*
** This function is called after a transaction has been committed. It 
** invokes callbacks registered with sqlite3_wal_hook() as required.
*/
static int doWalCallbacks(sqlite3 *db){
................................................................................

/*
** Allocate or return the aggregate context for a user function.  A new
** context is allocated on the first call.  Subsequent calls return the
** same context that was returned on prior calls.
*/
SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context *p, int nByte){
  assert( p && p->pFunc && p->pFunc->xStep );
  assert( sqlite3_mutex_held(p->pOut->db->mutex) );
  testcase( nByte<0 );
  if( (p->pMem->flags & MEM_Agg)==0 ){
    return createAggContext(p, nByte);
  }else{
    return (void*)p->pMem->z;
  }
................................................................................
**
** This function is deprecated.  Do not use it for new code.  It is
** provide only to avoid breaking legacy code.  New aggregate function
** implementations should keep their own counts within their aggregate
** context.
*/
SQLITE_API int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context *p){
  assert( p && p->pMem && p->pFunc && p->pFunc->xStep );
  return p->pMem->n;
}
#endif

/*
** Return the number of columns in the result set for the statement pStmt.
*/
................................................................................
    sqlite3_mutex_enter(db->mutex);
    assert( db->mallocFailed==0 );
    ret = xFunc(&p->aColName[N]);
     /* A malloc may have failed inside of the xFunc() call. If this
    ** is the case, clear the mallocFailed flag and return NULL.
    */
    if( db->mallocFailed ){
      db->mallocFailed = 0;
      ret = 0;
    }
    sqlite3_mutex_leave(db->mutex);
  }
  return ret;
}

................................................................................
      zRawSql += nToken;
      nextIndex = idx + 1;
      assert( idx>0 && idx<=p->nVar );
      pVar = &p->aVar[idx-1];
      if( pVar->flags & MEM_Null ){
        sqlite3StrAccumAppend(&out, "NULL", 4);
      }else if( pVar->flags & MEM_Int ){
        sqlite3XPrintf(&out, 0, "%lld", pVar->u.i);
      }else if( pVar->flags & MEM_Real ){
        sqlite3XPrintf(&out, 0, "%!.15g", pVar->u.r);
      }else if( pVar->flags & MEM_Str ){
        int nOut;  /* Number of bytes of the string text to include in output */
#ifndef SQLITE_OMIT_UTF16
        u8 enc = ENC(db);
        Mem utf8;
        if( enc!=SQLITE_UTF8 ){
          memset(&utf8, 0, sizeof(utf8));
................................................................................
        nOut = pVar->n;
#ifdef SQLITE_TRACE_SIZE_LIMIT
        if( nOut>SQLITE_TRACE_SIZE_LIMIT ){
          nOut = SQLITE_TRACE_SIZE_LIMIT;
          while( nOut<pVar->n && (pVar->z[nOut]&0xc0)==0x80 ){ nOut++; }
        }
#endif    
        sqlite3XPrintf(&out, 0, "'%.*q'", nOut, pVar->z);
#ifdef SQLITE_TRACE_SIZE_LIMIT
        if( nOut<pVar->n ){
          sqlite3XPrintf(&out, 0, "/*+%d bytes*/", pVar->n-nOut);
        }
#endif
#ifndef SQLITE_OMIT_UTF16
        if( enc!=SQLITE_UTF8 ) sqlite3VdbeMemRelease(&utf8);
#endif
      }else if( pVar->flags & MEM_Zero ){
        sqlite3XPrintf(&out, 0, "zeroblob(%d)", pVar->u.nZero);
      }else{
        int nOut;  /* Number of bytes of the blob to include in output */
        assert( pVar->flags & MEM_Blob );
        sqlite3StrAccumAppend(&out, "x'", 2);
        nOut = pVar->n;
#ifdef SQLITE_TRACE_SIZE_LIMIT
        if( nOut>SQLITE_TRACE_SIZE_LIMIT ) nOut = SQLITE_TRACE_SIZE_LIMIT;
#endif
        for(i=0; i<nOut; i++){
          sqlite3XPrintf(&out, 0, "%02x", pVar->z[i]&0xff);
        }
        sqlite3StrAccumAppend(&out, "'", 1);
#ifdef SQLITE_TRACE_SIZE_LIMIT
        if( nOut<pVar->n ){
          sqlite3XPrintf(&out, 0, "/*+%d bytes*/", pVar->n-nOut);
        }
#endif
      }
    }
  }
  return sqlite3StrAccumFinish(&out);
}
................................................................................
  }else if( p->flags & MEM_RowSet ){
    printf(" (rowset)");
  }else{
    char zBuf[200];
    sqlite3VdbeMemPrettyPrint(p, zBuf);
    printf(" %s", zBuf);
  }

}
static void registerTrace(int iReg, Mem *p){
  printf("REG[%d] = ", iReg);
  memTracePrint(p);
  printf("\n");
}
#endif
................................................................................
  Vdbe *p                    /* The VDBE */
){
  Op *aOp = p->aOp;          /* Copy of p->aOp */
  Op *pOp = aOp;             /* Current operation */
#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
  Op *pOrigOp;               /* Value of pOp at the top of the loop */
#endif



  int rc = SQLITE_OK;        /* Value to return */
  sqlite3 *db = p->db;       /* The database */
  u8 resetSchemaOnFault = 0; /* Reset schema after an error if positive */
  u8 encoding = ENC(db);     /* The database encoding */
  int iCompare = 0;          /* Result of last OP_Compare operation */
  unsigned nVmStep = 0;      /* Number of virtual machine steps */
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
................................................................................
    }
    if( p->db->flags & SQLITE_VdbeTrace )  printf("VDBE Trace:\n");
  }
  sqlite3EndBenignMalloc();
#endif
  for(pOp=&aOp[p->pc]; rc==SQLITE_OK; pOp++){
    assert( pOp>=aOp && pOp<&aOp[p->nOp]);
    if( db->mallocFailed ) goto no_mem;
#ifdef VDBE_PROFILE
    start = sqlite3Hwtime();
#endif
    nVmStep++;
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
    if( p->anExec ) p->anExec[(int)(pOp-aOp)]++;
#endif
................................................................................
  sqlite3_context *pCtx;

  assert( pOp->p4type==P4_FUNCDEF );
  n = pOp->p5;
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem-p->nCursor)+1) );
  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
  pCtx = sqlite3DbMallocRaw(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
  if( pCtx==0 ) goto no_mem;
  pCtx->pOut = 0;
  pCtx->pFunc = pOp->p4.pFunc;
  pCtx->iOp = (int)(pOp - aOp);
  pCtx->pVdbe = p;
  pCtx->argc = n;
  pOp->p4type = P4_FUNCCTX;
................................................................................
    assert( memIsValid(pCtx->argv[i]) );
    REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);
  }
#endif
  MemSetTypeFlag(pCtx->pOut, MEM_Null);
  pCtx->fErrorOrAux = 0;
  db->lastRowid = lastRowid;
  (*pCtx->pFunc->xFunc)(pCtx, pCtx->argc, pCtx->argv); /* IMP: R-24505-23230 */
  lastRowid = db->lastRowid;  /* Remember rowid changes made by xFunc */

  /* If the function returned an error, throw an exception */
  if( pCtx->fErrorOrAux ){
    if( pCtx->isError ){
      sqlite3VdbeError(p, "%s", sqlite3_value_text(pCtx->pOut));
      rc = pCtx->isError;
    }
................................................................................
**
** Set the permutation used by the OP_Compare operator to be the array
** of integers in P4.
**
** The permutation is only valid until the next OP_Compare that has
** the OPFLAG_PERMUTE bit set in P5. Typically the OP_Permutation should 
** occur immediately prior to the OP_Compare.



*/
case OP_Permutation: {
  assert( pOp->p4type==P4_INTARRAY );
  assert( pOp->p4.ai );
  aPermute = pOp->p4.ai;
  break;
}

/* Opcode: Compare P1 P2 P3 P4 P5
** Synopsis: r[P1@P3] <-> r[P2@P3]
**
** Compare two vectors of registers in reg(P1)..reg(P1+P3-1) (call this
................................................................................
  const u8 *zData;   /* Part of the record being decoded */
  const u8 *zHdr;    /* Next unparsed byte of the header */
  const u8 *zEndHdr; /* Pointer to first byte after the header */
  u32 offset;        /* Offset into the data */
  u64 offset64;      /* 64-bit offset */
  u32 avail;         /* Number of bytes of available data */
  u32 t;             /* A type code from the record header */
  u16 fx;            /* pDest->flags value */
  Mem *pReg;         /* PseudoTable input register */


  p2 = pOp->p2;




  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  pDest = &aMem[pOp->p3];
  memAboutToChange(p, pDest);
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( p2<pC->nField );
  aOffset = pC->aOffset;
  assert( pC->eCurType!=CURTYPE_VTAB );
  assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );
  assert( pC->eCurType!=CURTYPE_SORTER );
  pCrsr = pC->uc.pCursor;

  /* If the cursor cache is stale, bring it up-to-date */
  rc = sqlite3VdbeCursorMoveto(pC);
  if( rc ) goto abort_due_to_error;
  if( pC->cacheStatus!=p->cacheCtr ){
    if( pC->nullRow ){
      if( pC->eCurType==CURTYPE_PSEUDO ){
        assert( pC->uc.pseudoTableReg>0 );
        pReg = &aMem[pC->uc.pseudoTableReg];
        assert( pReg->flags & MEM_Blob );
................................................................................
  ** all valid.
  */
  assert( p2<pC->nHdrParsed );
  assert( rc==SQLITE_OK );
  assert( sqlite3VdbeCheckMemInvariants(pDest) );
  if( VdbeMemDynamic(pDest) ) sqlite3VdbeMemSetNull(pDest);
  assert( t==pC->aType[p2] );

  if( pC->szRow>=aOffset[p2+1] ){
    /* This is the common case where the desired content fits on the original
    ** page - where the content is not on an overflow page */


    sqlite3VdbeSerialGet(pC->aRow+aOffset[p2], t, pDest);


















  }else{
    /* This branch happens only when content is on overflow pages */
    if( ((pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0
          && ((t>=12 && (t&1)==0) || (pOp->p5 & OPFLAG_TYPEOFARG)!=0))
     || (len = sqlite3VdbeSerialTypeLen(t))==0
    ){
      /* Content is irrelevant for
      **    1. the typeof() function,
      **    2. the length(X) function if X is a blob, and
      **    3. if the content length is zero.
      ** So we might as well use bogus content rather than reading
      ** content from disk.  NULL will work for the value for strings
      ** and blobs and whatever is in the payloadSize64 variable
      ** will work for everything else. */
      sqlite3VdbeSerialGet(t<=13 ? (u8*)&payloadSize64 : 0, t, pDest);
    }else{
      rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, !pC->isTable,
                                   pDest);
      if( rc!=SQLITE_OK ){
        goto op_column_error;
      }
      sqlite3VdbeSerialGet((const u8*)pDest->z, t, pDest);
      pDest->flags &= ~MEM_Ephem;
    }
  }
  pDest->enc = encoding;

op_column_out:
  /* If the column value is an ephemeral string, go ahead and persist
  ** that string in case the cursor moves before the column value is
  ** used.  The following code does the equivalent of Deephemeralize()
  ** but does it faster. */
  if( (pDest->flags & MEM_Ephem)!=0 && pDest->z ){
    fx = pDest->flags & (MEM_Str|MEM_Blob);
    assert( fx!=0 );
    zData = (const u8*)pDest->z;
    len = pDest->n;
    if( sqlite3VdbeMemClearAndResize(pDest, len+2) ) goto no_mem;
    memcpy(pDest->z, zData, len);
    pDest->z[len] = 0;
    pDest->z[len+1] = 0;
    pDest->flags = fx|MEM_Term;
  }

op_column_error:
  UPDATE_MAX_BLOBSIZE(pDest);
  REGISTER_TRACE(pOp->p3, pDest);
  break;
}

/* Opcode: Affinity P1 P2 * P4 *
................................................................................
      assert( db->autoCommit==0 || db->nVTrans==0 );
      rc = sqlite3VtabSavepoint(db, SAVEPOINT_BEGIN,
                                db->nStatement+db->nSavepoint);
      if( rc!=SQLITE_OK ) goto abort_due_to_error;
#endif

      /* Create a new savepoint structure. */
      pNew = sqlite3DbMallocRaw(db, sizeof(Savepoint)+nName+1);
      if( pNew ){
        pNew->zName = (char *)&pNew[1];
        memcpy(pNew->zName, zName, nName+1);
    
        /* If there is no open transaction, then mark this as a special
        ** "transaction savepoint". */
        if( db->autoCommit ){
................................................................................
** there are active writing VMs or active VMs that use shared cache.
**
** This instruction causes the VM to halt.
*/
case OP_AutoCommit: {
  int desiredAutoCommit;
  int iRollback;
  int turnOnAC;

  desiredAutoCommit = pOp->p1;
  iRollback = pOp->p2;
  turnOnAC = desiredAutoCommit && !db->autoCommit;
  assert( desiredAutoCommit==1 || desiredAutoCommit==0 );
  assert( desiredAutoCommit==1 || iRollback==0 );
  assert( db->nVdbeActive>0 );  /* At least this one VM is active */
  assert( p->bIsReader );

  if( turnOnAC && !iRollback && db->nVdbeWrite>0 ){
    /* If this instruction implements a COMMIT and other VMs are writing
    ** return an error indicating that the other VMs must complete first. 
    */
    sqlite3VdbeError(p, "cannot commit transaction - "
                        "SQL statements in progress");
    rc = SQLITE_BUSY;
  }else if( desiredAutoCommit!=db->autoCommit ){
    if( iRollback ){
      assert( desiredAutoCommit==1 );
      sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
      db->autoCommit = 1;








    }else if( (rc = sqlite3VdbeCheckFk(p, 1))!=SQLITE_OK ){
      goto vdbe_return;
    }else{
      db->autoCommit = (u8)desiredAutoCommit;
    }
    if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
      p->pc = (int)(pOp - aOp);
................................................................................
  pOut = out2Prerelease(p, pOp);
  pOut->u.i = iMeta;
  break;
}

/* Opcode: SetCookie P1 P2 P3 * *
**
** Write the content of register P3 (interpreted as an integer)
** into cookie number P2 of database P1.  P2==1 is the schema version.  
** P2==2 is the database format. P2==3 is the recommended pager cache 
** size, and so forth.  P1==0 is the main database file and P1==1 is the 
** database file used to store temporary tables.
**
** A transaction must be started before executing this opcode.
*/
case OP_SetCookie: {       /* in3 */
  Db *pDb;
  assert( pOp->p2<SQLITE_N_BTREE_META );
  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( DbMaskTest(p->btreeMask, pOp->p1) );
  assert( p->readOnly==0 );
  pDb = &db->aDb[pOp->p1];
  assert( pDb->pBt!=0 );
  assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );
  pIn3 = &aMem[pOp->p3];
  sqlite3VdbeMemIntegerify(pIn3);
  /* See note about index shifting on OP_ReadCookie */
  rc = sqlite3BtreeUpdateMeta(pDb->pBt, pOp->p2, (int)pIn3->u.i);
  if( pOp->p2==BTREE_SCHEMA_VERSION ){
    /* When the schema cookie changes, record the new cookie internally */
    pDb->pSchema->schema_cookie = (int)pIn3->u.i;
    db->flags |= SQLITE_InternChanges;
  }else if( pOp->p2==BTREE_FILE_FORMAT ){
    /* Record changes in the file format */
    pDb->pSchema->file_format = (u8)pIn3->u.i;
  }
  if( pOp->p1==1 ){
    /* Invalidate all prepared statements whenever the TEMP database
    ** schema is changed.  Ticket #1644 */
    sqlite3ExpirePreparedStatements(db);
    p->expired = 0;
  }
................................................................................
  assert( nField>=0 );
  testcase( nField==0 );  /* Table with INTEGER PRIMARY KEY and nothing else */
  pCur = allocateCursor(p, pOp->p1, nField, iDb, CURTYPE_BTREE);
  if( pCur==0 ) goto no_mem;
  pCur->nullRow = 1;
  pCur->isOrdered = 1;
  pCur->pgnoRoot = p2;



  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pKeyInfo, pCur->uc.pCursor);
  pCur->pKeyInfo = pKeyInfo;
  /* Set the VdbeCursor.isTable variable. Previous versions of
  ** SQLite used to check if the root-page flags were sane at this point
  ** and report database corruption if they were not, but this check has
  ** since moved into the btree layer.  */  
  pCur->isTable = pOp->p4type!=P4_KEYINFO;
................................................................................
    goto jump_to_p2;
  }else if( eqOnly ){
    assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
    pOp++; /* Skip the OP_IdxLt or OP_IdxGT that follows */
  }
  break;
}

/* Opcode: Seek P1 P2 * * *
** Synopsis:  intkey=r[P2]
**
** P1 is an open table cursor and P2 is a rowid integer.  Arrange
** for P1 to move so that it points to the rowid given by P2.
**
** This is actually a deferred seek.  Nothing actually happens until
** the cursor is used to read a record.  That way, if no reads
** occur, no unnecessary I/O happens.
*/
case OP_Seek: {    /* in2 */
  VdbeCursor *pC;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( pC->uc.pCursor!=0 );
  assert( pC->isTable );
  pC->nullRow = 0;
  pIn2 = &aMem[pOp->p2];
  pC->movetoTarget = sqlite3VdbeIntValue(pIn2);
  pC->deferredMoveto = 1;
  break;
}
  

/* Opcode: Found P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If
** P4>0 then register P3 is the first of P4 registers that form an unpacked
................................................................................
  break;
}

/* Opcode: Delete P1 P2 * P4 P5
**
** Delete the record at which the P1 cursor is currently pointing.
**

** If the P5 parameter is non-zero, the cursor will be left pointing at 
** either the next or the previous record in the table. If it is left 
** pointing at the next record, then the next Next instruction will be a 
** no-op. As a result, in this case it is OK to delete a record from within a

** Next loop. If P5 is zero, then the cursor is left in an undefined state.
**






** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not).
**
** P1 must not be pseudo-table.  It has to be a real table with
** multiple rows.
**
** If P4 is not NULL, then it is the name of the table that P1 is
** pointing to.  The update hook will be invoked, if it exists.
** If P4 is not NULL then the P1 cursor must have been positioned
................................................................................
  ** is being deleted */
  if( pOp->p4.z && pC->isTable && pOp->p5==0 ){
    i64 iKey = 0;
    sqlite3BtreeKeySize(pC->uc.pCursor, &iKey);
    assert( pC->movetoTarget==iKey ); 
  }
#endif
 



















  rc = sqlite3BtreeDelete(pC->uc.pCursor, pOp->p5);
  pC->cacheStatus = CACHE_STALE;

  /* Invoke the update-hook if required. */
  if( rc==SQLITE_OK && hasUpdateCallback ){
    db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE,
                        db->aDb[pC->iDb].zName, pOp->p4.z, pC->movetoTarget);
................................................................................
  pCrsr = pC->uc.pCursor;
  assert( pCrsr!=0 );
  assert( pOp->p5==0 );
  r.pKeyInfo = pC->pKeyInfo;
  r.nField = (u16)pOp->p3;
  r.default_rc = 0;
  r.aMem = &aMem[pOp->p2];
#ifdef SQLITE_DEBUG
  { int i; for(i=0; i<r.nField; i++) assert( memIsValid(&r.aMem[i]) ); }
#endif
  rc = sqlite3BtreeMovetoUnpacked(pCrsr, &r, 0, 0, &res);
  if( rc==SQLITE_OK && res==0 ){
    rc = sqlite3BtreeDelete(pCrsr, 0);
  }
  assert( pC->deferredMoveto==0 );
  pC->cacheStatus = CACHE_STALE;
  break;
}




















/* Opcode: IdxRowid P1 P2 * * *
** Synopsis: r[P2]=rowid
**
** Write into register P2 an integer which is the last entry in the record at
** the end of the index key pointed to by cursor P1.  This integer should be
** the rowid of the table entry to which this index entry points.
**
** See also: Rowid, MakeRecord.
*/
case OP_IdxRowid: {              /* out2 */
  BtCursor *pCrsr;
  VdbeCursor *pC;
  i64 rowid;

  pOut = out2Prerelease(p, pOp);
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  pCrsr = pC->uc.pCursor;
  assert( pCrsr!=0 );
  pOut->flags = MEM_Null;
  assert( pC->isTable==0 );
  assert( pC->deferredMoveto==0 );






  /* sqlite3VbeCursorRestore() can only fail if the record has been deleted
  ** out from under the cursor.  That will never happend for an IdxRowid
  ** opcode, hence the NEVER() arround the check of the return value.
  */
  rc = sqlite3VdbeCursorRestore(pC);

  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;

  if( !pC->nullRow ){
    rowid = 0;  /* Not needed.  Only used to silence a warning. */
    rc = sqlite3VdbeIdxRowid(db, pCrsr, &rowid);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }















    pOut->u.i = rowid;
    pOut->flags = MEM_Int;




  }
  break;
}

/* Opcode: IdxGE P1 P2 P3 P4 P5
** Synopsis: key=r[P3@P4]
**
................................................................................
** See also: Clear
*/
case OP_Destroy: {     /* out2 */
  int iMoved;
  int iDb;

  assert( p->readOnly==0 );

  pOut = out2Prerelease(p, pOp);
  pOut->flags = MEM_Null;
  if( db->nVdbeRead > db->nVDestroy+1 ){
    rc = SQLITE_LOCKED;
    p->errorAction = OE_Abort;
  }else{
    iDb = pOp->p3;
................................................................................
  int nErr;       /* Number of errors reported */
  char *z;        /* Text of the error report */
  Mem *pnErr;     /* Register keeping track of errors remaining */

  assert( p->bIsReader );
  nRoot = pOp->p2;
  assert( nRoot>0 );
  aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(nRoot+1) );
  if( aRoot==0 ) goto no_mem;
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  pnErr = &aMem[pOp->p3];
  assert( (pnErr->flags & MEM_Int)!=0 );
  assert( (pnErr->flags & (MEM_Str|MEM_Blob))==0 );
  pIn1 = &aMem[pOp->p1];
  for(j=0; j<nRoot; j++){
................................................................................
  if( pIn1->u.i>0 ){
    pIn1->u.i -= pOp->p3;
    goto jump_to_p2;
  }
  break;
}

/* Opcode: SetIfNotPos P1 P2 P3 * *
** Synopsis: if r[P1]<=0 then r[P2]=P3
**
** Register P1 must contain an integer.
** If the value of register P1 is not positive (if it is less than 1) then
** set the value of register P2 to be the integer P3.











*/
case OP_SetIfNotPos: {        /* in1, in2 */

  pIn1 = &aMem[pOp->p1];
  assert( pIn1->flags&MEM_Int );
  if( pIn1->u.i<=0 ){

    pOut = out2Prerelease(p, pOp);
    pOut->u.i = pOp->p3;
  }



  break;
}

/* Opcode: IfNotZero P1 P2 P3 * *
** Synopsis: if r[P1]!=0 then r[P1]-=P3, goto P2
**
** Register P1 must contain an integer.  If the content of register P1 is
................................................................................
  sqlite3_context *pCtx;

  assert( pOp->p4type==P4_FUNCDEF );
  n = pOp->p5;
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem-p->nCursor)+1) );
  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
  pCtx = sqlite3DbMallocRaw(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
  if( pCtx==0 ) goto no_mem;
  pCtx->pMem = 0;
  pCtx->pFunc = pOp->p4.pFunc;
  pCtx->iOp = (int)(pOp - aOp);
  pCtx->pVdbe = p;
  pCtx->argc = n;
  pOp->p4type = P4_FUNCCTX;
................................................................................
#endif

  pMem->n++;
  sqlite3VdbeMemInit(&t, db, MEM_Null);
  pCtx->pOut = &t;
  pCtx->fErrorOrAux = 0;
  pCtx->skipFlag = 0;
  (pCtx->pFunc->xStep)(pCtx,pCtx->argc,pCtx->argv); /* IMP: R-24505-23230 */
  if( pCtx->fErrorOrAux ){
    if( pCtx->isError ){
      sqlite3VdbeError(p, "%s", sqlite3_value_text(&t));
      rc = pCtx->isError;
    }
    sqlite3VdbeMemRelease(&t);
  }else{
................................................................................
vdbe_error_halt:
  assert( rc );
  p->rc = rc;
  testcase( sqlite3GlobalConfig.xLog!=0 );
  sqlite3_log(rc, "statement aborts at %d: [%s] %s", 
                   (int)(pOp - aOp), p->zSql, p->zErrMsg);
  sqlite3VdbeHalt(p);
  if( rc==SQLITE_IOERR_NOMEM ) db->mallocFailed = 1;
  rc = SQLITE_ERROR;
  if( resetSchemaOnFault>0 ){
    sqlite3ResetOneSchema(db, resetSchemaOnFault-1);
  }

  /* This is the only way out of this procedure.  We have to
  ** release the mutexes on btrees that were acquired at the
  ** top. */
vdbe_return:
  db->lastRowid = lastRowid;
  testcase( nVmStep>0 );
  p->aCounter[SQLITE_STMTSTATUS_VM_STEP] += (int)nVmStep;
  sqlite3VdbeLeave(p);



  return rc;

  /* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH
  ** is encountered.
  */
too_big:
  sqlite3VdbeError(p, "string or blob too big");
  rc = SQLITE_TOOBIG;
  goto vdbe_error_halt;

  /* Jump to here if a malloc() fails.
  */
no_mem:
  db->mallocFailed = 1;
  sqlite3VdbeError(p, "out of memory");
  rc = SQLITE_NOMEM;
  goto vdbe_error_halt;

  /* Jump to here for any other kind of fatal error.  The "rc" variable
  ** should hold the error number.
  */
................................................................................
  goto vdbe_error_halt;

  /* Jump to here if the sqlite3_interrupt() API sets the interrupt
  ** flag.
  */
abort_due_to_interrupt:
  assert( db->u1.isInterrupted );
  rc = SQLITE_INTERRUPT;
  p->rc = rc;
  sqlite3VdbeError(p, "%s", sqlite3ErrStr(rc));
  goto vdbe_error_halt;
}


/************** End of vdbe.c ************************************************/
................................................................................
  const char *zColumn,    /* The column containing the blob */
  sqlite_int64 iRow,      /* The row containing the glob */
  int flags,              /* True -> read/write access, false -> read-only */
  sqlite3_blob **ppBlob   /* Handle for accessing the blob returned here */
){
  int nAttempt = 0;
  int iCol;               /* Index of zColumn in row-record */

  /* This VDBE program seeks a btree cursor to the identified 
  ** db/table/row entry. The reason for using a vdbe program instead
  ** of writing code to use the b-tree layer directly is that the
  ** vdbe program will take advantage of the various transaction,
  ** locking and error handling infrastructure built into the vdbe.
  **
  ** After seeking the cursor, the vdbe executes an OP_ResultRow.
  ** Code external to the Vdbe then "borrows" the b-tree cursor and
  ** uses it to implement the blob_read(), blob_write() and 
  ** blob_bytes() functions.
  **
  ** The sqlite3_blob_close() function finalizes the vdbe program,
  ** which closes the b-tree cursor and (possibly) commits the 
  ** transaction.
  */
  static const int iLn = VDBE_OFFSET_LINENO(4);
  static const VdbeOpList openBlob[] = {
    /* {OP_Transaction, 0, 0, 0},  // 0: Inserted separately */
    {OP_TableLock, 0, 0, 0},       /* 1: Acquire a read or write lock */
    /* One of the following two instructions is replaced by an OP_Noop. */
    {OP_OpenRead, 0, 0, 0},        /* 2: Open cursor 0 for reading */
    {OP_OpenWrite, 0, 0, 0},       /* 3: Open cursor 0 for read/write */
    {OP_Variable, 1, 1, 1},        /* 4: Push the rowid to the stack */
    {OP_NotExists, 0, 10, 1},      /* 5: Seek the cursor */
    {OP_Column, 0, 0, 1},          /* 6  */
    {OP_ResultRow, 1, 0, 0},       /* 7  */
    {OP_Goto, 0, 4, 0},            /* 8  */
    {OP_Close, 0, 0, 0},           /* 9  */
    {OP_Halt, 0, 0, 0},            /* 10 */
  };

  int rc = SQLITE_OK;
  char *zErr = 0;
  Table *pTab;
  Parse *pParse = 0;
  Incrblob *pBlob = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
................................................................................
        goto blob_open_out;
      }
    }

    pBlob->pStmt = (sqlite3_stmt *)sqlite3VdbeCreate(pParse);
    assert( pBlob->pStmt || db->mallocFailed );
    if( pBlob->pStmt ){




























      Vdbe *v = (Vdbe *)pBlob->pStmt;
      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);



      sqlite3VdbeAddOp4Int(v, OP_Transaction, iDb, flags, 
                           pTab->pSchema->schema_cookie,
                           pTab->pSchema->iGeneration);
      sqlite3VdbeChangeP5(v, 1);     
      sqlite3VdbeAddOpList(v, ArraySize(openBlob), openBlob, iLn);

      /* Make sure a mutex is held on the table to be accessed */
      sqlite3VdbeUsesBtree(v, iDb); 



      /* Configure the OP_TableLock instruction */
#ifdef SQLITE_OMIT_SHARED_CACHE
      sqlite3VdbeChangeToNoop(v, 1);

#else
      sqlite3VdbeChangeP1(v, 1, iDb);

      sqlite3VdbeChangeP2(v, 1, pTab->tnum);
      sqlite3VdbeChangeP3(v, 1, flags);

      sqlite3VdbeChangeP4(v, 1, pTab->zName, P4_TRANSIENT);


#endif

      /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
      ** parameter of the other to pTab->tnum.  */
      sqlite3VdbeChangeToNoop(v, 3 - flags);
      sqlite3VdbeChangeP2(v, 2 + flags, pTab->tnum);
      sqlite3VdbeChangeP3(v, 2 + flags, iDb);




      /* Configure the number of columns. Configure the cursor to
      ** think that the table has one more column than it really
      ** does. An OP_Column to retrieve this imaginary column will
      ** always return an SQL NULL. This is useful because it means
      ** we can invoke OP_Column to fill in the vdbe cursors type 
      ** and offset cache without causing any IO.
      */
      sqlite3VdbeChangeP4(v, 2+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);


      sqlite3VdbeChangeP2(v, 6, pTab->nCol);
      if( !db->mallocFailed ){

        pParse->nVar = 1;
        pParse->nMem = 1;
        pParse->nTab = 1;
        sqlite3VdbeMakeReady(v, pParse);
      }
    }
   
................................................................................
  assert( pFile->iEof>iStart );
  assert( pReadr->aAlloc==0 && pReadr->nAlloc==0 );
  assert( pReadr->aBuffer==0 );
  assert( pReadr->aMap==0 );

  rc = vdbePmaReaderSeek(pTask, pReadr, pFile, iStart);
  if( rc==SQLITE_OK ){
    u64 nByte;                    /* Size of PMA in bytes */
    rc = vdbePmaReadVarint(pReadr, &nByte);
    pReadr->iEof = pReadr->iReadOff + nByte;
    *pnByte += nByte;
  }

  if( rc==SQLITE_OK ){
    rc = vdbePmaReaderNext(pReadr);
................................................................................
  }

  if( pSorter->list.aMemory ){
    int nMin = pSorter->iMemory + nReq;

    if( nMin>pSorter->nMemory ){
      u8 *aNew;

      int nNew = pSorter->nMemory * 2;
      while( nNew < nMin ) nNew = nNew*2;
      if( nNew > pSorter->mxPmaSize ) nNew = pSorter->mxPmaSize;
      if( nNew < nMin ) nNew = nMin;

      aNew = sqlite3Realloc(pSorter->list.aMemory, nNew);
      if( !aNew ) return SQLITE_NOMEM;
      pSorter->list.pList = (SorterRecord*)(
          aNew + ((u8*)pSorter->list.pList - pSorter->list.aMemory)
      );
      pSorter->list.aMemory = aNew;
      pSorter->nMemory = nNew;
    }

    pNew = (SorterRecord*)&pSorter->list.aMemory[pSorter->iMemory];
    pSorter->iMemory += ROUND8(nReq);

    pNew->u.iNext = (int)((u8*)(pSorter->list.pList) - pSorter->list.aMemory);

  }else{
    pNew = (SorterRecord *)sqlite3Malloc(nReq);
    if( pNew==0 ){
      return SQLITE_NOMEM;
    }
    pNew->u.pNext = pSorter->list.pList;
  }
................................................................................
**
**    WRC_Abort         Do no more callbacks.  Unwind the stack and
**                      return the top-level walk call.
**
** The return value from this routine is WRC_Abort to abandon the tree walk
** and WRC_Continue to continue.
*/
SQLITE_PRIVATE int sqlite3WalkExpr(Walker *pWalker, Expr *pExpr){
  int rc;
  if( pExpr==0 ) return WRC_Continue;
  testcase( ExprHasProperty(pExpr, EP_TokenOnly) );
  testcase( ExprHasProperty(pExpr, EP_Reduced) );
  rc = pWalker->xExprCallback(pWalker, pExpr);
  if( rc==WRC_Continue
              && !ExprHasProperty(pExpr,EP_TokenOnly) ){
    if( sqlite3WalkExpr(pWalker, pExpr->pLeft) ) return WRC_Abort;
    if( sqlite3WalkExpr(pWalker, pExpr->pRight) ) return WRC_Abort;
................................................................................
    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
      if( sqlite3WalkSelect(pWalker, pExpr->x.pSelect) ) return WRC_Abort;
    }else{
      if( sqlite3WalkExprList(pWalker, pExpr->x.pList) ) return WRC_Abort;
    }
  }
  return rc & WRC_Abort;



}

/*
** Call sqlite3WalkExpr() for every expression in list p or until
** an abort request is seen.
*/
SQLITE_PRIVATE int sqlite3WalkExprList(Walker *pWalker, ExprList *p){
................................................................................
        pDef = sqlite3FindFunction(pParse->db, zId, nId, -2, enc, 0);
        if( pDef==0 ){
          no_such_func = 1;
        }else{
          wrong_num_args = 1;
        }
      }else{
        is_agg = pDef->xFunc==0;
        if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
          ExprSetProperty(pExpr, EP_Unlikely|EP_Skip);
          if( n==2 ){
            pExpr->iTable = exprProbability(pList->a[1].pExpr);
            if( pExpr->iTable<0 ){
              sqlite3ErrorMsg(pParse,
                "second argument to likelihood() must be a "
................................................................................
      return 1;
    }
    pParse->nHeight += pExpr->nHeight;
  }
#endif
  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg);
  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg);
  memset(&w, 0, sizeof(w));
  w.xExprCallback = resolveExprStep;
  w.xSelectCallback = resolveSelectStep;
  w.pParse = pNC->pParse;


  w.u.pNC = pNC;
  sqlite3WalkExpr(&w, pExpr);
#if SQLITE_MAX_EXPR_DEPTH>0
  pNC->pParse->nHeight -= pExpr->nHeight;
#endif
  if( pNC->nErr>0 || w.pParse->nErr>0 ){
    ExprSetProperty(pExpr, EP_Error);
................................................................................
    }
  }
  return pExpr;
}
SQLITE_PRIVATE Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
  Token s;
  assert( zC!=0 );
  s.z = zC;
  s.n = sqlite3Strlen30(s.z);
  return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
}

/*
** Skip over any TK_COLLATE operators and any unlikely()
** or likelihood() function at the root of an expression.
*/
................................................................................
  const Token *pToken,    /* Token argument.  Might be NULL */
  int dequote             /* True to dequote */
){
  Expr *pNew;
  int nExtra = 0;
  int iValue = 0;


  if( pToken ){
    if( op!=TK_INTEGER || pToken->z==0
          || sqlite3GetInt32(pToken->z, &iValue)==0 ){
      nExtra = pToken->n+1;
      assert( iValue>=0 );
    }
  }
  pNew = sqlite3DbMallocZero(db, sizeof(Expr)+nExtra);
  if( pNew ){

    pNew->op = (u8)op;
    pNew->iAgg = -1;
    if( pToken ){
      if( nExtra==0 ){
        pNew->flags |= EP_IntValue;
        pNew->u.iValue = iValue;
      }else{
................................................................................
      }
      if( x==0 ) x = pExpr->iColumn = (ynVar)(++pParse->nVar);
    }
    if( x>0 ){
      if( x>pParse->nzVar ){
        char **a;
        a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));

        if( a==0 ) return;  /* Error reported through db->mallocFailed */


        pParse->azVar = a;
        memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
        pParse->nzVar = x;
      }
      if( z[0]!='?' || pParse->azVar[x-1]==0 ){
        sqlite3DbFree(db, pParse->azVar[x-1]);
        pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
................................................................................
** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
** if any. Before returning, *pzBuffer is set to the first byte past the
** portion of the buffer copied into by this function.
*/
static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){
  Expr *pNew = 0;                      /* Value to return */
  assert( flags==0 || flags==EXPRDUP_REDUCE );

  if( p ){
    const int isReduced = (flags&EXPRDUP_REDUCE);
    u8 *zAlloc;
    u32 staticFlag = 0;

    assert( pzBuffer==0 || isReduced );

    /* Figure out where to write the new Expr structure. */
    if( pzBuffer ){
      zAlloc = *pzBuffer;
      staticFlag = EP_Static;
    }else{
      zAlloc = sqlite3DbMallocRaw(db, dupedExprSize(p, flags));
    }
    pNew = (Expr *)zAlloc;

    if( pNew ){
      /* Set nNewSize to the size allocated for the structure pointed to
      ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
      ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
................................................................................
  assert( flags==0 || flags==EXPRDUP_REDUCE );
  return exprDup(db, p, flags, 0);
}
SQLITE_PRIVATE ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
  ExprList *pNew;
  struct ExprList_item *pItem, *pOldItem;
  int i;

  if( p==0 ) return 0;
  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
  if( pNew==0 ) return 0;
  pNew->nExpr = i = p->nExpr;
  if( (flags & EXPRDUP_REDUCE)==0 ) for(i=1; i<p->nExpr; i+=i){}
  pNew->a = pItem = sqlite3DbMallocRaw(db,  i*sizeof(p->a[0]) );
  if( pItem==0 ){
    sqlite3DbFree(db, pNew);
    return 0;
  } 
  pOldItem = p->a;
  for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
    Expr *pOldExpr = pOldItem->pExpr;
................................................................................
*/
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
 || !defined(SQLITE_OMIT_SUBQUERY)
SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
  SrcList *pNew;
  int i;
  int nByte;

  if( p==0 ) return 0;
  nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
  pNew = sqlite3DbMallocRaw(db, nByte );
  if( pNew==0 ) return 0;
  pNew->nSrc = pNew->nAlloc = p->nSrc;
  for(i=0; i<p->nSrc; i++){
    struct SrcList_item *pNewItem = &pNew->a[i];
    struct SrcList_item *pOldItem = &p->a[i];
    Table *pTab;
    pNewItem->pSchema = pOldItem->pSchema;
................................................................................
    pNewItem->colUsed = pOldItem->colUsed;
  }
  return pNew;
}
SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
  IdList *pNew;
  int i;

  if( p==0 ) return 0;
  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
  if( pNew==0 ) return 0;
  pNew->nId = p->nId;
  pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
  if( pNew->a==0 ){
    sqlite3DbFree(db, pNew);
    return 0;
  }
  /* Note that because the size of the allocation for p->a[] is not
  ** necessarily a power of two, sqlite3IdListAppend() may not be called
  ** on the duplicate created by this function. */
................................................................................
    pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
    pNewItem->idx = pOldItem->idx;
  }
  return pNew;
}
SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
  Select *pNew, *pPrior;

  if( p==0 ) return 0;
  pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
  if( pNew==0 ) return 0;
  pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
  pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
  pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
  pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
  pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
  pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
................................................................................
*/
SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(
  Parse *pParse,          /* Parsing context */
  ExprList *pList,        /* List to which to append. Might be NULL */
  Expr *pExpr             /* Expression to be appended. Might be NULL */
){
  sqlite3 *db = pParse->db;

  if( pList==0 ){
    pList = sqlite3DbMallocZero(db, sizeof(ExprList) );
    if( pList==0 ){
      goto no_mem;
    }

    pList->a = sqlite3DbMallocRaw(db, sizeof(pList->a[0]));
    if( pList->a==0 ) goto no_mem;
  }else if( (pList->nExpr & (pList->nExpr-1))==0 ){
    struct ExprList_item *a;
    assert( pList->nExpr>0 );
    a = sqlite3DbRealloc(db, pList->a, pList->nExpr*2*sizeof(pList->a[0]));
    if( a==0 ){
      goto no_mem;
................................................................................
        pFarg = pExpr->x.pList;
      }
      nFarg = pFarg ? pFarg->nExpr : 0;
      assert( !ExprHasProperty(pExpr, EP_IntValue) );
      zId = pExpr->u.zToken;
      nId = sqlite3Strlen30(zId);
      pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0);
      if( pDef==0 || pDef->xFunc==0 ){
        sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId);
        break;
      }

      /* Attempt a direct implementation of the built-in COALESCE() and
      ** IFNULL() functions.  This avoids unnecessary evaluation of
      ** arguments past the first non-NULL argument.
................................................................................

exit_rename_table:
  sqlite3SrcListDelete(db, pSrc);
  sqlite3DbFree(db, zName);
  db->flags = savedDbFlags;
}


/*
** Generate code to make sure the file format number is at least minFormat.
** The generated code will increase the file format number if necessary.
*/
SQLITE_PRIVATE void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){
  Vdbe *v;
  v = sqlite3GetVdbe(pParse);
  /* The VDBE should have been allocated before this routine is called.
  ** If that allocation failed, we would have quit before reaching this
  ** point */
  if( ALWAYS(v) ){
    int r1 = sqlite3GetTempReg(pParse);
    int r2 = sqlite3GetTempReg(pParse);
    int addr1;
    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT);
    sqlite3VdbeUsesBtree(v, iDb);
    sqlite3VdbeAddOp2(v, OP_Integer, minFormat, r2);
    addr1 = sqlite3VdbeAddOp3(v, OP_Ge, r2, 0, r1);
    sqlite3VdbeChangeP5(v, SQLITE_NOTNULL); VdbeCoverage(v);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, r2);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3ReleaseTempReg(pParse, r1);
    sqlite3ReleaseTempReg(pParse, r2);
  }
}

/*
** This function is called after an "ALTER TABLE ... ADD" statement
** has been parsed. Argument pColDef contains the text of the new
** column definition.
**
** The Table structure pParse->pNewTable was extended to include
** the new column during parsing.
................................................................................
  int iDb;                  /* Database number */
  const char *zDb;          /* Database name */
  const char *zTab;         /* Table name */
  char *zCol;               /* Null-terminated column definition */
  Column *pCol;             /* The new column */
  Expr *pDflt;              /* Default value for the new column */
  sqlite3 *db;              /* The database connection; */


  db = pParse->db;
  if( pParse->nErr || db->mallocFailed ) return;

  pNew = pParse->pNewTable;
  assert( pNew );

  assert( sqlite3BtreeHoldsAllMutexes(db) );
  iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
  zDb = db->aDb[iDb].zName;
  zTab = &pNew->zName[16];  /* Skip the "sqlite_altertab_" prefix on the name */
................................................................................
  */
  if( pDflt ){
    sqlite3_value *pVal = 0;
    int rc;
    rc = sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_BLOB, &pVal);
    assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
    if( rc!=SQLITE_OK ){
      db->mallocFailed = 1;
      return;
    }
    if( !pVal ){
      sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
      return;
    }
    sqlite3ValueFree(pVal);
................................................................................
      zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
      zTab
    );
    sqlite3DbFree(db, zCol);
    db->flags = savedDbFlags;
  }

  /* If the default value of the new column is NULL, then set the file
  ** format to 2. If the default value of the new column is not NULL,
  ** the file format becomes 3.




  */
  sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);



  /* Reload the schema of the modified table. */
  reloadTableSchema(pParse, pTab, pTab->zName);
}

/*
** This function is called by the parser after the table-name in
................................................................................
  pNew->nCol = pTab->nCol;
  assert( pNew->nCol>0 );
  nAlloc = (((pNew->nCol-1)/8)*8)+8;
  assert( nAlloc>=pNew->nCol && nAlloc%8==0 && nAlloc-pNew->nCol<8 );
  pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc);
  pNew->zName = sqlite3MPrintf(db, "sqlite_altertab_%s", pTab->zName);
  if( !pNew->aCol || !pNew->zName ){
    db->mallocFailed = 1;
    goto exit_begin_add_column;
  }
  memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);
  for(i=0; i<pNew->nCol; i++){
    Column *pCol = &pNew->aCol[i];
    pCol->zName = sqlite3DbStrDup(db, pCol->zName);
    pCol->zColl = 0;
................................................................................

