/****************************************************************************** ** This file is an amalgamation of many separate C source files from SQLite ** version 3.7.12. 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 ** programs, you need this file and the "sqlite3.h" header file that defines ** the programming interface to the SQLite library. (If you do not have ** the "sqlite3.h" header file at hand, you will find a copy embedded within ** the text of this file. Search for "Begin file sqlite3.h" to find the start ** of the embedded sqlite3.h header file.) Additional code files may be needed ** if you want a wrapper to interface SQLite with your choice of programming ** language. The code for the "sqlite3" command-line shell is also in a ** separate file. This file contains only code for the core SQLite library. */ #define SQLITE_CORE 1 #define SQLITE_AMALGAMATION 1 #ifndef SQLITE_PRIVATE # define SQLITE_PRIVATE static #endif #ifndef SQLITE_API # define SQLITE_API #endif /************** Begin file sqliteInt.h ***************************************/ /* ** 2001 September 15 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** Internal interface definitions for SQLite. ** */ #ifndef _SQLITEINT_H_ #define _SQLITEINT_H_ /* ** These #defines should enable >2GB file support on POSIX if the ** underlying operating system supports it. If the OS lacks ** large file support, or if the OS is windows, these should be no-ops. ** ** Ticket #2739: The _LARGEFILE_SOURCE macro must appear before any ** system #includes. Hence, this block of code must be the very first ** code in all source files. ** ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch ** on the compiler command line. This is necessary if you are compiling ** on a recent machine (ex: Red Hat 7.2) but you want your code to work ** on an older machine (ex: Red Hat 6.0). If you compile on Red Hat 7.2 ** without this option, LFS is enable. But LFS does not exist in the kernel ** in Red Hat 6.0, so the code won't work. Hence, for maximum binary ** portability you should omit LFS. ** ** Similar is true for Mac OS X. LFS is only supported on Mac OS X 9 and later. */ #ifndef SQLITE_DISABLE_LFS # define _LARGE_FILE 1 # ifndef _FILE_OFFSET_BITS # define _FILE_OFFSET_BITS 64 # endif # define _LARGEFILE_SOURCE 1 #endif /* ** Include the configuration header output by 'configure' if we're using the ** autoconf-based build */ #ifdef _HAVE_SQLITE_CONFIG_H #include "config.h" #endif /************** Include sqliteLimit.h in the middle of sqliteInt.h ***********/ /************** Begin file sqliteLimit.h *************************************/ /* ** 2007 May 7 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** ** This file defines various limits of what SQLite can process. */ /* ** The maximum length of a TEXT or BLOB in bytes. This also ** limits the size of a row in a table or index. ** ** The hard limit is the ability of a 32-bit signed integer ** to count the size: 2^31-1 or 2147483647. */ #ifndef SQLITE_MAX_LENGTH # define SQLITE_MAX_LENGTH 1000000000 #endif /* ** This is the maximum number of ** ** * Columns in a table ** * Columns in an index ** * Columns in a view ** * Terms in the SET clause of an UPDATE statement ** * Terms in the result set of a SELECT statement ** * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement. ** * Terms in the VALUES clause of an INSERT statement ** ** The hard upper limit here is 32676. Most database people will ** tell you that in a well-normalized database, you usually should ** not have more than a dozen or so columns in any table. And if ** that is the case, there is no point in having more than a few ** dozen values in any of the other situations described above. */ #ifndef SQLITE_MAX_COLUMN # define SQLITE_MAX_COLUMN 2000 #endif /* ** The maximum length of a single SQL statement in bytes. ** ** It used to be the case that setting this value to zero would ** turn the limit off. That is no longer true. It is not possible ** to turn this limit off. */ #ifndef SQLITE_MAX_SQL_LENGTH # define SQLITE_MAX_SQL_LENGTH 1000000000 #endif /* ** The maximum depth of an expression tree. This is limited to ** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might ** want to place more severe limits on the complexity of an ** expression. ** ** A value of 0 used to mean that the limit was not enforced. ** But that is no longer true. The limit is now strictly enforced ** at all times. */ #ifndef SQLITE_MAX_EXPR_DEPTH # define SQLITE_MAX_EXPR_DEPTH 1000 #endif /* ** The maximum number of terms in a compound SELECT statement. ** The code generator for compound SELECT statements does one ** level of recursion for each term. A stack overflow can result ** if the number of terms is too large. In practice, most SQL ** never has more than 3 or 4 terms. Use a value of 0 to disable ** any limit on the number of terms in a compount SELECT. */ #ifndef SQLITE_MAX_COMPOUND_SELECT # define SQLITE_MAX_COMPOUND_SELECT 500 #endif /* ** The maximum number of opcodes in a VDBE