/* Initialize the BLOB value of a ROWID
*/
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
static void sampleSetRowid(sqlite3 *db, Stat4Sample *p, int n, const u8 *pData){
  assert( db!=0 );
  if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid);
  p->u.aRowid = sqlite3DbMallocRaw(db, n);
  if( p->u.aRowid ){
    p->nRowid = n;
    memcpy(p->u.aRowid, pData, n);
  }else{
    p->nRowid = 0;
  }
}
................................................................................
  sqlite3_result_blob(context, p, sizeof(*p), stat4Destructor);
}
static const FuncDef statInitFuncdef = {
  2+IsStat34,      /* nArg */
  SQLITE_UTF8,     /* funcFlags */
  0,               /* pUserData */
  0,               /* pNext */
  statInit,        /* xFunc */
  0,               /* xStep */
  0,               /* xFinalize */
  "stat_init",     /* zName */
  0,               /* pHash */
  0                /* pDestructor */
};

#ifdef SQLITE_ENABLE_STAT4
................................................................................
#endif
}
static const FuncDef statPushFuncdef = {
  2+IsStat34,      /* nArg */
  SQLITE_UTF8,     /* funcFlags */
  0,               /* pUserData */
  0,               /* pNext */
  statPush,        /* xFunc */
  0,               /* xStep */
  0,               /* xFinalize */
  "stat_push",     /* zName */
  0,               /* pHash */
  0                /* pDestructor */
};

#define STAT_GET_STAT1 0          /* "stat" column of stat1 table */
................................................................................
#endif
}
static const FuncDef statGetFuncdef = {
  1+IsStat34,      /* nArg */
  SQLITE_UTF8,     /* funcFlags */
  0,               /* pUserData */
  0,               /* pNext */
  statGet,         /* xFunc */
  0,               /* xStep */
  0,               /* xFinalize */
  "stat_get",      /* zName */
  0,               /* pHash */
  0                /* pDestructor */
};

static void callStatGet(Vdbe *v, int regStat4, int iParam, int regOut){
................................................................................
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  sqlite3VdbeAddOp2(v, OP_Integer, iParam, regStat4+1);
#elif SQLITE_DEBUG
  assert( iParam==STAT_GET_STAT1 );
#else
  UNUSED_PARAMETER( iParam );
#endif
  sqlite3VdbeAddOp3(v, OP_Function0, 0, regStat4, regOut);
  sqlite3VdbeChangeP4(v, -1, (char*)&statGetFuncdef, P4_FUNCDEF);
  sqlite3VdbeChangeP5(v, 1 + IsStat34);
}

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
................................................................................
    ** The third argument is only used for STAT3 and STAT4
    */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat4+3);
#endif
    sqlite3VdbeAddOp2(v, OP_Integer, nCol, regStat4+1);
    sqlite3VdbeAddOp2(v, OP_Integer, pIdx->nKeyCol, regStat4+2);
    sqlite3VdbeAddOp3(v, OP_Function0, 0, regStat4+1, regStat4);
    sqlite3VdbeChangeP4(v, -1, (char*)&statInitFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 2+IsStat34);

    /* Implementation of the following:
    **
    **   Rewind csr
    **   if eof(csr) goto end_of_scan;
    **   regChng = 0
................................................................................
    VdbeCoverage(v);
    sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);
    addrNextRow = sqlite3VdbeCurrentAddr(v);

    if( nColTest>0 ){
      int endDistinctTest = sqlite3VdbeMakeLabel(v);
      int *aGotoChng;               /* Array of jump instruction addresses */
      aGotoChng = sqlite3DbMallocRaw(db, sizeof(int)*nColTest);
      if( aGotoChng==0 ) continue;

      /*
      **  next_row:
      **   regChng = 0
      **   if( idx(0) != regPrev(0) ) goto chng_addr_0
      **   regChng = 1
................................................................................
        VdbeComment((v, "%s", pTab->aCol[pPk->aiColumn[j]].zName));
      }
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regKey, pPk->nKeyCol, regRowid);
      sqlite3ReleaseTempRange(pParse, regKey, pPk->nKeyCol);
    }
#endif
    assert( regChng==(regStat4+1) );
    sqlite3VdbeAddOp3(v, OP_Function0, 1, regStat4, regTemp);
    sqlite3VdbeChangeP4(v, -1, (char*)&statPushFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 2+IsStat34);
    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v);

    /* Add the entry to the stat1 table. */
    callStatGet(v, regStat4, STAT_GET_STAT1, regStat1);
    assert( "BBB"[0]==SQLITE_AFF_TEXT );
    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "BBB", 0);
................................................................................
    int nCol = pIndex->nKeyCol+1;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    /* Index.aiRowEst may already be set here if there are duplicate 
    ** sqlite_stat1 entries for this index. In that case just clobber
    ** the old data with the new instead of allocating a new array.  */
    if( pIndex->aiRowEst==0 ){
      pIndex->aiRowEst = (tRowcnt*)sqlite3MallocZero(sizeof(tRowcnt) * nCol);
      if( pIndex->aiRowEst==0 ) pInfo->db->mallocFailed = 1;
    }
    aiRowEst = pIndex->aiRowEst;
#endif
    pIndex->bUnordered = 0;
    decodeIntArray((char*)z, nCol, aiRowEst, pIndex->aiRowLogEst, pIndex);
    if( pIndex->pPartIdxWhere==0 ) pTable->nRowLogEst = pIndex->aiRowLogEst[0];
  }else{
................................................................................
){
  int rc;                       /* Result codes from subroutines */
  sqlite3_stmt *pStmt = 0;      /* An SQL statement being run */
  char *zSql;                   /* Text of the SQL statement */
  Index *pPrevIdx = 0;          /* Previous index in the loop */
  IndexSample *pSample;         /* A slot in pIdx->aSample[] */

  assert( db->lookaside.bEnabled==0 );
  zSql = sqlite3MPrintf(db, zSql1, zDb);
  if( !zSql ){
    return SQLITE_NOMEM;
  }
  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
  sqlite3DbFree(db, zSql);
  if( rc ) return rc;
................................................................................
/*
** Load content from the sqlite_stat4 and sqlite_stat3 tables into 
** the Index.aSample[] arrays of all indices.
*/
static int loadStat4(sqlite3 *db, const char *zDb){
  int rc = SQLITE_OK;             /* Result codes from subroutines */

  assert( db->lookaside.bEnabled==0 );
  if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){
    rc = loadStatTbl(db, 0,
      "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx", 
      "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4",
      zDb
    );
  }
................................................................................
    sqlite3DbFree(db, zSql);
  }


  /* Load the statistics from the sqlite_stat4 table. */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( rc==SQLITE_OK && OptimizationEnabled(db, SQLITE_Stat34) ){
    int lookasideEnabled = db->lookaside.bEnabled;
    db->lookaside.bEnabled = 0;
    rc = loadStat4(db, sInfo.zDatabase);
    db->lookaside.bEnabled = lookasideEnabled;
  }
  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
    Index *pIdx = sqliteHashData(i);
    sqlite3_free(pIdx->aiRowEst);
    pIdx->aiRowEst = 0;
  }
#endif

  if( rc==SQLITE_NOMEM ){
    db->mallocFailed = 1;
  }
  return rc;
}


#endif /* SQLITE_OMIT_ANALYZE */

................................................................................
    }
  }

  /* Allocate the new entry in the db->aDb[] array and initialize the schema
  ** hash tables.
  */
  if( db->aDb==db->aDbStatic ){
    aNew = sqlite3DbMallocRaw(db, sizeof(db->aDb[0])*3 );
    if( aNew==0 ) return;
    memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
  }else{
    aNew = sqlite3DbRealloc(db, db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
    if( aNew==0 ) return;
  }
  db->aDb = aNew;
................................................................................
  /* Open the database file. If the btree is successfully opened, use
  ** it to obtain the database schema. At this point the schema may
  ** or may not be initialized.
  */
  flags = db->openFlags;
  rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
    sqlite3_result_error(context, zErr, -1);
    sqlite3_free(zErr);
    return;
  }
  assert( pVfs );
  flags |= SQLITE_OPEN_MAIN_DB;
  rc = sqlite3BtreeOpen(pVfs, zPath, db, &aNew->pBt, 0, flags);
................................................................................
    }
    sqlite3BtreeEnter(aNew->pBt);
    pPager = sqlite3BtreePager(aNew->pBt);
    sqlite3PagerLockingMode(pPager, db->dfltLockMode);
    sqlite3BtreeSecureDelete(aNew->pBt,
                             sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
    sqlite3BtreeSetPagerFlags(aNew->pBt, 3 | (db->flags & PAGER_FLAGS_MASK));

#endif
    sqlite3BtreeLeave(aNew->pBt);
  }
  aNew->safety_level = 3;
  aNew->zName = sqlite3DbStrDup(db, zName);
  if( rc==SQLITE_OK && aNew->zName==0 ){
    rc = SQLITE_NOMEM;
................................................................................
      sqlite3BtreeClose(db->aDb[iDb].pBt);
      db->aDb[iDb].pBt = 0;
      db->aDb[iDb].pSchema = 0;
    }
    sqlite3ResetAllSchemasOfConnection(db);
    db->nDb = iDb;
    if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
      db->mallocFailed = 1;
      sqlite3DbFree(db, zErrDyn);
      zErrDyn = sqlite3MPrintf(db, "out of memory");
    }else if( zErrDyn==0 ){
      zErrDyn = sqlite3MPrintf(db, "unable to open database: %s", zFile);
    }
    goto attach_error;
  }
................................................................................
  regArgs = sqlite3GetTempRange(pParse, 4);
  sqlite3ExprCode(pParse, pFilename, regArgs);
  sqlite3ExprCode(pParse, pDbname, regArgs+1);
  sqlite3ExprCode(pParse, pKey, regArgs+2);

  assert( v || db->mallocFailed );
  if( v ){
    sqlite3VdbeAddOp3(v, OP_Function0, 0, regArgs+3-pFunc->nArg, regArgs+3);

    assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg );
    sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg));
    sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF);

    /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
    ** statement only). For DETACH, set it to false (expire all existing
    ** statements).
    */
    sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH));
  }
  
................................................................................
*/
SQLITE_PRIVATE void sqlite3Detach(Parse *pParse, Expr *pDbname){
  static const FuncDef detach_func = {
    1,                /* nArg */
    SQLITE_UTF8,      /* funcFlags */
    0,                /* pUserData */
    0,                /* pNext */
    detachFunc,       /* xFunc */
    0,                /* xStep */
    0,                /* xFinalize */
    "sqlite_detach",  /* zName */
    0,                /* pHash */
    0                 /* pDestructor */
  };
  codeAttach(pParse, SQLITE_DETACH, &detach_func, pDbname, 0, 0, pDbname);
}
................................................................................
*/
SQLITE_PRIVATE void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *pKey){
  static const FuncDef attach_func = {
    3,                /* nArg */
    SQLITE_UTF8,      /* funcFlags */
    0,                /* pUserData */
    0,                /* pNext */
    attachFunc,       /* xFunc */
    0,                /* xStep */
    0,                /* xFinalize */
    "sqlite_attach",  /* zName */
    0,                /* pHash */
    0                 /* pDestructor */
  };
  codeAttach(pParse, SQLITE_ATTACH, &attach_func, p, p, pDbname, pKey);
}
................................................................................
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
*/
/* #include "sqliteInt.h" */

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
*/
SQLITE_PRIVATE void sqlite3BeginParse(Parse *pParse, int explainFlag){
  pParse->explain = (u8)explainFlag;
  pParse->nVar = 0;
}

#ifndef SQLITE_OMIT_SHARED_CACHE
/*
** The TableLock structure is only used by the sqlite3TableLock() and
** codeTableLocks() functions.
*/
struct TableLock {
  int iDb;             /* The database containing the table to be locked */
................................................................................
    p = &pToplevel->aTableLock[pToplevel->nTableLock++];
    p->iDb = iDb;
    p->iTab = iTab;
    p->isWriteLock = isWriteLock;
    p->zName = zName;
  }else{
    pToplevel->nTableLock = 0;
    pToplevel->db->mallocFailed = 1;
  }
}

/*
** Code an OP_TableLock instruction for each table locked by the
** statement (configured by calls to sqlite3TableLock()).
*/
................................................................................
  if( v && pParse->nErr==0 && !db->mallocFailed ){
    assert( pParse->iCacheLevel==0 );  /* Disables and re-enables match */
    /* A minimum of one cursor is required if autoincrement is used
    *  See ticket [a696379c1f08866] */
    if( pParse->pAinc!=0 && pParse->nTab==0 ) pParse->nTab = 1;
    sqlite3VdbeMakeReady(v, pParse);
    pParse->rc = SQLITE_DONE;
    pParse->colNamesSet = 0;
  }else{
    pParse->rc = SQLITE_ERROR;
  }




  pParse->nTab = 0;
  pParse->nMem = 0;
  pParse->nSet = 0;
  pParse->nVar = 0;
  DbMaskZero(pParse->cookieMask);

}

/*
** Run the parser and code generator recursively in order to generate
** code for the SQL statement given onto the end of the pParse context
** currently under construction.  When the parser is run recursively
** this way, the final OP_Halt is not appended and other initialization
................................................................................
      continue;
    }
    if( j<i ){
      db->aDb[j] = db->aDb[i];
    }
    j++;
  }
  memset(&db->aDb[j], 0, (db->nDb-j)*sizeof(db->aDb[j]));
  db->nDb = j;
  if( db->nDb<=2 && db->aDb!=db->aDbStatic ){
    memcpy(db->aDbStatic, db->aDb, 2*sizeof(db->aDb[0]));
    sqlite3DbFree(db, db->aDb);
    db->aDb = db->aDbStatic;
  }
}
................................................................................
  Token *pName1,      /* The "xxx" in the name "xxx.yyy" or "xxx" */
  Token *pName2,      /* The "yyy" in the name "xxx.yyy" */
  Token **pUnqual     /* Write the unqualified object name here */
){
  int iDb;                    /* Database holding the object */
  sqlite3 *db = pParse->db;


  if( ALWAYS(pName2!=0) && pName2->n>0 ){
    if( db->init.busy ) {
      sqlite3ErrorMsg(pParse, "corrupt database");
      return -1;
    }
    *pUnqual = pName2;
    iDb = sqlite3FindDb(db, pName1);
    if( iDb<0 ){
................................................................................
  Table *pTable;
  char *zName = 0; /* The name of the new table */
  sqlite3 *db = pParse->db;
  Vdbe *v;
  int iDb;         /* Database number to create the table in */
  Token *pName;    /* Unqualified name of the table to create */

  /* The table or view name to create is passed to this routine via tokens
  ** pName1 and pName2. If the table name was fully qualified, for example:
  **

  ** CREATE TABLE xxx.yyy (...);
  ** 

  ** Then pName1 is set to "xxx" and pName2 "yyy". On the other hand if
  ** the table name is not fully qualified, i.e.:
  **
  ** CREATE TABLE yyy(...);
  **
  ** Then pName1 is set to "yyy" and pName2 is "".
  **
  ** The call below sets the pName pointer to point at the token (pName1 or
  ** pName2) that stores the unqualified table name. The variable iDb is
  ** set to the index of the database that the table or view is to be
  ** created in.
  */
  iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
  if( iDb<0 ) return;
  if( !OMIT_TEMPDB && isTemp && pName2->n>0 && iDb!=1 ){
    /* If creating a temp table, the name may not be qualified. Unless 
    ** the database name is "temp" anyway.  */
    sqlite3ErrorMsg(pParse, "temporary table name must be unqualified");
    return;
  }
  if( !OMIT_TEMPDB && isTemp ) iDb = 1;


  pParse->sNameToken = *pName;
  zName = sqlite3NameFromToken(db, pName);
  if( zName==0 ) return;
  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
    goto begin_table_error;
  }
  if( db->init.iDb==1 ) isTemp = 1;
#ifndef SQLITE_OMIT_AUTHORIZATION
  assert( (isTemp & 1)==isTemp );


  {
    int code;






    char *zDb = db->aDb[iDb].zName;
    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
      goto begin_table_error;
    }
    if( isView ){
      if( !OMIT_TEMPDB && isTemp ){
        code = SQLITE_CREATE_TEMP_VIEW;
      }else{
        code = SQLITE_CREATE_VIEW;
      }
    }else{
      if( !OMIT_TEMPDB && isTemp ){
        code = SQLITE_CREATE_TEMP_TABLE;
      }else{
        code = SQLITE_CREATE_TABLE;
      }
    }
    if( !isVirtual && sqlite3AuthCheck(pParse, code, zName, 0, zDb) ){

      goto begin_table_error;
    }
  }
#endif

  /* Make sure the new table name does not collide with an existing
  ** index or table name in the same database.  Issue an error message if
................................................................................
      sqlite3ErrorMsg(pParse, "there is already an index named %s", zName);
      goto begin_table_error;
    }
  }

  pTable = sqlite3DbMallocZero(db, sizeof(Table));
  if( pTable==0 ){
    db->mallocFailed = 1;
    pParse->rc = SQLITE_NOMEM;
    pParse->nErr++;
    goto begin_table_error;
  }
  pTable->zName = zName;
  pTable->iPKey = -1;
  pTable->pSchema = db->aDb[iDb].pSchema;
................................................................................
    reg2 = pParse->regRoot = ++pParse->nMem;
    reg3 = ++pParse->nMem;
    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, BTREE_FILE_FORMAT);
    sqlite3VdbeUsesBtree(v, iDb);
    addr1 = sqlite3VdbeAddOp1(v, OP_If, reg3); VdbeCoverage(v);
    fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
                  1 : SQLITE_MAX_FILE_FORMAT;
    sqlite3VdbeAddOp2(v, OP_Integer, fileFormat, reg3);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, reg3);
    sqlite3VdbeAddOp2(v, OP_Integer, ENC(db), reg3);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, reg3);
    sqlite3VdbeJumpHere(v, addr1);

    /* This just creates a place-holder record in the sqlite_master table.
    ** The record created does not contain anything yet.  It will be replaced
    ** by the real entry in code generated at sqlite3EndTable().
    **
    ** The rowid for the new entry is left in register pParse->regRowid.
................................................................................
** This plan is not completely bullet-proof.  It is possible for
** the schema to change multiple times and for the cookie to be
** set back to prior value.  But schema changes are infrequent
** and the probability of hitting the same cookie value is only
** 1 chance in 2^32.  So we're safe enough.
*/
SQLITE_PRIVATE void sqlite3ChangeCookie(Parse *pParse, int iDb){
  int r1 = sqlite3GetTempReg(pParse);
  sqlite3 *db = pParse->db;
  Vdbe *v = pParse->pVdbe;
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  sqlite3VdbeAddOp2(v, OP_Integer, db->aDb[iDb].pSchema->schema_cookie+1, r1);
  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION, r1);
  sqlite3ReleaseTempReg(pParse, r1);

}

/*
** Measure the number of characters needed to output the given
** identifier.  The number returned includes any quotes used
** but does not include the null terminator.
**
................................................................................
    zSep = "\n  ";
    zSep2 = ",\n  ";
    zEnd = "\n)";
  }
  n += 35 + 6*p->nCol;
  zStmt = sqlite3DbMallocRaw(0, n);
  if( zStmt==0 ){
    db->mallocFailed = 1;
    return 0;
  }
  sqlite3_snprintf(n, zStmt, "CREATE TABLE ");
  k = sqlite3Strlen30(zStmt);
  identPut(zStmt, &k, p->zName);
  zStmt[k++] = '(';
  for(pCol=p->aCol, i=0; i<p->nCol; i++, pCol++){
................................................................................

  /* Locate the PRIMARY KEY index.  Or, if this table was originally
  ** an INTEGER PRIMARY KEY table, create a new PRIMARY KEY index. 
  */
  if( pTab->iPKey>=0 ){
    ExprList *pList;
    Token ipkToken;
    ipkToken.z = pTab->aCol[pTab->iPKey].zName;
    ipkToken.n = sqlite3Strlen30(ipkToken.z);
    pList = sqlite3ExprListAppend(pParse, 0, 
                  sqlite3ExprAlloc(db, TK_ID, &ipkToken, 0));
    if( pList==0 ) return;
    pList->a[0].sortOrder = pParse->iPkSortOrder;
    assert( pParse->pNewTable==pTab );
    pPk = sqlite3CreateIndex(pParse, 0, 0, 0, pList, pTab->keyConf, 0, 0, 0, 0);
    if( pPk==0 ) return;
................................................................................
  assert( !db->init.busy || !pSelect );

  /* If the db->init.busy is 1 it means we are reading the SQL off the
  ** "sqlite_master" or "sqlite_temp_master" table on the disk.
  ** So do not write to the disk again.  Extract the root page number
  ** for the table from the db->init.newTnum field.  (The page number
  ** should have been put there by the sqliteOpenCb routine.)



  */
  if( db->init.busy ){
    p->tnum = db->init.newTnum;

  }

  /* Special processing for WITHOUT ROWID Tables */
  if( tabOpts & TF_WithoutRowid ){
    if( (p->tabFlags & TF_Autoincrement) ){
      sqlite3ErrorMsg(pParse,
          "AUTOINCREMENT not allowed on WITHOUT ROWID tables");
................................................................................
      sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);
      sqlite3VdbeChangeP5(v, OPFLAG_P2ISREG);
      pParse->nTab = 2;
      addrTop = sqlite3VdbeCurrentAddr(v) + 1;
      sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
      sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
      sqlite3Select(pParse, pSelect, &dest);
      sqlite3VdbeAddOp1(v, OP_EndCoroutine, regYield);
      sqlite3VdbeJumpHere(v, addrTop - 1);
      if( pParse->nErr ) return;
      pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect);
      if( pSelTab==0 ) return;
      assert( p->aCol==0 );
      p->nCol = pSelTab->nCol;
      p->aCol = pSelTab->aCol;
................................................................................
  if( db->init.busy ){
    Table *pOld;
    Schema *pSchema = p->pSchema;
    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    pOld = sqlite3HashInsert(&pSchema->tblHash, p->zName, p);
    if( pOld ){
      assert( p==pOld );  /* Malloc must have failed inside HashInsert() */
      db->mallocFailed = 1;
      return;
    }
    pParse->pNewTable = 0;
    db->flags |= SQLITE_InternChanges;

#ifndef SQLITE_OMIT_ALTERTABLE
    if( !p->pSelect ){
................................................................................
SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
  Table *pSelTab;   /* A fake table from which we get the result set */
  Select *pSel;     /* Copy of the SELECT that implements the view */
  int nErr = 0;     /* Number of errors encountered */
  int n;            /* Temporarily holds the number of cursors assigned */
  sqlite3 *db = pParse->db;  /* Database connection for malloc errors */
  sqlite3_xauth xAuth;       /* Saved xAuth pointer */
  u8 bEnabledLA;             /* Saved db->lookaside.bEnabled state */

  assert( pTable );

#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( sqlite3VtabCallConnect(pParse, pTable) ){
    return SQLITE_ERROR;
  }
................................................................................
  ** Note that the call to sqlite3ResultSetOfSelect() will expand any
  ** "*" elements in the results set of the view and will assign cursors
  ** to the elements of the FROM clause.  But we do not want these changes
  ** to be permanent.  So the computation is done on a copy of the SELECT
  ** statement that defines the view.
  */
  assert( pTable->pSelect );
  bEnabledLA = db->lookaside.bEnabled;
  if( pTable->pCheck ){
    db->lookaside.bEnabled = 0;
    sqlite3ColumnsFromExprList(pParse, pTable->pCheck, 
                               &pTable->nCol, &pTable->aCol);

  }else{
    pSel = sqlite3SelectDup(db, pTable->pSelect, 0);
    if( pSel ){
      n = pParse->nTab;
      sqlite3SrcListAssignCursors(pParse, pSel->pSrc);
      pTable->nCol = -1;
      db->lookaside.bEnabled = 0;
#ifndef SQLITE_OMIT_AUTHORIZATION
      xAuth = db->xAuth;
      db->xAuth = 0;
      pSelTab = sqlite3ResultSetOfSelect(pParse, pSel);
      db->xAuth = xAuth;
#else
      pSelTab = sqlite3ResultSetOfSelect(pParse, pSel);
#endif

      pParse->nTab = n;
      if( pSelTab ){
        assert( pTable->aCol==0 );
        pTable->nCol = pSelTab->nCol;
        pTable->aCol = pSelTab->aCol;
        pSelTab->nCol = 0;
        pSelTab->aCol = 0;
................................................................................
        nErr++;
      }
      sqlite3SelectDelete(db, pSel);
    } else {
      nErr++;
    }
  }
  db->lookaside.bEnabled = bEnabledLA;
  pTable->pSchema->schemaFlags |= DB_UnresetViews;
#endif /* SQLITE_OMIT_VIEW */
  return nErr;  
}
#endif /* !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE) */

#ifndef SQLITE_OMIT_VIEW
................................................................................
** Also write code to modify the sqlite_master table and internal schema
** if a root-page of another table is moved by the btree-layer whilst
** erasing iTable (this can happen with an auto-vacuum database).
*/ 
static void destroyRootPage(Parse *pParse, int iTable, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  int r1 = sqlite3GetTempReg(pParse);

  sqlite3VdbeAddOp3(v, OP_Destroy, iTable, r1, iDb);
  sqlite3MayAbort(pParse);
#ifndef SQLITE_OMIT_AUTOVACUUM
  /* OP_Destroy stores an in integer r1. If this integer
  ** is non-zero, then it is the root page number of a table moved to
  ** location iTable. The following code modifies the sqlite_master table to
  ** reflect this.
................................................................................
  pFKey->aAction[1] = (u8)((flags >> 8 ) & 0xff);    /* ON UPDATE action */

  assert( sqlite3SchemaMutexHeld(db, 0, p->pSchema) );
  pNextTo = (FKey *)sqlite3HashInsert(&p->pSchema->fkeyHash, 
      pFKey->zTo, (void *)pFKey
  );
  if( pNextTo==pFKey ){
    db->mallocFailed = 1;
    goto fk_end;
  }
  if( pNextTo ){
    assert( pNextTo->pPrevTo==0 );
    pFKey->pNextTo = pNextTo;
    pNextTo->pPrevTo = pFKey;
  }
................................................................................

  /* If pList==0, it means this routine was called to make a primary
  ** key out of the last column added to the table under construction.
  ** So create a fake list to simulate this.
  */
  if( pList==0 ){
    Token prevCol;
    prevCol.z = pTab->aCol[pTab->nCol-1].zName;
    prevCol.n = sqlite3Strlen30(prevCol.z);
    pList = sqlite3ExprListAppend(pParse, 0,
              sqlite3ExprAlloc(db, TK_ID, &prevCol, 0));
    if( pList==0 ) goto exit_create_index;
    assert( pList->nExpr==1 );
    sqlite3ExprListSetSortOrder(pList, sortOrder);
  }else{
    sqlite3ExprListCheckLength(pParse, pList, "index");
................................................................................
  if( db->init.busy ){
    Index *p;
    assert( sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
    p = sqlite3HashInsert(&pIndex->pSchema->idxHash, 
                          pIndex->zName, pIndex);
    if( p ){
      assert( p==pIndex );  /* Malloc must have failed */
      db->mallocFailed = 1;
      goto exit_create_index;
    }
    db->flags |= SQLITE_InternChanges;
    if( pTblName!=0 ){
      pIndex->tnum = db->init.newTnum;
    }
  }
................................................................................
  sqlite3 *db,        /* Connection to notify of malloc failures */
  SrcList *pList,     /* Append to this SrcList. NULL creates a new SrcList */
  Token *pTable,      /* Table to append */
  Token *pDatabase    /* Database of the table */
){
  struct SrcList_item *pItem;
  assert( pDatabase==0 || pTable!=0 );  /* Cannot have C without B */

  if( pList==0 ){
    pList = sqlite3DbMallocZero(db, sizeof(SrcList) );
    if( pList==0 ) return 0;
    pList->nAlloc = 1;

  }
  pList = sqlite3SrcListEnlarge(db, pList, 1, pList->nSrc);
  if( db->mallocFailed ){
    sqlite3SrcListDelete(db, pList);
    return 0;
  }
  pItem = &pList->a[pList->nSrc-1];
................................................................................
      p->a[i].fg.jointype = p->a[i-1].fg.jointype;
    }
    p->a[0].fg.jointype = 0;
  }
}

/*
** Begin a transaction
*/
SQLITE_PRIVATE void sqlite3BeginTransaction(Parse *pParse, int type){
  sqlite3 *db;
  Vdbe *v;
  int i;

  assert( pParse!=0 );
  db = pParse->db;
  assert( db!=0 );
/*  if( db->aDb[0].pBt==0 ) return; */
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ){
    return;
  }
  v = sqlite3GetVdbe(pParse);
  if( !v ) return;
  if( type!=TK_DEFERRED ){
    for(i=0; i<db->nDb; i++){
      sqlite3VdbeAddOp2(v, OP_Transaction, i, (type==TK_EXCLUSIVE)+1);
      sqlite3VdbeUsesBtree(v, i);
    }
  }
  sqlite3VdbeAddOp2(v, OP_AutoCommit, 0, 0);
}

/*
** Commit a transaction
*/
SQLITE_PRIVATE void sqlite3CommitTransaction(Parse *pParse){
  Vdbe *v;

  assert( pParse!=0 );
  assert( pParse->db!=0 );
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "COMMIT", 0, 0) ){
    return;
  }
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, 0);
  }
}

/*
** Rollback a transaction
*/
SQLITE_PRIVATE void sqlite3RollbackTransaction(Parse *pParse){
  Vdbe *v;

  assert( pParse!=0 );
  assert( pParse->db!=0 );
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ){
................................................................................
        "file for storing temporary tables");
      pParse->rc = rc;
      return 1;
    }
    db->aDb[1].pBt = pBt;
    assert( db->aDb[1].pSchema );
    if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1, 0) ){
      db->mallocFailed = 1;
      return 1;
    }
  }
  return 0;
}

/*
................................................................................
){
  Vdbe *v = sqlite3GetVdbe(pParse);
  assert( (errCode&0xff)==SQLITE_CONSTRAINT );
  if( onError==OE_Abort ){
    sqlite3MayAbort(pParse);
  }
  sqlite3VdbeAddOp4(v, OP_Halt, errCode, onError, 0, p4, p4type);
  if( p5Errmsg ) sqlite3VdbeChangeP5(v, p5Errmsg);
}

/*
** Code an OP_Halt due to UNIQUE or PRIMARY KEY constraint violation.
*/
SQLITE_PRIVATE void sqlite3UniqueConstraint(
  Parse *pParse,    /* Parsing context */
................................................................................
  char *zErr;
  int j;
  StrAccum errMsg;
  Table *pTab = pIdx->pTable;

  sqlite3StrAccumInit(&errMsg, pParse->db, 0, 0, 200);
  if( pIdx->aColExpr ){
    sqlite3XPrintf(&errMsg, 0, "index '%q'", pIdx->zName);
  }else{
    for(j=0; j<pIdx->nKeyCol; j++){
      char *zCol;
      assert( pIdx->aiColumn[j]>=0 );
      zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
      if( j ) sqlite3StrAccumAppend(&errMsg, ", ", 2);
      sqlite3XPrintf(&errMsg, 0, "%s.%s", pTab->zName, zCol);
    }
  }
  zErr = sqlite3StrAccumFinish(&errMsg);
  sqlite3HaltConstraint(pParse, 
    IsPrimaryKeyIndex(pIdx) ? SQLITE_CONSTRAINT_PRIMARYKEY 
                            : SQLITE_CONSTRAINT_UNIQUE,
    onError, zErr, P4_DYNAMIC, P5_ConstraintUnique);
................................................................................

  if( pWith ){
    int nByte = sizeof(*pWith) + (sizeof(pWith->a[1]) * pWith->nCte);
    pNew = sqlite3DbRealloc(db, pWith, nByte);
  }else{
    pNew = sqlite3DbMallocZero(db, sizeof(*pWith));
  }
  assert( zName!=0 || pNew==0 );
  assert( db->mallocFailed==0 || pNew==0 );

  if( pNew==0 ){

    sqlite3ExprListDelete(db, pArglist);
    sqlite3SelectDelete(db, pQuery);
    sqlite3DbFree(db, zName);
    pNew = pWith;
  }else{
    pNew->a[pNew->nCte].pSelect = pQuery;
    pNew->a[pNew->nCte].pCols = pArglist;
................................................................................

      /* If a malloc() failure occurred in sqlite3HashInsert(), it will 
      ** return the pColl pointer to be deleted (because it wasn't added
      ** to the hash table).
      */
      assert( pDel==0 || pDel==pColl );
      if( pDel!=0 ){
        db->mallocFailed = 1;
        sqlite3DbFree(db, pDel);
        pColl = 0;
      }
    }
  }
  return pColl;
}
................................................................................
** 1: UTF8/16 conversion required and function takes any number of arguments.
** 2: UTF16 byte order change required and function takes any number of args.
** 3: encoding matches and function takes any number of arguments
** 4: UTF8/16 conversion required - argument count matches exactly
** 5: UTF16 byte order conversion required - argument count matches exactly
** 6: Perfect match:  encoding and argument count match exactly.
**
** If nArg==(-2) then any function with a non-null xStep or xFunc is
** a perfect match and any function with both xStep and xFunc NULL is
** a non-match.
*/
#define FUNC_PERFECT_MATCH 6  /* The score for a perfect match */
static int matchQuality(
  FuncDef *p,     /* The function we are evaluating for match quality */
  int nArg,       /* Desired number of arguments.  (-1)==any */
  u8 enc          /* Desired text encoding */
){
  int match;

  /* nArg of -2 is a special case */
  if( nArg==(-2) ) return (p->xFunc==0 && p->xStep==0) ? 0 : FUNC_PERFECT_MATCH;

  /* Wrong number of arguments means "no match" */
  if( p->nArg!=nArg && p->nArg>=0 ) return 0;

  /* Give a better score to a function with a specific number of arguments
  ** than to function that accepts any number of arguments. */
  if( p->nArg==nArg ){
................................................................................
** NULL if the function does not exist.
**
** If the createFlag argument is true, then a new (blank) FuncDef
** structure is created and liked into the "db" structure if a
** no matching function previously existed.
**
** If nArg is -2, then the first valid function found is returned.  A
** function is valid if either xFunc or xStep is non-zero.  The nArg==(-2)
** case is used to see if zName is a valid function name for some number
** of arguments.  If nArg is -2, then createFlag must be 0.
**
** If createFlag is false, then a function with the required name and
** number of arguments may be returned even if the eTextRep flag does not
** match that requested.
*/
................................................................................
    pBest->nArg = (u16)nArg;
    pBest->funcFlags = enc;
    memcpy(pBest->zName, zName, nName);
    pBest->zName[nName] = 0;
    sqlite3FuncDefInsert(&db->aFunc, pBest);
  }

  if( pBest && (pBest->xStep || pBest->xFunc || createFlag) ){
    return pBest;
  }
  return 0;
}

/*
** Free all resources held by the schema structure. The void* argument points
................................................................................
  Schema * p;
  if( pBt ){
    p = (Schema *)sqlite3BtreeSchema(pBt, sizeof(Schema), sqlite3SchemaClear);
  }else{
    p = (Schema *)sqlite3DbMallocZero(0, sizeof(Schema));
  }
  if( !p ){
    db->mallocFailed = 1;
  }else if ( 0==p->file_format ){
    sqlite3HashInit(&p->tblHash);
    sqlite3HashInit(&p->idxHash);
    sqlite3HashInit(&p->trigHash);
    sqlite3HashInit(&p->fkeyHash);
    p->enc = SQLITE_UTF8;
  }
................................................................................
    }
  
    if( eOnePass!=ONEPASS_OFF ){
      /* For ONEPASS, no need to store the rowid/primary-key. There is only
      ** one, so just keep it in its register(s) and fall through to the
      ** delete code.  */
      nKey = nPk; /* OP_Found will use an unpacked key */
      aToOpen = sqlite3DbMallocRaw(db, nIdx+2);
      if( aToOpen==0 ){
        sqlite3WhereEnd(pWInfo);
        goto delete_from_cleanup;
      }
      memset(aToOpen, 1, nIdx+1);
      aToOpen[nIdx+1] = 0;
      if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
................................................................................
    /* Unless this is a view, open cursors for the table we are 
    ** deleting from and all its indices. If this is a view, then the
    ** only effect this statement has is to fire the INSTEAD OF 
    ** triggers.
    */
    if( !isView ){
      int iAddrOnce = 0;
      u8 p5 = (eOnePass==ONEPASS_OFF ? 0 : OPFLAG_FORDELETE);
      if( eOnePass==ONEPASS_MULTI ){
        iAddrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);
      }
      testcase( IsVirtual(pTab) );
      sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, p5, iTabCur, 
                                 aToOpen, &iDataCur, &iIdxCur);
      assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
      assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
      if( eOnePass==ONEPASS_MULTI ) sqlite3VdbeJumpHere(v, iAddrOnce);
    }
  
    /* Set up a loop over the rowids/primary-keys that were found in the
    ** where-clause loop above.
................................................................................
    sqlite3FkCheck(pParse, pTab, iOld, 0, 0, 0);
  }

  /* Delete the index and table entries. Skip this step if pTab is really
  ** a view (in which case the only effect of the DELETE statement is to
  ** fire the INSTEAD OF triggers).  */ 
  if( pTab->pSelect==0 ){

    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,iIdxNoSeek);
    sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));
    if( count ){
      sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
    }



    if( iIdxNoSeek>=0 ){
      sqlite3VdbeAddOp1(v, OP_Delete, iIdxNoSeek);
    }

    sqlite3VdbeChangeP5(v, eMode==ONEPASS_MULTI);
  }

  /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
  ** handle rows (possibly in other tables) that refer via a foreign key
  ** to the row just deleted. */ 
  sqlite3FkActions(pParse, pTab, 0, iOld, 0, 0);

................................................................................
  sqlite3 *db = sqlite3_context_db_handle(context);

  if( argc>=1 && (zFormat = (const char*)sqlite3_value_text(argv[0]))!=0 ){
    x.nArg = argc-1;
    x.nUsed = 0;
    x.apArg = argv+1;
    sqlite3StrAccumInit(&str, db, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]);

    sqlite3XPrintf(&str, SQLITE_PRINTF_SQLFUNC, zFormat, &x);
    n = str.nChar;
    sqlite3_result_text(context, sqlite3StrAccumFinish(&str), n,
                        SQLITE_DYNAMIC);
  }
}

/*
................................................................................
  sqlite3_result_int(context, sqlite3_total_changes(db));
}

/*
** A structure defining how to do GLOB-style comparisons.
*/
struct compareInfo {
  u8 matchAll;
  u8 matchOne;
  u8 matchSet;
  u8 noCase;
};

/*
** For LIKE and GLOB matching on EBCDIC machines, assume that every
** character is exactly one byte in size.  Also, provde the Utf8Read()
** macro for fast reading of the next character in the common case where
** the next character is ASCII.
................................................................................
**
** This routine is usually quick, but can be N**2 in the worst case.
*/
static int patternCompare(
  const u8 *zPattern,              /* The glob pattern */
  const u8 *zString,               /* The string to compare against the glob */
  const struct compareInfo *pInfo, /* Information about how to do the compare */
  u32 esc                          /* The escape character */
){
  u32 c, c2;                       /* Next pattern and input string chars */
  u32 matchOne = pInfo->matchOne;  /* "?" or "_" */
  u32 matchAll = pInfo->matchAll;  /* "*" or "%" */
  u32 matchOther;                  /* "[" or the escape character */
  u8 noCase = pInfo->noCase;       /* True if uppercase==lowercase */
  const u8 *zEscaped = 0;          /* One past the last escaped input char */
  
  /* The GLOB operator does not have an ESCAPE clause.  And LIKE does not
  ** have the matchSet operator.  So we either have to look for one or
  ** the other, never both.  Hence the single variable matchOther is used
  ** to store the one we have to look for.
  */
  matchOther = esc ? esc : pInfo->matchSet;

  while( (c = Utf8Read(zPattern))!=0 ){
    if( c==matchAll ){  /* Match "*" */
      /* Skip over multiple "*" characters in the pattern.  If there
      ** are also "?" characters, skip those as well, but consume a
      ** single character of the input string for each "?" skipped */
      while( (c=Utf8Read(zPattern)) == matchAll || c == matchOne ){
        if( c==matchOne && sqlite3Utf8Read(&zString)==0 ){
          return 0;
        }
      }
      if( c==0 ){
        return 1;   /* "*" at the end of the pattern matches */
      }else if( c==matchOther ){
        if( esc ){
          c = sqlite3Utf8Read(&zPattern);
          if( c==0 ) return 0;
        }else{
          /* "[...]" immediately follows the "*".  We have to do a slow
          ** recursive search in this case, but it is an unusual case. */
          assert( matchOther<0x80 );  /* '[' is a single-byte character */
          while( *zString
                 && patternCompare(&zPattern[-1],zString,pInfo,esc)==0 ){
            SQLITE_SKIP_UTF8(zString);
          }
          return *zString!=0;
        }
      }

      /* At this point variable c contains the first character of the
................................................................................
          cx = sqlite3Toupper(c);
          c = sqlite3Tolower(c);
        }else{
          cx = c;
        }
        while( (c2 = *(zString++))!=0 ){
          if( c2!=c && c2!=cx ) continue;
          if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
        }
      }else{
        while( (c2 = Utf8Read(zString))!=0 ){
          if( c2!=c ) continue;
          if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
        }
      }
      return 0;
    }
    if( c==matchOther ){
      if( esc ){
        c = sqlite3Utf8Read(&zPattern);
        if( c==0 ) return 0;
        zEscaped = zPattern;
      }else{
        u32 prior_c = 0;
        int seen = 0;
        int invert = 0;
................................................................................
  return *zString==0;
}

/*
** The sqlite3_strglob() interface.
*/
SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlobPattern, const char *zString){
  return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, 0)==0;
}

/*
** The sqlite3_strlike() interface.
*/
SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){
  return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc)==0;
................................................................................
*/
static void likeFunc(
  sqlite3_context *context, 
  int argc, 
  sqlite3_value **argv
){
  const unsigned char *zA, *zB;
  u32 escape = 0;
  int nPat;
  sqlite3 *db = sqlite3_context_db_handle(context);


#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  if( sqlite3_value_type(argv[0])==SQLITE_BLOB
   || sqlite3_value_type(argv[1])==SQLITE_BLOB
  ){
#ifdef SQLITE_TEST
    sqlite3_like_count++;
................................................................................
    if( zEsc==0 ) return;
    if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){
      sqlite3_result_error(context, 
          "ESCAPE expression must be a single character", -1);
      return;
    }
    escape = sqlite3Utf8Read(&zEsc);


  }
  if( zA && zB ){
    struct compareInfo *pInfo = sqlite3_user_data(context);
#ifdef SQLITE_TEST
    sqlite3_like_count++;
#endif
    
    sqlite3_result_int(context, patternCompare(zB, zA, pInfo, escape));
  }
}

/*
** Implementation of the NULLIF(x,y) function.  The result is the first
** argument if the arguments are different.  The result is NULL if the
................................................................................
** of the built-in functions above are part of the global function set.
** This routine only deals with those that are not global.
*/
SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
  int rc = sqlite3_overload_function(db, "MATCH", 2);
  assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );
  if( rc==SQLITE_NOMEM ){
    db->mallocFailed = 1;
  }
}

/*
** Set the LIKEOPT flag on the 2-argument function with the given name.
*/
static void setLikeOptFlag(sqlite3 *db, const char *zName, u8 flagVal){
................................................................................
    */
    if( pParent->iPKey>=0 ){
      if( !zKey ) return 0;
      if( !sqlite3StrICmp(pParent->aCol[pParent->iPKey].zName, zKey) ) return 0;
    }
  }else if( paiCol ){
    assert( nCol>1 );
    aiCol = (int *)sqlite3DbMallocRaw(pParse->db, nCol*sizeof(int));
    if( !aiCol ) return 1;
    *paiCol = aiCol;
  }

  for(pIdx=pParent->pIndex; pIdx; pIdx=pIdx->pNext){
    if( pIdx->nKeyCol==nCol && IsUniqueIndex(pIdx) ){ 
      /* pIdx is a UNIQUE index (or a PRIMARY KEY) and has the right number
................................................................................
  Trigger *pTrigger;              /* Trigger definition to return */
  int iAction = (pChanges!=0);    /* 1 for UPDATE, 0 for DELETE */

  action = pFKey->aAction[iAction];
  pTrigger = pFKey->apTrigger[iAction];

  if( action!=OE_None && !pTrigger ){
    u8 enableLookaside;           /* Copy of db->lookaside.bEnabled */
    char const *zFrom;            /* Name of child table */
    int nFrom;                    /* Length in bytes of zFrom */
    Index *pIdx = 0;              /* Parent key index for this FK */
    int *aiCol = 0;               /* child table cols -> parent key cols */
    TriggerStep *pStep = 0;        /* First (only) step of trigger program */
    Expr *pWhere = 0;             /* WHERE clause of trigger step */
    ExprList *pList = 0;          /* Changes list if ON UPDATE CASCADE */
................................................................................
      int iFromCol;               /* Idx of column in child table */
      Expr *pEq;                  /* tFromCol = OLD.tToCol */

      iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
      assert( iFromCol>=0 );
      assert( pIdx!=0 || (pTab->iPKey>=0 && pTab->iPKey<pTab->nCol) );
      assert( pIdx==0 || pIdx->aiColumn[i]>=0 );

      tToCol.z = pTab->aCol[pIdx ? pIdx->aiColumn[i] : pTab->iPKey].zName;
      tFromCol.z = pFKey->pFrom->aCol[iFromCol].zName;

      tToCol.n = sqlite3Strlen30(tToCol.z);
      tFromCol.n = sqlite3Strlen30(tFromCol.z);

      /* Create the expression "OLD.zToCol = zFromCol". It is important
      ** that the "OLD.zToCol" term is on the LHS of the = operator, so
      ** that the affinity and collation sequence associated with the
      ** parent table are used for the comparison. */
      pEq = sqlite3PExpr(pParse, TK_EQ,
          sqlite3PExpr(pParse, TK_DOT, 
................................................................................
          pWhere,
          0, 0, 0, 0, 0, 0
      );
      pWhere = 0;
    }

    /* Disable lookaside memory allocation */
    enableLookaside = db->lookaside.bEnabled;
    db->lookaside.bEnabled = 0;

    pTrigger = (Trigger *)sqlite3DbMallocZero(db, 
        sizeof(Trigger) +         /* struct Trigger */
        sizeof(TriggerStep) +     /* Single step in trigger program */
        nFrom + 1                 /* Space for pStep->zTarget */
    );
    if( pTrigger ){
................................................................................
      if( pWhen ){
        pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0, 0);
        pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
      }
    }

    /* Re-enable the lookaside buffer, if it was disabled earlier. */
    db->lookaside.bEnabled = enableLookaside;

    sqlite3ExprDelete(db, pWhere);
    sqlite3ExprDelete(db, pWhen);
    sqlite3ExprListDelete(db, pList);
    sqlite3SelectDelete(db, pSelect);
    if( db->mallocFailed==1 ){
      fkTriggerDelete(db, pTrigger);
................................................................................
    ** sqliteDeleteIndex() when the Index structure itself is cleaned
    ** up.
    */
    int n;
    Table *pTab = pIdx->pTable;
    pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);
    if( !pIdx->zColAff ){
      db->mallocFailed = 1;
      return 0;
    }
    for(n=0; n<pIdx->nColumn; n++){
      i16 x = pIdx->aiColumn[n];
      if( x>=0 ){
        pIdx->zColAff[n] = pTab->aCol[x].affinity;
      }else if( x==XN_ROWID ){
................................................................................
SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
  int i;
  char *zColAff = pTab->zColAff;
  if( zColAff==0 ){
    sqlite3 *db = sqlite3VdbeDb(v);
    zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);
    if( !zColAff ){
      db->mallocFailed = 1;
      return;
    }

    for(i=0; i<pTab->nCol; i++){
      zColAff[i] = pTab->aCol[i].affinity;
    }
    do{
................................................................................
  if( pTab->tabFlags & TF_Autoincrement ){
    Parse *pToplevel = sqlite3ParseToplevel(pParse);
    AutoincInfo *pInfo;

    pInfo = pToplevel->pAinc;
    while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
    if( pInfo==0 ){
      pInfo = sqlite3DbMallocRaw(pParse->db, sizeof(*pInfo));
      if( pInfo==0 ) return 0;
      pInfo->pNext = pToplevel->pAinc;
      pToplevel->pAinc = pInfo;
      pInfo->pTab = pTab;
      pInfo->iDb = iDb;
      pToplevel->nMem++;                  /* Register to hold name of table */
      pInfo->regCtr = ++pToplevel->nMem;  /* Max rowid register */
................................................................................
** register used by the autoincrement tracker.  
*/
SQLITE_PRIVATE void sqlite3AutoincrementBegin(Parse *pParse){
  AutoincInfo *p;            /* Information about an AUTOINCREMENT */
  sqlite3 *db = pParse->db;  /* The database connection */
  Db *pDb;                   /* Database only autoinc table */
  int memId;                 /* Register holding max rowid */
  int addr;                  /* A VDBE address */
  Vdbe *v = pParse->pVdbe;   /* VDBE under construction */

  /* This routine is never called during trigger-generation.  It is
  ** only called from the top-level */
  assert( pParse->pTriggerTab==0 );
  assert( sqlite3IsToplevel(pParse) );

  assert( v );   /* We failed long ago if this is not so */
  for(p = pParse->pAinc; p; p = p->pNext){














    pDb = &db->aDb[p->iDb];
    memId = p->regCtr;
    assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
    sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
    sqlite3VdbeAddOp3(v, OP_Null, 0, memId, memId+1);
    addr = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeLoadString(v, memId-1, p->pTab->zName);
    sqlite3VdbeAddOp2(v, OP_Rewind, 0, addr+9); VdbeCoverage(v);
    sqlite3VdbeAddOp3(v, OP_Column, 0, 0, memId);
    sqlite3VdbeAddOp3(v, OP_Ne, memId-1, addr+7, memId); VdbeCoverage(v);
    sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
    sqlite3VdbeAddOp2(v, OP_Rowid, 0, memId+1);
    sqlite3VdbeAddOp3(v, OP_Column, 0, 1, memId);
    sqlite3VdbeGoto(v, addr+9);
    sqlite3VdbeAddOp2(v, OP_Next, 0, addr+2); VdbeCoverage(v);
    sqlite3VdbeAddOp2(v, OP_Integer, 0, memId);
    sqlite3VdbeAddOp0(v, OP_Close);
  }
}

/*
** Update the maximum rowid for an autoincrement calculation.
**
** This routine should be called when the top of the stack holds a
** new rowid that is about to be inserted.  If that new rowid is
** larger than the maximum rowid in the memId memory cell, then the
** memory cell is updated.  The stack is unchanged.
*/
static void autoIncStep(Parse *pParse, int memId, int regRowid){
  if( memId>0 ){
    sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, regRowid);
  }
}

................................................................................
/*
** This routine generates the code needed to write autoincrement
** maximum rowid values back into the sqlite_sequence register.
** Every statement that might do an INSERT into an autoincrement
** table (either directly or through triggers) needs to call this
** routine just before the "exit" code.
*/
SQLITE_PRIVATE void sqlite3AutoincrementEnd(Parse *pParse){
  AutoincInfo *p;
  Vdbe *v = pParse->pVdbe;
  sqlite3 *db = pParse->db;

  assert( v );
  for(p = pParse->pAinc; p; p = p->pNext){









    Db *pDb = &db->aDb[p->iDb];
    int addr1;
    int iRec;
    int memId = p->regCtr;

    iRec = sqlite3GetTempReg(pParse);
    assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
    sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
    addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, memId+1); VdbeCoverage(v);
    sqlite3VdbeAddOp2(v, OP_NewRowid, 0, memId+1);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3VdbeAddOp3(v, OP_MakeRecord, memId-1, 2, iRec);
    sqlite3VdbeAddOp3(v, OP_Insert, 0, iRec, memId+1);



    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeAddOp0(v, OP_Close);
    sqlite3ReleaseTempReg(pParse, iRec);
  }



}
#else
/*
** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
** above are all no-ops
*/
# define autoIncBegin(A,B,C) (0)
................................................................................
    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
    sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
    dest.iSdst = bIdListInOrder ? regData : 0;
    dest.nSdst = pTab->nCol;
    rc = sqlite3Select(pParse, pSelect, &dest);
    regFromSelect = dest.iSdst;
    if( rc || db->mallocFailed || pParse->nErr ) goto insert_cleanup;
    sqlite3VdbeAddOp1(v, OP_EndCoroutine, regYield);
    sqlite3VdbeJumpHere(v, addrTop - 1);                       /* label B: */
    assert( pSelect->pEList );
    nColumn = pSelect->pEList->nExpr;

    /* Set useTempTable to TRUE if the result of the SELECT statement
    ** should be written into a temporary table (template 4).  Set to
    ** FALSE if each output row of the SELECT can be written directly into
................................................................................
  }

  /* If this is not a view, open the table and and all indices */
  if( !isView ){
    int nIdx;
    nIdx = sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, -1, 0,
                                      &iDataCur, &iIdxCur);
    aRegIdx = sqlite3DbMallocRaw(db, sizeof(int)*(nIdx+1));
    if( aRegIdx==0 ){
      goto insert_cleanup;
    }
    for(i=0; i<nIdx; i++){
      aRegIdx[i] = ++pParse->nMem;
    }
  }
................................................................................
      sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
      sqlite3MayAbort(pParse);
    }else
#endif
    {
      int isReplace;    /* Set to true if constraints may cause a replace */
      sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
          regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace
      );
      sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
      sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
                               regIns, aRegIdx, 0, appendFlag, isReplace==0);
    }
  }

................................................................................
#endif
#ifdef pTrigger
 #undef pTrigger
#endif
#ifdef tmask
 #undef tmask
#endif






















































/*
** Generate code to do constraint checks prior to an INSERT or an UPDATE
** on table pTab.
**
** The regNewData parameter is the first register in a range that contains
** the data to be inserted or the data after the update.  There will be
................................................................................
  int iDataCur,        /* Canonical data cursor (main table or PK index) */
  int iIdxCur,         /* First index cursor */
  int regNewData,      /* First register in a range holding values to insert */
  int regOldData,      /* Previous content.  0 for INSERTs */
  u8 pkChng,           /* Non-zero if the rowid or PRIMARY KEY changed */
  u8 overrideError,    /* Override onError to this if not OE_Default */
  int ignoreDest,      /* Jump to this label on an OE_Ignore resolution */
  int *pbMayReplace    /* OUT: Set to true if constraint may cause a replace */

){
  Vdbe *v;             /* VDBE under constrution */
  Index *pIdx;         /* Pointer to one of the indices */
  Index *pPk = 0;      /* The PRIMARY KEY index */
  sqlite3 *db;         /* Database connection */
  int i;               /* loop counter */
  int ix;              /* Index loop counter */
................................................................................
  VdbeModuleComment((v, "BEGIN: GenCnstCks(%d,%d,%d,%d,%d)",
                     iDataCur, iIdxCur, regNewData, regOldData, pkChng));

  /* Test all NOT NULL constraints.
  */
  for(i=0; i<nCol; i++){
    if( i==pTab->iPKey ){




      continue;
    }
    onError = pTab->aCol[i].notNull;
    if( onError==OE_None ) continue;
    if( overrideError!=OE_Default ){
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }
    if( onError==OE_Replace && pTab->aCol[i].pDflt==0 ){
      onError = OE_Abort;
................................................................................
  */
#ifndef SQLITE_OMIT_CHECK
  if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
    ExprList *pCheck = pTab->pCheck;
    pParse->ckBase = regNewData+1;
    onError = overrideError!=OE_Default ? overrideError : OE_Abort;
    for(i=0; i<pCheck->nExpr; i++){



      int allOk = sqlite3VdbeMakeLabel(v);
      sqlite3ExprIfTrue(pParse, pCheck->a[i].pExpr, allOk, SQLITE_JUMPIFNULL);
      if( onError==OE_Ignore ){
        sqlite3VdbeGoto(v, ignoreDest);
      }else{
        char *zName = pCheck->a[i].zName;
        if( zName==0 ) zName = pTab->zName;
        if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-15569-63625 */
        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,
................................................................................
    sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdxCur+i, aRegIdx[i]);
    pik_flags = 0;
    if( useSeekResult ) pik_flags = OPFLAG_USESEEKRESULT;
    if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
      assert( pParse->nested==0 );
      pik_flags |= OPFLAG_NCHANGE;
    }
    if( pik_flags )  sqlite3VdbeChangeP5(v, pik_flags);
  }
  if( !HasRowid(pTab) ) return;
  regData = regNewData + 1;
  regRec = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regData, pTab->nCol, regRec);
  if( !bAffinityDone ) sqlite3TableAffinity(v, pTab, 0);
  sqlite3ExprCacheAffinityChange(pParse, regData, pTab->nCol);
................................................................................
** If pTab is a virtual table, then this routine is a no-op and the
** *piDataCur and *piIdxCur values are left uninitialized.
*/
SQLITE_PRIVATE int sqlite3OpenTableAndIndices(
  Parse *pParse,   /* Parsing context */
  Table *pTab,     /* Table to be opened */
  int op,          /* OP_OpenRead or OP_OpenWrite */
  u8 p5,           /* P5 value for OP_Open* instructions */
  int iBase,       /* Use this for the table cursor, if there is one */
  u8 *aToOpen,     /* If not NULL: boolean for each table and index */
  int *piDataCur,  /* Write the database source cursor number here */
  int *piIdxCur    /* Write the first index cursor number here */
){
  int i;
  int iDb;
................................................................................
  }else{
    sqlite3TableLock(pParse, iDb, pTab->tnum, op==OP_OpenWrite, pTab->zName);
  }
  if( piIdxCur ) *piIdxCur = iBase;
  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    int iIdxCur = iBase++;
    assert( pIdx->pSchema==pTab->pSchema );
    if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) && piDataCur ){
      *piDataCur = iIdxCur;
    }
    if( aToOpen==0 || aToOpen[i+1] ){
      sqlite3VdbeAddOp3(v, op, iIdxCur, pIdx->tnum, iDb);
      sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
      sqlite3VdbeChangeP5(v, p5);
      VdbeComment((v, "%s", pIdx->zName));





    }
  }
  if( iBase>pParse->nTab ) pParse->nTab = iBase;
  return i;
}


................................................................................
    }else if( pDest->pIndex==0 ){
      addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
    }else{
      addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
      assert( (pDest->tabFlags & TF_Autoincrement)==0 );
    }
    sqlite3VdbeAddOp2(v, OP_RowData, iSrc, regData);
    sqlite3VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);

    sqlite3VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND);
    sqlite3VdbeChangeP4(v, -1, pDest->zName, 0);
    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1); VdbeCoverage(v);
    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
  }else{
    sqlite3TableLock(pParse, iDbDest, pDest->tnum, 1, pDest->zName);
    sqlite3TableLock(pParse, iDbSrc, pSrc->tnum, 0, pSrc->zName);
  }
................................................................................
          callbackIsInit = 1;
        }
        if( rc==SQLITE_ROW ){
          azVals = &azCols[nCol];
          for(i=0; i<nCol; i++){
            azVals[i] = (char *)sqlite3_column_text(pStmt, i);
            if( !azVals[i] && sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
              db->mallocFailed = 1;
              goto exec_out;
            }
          }
        }
        if( xCallback(pArg, nCol, azVals, azCols) ){
          /* EVIDENCE-OF: R-38229-40159 If the callback function to
          ** sqlite3_exec() returns non-zero, then sqlite3_exec() will
................................................................................
/* Number of pragmas: 60 on by default, 73 total. */

/************** End of pragma.h **********************************************/
/************** Continuing where we left off in pragma.c *********************/

/*
** Interpret the given string as a safety level.  Return 0 for OFF,
** 1 for ON or NORMAL and 2 for FULL.  Return 1 for an empty or 
** unrecognized string argument.  The FULL option is disallowed
** if the omitFull parameter it 1.
**
** Note that the values returned are one less that the values that
** should be passed into sqlite3BtreeSetSafetyLevel().  The is done
** to support legacy SQL code.  The safety level used to be boolean
** and older scripts may have used numbers 0 for OFF and 1 for ON.
*/
static u8 getSafetyLevel(const char *z, int omitFull, u8 dflt){
                             /* 123456789 123456789 */
  static const char zText[] = "onoffalseyestruefull";
  static const u8 iOffset[] = {0, 1, 2, 4, 9, 12, 16};
  static const u8 iLength[] = {2, 2, 3, 5, 3, 4, 4};
  static const u8 iValue[] =  {1, 0, 0, 0, 1, 1, 2};

  int i, n;
  if( sqlite3Isdigit(*z) ){
    return (u8)sqlite3Atoi(z);
  }
  n = sqlite3Strlen30(z);
  for(i=0; i<ArraySize(iLength)-omitFull; i++){
    if( iLength[i]==n && sqlite3StrNICmp(&zText[iOffset[i]],z,n)==0 ){


      return iValue[i];
    }
  }
  return dflt;
}

/*
................................................................................
      { OP_Integer,     0, 2,        0},
      { OP_Subtract,    1, 2,        1},
      { OP_IfPos,       1, 8,        0},
      { OP_Integer,     0, 1,        0},                         /* 6 */
      { OP_Noop,        0, 0,        0},
      { OP_ResultRow,   1, 1,        0},
    };
    int addr;
    sqlite3VdbeUsesBtree(v, iDb);
    if( !zRight ){
      setOneColumnName(v, "cache_size");
      pParse->nMem += 2;

      addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize,iLn);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP1(v, addr+1, iDb);


      sqlite3VdbeChangeP1(v, addr+6, SQLITE_DEFAULT_CACHE_SIZE);
    }else{
      int size = sqlite3AbsInt32(sqlite3Atoi(zRight));
      sqlite3BeginWriteOperation(pParse, 0, iDb);
      sqlite3VdbeAddOp2(v, OP_Integer, size, 1);
      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, 1);
      assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
      pDb->pSchema->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
    }
    break;
  }
#endif /* !SQLITE_OMIT_PAGER_PRAGMAS && !SQLITE_OMIT_DEPRECATED */
................................................................................
      returnSingleInt(v, "page_size", size);
    }else{
      /* Malloc may fail when setting the page-size, as there is an internal
      ** buffer that the pager module resizes using sqlite3_realloc().
      */
      db->nextPagesize = sqlite3Atoi(zRight);
      if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize,-1,0) ){
        db->mallocFailed = 1;
      }
    }
    break;
  }

  /*
  **  PRAGMA [schema.]secure_delete
................................................................................
        */
        static const int iLn = VDBE_OFFSET_LINENO(2);
        static const VdbeOpList setMeta6[] = {
          { OP_Transaction,    0,         1,                 0},    /* 0 */
          { OP_ReadCookie,     0,         1,         BTREE_LARGEST_ROOT_PAGE},
          { OP_If,             1,         0,                 0},    /* 2 */
          { OP_Halt,           SQLITE_OK, OE_Abort,          0},    /* 3 */
          { OP_Integer,        0,         1,                 0},    /* 4 */
          { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 1},    /* 5 */
        };

        int iAddr;

        iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn);
        sqlite3VdbeChangeP1(v, iAddr, iDb);
        sqlite3VdbeChangeP1(v, iAddr+1, iDb);
        sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4);
        sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1);
        sqlite3VdbeChangeP1(v, iAddr+5, iDb);


        sqlite3VdbeUsesBtree(v, iDb);
      }
    }
    break;
  }
#endif

................................................................................
    }
    break;
  }
#endif /* SQLITE_ENABLE_LOCKING_STYLE */      
    
  /*
  **   PRAGMA [schema.]synchronous
  **   PRAGMA [schema.]synchronous=OFF|ON|NORMAL|FULL
  **
  ** Return or set the local value of the synchronous flag.  Changing
  ** the local value does not make changes to the disk file and the
  ** default value will be restored the next time the database is
  ** opened.
  */
  case PragTyp_SYNCHRONOUS: {
................................................................................
  /* Pragma "quick_check" is reduced version of 
  ** integrity_check designed to detect most database corruption
  ** without most of the overhead of a full integrity-check.
  */
  case PragTyp_INTEGRITY_CHECK: {
    int i, j, addr, mxErr;

    /* Code that appears at the end of the integrity check.  If no error
    ** messages have been generated, output OK.  Otherwise output the
    ** error message
    */
    static const int iLn = VDBE_OFFSET_LINENO(2);
    static const VdbeOpList endCode[] = {
      { OP_AddImm,      1, 0,        0},    /* 0 */
      { OP_If,          1, 0,        0},    /* 1 */
      { OP_String8,     0, 3,        0},    /* 2 */
      { OP_ResultRow,   3, 1,        0},
    };

    int isQuick = (sqlite3Tolower(zLeft[0])=='q');

    /* If the PRAGMA command was of the form "PRAGMA <db>.integrity_check",
    ** then iDb is set to the index of the database identified by <db>.
    ** In this case, the integrity of database iDb only is verified by
    ** the VDBE created below.
    **
................................................................................
          sqlite3VdbeLoadString(v, 3, pIdx->zName);
          sqlite3VdbeAddOp3(v, OP_Concat, 3, 2, 7);
          sqlite3VdbeAddOp2(v, OP_ResultRow, 7, 1);
        }
#endif /* SQLITE_OMIT_BTREECOUNT */
      } 
    }










    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn);
    sqlite3VdbeChangeP2(v, addr, -mxErr);
    sqlite3VdbeJumpHere(v, addr+1);
    sqlite3VdbeChangeP4(v, addr+2, "ok", P4_STATIC);






  }
  break;
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_UTF16
  /*
  **   PRAGMA encoding
................................................................................
  case PragTyp_HEADER_VALUE: {
    int iCookie = pPragma->iArg;  /* Which cookie to read or write */
    sqlite3VdbeUsesBtree(v, iDb);
    if( zRight && (pPragma->mPragFlag & PragFlag_ReadOnly)==0 ){
      /* Write the specified cookie value */
      static const VdbeOpList setCookie[] = {
        { OP_Transaction,    0,  1,  0},    /* 0 */
        { OP_Integer,        0,  1,  0},    /* 1 */
        { OP_SetCookie,      0,  0,  1},    /* 2 */
      };
      int addr = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP1(v, addr+1, sqlite3Atoi(zRight));
      sqlite3VdbeChangeP1(v, addr+2, iDb);
      sqlite3VdbeChangeP2(v, addr+2, iCookie);


    }else{
      /* Read the specified cookie value */
      static const VdbeOpList readCookie[] = {
        { OP_Transaction,     0,  0,  0},    /* 0 */
        { OP_ReadCookie,      0,  1,  0},    /* 1 */
        { OP_ResultRow,       1,  1,  0}
      };
      int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie, 0);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP1(v, addr+1, iDb);
      sqlite3VdbeChangeP3(v, addr+1, iCookie);



      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, SQLITE_TRANSIENT);
    }
  }
  break;
#endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */

................................................................................
  const char *zObj,    /* Object being parsed at the point of error */
  const char *zExtra   /* Error information */
){
  sqlite3 *db = pData->db;
  if( !db->mallocFailed && (db->flags & SQLITE_RecoveryMode)==0 ){
    char *z;
    if( zObj==0 ) zObj = "?";
    z = sqlite3_mprintf("malformed database schema (%s)", zObj);
    if( z && zExtra ) z = sqlite3_mprintf("%z - %s", z, zExtra);
    sqlite3DbFree(db, *pData->pzErrMsg);
    *pData->pzErrMsg = z;
    if( z==0 ) db->mallocFailed = 1;
  }
  pData->rc = db->mallocFailed ? SQLITE_NOMEM : SQLITE_CORRUPT_BKPT;
}

/*
** This is the callback routine for the code that initializes the
** database.  See sqlite3Init() below for additional information.
................................................................................
    db->init.iDb = 0;
    if( SQLITE_OK!=rc ){
      if( db->init.orphanTrigger ){
        assert( iDb==1 );
      }else{
        pData->rc = rc;
        if( rc==SQLITE_NOMEM ){
          db->mallocFailed = 1;
        }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){
          corruptSchema(pData, argv[0], sqlite3_errmsg(db));
        }
      }
    }
    sqlite3_finalize(pStmt);
  }else if( argv[0]==0 || (argv[2]!=0 && argv[2][0]!=0) ){
................................................................................
*/
static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
  int rc;
  int i;
#ifndef SQLITE_OMIT_DEPRECATED
  int size;
#endif
  Table *pTab;
  Db *pDb;
  char const *azArg[4];
  int meta[5];
  InitData initData;
  char const *zMasterSchema;
  char const *zMasterName;
  int openedTransaction = 0;

  /*
  ** The master database table has a structure like this
  */
  static const char master_schema[] = 
     "CREATE TABLE sqlite_master(\n"
     "  type text,\n"
     "  name text,\n"
     "  tbl_name text,\n"
     "  rootpage integer,\n"
     "  sql text\n"
     ")"
  ;
#ifndef SQLITE_OMIT_TEMPDB
  static const char temp_master_schema[] = 
     "CREATE TEMP TABLE sqlite_temp_master(\n"
     "  type text,\n"
     "  name text,\n"
     "  tbl_name text,\n"
     "  rootpage integer,\n"
     "  sql text\n"
     ")"
  ;
#else
  #define temp_master_schema 0
#endif

  assert( iDb>=0 && iDb<db->nDb );
  assert( db->aDb[iDb].pSchema );
  assert( sqlite3_mutex_held(db->mutex) );
  assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );

  /* zMasterSchema and zInitScript are set to point at the master schema
  ** and initialisation script appropriate for the database being
  ** initialized. zMasterName is the name of the master table.
  */
  if( !OMIT_TEMPDB && iDb==1 ){
    zMasterSchema = temp_master_schema;
  }else{
    zMasterSchema = master_schema;
  }
  zMasterName = SCHEMA_TABLE(iDb);





  /* Construct the schema tables.  */
  azArg[0] = zMasterName;
  azArg[1] = "1";
  azArg[2] = zMasterSchema;


  azArg[3] = 0;
  initData.db = db;
  initData.iDb = iDb;
  initData.rc = SQLITE_OK;
  initData.pzErrMsg = pzErrMsg;
  sqlite3InitCallback(&initData, 3, (char **)azArg, 0);
  if( initData.rc ){
    rc = initData.rc;
    goto error_out;
  }
  pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
  if( ALWAYS(pTab) ){
    pTab->tabFlags |= TF_Readonly;
  }

  /* Create a cursor to hold the database open
  */
  pDb = &db->aDb[iDb];
  if( pDb->pBt==0 ){
    if( !OMIT_TEMPDB && ALWAYS(iDb==1) ){
      DbSetProperty(db, 1, DB_SchemaLoaded);
................................................................................

  /* Read the schema information out of the schema tables
  */
  assert( db->init.busy );
  {
    char *zSql;
    zSql = sqlite3MPrintf(db, 
        "SELECT name, rootpage, sql FROM '%q'.%s ORDER BY rowid",
        db->aDb[iDb].zName, zMasterName);
#ifndef SQLITE_OMIT_AUTHORIZATION
    {
      sqlite3_xauth xAuth;
      xAuth = db->xAuth;
      db->xAuth = 0;
#endif
................................................................................
  if( openedTransaction ){
    sqlite3BtreeCommit(pDb->pBt);
  }
  sqlite3BtreeLeave(pDb->pBt);

error_out:
  if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
    db->mallocFailed = 1;
  }
  return rc;
}

/*
** Initialize all database files - the main database file, the file
** used to store temporary tables, and any additional database files
................................................................................

    /* If there is not already a read-only (or read-write) transaction opened
    ** on the b-tree database, open one now. If a transaction is opened, it 
    ** will be closed immediately after reading the meta-value. */
    if( !sqlite3BtreeIsInReadTrans(pBt) ){
      rc = sqlite3BtreeBeginTrans(pBt, 0);
      if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
        db->mallocFailed = 1;
      }
      if( rc!=SQLITE_OK ) return;
      openedTransaction = 1;
    }

    /* Read the schema cookie from the database. If it does not match the 
    ** value stored as part of the in-memory schema representation,
................................................................................
** Free all memory allocations in the pParse object
*/
SQLITE_PRIVATE void sqlite3ParserReset(Parse *pParse){
  if( pParse ){
    sqlite3 *db = pParse->db;
    sqlite3DbFree(db, pParse->aLabel);
    sqlite3ExprListDelete(db, pParse->pConstExpr);





  }
}

/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare(
................................................................................
  pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
  if( pParse==0 ){
    rc = SQLITE_NOMEM;
    goto end_prepare;
  }
  pParse->pReprepare = pReprepare;
  assert( ppStmt && *ppStmt==0 );
  assert( !db->mallocFailed );
  assert( sqlite3_mutex_held(db->mutex) );

  /* Check to verify that it is possible to get a read lock on all
  ** database schemas.  The inability to get a read lock indicates that
  ** some other database connection is holding a write-lock, which in
  ** turn means that the other connection has made uncommitted changes
  ** to the schema.
................................................................................
      sqlite3ErrorWithMsg(db, SQLITE_TOOBIG, "statement too long");
      rc = sqlite3ApiExit(db, SQLITE_TOOBIG);
      goto end_prepare;
    }
    zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
    if( zSqlCopy ){
      sqlite3RunParser(pParse, zSqlCopy, &zErrMsg);
      sqlite3DbFree(db, zSqlCopy);
      pParse->zTail = &zSql[pParse->zTail-zSqlCopy];

    }else{
      pParse->zTail = &zSql[nBytes];
    }
  }else{
    sqlite3RunParser(pParse, zSql, &zErrMsg);
  }
  assert( 0==pParse->nQueryLoop );

  if( db->mallocFailed ){
    pParse->rc = SQLITE_NOMEM;
  }
  if( pParse->rc==SQLITE_DONE ) pParse->rc = SQLITE_OK;
  if( pParse->checkSchema ){
    schemaIsValid(pParse);
  }
  if( db->mallocFailed ){
    pParse->rc = SQLITE_NOMEM;
  }
................................................................................
  zSql = sqlite3_sql((sqlite3_stmt *)p);
  assert( zSql!=0 );  /* Reprepare only called for prepare_v2() statements */
  db = sqlite3VdbeDb(p);
  assert( sqlite3_mutex_held(db->mutex) );
  rc = sqlite3LockAndPrepare(db, zSql, -1, 0, p, &pNew, 0);
  if( rc ){
    if( rc==SQLITE_NOMEM ){
      db->mallocFailed = 1;
    }
    assert( pNew==0 );
    return rc;
  }else{
    assert( pNew!=0 );
  }
  sqlite3VdbeSwap((Vdbe*)pNew, p);
................................................................................
  u16 selFlags,         /* Flag parameters, such as SF_Distinct */
  Expr *pLimit,         /* LIMIT value.  NULL means not used */
  Expr *pOffset         /* OFFSET value.  NULL means no offset */
){
  Select *pNew;
  Select standin;
  sqlite3 *db = pParse->db;
  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
  if( pNew==0 ){
    assert( db->mallocFailed );
    pNew = &standin;
    memset(pNew, 0, sizeof(*pNew));
  }
  if( pEList==0 ){
    pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db,TK_ASTERISK,0));
  }
  pNew->pEList = pEList;










  if( pSrc==0 ) pSrc = sqlite3DbMallocZero(db, sizeof(*pSrc));
  pNew->pSrc = pSrc;
  pNew->pWhere = pWhere;
  pNew->pGroupBy = pGroupBy;
  pNew->pHaving = pHaving;
  pNew->pOrderBy = pOrderBy;
  pNew->selFlags = selFlags;
  pNew->op = TK_SELECT;
  pNew->pLimit = pLimit;
  pNew->pOffset = pOffset;

  assert( pOffset==0 || pLimit!=0 || pParse->nErr>0 || db->mallocFailed!=0 );
  pNew->addrOpenEphm[0] = -1;
  pNew->addrOpenEphm[1] = -1;
  if( db->mallocFailed ) {
    clearSelect(db, pNew, pNew!=&standin);
    pNew = 0;
  }else{
    assert( pNew->pSrc!=0 || pParse->nErr>0 );
  }
  assert( pNew!=&standin );
................................................................................
}

/*
** Allocate a KeyInfo object sufficient for an index of N key columns and
** X extra columns.
*/
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N, int X){
  KeyInfo *p = sqlite3DbMallocZero(0, 
                   sizeof(KeyInfo) + (N+X)*(sizeof(CollSeq*)+1));
  if( p ){
    p->aSortOrder = (u8*)&p->aColl[N+X];
    p->nField = (u16)N;
    p->nXField = (u16)X;
    p->enc = ENC(db);
    p->db = db;
    p->nRef = 1;

  }else{
    db->mallocFailed = 1;

  }
  return p;
}

/*
** Deallocate a KeyInfo object
*/
................................................................................
      }
      zName = sqlite3MPrintf(db, "%.*z:%u", nName, zName, ++cnt);
      if( cnt>3 ) sqlite3_randomness(sizeof(cnt), &cnt);
    }
    pCol->zName = zName;
    sqlite3ColumnPropertiesFromName(0, pCol);
    if( zName && sqlite3HashInsert(&ht, zName, pCol)==pCol ){
      db->mallocFailed = 1;
    }
  }
  sqlite3HashClear(&ht);
  if( db->mallocFailed ){
    for(j=0; j<i; j++){
      sqlite3DbFree(db, aCol[j].zName);
    }
................................................................................
  db->flags = savedFlags;
  pTab = sqlite3DbMallocZero(db, sizeof(Table) );
  if( pTab==0 ){
    return 0;
  }
  /* The sqlite3ResultSetOfSelect() is only used n contexts where lookaside
  ** is disabled */
  assert( db->lookaside.bEnabled==0 );
  pTab->nRef = 1;
  pTab->zName = 0;
  pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
  sqlite3ColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
  selectAddColumnTypeAndCollation(pParse, pTab, pSelect);
  pTab->iPKey = -1;
  if( db->mallocFailed ){
................................................................................
    }
    if( p->pOffset ){
      p->iOffset = iOffset = ++pParse->nMem;
      pParse->nMem++;   /* Allocate an extra register for limit+offset */
      sqlite3ExprCode(pParse, p->pOffset, iOffset);
      sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
      VdbeComment((v, "OFFSET counter"));
      sqlite3VdbeAddOp3(v, OP_SetIfNotPos, iOffset, iOffset, 0);
      sqlite3VdbeAddOp3(v, OP_Add, iLimit, iOffset, iOffset+1);
      VdbeComment((v, "LIMIT+OFFSET"));
      sqlite3VdbeAddOp3(v, OP_SetIfNotPos, iLimit, iOffset+1, -1);
    }
  }
}

#ifndef SQLITE_OMIT_COMPOUND_SELECT
/*
** Return the appropriate collating sequence for the iCol-th column of
................................................................................
      p->pPrior = 0;
      p->iLimit = pPrior->iLimit;
      p->iOffset = pPrior->iOffset;
      if( p->iLimit ){
        addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);
        VdbeComment((v, "Jump ahead if LIMIT reached"));
        if( p->iOffset ){
          sqlite3VdbeAddOp3(v, OP_SetIfNotPos, p->iOffset, p->iOffset, 0);
          sqlite3VdbeAddOp3(v, OP_Add, p->iLimit, p->iOffset, p->iOffset+1);
          sqlite3VdbeAddOp3(v, OP_SetIfNotPos, p->iLimit, p->iOffset+1, -1);
        }
      }
      explainSetInteger(iSub2, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, p, &dest);
      testcase( rc!=SQLITE_OK );
      pDelete = p->pPrior;
      p->pPrior = pPrior;
................................................................................
  /* Compute the comparison permutation and keyinfo that is used with
  ** the permutation used to determine if the next
  ** row of results comes from selectA or selectB.  Also add explicit
  ** collations to the ORDER BY clause terms so that when the subqueries
  ** to the right and the left are evaluated, they use the correct
  ** collation.
  */
  aPermute = sqlite3DbMallocRaw(db, sizeof(int)*nOrderBy);
  if( aPermute ){
    struct ExprList_item *pItem;

    for(i=0, pItem=pOrderBy->a; i<nOrderBy; i++, pItem++){
      assert( pItem->u.x.iOrderByCol>0 );
      assert( pItem->u.x.iOrderByCol<=p->pEList->nExpr );
      aPermute[i] = pItem->u.x.iOrderByCol - 1;
    }
    pKeyMerge = multiSelectOrderByKeyInfo(pParse, p, 1);
  }else{
    pKeyMerge = 0;
................................................................................
  */
  addrSelectA = sqlite3VdbeCurrentAddr(v) + 1;
  addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrA, 0, addrSelectA);
  VdbeComment((v, "left SELECT"));
  pPrior->iLimit = regLimitA;
  explainSetInteger(iSub1, pParse->iNextSelectId);
  sqlite3Select(pParse, pPrior, &destA);
  sqlite3VdbeAddOp1(v, OP_EndCoroutine, regAddrA);
  sqlite3VdbeJumpHere(v, addr1);

  /* Generate a coroutine to evaluate the SELECT statement on 
  ** the right - the "B" select
  */
  addrSelectB = sqlite3VdbeCurrentAddr(v) + 1;
  addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrB, 0, addrSelectB);
................................................................................
  savedOffset = p->iOffset;
  p->iLimit = regLimitB;
  p->iOffset = 0;  
  explainSetInteger(iSub2, pParse->iNextSelectId);
  sqlite3Select(pParse, p, &destB);
  p->iLimit = savedLimit;
  p->iOffset = savedOffset;
  sqlite3VdbeAddOp1(v, OP_EndCoroutine, regAddrB);

  /* Generate a subroutine that outputs the current row of the A
  ** select as the next output row of the compound select.
  */
  VdbeNoopComment((v, "Output routine for A"));
  addrOutA = generateOutputSubroutine(pParse,
                 p, &destA, pDest, regOutA,
................................................................................
                zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName);
                zToFree = zColname;
              }
            }else{
              pExpr = pRight;
            }
            pNew = sqlite3ExprListAppend(pParse, pNew, pExpr);
            sColname.z = zColname;
            sColname.n = sqlite3Strlen30(zColname);
            sqlite3ExprListSetName(pParse, pNew, &sColname, 0);
            if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){
              struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];
              if( pSub ){
                pX->zSpan = sqlite3DbStrDup(db, pSub->pEList->a[j].zSpan);
                testcase( pX->zSpan==0 );
              }else{
................................................................................
      pItem->addrFillSub = addrTop;
      sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
      sqlite3Select(pParse, pSub, &dest);
      pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
      pItem->fg.viaCoroutine = 1;
      pItem->regResult = dest.iSdst;
      sqlite3VdbeAddOp1(v, OP_EndCoroutine, pItem->regReturn);
      sqlite3VdbeJumpHere(v, addrTop-1);
      sqlite3ClearTempRegCache(pParse);
    }else{
      /* Generate a subroutine that will fill an ephemeral table with
      ** the content of this subquery.  pItem->addrFillSub will point
      ** to the address of the generated subroutine.  pItem->regReturn
      ** is a register allocated to hold the subroutine return address
................................................................................
          flag = minMaxQuery(&sAggInfo, &pMinMax);
        }
        assert( flag==0 || (pMinMax!=0 && pMinMax->nExpr==1) );

        if( flag ){
          pMinMax = sqlite3ExprListDup(db, pMinMax, 0);
          pDel = pMinMax;

          if( pMinMax && !db->mallocFailed ){
            pMinMax->a[0].sortOrder = flag!=WHERE_ORDERBY_MIN ?1:0;
            pMinMax->a[0].pExpr->op = TK_COLUMN;
          }
        }
  
        /* This case runs if the aggregate has no GROUP BY clause.  The
        ** processing is much simpler since there is only a single row
................................................................................
  zName = pTrig->zName;
  iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
  pTrig->step_list = pStepList;
  while( pStepList ){
    pStepList->pTrig = pTrig;
    pStepList = pStepList->pNext;
  }
  nameToken.z = pTrig->zName;
  nameToken.n = sqlite3Strlen30(nameToken.z);
  sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken);
  if( sqlite3FixTriggerStep(&sFix, pTrig->step_list) 
   || sqlite3FixExpr(&sFix, pTrig->pWhen) 
  ){
    goto triggerfinish_cleanup;
  }

................................................................................

  if( db->init.busy ){
    Trigger *pLink = pTrig;
    Hash *pHash = &db->aDb[iDb].pSchema->trigHash;
    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    pTrig = sqlite3HashInsert(pHash, zName, pTrig);
    if( pTrig ){
      db->mallocFailed = 1;
    }else if( pLink->pSchema==pLink->pTabSchema ){
      Table *pTab;
      pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table);
      assert( pTab!=0 );
      pLink->pNext = pTab->pTrigger;
      pTab->pTrigger = pLink;
    }
................................................................................
  assert( pPrg || pParse->nErr || pParse->db->mallocFailed );

  /* Code the OP_Program opcode in the parent VDBE. P4 of the OP_Program 
  ** is a pointer to the sub-vdbe containing the trigger program.  */
  if( pPrg ){
    int bRecursive = (p->zName && 0==(pParse->db->flags&SQLITE_RecTriggers));

    sqlite3VdbeAddOp3(v, OP_Program, reg, ignoreJump, ++pParse->nMem);
    sqlite3VdbeChangeP4(v, -1, (const char *)pPrg->pProgram, P4_SUBPROGRAM);
    VdbeComment(
        (v, "Call: %s.%s", (p->zName?p->zName:"fkey"), onErrorText(orconf)));

    /* Set the P5 operand of the OP_Program instruction to non-zero if
    ** recursive invocation of this trigger program is disallowed. Recursive
    ** invocation is disallowed if (a) the sub-program is really a trigger,
    ** not a foreign key action, and (b) the flag to enable recursive triggers
................................................................................
    }
    pParse->nTab++;
  }

  /* Allocate space for aXRef[], aRegIdx[], and aToOpen[].  
  ** Initialize aXRef[] and aToOpen[] to their default values.
  */
  aXRef = sqlite3DbMallocRaw(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 );
  if( aXRef==0 ) goto update_cleanup;
  aRegIdx = aXRef+pTab->nCol;
  aToOpen = (u8*)(aRegIdx+nIdx);
  memset(aToOpen, 1, nIdx+1);
  aToOpen[nIdx+1] = 0;
  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;

................................................................................
  if( !isView ){
    int addr1 = 0;        /* Address of jump instruction */
    int bReplace = 0;     /* True if REPLACE conflict resolution might happen */

    /* Do constraint checks. */
    assert( regOldRowid>0 );
    sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
        regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace);


    /* Do FK constraint checks. */
    if( hasFK ){
      sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);
    }

    /* Delete the index entries associated with the current record.  */
................................................................................

  sqlite3_mutex_enter(db->mutex);
  nName = sqlite3Strlen30(zName);
  if( sqlite3HashFind(&db->aModule, zName) ){
    rc = SQLITE_MISUSE_BKPT;
  }else{
    Module *pMod;
    pMod = (Module *)sqlite3DbMallocRaw(db, sizeof(Module) + nName + 1);
    if( pMod ){
      Module *pDel;
      char *zCopy = (char *)(&pMod[1]);
      memcpy(zCopy, zName, nName+1);
      pMod->zName = zCopy;
      pMod->pModule = pModule;
      pMod->pAux = pAux;
      pMod->xDestroy = xDestroy;
      pMod->pEpoTab = 0;
      pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod);
      assert( pDel==0 || pDel==pMod );
      if( pDel ){
        db->mallocFailed = 1;
        sqlite3DbFree(db, pDel);
      }
    }
  }
  rc = sqlite3ApiExit(db, rc);
  if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux);

................................................................................
  else {
    Table *pOld;
    Schema *pSchema = pTab->pSchema;
    const char *zName = pTab->zName;
    assert( sqlite3SchemaMutexHeld(db, 0, pSchema) );
    pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab);
    if( pOld ){
      db->mallocFailed = 1;
      assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */
      return;
    }
    pParse->pNewTable = 0;
  }
}

................................................................................
  sCtx.pTab = pTab;
  sCtx.pVTable = pVTable;
  sCtx.pPrior = db->pVtabCtx;
  sCtx.bDeclared = 0;
  db->pVtabCtx = &sCtx;
  rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr);
  db->pVtabCtx = sCtx.pPrior;
  if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
  assert( sCtx.pTab==pTab );

  if( SQLITE_OK!=rc ){
    if( zErr==0 ){
      *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName);
    }else {
      *pzErr = sqlite3MPrintf(db, "%s", zErr);
................................................................................
  FuncDef *pDef,  /* Function to possibly overload */
  int nArg,       /* Number of arguments to the function */
  Expr *pExpr     /* First argument to the function */
){
  Table *pTab;
  sqlite3_vtab *pVtab;
  sqlite3_module *pMod;
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**) = 0;
  void *pArg = 0;
  FuncDef *pNew;
  int rc = 0;
  char *zLowerName;
  unsigned char *z;


................................................................................
  ** to see if the implementation wants to overload this function 
  */
  zLowerName = sqlite3DbStrDup(db, pDef->zName);
  if( zLowerName ){
    for(z=(unsigned char*)zLowerName; *z; z++){
      *z = sqlite3UpperToLower[*z];
    }
    rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xFunc, &pArg);
    sqlite3DbFree(db, zLowerName);
  }
  if( rc==0 ){
    return pDef;
  }

  /* Create a new ephemeral function definition for the overloaded
................................................................................
                             + sqlite3Strlen30(pDef->zName) + 1);
  if( pNew==0 ){
    return pDef;
  }
  *pNew = *pDef;
  pNew->zName = (char *)&pNew[1];
  memcpy(pNew->zName, pDef->zName, sqlite3Strlen30(pDef->zName)+1);
  pNew->xFunc = xFunc;
  pNew->pUserData = pArg;
  pNew->funcFlags |= SQLITE_FUNC_EPHEM;
  return pNew;
}

/*
** Make sure virtual table pTab is contained in the pParse->apVirtualLock[]
................................................................................
  }
  n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]);
  apVtabLock = sqlite3_realloc64(pToplevel->apVtabLock, n);
  if( apVtabLock ){
    pToplevel->apVtabLock = apVtabLock;
    pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab;
  }else{
    pToplevel->db->mallocFailed = 1;
  }
}

/*
** Check to see if virtual tale module pMod can be have an eponymous
** virtual table instance.  If it can, create one if one does not already
** exist. Return non-zero if the eponymous virtual table instance exists
................................................................................
  int i, j;

  if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
  sqlite3StrAccumAppend(pStr, " (", 2);
  for(i=0; i<nEq; i++){
    const char *z = explainIndexColumnName(pIndex, i);
    if( i ) sqlite3StrAccumAppend(pStr, " AND ", 5);
    sqlite3XPrintf(pStr, 0, i>=nSkip ? "%s=?" : "ANY(%s)", z);
  }

  j = i;
  if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
    const char *z = explainIndexColumnName(pIndex, i);
    explainAppendTerm(pStr, i++, z, ">");
  }
................................................................................
    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));

    sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
    sqlite3StrAccumAppendAll(&str, isSearch ? "SEARCH" : "SCAN");
    if( pItem->pSelect ){
      sqlite3XPrintf(&str, 0, " SUBQUERY %d", pItem->iSelectId);
    }else{
      sqlite3XPrintf(&str, 0, " TABLE %s", pItem->zName);
    }

    if( pItem->zAlias ){
      sqlite3XPrintf(&str, 0, " AS %s", pItem->zAlias);
    }
    if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
      const char *zFmt = 0;
      Index *pIdx;

      assert( pLoop->u.btree.pIndex!=0 );
      pIdx = pLoop->u.btree.pIndex;
................................................................................
      }else if( flags & WHERE_IDX_ONLY ){
        zFmt = "COVERING INDEX %s";
      }else{
        zFmt = "INDEX %s";
      }
      if( zFmt ){
        sqlite3StrAccumAppend(&str, " USING ", 7);
        sqlite3XPrintf(&str, 0, zFmt, pIdx->zName);
        explainIndexRange(&str, pLoop);
      }
    }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
      const char *zRangeOp;
      if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
        zRangeOp = "=";
      }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
................................................................................
        zRangeOp = ">? AND rowid<";
      }else if( flags&WHERE_BTM_LIMIT ){
        zRangeOp = ">";
      }else{
        assert( flags&WHERE_TOP_LIMIT);
        zRangeOp = "<";
      }
      sqlite3XPrintf(&str, 0, " USING INTEGER PRIMARY KEY (rowid%s?)",zRangeOp);
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
      sqlite3XPrintf(&str, 0, " VIRTUAL TABLE INDEX %d:%s",
                  pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
    }
#endif
#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
    if( pLoop->nOut>=10 ){
      sqlite3XPrintf(&str, 0, " (~%llu rows)", sqlite3LogEstToInt(pLoop->nOut));
    }else{
      sqlite3StrAccumAppend(&str, " (~1 row)", 9);
    }
#endif
    zMsg = sqlite3StrAccumFinish(&str);
    ret = sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg,P4_DYNAMIC);
  }
................................................................................
  }
  while( n>1 && zAff[n-1]==SQLITE_AFF_BLOB ){
    n--;
  }

  /* Code the OP_Affinity opcode if there is anything left to do. */
  if( n>0 ){
    sqlite3VdbeAddOp2(v, OP_Affinity, base, n);
    sqlite3VdbeChangeP4(v, -1, zAff, n);
    sqlite3ExprCacheAffinityChange(pParse, base, n);
  }
}


/*
** Generate code for a single equality term of the WHERE clause.  An equality
................................................................................
  /* Figure out how many memory cells we will need then allocate them.
  */
  regBase = pParse->nMem + 1;
  nReg = pLoop->u.btree.nEq + nExtraReg;
  pParse->nMem += nReg;

  zAff = sqlite3DbStrDup(pParse->db,sqlite3IndexAffinityStr(pParse->db,pIdx));
  if( !zAff ){
    pParse->db->mallocFailed = 1;
  }

  if( nSkip ){
    int iIdxCur = pLevel->iIdxCur;
    sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
    VdbeCoverageIf(v, bRev==0);
    VdbeCoverageIf(v, bRev!=0);
    VdbeComment((v, "begin skip-scan on %s", pIdx->zName));
................................................................................
                      (sHint.pIdx ? sHint.iIdxCur : sHint.iTabCur), 0, 0,
                      (const char*)pExpr, P4_EXPR);
  }
}
#else
# define codeCursorHint(A,B,C)  /* No-op */
#endif /* SQLITE_ENABLE_CURSOR_HINTS */

















































/*
** Generate code for the start of the iLevel-th loop in the WHERE clause
** implementation described by pWInfo.
*/
SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
................................................................................

    /* Seek the table cursor, if required */
    disableTerm(pLevel, pRangeStart);
    disableTerm(pLevel, pRangeEnd);
    if( omitTable ){
      /* pIdx is a covering index.  No need to access the main table. */
    }else if( HasRowid(pIdx->pTable) ){

      iRowidReg = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
      if( pWInfo->eOnePass!=ONEPASS_OFF ){
        sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);
        VdbeCoverage(v);
      }else{
        sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg);  /* Deferred seek */
      }
    }else if( iCur!=iIdxCur ){
      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
      iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
      for(j=0; j<pPk->nKeyCol; j++){
        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
................................................................................
    */
    if( pWC->nTerm>1 ){
      int iTerm;
      for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
        Expr *pExpr = pWC->a[iTerm].pExpr;
        if( &pWC->a[iTerm] == pTerm ) continue;
        if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
        if( (pWC->a[iTerm].wtFlags & TERM_VIRTUAL)!=0 ) continue;


        if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
        pExpr = sqlite3ExprDup(db, pExpr, 0);
        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
      }
      if( pAndExpr ){
        pAndExpr = sqlite3PExpr(pParse, TK_AND|TKFLG_DONTFOLD, 0, pAndExpr, 0);
................................................................................
static int whereClauseInsert(WhereClause *pWC, Expr *p, u16 wtFlags){
  WhereTerm *pTerm;
  int idx;
  testcase( wtFlags & TERM_VIRTUAL );
  if( pWC->nTerm>=pWC->nSlot ){
    WhereTerm *pOld = pWC->a;
    sqlite3 *db = pWC->pWInfo->pParse->db;
    pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
    if( pWC->a==0 ){
      if( wtFlags & TERM_DYNAMIC ){
        sqlite3ExprDelete(db, p);
      }
      pWC->a = pOld;
      return 0;
    }
................................................................................
  ExprList *pList;           /* List of operands to the LIKE operator */
  int c;                     /* One character in z[] */
  int cnt;                   /* Number of non-wildcard prefix characters */
  char wc[3];                /* Wildcard characters */
  sqlite3 *db = pParse->db;  /* Database connection */
  sqlite3_value *pVal = 0;
  int op;                    /* Opcode of pRight */


  if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){
    return 0;
  }
#ifdef SQLITE_EBCDIC
  if( *pnoCase ) return 0;
#endif
................................................................................
        }
      }
    }else{
      z = 0;
    }
  }


  sqlite3ValueFree(pVal);
  return (z!=0);
}
#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */


#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Check to see if the given expression is of the form
................................................................................
  indexable = ~(Bitmask)0;
  chngToIN = ~(Bitmask)0;
  for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){
    if( (pOrTerm->eOperator & WO_SINGLE)==0 ){
      WhereAndInfo *pAndInfo;
      assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 );
      chngToIN = 0;
      pAndInfo = sqlite3DbMallocRaw(db, sizeof(*pAndInfo));
      if( pAndInfo ){
        WhereClause *pAndWC;
        WhereTerm *pAndTerm;
        int j;
        Bitmask b = 0;
        pOrTerm->u.pAndInfo = pAndInfo;
        pOrTerm->wtFlags |= TERM_ANDINFO;
        pOrTerm->eOperator = WO_AND;
        pAndWC = &pAndInfo->wc;
        sqlite3WhereClauseInit(pAndWC, pWC->pWInfo);
        sqlite3WhereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
        sqlite3WhereExprAnalyze(pSrc, pAndWC);
        pAndWC->pOuter = pWC;
        testcase( db->mallocFailed );
        if( !db->mallocFailed ){
          for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){
            assert( pAndTerm->pExpr );
            if( allowedOp(pAndTerm->pExpr->op) ){
              b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
            }
          }
................................................................................

  TRACE_IDX_INPUTS(p);
  rc = pVtab->pModule->xBestIndex(pVtab, p);
  TRACE_IDX_OUTPUTS(p);

  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_NOMEM ){
      pParse->db->mallocFailed = 1;
    }else if( !pVtab->zErrMsg ){
      sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));
    }else{
      sqlite3ErrorMsg(pParse, "%s", pVtab->zErrMsg);
    }
  }
  sqlite3_free(pVtab->zErrMsg);
................................................................................
/*
** Increase the memory allocation for pLoop->aLTerm[] to be at least n.
*/
static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){
  WhereTerm **paNew;
  if( p->nLSlot>=n ) return SQLITE_OK;
  n = (n+7)&~7;
  paNew = sqlite3DbMallocRaw(db, sizeof(p->aLTerm[0])*n);
  if( paNew==0 ) return SQLITE_NOMEM;
  memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot);
  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
  p->aLTerm = paNew;
  p->nLSlot = n;
  return SQLITE_OK;
}
................................................................................
    }
    sqlite3DebugPrintf("    add: ");
    whereLoopPrint(pTemplate, pBuilder->pWC);
  }
#endif
  if( p==0 ){
    /* Allocate a new WhereLoop to add to the end of the list */
    *ppPrev = p = sqlite3DbMallocRaw(db, sizeof(WhereLoop));
    if( p==0 ) return SQLITE_NOMEM;
    whereLoopInit(p);
    p->pNextLoop = 0;
  }else{
    /* We will be overwriting WhereLoop p[].  But before we do, first
    ** go through the rest of the list and delete any other entries besides
    ** p[] that are also supplated by pTemplate */
................................................................................