program. ** Not currently enforced. */ #ifndef SQLITE_MAX_VDBE_OP # define SQLITE_MAX_VDBE_OP 25000 #endif /* ** The maximum number of arguments to an SQL function. */ #ifndef SQLITE_MAX_FUNCTION_ARG # define SQLITE_MAX_FUNCTION_ARG 127 #endif /* ** The maximum number of in-memory pages to use for the main database ** table and for temporary tables. The SQLITE_DEFAULT_CACHE_SIZE */ #ifndef SQLITE_DEFAULT_CACHE_SIZE # define SQLITE_DEFAULT_CACHE_SIZE 2000 #endif #ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE # define SQLITE_DEFAULT_TEMP_CACHE_SIZE 500 #endif /* ** The default number of frames to accumulate in the log file before ** checkpointing the database in WAL mode. */ #ifndef SQLITE_DEFAULT_WAL_AUTOCHECKPOINT # define SQLITE_DEFAULT_WAL_AUTOCHECKPOINT 1000 #endif /* ** The maximum number of attached databases. This must be between 0 ** and 62. The upper bound on 62 is because a 64-bit integer bitmap ** is used internally to track attached databases. */ #ifndef SQLITE_MAX_ATTACHED # define SQLITE_MAX_ATTACHED 10 #endif /* ** The maximum value of a ?nnn wildcard that the parser will accept. */ #ifndef SQLITE_MAX_VARIABLE_NUMBER # define SQLITE_MAX_VARIABLE_NUMBER 999 #endif /* Maximum page size. The upper bound on this value is 65536. This a limit ** imposed by the use of 16-bit offsets within each page. ** ** Earlier versions of SQLite allowed the user to change this value at ** compile time. This is no longer permitted, on the grounds that it creates ** a library that is technically incompatible with an SQLite library ** compiled with a different limit. If a process operating on a database ** with a page-size of 65536 bytes crashes, then an instance of SQLite ** compiled with the default page-size limit will not be able to rollback ** the aborted transaction. This could lead to database corruption. */ #ifdef SQLITE_MAX_PAGE_SIZE # undef SQLITE_MAX_PAGE_SIZE #endif #define SQLITE_MAX_PAGE_SIZE 65536 /* ** The default size of a database page. */ #ifndef SQLITE_DEFAULT_PAGE_SIZE # define SQLITE_DEFAULT_PAGE_SIZE 1024 #endif #if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE # undef SQLITE_DEFAULT_PAGE_SIZE # define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE #endif /* ** Ordinarily, if no value is explicitly provided, SQLite creates databases ** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain ** device characteristics (sector-size and atomic write() support), ** SQLite may choose a larger value. This constant is the maximum value ** SQLite will choose on its own. */ #ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE # define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192 #endif #if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE # undef SQLITE_MAX_DEFAULT_PAGE_SIZE # define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE #endif /* ** Maximum number of pages in one database file. ** ** This is really just the default value for the max_page_count pragma. ** This value can be lowered (or raised) at run-time using that the ** max_page_count macro. */ #ifndef SQLITE_MAX_PAGE_COUNT # define SQLITE_MAX_PAGE_COUNT 1073741823 #endif /* ** Maximum length (in bytes) of the pattern in a LIKE or GLOB ** operator. */ #ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH # define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000 #endif /* ** Maximum depth of recursion for triggers. ** ** A value of 1 means that a trigger program will not be able to itself ** fire any triggers. A value of 0 means that no trigger programs at all ** may be executed. */ #ifndef SQLITE_MAX_TRIGGER_DEPTH # define SQLITE_MAX_TRIGGER_DEPTH 1000 #endif /************** End of sqliteLimit.h *****************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ /* Disable nuisance warnings on Borland compilers */ #if defined(__BORLANDC__) #pragma warn -rch /* unreachable code */ #pragma warn -ccc /* Condition is always true or false */ #pragma warn -aus /* Assigned value is never used */ #pragma warn -csu /* Comparing signed and unsigned */ #pragma warn -spa /* Suspicious pointer arithmetic */ #endif /* Needed for various definitions... */ #ifndef _GNU_SOURCE # define _GNU_SOURCE #endif /* ** Include standard header files as necessary */ #ifdef HAVE_STDINT_H #include #endif #ifdef HAVE_INTTYPES_H #include #endif /* ** The following macros are used to cast pointers to integers and ** integers to pointers. The way you do this varies from one compiler ** to the next, so we have developed the following set of #if statements ** to generate appropriate macros for a wide range of compilers. ** ** The correct "ANSI" way to do this is to use the intptr_t type. ** Unfortunately, that typedef is not available on all compilers, or ** if it is available, it requires an #include of specific headers ** that vary from one machine to the next. ** ** Ticket #3860: The llvm-gcc-4.2 compiler from Apple chokes on ** the ((void*)&((char*)0)[X]) construct. But MSVC chokes on ((void*)(X)). ** So we have to define the macros in different ways