/*
** Return the cost of sorting nRow rows, assuming that the keys have 
** nOrderby columns and that the first nSorted columns are already in
** order.
*/
static LogEst whereSortingCost(
  WhereInfo *pWInfo,
  LogEst nRow,
  int nOrderBy,
  int nSorted
){
  /* TUNING: Estimated cost of a full external sort, where N is 
  ** the number of rows to sort is:
  **
................................................................................
  **
  ** The (Y/X) term is implemented using stack variable rScale
  ** below.  */
  LogEst rScale, rSortCost;
  assert( nOrderBy>0 && 66==sqlite3LogEst(100) );
  rScale = sqlite3LogEst((nOrderBy-nSorted)*100/nOrderBy) - 66;
  rSortCost = nRow + estLog(nRow) + rScale + 16;

  /* TUNING: The cost of implementing DISTINCT using a B-TREE is
  ** similar but with a larger constant of proportionality. 
  ** Multiply by an additional factor of 3.0.  */
  if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){
    rSortCost += 16;
  }

  return rSortCost;
}

/*
** Given the list of WhereLoop objects at pWInfo->pLoops, this routine
** attempts to find the lowest cost path that visits each WhereLoop
** once.  This path is then loaded into the pWInfo->a[].pWLoop fields.
................................................................................
  }else{
    nOrderBy = pWInfo->pOrderBy->nExpr;
  }

  /* Allocate and initialize space for aTo, aFrom and aSortCost[] */
  nSpace = (sizeof(WherePath)+sizeof(WhereLoop*)*nLoop)*mxChoice*2;
  nSpace += sizeof(LogEst) * nOrderBy;
  pSpace = sqlite3DbMallocRaw(db, nSpace);
  if( pSpace==0 ) return SQLITE_NOMEM;
  aTo = (WherePath*)pSpace;
  aFrom = aTo+mxChoice;
  memset(aFrom, 0, sizeof(aFrom[0]));
  pX = (WhereLoop**)(aFrom+mxChoice);
  for(ii=mxChoice*2, pFrom=aTo; ii>0; ii--, pFrom++, pX += nLoop){
    pFrom->aLoop = pX;
................................................................................
                       iLoop, pWLoop, &revMask);
        }else{
          revMask = pFrom->revLoop;
        }
        if( isOrdered>=0 && isOrdered<nOrderBy ){
          if( aSortCost[isOrdered]==0 ){
            aSortCost[isOrdered] = whereSortingCost(
                pWInfo, nRowEst, nOrderBy, isOrdered
            );
          }
          rCost = sqlite3LogEstAdd(rUnsorted, aSortCost[isOrdered]);

          WHERETRACE(0x002,
              ("---- sort cost=%-3d (%d/%d) increases cost %3d to %-3d\n",
               aSortCost[isOrdered], (nOrderBy-isOrdered), nOrderBy, 
................................................................................
  WhereLoopBuilder sWLB;     /* The WhereLoop builder */
  WhereMaskSet *pMaskSet;    /* The expression mask set */
  WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
  int ii;                    /* Loop counter */
  sqlite3 *db;               /* Database connection */
  int rc;                    /* Return code */
  u8 bFordelete = 0;

  assert( (wctrlFlags & WHERE_ONEPASS_MULTIROW)==0 || (
        (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 
     && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 
  ));

  /* Variable initialization */
................................................................................
    }
  }
  WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));
  pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;

  /* If the caller is an UPDATE or DELETE statement that is requesting
  ** to use a one-pass algorithm, determine if this is appropriate.
  ** The one-pass algorithm only works if the WHERE clause constrains
  ** the statement to update or delete a single row.
  */
  assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 ){
    int wsFlags = pWInfo->a[0].pWLoop->wsFlags;
    int bOnerow = (wsFlags & WHERE_ONEROW)!=0;

    if( bOnerow || ( (wctrlFlags & WHERE_ONEPASS_MULTIROW)
       && 0==(wsFlags & WHERE_VIRTUALTABLE)
    )){
      pWInfo->eOnePass = bOnerow ? ONEPASS_SINGLE : ONEPASS_MULTI;
      if( HasRowid(pTabList->a[0].pTab) && (wsFlags & WHERE_IDX_ONLY) ){
        if( wctrlFlags & WHERE_ONEPASS_MULTIROW ){
          bFordelete = OPFLAG_FORDELETE;
        }
        pWInfo->a[0].pWLoop->wsFlags = (wsFlags & ~WHERE_IDX_ONLY);
      }
................................................................................
      assert( pTabItem->iCursor==pLevel->iTabCur );
      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS-1 );
      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS );
      if( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol<BMS && HasRowid(pTab) ){
        Bitmask b = pTabItem->colUsed;
        int n = 0;
        for(; b; b=b>>1, n++){}
        sqlite3VdbeChangeP4(v, sqlite3VdbeCurrentAddr(v)-1, 
                            SQLITE_INT_TO_PTR(n), P4_INT32);
        assert( n<=pTab->nCol );
      }
#ifdef SQLITE_ENABLE_CURSOR_HINTS
      if( pLoop->u.btree.pIndex!=0 ){
        sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ|bFordelete);
      }else
#endif
................................................................................
struct TrigEvent { int a; IdList * b; };

/*
** An instance of this structure holds the ATTACH key and the key type.
*/
struct AttachKey { int type;  Token key; };











  /*
  ** For a compound SELECT statement, make sure p->pPrior->pNext==p for
  ** all elements in the list.  And make sure list length does not exceed
  ** SQLITE_LIMIT_COMPOUND_SELECT.
  */
  static void parserDoubleLinkSelect(Parse *pParse, Select *p){
................................................................................
    pOut->zEnd = &pPostOp->z[pPostOp->n];
  }                           

  /* A routine to convert a binary TK_IS or TK_ISNOT expression into a
  ** unary TK_ISNULL or TK_NOTNULL expression. */
  static void binaryToUnaryIfNull(Parse *pParse, Expr *pY, Expr *pA, int op){
    sqlite3 *db = pParse->db;
    if( pY && pA && pY->op==TK_NULL ){
      pA->op = (u8)op;
      sqlite3ExprDelete(db, pA->pRight);
      pA->pRight = 0;
    }
  }

  /* Construct an expression node for a unary prefix operator
................................................................................
  **   case 0:
  **  #line <lineno> <grammarfile>
  **     { ... }           // User supplied code
  **  #line <lineno> <thisfile>
  **     break;
  */
/********** Begin reduce actions **********************************************/
      case 5: /* explain ::= */
{ sqlite3BeginParse(pParse, 0); }
        break;
      case 6: /* explain ::= EXPLAIN */
{ sqlite3BeginParse(pParse, 1); }

        break;
      case 7: /* explain ::= EXPLAIN QUERY PLAN */
{ sqlite3BeginParse(pParse, 2); }

        break;
      case 8: /* cmdx ::= cmd */
{ sqlite3FinishCoding(pParse); }
        break;
      case 9: /* cmd ::= BEGIN transtype trans_opt */
{sqlite3BeginTransaction(pParse, yymsp[-1].minor.yy4);}
        break;
................................................................................
      case 26: /* create_table ::= createkw temp TABLE ifnotexists nm dbnm */
{
   sqlite3StartTable(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,yymsp[-4].minor.yy4,0,0,yymsp[-2].minor.yy4);
}
        break;
      case 27: /* createkw ::= CREATE */
{
  pParse->db->lookaside.bEnabled = 0;
  yygotominor.yy0 = yymsp[0].minor.yy0;
}
        break;
      case 28: /* ifnotexists ::= */
      case 31: /* temp ::= */ yytestcase(yyruleno==31);
      case 34: /* table_options ::= */ yytestcase(yyruleno==34);
      case 68: /* autoinc ::= */ yytestcase(yyruleno==68);
................................................................................
      case 306: /* cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt column */
{
  sqlite3AlterFinishAddColumn(pParse, &yymsp[0].minor.yy0);
}
        break;
      case 307: /* add_column_fullname ::= fullname */
{
  pParse->db->lookaside.bEnabled = 0;
  sqlite3AlterBeginAddColumn(pParse, yymsp[0].minor.yy259);
}
        break;
      case 310: /* cmd ::= create_vtab */
{sqlite3VtabFinishParse(pParse,0);}
        break;
      case 311: /* cmd ::= create_vtab LP vtabarglist RP */
................................................................................
        break;
      default:
      /* (0) input ::= cmdlist */ yytestcase(yyruleno==0);
      /* (1) cmdlist ::= cmdlist ecmd */ yytestcase(yyruleno==1);
      /* (2) cmdlist ::= ecmd */ yytestcase(yyruleno==2);
      /* (3) ecmd ::= SEMI */ yytestcase(yyruleno==3);
      /* (4) ecmd ::= explain cmdx SEMI */ yytestcase(yyruleno==4);

      /* (10) trans_opt ::= */ yytestcase(yyruleno==10);
      /* (11) trans_opt ::= TRANSACTION */ yytestcase(yyruleno==11);
      /* (12) trans_opt ::= TRANSACTION nm */ yytestcase(yyruleno==12);
      /* (20) savepoint_opt ::= SAVEPOINT */ yytestcase(yyruleno==20);
      /* (21) savepoint_opt ::= */ yytestcase(yyruleno==21);
      /* (25) cmd ::= create_table create_table_args */ yytestcase(yyruleno==25);
      /* (36) columnlist ::= columnlist COMMA column */ yytestcase(yyruleno==36);
................................................................................
** This file contains C code that splits an SQL input string up into
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
*/
/* #include "sqliteInt.h" */
/* #include <stdlib.h> */















































































/*
** The charMap() macro maps alphabetic characters into their
** lower-case ASCII equivalent.  On ASCII machines, this is just
** an upper-to-lower case map.  On EBCDIC machines we also need
** to adjust the encoding.  Only alphabetic characters and underscores
** need to be translated.



*/
#ifdef SQLITE_ASCII
# define charMap(X) sqlite3UpperToLower[(unsigned char)X]
#endif
#ifdef SQLITE_EBCDIC
# define charMap(X) ebcdicToAscii[(unsigned char)X]
const unsigned char ebcdicToAscii[] = {
................................................................................

/*
** The sqlite3KeywordCode function looks up an identifier to determine if
** it is a keyword.  If it is a keyword, the token code of that keyword is 
** returned.  If the input is not a keyword, TK_ID is returned.
**
** The implementation of this routine was generated by a program,
** mkkeywordhash.h, located in the tool subdirectory of the distribution.
** The output of the mkkeywordhash.c program is written into a file
** named keywordhash.h and then included into this source file by
** the #include below.
*/
/************** Include keywordhash.h in the middle of tokenize.c ************/
/************** Begin file keywordhash.h *************************************/
/***** This file contains automatically generated code ******
................................................................................
    TK_COLUMNKW,   TK_COMMIT,     TK_CONFLICT,   TK_JOIN_KW,    TK_CTIME_KW,   
    TK_CTIME_KW,   TK_PRIMARY,    TK_DEFERRED,   TK_DISTINCT,   TK_IS,         
    TK_DROP,       TK_FAIL,       TK_FROM,       TK_JOIN_KW,    TK_LIKE_KW,    
    TK_BY,         TK_IF,         TK_ISNULL,     TK_ORDER,      TK_RESTRICT,   
    TK_JOIN_KW,    TK_ROLLBACK,   TK_ROW,        TK_UNION,      TK_USING,      
    TK_VACUUM,     TK_VIEW,       TK_INITIALLY,  TK_ALL,        
  };
  int h, i;

  if( n>=2 ){
    h = ((charMap(z[0])*4) ^ (charMap(z[n-1])*3) ^ n) % 127;
    for(i=((int)aHash[h])-1; i>=0; i=((int)aNext[i])-1){


      if( aLen[i]==n && sqlite3StrNICmp(&zText[aOffset[i]],z,n)==0 ){







        testcase( i==0 ); /* REINDEX */
        testcase( i==1 ); /* INDEXED */
        testcase( i==2 ); /* INDEX */
        testcase( i==3 ); /* DESC */
        testcase( i==4 ); /* ESCAPE */
        testcase( i==5 ); /* EACH */
        testcase( i==6 ); /* CHECK */
        testcase( i==7 ); /* KEY */
        testcase( i==8 ); /* BEFORE */
        testcase( i==9 ); /* FOREIGN */
        testcase( i==10 ); /* FOR */
        testcase( i==11 ); /* IGNORE */
        testcase( i==12 ); /* REGEXP */
        testcase( i==13 ); /* EXPLAIN */
        testcase( i==14 ); /* INSTEAD */
        testcase( i==15 ); /* ADD */
        testcase( i==16 ); /* DATABASE */
        testcase( i==17 ); /* AS */
        testcase( i==18 ); /* SELECT */
        testcase( i==19 ); /* TABLE */
        testcase( i==20 ); /* LEFT */
        testcase( i==21 ); /* THEN */
        testcase( i==22 ); /* END */
        testcase( i==23 ); /* DEFERRABLE */
        testcase( i==24 ); /* ELSE */
        testcase( i==25 ); /* EXCEPT */
        testcase( i==26 ); /* TRANSACTION */
        testcase( i==27 ); /* ACTION */
        testcase( i==28 ); /* ON */
        testcase( i==29 ); /* NATURAL */
        testcase( i==30 ); /* ALTER */
        testcase( i==31 ); /* RAISE */
        testcase( i==32 ); /* EXCLUSIVE */
        testcase( i==33 ); /* EXISTS */
        testcase( i==34 ); /* SAVEPOINT */
        testcase( i==35 ); /* INTERSECT */
        testcase( i==36 ); /* TRIGGER */
        testcase( i==37 ); /* REFERENCES */
        testcase( i==38 ); /* CONSTRAINT */
        testcase( i==39 ); /* INTO */
        testcase( i==40 ); /* OFFSET */
        testcase( i==41 ); /* OF */
        testcase( i==42 ); /* SET */
        testcase( i==43 ); /* TEMPORARY */
        testcase( i==44 ); /* TEMP */
        testcase( i==45 ); /* OR */
        testcase( i==46 ); /* UNIQUE */
        testcase( i==47 ); /* QUERY */
        testcase( i==48 ); /* WITHOUT */
        testcase( i==49 ); /* WITH */
        testcase( i==50 ); /* OUTER */
        testcase( i==51 ); /* RELEASE */
        testcase( i==52 ); /* ATTACH */
        testcase( i==53 ); /* HAVING */
        testcase( i==54 ); /* GROUP */
        testcase( i==55 ); /* UPDATE */
        testcase( i==56 ); /* BEGIN */
        testcase( i==57 ); /* INNER */
        testcase( i==58 ); /* RECURSIVE */
        testcase( i==59 ); /* BETWEEN */
        testcase( i==60 ); /* NOTNULL */
        testcase( i==61 ); /* NOT */
        testcase( i==62 ); /* NO */
        testcase( i==63 ); /* NULL */
        testcase( i==64 ); /* LIKE */
        testcase( i==65 ); /* CASCADE */
        testcase( i==66 ); /* ASC */
        testcase( i==67 ); /* DELETE */
        testcase( i==68 ); /* CASE */
        testcase( i==69 ); /* COLLATE */
        testcase( i==70 ); /* CREATE */
        testcase( i==71 ); /* CURRENT_DATE */
        testcase( i==72 ); /* DETACH */
        testcase( i==73 ); /* IMMEDIATE */
        testcase( i==74 ); /* JOIN */
        testcase( i==75 ); /* INSERT */
        testcase( i==76 ); /* MATCH */
        testcase( i==77 ); /* PLAN */
        testcase( i==78 ); /* ANALYZE */
        testcase( i==79 ); /* PRAGMA */
        testcase( i==80 ); /* ABORT */
        testcase( i==81 ); /* VALUES */
        testcase( i==82 ); /* VIRTUAL */
        testcase( i==83 ); /* LIMIT */
        testcase( i==84 ); /* WHEN */
        testcase( i==85 ); /* WHERE */
        testcase( i==86 ); /* RENAME */
        testcase( i==87 ); /* AFTER */
        testcase( i==88 ); /* REPLACE */
        testcase( i==89 ); /* AND */
        testcase( i==90 ); /* DEFAULT */
        testcase( i==91 ); /* AUTOINCREMENT */
        testcase( i==92 ); /* TO */
        testcase( i==93 ); /* IN */
        testcase( i==94 ); /* CAST */
        testcase( i==95 ); /* COLUMN */
        testcase( i==96 ); /* COMMIT */
        testcase( i==97 ); /* CONFLICT */
        testcase( i==98 ); /* CROSS */
        testcase( i==99 ); /* CURRENT_TIMESTAMP */
        testcase( i==100 ); /* CURRENT_TIME */
        testcase( i==101 ); /* PRIMARY */
        testcase( i==102 ); /* DEFERRED */
        testcase( i==103 ); /* DISTINCT */
        testcase( i==104 ); /* IS */
        testcase( i==105 ); /* DROP */
        testcase( i==106 ); /* FAIL */
        testcase( i==107 ); /* FROM */
        testcase( i==108 ); /* FULL */
        testcase( i==109 ); /* GLOB */
        testcase( i==110 ); /* BY */
        testcase( i==111 ); /* IF */
        testcase( i==112 ); /* ISNULL */
        testcase( i==113 ); /* ORDER */
        testcase( i==114 ); /* RESTRICT */
        testcase( i==115 ); /* RIGHT */
        testcase( i==116 ); /* ROLLBACK */
        testcase( i==117 ); /* ROW */
        testcase( i==118 ); /* UNION */
        testcase( i==119 ); /* USING */
        testcase( i==120 ); /* VACUUM */
        testcase( i==121 ); /* VIEW */
        testcase( i==122 ); /* INITIALLY */
        testcase( i==123 ); /* ALL */
        *pType = aCode[i];
        break;
      }
    }
  }
  return n;
}
SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char *z, int n){
  int id = TK_ID;
  keywordCode((char*)z, n, &id);
................................................................................
/* Make the IdChar function accessible from ctime.c */
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
SQLITE_PRIVATE int sqlite3IsIdChar(u8 c){ return IdChar(c); }
#endif


/*
** Return the length of the token that begins at z[0]. 
** Store the token type in *tokenType before returning.
*/
SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
  int i, c;
  switch( *z ){
    case ' ': case '\t': case '\n': case '\f': case '\r': {


      testcase( z[0]==' ' );
      testcase( z[0]=='\t' );
      testcase( z[0]=='\n' );
      testcase( z[0]=='\f' );
      testcase( z[0]=='\r' );
      for(i=1; sqlite3Isspace(z[i]); i++){}
      *tokenType = TK_SPACE;
      return i;
    }
    case '-': {
      if( z[1]=='-' ){
        for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
        *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
        return i;
      }
      *tokenType = TK_MINUS;
      return 1;
    }
    case '(': {
      *tokenType = TK_LP;
      return 1;
    }
    case ')': {
      *tokenType = TK_RP;
      return 1;
    }
    case ';': {
      *tokenType = TK_SEMI;
      return 1;
    }
    case '+': {
      *tokenType = TK_PLUS;
      return 1;
    }
    case '*': {
      *tokenType = TK_STAR;
      return 1;
    }
    case '/': {
      if( z[1]!='*' || z[2]==0 ){
        *tokenType = TK_SLASH;
        return 1;
      }
      for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
      if( c ) i++;
      *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
      return i;
    }
    case '%': {
      *tokenType = TK_REM;
      return 1;
    }
    case '=': {
      *tokenType = TK_EQ;
      return 1 + (z[1]=='=');
    }
    case '<': {
      if( (c=z[1])=='=' ){
        *tokenType = TK_LE;
        return 2;
      }else if( c=='>' ){
        *tokenType = TK_NE;
        return 2;
      }else if( c=='<' ){
................................................................................
        *tokenType = TK_LSHIFT;
        return 2;
      }else{
        *tokenType = TK_LT;
        return 1;
      }
    }
    case '>': {
      if( (c=z[1])=='=' ){
        *tokenType = TK_GE;
        return 2;
      }else if( c=='>' ){
        *tokenType = TK_RSHIFT;
        return 2;
      }else{
        *tokenType = TK_GT;
        return 1;
      }
    }
    case '!': {
      if( z[1]!='=' ){
        *tokenType = TK_ILLEGAL;
        return 2;
      }else{
        *tokenType = TK_NE;
        return 2;
      }
    }
    case '|': {
      if( z[1]!='|' ){
        *tokenType = TK_BITOR;
        return 1;
      }else{
        *tokenType = TK_CONCAT;
        return 2;
      }
    }
    case ',': {
      *tokenType = TK_COMMA;
      return 1;
    }
    case '&': {
      *tokenType = TK_BITAND;
      return 1;
    }
    case '~': {
      *tokenType = TK_BITNOT;
      return 1;
    }
    case '`':
    case '\'':
    case '"': {
      int delim = z[0];
      testcase( delim=='`' );
      testcase( delim=='\'' );
      testcase( delim=='"' );
      for(i=1; (c=z[i])!=0; i++){
        if( c==delim ){
          if( z[i+1]==delim ){
................................................................................
        *tokenType = TK_ID;
        return i+1;
      }else{
        *tokenType = TK_ILLEGAL;
        return i;
      }
    }
    case '.': {
#ifndef SQLITE_OMIT_FLOATING_POINT
      if( !sqlite3Isdigit(z[1]) )
#endif
      {
        *tokenType = TK_DOT;
        return 1;
      }
      /* If the next character is a digit, this is a floating point
      ** number that begins with ".".  Fall thru into the next case */
    }
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9': {
      testcase( z[0]=='0' );  testcase( z[0]=='1' );  testcase( z[0]=='2' );
      testcase( z[0]=='3' );  testcase( z[0]=='4' );  testcase( z[0]=='5' );
      testcase( z[0]=='6' );  testcase( z[0]=='7' );  testcase( z[0]=='8' );
      testcase( z[0]=='9' );
      *tokenType = TK_INTEGER;
#ifndef SQLITE_OMIT_HEX_INTEGER
      if( z[0]=='0' && (z[1]=='x' || z[1]=='X') && sqlite3Isxdigit(z[2]) ){
................................................................................
#endif
      while( IdChar(z[i]) ){
        *tokenType = TK_ILLEGAL;
        i++;
      }
      return i;
    }
    case '[': {
      for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}
      *tokenType = c==']' ? TK_ID : TK_ILLEGAL;
      return i;
    }
    case '?': {
      *tokenType = TK_VARIABLE;
      for(i=1; sqlite3Isdigit(z[i]); i++){}
      return i;
    }
#ifndef SQLITE_OMIT_TCL_VARIABLE
    case '$':
#endif
    case '@':  /* For compatibility with MS SQL Server */
    case '#':
    case ':': {
      int n = 0;
      testcase( z[0]=='$' );  testcase( z[0]=='@' );
      testcase( z[0]==':' );  testcase( z[0]=='#' );
      *tokenType = TK_VARIABLE;
      for(i=1; (c=z[i])!=0; i++){
        if( IdChar(c) ){
          n++;
................................................................................
        }else{
          break;
        }
      }
      if( n==0 ) *tokenType = TK_ILLEGAL;
      return i;
    }












#ifndef SQLITE_OMIT_BLOB_LITERAL
    case 'x': case 'X': {

      testcase( z[0]=='x' ); testcase( z[0]=='X' );
      if( z[1]=='\'' ){
        *tokenType = TK_BLOB;
        for(i=2; sqlite3Isxdigit(z[i]); i++){}
        if( z[i]!='\'' || i%2 ){
          *tokenType = TK_ILLEGAL;
          while( z[i] && z[i]!='\'' ){ i++; }
        }
        if( z[i] ) i++;
        return i;
      }
      /* Otherwise fall through to the next case */

    }
#endif
    default: {
      if( !IdChar(*z) ){

        break;
      }
      for(i=1; IdChar(z[i]); i++){}

      *tokenType = TK_ID;
      return keywordCode((char*)z, i, tokenType);

    }
  }

  *tokenType = TK_ILLEGAL;
  return 1;
}

/*
** Run the parser on the given SQL string.  The parser structure is
** passed in.  An SQLITE_ status code is returned.  If an error occurs
** then an and attempt is made to write an error message into 
** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that
................................................................................
*/
SQLITE_PRIVATE int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
  int nErr = 0;                   /* Number of errors encountered */
  int i;                          /* Loop counter */
  void *pEngine;                  /* The LEMON-generated LALR(1) parser */
  int tokenType;                  /* type of the next token */
  int lastTokenParsed = -1;       /* type of the previous token */
  u8 enableLookaside;             /* Saved value of db->lookaside.bEnabled */
  sqlite3 *db = pParse->db;       /* The database connection */
  int mxSqlLen;                   /* Max length of an SQL string */

  assert( zSql!=0 );
  mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
  if( db->nVdbeActive==0 ){
    db->u1.isInterrupted = 0;
................................................................................
  pParse->rc = SQLITE_OK;
  pParse->zTail = zSql;
  i = 0;
  assert( pzErrMsg!=0 );
  /* sqlite3ParserTrace(stdout, "parser: "); */
  pEngine = sqlite3ParserAlloc(sqlite3Malloc);
  if( pEngine==0 ){
    db->mallocFailed = 1;
    return SQLITE_NOMEM;
  }
  assert( pParse->pNewTable==0 );
  assert( pParse->pNewTrigger==0 );
  assert( pParse->nVar==0 );
  assert( pParse->nzVar==0 );
  assert( pParse->azVar==0 );
  enableLookaside = db->lookaside.bEnabled;
  if( db->lookaside.pStart ) db->lookaside.bEnabled = 1;
  while( zSql[i]!=0 ){
    assert( i>=0 );
    pParse->sLastToken.z = &zSql[i];
    pParse->sLastToken.n = sqlite3GetToken((unsigned char*)&zSql[i],&tokenType);
    i += pParse->sLastToken.n;
    if( i>mxSqlLen ){
      pParse->rc = SQLITE_TOOBIG;
      break;
    }
    if( tokenType>=TK_SPACE ){
      assert( tokenType==TK_SPACE || tokenType==TK_ILLEGAL );
      if( db->u1.isInterrupted ){
        sqlite3ErrorMsg(pParse, "interrupt");
        pParse->rc = SQLITE_INTERRUPT;
        break;
      }
      if( tokenType==TK_ILLEGAL ){
        sqlite3ErrorMsg(pParse, "unrecognized token: \"%T\"",
                        &pParse->sLastToken);
        break;
................................................................................
  sqlite3_mutex_enter(sqlite3MallocMutex());
  sqlite3StatusHighwater(SQLITE_STATUS_PARSER_STACK,
      sqlite3ParserStackPeak(pEngine)
  );
  sqlite3_mutex_leave(sqlite3MallocMutex());
#endif /* YYDEBUG */
  sqlite3ParserFree(pEngine, sqlite3_free);
  db->lookaside.bEnabled = enableLookaside;
  if( db->mallocFailed ){
    pParse->rc = SQLITE_NOMEM;
  }
  if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
    pParse->zErrMsg = sqlite3MPrintf(db, "%s", sqlite3ErrStr(pParse->rc));
  }
  assert( pzErrMsg!=0 );
................................................................................
    p = (LookasideSlot*)pStart;
    for(i=cnt-1; i>=0; i--){
      p->pNext = db->lookaside.pFree;
      db->lookaside.pFree = p;
      p = (LookasideSlot*)&((u8*)p)[sz];
    }
    db->lookaside.pEnd = p;
    db->lookaside.bEnabled = 1;
    db->lookaside.bMalloced = pBuf==0 ?1:0;
  }else{
    db->lookaside.pStart = db;
    db->lookaside.pEnd = db;
    db->lookaside.bEnabled = 0;
    db->lookaside.bMalloced = 0;
  }
#endif /* SQLITE_OMIT_LOOKASIDE */
  return SQLITE_OK;
}

/*
................................................................................
*/
SQLITE_PRIVATE int sqlite3CreateFunc(
  sqlite3 *db,
  const char *zFunctionName,
  int nArg,
  int enc,
  void *pUserData,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  FuncDestructor *pDestructor
){
  FuncDef *p;
  int nName;
  int extraFlags;

  assert( sqlite3_mutex_held(db->mutex) );
  if( zFunctionName==0 ||
      (xFunc && (xFinal || xStep)) || 
      (!xFunc && (xFinal && !xStep)) ||
      (!xFunc && (!xFinal && xStep)) ||
      (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
      (255<(nName = sqlite3Strlen30( zFunctionName))) ){
    return SQLITE_MISUSE_BKPT;
  }

  assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
  extraFlags = enc &  SQLITE_DETERMINISTIC;
................................................................................
  ** to the hash table.
  */
  if( enc==SQLITE_UTF16 ){
    enc = SQLITE_UTF16NATIVE;
  }else if( enc==SQLITE_ANY ){
    int rc;
    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
         pUserData, xFunc, xStep, xFinal, pDestructor);
    if( rc==SQLITE_OK ){
      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
          pUserData, xFunc, xStep, xFinal, pDestructor);
    }
    if( rc!=SQLITE_OK ){
      return rc;
    }
    enc = SQLITE_UTF16BE;
  }
#else
................................................................................

  if( pDestructor ){
    pDestructor->nRef++;
  }
  p->pDestructor = pDestructor;
  p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
  testcase( p->funcFlags & SQLITE_DETERMINISTIC );
  p->xFunc = xFunc;
  p->xStep = xStep;
  p->xFinalize = xFinal;
  p->pUserData = pUserData;
  p->nArg = (u16)nArg;
  return SQLITE_OK;
}

/*
................................................................................
*/
SQLITE_API int SQLITE_STDCALL sqlite3_create_function(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*)
){
  return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xFunc, xStep,
                                    xFinal, 0);
}

SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  void (*xDestroy)(void *)
){
  int rc = SQLITE_ERROR;
  FuncDestructor *pArg = 0;

................................................................................
    if( !pArg ){
      xDestroy(p);
      goto out;
    }
    pArg->xDestroy = xDestroy;
    pArg->pUserData = p;
  }
  rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xFunc, xStep, xFinal, pArg);
  if( pArg && pArg->nRef==0 ){
    assert( rc!=SQLITE_OK );
    xDestroy(p);
    sqlite3DbFree(db, pArg);
  }

 out:
................................................................................
#ifndef SQLITE_OMIT_UTF16
SQLITE_API int SQLITE_STDCALL sqlite3_create_function16(
  sqlite3 *db,
  const void *zFunctionName,
  int nArg,
  int eTextRep,
  void *p,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
){
  int rc;
  char *zFunc8;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal,0);
  sqlite3DbFree(db, zFunc8);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}
#endif

................................................................................
      z = sqlite3_value_text16(db->pErr);
    }
    /* A malloc() may have failed within the call to sqlite3_value_text16()
    ** above. If this is the case, then the db->mallocFailed flag needs to
    ** be cleared before returning. Do this directly, instead of via
    ** sqlite3ApiExit(), to avoid setting the database handle error message.
    */
    db->mallocFailed = 0;
  }
  sqlite3_mutex_leave(db->mutex);
  return z;
}
#endif /* SQLITE_OMIT_UTF16 */

/*
................................................................................
  db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
  assert( db->pDfltColl!=0 );

  /* Parse the filename/URI argument. */
  db->openFlags = flags;
  rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
    sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
    sqlite3_free(zErrMsg);
    goto opendb_out;
  }

  /* Open the backend database driver */
  rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
................................................................................
    ** assert() is disabled, then the return value is zero.  If X is
    ** false and assert() is enabled, then the assertion fires and the
    ** process aborts.  If X is false and assert() is disabled, then the
    ** return value is zero.
    */
    case SQLITE_TESTCTRL_ASSERT: {
      volatile int x = 0;
      assert( (x = va_arg(ap,int))!=0 );
      rc = x;
      break;
    }


    /*
    **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
................................................................................
*/
#ifndef _FTSINT_H
#define _FTSINT_H

#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
# define NDEBUG 1
#endif







/*
** FTS4 is really an extension for FTS3.  It is enabled using the
** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
*/
#if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
................................................................................

  pHash = (Fts3Hash *)sqlite3_user_data(context);

  zName = sqlite3_value_text(argv[0]);
  nName = sqlite3_value_bytes(argv[0])+1;

  if( argc==2 ){

    void *pOld;
    int n = sqlite3_value_bytes(argv[1]);
    if( zName==0 || n!=sizeof(pPtr) ){
      sqlite3_result_error(context, "argument type mismatch", -1);
      return;
    }
    pPtr = *(void **)sqlite3_value_blob(argv[1]);
    pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr);
    if( pOld==pPtr ){
      sqlite3_result_error(context, "out of memory", -1);
      return;
    }






  }else{

    if( zName ){
      pPtr = sqlite3Fts3HashFind(pHash, zName, nName);
    }
    if( !pPtr ){
      char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName);
      sqlite3_result_error(context, zErr, -1);
      sqlite3_free(zErr);
................................................................................
    sqlite3_result_error(context, zErr, -1);
  }else{
    sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT);
  }
  Tcl_DecrRefCount(pRet);
}


static
int registerTokenizer(
  sqlite3 *db, 
  char *zName, 
  const sqlite3_tokenizer_module *p
){
  int rc;
................................................................................

  sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);
  sqlite3_bind_blob(pStmt, 2, &p, sizeof(p), SQLITE_STATIC);
  sqlite3_step(pStmt);

  return sqlite3_finalize(pStmt);
}



static
int queryTokenizer(
  sqlite3 *db, 
  char *zName,  
  const sqlite3_tokenizer_module **pp
){
................................................................................
  assert( p1==p2 );
  rc = queryTokenizer(db, "nosuchtokenizer", &p2);
  assert( rc==SQLITE_ERROR );
  assert( p2==0 );
  assert( 0==strcmp(sqlite3_errmsg(db), "unknown tokenizer: nosuchtokenizer") );

  /* Test the storage function */

  rc = registerTokenizer(db, "nosuchtokenizer", p1);
  assert( rc==SQLITE_OK );
  rc = queryTokenizer(db, "nosuchtokenizer", &p2);
  assert( rc==SQLITE_OK );
  assert( p2==p1 );


  sqlite3_result_text(context, "ok", -1, SQLITE_STATIC);
}

#endif

/*
................................................................................
** immediately without attempting the allocation or modifying the stored
** error code.
*/
static void *rbuMalloc(sqlite3rbu *p, int nByte){
  void *pRet = 0;
  if( p->rc==SQLITE_OK ){
    assert( nByte>0 );
    pRet = sqlite3_malloc(nByte);
    if( pRet==0 ){
      p->rc = SQLITE_NOMEM;
    }else{
      memset(pRet, 0, nByte);
    }
  }
  return pRet;
................................................................................
** if the allocation succeeds, (*pRc) is left unchanged.
*/
static char *rbuStrndup(const char *zStr, int *pRc){
  char *zRet = 0;

  assert( *pRc==SQLITE_OK );
  if( zStr ){
    int nCopy = strlen(zStr) + 1;
    zRet = (char*)sqlite3_malloc(nCopy);
    if( zRet ){
      memcpy(zRet, zStr, nCopy);
    }else{
      *pRc = SQLITE_NOMEM;
    }
  }

................................................................................
    return SQLITE_INTERNAL;
  }

  pRbu->pgsz = iAmt;
  if( pRbu->nFrame==pRbu->nFrameAlloc ){
    int nNew = (pRbu->nFrameAlloc ? pRbu->nFrameAlloc : 64) * 2;
    RbuFrame *aNew;
    aNew = (RbuFrame*)sqlite3_realloc(pRbu->aFrame, nNew * sizeof(RbuFrame));
    if( aNew==0 ) return SQLITE_NOMEM;
    pRbu->aFrame = aNew;
    pRbu->nFrameAlloc = nNew;
  }

  iFrame = (u32)((iOff-32) / (i64)(iAmt+24)) + 1;
  if( pRbu->iMaxFrame<iFrame ) pRbu->iMaxFrame = iFrame;
................................................................................
  int nChar;
  LPWSTR zWideFilename;

  nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);
  if( nChar==0 ){
    return 0;
  }
  zWideFilename = sqlite3_malloc( nChar*sizeof(zWideFilename[0]) );
  if( zWideFilename==0 ){
    return 0;
  }
  memset(zWideFilename, 0, nChar*sizeof(zWideFilename[0]));
  nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename,
                                nChar);
  if( nChar==0 ){
................................................................................
*/
SQLITE_API sqlite3rbu *SQLITE_STDCALL sqlite3rbu_open(
  const char *zTarget, 
  const char *zRbu,
  const char *zState
){
  sqlite3rbu *p;
  int nTarget = strlen(zTarget);
  int nRbu = strlen(zRbu);
  int nState = zState ? strlen(zState) : 0;


  p = (sqlite3rbu*)sqlite3_malloc(sizeof(sqlite3rbu)+nTarget+1+nRbu+1+nState+1);
  if( p ){
    RbuState *pState = 0;

    /* Create the custom VFS. */
    memset(p, 0, sizeof(sqlite3rbu));
    rbuCreateVfs(p);

................................................................................
** If the error code currently stored in the RBU handle is SQLITE_CONSTRAINT,
** then edit any error message string so as to remove all occurrences of
** the pattern "rbu_imp_[0-9]*".
*/
static void rbuEditErrmsg(sqlite3rbu *p){
  if( p->rc==SQLITE_CONSTRAINT && p->zErrmsg ){
    int i;
    int nErrmsg = strlen(p->zErrmsg);
    for(i=0; i<(nErrmsg-8); i++){
      if( memcmp(&p->zErrmsg[i], "rbu_imp_", 8)==0 ){
        int nDel = 8;
        while( p->zErrmsg[i+nDel]>='0' && p->zErrmsg[i+nDel]<='9' ) nDel++;
        memmove(&p->zErrmsg[i], &p->zErrmsg[i+nDel], nErrmsg + 1 - i - nDel);
        nErrmsg -= nDel;
      }
................................................................................
  /* If not in RBU_STAGE_OAL, allow this call to pass through. Or, if this
  ** rbu is in the RBU_STAGE_OAL state, use heap memory for *-shm space 
  ** instead of a file on disk.  */
  assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );
  if( eStage==RBU_STAGE_OAL || eStage==RBU_STAGE_MOVE ){
    if( iRegion<=p->nShm ){
      int nByte = (iRegion+1) * sizeof(char*);
      char **apNew = (char**)sqlite3_realloc(p->apShm, nByte);
      if( apNew==0 ){
        rc = SQLITE_NOMEM;
      }else{
        memset(&apNew[p->nShm], 0, sizeof(char*) * (1 + iRegion - p->nShm));
        p->apShm = apNew;
        p->nShm = iRegion+1;
      }
    }

    if( rc==SQLITE_OK && p->apShm[iRegion]==0 ){
      char *pNew = (char*)sqlite3_malloc(szRegion);
      if( pNew==0 ){
        rc = SQLITE_NOMEM;
      }else{
        memset(pNew, 0, szRegion);
        p->apShm[iRegion] = pNew;
      }
    }
................................................................................
  if( zName ){
    if( flags & SQLITE_OPEN_MAIN_DB ){
      /* A main database has just been opened. The following block sets
      ** (pFd->zWal) to point to a buffer owned by SQLite that contains
      ** the name of the *-wal file this db connection will use. SQLite
      ** happens to pass a pointer to this buffer when using xAccess()
      ** or xOpen() to operate on the *-wal file.  */
      int n = strlen(zName);
      const char *z = &zName[n];
      if( flags & SQLITE_OPEN_URI ){
        int odd = 0;
        while( 1 ){
          if( z[0]==0 ){
            odd = 1 - odd;
            if( odd && z[1]==0 ) break;
................................................................................
      rbu_file *pDb = rbuFindMaindb(pRbuVfs, zName);
      if( pDb ){
        if( pDb->pRbu && pDb->pRbu->eStage==RBU_STAGE_OAL ){
          /* This call is to open a *-wal file. Intead, open the *-oal. This
          ** code ensures that the string passed to xOpen() is terminated by a
          ** pair of '\0' bytes in case the VFS attempts to extract a URI 
          ** parameter from it.  */
          int nCopy = strlen(zName);
          char *zCopy = sqlite3_malloc(nCopy+2);
          if( zCopy ){
            memcpy(zCopy, zName, nCopy);
            zCopy[nCopy-3] = 'o';
            zCopy[nCopy] = '\0';
            zCopy[nCopy+1] = '\0';
            zOpen = (const char*)(pFd->zDel = zCopy);
          }else{
................................................................................
    rbuVfsCurrentTime,            /* xCurrentTime */
    rbuVfsGetLastError,           /* xGetLastError */
    0,                            /* xCurrentTimeInt64 (version 2) */
    0, 0, 0                       /* Unimplemented version 3 methods */
  };

  rbu_vfs *pNew = 0;              /* Newly allocated VFS */
  int nName;
  int rc = SQLITE_OK;



  int nByte;
  nName = strlen(zName);
  nByte = sizeof(rbu_vfs) + nName + 1;
  pNew = (rbu_vfs*)sqlite3_malloc(nByte);
  if( pNew==0 ){
    rc = SQLITE_NOMEM;
  }else{
    sqlite3_vfs *pParent;           /* Parent VFS */
    memset(pNew, 0, nByte);
    pParent = sqlite3_vfs_find(zParent);
    if( pParent==0 ){
................................................................................
  char **pzErr
){
  StatTable *pTab = 0;
  int rc = SQLITE_OK;
  int iDb;

  if( argc>=4 ){


    iDb = sqlite3FindDbName(db, argv[3]);
    if( iDb<0 ){
      *pzErr = sqlite3_mprintf("no such database: %s", argv[3]);
      return SQLITE_ERROR;
    }
  }else{
    iDb = 0;
  }
................................................................................
#endif
SQLITE_EXTENSION_INIT1
/* #include <assert.h> */
/* #include <string.h> */
/* #include <stdlib.h> */
/* #include <stdarg.h> */




#define UNUSED_PARAM(X)  (void)(X)


#ifndef LARGEST_INT64
# define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
#endif

/*
................................................................................
** string.
*/
static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
  u32 i;
  if( (N+p->nUsed+2 >= p->nAlloc) && jsonGrow(p,N+2)!=0 ) return;
  p->zBuf[p->nUsed++] = '"';
  for(i=0; i<N; i++){
    char c = zIn[i];
    if( c=='"' || c=='\\' ){

      if( (p->nUsed+N+3-i > p->nAlloc) && jsonGrow(p,N+3-i)!=0 ) return;
      p->zBuf[p->nUsed++] = '\\';






















    }
    p->zBuf[p->nUsed++] = c;
  }
  p->zBuf[p->nUsed++] = '"';
  assert( p->nUsed<p->nAlloc );
}

................................................................................
        jsonAppendString(p, z, n);
      }
      break;
    }
    default: {
      if( p->bErr==0 ){
        sqlite3_result_error(p->pCtx, "JSON cannot hold BLOB values", -1);
        p->bErr = 1;
        jsonReset(p);
      }
      break;
    }
  }
}

................................................................................
*/
static void jsonArrayStep(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonString *pStr;

  pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));
  if( pStr ){
    if( pStr->zBuf==0 ){
      jsonInit(pStr, ctx);
      jsonAppendChar(pStr, '[');
    }else{
      jsonAppendChar(pStr, ',');
................................................................................
static void jsonArrayFinal(sqlite3_context *ctx){
  JsonString *pStr;
  pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);
  if( pStr ){
    pStr->pCtx = ctx;
    jsonAppendChar(pStr, ']');
    if( pStr->bErr ){
      sqlite3_result_error_nomem(ctx);
      assert( pStr->bStatic );
    }else{
      sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed,
                          pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);
      pStr->bStatic = 1;
    }
  }else{
................................................................................
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonString *pStr;
  const char *z;
  u32 n;

  pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));
  if( pStr ){
    if( pStr->zBuf==0 ){
      jsonInit(pStr, ctx);
      jsonAppendChar(pStr, '{');
    }else{
      jsonAppendChar(pStr, ',');
................................................................................
}
static void jsonObjectFinal(sqlite3_context *ctx){
  JsonString *pStr;
  pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);
  if( pStr ){
    jsonAppendChar(pStr, '}');
    if( pStr->bErr ){
      sqlite3_result_error_nomem(ctx);
      assert( pStr->bStatic );
    }else{
      sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed,
                          pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);
      pStr->bStatic = 1;
    }
  }else{
................................................................................
**   *pnToken to the number of tokens in column iCol of the current row.
**
**   If parameter iCol is greater than or equal to the number of columns
**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
**   an OOM condition or IO error), an appropriate SQLite error code is 
**   returned.
**



** xColumnText:
**   This function attempts to retrieve the text of column iCol of the
**   current document. If successful, (*pz) is set to point to a buffer
**   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
**   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
**   if an error occurs, an SQLite error code is returned and the final values
**   of (*pz) and (*pn) are undefined.
................................................................................
**   are numbered starting from zero.
**
** xInstCount:
**   Set *pnInst to the total number of occurrences of all phrases within
**   the query within the current row. Return SQLITE_OK if successful, or
**   an error code (i.e. SQLITE_NOMEM) if an error occurs.
**





** xInst:
**   Query for the details of phrase match iIdx within the current row.
**   Phrase matches are numbered starting from zero, so the iIdx argument
**   should be greater than or equal to zero and smaller than the value
**   output by xInstCount().






**
**   Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 
**   if an error occurs.



**
** xRowid:
**   Returns the rowid of the current row.
**
** xTokenize:
**   Tokenize text using the tokenizer belonging to the FTS5 table.
**
................................................................................
**   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
**   to use, this API may be faster under some circumstances. To iterate 
**   through instances of phrase iPhrase, use the following code:
**
**       Fts5PhraseIter iter;
**       int iCol, iOff;
**       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
**           iOff>=0;
**           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
**       ){
**         // An instance of phrase iPhrase at offset iOff of column iCol
**       }
**
**   The Fts5PhraseIter structure is defined above. Applications should not
**   modify this structure directly - it should only be used as shown above
**   with the xPhraseFirst() and xPhraseNext() API methods.

**






** xPhraseNext()
**   See xPhraseFirst above.































*/
struct Fts5ExtensionApi {
  int iVersion;                   /* Currently always set to 1 */

  void *(*xUserData)(Fts5Context*);

  int (*xColumnCount)(Fts5Context*);
  int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
  int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);

................................................................................

  int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
    int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
  );
  int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
  void *(*xGetAuxdata)(Fts5Context*, int bClear);

  void (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
  void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);



};

/* 
** CUSTOM AUXILIARY FUNCTIONS
*************************************************************************/

/*************************************************************************
................................................................................
/* #include <assert.h> */

#ifndef SQLITE_AMALGAMATION

typedef unsigned char  u8;
typedef unsigned int   u32;
typedef unsigned short u16;

typedef sqlite3_int64 i64;
typedef sqlite3_uint64 u64;

#define ArraySize(x) (sizeof(x) / sizeof(x[0]))

#define testcase(x)
#define ALWAYS(x) 1
#define NEVER(x) 0

#define MIN(x,y) (((x) < (y)) ? (x) : (y))
#define MAX(x,y) (((x) > (y)) ? (x) : (y))
................................................................................
*/
#ifdef SQLITE_DEBUG
SQLITE_API extern int sqlite3_fts5_may_be_corrupt;
# define assert_nc(x) assert(sqlite3_fts5_may_be_corrupt || (x))
#else
# define assert_nc(x) assert(x)
#endif











typedef struct Fts5Global Fts5Global;
typedef struct Fts5Colset Fts5Colset;

/* If a NEAR() clump or phrase may only match a specific set of columns, 
** then an object of the following type is used to record the set of columns.
** Each entry in the aiCol[] array is a column that may be matched.
................................................................................
  u8 *abUnindexed;                /* True for unindexed columns */
  int nPrefix;                    /* Number of prefix indexes */
  int *aPrefix;                   /* Sizes in bytes of nPrefix prefix indexes */
  int eContent;                   /* An FTS5_CONTENT value */
  char *zContent;                 /* content table */ 
  char *zContentRowid;            /* "content_rowid=" option value */ 
  int bColumnsize;                /* "columnsize=" option value (dflt==1) */

  char *zContentExprlist;
  Fts5Tokenizer *pTok;
  fts5_tokenizer *pTokApi;

  /* Values loaded from the %_config table */
  int iCookie;                    /* Incremented when %_config is modified */
  int pgsz;                       /* Approximate page size used in %_data */
................................................................................
/* Current expected value of %_config table 'version' field */
#define FTS5_CURRENT_VERSION 4

#define FTS5_CONTENT_NORMAL   0
#define FTS5_CONTENT_NONE     1
#define FTS5_CONTENT_EXTERNAL 2







static int sqlite3Fts5ConfigParse(
    Fts5Global*, sqlite3*, int, const char **, Fts5Config**, char**
);
static void sqlite3Fts5ConfigFree(Fts5Config*);
................................................................................
typedef struct Fts5Buffer Fts5Buffer;
struct Fts5Buffer {
  u8 *p;
  int n;
  int nSpace;
};

static int sqlite3Fts5BufferSize(int*, Fts5Buffer*, int);
static void sqlite3Fts5BufferAppendVarint(int*, Fts5Buffer*, i64);
static void sqlite3Fts5BufferAppendBlob(int*, Fts5Buffer*, int, const u8*);
static void sqlite3Fts5BufferAppendString(int *, Fts5Buffer*, const char*);
static void sqlite3Fts5BufferFree(Fts5Buffer*);
static void sqlite3Fts5BufferZero(Fts5Buffer*);
static void sqlite3Fts5BufferSet(int*, Fts5Buffer*, int, const u8*);
static void sqlite3Fts5BufferAppendPrintf(int *, Fts5Buffer*, char *zFmt, ...);

static char *sqlite3Fts5Mprintf(int *pRc, const char *zFmt, ...);
................................................................................
#define fts5BufferZero(x)             sqlite3Fts5BufferZero(x)
#define fts5BufferAppendVarint(a,b,c) sqlite3Fts5BufferAppendVarint(a,b,c)
#define fts5BufferFree(a)             sqlite3Fts5BufferFree(a)
#define fts5BufferAppendBlob(a,b,c,d) sqlite3Fts5BufferAppendBlob(a,b,c,d)
#define fts5BufferSet(a,b,c,d)        sqlite3Fts5BufferSet(a,b,c,d)

#define fts5BufferGrow(pRc,pBuf,nn) ( \
  (pBuf)->n + (nn) <= (pBuf)->nSpace ? 0 : \
    sqlite3Fts5BufferSize((pRc),(pBuf),(nn)+(pBuf)->n) \
)

/* Write and decode big-endian 32-bit integer values */
static void sqlite3Fts5Put32(u8*, int);
static int sqlite3Fts5Get32(const u8*);

................................................................................
static int sqlite3Fts5PoslistReaderNext(Fts5PoslistReader*);

typedef struct Fts5PoslistWriter Fts5PoslistWriter;
struct Fts5PoslistWriter {
  i64 iPrev;
};
static int sqlite3Fts5PoslistWriterAppend(Fts5Buffer*, Fts5PoslistWriter*, i64);


static int sqlite3Fts5PoslistNext64(
  const u8 *a, int n,             /* Buffer containing poslist */
  int *pi,                        /* IN/OUT: Offset within a[] */
  i64 *piOff                      /* IN/OUT: Current offset */
);

................................................................................
/* Malloc utility */
static void *sqlite3Fts5MallocZero(int *pRc, int nByte);
static char *sqlite3Fts5Strndup(int *pRc, const char *pIn, int nIn);

/* Character set tests (like isspace(), isalpha() etc.) */
static int sqlite3Fts5IsBareword(char t);








/*
** End of interface to code in fts5_buffer.c.
**************************************************************************/

/**************************************************************************
** Interface to code in fts5_index.c. fts5_index.c contains contains code
** to access the data stored in the %_data table.
*/

typedef struct Fts5Index Fts5Index;
typedef struct Fts5IndexIter Fts5IndexIter;










/*
** Values used as part of the flags argument passed to IndexQuery().
*/
#define FTS5INDEX_QUERY_PREFIX     0x0001   /* Prefix query */
#define FTS5INDEX_QUERY_DESC       0x0002   /* Docs in descending rowid order */
#define FTS5INDEX_QUERY_TEST_NOIDX 0x0004   /* Do not use prefix index */
#define FTS5INDEX_QUERY_SCAN       0x0008   /* Scan query (fts5vocab) */







/*
** Create/destroy an Fts5Index object.
*/
static int sqlite3Fts5IndexOpen(Fts5Config *pConfig, int bCreate, Fts5Index**, char**);
static int sqlite3Fts5IndexClose(Fts5Index *p);

/*
** for(
**   sqlite3Fts5IndexQuery(p, "token", 5, 0, 0, &pIter);
**   0==sqlite3Fts5IterEof(pIter);
**   sqlite3Fts5IterNext(pIter)

** ){
**   i64 iRowid = sqlite3Fts5IterRowid(pIter);
** }








*/






/*
** Open a new iterator to iterate though all rowids that match the 
** specified token or token prefix.
*/
static int sqlite3Fts5IndexQuery(
  Fts5Index *p,                   /* FTS index to query */
................................................................................
  Fts5IndexIter **ppIter          /* OUT: New iterator object */
);

/*
** The various operations on open token or token prefix iterators opened
** using sqlite3Fts5IndexQuery().
*/
static int sqlite3Fts5IterEof(Fts5IndexIter*);
static int sqlite3Fts5IterNext(Fts5IndexIter*);
static int sqlite3Fts5IterNextFrom(Fts5IndexIter*, i64 iMatch);
static i64 sqlite3Fts5IterRowid(Fts5IndexIter*);
static int sqlite3Fts5IterPoslist(Fts5IndexIter*,Fts5Colset*, const u8**, int*, i64*);
static int sqlite3Fts5IterPoslistBuffer(Fts5IndexIter *pIter, Fts5Buffer *pBuf);

/*
** Close an iterator opened by sqlite3Fts5IndexQuery().
*/
static void sqlite3Fts5IterClose(Fts5IndexIter*);

/*
................................................................................
*/
static int sqlite3Fts5IndexGetAverages(Fts5Index *p, i64 *pnRow, i64 *anSize);
static int sqlite3Fts5IndexSetAverages(Fts5Index *p, const u8*, int);

/*
** Functions called by the storage module as part of integrity-check.
*/
static u64 sqlite3Fts5IndexCksum(Fts5Config*,i64,int,int,const char*,int);
static int sqlite3Fts5IndexIntegrityCheck(Fts5Index*, u64 cksum);

/* 
** Called during virtual module initialization to register UDF 
** fts5_decode() with SQLite 
*/
static int sqlite3Fts5IndexInit(sqlite3*);
................................................................................
** Interface to code in fts5_hash.c. 
*/
typedef struct Fts5Hash Fts5Hash;

/*
** Create a hash table, free a hash table.
*/
static int sqlite3Fts5HashNew(Fts5Hash**, int *pnSize);
static void sqlite3Fts5HashFree(Fts5Hash*);

static int sqlite3Fts5HashWrite(
  Fts5Hash*,
  i64 iRowid,                     /* Rowid for this entry */
  int iCol,                       /* Column token appears in (-ve -> delete) */
  int iPos,                       /* Position of token within column */
................................................................................
static int sqlite3Fts5StorageOpen(Fts5Config*, Fts5Index*, int, Fts5Storage**, char**);
static int sqlite3Fts5StorageClose(Fts5Storage *p);
static int sqlite3Fts5StorageRename(Fts5Storage*, const char *zName);

static int sqlite3Fts5DropAll(Fts5Config*);
static int sqlite3Fts5CreateTable(Fts5Config*, const char*, const char*, int, char **);

static int sqlite3Fts5StorageDelete(Fts5Storage *p, i64);
static int sqlite3Fts5StorageContentInsert(Fts5Storage *p, sqlite3_value**, i64*);
static int sqlite3Fts5StorageIndexInsert(Fts5Storage *p, sqlite3_value**, i64);

static int sqlite3Fts5StorageIntegrity(Fts5Storage *p);

static int sqlite3Fts5StorageStmt(Fts5Storage *p, int eStmt, sqlite3_stmt**, char**);
static void sqlite3Fts5StorageStmtRelease(Fts5Storage *p, int eStmt, sqlite3_stmt*);
................................................................................
static int sqlite3Fts5StorageSync(Fts5Storage *p, int bCommit);
static int sqlite3Fts5StorageRollback(Fts5Storage *p);

static int sqlite3Fts5StorageConfigValue(
    Fts5Storage *p, const char*, sqlite3_value*, int
);

static int sqlite3Fts5StorageSpecialDelete(Fts5Storage *p, i64 iDel, sqlite3_value**);

static int sqlite3Fts5StorageDeleteAll(Fts5Storage *p);
static int sqlite3Fts5StorageRebuild(Fts5Storage *p);
static int sqlite3Fts5StorageOptimize(Fts5Storage *p);
static int sqlite3Fts5StorageMerge(Fts5Storage *p, int nMerge);

/*
** End of interface to code in fts5_storage.c.
................................................................................
/* Called during startup to register a UDF with SQLite */
static int sqlite3Fts5ExprInit(Fts5Global*, sqlite3*);

static int sqlite3Fts5ExprPhraseCount(Fts5Expr*);
static int sqlite3Fts5ExprPhraseSize(Fts5Expr*, int iPhrase);
static int sqlite3Fts5ExprPoslist(Fts5Expr*, int, const u8 **);









static int sqlite3Fts5ExprClonePhrase(Fts5Config*, Fts5Expr*, int, Fts5Expr**);



/*******************************************
** The fts5_expr.c API above this point is used by the other hand-written
** C code in this module. The interfaces below this point are called by
** the parser code in fts5parse.y.  */

static void sqlite3Fts5ParseError(Fts5Parse *pParse, const char *zFmt, ...);
................................................................................
   }
#endif
   while( fts5yypParser->fts5yyidx>=0 ) fts5yy_pop_parser_stack(fts5yypParser);
   /* Here code is inserted which will execute if the parser
   ** stack every overflows */
/******** Begin %stack_overflow code ******************************************/

  assert( 0 );

/******** End %stack_overflow code ********************************************/
   sqlite3Fts5ParserARG_STORE; /* Suppress warning about unused %extra_argument var */
}

/*
** Print tracing information for a SHIFT action
*/
................................................................................
  int fts5yymajor,                   /* The major type of the error token */
  fts5YYMINORTYPE fts5yyminor            /* The minor type of the error token */
){
  sqlite3Fts5ParserARG_FETCH;
#define FTS5TOKEN (fts5yyminor.fts5yy0)
/************ Begin %syntax_error code ****************************************/


  sqlite3Fts5ParseError(
    pParse, "fts5: syntax error near \"%.*s\"",FTS5TOKEN.n,FTS5TOKEN.p
  );
/************ End %syntax_error code ******************************************/
  sqlite3Fts5ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
}

................................................................................
  int nToken,                     /* Size of token in bytes */
  int iStartOff,                  /* Start offset of token */
  int iEndOff                     /* End offset of token */
){
  HighlightContext *p = (HighlightContext*)pContext;
  int rc = SQLITE_OK;
  int iPos;



  if( tflags & FTS5_TOKEN_COLOCATED ) return SQLITE_OK;
  iPos = p->iPos++;

  if( p->iRangeEnd>0 ){
    if( iPos<p->iRangeStart || iPos>p->iRangeEnd ) return SQLITE_OK;
    if( p->iRangeStart && iPos==p->iRangeStart ) p->iOff = iStartOff;
................................................................................
*/
static int fts5CountCb(
  const Fts5ExtensionApi *pApi, 
  Fts5Context *pFts,
  void *pUserData                 /* Pointer to sqlite3_int64 variable */
){
  sqlite3_int64 *pn = (sqlite3_int64*)pUserData;

  (*pn)++;
  return SQLITE_OK;
}

/*
** Set *ppData to point to the Fts5Bm25Data object for the current query. 
** If the object has not already been allocated, allocate and populate it
................................................................................
    { "snippet",   0, fts5SnippetFunction, 0 },
    { "highlight", 0, fts5HighlightFunction, 0 },
    { "bm25",      0, fts5Bm25Function,    0 },
  };
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* To iterate through builtin functions */

  for(i=0; rc==SQLITE_OK && i<(int)ArraySize(aBuiltin); i++){
    rc = pApi->xCreateFunction(pApi,
        aBuiltin[i].zFunc,
        aBuiltin[i].pUserData,
        aBuiltin[i].xFunc,
        aBuiltin[i].xDestroy
    );
  }
................................................................................
******************************************************************************
*/



/* #include "fts5Int.h" */

static int sqlite3Fts5BufferSize(int *pRc, Fts5Buffer *pBuf, int nByte){

  int nNew = pBuf->nSpace ? pBuf->nSpace*2 : 64;
  u8 *pNew;
  while( nNew<nByte ){
    nNew = nNew * 2;
  }
  pNew = sqlite3_realloc(pBuf->p, nNew);
  if( pNew==0 ){
    *pRc = SQLITE_NOMEM;
    return 1;
  }else{
    pBuf->nSpace = nNew;
    pBuf->p = pNew;

  }
  return 0;
}


/*
** Encode value iVal as an SQLite varint and append it to the buffer object
................................................................................
** Append buffer nData/pData to buffer pBuf. If an OOM error occurs, set 
** the error code in p. If an error has already occurred when this function
** is called, it is a no-op.
*/
static void sqlite3Fts5BufferAppendBlob(
  int *pRc,
  Fts5Buffer *pBuf, 
  int nData, 
  const u8 *pData
){
  assert( *pRc || nData>=0 );
  if( fts5BufferGrow(pRc, pBuf, nData) ) return;
  memcpy(&pBuf->p[pBuf->n], pData, nData);
  pBuf->n += nData;
}

/*
** Append the nul-terminated string zStr to the buffer pBuf. This function
................................................................................
){
  memset(pIter, 0, sizeof(*pIter));
  pIter->a = a;
  pIter->n = n;
  sqlite3Fts5PoslistReaderNext(pIter);
  return pIter->bEof;
}






















static int sqlite3Fts5PoslistWriterAppend(
  Fts5Buffer *pBuf, 
  Fts5PoslistWriter *pWriter,
  i64 iPos
){
  static const i64 colmask = ((i64)(0x7FFFFFFF)) << 32;
  int rc = SQLITE_OK;
  if( 0==fts5BufferGrow(&rc, pBuf, 5+5+5) ){
    if( (iPos & colmask) != (pWriter->iPrev & colmask) ){
      pBuf->p[pBuf->n++] = 1;
      pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], (iPos>>32));
      pWriter->iPrev = (iPos & colmask);
    }
    pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], (iPos-pWriter->iPrev)+2);
    pWriter->iPrev = iPos;
  }

  return rc;
}

static void *sqlite3Fts5MallocZero(int *pRc, int nByte){
  void *pRet = 0;
  if( *pRc==SQLITE_OK ){
    pRet = sqlite3_malloc(nByte);
    if( pRet==0 && nByte>0 ){
................................................................................
    1, 1, 1, 1, 1, 1, 1, 1,    1, 1, 1, 0, 0, 0, 0, 0    /* 0x70 .. 0x7F */
  };

  return (t & 0x80) || aBareword[(int)t];
}






















































































/*
** 2014 Jun 09
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
................................................................................
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This is an SQLite module implementing full-text search.
*/



/* #include "fts5Int.h" */

#define FTS5_DEFAULT_PAGE_SIZE   4050
#define FTS5_DEFAULT_AUTOMERGE      4
#define FTS5_DEFAULT_CRISISMERGE   16
................................................................................
  assert( 0==fts5_iswhitespace(z[0]) );
  quote = z[0];
  if( quote=='[' || quote=='\'' || quote=='"' || quote=='`' ){
    fts5Dequote(z);
  }
}




























/*
** Parse a "special" CREATE VIRTUAL TABLE directive and update
** configuration object pConfig as appropriate.
**
** If successful, object pConfig is updated and SQLITE_OK returned. If
** an error occurs, an SQLite error code is returned and an error message
** may be left in *pzErr. It is the responsibility of the caller to
................................................................................
      }

      while( p[0]>='0' && p[0]<='9' && nPre<1000 ){
        nPre = nPre*10 + (p[0] - '0');
        p++;
      }

      if( rc==SQLITE_OK && (nPre<=0 || nPre>=1000) ){
        *pzErr = sqlite3_mprintf("prefix length out of range (max 999)");
        rc = SQLITE_ERROR;
        break;
      }

      pConfig->aPrefix[pConfig->nPrefix] = nPre;
      pConfig->nPrefix++;
................................................................................
      *pzErr = sqlite3_mprintf("malformed columnsize=... directive");
      rc = SQLITE_ERROR;
    }else{
      pConfig->bColumnsize = (zArg[0]=='1');
    }
    return rc;
  }















  *pzErr = sqlite3_mprintf("unrecognized option: \"%.*s\"", nCmd, zCmd);
  return SQLITE_ERROR;
}

/*
** Allocate an instance of the default tokenizer ("simple") at 
................................................................................

  nByte = nArg * (sizeof(char*) + sizeof(u8));
  pRet->azCol = (char**)sqlite3Fts5MallocZero(&rc, nByte);
  pRet->abUnindexed = (u8*)&pRet->azCol[nArg];
  pRet->zDb = sqlite3Fts5Strndup(&rc, azArg[1], -1);
  pRet->zName = sqlite3Fts5Strndup(&rc, azArg[2], -1);
  pRet->bColumnsize = 1;

#ifdef SQLITE_DEBUG
  pRet->bPrefixIndex = 1;
#endif
  if( rc==SQLITE_OK && sqlite3_stricmp(pRet->zName, FTS5_RANK_NAME)==0 ){
    *pzErr = sqlite3_mprintf("reserved fts5 table name: %s", pRet->zName);
    rc = SQLITE_ERROR;
  }
................................................................................

  if( rc==SQLITE_OK ){
    pConfig->iCookie = iCookie;
  }
  return rc;
}


/*
** 2014 May 31
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
................................................................................
/* #include <stdio.h> */
static void sqlite3Fts5ParserTrace(FILE*, char*);
#endif


struct Fts5Expr {
  Fts5Index *pIndex;

  Fts5ExprNode *pRoot;
  int bDesc;                      /* Iterate in descending rowid order */
  int nPhrase;                    /* Number of phrases in expression */
  Fts5ExprPhrase **apExprPhrase;  /* Pointers to phrase objects */
};

/*
................................................................................
**       FTS5_TERM                (pNear valid)
*/
struct Fts5ExprNode {
  int eType;                      /* Node type */
  int bEof;                       /* True at EOF */
  int bNomatch;                   /* True if entry is not a match */




  i64 iRowid;                     /* Current rowid */
  Fts5ExprNearset *pNear;         /* For FTS5_STRING - cluster of phrases */

  /* Child nodes. For a NOT node, this array always contains 2 entries. For 
  ** AND or OR nodes, it contains 2 or more entries.  */
  int nChild;                     /* Number of child nodes */
  Fts5ExprNode *apChild[1];       /* Array of child nodes */
};

#define Fts5NodeIsString(p) ((p)->eType==FTS5_TERM || (p)->eType==FTS5_STRING)







/*
** An instance of the following structure represents a single search term
** or term prefix.
*/
struct Fts5ExprTerm {
  int bPrefix;                    /* True for a prefix term */
  char *zTerm;                    /* nul-terminated term */
................................................................................
  assert( sParse.rc!=SQLITE_OK || sParse.zErr==0 );
  if( sParse.rc==SQLITE_OK ){
    *ppNew = pNew = sqlite3_malloc(sizeof(Fts5Expr));
    if( pNew==0 ){
      sParse.rc = SQLITE_NOMEM;
      sqlite3Fts5ParseNodeFree(sParse.pExpr);
    }else{







      pNew->pRoot = sParse.pExpr;

      pNew->pIndex = 0;

      pNew->apExprPhrase = sParse.apPhrase;
      pNew->nPhrase = sParse.nPhrase;
      sParse.apPhrase = 0;
    }
  }

  sqlite3_free(sParse.apPhrase);
................................................................................
  int bRetValid = 0;
  Fts5ExprTerm *p;

  assert( pTerm->pSynonym );
  assert( bDesc==0 || bDesc==1 );
  for(p=pTerm; p; p=p->pSynonym){
    if( 0==sqlite3Fts5IterEof(p->pIter) ){
      i64 iRowid = sqlite3Fts5IterRowid(p->pIter);
      if( bRetValid==0 || (bDesc!=(iRowid<iRet)) ){
        iRet = iRowid;
        bRetValid = 1;
      }
    }
  }

................................................................................
  if( pbEof && bRetValid==0 ) *pbEof = 1;
  return iRet;
}

/*
** Argument pTerm must be a synonym iterator.
*/
static int fts5ExprSynonymPoslist(
  Fts5ExprTerm *pTerm, 
  Fts5Colset *pColset,
  i64 iRowid,
  int *pbDel,                     /* OUT: Caller should sqlite3_free(*pa) */

  u8 **pa, int *pn
){
  Fts5PoslistReader aStatic[4];
  Fts5PoslistReader *aIter = aStatic;
  int nIter = 0;
  int nAlloc = 4;
  int rc = SQLITE_OK;
  Fts5ExprTerm *p;

  assert( pTerm->pSynonym );
  for(p=pTerm; p; p=p->pSynonym){
    Fts5IndexIter *pIter = p->pIter;
    if( sqlite3Fts5IterEof(pIter)==0 && sqlite3Fts5IterRowid(pIter)==iRowid ){
      const u8 *a;
      int n;
      i64 dummy;
      rc = sqlite3Fts5IterPoslist(pIter, pColset, &a, &n, &dummy);
      if( rc!=SQLITE_OK ) goto synonym_poslist_out;
      if( nIter==nAlloc ){
        int nByte = sizeof(Fts5PoslistReader) * nAlloc * 2;
        Fts5PoslistReader *aNew = (Fts5PoslistReader*)sqlite3_malloc(nByte);
        if( aNew==0 ){
          rc = SQLITE_NOMEM;
          goto synonym_poslist_out;
        }
        memcpy(aNew, aIter, sizeof(Fts5PoslistReader) * nIter);
        nAlloc = nAlloc*2;
        if( aIter!=aStatic ) sqlite3_free(aIter);
        aIter = aNew;
      }
      sqlite3Fts5PoslistReaderInit(a, n, &aIter[nIter]);
      assert( aIter[nIter].bEof==0 );
      nIter++;
    }
  }

  assert( *pbDel==0 );
  if( nIter==1 ){
    *pa = (u8*)aIter[0].a;
    *pn = aIter[0].n;
  }else{
    Fts5PoslistWriter writer = {0};
    Fts5Buffer buf = {0,0,0};
    i64 iPrev = -1;

    while( 1 ){
      int i;
      i64 iMin = FTS5_LARGEST_INT64;
      for(i=0; i<nIter; i++){
        if( aIter[i].bEof==0 ){
          if( aIter[i].iPos==iPrev ){
            if( sqlite3Fts5PoslistReaderNext(&aIter[i]) ) continue;
................................................................................
          }
          if( aIter[i].iPos<iMin ){
            iMin = aIter[i].iPos;
          }
        }
      }
      if( iMin==FTS5_LARGEST_INT64 || rc!=SQLITE_OK ) break;
      rc = sqlite3Fts5PoslistWriterAppend(&buf, &writer, iMin);
      iPrev = iMin;
    }
    if( rc ){
      sqlite3_free(buf.p);
    }else{
      *pa = buf.p;
      *pn = buf.n;
      *pbDel = 1;
    }
  }

 synonym_poslist_out:
  if( aIter!=aStatic ) sqlite3_free(aIter);
  return rc;
}
................................................................................
**
** SQLITE_OK is returned if an error occurs, or an SQLite error code 
** otherwise. It is not considered an error code if the current rowid is 
** not a match.
*/
static int fts5ExprPhraseIsMatch(
  Fts5ExprNode *pNode,            /* Node pPhrase belongs to */
  Fts5Colset *pColset,            /* Restrict matches to these columns */
  Fts5ExprPhrase *pPhrase,        /* Phrase object to initialize */
  int *pbMatch                    /* OUT: Set to true if really a match */
){
  Fts5PoslistWriter writer = {0};
  Fts5PoslistReader aStatic[4];
  Fts5PoslistReader *aIter = aStatic;
  int i;
  int rc = SQLITE_OK;
  
  fts5BufferZero(&pPhrase->poslist);

  /* If the aStatic[] array is not large enough, allocate a large array
  ** using sqlite3_malloc(). This approach could be improved upon. */
  if( pPhrase->nTerm>(int)ArraySize(aStatic) ){
    int nByte = sizeof(Fts5PoslistReader) * pPhrase->nTerm;
    aIter = (Fts5PoslistReader*)sqlite3_malloc(nByte);
    if( !aIter ) return SQLITE_NOMEM;
  }
  memset(aIter, 0, sizeof(Fts5PoslistReader) * pPhrase->nTerm);

  /* Initialize a term iterator for each term in the phrase */
  for(i=0; i<pPhrase->nTerm; i++){
    Fts5ExprTerm *pTerm = &pPhrase->aTerm[i];
    i64 dummy;
    int n = 0;
    int bFlag = 0;
    const u8 *a = 0;
    if( pTerm->pSynonym ){

      rc = fts5ExprSynonymPoslist(
          pTerm, pColset, pNode->iRowid, &bFlag, (u8**)&a, &n
      );



    }else{
      rc = sqlite3Fts5IterPoslist(pTerm->pIter, pColset, &a, &n, &dummy);


    }
    if( rc!=SQLITE_OK ) goto ismatch_out;
    sqlite3Fts5PoslistReaderInit(a, n, &aIter[i]);
    aIter[i].bFlag = (u8)bFlag;
    if( aIter[i].bEof ) goto ismatch_out;
  }

  while( 1 ){
    int bMatch;
................................................................................
  memset(p, 0, sizeof(Fts5LookaheadReader));
  p->a = a;
  p->n = n;
  fts5LookaheadReaderNext(p);
  return fts5LookaheadReaderNext(p);
}

#if 0
static int fts5LookaheadReaderEof(Fts5LookaheadReader *p){
  return (p->iPos==FTS5_LOOKAHEAD_EOF);
}
#endif

typedef struct Fts5NearTrimmer Fts5NearTrimmer;
struct Fts5NearTrimmer {
  Fts5LookaheadReader reader;     /* Input iterator */
  Fts5PoslistWriter writer;       /* Writer context */
  Fts5Buffer *pOut;               /* Output poslist */
};

................................................................................
  int rc = *pRc;
  int bMatch;

  assert( pNear->nPhrase>1 );

  /* If the aStatic[] array is not large enough, allocate a large array
  ** using sqlite3_malloc(). This approach could be improved upon. */
  if( pNear->nPhrase>(int)ArraySize(aStatic) ){
    int nByte = sizeof(Fts5NearTrimmer) * pNear->nPhrase;
    a = (Fts5NearTrimmer*)sqlite3Fts5MallocZero(&rc, nByte);
  }else{
    memset(aStatic, 0, sizeof(aStatic));
  }
  if( rc!=SQLITE_OK ){
    *pRc = rc;
................................................................................
    int bRet = a[0].pOut->n>0;
    *pRc = rc;
    if( a!=aStatic ) sqlite3_free(a);
    return bRet;
  }
}

/*
** Advance the first term iterator in the first phrase of pNear. Set output
** variable *pbEof to true if it reaches EOF or if an error occurs.
**
** Return SQLITE_OK if successful, or an SQLite error code if an error
** occurs.
*/
static int fts5ExprNearAdvanceFirst(
  Fts5Expr *pExpr,                /* Expression pPhrase belongs to */
  Fts5ExprNode *pNode,            /* FTS5_STRING or FTS5_TERM node */
  int bFromValid,
  i64 iFrom 
){
  Fts5ExprTerm *pTerm = &pNode->pNear->apPhrase[0]->aTerm[0];
  int rc = SQLITE_OK;

  if( pTerm->pSynonym ){
    int bEof = 1;
    Fts5ExprTerm *p;

    /* Find the firstest rowid any synonym points to. */
    i64 iRowid = fts5ExprSynonymRowid(pTerm, pExpr->bDesc, 0);

    /* Advance each iterator that currently points to iRowid. Or, if iFrom
    ** is valid - each iterator that points to a rowid before iFrom.  */
    for(p=pTerm; p; p=p->pSynonym){
      if( sqlite3Fts5IterEof(p->pIter)==0 ){
        i64 ii = sqlite3Fts5IterRowid(p->pIter);
        if( ii==iRowid 
         || (bFromValid && ii!=iFrom && (ii>iFrom)==pExpr->bDesc) 
        ){
          if( bFromValid ){
            rc = sqlite3Fts5IterNextFrom(p->pIter, iFrom);
          }else{
            rc = sqlite3Fts5IterNext(p->pIter);
          }
          if( rc!=SQLITE_OK ) break;
          if( sqlite3Fts5IterEof(p->pIter)==0 ){
            bEof = 0;
          }
        }else{
          bEof = 0;
        }
      }
    }

    /* Set the EOF flag if either all synonym iterators are at EOF or an
    ** error has occurred.  */
    pNode->bEof = (rc || bEof);
  }else{
    Fts5IndexIter *pIter = pTerm->pIter;

    assert( Fts5NodeIsString(pNode) );
    if( bFromValid ){
      rc = sqlite3Fts5IterNextFrom(pIter, iFrom);
    }else{
      rc = sqlite3Fts5IterNext(pIter);
    }

    pNode->bEof = (rc || sqlite3Fts5IterEof(pIter));
  }

  return rc;
}

/*
** Advance iterator pIter until it points to a value equal to or laster
** than the initial value of *piLast. If this means the iterator points
** to a value laster than *piLast, update *piLast to the new lastest value.
**
** If the iterator reaches EOF, set *pbEof to true before returning. If
** an error occurs, set *pRc to an error code. If either *pbEof or *pRc
................................................................................
  i64 *piLast,                    /* IN/OUT: Lastest rowid seen so far */
  int *pRc,                       /* OUT: Error code */
  int *pbEof                      /* OUT: Set to true if EOF */
){
  i64 iLast = *piLast;
  i64 iRowid;

  iRowid = sqlite3Fts5IterRowid(pIter);
  if( (bDesc==0 && iLast>iRowid) || (bDesc && iLast<iRowid) ){
    int rc = sqlite3Fts5IterNextFrom(pIter, iLast);
    if( rc || sqlite3Fts5IterEof(pIter) ){
      *pRc = rc;
      *pbEof = 1;
      return 1;
    }
    iRowid = sqlite3Fts5IterRowid(pIter);
    assert( (bDesc==0 && iRowid>=iLast) || (bDesc==1 && iRowid<=iLast) );
  }
  *piLast = iRowid;

  return 0;
}

................................................................................
  int rc = SQLITE_OK;
  i64 iLast = *piLast;
  Fts5ExprTerm *p;
  int bEof = 0;

  for(p=pTerm; rc==SQLITE_OK && p; p=p->pSynonym){
    if( sqlite3Fts5IterEof(p->pIter)==0 ){
      i64 iRowid = sqlite3Fts5IterRowid(p->pIter);
      if( (bDesc==0 && iLast>iRowid) || (bDesc && iLast<iRowid) ){
        rc = sqlite3Fts5IterNextFrom(p->pIter, iLast);
      }
    }
  }

  if( rc!=SQLITE_OK ){
................................................................................
static int fts5ExprNearTest(
  int *pRc,
  Fts5Expr *pExpr,                /* Expression that pNear is a part of */
  Fts5ExprNode *pNode             /* The "NEAR" node (FTS5_STRING) */
){
  Fts5ExprNearset *pNear = pNode->pNear;
  int rc = *pRc;















  int i;

  /* Check that each phrase in the nearset matches the current row.
  ** Populate the pPhrase->poslist buffers at the same time. If any
  ** phrase is not a match, break out of the loop early.  */
  for(i=0; rc==SQLITE_OK && i<pNear->nPhrase; i++){
    Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
    if( pPhrase->nTerm>1 || pPhrase->aTerm[0].pSynonym || pNear->pColset ){
      int bMatch = 0;
      rc = fts5ExprPhraseIsMatch(pNode, pNear->pColset, pPhrase, &bMatch);
      if( bMatch==0 ) break;
    }else{
      rc = sqlite3Fts5IterPoslistBuffer(
          pPhrase->aTerm[0].pIter, &pPhrase->poslist
      );

    }
  }

  *pRc = rc;
  if( i==pNear->nPhrase && (i==1 || fts5ExprNearIsMatch(pRc, pNear)) ){
    return 1;
  }

  return 0;
}

static int fts5ExprTokenTest(
  Fts5Expr *pExpr,                /* Expression that pNear is a part of */
  Fts5ExprNode *pNode             /* The "NEAR" node (FTS5_TERM) */
){
  /* As this "NEAR" object is actually a single phrase that consists 
  ** of a single term only, grab pointers into the poslist managed by the
  ** fts5_index.c iterator object. This is much faster than synthesizing 
  ** a new poslist the way we have to for more complicated phrase or NEAR
  ** expressions.  */
  Fts5ExprNearset *pNear = pNode->pNear;
  Fts5ExprPhrase *pPhrase = pNear->apPhrase[0];
  Fts5IndexIter *pIter = pPhrase->aTerm[0].pIter;
  Fts5Colset *pColset = pNear->pColset;
  int rc;

  assert( pNode->eType==FTS5_TERM );
  assert( pNear->nPhrase==1 && pPhrase->nTerm==1 );
  assert( pPhrase->aTerm[0].pSynonym==0 );

  rc = sqlite3Fts5IterPoslist(pIter, pColset, 
      (const u8**)&pPhrase->poslist.p, &pPhrase->poslist.n, &pNode->iRowid
  );
  pNode->bNomatch = (pPhrase->poslist.n==0);
  return rc;
}

/*
** All individual term iterators in pNear are guaranteed to be valid when
** this function is called. This function checks if all term iterators
** point to the same rowid, and if not, advances them until they do.
** If an EOF is reached before this happens, *pbEof is set to true before
** returning.
**
** SQLITE_OK is returned if an error occurs, or an SQLite error code 
** otherwise. It is not considered an error code if an iterator reaches
** EOF.
*/
static int fts5ExprNearNextMatch(
  Fts5Expr *pExpr,                /* Expression pPhrase belongs to */
  Fts5ExprNode *pNode
){
  Fts5ExprNearset *pNear = pNode->pNear;
  Fts5ExprPhrase *pLeft = pNear->apPhrase[0];
  int rc = SQLITE_OK;
  i64 iLast;                      /* Lastest rowid any iterator points to */
  int i, j;                       /* Phrase and token index, respectively */
  int bMatch;                     /* True if all terms are at the same rowid */
  const int bDesc = pExpr->bDesc;

  /* Check that this node should not be FTS5_TERM */
  assert( pNear->nPhrase>1 
       || pNear->apPhrase[0]->nTerm>1 
       || pNear->apPhrase[0]->aTerm[0].pSynonym
  );

  /* Initialize iLast, the "lastest" rowid any iterator points to. If the
  ** iterator skips through rowids in the default ascending order, this means
  ** the maximum rowid. Or, if the iterator is "ORDER BY rowid DESC", then it
  ** means the minimum rowid.  */
  if( pLeft->aTerm[0].pSynonym ){
    iLast = fts5ExprSynonymRowid(&pLeft->aTerm[0], bDesc, 0);
  }else{
    iLast = sqlite3Fts5IterRowid(pLeft->aTerm[0].pIter);
  }

  do {
    bMatch = 1;
    for(i=0; i<pNear->nPhrase; i++){
      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
      for(j=0; j<pPhrase->nTerm; j++){
        Fts5ExprTerm *pTerm = &pPhrase->aTerm[j];
        if( pTerm->pSynonym ){
          i64 iRowid = fts5ExprSynonymRowid(pTerm, bDesc, 0);
          if( iRowid==iLast ) continue;
          bMatch = 0;
          if( fts5ExprSynonymAdvanceto(pTerm, bDesc, &iLast, &rc) ){
            pNode->bEof = 1;
            return rc;
          }
        }else{
          Fts5IndexIter *pIter = pPhrase->aTerm[j].pIter;
          i64 iRowid = sqlite3Fts5IterRowid(pIter);
          if( iRowid==iLast ) continue;
          bMatch = 0;
          if( fts5ExprAdvanceto(pIter, bDesc, &iLast, &rc, &pNode->bEof) ){
            return rc;
          }
        }
      }
    }
  }while( bMatch==0 );

  pNode->iRowid = iLast;
  pNode->bNomatch = (0==fts5ExprNearTest(&rc, pExpr, pNode));

  return rc;
}

/*
** Initialize all term iterators in the pNear object. If any term is found
** to match no documents at all, return immediately without initializing any
** further iterators.
*/
static int fts5ExprNearInitAll(
................................................................................
  Fts5Expr *pExpr,
  Fts5ExprNode *pNode
){
  Fts5ExprNearset *pNear = pNode->pNear;
  int i, j;
  int rc = SQLITE_OK;


  for(i=0; rc==SQLITE_OK && i<pNear->nPhrase; i++){
    Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
    for(j=0; j<pPhrase->nTerm; j++){
      Fts5ExprTerm *pTerm = &pPhrase->aTerm[j];
      Fts5ExprTerm *p;
      int bEof = 1;

................................................................................
        return rc;
      }
    }
  }

  return rc;
}

/* fts5ExprNodeNext() calls fts5ExprNodeNextMatch(). And vice-versa. */
static int fts5ExprNodeNextMatch(Fts5Expr*, Fts5ExprNode*);


/*
** If pExpr is an ASC iterator, this function returns a value with the
** same sign as:
**
**   (iLhs - iRhs)
**
................................................................................
    return (iLhs < iRhs);
  }
}

static void fts5ExprSetEof(Fts5ExprNode *pNode){
  int i;
  pNode->bEof = 1;

  for(i=0; i<pNode->nChild; i++){
    fts5ExprSetEof(pNode->apChild[i]);
  }
}

static void fts5ExprNodeZeroPoslist(Fts5ExprNode *pNode){
  if( pNode->eType==FTS5_STRING || pNode->eType==FTS5_TERM ){
................................................................................
    for(i=0; i<pNode->nChild; i++){
      fts5ExprNodeZeroPoslist(pNode->apChild[i]);
    }
  }
}

















































































































































































































































static int fts5ExprNodeNext(Fts5Expr*, Fts5ExprNode*, int, i64);

























/*
** Argument pNode is an FTS5_AND node.
*/
static int fts5ExprAndNextRowid(
  Fts5Expr *pExpr,                /* Expression pPhrase belongs to */
  Fts5ExprNode *pAnd              /* FTS5_AND node to advance */
){
  int iChild;
  i64 iLast = pAnd->iRowid;
  int rc = SQLITE_OK;
  int bMatch;
................................................................................

  assert( pAnd->bEof==0 );
  do {
    pAnd->bNomatch = 0;
    bMatch = 1;
    for(iChild=0; iChild<pAnd->nChild; iChild++){
      Fts5ExprNode *pChild = pAnd->apChild[iChild];
      if( 0 && pChild->eType==FTS5_STRING ){
        /* TODO */
      }else{
        int cmp = fts5RowidCmp(pExpr, iLast, pChild->iRowid);
        if( cmp>0 ){
          /* Advance pChild until it points to iLast or laster */
          rc = fts5ExprNodeNext(pExpr, pChild, 1, iLast);
          if( rc!=SQLITE_OK ) return rc;
        }
      }

      /* If the child node is now at EOF, so is the parent AND node. Otherwise,
      ** the child node is guaranteed to have advanced at least as far as
      ** rowid iLast. So if it is not at exactly iLast, pChild->iRowid is the
      ** new lastest rowid seen so far.  */
      assert( pChild->bEof || fts5RowidCmp(pExpr, iLast, pChild->iRowid)<=0 );
................................................................................
  if( pAnd->bNomatch && pAnd!=pExpr->pRoot ){
    fts5ExprNodeZeroPoslist(pAnd);
  }
  pAnd->iRowid = iLast;
  return SQLITE_OK;
}


/*
** Compare the values currently indicated by the two nodes as follows:
**
**    res = (*p1) - (*p2)
**
** Nodes that point to values that come later in the iteration order are
** considered to be larger. Nodes at EOF are the largest of all.
**
** This means that if the iteration order is ASC, then numerically larger
** rowids are considered larger. Or if it is the default DESC, numerically
** smaller rowids are larger.
*/
static int fts5NodeCompare(
  Fts5Expr *pExpr,
  Fts5ExprNode *p1, 
  Fts5ExprNode *p2


){




  if( p2->bEof ) return -1;
  if( p1->bEof ) return +1;
  return fts5RowidCmp(pExpr, p1->iRowid, p2->iRowid);
}

/*
** Advance node iterator pNode, part of expression pExpr. If argument
** bFromValid is zero, then pNode is advanced exactly once. Or, if argument
** bFromValid is non-zero, then pNode is advanced until it is at or past
** rowid value iFrom. Whether "past" means "less than" or "greater than"
** depends on whether this is an ASC or DESC iterator.
*/
static int fts5ExprNodeNext(
  Fts5Expr *pExpr, 
  Fts5ExprNode *pNode,
  int bFromValid,
  i64 iFrom
){
  int rc = SQLITE_OK;




  if( pNode->bEof==0 ){
    switch( pNode->eType ){
      case FTS5_STRING: {
        rc = fts5ExprNearAdvanceFirst(pExpr, pNode, bFromValid, iFrom);
        break;
      };





      case FTS5_TERM: {
        Fts5IndexIter *pIter = pNode->pNear->apPhrase[0]->aTerm[0].pIter;
        if( bFromValid ){
          rc = sqlite3Fts5IterNextFrom(pIter, iFrom);
        }else{
          rc = sqlite3Fts5IterNext(pIter);



        }
        if( rc==SQLITE_OK && sqlite3Fts5IterEof(pIter)==0 ){
          assert( rc==SQLITE_OK );
          rc = fts5ExprTokenTest(pExpr, pNode);
        }else{
          pNode->bEof = 1;




        }
        return rc;
      };

      case FTS5_AND: {
        Fts5ExprNode *pLeft = pNode->apChild[0];
        rc = fts5ExprNodeNext(pExpr, pLeft, bFromValid, iFrom);
        break;
      }

      case FTS5_OR: {
        int i;
        i64 iLast = pNode->iRowid;

        for(i=0; rc==SQLITE_OK && i<pNode->nChild; i++){


          Fts5ExprNode *p1 = pNode->apChild[i];
          assert( p1->bEof || fts5RowidCmp(pExpr, p1->iRowid, iLast)>=0 );
          if( p1->bEof==0 ){
            if( (p1->iRowid==iLast) 
             || (bFromValid && fts5RowidCmp(pExpr, p1->iRowid, iFrom)<0)


            ){
              rc = fts5ExprNodeNext(pExpr, p1, bFromValid, iFrom);
            }
          }
        }

        break;
      }

      default: assert( pNode->eType==FTS5_NOT ); {
        assert( pNode->nChild==2 );
        rc = fts5ExprNodeNext(pExpr, pNode->apChild[0], bFromValid, iFrom);
        break;
      }
    }

    if( rc==SQLITE_OK ){
      rc = fts5ExprNodeNextMatch(pExpr, pNode);
    }
  }

  /* Assert that if bFromValid was true, either:
  **
  **   a) an error occurred, or
  **   b) the node is now at EOF, or
  **   c) the node is now at or past rowid iFrom.
  */
  assert( bFromValid==0 
      || rc!=SQLITE_OK                                                  /* a */
      || pNode->bEof                                                    /* b */
      || pNode->iRowid==iFrom || pExpr->bDesc==(pNode->iRowid<iFrom)    /* c */
  );

  return rc;
}


/*
** If pNode currently points to a match, this function returns SQLITE_OK
** without modifying it. Otherwise, pNode is advanced until it does point
** to a match or EOF is reached.
*/
static int fts5ExprNodeNextMatch(
  Fts5Expr *pExpr,                /* Expression of which pNode is a part */
  Fts5ExprNode *pNode             /* Expression node to test */
){
  int rc = SQLITE_OK;
  if( pNode->bEof==0 ){
    switch( pNode->eType ){

      case FTS5_STRING: {
        /* Advance the iterators until they all point to the same rowid */
        rc = fts5ExprNearNextMatch(pExpr, pNode);
        break;
      }

      case FTS5_TERM: {
        rc = fts5ExprTokenTest(pExpr, pNode);
        break;
      }

      case FTS5_AND: {
        rc = fts5ExprAndNextRowid(pExpr, pNode);
        break;
      }

      case FTS5_OR: {
        Fts5ExprNode *pNext = pNode->apChild[0];
        int i;

        for(i=1; i<pNode->nChild; i++){
          Fts5ExprNode *pChild = pNode->apChild[i];
          int cmp = fts5NodeCompare(pExpr, pNext, pChild);
          if( cmp>0 || (cmp==0 && pChild->bNomatch==0) ){
            pNext = pChild;
          }
        }
        pNode->iRowid = pNext->iRowid;
        pNode->bEof = pNext->bEof;
        pNode->bNomatch = pNext->bNomatch;
        break;
      }

      default: assert( pNode->eType==FTS5_NOT ); {
        Fts5ExprNode *p1 = pNode->apChild[0];
        Fts5ExprNode *p2 = pNode->apChild[1];
        assert( pNode->nChild==2 );

        while( rc==SQLITE_OK && p1->bEof==0 ){
          int cmp = fts5NodeCompare(pExpr, p1, p2);
          if( cmp>0 ){
            rc = fts5ExprNodeNext(pExpr, p2, 1, p1->iRowid);
            cmp = fts5NodeCompare(pExpr, p1, p2);
          }
          assert( rc!=SQLITE_OK || cmp<=0 );
          if( cmp || p2->bNomatch ) break;
          rc = fts5ExprNodeNext(pExpr, p1, 0, 0);
        }
        pNode->bEof = p1->bEof;
        pNode->iRowid = p1->iRowid;
        break;
      }
    }
  }
  return rc;
}

................................................................................
**
** Return an SQLite error code if an error occurs, or SQLITE_OK otherwise.
** It is not an error if there are no matches.
*/
static int fts5ExprNodeFirst(Fts5Expr *pExpr, Fts5ExprNode *pNode){
  int rc = SQLITE_OK;
  pNode->bEof = 0;


  if( Fts5NodeIsString(pNode) ){
    /* Initialize all term iterators in the NEAR object. */
    rc = fts5ExprNearInitAll(pExpr, pNode);
  }else{
    int i;

    for(i=0; i<pNode->nChild && rc==SQLITE_OK; i++){

      rc = fts5ExprNodeFirst(pExpr, pNode->apChild[i]);


    }
    pNode->iRowid = pNode->apChild[0]->iRowid;















  }

  if( rc==SQLITE_OK ){
    rc = fts5ExprNodeNextMatch(pExpr, pNode);
  }
  return rc;
}


/*
** Begin iterating through the set of documents in index pIdx matched by
................................................................................
**
** Return SQLITE_OK if successful, or an SQLite error code otherwise. It
** is not considered an error if the query does not match any documents.
*/
static int sqlite3Fts5ExprFirst(Fts5Expr *p, Fts5Index *pIdx, i64 iFirst, int bDesc){
  Fts5ExprNode *pRoot = p->pRoot;
  int rc = SQLITE_OK;
  if( pRoot ){
    p->pIndex = pIdx;
    p->bDesc = bDesc;
    rc = fts5ExprNodeFirst(p, pRoot);

    /* If not at EOF but the current rowid occurs earlier than iFirst in
    ** the iteration order, move to document iFirst or later. */
    if( pRoot->bEof==0 && fts5RowidCmp(p, pRoot->iRowid, iFirst)<0 ){
      rc = fts5ExprNodeNext(p, pRoot, 1, iFirst);
    }

    /* If the iterator is not at a real match, skip forward until it is. */
    while( pRoot->bNomatch && rc==SQLITE_OK && pRoot->bEof==0 ){

      rc = fts5ExprNodeNext(p, pRoot, 0, 0);
    }
  }
  return rc;
}

/*
................................................................................
**
** Return SQLITE_OK if successful, or an SQLite error code otherwise. It
** is not considered an error if the query does not match any documents.
*/
static int sqlite3Fts5ExprNext(Fts5Expr *p, i64 iLast){
  int rc;
  Fts5ExprNode *pRoot = p->pRoot;

  do {
    rc = fts5ExprNodeNext(p, pRoot, 0, 0);