depending on the ** compiler. */ #if defined(__PTRDIFF_TYPE__) /* This case should work for GCC */ # define SQLITE_INT_TO_PTR(X) ((void*)(__PTRDIFF_TYPE__)(X)) # define SQLITE_PTR_TO_INT(X) ((int)(__PTRDIFF_TYPE__)(X)) #elif !defined(__GNUC__) /* Works for compilers other than LLVM */ # define SQLITE_INT_TO_PTR(X) ((void*)&((char*)0)[X]) # define SQLITE_PTR_TO_INT(X) ((int)(((char*)X)-(char*)0)) #elif defined(HAVE_STDINT_H) /* Use this case if we have ANSI headers */ # define SQLITE_INT_TO_PTR(X) ((void*)(intptr_t)(X)) # define SQLITE_PTR_TO_INT(X) ((int)(intptr_t)(X)) #else /* Generates a warning - but it always works */ # define SQLITE_INT_TO_PTR(X) ((void*)(X)) # define SQLITE_PTR_TO_INT(X) ((int)(X)) #endif /* ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2. ** 0 means mutexes are permanently disable and the library is never ** threadsafe. 1 means the library is serialized which is the highest ** level of threadsafety. 2 means the libary is multithreaded - multiple ** threads can use SQLite as long as no two threads try to use the same ** database connection at the same time. ** ** Older versions of SQLite used an optional THREADSAFE macro. ** We support that for legacy. */ #if !defined(SQLITE_THREADSAFE) #if defined(THREADSAFE) # define SQLITE_THREADSAFE THREADSAFE #else # define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */ #endif #endif /* ** Powersafe overwrite is on by default. But can be turned off using ** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option. */ #ifndef SQLITE_POWERSAFE_OVERWRITE # define SQLITE_POWERSAFE_OVERWRITE 1 #endif /* ** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1. ** It determines whether or not the features related to ** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can ** be overridden at runtime using the sqlite3_config() API. */ #if !defined(SQLITE_DEFAULT_MEMSTATUS) # define SQLITE_DEFAULT_MEMSTATUS 1 #endif /* ** Exactly one of the following macros must be defined in order to ** specify which memory allocation subsystem to use. ** ** SQLITE_SYSTEM_MALLOC // Use normal system malloc() ** SQLITE_WIN32_MALLOC // Use Win32 native heap API ** SQLITE_MEMDEBUG // Debugging version of system malloc() ** ** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the ** assert() macro is enabled, each call into the Win32 native heap subsystem ** will cause HeapValidate to be called. If heap validation should fail, an ** assertion will be triggered. ** ** (Historical note: There used to be several other options, but we've ** pared it down to just these three.) ** ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as ** the default. */ #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)>1 # error "At most one of the following compile-time configuration options\ is allows: SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG" #endif #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)==0 # define SQLITE_SYSTEM_MALLOC 1 #endif /* ** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the ** sizes of memory allocations below this value where possible. */ #if !defined(SQLITE_MALLOC_SOFT_LIMIT) # define SQLITE_MALLOC_SOFT_LIMIT 1024 #endif /* ** We need to define _XOPEN_SOURCE as follows in order to enable ** recursive mutexes on most Unix systems. But Mac OS X is different. ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told, ** so it is omitted there. See ticket #2673. ** ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly ** implemented on some systems. So we avoid defining it at all ** if it is already defined or if it is unneeded because we are ** not doing a threadsafe build. Ticket #2681. ** ** See also ticket #2741. */ #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE # define _XOPEN_SOURCE 500 /* Needed to enable pthread recursive mutexes */ #endif /* ** The TCL headers are only needed when compiling the TCL bindings. */ #if defined(SQLITE_TCL) || defined(TCLSH) # include #endif /* ** Many people are failing to set -DNDEBUG=1 when compiling SQLite. ** Setting NDEBUG makes the code smaller and run faster. So the following ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1 ** option is set. Thus NDEBUG becomes an opt-in rather than an opt-out ** feature. */ #if !defined(NDEBUG) && !defined(SQLITE_DEBUG) # define NDEBUG 1 #endif /* ** The testcase() macro is used to aid in coverage testing. When ** doing coverage testing, the condition inside the argument to ** testcase() must be evaluated both true and false in order to ** get full branch coverage. The testcase() macro is inserted ** to help ensure adequate test coverage in places where simple ** condition/decision coverage is inadequate. For example, testcase() ** can be used to make sure boundary values are tested. For ** bitmask tests, testcase() can be used to make sure each bit ** is significant and used at least once. On switch statements ** where multiple cases go to the same block of code, testcase() ** can insure that all cases are evaluated. ** */ #ifdef SQLITE_COVERAGE_TEST SQLITE_PRIVATE