  }while( pRoot->bNomatch && pRoot->bEof==0 && rc==SQLITE_OK );
  if( fts5RowidCmp(p, pRoot->iRowid, iLast)>0 ){
    pRoot->bEof = 1;
  }
  return rc;
}

static int sqlite3Fts5ExprEof(Fts5Expr *p){
  return (p->pRoot==0 || p->pRoot->bEof);
}

static i64 sqlite3Fts5ExprRowid(Fts5Expr *p){
  return p->pRoot->iRowid;
}

static int fts5ParseStringFromToken(Fts5Token *pToken, char **pz){
................................................................................
    int i;
    for(i=0; i<pPhrase->nTerm; i++){
      Fts5ExprTerm *pSyn;
      Fts5ExprTerm *pNext;
      Fts5ExprTerm *pTerm = &pPhrase->aTerm[i];
      sqlite3_free(pTerm->zTerm);
      sqlite3Fts5IterClose(pTerm->pIter);

      for(pSyn=pTerm->pSynonym; pSyn; pSyn=pNext){
        pNext = pSyn->pSynonym;
        sqlite3Fts5IterClose(pSyn->pIter);

        sqlite3_free(pSyn);
      }
    }
    if( pPhrase->poslist.nSpace>0 ) fts5BufferFree(&pPhrase->poslist);
    sqlite3_free(pPhrase);
  }
}
................................................................................
  int iUnused1,                   /* Start offset of token */
  int iUnused2                    /* End offset of token */
){
  int rc = SQLITE_OK;
  const int SZALLOC = 8;
  TokenCtx *pCtx = (TokenCtx*)pContext;
  Fts5ExprPhrase *pPhrase = pCtx->pPhrase;



  /* If an error has already occurred, this is a no-op */
  if( pCtx->rc!=SQLITE_OK ) return pCtx->rc;

  assert( pPhrase==0 || pPhrase->nTerm>0 );
  if( pPhrase && (tflags & FTS5_TOKEN_COLOCATED) ){
    Fts5ExprTerm *pSyn;
    int nByte = sizeof(Fts5ExprTerm) + nToken+1;
    pSyn = (Fts5ExprTerm*)sqlite3_malloc(nByte);
    if( pSyn==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pSyn, 0, nByte);
      pSyn->zTerm = (char*)&pSyn[1];
      memcpy(pSyn->zTerm, pToken, nToken);
      pSyn->pSynonym = pPhrase->aTerm[pPhrase->nTerm-1].pSynonym;
      pPhrase->aTerm[pPhrase->nTerm-1].pSynonym = pSyn;
    }
  }else{
    Fts5ExprTerm *pTerm;
    if( pPhrase==0 || (pPhrase->nTerm % SZALLOC)==0 ){
................................................................................
}

/*
** Create a new FTS5 expression by cloning phrase iPhrase of the
** expression passed as the second argument.
*/
static int sqlite3Fts5ExprClonePhrase(
  Fts5Config *pConfig,
  Fts5Expr *pExpr, 
  int iPhrase, 
  Fts5Expr **ppNew
){
  int rc = SQLITE_OK;             /* Return code */
  Fts5ExprPhrase *pOrig;          /* The phrase extracted from pExpr */
  int i;                          /* Used to iterate through phrase terms */

  Fts5Expr *pNew = 0;             /* Expression to return via *ppNew */

  TokenCtx sCtx = {0,0};          /* Context object for fts5ParseTokenize */


  pOrig = pExpr->apExprPhrase[iPhrase];

  pNew = (Fts5Expr*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Expr));
  if( rc==SQLITE_OK ){
    pNew->apExprPhrase = (Fts5ExprPhrase**)sqlite3Fts5MallocZero(&rc, 
        sizeof(Fts5ExprPhrase*));
  }
  if( rc==SQLITE_OK ){
    pNew->pRoot = (Fts5ExprNode*)sqlite3Fts5MallocZero(&rc, 
................................................................................
      sCtx.pPhrase->aTerm[i].bPrefix = pOrig->aTerm[i].bPrefix;
    }
  }

  if( rc==SQLITE_OK ){
    /* All the allocations succeeded. Put the expression object together. */
    pNew->pIndex = pExpr->pIndex;

    pNew->nPhrase = 1;
    pNew->apExprPhrase[0] = sCtx.pPhrase;
    pNew->pRoot->pNear->apPhrase[0] = sCtx.pPhrase;
    pNew->pRoot->pNear->nPhrase = 1;
    sCtx.pPhrase->pNode = pNew->pRoot;

    if( pOrig->nTerm==1 && pOrig->aTerm[0].pSynonym==0 ){
      pNew->pRoot->eType = FTS5_TERM;

    }else{
      pNew->pRoot->eType = FTS5_STRING;

    }
  }else{
    sqlite3Fts5ExprFree(pNew);
    fts5ExprPhraseFree(sCtx.pPhrase);
    pNew = 0;
  }

................................................................................
}

static void sqlite3Fts5ParseSetColset(
  Fts5Parse *pParse, 
  Fts5ExprNearset *pNear, 
  Fts5Colset *pColset 
){









  if( pNear ){
    pNear->pColset = pColset;
  }else{
    sqlite3_free(pColset);
  }
}

































static void fts5ExprAddChildren(Fts5ExprNode *p, Fts5ExprNode *pSub){
  if( p->eType!=FTS5_NOT && pSub->eType==p->eType ){
    int nByte = sizeof(Fts5ExprNode*) * pSub->nChild;
    memcpy(&p->apChild[p->nChild], pSub->apChild, nByte);
    p->nChild += pSub->nChild;
    sqlite3_free(pSub);
................................................................................

    nByte = sizeof(Fts5ExprNode) + sizeof(Fts5ExprNode*)*(nChild-1);
    pRet = (Fts5ExprNode*)sqlite3Fts5MallocZero(&pParse->rc, nByte);

    if( pRet ){
      pRet->eType = eType;
      pRet->pNear = pNear;

      if( eType==FTS5_STRING ){
        int iPhrase;
        for(iPhrase=0; iPhrase<pNear->nPhrase; iPhrase++){
          pNear->apPhrase[iPhrase]->pNode = pRet;
        }
        if( pNear->nPhrase==1 


         && pNear->apPhrase[0]->nTerm==1 
         && pNear->apPhrase[0]->aTerm[0].pSynonym==0
        ){
          pRet->eType = FTS5_TERM;








        }

      }else{
        fts5ExprAddChildren(pRet, pLeft);
        fts5ExprAddChildren(pRet, pRight);
      }
    }
  }

................................................................................
    for(i=0; i<pNear->nPhrase; i++){
      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];

      zRet = fts5PrintfAppend(zRet, " {");
      for(iTerm=0; zRet && iTerm<pPhrase->nTerm; iTerm++){
        char *zTerm = pPhrase->aTerm[iTerm].zTerm;
        zRet = fts5PrintfAppend(zRet, "%s%s", iTerm==0?"":" ", zTerm);



      }

      if( zRet ) zRet = fts5PrintfAppend(zRet, "}");
      if( zRet==0 ) return 0;
    }

  }else{
................................................................................

  rc = sqlite3Fts5ConfigParse(pGlobal, db, nConfig, azConfig, &pConfig, &zErr);
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts5ExprNew(pConfig, zExpr, &pExpr, &zErr);
  }
  if( rc==SQLITE_OK ){
    char *zText;
    if( pExpr->pRoot==0 ){
      zText = sqlite3_mprintf("");
    }else if( bTcl ){
      zText = fts5ExprPrintTcl(pConfig, zNearsetCmd, pExpr->pRoot);
    }else{
      zText = fts5ExprPrint(pConfig, pExpr->pRoot);
    }
    if( zText==0 ){
................................................................................
    { "fts5_isalnum",  fts5ExprIsAlnum },
    { "fts5_fold",     fts5ExprFold },
  };
  int i;
  int rc = SQLITE_OK;
  void *pCtx = (void*)pGlobal;

  for(i=0; rc==SQLITE_OK && i<(int)ArraySize(aFunc); i++){
    struct Fts5ExprFunc *p = &aFunc[i];
    rc = sqlite3_create_function(db, p->z, -1, SQLITE_UTF8, pCtx, p->x, 0, 0);
  }

  /* Avoid a warning indicating that sqlite3Fts5ParserTrace() is unused */
#ifndef NDEBUG
  (void)sqlite3Fts5ParserTrace;
................................................................................
    nRet = pPhrase->poslist.n;
  }else{
    *pa = 0;
    nRet = 0;
  }
  return nRet;
}




























































































































































































































/*
** 2014 August 11
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
................................................................................
** This file contains the implementation of an in-memory hash table used
** to accumuluate "term -> doclist" content before it is flused to a level-0
** segment.
*/


struct Fts5Hash {

  int *pnByte;                    /* Pointer to bytes counter */
  int nEntry;                     /* Number of entries currently in hash */
  int nSlot;                      /* Size of aSlot[] array */
  Fts5HashEntry *pScan;           /* Current ordered scan item */
  Fts5HashEntry **aSlot;          /* Array of hash slots */
};

................................................................................
struct Fts5HashEntry {
  Fts5HashEntry *pHashNext;       /* Next hash entry with same hash-key */
  Fts5HashEntry *pScanNext;       /* Next entry in sorted order */
  
  int nAlloc;                     /* Total size of allocation */
  int iSzPoslist;                 /* Offset of space for 4-byte poslist size */
  int nData;                      /* Total bytes of data (incl. structure) */

  u8 bDel;                        /* Set delete-flag @ iSzPoslist */


  int iCol;                       /* Column of last value written */
  int iPos;                       /* Position of last value written */
  i64 iRowid;                     /* Rowid of last value written */
  char zKey[8];                   /* Nul-terminated entry key */
};

/*
** Size of Fts5HashEntry without the zKey[] array.
................................................................................
#define FTS5_HASHENTRYSIZE (sizeof(Fts5HashEntry)-8)



/*
** Allocate a new hash table.
*/
static int sqlite3Fts5HashNew(Fts5Hash **ppNew, int *pnByte){
  int rc = SQLITE_OK;
  Fts5Hash *pNew;

  *ppNew = pNew = (Fts5Hash*)sqlite3_malloc(sizeof(Fts5Hash));
  if( pNew==0 ){
    rc = SQLITE_NOMEM;
  }else{
    int nByte;
    memset(pNew, 0, sizeof(Fts5Hash));
    pNew->pnByte = pnByte;


    pNew->nSlot = 1024;
    nByte = sizeof(Fts5HashEntry*) * pNew->nSlot;
    pNew->aSlot = (Fts5HashEntry**)sqlite3_malloc(nByte);
    if( pNew->aSlot==0 ){
      sqlite3_free(pNew);
      *ppNew = 0;
................................................................................

  sqlite3_free(apOld);
  pHash->nSlot = nNew;
  pHash->aSlot = apNew;
  return SQLITE_OK;
}

static void fts5HashAddPoslistSize(Fts5HashEntry *p){
  if( p->iSzPoslist ){
    u8 *pPtr = (u8*)p;









    int nSz = (p->nData - p->iSzPoslist - 1);         /* Size in bytes */
    int nPos = nSz*2 + p->bDel;                       /* Value of nPos field */

    assert( p->bDel==0 || p->bDel==1 );
    if( nPos<=127 ){
      pPtr[p->iSzPoslist] = (u8)nPos;
    }else{
      int nByte = sqlite3Fts5GetVarintLen((u32)nPos);
      memmove(&pPtr[p->iSzPoslist + nByte], &pPtr[p->iSzPoslist + 1], nSz);
      sqlite3Fts5PutVarint(&pPtr[p->iSzPoslist], nPos);
      p->nData += (nByte-1);
    }
    p->bDel = 0;


    p->iSzPoslist = 0;


  }
}









static int sqlite3Fts5HashWrite(
  Fts5Hash *pHash,
  i64 iRowid,                     /* Rowid for this entry */
  int iCol,                       /* Column token appears in (-ve -> delete) */
  int iPos,                       /* Position of token within column */
  char bByte,                     /* First byte of token */
  const char *pToken, int nToken  /* Token to add or remove to or from index */
){
  unsigned int iHash;
  Fts5HashEntry *p;
  u8 *pPtr;
  int nIncr = 0;                  /* Amount to increment (*pHash->pnByte) by */




  /* Attempt to locate an existing hash entry */
  iHash = fts5HashKey2(pHash->nSlot, (u8)bByte, (const u8*)pToken, nToken);
  for(p=pHash->aSlot[iHash]; p; p=p->pHashNext){
    if( p->zKey[0]==bByte 

     && memcmp(&p->zKey[1], pToken, nToken)==0 
     && p->zKey[nToken+1]==0 
    ){
      break;
    }
  }

  /* If an existing hash entry cannot be found, create a new one. */
  if( p==0 ){

    int nByte = FTS5_HASHENTRYSIZE + (nToken+1) + 1 + 64;
    if( nByte<128 ) nByte = 128;


    if( (pHash->nEntry*2)>=pHash->nSlot ){
      int rc = fts5HashResize(pHash);
      if( rc!=SQLITE_OK ) return rc;
      iHash = fts5HashKey2(pHash->nSlot, (u8)bByte, (const u8*)pToken, nToken);
    }


    p = (Fts5HashEntry*)sqlite3_malloc(nByte);
    if( !p ) return SQLITE_NOMEM;
    memset(p, 0, FTS5_HASHENTRYSIZE);
    p->nAlloc = nByte;
    p->zKey[0] = bByte;
    memcpy(&p->zKey[1], pToken, nToken);
    assert( iHash==fts5HashKey(pHash->nSlot, (u8*)p->zKey, nToken+1) );

    p->zKey[nToken+1] = '\0';
    p->nData = nToken+1 + 1 + FTS5_HASHENTRYSIZE;
    p->nData += sqlite3Fts5PutVarint(&((u8*)p)[p->nData], iRowid);
    p->iSzPoslist = p->nData;
    p->nData += 1;
    p->iRowid = iRowid;
    p->pHashNext = pHash->aSlot[iHash];
    pHash->aSlot[iHash] = p;
    pHash->nEntry++;





    nIncr += p->nData;



  }





  /* Check there is enough space to append a new entry. Worst case scenario
  ** is:
  **
  **     + 9 bytes for a new rowid,
  **     + 4 byte reserved for the "poslist size" varint.
  **     + 1 byte for a "new column" byte,
  **     + 3 bytes for a new column number (16-bit max) as a varint,
  **     + 5 bytes for the new position offset (32-bit max).
  */
  if( (p->nAlloc - p->nData) < (9 + 4 + 1 + 3 + 5) ){
    int nNew = p->nAlloc * 2;
    Fts5HashEntry *pNew;
    Fts5HashEntry **pp;
    pNew = (Fts5HashEntry*)sqlite3_realloc(p, nNew);
    if( pNew==0 ) return SQLITE_NOMEM;
    pNew->nAlloc = nNew;
    for(pp=&pHash->aSlot[iHash]; *pp!=p; pp=&(*pp)->pHashNext);
    *pp = pNew;
    p = pNew;
  }
  pPtr = (u8*)p;
  nIncr -= p->nData;





  /* If this is a new rowid, append the 4-byte size field for the previous
  ** entry, and the new rowid for this entry.  */
  if( iRowid!=p->iRowid ){
    fts5HashAddPoslistSize(p);
    p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iRowid - p->iRowid);


    p->iSzPoslist = p->nData;

    p->nData += 1;
    p->iCol = 0;

    p->iPos = 0;
    p->iRowid = iRowid;
  }


  if( iCol>=0 ){



    /* Append a new column value, if necessary */
    assert( iCol>=p->iCol );
    if( iCol!=p->iCol ){

      pPtr[p->nData++] = 0x01;
      p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iCol);
      p->iCol = iCol;
      p->iPos = 0;



    }


    /* Append the new position offset */

    p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iPos - p->iPos + 2);
    p->iPos = iPos;


  }else{
    /* This is a delete. Set the delete flag. */
    p->bDel = 1;
  }
  nIncr += p->nData;


  *pHash->pnByte += nIncr;
  return SQLITE_OK;
}


/*
** Arguments pLeft and pRight point to linked-lists of hash-entry objects,
................................................................................
  Fts5HashEntry *p;

  for(p=pHash->aSlot[iHash]; p; p=p->pHashNext){
    if( memcmp(p->zKey, pTerm, nTerm)==0 && p->zKey[nTerm]==0 ) break;
  }

  if( p ){
    fts5HashAddPoslistSize(p);
    *ppDoclist = (const u8*)&p->zKey[nTerm+1];
    *pnDoclist = p->nData - (FTS5_HASHENTRYSIZE + nTerm + 1);
  }else{
    *ppDoclist = 0;
    *pnDoclist = 0;
  }

................................................................................
  const char **pzTerm,            /* OUT: term (nul-terminated) */
  const u8 **ppDoclist,           /* OUT: pointer to doclist */
  int *pnDoclist                  /* OUT: size of doclist in bytes */
){
  Fts5HashEntry *p;
  if( (p = pHash->pScan) ){
    int nTerm = (int)strlen(p->zKey);
    fts5HashAddPoslistSize(p);
    *pzTerm = p->zKey;
    *ppDoclist = (const u8*)&p->zKey[nTerm+1];
    *pnDoclist = p->nData - (FTS5_HASHENTRYSIZE + nTerm + 1);
  }else{
    *pzTerm = 0;
    *ppDoclist = 0;
    *pnDoclist = 0;
................................................................................
#define FTS5_DATA_ZERO_PADDING 8
#define FTS5_DATA_PADDING 20

typedef struct Fts5Data Fts5Data;
typedef struct Fts5DlidxIter Fts5DlidxIter;
typedef struct Fts5DlidxLvl Fts5DlidxLvl;
typedef struct Fts5DlidxWriter Fts5DlidxWriter;

typedef struct Fts5PageWriter Fts5PageWriter;
typedef struct Fts5SegIter Fts5SegIter;
typedef struct Fts5DoclistIter Fts5DoclistIter;
typedef struct Fts5SegWriter Fts5SegWriter;
typedef struct Fts5Structure Fts5Structure;
typedef struct Fts5StructureLevel Fts5StructureLevel;
typedef struct Fts5StructureSegment Fts5StructureSegment;
................................................................................
  Fts5StructureSegment *pSeg;     /* Segment to iterate through */
  int flags;                      /* Mask of configuration flags */
  int iLeafPgno;                  /* Current leaf page number */
  Fts5Data *pLeaf;                /* Current leaf data */
  Fts5Data *pNextLeaf;            /* Leaf page (iLeafPgno+1) */
  int iLeafOffset;                /* Byte offset within current leaf */




  /* The page and offset from which the current term was read. The offset 
  ** is the offset of the first rowid in the current doclist.  */
  int iTermLeafPgno;
  int iTermLeafOffset;

  int iPgidxOff;                  /* Next offset in pgidx */
  int iEndofDoclist;
................................................................................

  Fts5DlidxIter *pDlidx;          /* If there is a doclist-index */

  /* Variables populated based on current entry. */
  Fts5Buffer term;                /* Current term */
  i64 iRowid;                     /* Current rowid */
  int nPos;                       /* Number of bytes in current position list */
  int bDel;                       /* True if the delete flag is set */
};

/*
** Argument is a pointer to an Fts5Data structure that contains a 
** leaf page.
*/
#define ASSERT_SZLEAF_OK(x) assert( \
    (x)->szLeaf==(x)->nn || (x)->szLeaf==fts5GetU16(&(x)->p[2]) \
)

#define FTS5_SEGITER_ONETERM 0x01
#define FTS5_SEGITER_REVERSE 0x02


/* 
** Argument is a pointer to an Fts5Data structure that contains a leaf
** page. This macro evaluates to true if the leaf contains no terms, or
** false if it contains at least one term.
*/
#define fts5LeafIsTermless(x) ((x)->szLeaf >= (x)->nn)
................................................................................
** aFirst[1] contains the index in aSeg[] of the iterator that points to
** the smallest key overall. aFirst[0] is unused. 
**
** poslist:
**   Used by sqlite3Fts5IterPoslist() when the poslist needs to be buffered.
**   There is no way to tell if this is populated or not.
*/
struct Fts5IndexIter {


  Fts5Index *pIndex;              /* Index that owns this iterator */
  Fts5Structure *pStruct;         /* Database structure for this iterator */
  Fts5Buffer poslist;             /* Buffer containing current poslist */





  int nSeg;                       /* Size of aSeg[] array */
  int bRev;                       /* True to iterate in reverse order */
  u8 bSkipEmpty;                  /* True to skip deleted entries */
  u8 bEof;                        /* True at EOF */
  u8 bFiltered;                   /* True if column-filter already applied */

  i64 iSwitchRowid;               /* Firstest rowid of other than aFirst[1] */
  Fts5CResult *aFirst;            /* Current merge state (see above) */
  Fts5SegIter aSeg[1];            /* Array of segment iterators */
};


................................................................................
*/
static int fts5BufferCompare(Fts5Buffer *pLeft, Fts5Buffer *pRight){
  int nCmp = MIN(pLeft->n, pRight->n);
  int res = memcmp(pLeft->p, pRight->p, nCmp);
  return (res==0 ? (pLeft->n - pRight->n) : res);
}

#ifdef SQLITE_DEBUG
static int fts5BlobCompare(
  const u8 *pLeft, int nLeft, 
  const u8 *pRight, int nRight
){
  int nCmp = MIN(nLeft, nRight);
  int res = memcmp(pLeft, pRight, nCmp);
  return (res==0 ? (nLeft - nRight) : res);
}
#endif

static int fts5LeafFirstTermOff(Fts5Data *pLeaf){
  int ret;
  fts5GetVarint32(&pLeaf->p[pLeaf->szLeaf], ret);
  return ret;
}

/*
................................................................................
    i += sqlite3Fts5GetVarint(&pData[i], &pRet->nWriteCounter);

    for(iLvl=0; rc==SQLITE_OK && iLvl<nLevel; iLvl++){
      Fts5StructureLevel *pLvl = &pRet->aLevel[iLvl];
      int nTotal;
      int iSeg;




      i += fts5GetVarint32(&pData[i], pLvl->nMerge);
      i += fts5GetVarint32(&pData[i], nTotal);
      assert( nTotal>=pLvl->nMerge );
      pLvl->aSeg = (Fts5StructureSegment*)sqlite3Fts5MallocZero(&rc, 
          nTotal * sizeof(Fts5StructureSegment)
      );


      if( rc==SQLITE_OK ){
        pLvl->nSeg = nTotal;
        for(iSeg=0; iSeg<nTotal; iSeg++){




          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].iSegid);
          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].pgnoFirst);
          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].pgnoLast);
        }
      }else{



        fts5StructureRelease(pRet);
        pRet = 0;
      }
    }
  }

  *ppOut = pRet;
  return rc;
}

................................................................................
**
** Leave Fts5SegIter.iLeafOffset pointing to the first byte of the 
** position list content (if any).
*/
static void fts5SegIterLoadNPos(Fts5Index *p, Fts5SegIter *pIter){
  if( p->rc==SQLITE_OK ){
    int iOff = pIter->iLeafOffset;  /* Offset to read at */
    int nSz;
    ASSERT_SZLEAF_OK(pIter->pLeaf);
















    fts5FastGetVarint32(pIter->pLeaf->p, iOff, nSz);
    pIter->bDel = (nSz & 0x0001);
    pIter->nPos = nSz>>1;
    pIter->iLeafOffset = iOff;
    assert_nc( pIter->nPos>=0 );


  }
}

static void fts5SegIterLoadRowid(Fts5Index *p, Fts5SegIter *pIter){
  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */
  int iOff = pIter->iLeafOffset;

................................................................................
*/
static void fts5SegIterLoadTerm(Fts5Index *p, Fts5SegIter *pIter, int nKeep){
  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */
  int iOff = pIter->iLeafOffset;  /* Offset to read at */
  int nNew;                       /* Bytes of new data */

  iOff += fts5GetVarint32(&a[iOff], nNew);




  pIter->term.n = nKeep;
  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);
  iOff += nNew;
  pIter->iTermLeafOffset = iOff;
  pIter->iTermLeafPgno = pIter->iLeafPgno;
  pIter->iLeafOffset = iOff;

................................................................................
    int nExtra;
    pIter->iPgidxOff += fts5GetVarint32(&a[pIter->iPgidxOff], nExtra);
    pIter->iEndofDoclist += nExtra;
  }

  fts5SegIterLoadRowid(p, pIter);
}















/*
** Initialize the iterator object pIter to iterate through the entries in
** segment pSeg. The iterator is left pointing to the first entry when 
** this function returns.
**
** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 
................................................................................
    ** at EOF already. */
    assert( pIter->pLeaf==0 );
    return;
  }

  if( p->rc==SQLITE_OK ){
    memset(pIter, 0, sizeof(*pIter));

    pIter->pSeg = pSeg;
    pIter->iLeafPgno = pSeg->pgnoFirst-1;
    fts5SegIterNextPage(p, pIter);
  }

  if( p->rc==SQLITE_OK ){
    pIter->iLeafOffset = 4;
................................................................................
** This function advances the iterator so that it points to the last 
** relevant rowid on the page and, if necessary, initializes the 
** aRowidOffset[] and iRowidOffset variables. At this point the iterator
** is in its regular state - Fts5SegIter.iLeafOffset points to the first
** byte of the position list content associated with said rowid.
*/
static void fts5SegIterReverseInitPage(Fts5Index *p, Fts5SegIter *pIter){

  int n = pIter->pLeaf->szLeaf;
  int i = pIter->iLeafOffset;
  u8 *a = pIter->pLeaf->p;
  int iRowidOffset = 0;

  if( n>pIter->iEndofDoclist ){
    n = pIter->iEndofDoclist;
  }

  ASSERT_SZLEAF_OK(pIter->pLeaf);
  while( 1 ){
    i64 iDelta = 0;








    int nPos;
    int bDummy;

    i += fts5GetPoslistSize(&a[i], &nPos, &bDummy);
    i += nPos;

    if( i>=n ) break;
    i += fts5GetVarint(&a[i], (u64*)&iDelta);
    pIter->iRowid += iDelta;


    if( iRowidOffset>=pIter->nRowidOffset ){
      int nNew = pIter->nRowidOffset + 8;
      int *aNew = (int*)sqlite3_realloc(pIter->aRowidOffset, nNew*sizeof(int));
      if( aNew==0 ){
        p->rc = SQLITE_NOMEM;
        break;
      }
................................................................................
}

/*
** Return true if the iterator passed as the second argument currently
** points to a delete marker. A delete marker is an entry with a 0 byte
** position-list.
*/
static int fts5MultiIterIsEmpty(Fts5Index *p, Fts5IndexIter *pIter){
  Fts5SegIter *pSeg = &pIter->aSeg[pIter->aFirst[1].iFirst];
  return (p->rc==SQLITE_OK && pSeg->pLeaf && pSeg->nPos==0);
}

/*
** Advance iterator pIter to the next entry. 
**
** If an error occurs, Fts5Index.rc is set to an appropriate error code. It 
** is not considered an error if the iterator reaches EOF. If an error has 
** already occurred when this function is called, it is a no-op.
*/
static void fts5SegIterNext(
  Fts5Index *p,                   /* FTS5 backend object */
  Fts5SegIter *pIter,             /* Iterator to advance */
  int *pbNewTerm                  /* OUT: Set for new term */

){
  assert( pbNewTerm==0 || *pbNewTerm==0 );
  if( p->rc==SQLITE_OK ){
    if( pIter->flags & FTS5_SEGITER_REVERSE ){
      assert( pIter->pNextLeaf==0 );


      if( pIter->iRowidOffset>0 ){
        u8 *a = pIter->pLeaf->p;
        int iOff;
        int nPos;
        int bDummy;
        i64 iDelta;

        pIter->iRowidOffset--;
        pIter->iLeafOffset = iOff = pIter->aRowidOffset[pIter->iRowidOffset];
        iOff += fts5GetPoslistSize(&a[iOff], &nPos, &bDummy);



        iOff += nPos;

        fts5GetVarint(&a[iOff], (u64*)&iDelta);
        pIter->iRowid -= iDelta;
        fts5SegIterLoadNPos(p, pIter);
      }else{
        fts5SegIterReverseNewPage(p, pIter);
      }












































    }else{








































      Fts5Data *pLeaf = pIter->pLeaf;
      int iOff;
      int bNewTerm = 0;
      int nKeep = 0;






      /* Search for the end of the position list within the current page. */
      u8 *a = pLeaf->p;
      int n = pLeaf->szLeaf;

      ASSERT_SZLEAF_OK(pLeaf);
      iOff = pIter->iLeafOffset + pIter->nPos;

      if( iOff<n ){
        /* The next entry is on the current page. */
        assert_nc( iOff<=pIter->iEndofDoclist );
        if( iOff>=pIter->iEndofDoclist ){
          bNewTerm = 1;
          if( iOff!=fts5LeafFirstTermOff(pLeaf) ){
            iOff += fts5GetVarint32(&a[iOff], nKeep);
          }
        }else{
          u64 iDelta;
          iOff += sqlite3Fts5GetVarint(&a[iOff], &iDelta);
          pIter->iRowid += iDelta;
          assert_nc( iDelta>0 );
        }
        pIter->iLeafOffset = iOff;

      }else if( pIter->pSeg==0 ){
        const u8 *pList = 0;
        const char *zTerm = 0;
        int nList = 0;
        assert( (pIter->flags & FTS5_SEGITER_ONETERM) || pbNewTerm );
        if( 0==(pIter->flags & FTS5_SEGITER_ONETERM) ){
          sqlite3Fts5HashScanNext(p->pHash);
          sqlite3Fts5HashScanEntry(p->pHash, &zTerm, &pList, &nList);
        }
        if( pList==0 ){
          fts5DataRelease(pIter->pLeaf);
          pIter->pLeaf = 0;
        }else{
          pIter->pLeaf->p = (u8*)pList;
          pIter->pLeaf->nn = nList;
          pIter->pLeaf->szLeaf = nList;
          pIter->iEndofDoclist = nList+1;
          sqlite3Fts5BufferSet(&p->rc, &pIter->term, (int)strlen(zTerm),
              (u8*)zTerm);
          pIter->iLeafOffset = fts5GetVarint(pList, (u64*)&pIter->iRowid);
          *pbNewTerm = 1;
        }
      }else{
        iOff = 0;
        /* Next entry is not on the current page */
        while( iOff==0 ){
          fts5SegIterNextPage(p, pIter);
          pLeaf = pIter->pLeaf;
          if( pLeaf==0 ) break;
          ASSERT_SZLEAF_OK(pLeaf);
          if( (iOff = fts5LeafFirstRowidOff(pLeaf)) && iOff<pLeaf->szLeaf ){
            iOff += sqlite3Fts5GetVarint(&pLeaf->p[iOff], (u64*)&pIter->iRowid);
            pIter->iLeafOffset = iOff;

            if( pLeaf->nn>pLeaf->szLeaf ){
              pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(
                  &pLeaf->p[pLeaf->szLeaf], pIter->iEndofDoclist
              );
            }

          }
          else if( pLeaf->nn>pLeaf->szLeaf ){
            pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(
                &pLeaf->p[pLeaf->szLeaf], iOff
            );
            pIter->iLeafOffset = iOff;
            pIter->iEndofDoclist = iOff;
            bNewTerm = 1;
          }

          if( iOff>=pLeaf->szLeaf ){
            p->rc = FTS5_CORRUPT;
            return;
          }
        }
      }

      /* Check if the iterator is now at EOF. If so, return early. */
      if( pIter->pLeaf ){
        if( bNewTerm ){
          if( pIter->flags & FTS5_SEGITER_ONETERM ){
            fts5DataRelease(pIter->pLeaf);
            pIter->pLeaf = 0;
          }else{
            fts5SegIterLoadTerm(p, pIter, nKeep);
            fts5SegIterLoadNPos(p, pIter);
            if( pbNewTerm ) *pbNewTerm = 1;
          }
        }else{
          /* The following could be done by calling fts5SegIterLoadNPos(). But
          ** this block is particularly performance critical, so equivalent
          ** code is inlined. */




          int nSz;
          assert( p->rc==SQLITE_OK );
          fts5FastGetVarint32(pIter->pLeaf->p, pIter->iLeafOffset, nSz);
          pIter->bDel = (nSz & 0x0001);
          pIter->nPos = nSz>>1;
          assert_nc( pIter->nPos>=0 );
        }
      }
    }
  }

}




#define SWAPVAL(T, a, b) { T tmp; tmp=a; a=b; b=tmp; }

/*
** Iterator pIter currently points to the first rowid in a doclist. This
** function sets the iterator up so that iterates in reverse order through
** the doclist.
*/
static void fts5SegIterReverse(Fts5Index *p, Fts5SegIter *pIter){
................................................................................
    pLast = fts5DataRead(p, FTS5_SEGMENT_ROWID(iSegid, pgnoLast));
  }else{
    Fts5Data *pLeaf = pIter->pLeaf;         /* Current leaf data */

    /* Currently, Fts5SegIter.iLeafOffset points to the first byte of
    ** position-list content for the current rowid. Back it up so that it
    ** points to the start of the position-list size field. */







    pIter->iLeafOffset -= sqlite3Fts5GetVarintLen(pIter->nPos*2+pIter->bDel);

    /* If this condition is true then the largest rowid for the current
    ** term may not be stored on the current page. So search forward to
    ** see where said rowid really is.  */
    if( pIter->iEndofDoclist>=pLeaf->szLeaf ){
      int pgno;
      Fts5StructureSegment *pSeg = pIter->pSeg;
................................................................................
  ){
    return;
  }

  pIter->pDlidx = fts5DlidxIterInit(p, bRev, iSeg, pIter->iTermLeafPgno);
}

#define fts5IndexSkipVarint(a, iOff) {            \
  int iEnd = iOff+9;                              \
  while( (a[iOff++] & 0x80) && iOff<iEnd );       \
}

/*
** The iterator object passed as the second argument currently contains
** no valid values except for the Fts5SegIter.pLeaf member variable. This
** function searches the leaf page for a term matching (pTerm/nTerm).
**
** If the specified term is found on the page, then the iterator is left
** pointing to it. If argument bGe is zero and the term is not found,
................................................................................
** pSeg. If there is no such term in the index, the iterator is set to EOF.
**
** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 
** an error has already occurred when this function is called, it is a no-op.
*/
static void fts5SegIterSeekInit(
  Fts5Index *p,                   /* FTS5 backend */
  Fts5Buffer *pBuf,               /* Buffer to use for loading pages */
  const u8 *pTerm, int nTerm,     /* Term to seek to */
  int flags,                      /* Mask of FTS5INDEX_XXX flags */
  Fts5StructureSegment *pSeg,     /* Description of segment */
  Fts5SegIter *pIter              /* Object to populate */
){
  int iPg = 1;
  int bGe = (flags & FTS5INDEX_QUERY_SCAN);
  int bDlidx = 0;                 /* True if there is a doclist-index */

  static int nCall = 0;
  nCall++;

  assert( bGe==0 || (flags & FTS5INDEX_QUERY_DESC)==0 );
  assert( pTerm && nTerm );
  memset(pIter, 0, sizeof(*pIter));
  pIter->pSeg = pSeg;

  /* This block sets stack variable iPg to the leaf page number that may
  ** contain term (pTerm/nTerm), if it is present in the segment. */
................................................................................
        fts5SegIterLoadDlidx(p, pIter);
      }
      if( flags & FTS5INDEX_QUERY_DESC ){
        fts5SegIterReverse(p, pIter);
      }
    }
  }



  /* Either:
  **
  **   1) an error has occurred, or
  **   2) the iterator points to EOF, or
  **   3) the iterator points to an entry with term (pTerm/nTerm), or
  **   4) the FTS5INDEX_QUERY_SCAN flag was set and the iterator points
................................................................................
    sqlite3Fts5BufferSet(&p->rc, &pIter->term, n, z);
    pLeaf = fts5IdxMalloc(p, sizeof(Fts5Data));
    if( pLeaf==0 ) return;
    pLeaf->p = (u8*)pList;
    pLeaf->nn = pLeaf->szLeaf = nList;
    pIter->pLeaf = pLeaf;
    pIter->iLeafOffset = fts5GetVarint(pLeaf->p, (u64*)&pIter->iRowid);
    pIter->iEndofDoclist = pLeaf->nn+1;

    if( flags & FTS5INDEX_QUERY_DESC ){
      pIter->flags |= FTS5_SEGITER_REVERSE;
      fts5SegIterReverseInitPage(p, pIter);
    }else{
      fts5SegIterLoadNPos(p, pIter);
    }
  }


}

/*
** Zero the iterator passed as the only argument.
*/
static void fts5SegIterClear(Fts5SegIter *pIter){
  fts5BufferFree(&pIter->term);
................................................................................
/*
** This function is used as part of the big assert() procedure implemented by
** fts5AssertMultiIterSetup(). It ensures that the result currently stored
** in *pRes is the correct result of comparing the current positions of the
** two iterators.
*/
static void fts5AssertComparisonResult(
  Fts5IndexIter *pIter, 
  Fts5SegIter *p1,
  Fts5SegIter *p2,
  Fts5CResult *pRes
){
  int i1 = p1 - pIter->aSeg;
  int i2 = p2 - pIter->aSeg;

................................................................................

/*
** This function is a no-op unless SQLITE_DEBUG is defined when this module
** is compiled. In that case, this function is essentially an assert() 
** statement used to verify that the contents of the pIter->aFirst[] array
** are correct.
*/
static void fts5AssertMultiIterSetup(Fts5Index *p, Fts5IndexIter *pIter){
  if( p->rc==SQLITE_OK ){
    Fts5SegIter *pFirst = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
    int i;

    assert( (pFirst->pLeaf==0)==pIter->bEof );

    /* Check that pIter->iSwitchRowid is set correctly. */
    for(i=0; i<pIter->nSeg; i++){
      Fts5SegIter *p1 = &pIter->aSeg[i];
      assert( p1==pFirst 
           || p1->pLeaf==0 
           || fts5BufferCompare(&pFirst->term, &p1->term) 
................................................................................
** Do the comparison necessary to populate pIter->aFirst[iOut].
**
** If the returned value is non-zero, then it is the index of an entry
** in the pIter->aSeg[] array that is (a) not at EOF, and (b) pointing
** to a key that is a duplicate of another, higher priority, 
** segment-iterator in the pSeg->aSeg[] array.
*/
static int fts5MultiIterDoCompare(Fts5IndexIter *pIter, int iOut){
  int i1;                         /* Index of left-hand Fts5SegIter */
  int i2;                         /* Index of right-hand Fts5SegIter */
  int iRes;
  Fts5SegIter *p1;                /* Left-hand Fts5SegIter */
  Fts5SegIter *p2;                /* Right-hand Fts5SegIter */
  Fts5CResult *pRes = &pIter->aFirst[iOut];

................................................................................
      pIter->iLeafPgno = iLeafPgno+1;
      fts5SegIterReverseNewPage(p, pIter);
      bMove = 0;
    }
  }

  do{
    if( bMove ) fts5SegIterNext(p, pIter, 0);
    if( pIter->pLeaf==0 ) break;
    if( bRev==0 && pIter->iRowid>=iMatch ) break;
    if( bRev!=0 && pIter->iRowid<=iMatch ) break;
    bMove = 1;
  }while( p->rc==SQLITE_OK );
}


/*
** Free the iterator object passed as the second argument.
*/
static void fts5MultiIterFree(Fts5Index *p, Fts5IndexIter *pIter){
  if( pIter ){
    int i;
    for(i=0; i<pIter->nSeg; i++){
      fts5SegIterClear(&pIter->aSeg[i]);
    }
    fts5StructureRelease(pIter->pStruct);
    fts5BufferFree(&pIter->poslist);
    sqlite3_free(pIter);
  }
}

static void fts5MultiIterAdvanced(
  Fts5Index *p,                   /* FTS5 backend to iterate within */
  Fts5IndexIter *pIter,           /* Iterator to update aFirst[] array for */
  int iChanged,                   /* Index of sub-iterator just advanced */
  int iMinset                     /* Minimum entry in aFirst[] to set */
){
  int i;
  for(i=(pIter->nSeg+iChanged)/2; i>=iMinset && p->rc==SQLITE_OK; i=i/2){
    int iEq;
    if( (iEq = fts5MultiIterDoCompare(pIter, i)) ){
      fts5SegIterNext(p, &pIter->aSeg[iEq], 0);


      i = pIter->nSeg + iEq;
    }
  }
}

/*
** Sub-iterator iChanged of iterator pIter has just been advanced. It still
................................................................................
** If it does so successfully, 0 is returned. Otherwise 1.
**
** If non-zero is returned, the caller should call fts5MultiIterAdvanced()
** on the iterator instead. That function does the same as this one, except
** that it deals with more complicated cases as well.
*/ 
static int fts5MultiIterAdvanceRowid(
  Fts5Index *p,                   /* FTS5 backend to iterate within */
  Fts5IndexIter *pIter,           /* Iterator to update aFirst[] array for */
  int iChanged                    /* Index of sub-iterator just advanced */
){
  Fts5SegIter *pNew = &pIter->aSeg[iChanged];

  if( pNew->iRowid==pIter->iSwitchRowid
   || (pNew->iRowid<pIter->iSwitchRowid)==pIter->bRev
  ){
    int i;
................................................................................
      pRes->iFirst = (u16)(pNew - pIter->aSeg);
      if( i==1 ) break;

      pOther = &pIter->aSeg[ pIter->aFirst[i ^ 0x0001].iFirst ];
    }
  }


  return 0;
}

/*
** Set the pIter->bEof variable based on the state of the sub-iterators.
*/
static void fts5MultiIterSetEof(Fts5IndexIter *pIter){
  Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
  pIter->bEof = pSeg->pLeaf==0;
  pIter->iSwitchRowid = pSeg->iRowid;
}

/*
** Move the iterator to the next entry. 
**
** If an error occurs, an error code is left in Fts5Index.rc. It is not 
** considered an error if the iterator reaches EOF, or if it is already at 
** EOF when this function is called.
*/
static void fts5MultiIterNext(
  Fts5Index *p, 
  Fts5IndexIter *pIter,
  int bFrom,                      /* True if argument iFrom is valid */
  i64 iFrom                       /* Advance at least as far as this */
){
  if( p->rc==SQLITE_OK ){
    int bUseFrom = bFrom;
    do {

      int iFirst = pIter->aFirst[1].iFirst;
      int bNewTerm = 0;
      Fts5SegIter *pSeg = &pIter->aSeg[iFirst];
      assert( p->rc==SQLITE_OK );
      if( bUseFrom && pSeg->pDlidx ){
        fts5SegIterNextFrom(p, pSeg, iFrom);
      }else{
        fts5SegIterNext(p, pSeg, &bNewTerm);
      }

      if( pSeg->pLeaf==0 || bNewTerm 
       || fts5MultiIterAdvanceRowid(p, pIter, iFirst)
      ){
        fts5MultiIterAdvanced(p, pIter, iFirst, 1);
        fts5MultiIterSetEof(pIter);


      }

      fts5AssertMultiIterSetup(p, pIter);





      bUseFrom = 0;
    }while( pIter->bSkipEmpty && fts5MultiIterIsEmpty(p, pIter) );
  }
}

static void fts5MultiIterNext2(
  Fts5Index *p, 
  Fts5IndexIter *pIter,
  int *pbNewTerm                  /* OUT: True if *might* be new term */
){
  assert( pIter->bSkipEmpty );
  if( p->rc==SQLITE_OK ){
    do {
      int iFirst = pIter->aFirst[1].iFirst;
      Fts5SegIter *pSeg = &pIter->aSeg[iFirst];
      int bNewTerm = 0;


      fts5SegIterNext(p, pSeg, &bNewTerm);
      if( pSeg->pLeaf==0 || bNewTerm 
       || fts5MultiIterAdvanceRowid(p, pIter, iFirst)
      ){
        fts5MultiIterAdvanced(p, pIter, iFirst, 1);
        fts5MultiIterSetEof(pIter);
        *pbNewTerm = 1;
      }else{
        *pbNewTerm = 0;
      }
      fts5AssertMultiIterSetup(p, pIter);

    }while( fts5MultiIterIsEmpty(p, pIter) );
  }
}





static Fts5IndexIter *fts5MultiIterAlloc(
  Fts5Index *p,                   /* FTS5 backend to iterate within */
  int nSeg
){
  Fts5IndexIter *pNew;
  int nSlot;                      /* Power of two >= nSeg */

  for(nSlot=2; nSlot<nSeg; nSlot=nSlot*2);
  pNew = fts5IdxMalloc(p, 
      sizeof(Fts5IndexIter) +             /* pNew */
      sizeof(Fts5SegIter) * (nSlot-1) +   /* pNew->aSeg[] */
      sizeof(Fts5CResult) * nSlot         /* pNew->aFirst[] */
  );
  if( pNew ){
    pNew->nSeg = nSlot;
    pNew->aFirst = (Fts5CResult*)&pNew->aSeg[nSlot];
    pNew->pIndex = p;

  }
  return pNew;
}

/*
** Allocate a new Fts5IndexIter object.
**
** The new object will be used to iterate through data in structure pStruct.
** If iLevel is -ve, then all data in all segments is merged. Or, if iLevel
** is zero or greater, data from the first nSegment segments on level iLevel
** is merged.
**
** The iterator initially points to the first term/rowid entry in the 
** iterated data.
*/
static void fts5MultiIterNew(
  Fts5Index *p,                   /* FTS5 backend to iterate within */
  Fts5Structure *pStruct,         /* Structure of specific index */
  int bSkipEmpty,                 /* True to ignore delete-keys */
  int flags,                      /* FTS5INDEX_QUERY_XXX flags */
  const u8 *pTerm, int nTerm,     /* Term to seek to (or NULL/0) */
  int iLevel,                     /* Level to iterate (-1 for all) */
  int nSegment,                   /* Number of segments to merge (iLevel>=0) */
  Fts5IndexIter **ppOut           /* New object */



){
  int nSeg = 0;                   /* Number of segment-iters in use */
  int iIter = 0;                  /* */
  int iSeg;                       /* Used to iterate through segments */
  Fts5Buffer buf = {0,0,0};       /* Buffer used by fts5SegIterSeekInit() */
  Fts5StructureLevel *pLvl;
  Fts5IndexIter *pNew;





  assert( (pTerm==0 && nTerm==0) || iLevel<0 );

  /* Allocate space for the new multi-seg-iterator. */
  if( p->rc==SQLITE_OK ){
    if( iLevel<0 ){
      assert( pStruct->nSegment==fts5StructureCountSegments(pStruct) );
      nSeg = pStruct->nSegment;
      nSeg += (p->pHash ? 1 : 0);
    }else{
      nSeg = MIN(pStruct->aLevel[iLevel].nSeg, nSegment);
    }





  }
  *ppOut = pNew = fts5MultiIterAlloc(p, nSeg);
  if( pNew==0 ) return;
  pNew->bRev = (0!=(flags & FTS5INDEX_QUERY_DESC));
  pNew->bSkipEmpty = (u8)bSkipEmpty;
  pNew->pStruct = pStruct;
  fts5StructureRef(pStruct);

  /* Initialize each of the component segment iterators. */
  if( iLevel<0 ){
    Fts5StructureLevel *pEnd = &pStruct->aLevel[pStruct->nLevel];
    if( p->pHash ){
      /* Add a segment iterator for the current contents of the hash table. */
      Fts5SegIter *pIter = &pNew->aSeg[iIter++];
      fts5SegIterHashInit(p, pTerm, nTerm, flags, pIter);






    }
    for(pLvl=&pStruct->aLevel[0]; pLvl<pEnd; pLvl++){
      for(iSeg=pLvl->nSeg-1; iSeg>=0; iSeg--){
        Fts5StructureSegment *pSeg = &pLvl->aSeg[iSeg];
        Fts5SegIter *pIter = &pNew->aSeg[iIter++];
        if( pTerm==0 ){
          fts5SegIterInit(p, pSeg, pIter);
        }else{
          fts5SegIterSeekInit(p, &buf, pTerm, nTerm, flags, pSeg, pIter);
        }







      }

    }
  }else{
    pLvl = &pStruct->aLevel[iLevel];
    for(iSeg=nSeg-1; iSeg>=0; iSeg--){
      fts5SegIterInit(p, &pLvl->aSeg[iSeg], &pNew->aSeg[iIter++]);
    }
  }
  assert( iIter==nSeg );

  /* If the above was successful, each component iterators now points 
  ** to the first entry in its segment. In this case initialize the 
  ** aFirst[] array. Or, if an error has occurred, free the iterator
  ** object and set the output variable to NULL.  */
  if( p->rc==SQLITE_OK ){
    for(iIter=pNew->nSeg-1; iIter>0; iIter--){











      int iEq;
      if( (iEq = fts5MultiIterDoCompare(pNew, iIter)) ){
        fts5SegIterNext(p, &pNew->aSeg[iEq], 0);
        fts5MultiIterAdvanced(p, pNew, iEq, iIter);






      }
    }
    fts5MultiIterSetEof(pNew);
    fts5AssertMultiIterSetup(p, pNew);

    if( pNew->bSkipEmpty && fts5MultiIterIsEmpty(p, pNew) ){
      fts5MultiIterNext(p, pNew, 0, 0);
    }
  }else{
    fts5MultiIterFree(p, pNew);
    *ppOut = 0;
  }
  fts5BufferFree(&buf);
}

/*
** Create an Fts5IndexIter that iterates through the doclist provided
** as the second argument.
*/
static void fts5MultiIterNew2(
  Fts5Index *p,                   /* FTS5 backend to iterate within */
  Fts5Data *pData,                /* Doclist to iterate through */
  int bDesc,                      /* True for descending rowid order */
  Fts5IndexIter **ppOut           /* New object */



){
  Fts5IndexIter *pNew;
  pNew = fts5MultiIterAlloc(p, 2);
  if( pNew ){
    Fts5SegIter *pIter = &pNew->aSeg[1];









    pNew->bFiltered = 1;
    pIter->flags = FTS5_SEGITER_ONETERM;
    if( pData->szLeaf>0 ){
      pIter->pLeaf = pData;
      pIter->iLeafOffset = fts5GetVarint(pData->p, (u64*)&pIter->iRowid);
      pIter->iEndofDoclist = pData->nn;
      pNew->aFirst[1].iFirst = 1;
      if( bDesc ){
        pNew->bRev = 1;
        pIter->flags |= FTS5_SEGITER_REVERSE;
        fts5SegIterReverseInitPage(p, pIter);






      }else{
        fts5SegIterLoadNPos(p, pIter);
      }
      pData = 0;
    }else{
      pNew->bEof = 1;
    }

    *ppOut = pNew;
  }





  fts5DataRelease(pData);


}













/*
** Return true if the iterator is at EOF or if an error has occurred. 
** False otherwise.
*/
static int fts5MultiIterEof(Fts5Index *p, Fts5IndexIter *pIter){
  assert( p->rc 
      || (pIter->aSeg[ pIter->aFirst[1].iFirst ].pLeaf==0)==pIter->bEof 
  );
  return (p->rc || pIter->bEof);
}

/*
** Return the rowid of the entry that the iterator currently points
** to. If the iterator points to EOF when this function is called the
** results are undefined.
*/
static i64 fts5MultiIterRowid(Fts5IndexIter *pIter){
  assert( pIter->aSeg[ pIter->aFirst[1].iFirst ].pLeaf );
  return pIter->aSeg[ pIter->aFirst[1].iFirst ].iRowid;
}

/*
** Move the iterator to the next entry at or following iMatch.
*/
static void fts5MultiIterNextFrom(
  Fts5Index *p, 
  Fts5IndexIter *pIter, 
  i64 iMatch
){
  while( 1 ){
    i64 iRowid;
    fts5MultiIterNext(p, pIter, 1, iMatch);
    if( fts5MultiIterEof(p, pIter) ) break;
    iRowid = fts5MultiIterRowid(pIter);
    if( pIter->bRev==0 && iRowid>=iMatch ) break;
    if( pIter->bRev!=0 && iRowid<=iMatch ) break;
  }
}

/*
** Return a pointer to a buffer containing the term associated with the 
** entry that the iterator currently points to.
*/
static const u8 *fts5MultiIterTerm(Fts5IndexIter *pIter, int *pn){
  Fts5SegIter *p = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
  *pn = p->term.n;
  return p->term.p;
}

static void fts5ChunkIterate(
  Fts5Index *p,                   /* Index object */
  Fts5SegIter *pSeg,              /* Poslist of this iterator */
  void *pCtx,                     /* Context pointer for xChunk callback */
  void (*xChunk)(Fts5Index*, void*, const u8*, int)
................................................................................
){
  int nRem = pSeg->nPos;          /* Number of bytes still to come */
  Fts5Data *pData = 0;
  u8 *pChunk = &pSeg->pLeaf->p[pSeg->iLeafOffset];
  int nChunk = MIN(nRem, pSeg->pLeaf->szLeaf - pSeg->iLeafOffset);
  int pgno = pSeg->iLeafPgno;
  int pgnoSave = 0;




  if( (pSeg->flags & FTS5_SEGITER_REVERSE)==0 ){
    pgnoSave = pgno+1;
  }

  while( 1 ){
    xChunk(p, pCtx, pChunk, nChunk);
................................................................................
        pSeg->pNextLeaf = pData;
        pData = 0;
      }
    }
  }
}



































































































































































































































































































































































































































































/*
** Allocate a new segment-id for the structure pStruct. The new segment
** id must be between 1 and 65335 inclusive, and must not be used by 
** any currently existing segment. If a free segment id cannot be found,
** SQLITE_FULL is returned.
**
................................................................................
  if( p->pHash ){
    sqlite3Fts5HashClear(p->pHash);
    p->nPendingData = 0;
  }
}

/*
** Return the size of the prefix, in bytes, that buffer (nNew/pNew) shares
** with buffer (nOld/pOld).



*/
static int fts5PrefixCompress(
  int nOld, const u8 *pOld,
  int nNew, const u8 *pNew
){
  int i;
  assert( fts5BlobCompare(pOld, nOld, pNew, nNew)<0 );
  for(i=0; i<nOld; i++){
    if( pOld[i]!=pNew[i] ) break;
  }
  return i;
}

static void fts5WriteDlidxClear(
................................................................................
      ** Usually, the previous term is available in pPage->term. The exception
      ** is if this is the first term written in an incremental-merge step.
      ** In this case the previous term is not available, so just write a
      ** copy of (pTerm/nTerm) into the parent node. This is slightly
      ** inefficient, but still correct.  */
      int n = nTerm;
      if( pPage->term.n ){
        n = 1 + fts5PrefixCompress(pPage->term.n, pPage->term.p, nTerm, pTerm);
      }
      fts5WriteBtreeTerm(p, pWriter, n, pTerm);
      pPage = &pWriter->writer;
    }
  }else{
    nPrefix = fts5PrefixCompress(pPage->term.n, pPage->term.p, nTerm, pTerm);
    fts5BufferAppendVarint(&p->rc, &pPage->buf, nPrefix);
  }

  /* Append the number of bytes of new data, then the term data itself
  ** to the page. */
  fts5BufferAppendVarint(&p->rc, &pPage->buf, nTerm - nPrefix);
  fts5BufferAppendBlob(&p->rc, &pPage->buf, nTerm - nPrefix, &pTerm[nPrefix]);
................................................................................

/*
** Append a rowid and position-list size field to the writers output. 
*/
static void fts5WriteAppendRowid(
  Fts5Index *p, 
  Fts5SegWriter *pWriter,
  i64 iRowid,
  int nPos
){
  if( p->rc==SQLITE_OK ){
    Fts5PageWriter *pPage = &pWriter->writer;

    if( (pPage->buf.n + pPage->pgidx.n)>=p->pConfig->pgsz ){
      fts5WriteFlushLeaf(p, pWriter);
    }
................................................................................
    }else{
      assert( p->rc || iRowid>pWriter->iPrevRowid );
      fts5BufferAppendVarint(&p->rc, &pPage->buf, iRowid - pWriter->iPrevRowid);
    }
    pWriter->iPrevRowid = iRowid;
    pWriter->bFirstRowidInDoclist = 0;
    pWriter->bFirstRowidInPage = 0;

    fts5BufferAppendVarint(&p->rc, &pPage->buf, nPos);
  }
}

static void fts5WriteAppendPoslistData(
  Fts5Index *p, 
  Fts5SegWriter *pWriter, 
  const u8 *aData, 
................................................................................
}

/*
** Iterator pIter was used to iterate through the input segments of on an
** incremental merge operation. This function is called if the incremental
** merge step has finished but the input has not been completely exhausted.
*/
static void fts5TrimSegments(Fts5Index *p, Fts5IndexIter *pIter){
  int i;
  Fts5Buffer buf;
  memset(&buf, 0, sizeof(Fts5Buffer));
  for(i=0; i<pIter->nSeg; i++){
    Fts5SegIter *pSeg = &pIter->aSeg[i];
    if( pSeg->pSeg==0 ){
      /* no-op */
................................................................................
  Fts5Structure **ppStruct,       /* IN/OUT: Stucture of index */
  int iLvl,                       /* Level to read input from */
  int *pnRem                      /* Write up to this many output leaves */
){
  Fts5Structure *pStruct = *ppStruct;
  Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
  Fts5StructureLevel *pLvlOut;
  Fts5IndexIter *pIter = 0;       /* Iterator to read input data */
  int nRem = pnRem ? *pnRem : 0;  /* Output leaf pages left to write */
  int nInput;                     /* Number of input segments */
  Fts5SegWriter writer;           /* Writer object */
  Fts5StructureSegment *pSeg;     /* Output segment */
  Fts5Buffer term;
  int bOldest;                    /* True if the output segment is the oldest */



  assert( iLvl<pStruct->nLevel );
  assert( pLvl->nMerge<=pLvl->nSeg );

  memset(&writer, 0, sizeof(Fts5SegWriter));
  memset(&term, 0, sizeof(Fts5Buffer));
  if( pLvl->nMerge ){
................................................................................

    /* Read input from all segments in the input level */
    nInput = pLvl->nSeg;
  }
  bOldest = (pLvlOut->nSeg==1 && pStruct->nLevel==iLvl+2);

  assert( iLvl>=0 );
  for(fts5MultiIterNew(p, pStruct, 0, 0, 0, 0, iLvl, nInput, &pIter);
      fts5MultiIterEof(p, pIter)==0;
      fts5MultiIterNext(p, pIter, 0, 0)
  ){
    Fts5SegIter *pSegIter = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
    int nPos;                     /* position-list size field value */
    int nTerm;
    const u8 *pTerm;
................................................................................
      /* This is a new term. Append a term to the output segment. */
      fts5WriteAppendTerm(p, &writer, nTerm, pTerm);
      fts5BufferSet(&p->rc, &term, nTerm, pTerm);
    }

    /* Append the rowid to the output */
    /* WRITEPOSLISTSIZE */
    nPos = pSegIter->nPos*2 + pSegIter->bDel;
    fts5WriteAppendRowid(p, &writer, fts5MultiIterRowid(pIter), nPos);









    /* Append the position-list data to the output */


    fts5ChunkIterate(p, pSegIter, (void*)&writer, fts5MergeChunkCallback);

  }

  /* Flush the last leaf page to disk. Set the output segment b-tree height
  ** and last leaf page number at the same time.  */
  fts5WriteFinish(p, &writer, &pSeg->pgnoLast);

  if( fts5MultiIterEof(p, pIter) ){
................................................................................
    }
  }else{
    assert( pSeg->pgnoLast>0 );
    fts5TrimSegments(p, pIter);
    pLvl->nMerge = nInput;
  }

  fts5MultiIterFree(p, pIter);
  fts5BufferFree(&term);
  if( pnRem ) *pnRem -= writer.nLeafWritten;
}

/*
** Do up to nPg pages of automerge work on the index.
*/
................................................................................
  /* Obtain a reference to the index structure and allocate a new segment-id
  ** for the new level-0 segment.  */
  pStruct = fts5StructureRead(p);
  iSegid = fts5AllocateSegid(p, pStruct);

  if( iSegid ){
    const int pgsz = p->pConfig->pgsz;

    Fts5StructureSegment *pSeg;   /* New segment within pStruct */
    Fts5Buffer *pBuf;             /* Buffer in which to assemble leaf page */
    Fts5Buffer *pPgidx;           /* Buffer in which to assemble pgidx */

    Fts5SegWriter writer;
    fts5WriteInit(p, &writer, iSegid);

................................................................................
        i64 iDelta = 0;
        int iOff = 0;

        /* The entire doclist will not fit on this leaf. The following 
        ** loop iterates through the poslists that make up the current 
        ** doclist.  */
        while( p->rc==SQLITE_OK && iOff<nDoclist ){
          int nPos;
          int nCopy;
          int bDummy;
          iOff += fts5GetVarint(&pDoclist[iOff], (u64*)&iDelta);
          nCopy = fts5GetPoslistSize(&pDoclist[iOff], &nPos, &bDummy);
          nCopy += nPos;
          iRowid += iDelta;
          
          if( writer.bFirstRowidInPage ){
            fts5PutU16(&pBuf->p[0], (u16)pBuf->n);   /* first rowid on page */
            pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iRowid);
            writer.bFirstRowidInPage = 0;
            fts5WriteDlidxAppend(p, &writer, iRowid);
          }else{
            pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iDelta);
          }
          assert( pBuf->n<=pBuf->nSpace );


















          if( (pBuf->n + pPgidx->n + nCopy) <= pgsz ){
            /* The entire poslist will fit on the current leaf. So copy
            ** it in one go. */
            fts5BufferSafeAppendBlob(pBuf, &pDoclist[iOff], nCopy);
          }else{
            /* The entire poslist will not fit on this leaf. So it needs
            ** to be broken into sections. The only qualification being
            ** that each varint must be stored contiguously.  */
            const u8 *pPoslist = &pDoclist[iOff];
            int iPos = 0;
            while( p->rc==SQLITE_OK ){
              int nSpace = pgsz - pBuf->n - pPgidx->n;
              int n = 0;
              if( (nCopy - iPos)<=nSpace ){
                n = nCopy - iPos;
              }else{
                n = fts5PoslistPrefix(&pPoslist[iPos], nSpace);
              }
              assert( n>0 );
              fts5BufferSafeAppendBlob(pBuf, &pPoslist[iPos], n);
              iPos += n;
              if( (pBuf->n + pPgidx->n)>=pgsz ){
                fts5WriteFlushLeaf(p, &writer);
              }
              if( iPos>=nCopy ) break;
            }
          }
          iOff += nCopy;

        }
      }

      /* TODO2: Doclist terminator written here. */
      /* pBuf->p[pBuf->n++] = '\0'; */
      assert( pBuf->n<=pBuf->nSpace );
      sqlite3Fts5HashScanNext(pHash);
................................................................................
    fts5StructureWrite(p, pStruct);
  }
  fts5StructureRelease(pStruct);

  return fts5IndexReturn(p);
}

static void fts5PoslistCallback(
  Fts5Index *p, 
  void *pContext, 
  const u8 *pChunk, int nChunk
){
  assert_nc( nChunk>=0 );
  if( nChunk>0 ){
    fts5BufferSafeAppendBlob((Fts5Buffer*)pContext, pChunk, nChunk);
  }
}

typedef struct PoslistCallbackCtx PoslistCallbackCtx;
struct PoslistCallbackCtx {
  Fts5Buffer *pBuf;               /* Append to this buffer */
  Fts5Colset *pColset;            /* Restrict matches to this column */
  int eState;                     /* See above */
};

/*
** TODO: Make this more efficient!
*/
static int fts5IndexColsetTest(Fts5Colset *pColset, int iCol){
  int i;
  for(i=0; i<pColset->nCol; i++){
    if( pColset->aiCol[i]==iCol ) return 1;
  }
  return 0;
}

static void fts5PoslistFilterCallback(
  Fts5Index *p, 
  void *pContext, 
  const u8 *pChunk, int nChunk
){
  PoslistCallbackCtx *pCtx = (PoslistCallbackCtx*)pContext;
  assert_nc( nChunk>=0 );
  if( nChunk>0 ){
    /* Search through to find the first varint with value 1. This is the
    ** start of the next columns hits. */
    int i = 0;
    int iStart = 0;

    if( pCtx->eState==2 ){
      int iCol;
      fts5FastGetVarint32(pChunk, i, iCol);
      if( fts5IndexColsetTest(pCtx->pColset, iCol) ){
        pCtx->eState = 1;
        fts5BufferSafeAppendVarint(pCtx->pBuf, 1);
      }else{
        pCtx->eState = 0;
      }
    }

    do {
      while( i<nChunk && pChunk[i]!=0x01 ){
        while( pChunk[i] & 0x80 ) i++;
        i++;
      }
      if( pCtx->eState ){
        fts5BufferSafeAppendBlob(pCtx->pBuf, &pChunk[iStart], i-iStart);
      }
      if( i<nChunk ){
        int iCol;
        iStart = i;
        i++;
        if( i>=nChunk ){
          pCtx->eState = 2;
        }else{
          fts5FastGetVarint32(pChunk, i, iCol);
          pCtx->eState = fts5IndexColsetTest(pCtx->pColset, iCol);
          if( pCtx->eState ){
            fts5BufferSafeAppendBlob(pCtx->pBuf, &pChunk[iStart], i-iStart);
            iStart = i;
          }
        }
      }
    }while( i<nChunk );
  }
}

/*
** Iterator pIter currently points to a valid entry (not EOF). This
** function appends the position list data for the current entry to
** buffer pBuf. It does not make a copy of the position-list size
** field.
*/
static void fts5SegiterPoslist(
  Fts5Index *p,
  Fts5SegIter *pSeg,
  Fts5Colset *pColset,
  Fts5Buffer *pBuf
){
  if( 0==fts5BufferGrow(&p->rc, pBuf, pSeg->nPos) ){
    if( pColset==0 ){
      fts5ChunkIterate(p, pSeg, (void*)pBuf, fts5PoslistCallback);
    }else{
      PoslistCallbackCtx sCtx;
      sCtx.pBuf = pBuf;
      sCtx.pColset = pColset;
      sCtx.eState = fts5IndexColsetTest(pColset, 0);
      assert( sCtx.eState==0 || sCtx.eState==1 );
      fts5ChunkIterate(p, pSeg, (void*)&sCtx, fts5PoslistFilterCallback);


    }
  }
}

/*
** IN/OUT parameter (*pa) points to a position list n bytes in size. If
** the position list contains entries for column iCol, then (*pa) is set
** to point to the sub-position-list for that column and the number of
** bytes in it returned. Or, if the argument position list does not
** contain any entries for column iCol, return 0.
*/
static int fts5IndexExtractCol(
  const u8 **pa,                  /* IN/OUT: Pointer to poslist */
  int n,                          /* IN: Size of poslist in bytes */
  int iCol                        /* Column to extract from poslist */
){
  int iCurrent = 0;               /* Anything before the first 0x01 is col 0 */
  const u8 *p = *pa;
  const u8 *pEnd = &p[n];         /* One byte past end of position list */
  u8 prev = 0;

  while( iCol>iCurrent ){
    /* Advance pointer p until it points to pEnd or an 0x01 byte that is
    ** not part of a varint */
    while( (prev & 0x80) || *p!=0x01 ){
      prev = *p++;
      if( p==pEnd ) return 0;
    }
    *pa = p++;
    p += fts5GetVarint32(p, iCurrent);
  }
  if( iCol!=iCurrent ) return 0;

  /* Advance pointer p until it points to pEnd or an 0x01 byte that is
  ** not part of a varint */
  assert( (prev & 0x80)==0 );
  while( p<pEnd && ((prev & 0x80) || *p!=0x01) ){
    prev = *p++;
  }
  return p - (*pa);
}


/*
** Iterator pMulti currently points to a valid entry (not EOF). This
** function appends the following to buffer pBuf:
**
**   * The varint iDelta, and
**   * the position list that currently points to, including the size field.
**
** If argument pColset is NULL, then the position list is filtered according
** to pColset before being appended to the buffer. If this means there are
** no entries in the position list, nothing is appended to the buffer (not
** even iDelta).
**
** If an error occurs, an error code is left in p->rc. 
*/
static int fts5AppendPoslist(
  Fts5Index *p,
  i64 iDelta,
  Fts5IndexIter *pMulti,
  Fts5Colset *pColset,
  Fts5Buffer *pBuf
){
  if( p->rc==SQLITE_OK ){
    Fts5SegIter *pSeg = &pMulti->aSeg[ pMulti->aFirst[1].iFirst ];
    assert( fts5MultiIterEof(p, pMulti)==0 );

    assert( pSeg->nPos>0 );
    if( 0==fts5BufferGrow(&p->rc, pBuf, pSeg->nPos+9+9) ){

      if( pSeg->iLeafOffset+pSeg->nPos<=pSeg->pLeaf->szLeaf 
       && (pColset==0 || pColset->nCol==1)
      ){
        const u8 *pPos = &pSeg->pLeaf->p[pSeg->iLeafOffset];
        int nPos;
        if( pColset ){
          nPos = fts5IndexExtractCol(&pPos, pSeg->nPos, pColset->aiCol[0]);
          if( nPos==0 ) return 1;
        }else{
          nPos = pSeg->nPos;
        }
        assert( nPos>0 );
        fts5BufferSafeAppendVarint(pBuf, iDelta);
        fts5BufferSafeAppendVarint(pBuf, nPos*2);
        fts5BufferSafeAppendBlob(pBuf, pPos, nPos);
      }else{
        int iSv1;
        int iSv2;
        int iData;

        /* Append iDelta */
        iSv1 = pBuf->n;
        fts5BufferSafeAppendVarint(pBuf, iDelta);

        /* WRITEPOSLISTSIZE */
        iSv2 = pBuf->n;
        fts5BufferSafeAppendVarint(pBuf, pSeg->nPos*2);
        iData = pBuf->n;

        fts5SegiterPoslist(p, pSeg, pColset, pBuf);

        if( pColset ){
          int nActual = pBuf->n - iData;
          if( nActual!=pSeg->nPos ){
            if( nActual==0 ){
              pBuf->n = iSv1;
              return 1;
            }else{
              int nReq = sqlite3Fts5GetVarintLen((u32)(nActual*2));
              while( iSv2<(iData-nReq) ){ pBuf->p[iSv2++] = 0x80; }
              sqlite3Fts5PutVarint(&pBuf->p[iSv2], nActual*2);
            }
          }
        }
      }

    }
  }

  return 0;
}

static void fts5DoclistIterNext(Fts5DoclistIter *pIter){
  u8 *p = pIter->aPoslist + pIter->nSize + pIter->nPoslist;

  assert( pIter->aPoslist );
  if( p>=pIter->aEof ){
    pIter->aPoslist = 0;
................................................................................
#endif

#define fts5MergeAppendDocid(pBuf, iLastRowid, iRowid) {       \
  assert( (pBuf)->n!=0 || (iLastRowid)==0 );                   \
  fts5BufferSafeAppendVarint((pBuf), (iRowid) - (iLastRowid)); \
  (iLastRowid) = (iRowid);                                     \
}
































































/*
** Buffers p1 and p2 contain doclists. This function merges the content
** of the two doclists together and sets buffer p1 to the result before
** returning.
**
** If an error occurs, an error code is left in p->rc. If an error has
................................................................................
  Fts5Buffer *p1,                 /* First list to merge */
  Fts5Buffer *p2                  /* Second list to merge */
){
  if( p2->n ){
    i64 iLastRowid = 0;
    Fts5DoclistIter i1;
    Fts5DoclistIter i2;
    Fts5Buffer out;
    Fts5Buffer tmp;
    memset(&out, 0, sizeof(out));
    memset(&tmp, 0, sizeof(tmp));

    sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n);
    fts5DoclistIterInit(p1, &i1);
    fts5DoclistIterInit(p2, &i2);
    while( p->rc==SQLITE_OK && (i1.aPoslist!=0 || i2.aPoslist!=0) ){


      if( i2.aPoslist==0 || (i1.aPoslist && i1.iRowid<i2.iRowid) ){
        /* Copy entry from i1 */
        fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
        fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.nPoslist+i1.nSize);
        fts5DoclistIterNext(&i1);

      }
      else if( i1.aPoslist==0 || i2.iRowid!=i1.iRowid ){
        /* Copy entry from i2 */
        fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
        fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.nPoslist+i2.nSize);
        fts5DoclistIterNext(&i2);

      }
      else{

        i64 iPos1 = 0;
        i64 iPos2 = 0;
        int iOff1 = 0;
        int iOff2 = 0;
        u8 *a1 = &i1.aPoslist[i1.nSize];
        u8 *a2 = &i2.aPoslist[i2.nSize];


        Fts5PoslistWriter writer;
        memset(&writer, 0, sizeof(writer));

        /* Merge the two position lists. */ 
        fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
        fts5BufferZero(&tmp);



        sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
        sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);


        while( p->rc==SQLITE_OK && (iPos1>=0 || iPos2>=0) ){
          i64 iNew;
          if( iPos2<0 || (iPos1>=0 && iPos1<iPos2) ){
            iNew = iPos1;

            sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
          }else{
            iNew = iPos2;

            sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);




            if( iPos1==iPos2 ){



              sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1,&iPos1);






            }
          }
          p->rc = sqlite3Fts5PoslistWriterAppend(&tmp, &writer, iNew);











        }

        /* WRITEPOSLISTSIZE */
        fts5BufferSafeAppendVarint(&out, tmp.n * 2);
        fts5BufferSafeAppendBlob(&out, tmp.p, tmp.n);
        fts5DoclistIterNext(&i1);
        fts5DoclistIterNext(&i2);

      }
    }










    fts5BufferSet(&p->rc, p1, out.n, out.p);
    fts5BufferFree(&tmp);
    fts5BufferFree(&out);
  }
}

static void fts5BufferSwap(Fts5Buffer *p1, Fts5Buffer *p2){
  Fts5Buffer tmp = *p1;
  *p1 = *p2;
  *p2 = tmp;
}

static void fts5SetupPrefixIter(
  Fts5Index *p,                   /* Index to read from */
  int bDesc,                      /* True for "ORDER BY rowid DESC" */
  const u8 *pToken,               /* Buffer containing prefix to match */
  int nToken,                     /* Size of buffer pToken in bytes */
  Fts5Colset *pColset,            /* Restrict matches to these columns */
  Fts5IndexIter **ppIter          /* OUT: New iterator */
){
  Fts5Structure *pStruct;
  Fts5Buffer *aBuf;
  const int nBuf = 32;











  aBuf = (Fts5Buffer*)fts5IdxMalloc(p, sizeof(Fts5Buffer)*nBuf);
  pStruct = fts5StructureRead(p);

  if( aBuf && pStruct ){
    const int flags = FTS5INDEX_QUERY_SCAN;


    int i;
    i64 iLastRowid = 0;
    Fts5IndexIter *p1 = 0;     /* Iterator used to gather data from index */
    Fts5Data *pData;
    Fts5Buffer doclist;
    int bNewTerm = 1;

    memset(&doclist, 0, sizeof(doclist));
    for(fts5MultiIterNew(p, pStruct, 1, flags, pToken, nToken, -1, 0, &p1);


        fts5MultiIterEof(p, p1)==0;
        fts5MultiIterNext2(p, p1, &bNewTerm)
    ){
      i64 iRowid = fts5MultiIterRowid(p1);
      int nTerm;
      const u8 *pTerm = fts5MultiIterTerm(p1, &nTerm);


      assert_nc( memcmp(pToken, pTerm, MIN(nToken, nTerm))<=0 );
      if( bNewTerm ){
        if( nTerm<nToken || memcmp(pToken, pTerm, nToken) ) break;
      }



      if( doclist.n>0 && iRowid<=iLastRowid ){
        for(i=0; p->rc==SQLITE_OK && doclist.n; i++){
          assert( i<nBuf );
          if( aBuf[i].n==0 ){
            fts5BufferSwap(&doclist, &aBuf[i]);
            fts5BufferZero(&doclist);
          }else{
            fts5MergePrefixLists(p, &doclist, &aBuf[i]);
            fts5BufferZero(&aBuf[i]);
          }
        }
        iLastRowid = 0;
      }

      if( !fts5AppendPoslist(p, iRowid-iLastRowid, p1, pColset, &doclist) ){
        iLastRowid = iRowid;
      }
    }

    for(i=0; i<nBuf; i++){
      if( p->rc==SQLITE_OK ){
        fts5MergePrefixLists(p, &doclist, &aBuf[i]);
      }
      fts5BufferFree(&aBuf[i]);
    }
    fts5MultiIterFree(p, p1);

    pData = fts5IdxMalloc(p, sizeof(Fts5Data) + doclist.n);
    if( pData ){
      pData->p = (u8*)&pData[1];
      pData->nn = pData->szLeaf = doclist.n;
      memcpy(pData->p, doclist.p, doclist.n);
      fts5MultiIterNew2(p, pData, bDesc, ppIter);
................................................................................
** to the document with rowid iRowid.
*/
static int sqlite3Fts5IndexBeginWrite(Fts5Index *p, int bDelete, i64 iRowid){
  assert( p->rc==SQLITE_OK );

  /* Allocate the hash table if it has not already been allocated */
  if( p->pHash==0 ){
    p->rc = sqlite3Fts5HashNew(&p->pHash, &p->nPendingData);
  }

  /* Flush the hash table to disk if required */
  if( iRowid<p->iWriteRowid 
   || (iRowid==p->iWriteRowid && p->bDelete==0)
   || (p->nPendingData > p->pConfig->nHashSize) 
  ){
................................................................................
** to the database. Additionally, assume that the contents of the %_data
** table may have changed on disk. So any in-memory caches of %_data 
** records must be invalidated.
*/
static int sqlite3Fts5IndexRollback(Fts5Index *p){
  fts5CloseReader(p);
  fts5IndexDiscardData(p);
  assert( p->rc==SQLITE_OK );
  return SQLITE_OK;
}

/*
** The %_data table is completely empty when this function is called. This
** function populates it with the initial structure objects for each index,
** and the initial version of the "averages" record (a zero-byte blob).
................................................................................
}

/*
** Argument p points to a buffer containing utf-8 text that is n bytes in 
** size. Return the number of bytes in the nChar character prefix of the
** buffer, or 0 if there are less than nChar characters in total.
*/
static int fts5IndexCharlenToBytelen(const char *p, int nByte, int nChar){




  int n = 0;
  int i;
  for(i=0; i<nChar; i++){
    if( n>=nByte ) return 0;      /* Input contains fewer than nChar chars */
    if( (unsigned char)p[n++]>=0xc0 ){
      while( (p[n] & 0xc0)==0x80 ) n++;
    }
................................................................................

  /* Add the entry to the main terms index. */
  rc = sqlite3Fts5HashWrite(
      p->pHash, p->iWriteRowid, iCol, iPos, FTS5_MAIN_PREFIX, pToken, nToken
  );

  for(i=0; i<pConfig->nPrefix && rc==SQLITE_OK; i++){

    int nByte = fts5IndexCharlenToBytelen(pToken, nToken, pConfig->aPrefix[i]);
    if( nByte ){
      rc = sqlite3Fts5HashWrite(p->pHash, 
          p->iWriteRowid, iCol, iPos, (char)(FTS5_MAIN_PREFIX+i+1), pToken,
          nByte
      );
    }
  }
................................................................................
  Fts5Index *p,                   /* FTS index to query */
  const char *pToken, int nToken, /* Token (or prefix) to query for */
  int flags,                      /* Mask of FTS5INDEX_QUERY_X flags */
  Fts5Colset *pColset,            /* Match these columns only */
  Fts5IndexIter **ppIter          /* OUT: New iterator object */
){
  Fts5Config *pConfig = p->pConfig;
  Fts5IndexIter *pRet = 0;
  int iIdx = 0;
  Fts5Buffer buf = {0, 0, 0};

  /* If the QUERY_SCAN flag is set, all other flags must be clear. */
  assert( (flags & FTS5INDEX_QUERY_SCAN)==0 || flags==FTS5INDEX_QUERY_SCAN );

  if( sqlite3Fts5BufferSize(&p->rc, &buf, nToken+1)==0 ){

    memcpy(&buf.p[1], pToken, nToken);

#ifdef SQLITE_DEBUG





    /* If the QUERY_TEST_NOIDX flag was specified, then this must be a
    ** prefix-query. Instead of using a prefix-index (if one exists), 
    ** evaluate the prefix query using the main FTS index. This is used
    ** for internal sanity checking by the integrity-check in debug 
    ** mode only.  */

    if( pConfig->bPrefixIndex==0 || (flags & FTS5INDEX_QUERY_TEST_NOIDX) ){
      assert( flags & FTS5INDEX_QUERY_PREFIX );
      iIdx = 1+pConfig->nPrefix;
    }else
#endif
    if( flags & FTS5INDEX_QUERY_PREFIX ){
      int nChar = fts5IndexCharlen(pToken, nToken);
      for(iIdx=1; iIdx<=pConfig->nPrefix; iIdx++){
        if( pConfig->aPrefix[iIdx-1]==nChar ) break;
      }
    }

    if( iIdx<=pConfig->nPrefix ){

      Fts5Structure *pStruct = fts5StructureRead(p);
      buf.p[0] = (u8)(FTS5_MAIN_PREFIX + iIdx);
      if( pStruct ){

        fts5MultiIterNew(p, pStruct, 1, flags, buf.p, nToken+1, -1, 0, &pRet);

        fts5StructureRelease(pStruct);
      }
    }else{

      int bDesc = (flags & FTS5INDEX_QUERY_DESC)!=0;
      buf.p[0] = FTS5_MAIN_PREFIX;
      fts5SetupPrefixIter(p, bDesc, buf.p, nToken+1, pColset, &pRet);






    }

    if( p->rc ){
      sqlite3Fts5IterClose(pRet);
      pRet = 0;
      fts5CloseReader(p);
    }

    *ppIter = pRet;
    sqlite3Fts5BufferFree(&buf);
  }
  return fts5IndexReturn(p);
}

/*
** Return true if the iterator passed as the only argument is at EOF.
*/
static int sqlite3Fts5IterEof(Fts5IndexIter *pIter){
  assert( pIter->pIndex->rc==SQLITE_OK );
  return pIter->bEof;
}

/*
** Move to the next matching rowid. 
*/
static int sqlite3Fts5IterNext(Fts5IndexIter *pIter){

  assert( pIter->pIndex->rc==SQLITE_OK );
  fts5MultiIterNext(pIter->pIndex, pIter, 0, 0);
  return fts5IndexReturn(pIter->pIndex);
}

/*
** Move to the next matching term/rowid. Used by the fts5vocab module.
*/
static int sqlite3Fts5IterNextScan(Fts5IndexIter *pIter){

  Fts5Index *p = pIter->pIndex;

  assert( pIter->pIndex->rc==SQLITE_OK );

  fts5MultiIterNext(p, pIter, 0, 0);
  if( p->rc==SQLITE_OK ){
    Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
    if( pSeg->pLeaf && pSeg->term.p[0]!=FTS5_MAIN_PREFIX ){
      fts5DataRelease(pSeg->pLeaf);
      pSeg->pLeaf = 0;
      pIter->bEof = 1;
    }
  }

  return fts5IndexReturn(pIter->pIndex);
}

/*
** Move to the next matching rowid that occurs at or after iMatch. The
** definition of "at or after" depends on whether this iterator iterates
** in ascending or descending rowid order.
*/
static int sqlite3Fts5IterNextFrom(Fts5IndexIter *pIter, i64 iMatch){

  fts5MultiIterNextFrom(pIter->pIndex, pIter, iMatch);
  return fts5IndexReturn(pIter->pIndex);
}

/*
** Return the current rowid.
*/
static i64 sqlite3Fts5IterRowid(Fts5IndexIter *pIter){
  return fts5MultiIterRowid(pIter);
}

/*
** Return the current term.
*/
static const char *sqlite3Fts5IterTerm(Fts5IndexIter *pIter, int *pn){
  int n;
  const char *z = (const char*)fts5MultiIterTerm(pIter, &n);
  *pn = n-1;
  return &z[1];
}


static int fts5IndexExtractColset (
  Fts5Colset *pColset,            /* Colset to filter on */
  const u8 *pPos, int nPos,       /* Position list */
  Fts5Buffer *pBuf                /* Output buffer */
){
  int rc = SQLITE_OK;
  int i;

  fts5BufferZero(pBuf);
  for(i=0; i<pColset->nCol; i++){
    const u8 *pSub = pPos;
    int nSub = fts5IndexExtractCol(&pSub, nPos, pColset->aiCol[i]);
    if( nSub ){
      fts5BufferAppendBlob(&rc, pBuf, nSub, pSub);
    }
  }
  return rc;
}


/*
** Return a pointer to a buffer containing a copy of the position list for
** the current entry. Output variable *pn is set to the size of the buffer 
** in bytes before returning.
**
** The returned position list does not include the "number of bytes" varint
** field that starts the position list on disk.
*/
static int sqlite3Fts5IterPoslist(
  Fts5IndexIter *pIter, 
  Fts5Colset *pColset,            /* Column filter (or NULL) */
  const u8 **pp,                  /* OUT: Pointer to position-list data */
  int *pn,                        /* OUT: Size of position-list in bytes */
  i64 *piRowid                    /* OUT: Current rowid */
){
  Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
  assert( pIter->pIndex->rc==SQLITE_OK );
  *piRowid = pSeg->iRowid;
  if( pSeg->iLeafOffset+pSeg->nPos<=pSeg->pLeaf->szLeaf ){
    u8 *pPos = &pSeg->pLeaf->p[pSeg->iLeafOffset];
    if( pColset==0 || pIter->bFiltered ){
      *pn = pSeg->nPos;
      *pp = pPos;
    }else if( pColset->nCol==1 ){
      *pp = pPos;
      *pn = fts5IndexExtractCol(pp, pSeg->nPos, pColset->aiCol[0]);
    }else{
      fts5BufferZero(&pIter->poslist);
      fts5IndexExtractColset(pColset, pPos, pSeg->nPos, &pIter->poslist);
      *pp = pIter->poslist.p;
      *pn = pIter->poslist.n;
    }
  }else{
    fts5BufferZero(&pIter->poslist);
    fts5SegiterPoslist(pIter->pIndex, pSeg, pColset, &pIter->poslist);
    *pp = pIter->poslist.p;
    *pn = pIter->poslist.n;
  }
  return fts5IndexReturn(pIter->pIndex);
}

/*
** This function is similar to sqlite3Fts5IterPoslist(), except that it
** copies the position list into the buffer supplied as the second 
** argument.
*/
static int sqlite3Fts5IterPoslistBuffer(Fts5IndexIter *pIter, Fts5Buffer *pBuf){
  Fts5Index *p = pIter->pIndex;
  Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
  assert( p->rc==SQLITE_OK );
  fts5BufferZero(pBuf);
  fts5SegiterPoslist(p, pSeg, 0, pBuf);
  return fts5IndexReturn(p);
}

/*
** Close an iterator opened by an earlier call to sqlite3Fts5IndexQuery().
*/
static void sqlite3Fts5IterClose(Fts5IndexIter *pIter){
  if( pIter ){

    Fts5Index *pIndex = pIter->pIndex;
    fts5MultiIterFree(pIter->pIndex, pIter);
    fts5CloseReader(pIndex);
  }
}

/*
** Read and decode the "averages" record from the database. 
**
................................................................................
** Below this point is the implementation of the integrity-check 
** functionality.
*/

/*
** Return a simple checksum value based on the arguments.
*/
static u64 fts5IndexEntryCksum(
  i64 iRowid, 
  int iCol, 
  int iPos, 
  int iIdx,
  const char *pTerm,
  int nTerm
){
................................................................................
  Fts5Index *p,                   /* Fts5 index object */
  int iIdx,
  const char *z,                  /* Index key to query for */
  int n,                          /* Size of index key in bytes */
  int flags,                      /* Flags for Fts5IndexQuery */
  u64 *pCksum                     /* IN/OUT: Checksum value */
){

  u64 cksum = *pCksum;
  Fts5IndexIter *pIdxIter = 0;
  int rc = sqlite3Fts5IndexQuery(p, z, n, flags, 0, &pIdxIter);

  while( rc==SQLITE_OK && 0==sqlite3Fts5IterEof(pIdxIter) ){
    i64 dummy;
    const u8 *pPos;
    int nPos;

    i64 rowid = sqlite3Fts5IterRowid(pIdxIter);
    rc = sqlite3Fts5IterPoslist(pIdxIter, 0, &pPos, &nPos, &dummy);
    if( rc==SQLITE_OK ){

      Fts5PoslistReader sReader;
      for(sqlite3Fts5PoslistReaderInit(pPos, nPos, &sReader);
          sReader.bEof==0;
          sqlite3Fts5PoslistReaderNext(&sReader)
      ){
        int iCol = FTS5_POS2COLUMN(sReader.iPos);
        int iOff = FTS5_POS2OFFSET(sReader.iPos);
        cksum ^= fts5IndexEntryCksum(rowid, iCol, iOff, iIdx, z, n);
      }


      rc = sqlite3Fts5IterNext(pIdxIter);
    }
  }
  sqlite3Fts5IterClose(pIdxIter);

  *pCksum = cksum;
  return rc;
}


/*
................................................................................
#endif
}


/*
** Run internal checks to ensure that the FTS index (a) is internally 
** consistent and (b) contains entries for which the XOR of the checksums
** as calculated by fts5IndexEntryCksum() is cksum.
**
** Return SQLITE_CORRUPT if any of the internal checks fail, or if the
** checksum does not match. Return SQLITE_OK if all checks pass without
** error, or some other SQLite error code if another error (e.g. OOM)
** occurs.
*/
static int sqlite3Fts5IndexIntegrityCheck(Fts5Index *p, u64 cksum){

  u64 cksum2 = 0;                 /* Checksum based on contents of indexes */
  Fts5Buffer poslist = {0,0,0};   /* Buffer used to hold a poslist */
  Fts5IndexIter *pIter;           /* Used to iterate through entire index */
  Fts5Structure *pStruct;         /* Index structure */

#ifdef SQLITE_DEBUG
  /* Used by extra internal tests only run if NDEBUG is not defined */
  u64 cksum3 = 0;                 /* Checksum based on contents of indexes */
  Fts5Buffer term = {0,0,0};      /* Buffer used to hold most recent term */
#endif

  
  /* Load the FTS index structure */
  pStruct = fts5StructureRead(p);

  /* Check that the internal nodes of each segment match the leaves */
  if( pStruct ){
    int iLvl, iSeg;
................................................................................
  ** variable cksum2) based on entries extracted from the full-text index
  ** while doing a linear scan of each individual index in turn. 
  **
  ** As each term visited by the linear scans, a separate query for the
  ** same term is performed. cksum3 is calculated based on the entries
  ** extracted by these queries.
  */
  for(fts5MultiIterNew(p, pStruct, 0, 0, 0, 0, -1, 0, &pIter);
      fts5MultiIterEof(p, pIter)==0;
      fts5MultiIterNext(p, pIter, 0, 0)
  ){
    int n;                      /* Size of term in bytes */
    i64 iPos = 0;               /* Position read from poslist */
    int iOff = 0;               /* Offset within poslist */
    i64 iRowid = fts5MultiIterRowid(pIter);
    char *z = (char*)fts5MultiIterTerm(pIter, &n);

    /* If this is a new term, query for it. Update cksum3 with the results. */
    fts5TestTerm(p, &term, z, n, cksum2, &cksum3);






    poslist.n = 0;
    fts5SegiterPoslist(p, &pIter->aSeg[pIter->aFirst[1].iFirst] , 0, &poslist);
    while( 0==sqlite3Fts5PoslistNext64(poslist.p, poslist.n, &iOff, &iPos) ){
      int iCol = FTS5_POS2COLUMN(iPos);
      int iTokOff = FTS5_POS2OFFSET(iPos);
      cksum2 ^= fts5IndexEntryCksum(iRowid, iCol, iTokOff, -1, z, n);

    }
  }
  fts5TestTerm(p, &term, 0, 0, cksum2, &cksum3);

  fts5MultiIterFree(p, pIter);
  if( p->rc==SQLITE_OK && cksum!=cksum2 ) p->rc = FTS5_CORRUPT;

  fts5StructureRelease(pStruct);
#ifdef SQLITE_DEBUG
  fts5BufferFree(&term);
#endif
  fts5BufferFree(&poslist);
  return fts5IndexReturn(p);
}


/*
** Calculate and return a checksum that is the XOR of the index entry
** checksum of all entries that would be generated by the token specified
** by the final 5 arguments.
*/
static u64 sqlite3Fts5IndexCksum(
  Fts5Config *pConfig,            /* Configuration object */
  i64 iRowid,                     /* Document term appears in */
  int iCol,                       /* Column term appears in */
  int iPos,                       /* Position term appears in */
  const char *pTerm, int nTerm    /* Term at iPos */
){
  u64 ret = 0;                    /* Return value */
  int iIdx;                       /* For iterating through indexes */

  ret = fts5IndexEntryCksum(iRowid, iCol, iPos, 0, pTerm, nTerm);

  for(iIdx=0; iIdx<pConfig->nPrefix; iIdx++){
    int nByte = fts5IndexCharlenToBytelen(pTerm, nTerm, pConfig->aPrefix[iIdx]);
    if( nByte ){
      ret ^= fts5IndexEntryCksum(iRowid, iCol, iPos, iIdx+1, pTerm, nByte);
    }
  }

  return ret;
}

/*************************************************************************
**************************************************************************
** Below this point is the implementation of the fts5_decode() scalar
** function only.
*/

/*
................................................................................
      iDocid += iDelta;
      sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " id=%lld", iDocid);
    }
  }

  return iOff;
}










































/*
** The implementation of user-defined scalar function fts5_decode().
*/
static void fts5DecodeFunction(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args (always 2) */
................................................................................
  i64 iRowid;                     /* Rowid for record being decoded */
  int iSegid,iHeight,iPgno,bDlidx;/* Rowid components */
  const u8 *aBlob; int n;         /* Record to decode */
  u8 *a = 0;
  Fts5Buffer s;                   /* Build up text to return here */
  int rc = SQLITE_OK;             /* Return code */
  int nSpace = 0;


  assert( nArg==2 );

  memset(&s, 0, sizeof(Fts5Buffer));
  iRowid = sqlite3_value_int64(apVal[0]);

  /* Make a copy of the second argument (a blob) in aBlob[]. The aBlob[]
  ** copy is followed by FTS5_DATA_ZERO_PADDING 0x00 bytes, which prevents
  ** buffer overreads even if the record is corrupt.  */
  n = sqlite3_value_bytes(apVal[1]);
................................................................................
    }
  }else if( iSegid==0 ){
    if( iRowid==FTS5_AVERAGES_ROWID ){
      fts5DecodeAverages(&rc, &s, a, n);
    }else{
      fts5DecodeStructure(&rc, &s, a, n);
    }
















































  }else{
    Fts5Buffer term;              /* Current term read from page */
    int szLeaf;                   /* Offset of pgidx in a[] */
    int iPgidxOff;
    int iPgidxPrev = 0;           /* Previous value read from pgidx */
    int iTermOff = 0;
    int iRowidOff = 0;
................................................................................
** If successful, SQLITE_OK is returned. If an error occurs, some other
** SQLite error code is returned instead.
*/
static int sqlite3Fts5IndexInit(sqlite3 *db){
  int rc = sqlite3_create_function(
      db, "fts5_decode", 2, SQLITE_UTF8, 0, fts5DecodeFunction, 0, 0
  );








  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(
        db, "fts5_rowid", -1, SQLITE_UTF8, 0, fts5RowidFunction, 0, 0
    );
  }
  return rc;
}


/*
** 2014 Jun 09
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
................................................................................
#define FTS5_BI_ORDER_RANK   0x0020
#define FTS5_BI_ORDER_ROWID  0x0040
#define FTS5_BI_ORDER_DESC   0x0080

/*
** Values for Fts5Cursor.csrflags
*/

#define FTS5CSR_REQUIRE_CONTENT   0x01
#define FTS5CSR_REQUIRE_DOCSIZE   0x02
#define FTS5CSR_REQUIRE_INST      0x04
#define FTS5CSR_EOF               0x08
#define FTS5CSR_FREE_ZRANK        0x10
#define FTS5CSR_REQUIRE_RESEEK    0x20


#define BitFlagAllTest(x,y) (((x) & (y))==(y))
#define BitFlagTest(x,y)    (((x) & (y))!=0)


/*
** Macros to Set(), Clear() and Test() cursor flags.
................................................................................
  aColMap[1] = pConfig->nCol;
  aColMap[2] = pConfig->nCol+1;

  /* Set idxFlags flags for all WHERE clause terms that will be used. */
  for(i=0; i<pInfo->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pInfo->aConstraint[i];
    int j;
    for(j=0; j<(int)ArraySize(aConstraint); j++){
      struct Constraint *pC = &aConstraint[j];
      if( p->iColumn==aColMap[pC->iCol] && p->op & pC->op ){
        if( p->usable ){
          pC->iConsIndex = i;
          idxFlags |= pC->fts5op;
        }else if( j==0 ){
          /* As there exists an unusable MATCH constraint this is an 
................................................................................
    pInfo->estimatedCost = bHasMatch ? 750.0 : 750000.0;
  }else{
    pInfo->estimatedCost = bHasMatch ? 1000.0 : 1000000.0;
  }

  /* Assign argvIndex values to each constraint in use. */
  iNext = 1;
  for(i=0; i<(int)ArraySize(aConstraint); i++){
    struct Constraint *pC = &aConstraint[i];
    if( pC->iConsIndex>=0 ){
      pInfo->aConstraintUsage[pC->iConsIndex].argvIndex = iNext++;
      pInfo->aConstraintUsage[pC->iConsIndex].omit = (unsigned char)pC->omit;
    }
  }

................................................................................
** specific to the previous row stored by the cursor object.
*/
static void fts5CsrNewrow(Fts5Cursor *pCsr){
  CsrFlagSet(pCsr, 
      FTS5CSR_REQUIRE_CONTENT 
    | FTS5CSR_REQUIRE_DOCSIZE 
    | FTS5CSR_REQUIRE_INST 

  );
}

static void fts5FreeCursorComponents(Fts5Cursor *pCsr){
  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
  Fts5Auxdata *pData;
  Fts5Auxdata *pNext;
................................................................................
    int iOff = 0;
    rc = SQLITE_OK;

    pSorter->iRowid = sqlite3_column_int64(pSorter->pStmt, 0);
    nBlob = sqlite3_column_bytes(pSorter->pStmt, 1);
    aBlob = a = sqlite3_column_blob(pSorter->pStmt, 1);



    for(i=0; i<(pSorter->nIdx-1); i++){
      int iVal;
      a += fts5GetVarint32(a, iVal);
      iOff += iVal;
      pSorter->aIdx[i] = iOff;
    }
    pSorter->aIdx[i] = &aBlob[nBlob] - a;

    pSorter->aPoslist = a;


    fts5CsrNewrow(pCsr);
  }

  return rc;
}


................................................................................
  assert( *pbSkip==0 );
  if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_RESEEK) ){
    Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
    int bDesc = pCsr->bDesc;
    i64 iRowid = sqlite3Fts5ExprRowid(pCsr->pExpr);

    rc = sqlite3Fts5ExprFirst(pCsr->pExpr, pTab->pIndex, iRowid, bDesc);
    if( rc==SQLITE_OK && iRowid!=sqlite3Fts5ExprRowid(pCsr->pExpr) ){
      *pbSkip = 1;
    }

    CsrFlagClear(pCsr, FTS5CSR_REQUIRE_RESEEK);
    fts5CsrNewrow(pCsr);
    if( sqlite3Fts5ExprEof(pCsr->pExpr) ){
      CsrFlagSet(pCsr, FTS5CSR_EOF);

    }
  }
  return rc;
}


/*
................................................................................
**
** Return SQLITE_OK if nothing goes wrong.  SQLITE_OK is returned
** even if we reach end-of-file.  The fts5EofMethod() will be called
** subsequently to determine whether or not an EOF was hit.
*/
static int fts5NextMethod(sqlite3_vtab_cursor *pCursor){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;
  int rc = SQLITE_OK;

  assert( (pCsr->ePlan<3)==
          (pCsr->ePlan==FTS5_PLAN_MATCH || pCsr->ePlan==FTS5_PLAN_SOURCE) 
  );


  if( pCsr->ePlan<3 ){
    int bSkip = 0;
    if( (rc = fts5CursorReseek(pCsr, &bSkip)) || bSkip ) return rc;
    rc = sqlite3Fts5ExprNext(pCsr->pExpr, pCsr->iLastRowid);
    if( sqlite3Fts5ExprEof(pCsr->pExpr) ){
      CsrFlagSet(pCsr, FTS5CSR_EOF);
    }
    fts5CsrNewrow(pCsr);
  }else{
    switch( pCsr->ePlan ){
      case FTS5_PLAN_SPECIAL: {
        CsrFlagSet(pCsr, FTS5CSR_EOF);

        break;
      }
  
      case FTS5_PLAN_SORTED_MATCH: {
        rc = fts5SorterNext(pCsr);
        break;
      }
................................................................................
    }
  }
  
  return rc;
}


static sqlite3_stmt *fts5PrepareStatement(
  int *pRc,
  Fts5Config *pConfig, 
  const char *zFmt,
  ...
){
  sqlite3_stmt *pRet = 0;


  va_list ap;
  va_start(ap, zFmt);

  if( *pRc==SQLITE_OK ){
    int rc;
    char *zSql = sqlite3_vmprintf(zFmt, ap);
    if( zSql==0 ){
      rc = SQLITE_NOMEM; 
    }else{
      rc = sqlite3_prepare_v2(pConfig->db, zSql, -1, &pRet, 0);
      if( rc!=SQLITE_OK ){
        *pConfig->pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(pConfig->db));
      }
      sqlite3_free(zSql);
    }
    *pRc = rc;
  }

  va_end(ap);

  return pRet;
} 

static int fts5CursorFirstSorted(Fts5Table *pTab, Fts5Cursor *pCsr, int bDesc){
  Fts5Config *pConfig = pTab->pConfig;
  Fts5Sorter *pSorter;
  int nPhrase;
  int nByte;
  int rc = SQLITE_OK;
  const char *zRank = pCsr->zRank;
  const char *zRankArgs = pCsr->zRankArgs;
  
  nPhrase = sqlite3Fts5ExprPhraseCount(pCsr->pExpr);
  nByte = sizeof(Fts5Sorter) + sizeof(int) * (nPhrase-1);
  pSorter = (Fts5Sorter*)sqlite3_malloc(nByte);
  if( pSorter==0 ) return SQLITE_NOMEM;
................................................................................
  /* TODO: It would be better to have some system for reusing statement
  ** handles here, rather than preparing a new one for each query. But that
  ** is not possible as SQLite reference counts the virtual table objects.
  ** And since the statement required here reads from this very virtual 
  ** table, saving it creates a circular reference.
  **
  ** If SQLite a built-in statement cache, this wouldn't be a problem. */
  pSorter->pStmt = fts5PrepareStatement(&rc, pConfig,
      "SELECT rowid, rank FROM %Q.%Q ORDER BY %s(%s%s%s) %s",
      pConfig->zDb, pConfig->zName, zRank, pConfig->zName,
      (zRankArgs ? ", " : ""),
      (zRankArgs ? zRankArgs : ""),
      bDesc ? "DESC" : "ASC"
  );

................................................................................
**   1. Full-text search using a MATCH operator.
**   2. A by-rowid lookup.
**   3. A full-table scan.
*/
static int fts5FilterMethod(
  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
  int idxNum,                     /* Strategy index */
  const char *idxStr,             /* Unused */
  int nVal,                       /* Number of elements in apVal */
  sqlite3_value **apVal           /* Arguments for the indexing scheme */
){
  Fts5Table *pTab = (Fts5Table*)(pCursor->pVtab);
  Fts5Config *pConfig = pTab->pConfig;
  Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;
  int rc = SQLITE_OK;             /* Error code */
................................................................................
  int bOrderByRank;               /* True if ORDER BY rank */
  sqlite3_value *pMatch = 0;      /* <tbl> MATCH ? expression (or NULL) */
  sqlite3_value *pRank = 0;       /* rank MATCH ? expression (or NULL) */
  sqlite3_value *pRowidEq = 0;    /* rowid = ? expression (or NULL) */
  sqlite3_value *pRowidLe = 0;    /* rowid <= ? expression (or NULL) */
  sqlite3_value *pRowidGe = 0;    /* rowid >= ? expression (or NULL) */
  char **pzErrmsg = pConfig->pzErrmsg;




  if( pCsr->ePlan ){
    fts5FreeCursorComponents(pCsr);
    memset(&pCsr->ePlan, 0, sizeof(Fts5Cursor) - ((u8*)&pCsr->ePlan-(u8*)pCsr));
  }

  assert( pCsr->pStmt==0 );
................................................................................
    assert( pRowidEq==0 && pRowidLe==0 && pRowidGe==0 && pRank==0 );
    assert( nVal==0 && pMatch==0 && bOrderByRank==0 && bDesc==0 );
    assert( pCsr->iLastRowid==LARGEST_INT64 );
    assert( pCsr->iFirstRowid==SMALLEST_INT64 );
    pCsr->ePlan = FTS5_PLAN_SOURCE;
    pCsr->pExpr = pTab->pSortCsr->pExpr;
    rc = fts5CursorFirst(pTab, pCsr, bDesc);

  }else if( pMatch ){
    const char *zExpr = (const char*)sqlite3_value_text(apVal[0]);
    if( zExpr==0 ) zExpr = "";

    rc = fts5CursorParseRank(pConfig, pCsr, pRank);
    if( rc==SQLITE_OK ){
      if( zExpr[0]=='*' ){
................................................................................
    }
  }
  return rc;
}

static int fts5SpecialDelete(
  Fts5Table *pTab, 
  sqlite3_value **apVal, 
  sqlite3_int64 *piRowid
){
  int rc = SQLITE_OK;
  int eType1 = sqlite3_value_type(apVal[1]);
  if( eType1==SQLITE_INTEGER ){
    sqlite3_int64 iDel = sqlite3_value_int64(apVal[1]);
    rc = sqlite3Fts5StorageSpecialDelete(pTab->pStorage, iDel, &apVal[2]);
  }
  return rc;
}

static void fts5StorageInsert(
  int *pRc, 
  Fts5Table *pTab, 
................................................................................
   && sqlite3_value_type(apVal[2+pConfig->nCol])!=SQLITE_NULL 
  ){
    /* A "special" INSERT op. These are handled separately. */
    const char *z = (const char*)sqlite3_value_text(apVal[2+pConfig->nCol]);
    if( pConfig->eContent!=FTS5_CONTENT_NORMAL 
      && 0==sqlite3_stricmp("delete", z) 
    ){
      rc = fts5SpecialDelete(pTab, apVal, pRowid);
    }else{
      rc = fts5SpecialInsert(pTab, z, apVal[2 + pConfig->nCol + 1]);
    }
  }else{
    /* A regular INSERT, UPDATE or DELETE statement. The trick here is that
    ** any conflict on the rowid value must be detected before any 
    ** modifications are made to the database file. There are 4 cases:
................................................................................
      );
      rc = SQLITE_ERROR;
    }

    /* Case 1: DELETE */
    else if( nArg==1 ){
      i64 iDel = sqlite3_value_int64(apVal[0]);  /* Rowid to delete */
      rc = sqlite3Fts5StorageDelete(pTab->pStorage, iDel);
    }

    /* Case 2: INSERT */
    else if( eType0!=SQLITE_INTEGER ){     
      /* If this is a REPLACE, first remove the current entry (if any) */
      if( eConflict==SQLITE_REPLACE 
       && sqlite3_value_type(apVal[1])==SQLITE_INTEGER 
      ){
        i64 iNew = sqlite3_value_int64(apVal[1]);  /* Rowid to delete */
        rc = sqlite3Fts5StorageDelete(pTab->pStorage, iNew);
      }
      fts5StorageInsert(&rc, pTab, apVal, pRowid);
    }

    /* Case 2: UPDATE */
    else{
      i64 iOld = sqlite3_value_int64(apVal[0]);  /* Old rowid */
      i64 iNew = sqlite3_value_int64(apVal[1]);  /* New rowid */
      if( iOld!=iNew ){
        if( eConflict==SQLITE_REPLACE ){
          rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld);
          if( rc==SQLITE_OK ){
            rc = sqlite3Fts5StorageDelete(pTab->pStorage, iNew);
          }
          fts5StorageInsert(&rc, pTab, apVal, pRowid);
        }else{
          rc = sqlite3Fts5StorageContentInsert(pTab->pStorage, apVal, pRowid);
          if( rc==SQLITE_OK ){
            rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld);
          }
          if( rc==SQLITE_OK ){
            rc = sqlite3Fts5StorageIndexInsert(pTab->pStorage, apVal, *pRowid);
          }
        }
      }else{
        rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld);
        fts5StorageInsert(&rc, pTab, apVal, pRowid);
      }
    }
  }

  pTab->pConfig->pzErrmsg = 0;
  return rc;
................................................................................
  return rc;
}

/*
** Implementation of xBegin() method. 
*/
static int fts5BeginMethod(sqlite3_vtab *pVtab){

  fts5CheckTransactionState((Fts5Table*)pVtab, FTS5_BEGIN, 0);
  return SQLITE_OK;
}

/*
** Implementation of xCommit() method. This is a no-op. The contents of
** the pending-terms hash-table have already been flushed into the database
** by fts5SyncMethod().
*/
static int fts5CommitMethod(sqlite3_vtab *pVtab){

  fts5CheckTransactionState((Fts5Table*)pVtab, FTS5_COMMIT, 0);
  return SQLITE_OK;
}

/*
** Implementation of xRollback(). Discard the contents of the pending-terms
** hash-table. Any changes made to the database are reverted by SQLite.
................................................................................
static int fts5RollbackMethod(sqlite3_vtab *pVtab){
  int rc;
  Fts5Table *pTab = (Fts5Table*)pVtab;
  fts5CheckTransactionState(pTab, FTS5_ROLLBACK, 0);
  rc = sqlite3Fts5StorageRollback(pTab->pStorage);
  return rc;
}



static void *fts5ApiUserData(Fts5Context *pCtx){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  return pCsr->pAux->pUserData;
}

static int fts5ApiColumnCount(Fts5Context *pCtx){
................................................................................
}

static int fts5ApiPhraseSize(Fts5Context *pCtx, int iPhrase){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  return sqlite3Fts5ExprPhraseSize(pCsr->pExpr, iPhrase);
}






















static int fts5CsrPoslist(Fts5Cursor *pCsr, int iPhrase, const u8 **pa){



  int n;























  if( pCsr->pSorter ){







    Fts5Sorter *pSorter = pCsr->pSorter;
    int i1 = (iPhrase==0 ? 0 : pSorter->aIdx[iPhrase-1]);
    n = pSorter->aIdx[iPhrase] - i1;
    *pa = &pSorter->aPoslist[i1];
  }else{
    n = sqlite3Fts5ExprPoslist(pCsr->pExpr, iPhrase, pa);
  }

  return n;
}

/*
** Ensure that the Fts5Cursor.nInstCount and aInst[] variables are populated
** correctly for the current view. Return SQLITE_OK if successful, or an
** SQLite error code otherwise.
*/
................................................................................
  aIter = pCsr->aInstIter;

  if( aIter ){
    int nInst = 0;                /* Number instances seen so far */
    int i;

    /* Initialize all iterators */
    for(i=0; i<nIter; i++){
      const u8 *a;

      int n = fts5CsrPoslist(pCsr, i, &a);

      sqlite3Fts5PoslistReaderInit(a, n, &aIter[i]);
    }



    while( 1 ){
      int *aInst;
      int iBest = -1;
      for(i=0; i<nIter; i++){
        if( (aIter[i].bEof==0) 
         && (iBest<0 || aIter[i].iPos<aIter[iBest].iPos) 
        ){
          iBest = i;
        }
      }
      if( iBest<0 ) break;

      nInst++;
      if( nInst>=pCsr->nInstAlloc ){
        pCsr->nInstAlloc = pCsr->nInstAlloc ? pCsr->nInstAlloc*2 : 32;
        aInst = (int*)sqlite3_realloc(
            pCsr->aInst, pCsr->nInstAlloc*sizeof(int)*3
        );
        if( aInst ){
          pCsr->aInst = aInst;
        }else{
          rc = SQLITE_NOMEM;
          break;
        }
      }

      aInst = &pCsr->aInst[3 * (nInst-1)];
      aInst[0] = iBest;
      aInst[1] = FTS5_POS2COLUMN(aIter[iBest].iPos);
      aInst[2] = FTS5_POS2OFFSET(aIter[iBest].iPos);
      sqlite3Fts5PoslistReaderNext(&aIter[iBest]);

    }

    pCsr->nInstCount = nInst;
    CsrFlagClear(pCsr, FTS5CSR_REQUIRE_INST);
  }
  return rc;
}
................................................................................
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  int rc = SQLITE_OK;
  if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_INST)==0 
   || SQLITE_OK==(rc = fts5CacheInstArray(pCsr)) 
  ){
    if( iIdx<0 || iIdx>=pCsr->nInstCount ){
      rc = SQLITE_RANGE;






    }else{
      *piPhrase = pCsr->aInst[iIdx*3];
      *piCol = pCsr->aInst[iIdx*3 + 1];
      *piOff = pCsr->aInst[iIdx*3 + 2];
    }
  }
  return rc;
}

static sqlite3_int64 fts5ApiRowid(Fts5Context *pCtx){
  return fts5CursorRowid((Fts5Cursor*)pCtx);
}

static int fts5ApiColumnText(
  Fts5Context *pCtx, 
  int iCol, 
  const char **pz, 
  int *pn
){
  int rc = SQLITE_OK;
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  if( fts5IsContentless((Fts5Table*)(pCsr->base.pVtab)) ){
    *pz = 0;
    *pn = 0;
  }else{
    rc = fts5SeekCursor(pCsr, 0);
    if( rc==SQLITE_OK ){
      *pz = (const char*)sqlite3_column_text(pCsr->pStmt, iCol+1);
      *pn = sqlite3_column_bytes(pCsr->pStmt, iCol+1);
    }
  }
  return rc;
}

static int fts5ColumnSizeCb(
  void *pContext,                 /* Pointer to int */
  int tflags,
  const char *pToken,             /* Buffer containing token */
  int nToken,                     /* Size of token in bytes */
  int iStart,                     /* Start offset of token */
  int iEnd                        /* End offset of token */
){
  int *pCnt = (int*)pContext;


  if( (tflags & FTS5_TOKEN_COLOCATED)==0 ){
    (*pCnt)++;
  }
  return SQLITE_OK;
}

static int fts5ApiColumnSize(Fts5Context *pCtx, int iCol, int *pnToken){
................................................................................
    }
  }

  return pRet;
}

static void fts5ApiPhraseNext(
  Fts5Context *pCtx, 
  Fts5PhraseIter *pIter, 
  int *piCol, int *piOff
){

  if( pIter->a>=pIter->b ){
    *piCol = -1;
    *piOff = -1;
  }else{
    int iVal;
    pIter->a += fts5GetVarint32(pIter->a, iVal);
    if( iVal==1 ){
................................................................................
      *piOff = 0;
      pIter->a += fts5GetVarint32(pIter->a, iVal);
    }
    *piOff += (iVal-2);
  }
}

static void fts5ApiPhraseFirst(
  Fts5Context *pCtx, 
  int iPhrase, 
  Fts5PhraseIter *pIter, 
  int *piCol, int *piOff
){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  int n = fts5CsrPoslist(pCsr, iPhrase, &pIter->a);

  pIter->b = &pIter->a[n];
  *piCol = 0;
  *piOff = 0;
  fts5ApiPhraseNext(pCtx, pIter, piCol, piOff);
}













































































static int fts5ApiQueryPhrase(Fts5Context*, int, void*, 
    int(*)(const Fts5ExtensionApi*, Fts5Context*, void*)
);

static const Fts5ExtensionApi sFts5Api = {
  2,                            /* iVersion */
................................................................................
  fts5ApiColumnText,
  fts5ApiColumnSize,
  fts5ApiQueryPhrase,
  fts5ApiSetAuxdata,
  fts5ApiGetAuxdata,
  fts5ApiPhraseFirst,
  fts5ApiPhraseNext,


};


/*
** Implementation of API function xQueryPhrase().
*/
static int fts5ApiQueryPhrase(
  Fts5Context *pCtx, 
  int iPhrase, 
................................................................................
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
  int rc;
  Fts5Cursor *pNew = 0;

  rc = fts5OpenMethod(pCsr->base.pVtab, (sqlite3_vtab_cursor**)&pNew);
  if( rc==SQLITE_OK ){
    Fts5Config *pConf = pTab->pConfig;
    pNew->ePlan = FTS5_PLAN_MATCH;
    pNew->iFirstRowid = SMALLEST_INT64;
    pNew->iLastRowid = LARGEST_INT64;
    pNew->base.pVtab = (sqlite3_vtab*)pTab;
    rc = sqlite3Fts5ExprClonePhrase(pConf, pCsr->pExpr, iPhrase, &pNew->pExpr);
  }

  if( rc==SQLITE_OK ){
    for(rc = fts5CursorFirst(pTab, pNew, 0);
        rc==SQLITE_OK && CsrFlagTest(pNew, FTS5CSR_EOF)==0;
        rc = fts5NextMethod((sqlite3_vtab_cursor*)pNew)
    ){
................................................................................
static int fts5PoslistBlob(sqlite3_context *pCtx, Fts5Cursor *pCsr){
  int i;
  int rc = SQLITE_OK;
  int nPhrase = sqlite3Fts5ExprPhraseCount(pCsr->pExpr);
  Fts5Buffer val;

  memset(&val, 0, sizeof(Fts5Buffer));



  /* Append the varints */
  for(i=0; i<(nPhrase-1); i++){
    const u8 *dummy;
    int nByte = sqlite3Fts5ExprPoslist(pCsr->pExpr, i, &dummy);
    sqlite3Fts5BufferAppendVarint(&rc, &val, nByte);
  }

  /* Append the position lists */
  for(i=0; i<nPhrase; i++){
    const u8 *pPoslist;
    int nPoslist;
    nPoslist = sqlite3Fts5ExprPoslist(pCsr->pExpr, i, &pPoslist);
    sqlite3Fts5BufferAppendBlob(&rc, &val, nPoslist, pPoslist);
























  }

  sqlite3_result_blob(pCtx, val.p, val.n, sqlite3_free);
  return rc;
}

/* 
................................................................................

/*
** This routine implements the xFindFunction method for the FTS3
** virtual table.
*/
static int fts5FindFunctionMethod(
  sqlite3_vtab *pVtab,            /* Virtual table handle */
  int nArg,                       /* Number of SQL function arguments */
  const char *zName,              /* Name of SQL function */
  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), /* OUT: Result */
  void **ppArg                    /* OUT: User data for *pxFunc */
){
  Fts5Table *pTab = (Fts5Table*)pVtab;
  Fts5Auxiliary *pAux;


  pAux = fts5FindAuxiliary(pTab, zName);
  if( pAux ){
    *pxFunc = fts5ApiCallback;
    *ppArg = (void*)pAux;
    return 1;
  }

................................................................................
/*
** The xSavepoint() method.
**
** Flush the contents of the pending-terms table to disk.
*/
static int fts5SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){
  Fts5Table *pTab = (Fts5Table*)pVtab;

  fts5CheckTransactionState(pTab, FTS5_SAVEPOINT, iSavepoint);
  fts5TripCursors(pTab);
  return sqlite3Fts5StorageSync(pTab->pStorage, 0);
}

/*
** The xRelease() method.
**
** This is a no-op.
*/
static int fts5ReleaseMethod(sqlite3_vtab *pVtab, int iSavepoint){
  Fts5Table *pTab = (Fts5Table*)pVtab;

  fts5CheckTransactionState(pTab, FTS5_RELEASE, iSavepoint);
  fts5TripCursors(pTab);
  return sqlite3Fts5StorageSync(pTab->pStorage, 0);
}

/*
** The xRollbackTo() method.
**
** Discard the contents of the pending terms table.
*/
static int fts5RollbackToMethod(sqlite3_vtab *pVtab, int iSavepoint){
  Fts5Table *pTab = (Fts5Table*)pVtab;

  fts5CheckTransactionState(pTab, FTS5_ROLLBACKTO, iSavepoint);
  fts5TripCursors(pTab);
  return sqlite3Fts5StorageRollback(pTab->pStorage);
}

/*
** Register a new auxiliary function with global context pGlobal.
................................................................................

  sqlite3_free(pGlobal);
}

static void fts5Fts5Func(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apVal           /* Function arguments */
){
  Fts5Global *pGlobal = (Fts5Global*)sqlite3_user_data(pCtx);
  char buf[8];

  assert( nArg==0 );
  assert( sizeof(buf)>=sizeof(pGlobal) );
  memcpy(buf, (void*)&pGlobal, sizeof(pGlobal));
  sqlite3_result_blob(pCtx, buf, sizeof(pGlobal), SQLITE_TRANSIENT);
}

/*
** Implementation of fts5_source_id() function.
*/
static void fts5SourceIdFunc(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apVal           /* Function arguments */
){
  assert( nArg==0 );
  sqlite3_result_text(pCtx, "fts5: 2016-01-20 15:27:19 17efb4209f97fb4971656086b138599a91a75ff9", -1, SQLITE_TRANSIENT);

}

static int fts5Init(sqlite3 *db){
  static const sqlite3_module fts5Mod = {
    /* iVersion      */ 2,
    /* xCreate       */ fts5CreateMethod,
    /* xConnect      */ fts5ConnectMethod,
................................................................................
*/
static int sqlite3Fts5StorageClose(Fts5Storage *p){
  int rc = SQLITE_OK;
  if( p ){
    int i;

    /* Finalize all SQL statements */
    for(i=0; i<(int)ArraySize(p->aStmt); i++){
      sqlite3_finalize(p->aStmt[i]);
    }

    sqlite3_free(p);
  }
  return rc;
}
................................................................................
** Tokenization callback used when inserting tokens into the FTS index.
*/
static int fts5StorageInsertCallback(
  void *pContext,                 /* Pointer to Fts5InsertCtx object */
  int tflags,
  const char *pToken,             /* Buffer containing token */
  int nToken,                     /* Size of token in bytes */
  int iStart,                     /* Start offset of token */
  int iEnd                        /* End offset of token */
){
  Fts5InsertCtx *pCtx = (Fts5InsertCtx*)pContext;
  Fts5Index *pIdx = pCtx->pStorage->pIndex;

  if( (tflags & FTS5_TOKEN_COLOCATED)==0 || pCtx->szCol==0 ){
    pCtx->szCol++;
  }
  return sqlite3Fts5IndexWrite(pIdx, pCtx->iCol, pCtx->szCol-1, pToken, nToken);
}

/*
** If a row with rowid iDel is present in the %_content table, add the
** delete-markers to the FTS index necessary to delete it. Do not actually
** remove the %_content row at this time though.
*/
static int fts5StorageDeleteFromIndex(Fts5Storage *p, i64 iDel){




  Fts5Config *pConfig = p->pConfig;
  sqlite3_stmt *pSeek;            /* SELECT to read row iDel from %_data */
  int rc;                         /* Return code */





  rc = fts5StorageGetStmt(p, FTS5_STMT_LOOKUP, &pSeek, 0);
  if( rc==SQLITE_OK ){
    int rc2;
    sqlite3_bind_int64(pSeek, 1, iDel);
    if( sqlite3_step(pSeek)==SQLITE_ROW ){
      int iCol;
      Fts5InsertCtx ctx;




      ctx.pStorage = p;
      ctx.iCol = -1;
      rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 1, iDel);
      for(iCol=1; rc==SQLITE_OK && iCol<=pConfig->nCol; iCol++){
        if( pConfig->abUnindexed[iCol-1] ) continue;
        ctx.szCol = 0;
        rc = sqlite3Fts5Tokenize(pConfig, 
            FTS5_TOKENIZE_DOCUMENT,



            (const char*)sqlite3_column_text(pSeek, iCol),
            sqlite3_column_bytes(pSeek, iCol),
            (void*)&ctx,






            fts5StorageInsertCallback
        );
        p->aTotalSize[iCol-1] -= (i64)ctx.szCol;
      }

      p->nTotalRow--;
    }
    rc2 = sqlite3_reset(pSeek);
    if( rc==SQLITE_OK ) rc = rc2;
  }

  return rc;
}


/*
** Insert a record into the %_docsize table. Specifically, do:
**
................................................................................

  return rc;
}

/*
** Remove a row from the FTS table.
*/
static int sqlite3Fts5StorageDelete(Fts5Storage *p, i64 iDel){
  Fts5Config *pConfig = p->pConfig;
  int rc;
  sqlite3_stmt *pDel = 0;


  rc = fts5StorageLoadTotals(p, 1);

  /* Delete the index records */
  if( rc==SQLITE_OK ){
    rc = fts5StorageDeleteFromIndex(p, iDel);
  }

  /* Delete the %_docsize record */
  if( rc==SQLITE_OK && pConfig->bColumnsize ){
    rc = fts5StorageGetStmt(p, FTS5_STMT_DELETE_DOCSIZE, &pDel, 0);
    if( rc==SQLITE_OK ){
      sqlite3_bind_int64(pDel, 1, iDel);
................................................................................
  }

  /* Delete the %_content record */
  if( pConfig->eContent==FTS5_CONTENT_NORMAL ){
    if( rc==SQLITE_OK ){
      rc = fts5StorageGetStmt(p, FTS5_STMT_DELETE_CONTENT, &pDel, 0);
    }
    if( rc==SQLITE_OK ){
      sqlite3_bind_int64(pDel, 1, iDel);
      sqlite3_step(pDel);
      rc = sqlite3_reset(pDel);
    }
  }

  /* Write the averages record */
  if( rc==SQLITE_OK ){
    rc = fts5StorageSaveTotals(p);
  }

  return rc;
}

static int sqlite3Fts5StorageSpecialDelete(
  Fts5Storage *p, 
  i64 iDel, 
  sqlite3_value **apVal
){
  Fts5Config *pConfig = p->pConfig;
  int rc;
  sqlite3_stmt *pDel = 0;

  assert( pConfig->eContent!=FTS5_CONTENT_NORMAL );
  rc = fts5StorageLoadTotals(p, 1);

  /* Delete the index records */
  if( rc==SQLITE_OK ){
    int iCol;
    Fts5InsertCtx ctx;
    ctx.pStorage = p;
    ctx.iCol = -1;

    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 1, iDel);
    for(iCol=0; rc==SQLITE_OK && iCol<pConfig->nCol; iCol++){
      if( pConfig->abUnindexed[iCol] ) continue;
      ctx.szCol = 0;
      rc = sqlite3Fts5Tokenize(pConfig, 
        FTS5_TOKENIZE_DOCUMENT,
        (const char*)sqlite3_value_text(apVal[iCol]),
        sqlite3_value_bytes(apVal[iCol]),
        (void*)&ctx,
        fts5StorageInsertCallback
      );
      p->aTotalSize[iCol] -= (i64)ctx.szCol;
    }
    p->nTotalRow--;
  }

  /* Delete the %_docsize record */
  if( pConfig->bColumnsize ){
    if( rc==SQLITE_OK ){
      rc = fts5StorageGetStmt(p, FTS5_STMT_DELETE_DOCSIZE, &pDel, 0);
    }
    if( rc==SQLITE_OK ){
      sqlite3_bind_int64(pDel, 1, iDel);
      sqlite3_step(pDel);
      rc = sqlite3_reset(pDel);
    }
  }

................................................................................
*/
typedef struct Fts5IntegrityCtx Fts5IntegrityCtx;
struct Fts5IntegrityCtx {
  i64 iRowid;
  int iCol;
  int szCol;
  u64 cksum;

  Fts5Config *pConfig;
};


/*
** Tokenization callback used by integrity check.
*/
static int fts5StorageIntegrityCallback(
  void *pContext,                 /* Pointer to Fts5InsertCtx object */
  int tflags,
  const char *pToken,             /* Buffer containing token */
  int nToken,                     /* Size of token in bytes */
  int iStart,                     /* Start offset of token */
  int iEnd                        /* End offset of token */
){
  Fts5IntegrityCtx *pCtx = (Fts5IntegrityCtx*)pContext;









  if( (tflags & FTS5_TOKEN_COLOCATED)==0 || pCtx->szCol==0 ){
    pCtx->szCol++;
  }





















  pCtx->cksum ^= sqlite3Fts5IndexCksum(
      pCtx->pConfig, pCtx->iRowid, pCtx->iCol, pCtx->szCol-1, pToken, nToken

  );















  return SQLITE_OK;
}

/*
** Check that the contents of the FTS index match that of the %_content
** table. Return SQLITE_OK if they do, or SQLITE_CORRUPT if not. Return
** some other SQLite error code if an error occurs while attempting to
** determine this.
................................................................................
    int rc2;
    while( SQLITE_ROW==sqlite3_step(pScan) ){
      int i;
      ctx.iRowid = sqlite3_column_int64(pScan, 0);
      ctx.szCol = 0;
      if( pConfig->bColumnsize ){
        rc = sqlite3Fts5StorageDocsize(p, ctx.iRowid, aColSize);



      }
      for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
        if( pConfig->abUnindexed[i] ) continue;
        ctx.iCol = i;
        ctx.szCol = 0;




        rc = sqlite3Fts5Tokenize(pConfig, 
            FTS5_TOKENIZE_DOCUMENT,
            (const char*)sqlite3_column_text(pScan, i+1),
            sqlite3_column_bytes(pScan, i+1),
            (void*)&ctx,
            fts5StorageIntegrityCallback
        );

        if( pConfig->bColumnsize && ctx.szCol!=aColSize[i] ){
          rc = FTS5_CORRUPT;
        }
        aTotalSize[i] += ctx.szCol;



      }




      if( rc!=SQLITE_OK ) break;
    }
    rc2 = sqlite3_reset(pScan);
    if( rc==SQLITE_OK ) rc = rc2;
  }

  /* Test that the "totals" (sometimes called "averages") record looks Ok */
................................................................................
  sqlite3_free(p);
}

/*
** Create an "ascii" tokenizer.
*/
static int fts5AsciiCreate(
  void *pCtx, 
  const char **azArg, int nArg,
  Fts5Tokenizer **ppOut
){
  int rc = SQLITE_OK;
  AsciiTokenizer *p = 0;

  if( nArg%2 ){
    rc = SQLITE_ERROR;
  }else{
    p = sqlite3_malloc(sizeof(AsciiTokenizer));
    if( p==0 ){
      rc = SQLITE_NOMEM;
    }else{
................................................................................

/*
** Tokenize some text using the ascii tokenizer.
*/
static int fts5AsciiTokenize(
  Fts5Tokenizer *pTokenizer,
  void *pCtx,
  int flags,
  const char *pText, int nText,
  int (*xToken)(void*, int, const char*, int nToken, int iStart, int iEnd)
){
  AsciiTokenizer *p = (AsciiTokenizer*)pTokenizer;
  int rc = SQLITE_OK;
  int ie;
  int is = 0;

  char aFold[64];
  int nFold = sizeof(aFold);
  char *pFold = aFold;
  unsigned char *a = p->aTokenChar;



  while( is<nText && rc==SQLITE_OK ){
    int nByte;

    /* Skip any leading divider characters. */
    while( is<nText && ((pText[is]&0x80)==0 && a[(int)pText[is]]==0) ){
      is++;
................................................................................
  return;
}

/*
** Create a "unicode61" tokenizer.
*/
static int fts5UnicodeCreate(
  void *pCtx, 
  const char **azArg, int nArg,
  Fts5Tokenizer **ppOut
){
  int rc = SQLITE_OK;             /* Return code */
  Unicode61Tokenizer *p = 0;      /* New tokenizer object */ 



  if( nArg%2 ){
    rc = SQLITE_ERROR;
  }else{
    p = (Unicode61Tokenizer*)sqlite3_malloc(sizeof(Unicode61Tokenizer));
    if( p ){
      int i;
................................................................................
  assert( (sqlite3Fts5UnicodeIsalnum(iCode) & 0xFFFFFFFE)==0 );
  return sqlite3Fts5UnicodeIsalnum(iCode) ^ fts5UnicodeIsException(p, iCode);
}

static int fts5UnicodeTokenize(
  Fts5Tokenizer *pTokenizer,
  void *pCtx,
  int flags,
  const char *pText, int nText,
  int (*xToken)(void*, int, const char*, int nToken, int iStart, int iEnd)
){
  Unicode61Tokenizer *p = (Unicode61Tokenizer*)pTokenizer;
  int rc = SQLITE_OK;
  unsigned char *a = p->aTokenChar;

................................................................................
  unsigned char *zTerm = (unsigned char*)&pText[nText];
  unsigned char *zCsr = (unsigned char *)pText;

  /* Output buffer */
  char *aFold = p->aFold;
  int nFold = p->nFold;
  const char *pEnd = &aFold[nFold-6];



  /* Each iteration of this loop gobbles up a contiguous run of separators,
  ** then the next token.  */
  while( rc==SQLITE_OK ){
    int iCode;                    /* non-ASCII codepoint read from input */
    char *zOut = aFold;
    int is;
................................................................................
    { "ascii",     {fts5AsciiCreate, fts5AsciiDelete, fts5AsciiTokenize }},
    { "porter",    {fts5PorterCreate, fts5PorterDelete, fts5PorterTokenize }},
  };
  
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* To iterate through builtin functions */

  for(i=0; rc==SQLITE_OK && i<(int)ArraySize(aBuiltin); i++){
    rc = pApi->xCreateTokenizer(pApi,
        aBuiltin[i].zName,
        (void*)pApi,
        &aBuiltin[i].x,
        0
    );
  }
................................................................................
    0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401, 0x38008060,
    0x380400F0,
  };
  static const unsigned int aAscii[4] = {
    0xFFFFFFFF, 0xFC00FFFF, 0xF8000001, 0xF8000001,
  };

  if( c<128 ){
    return ( (aAscii[c >> 5] & (1 << (c & 0x001F)))==0 );
  }else if( c<(1<<22) ){
    unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;
    int iRes = 0;
    int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
    int iLo = 0;
    while( iHi>=iLo ){
      int iTest = (iHi + iLo) / 2;
      if( key >= aEntry[iTest] ){
................................................................................
    return 2;
  }
  return fts5PutVarint64(p,v);
}


static int sqlite3Fts5GetVarintLen(u32 iVal){

  if( iVal<(1 << 7 ) ) return 1;


  if( iVal<(1 << 14) ) return 2;
  if( iVal<(1 << 21) ) return 3;
  if( iVal<(1 << 28) ) return 4;
  return 5;
}


................................................................................
    const char *zType = bDb ? argv[5] : argv[4];
    int nDb = (int)strlen(zDb)+1; 
    int nTab = (int)strlen(zTab)+1;
    int eType = 0;
    
    rc = fts5VocabTableType(zType, pzErr, &eType);
    if( rc==SQLITE_OK ){
      assert( eType>=0 && eType<sizeof(azSchema)/sizeof(azSchema[0]) );
      rc = sqlite3_declare_vtab(db, azSchema[eType]);
    }

    nByte = sizeof(Fts5VocabTable) + nDb + nTab;
    pRet = sqlite3Fts5MallocZero(&rc, nByte);
    if( pRet ){
      pRet->pGlobal = (Fts5Global*)pAux;
................................................................................
  return fts5VocabInitVtab(db, pAux, argc, argv, ppVtab, pzErr);
}

/* 
** Implementation of the xBestIndex method.
*/
static int fts5VocabBestIndexMethod(
  sqlite3_vtab *pVTab, 
  sqlite3_index_info *pInfo
){
  int i;
  int iTermEq = -1;
  int iTermGe = -1;
  int iTermLe = -1;
  int idxNum = 0;
  int nArg = 0;



  for(i=0; i<pInfo->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pInfo->aConstraint[i];
    if( p->usable==0 ) continue;
    if( p->iColumn==0 ){          /* term column */
      if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ) iTermEq = i;
      if( p->op==SQLITE_INDEX_CONSTRAINT_LE ) iTermLe = i;
................................................................................
  int rc = SQLITE_OK;
  int nCol = pCsr->pConfig->nCol;

  pCsr->rowid++;

  if( pTab->eType==FTS5_VOCAB_COL ){
    for(pCsr->iCol++; pCsr->iCol<nCol; pCsr->iCol++){
      if( pCsr->aCnt[pCsr->iCol] ) break;
    }
  }

  if( pTab->eType==FTS5_VOCAB_ROW || pCsr->iCol>=nCol ){
    if( sqlite3Fts5IterEof(pCsr->pIter) ){
      pCsr->bEof = 1;
    }else{
................................................................................
      sqlite3Fts5BufferSet(&rc, &pCsr->term, nTerm, (const u8*)zTerm);
      memset(pCsr->aCnt, 0, nCol * sizeof(i64));
      memset(pCsr->aDoc, 0, nCol * sizeof(i64));
      pCsr->iCol = 0;

      assert( pTab->eType==FTS5_VOCAB_COL || pTab->eType==FTS5_VOCAB_ROW );
      while( rc==SQLITE_OK ){
        i64 dummy;
        const u8 *pPos; int nPos;   /* Position list */
        i64 iPos = 0;               /* 64-bit position read from poslist */
        int iOff = 0;               /* Current offset within position list */

        rc = sqlite3Fts5IterPoslist(pCsr->pIter, 0, &pPos, &nPos, &dummy);
        if( rc==SQLITE_OK ){




          if( pTab->eType==FTS5_VOCAB_ROW ){
            while( 0==sqlite3Fts5PoslistNext64(pPos, nPos, &iOff, &iPos) ){
              pCsr->aCnt[0]++;
            }
            pCsr->aDoc[0]++;
          }else{
            int iCol = -1;
            while( 0==sqlite3Fts5PoslistNext64(pPos, nPos, &iOff, &iPos) ){
              int ii = FTS5_POS2COLUMN(iPos);
              pCsr->aCnt[ii]++;
              if( iCol!=ii ){




                pCsr->aDoc[ii]++;
                iCol = ii;
              }
            }
          }
























          rc = sqlite3Fts5IterNextScan(pCsr->pIter);
        }

        if( rc==SQLITE_OK ){
          zTerm = sqlite3Fts5IterTerm(pCsr->pIter, &nTerm);
          if( nTerm!=pCsr->term.n || memcmp(zTerm, pCsr->term.p, nTerm) ){
            break;
................................................................................
          }
          if( sqlite3Fts5IterEof(pCsr->pIter) ) break;
        }
      }
    }
  }

  if( pCsr->bEof==0 && pTab->eType==FTS5_VOCAB_COL ){
    while( pCsr->aCnt[pCsr->iCol]==0 ) pCsr->iCol++;
    assert( pCsr->iCol<pCsr->pConfig->nCol );
  }
  return rc;
}

/*
** This is the xFilter implementation for the virtual table.
*/
static int fts5VocabFilterMethod(
  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
  int idxNum,                     /* Strategy index */
  const char *idxStr,             /* Unused */
  int nVal,                       /* Number of elements in apVal */
  sqlite3_value **apVal           /* Arguments for the indexing scheme */
){
  Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;
  int rc = SQLITE_OK;

  int iVal = 0;
  int f = FTS5INDEX_QUERY_SCAN;
  const char *zTerm = 0;
  int nTerm = 0;

  sqlite3_value *pEq = 0;
  sqlite3_value *pGe = 0;
  sqlite3_value *pLe = 0;



  fts5VocabResetCursor(pCsr);
  if( idxNum & FTS5_VOCAB_TERM_EQ ) pEq = apVal[iVal++];
  if( idxNum & FTS5_VOCAB_TERM_GE ) pGe = apVal[iVal++];
  if( idxNum & FTS5_VOCAB_TERM_LE ) pLe = apVal[iVal++];

  if( pEq ){
................................................................................

static int fts5VocabColumnMethod(
  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
  int iCol                        /* Index of column to read value from */
){
  Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;




  if( iCol==0 ){
    sqlite3_result_text(
        pCtx, (const char*)pCsr->term.p, pCsr->term.n, SQLITE_TRANSIENT
    );
  }
  else if( ((Fts5VocabTable*)(pCursor->pVtab))->eType==FTS5_VOCAB_COL ){
    assert( iCol==1 || iCol==2 || iCol==3 );
    if( iCol==1 ){

      const char *z = pCsr->pConfig->azCol[pCsr->iCol];
      sqlite3_result_text(pCtx, z, -1, SQLITE_STATIC);

    }else if( iCol==2 ){
      sqlite3_result_int64(pCtx, pCsr->aDoc[pCsr->iCol]);
    }else{
      sqlite3_result_int64(pCtx, pCsr->aCnt[pCsr->iCol]);
    }
  }else{
    assert( iCol==1 || iCol==2 );
    if( iCol==1 ){
      sqlite3_result_int64(pCtx, pCsr->aDoc[0]);
    }else{
      sqlite3_result_int64(pCtx, pCsr->aCnt[0]);
    }
  }


  return SQLITE_OK;
}

/* 
** This is the xRowid method. The SQLite core calls this routine to
** retrieve the rowid for the current row of the result set. The
** rowid should be written to *pRowid.

/******************************************************************************
** This file is an amalgamation of many separate C source files from SQLite
** version 3.11.0.  By combining all the individual C code files into this 
** single large file, the entire code can be compiled as a single translation
** unit.  This allows many compilers to do optimizations that would not be
** possible if the files were compiled separately.  Performance improvements
** of 5% or more are commonly seen when SQLite is compiled as a single
** translation unit.
**
** This file is all you need to compile SQLite.  To use SQLite in other
................................................................................
#define SQLITE_HOMEGROWN_RECURSIVE_MUTEX 1
#define SQLITE_OMIT_LOAD_EXTENSION 1
#define SQLITE_ENABLE_LOCKING_STYLE 0
#define HAVE_UTIME 1
#else
/* This is not VxWorks. */
#define OS_VXWORKS 0
#define HAVE_FCHOWN 1
#define HAVE_READLINK 1
#define HAVE_LSTAT 1
#endif /* defined(_WRS_KERNEL) */

/************** End of vxworks.h *********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/

/*
** These #defines should enable >2GB file support on POSIX if the
................................................................................
** string contains the date and time of the check-in (UTC) and an SHA1
** hash of the entire source tree.
**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.11.0"
#define SQLITE_VERSION_NUMBER 3011000
#define SQLITE_SOURCE_ID      "2016-02-12 18:48:09 a049fbbde5da2e43d41aa8c2b41f9eb21507ac76"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
................................................................................
** ^If an error occurs while evaluating the SQL statements passed into
** sqlite3_exec(), then execution of the current statement stops and
** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
** is not NULL then any error message is written into memory obtained
** from [sqlite3_malloc()] and passed back through the 5th parameter.
** To avoid memory leaks, the application should invoke [sqlite3_free()]
** on error message strings returned through the 5th parameter of
** sqlite3_exec() after the error message string is no longer needed.
** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
** NULL before returning.
**
** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
** routine returns SQLITE_ABORT without invoking the callback again and
** without running any subsequent SQL statements.
................................................................................
** sqlite3_libversion_number() returns a value greater than or equal to
** 3009000.
*/
struct sqlite3_index_info {
  /* Inputs */
  int nConstraint;           /* Number of entries in aConstraint */
  struct sqlite3_index_constraint {
     int iColumn;              /* Column constrained.  -1 for ROWID */
     unsigned char op;         /* Constraint operator */
     unsigned char usable;     /* True if this constraint is usable */
     int iTermOffset;          /* Used internally - xBestIndex should ignore */
  } *aConstraint;            /* Table of WHERE clause constraints */
  int nOrderBy;              /* Number of terms in the ORDER BY clause */
  struct sqlite3_index_orderby {
     int iColumn;              /* Column number */
................................................................................
**   *pnToken to the number of tokens in column iCol of the current row.
**
**   If parameter iCol is greater than or equal to the number of columns
**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
**   an OOM condition or IO error), an appropriate SQLite error code is 
**   returned.
**
**   This function may be quite inefficient if used with an FTS5 table
**   created with the "columnsize=0" option.
**
** xColumnText:
**   This function attempts to retrieve the text of column iCol of the
**   current document. If successful, (*pz) is set to point to a buffer
**   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
**   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
**   if an error occurs, an SQLite error code is returned and the final values
**   of (*pz) and (*pn) are undefined.
................................................................................
**   are numbered starting from zero.
**
** xInstCount:
**   Set *pnInst to the total number of occurrences of all phrases within
**   the query within the current row. Return SQLITE_OK if successful, or
**   an error code (i.e. SQLITE_NOMEM) if an error occurs.
**
**   This API can be quite slow if used with an FTS5 table created with the
**   "detail=none" or "detail=column" option. If the