void sqlite3Coverage(int); # define testcase(X) if( X ){ sqlite3Coverage(__LINE__); } #else # define testcase(X) #endif /* ** The TESTONLY macro is used to enclose variable declarations or ** other bits of code that are needed to support the arguments ** within testcase() and assert() macros. */ #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST) # define TESTONLY(X) X #else # define TESTONLY(X) #endif /* ** Sometimes we need a small amount of code such as a variable initialization ** to setup for a later assert() statement. We do not want this code to ** appear when assert() is disabled. The following macro is therefore ** used to contain that setup code. The "VVA" acronym stands for ** "Verification, Validation, and Accreditation". In other words, the ** code within VVA_ONLY() will only run during verification processes. */ #ifndef NDEBUG # define VVA_ONLY(X) X #else # define VVA_ONLY(X) #endif /* ** The ALWAYS and NEVER macros surround boolean expressions which ** are intended to always be true or false, respectively. Such ** expressions could be omitted from the code completely. But they ** are included in a few cases in order to enhance the resilience ** of SQLite to unexpected behavior - to make the code "self-healing" ** or "ductile" rather than being "brittle" and crashing at the first ** hint of unplanned behavior. ** ** In other words, ALWAYS and NEVER are added for defensive code. ** ** When doing coverage testing ALWAYS and NEVER are hard-coded to ** be true and false so that the unreachable code then specify will ** not be counted as untested code. */ #if defined(SQLITE_COVERAGE_TEST) # define ALWAYS(X) (1) # define NEVER(X) (0) #elif !defined(NDEBUG) # 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 /* ** Return true (non-zero) if the input is a integer that is too large ** to fit in 32-bits. This macro is used inside of various testcase() ** macros to verify that we have tested SQLite for large-file support. */ #define IS_BIG_INT(X) (((X)&~(i64)0xffffffff)!=0) /* ** The macro unlikely() is a hint that surrounds a boolean ** expression that is usually false. Macro likely() surrounds ** a boolean expression that is usually true. GCC is able to ** use these hints to generate better code, sometimes. */ #if defined(__GNUC__) && 0 # define likely(X) __builtin_expect((X),1) # define unlikely(X) __builtin_expect((X),0) #else # define likely(X) !!(X) # define unlikely(X) !!(X) #endif /************** Include sqlite3.h in the middle of sqliteInt.h ***************/ /************** Begin file sqlite3.h *****************************************/ /* ** 2001 September 15 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This header file defines the interface that the SQLite library ** presents to client programs. If a C-function, structure, datatype, ** or constant definition does not appear in this file, then it is ** not a published API of SQLite, is subject to change without ** notice, and should not be referenced by programs that use SQLite. ** ** Some of the definitions that are in this file are marked as ** "experimental". Experimental interfaces are normally new ** features recently added to SQLite. We do not anticipate changes ** to experimental interfaces but reserve the right to make minor changes ** if experience from use "in the wild" suggest such changes are prudent. ** ** The official C-language API documentation for SQLite is derived ** from comments in this file. This file is the authoritative source ** on how SQLite interfaces are suppose to operate. ** ** The name of this file under configuration management is "sqlite.h.in". ** The makefile makes some minor changes to this file (such as inserting ** the version number) and changes its name to "sqlite3.h" as ** part of the build process. */ #ifndef _SQLITE3_H_ #define _SQLITE3_H_ #include /* Needed for the definition of va_list */ /* ** Make sure we can call this stuff from C++. */ #if 0 extern "C" { #endif /* ** Add the ability to override 'extern' */ #ifndef SQLITE_EXTERN # define SQLITE_EXTERN extern #endif #ifndef SQLITE_API # define SQLITE_API #endif /* ** These no-op macros are used in front of interfaces to mark those ** interfaces as either deprecated or experimental. New applications ** should not use deprecated interfaces - they are support for backwards ** compatibility only. Application writers should be aware that ** experimental interfaces are subject to change in point releases. ** ** These macros used to resolve to various kinds of compiler magic that ** would generate warning messages when they were used. But that ** compiler magic ended up generating such a flurry of bug reports ** that we have taken it all out and gone back to using simple ** noop macros. */ #define SQLITE_DEPRECATED #define SQLITE_EXPERIMENTAL /* ** Ensure these symbols were not defined by some previous header file. */ #ifdef SQLITE_VERSION # undef SQLITE_VERSION #endif #ifdef SQLITE_VERSION_NUMBER # undef SQLITE_VERSION_NUMBER #endif /* ** CAPI3REF: Compile-Time Library Version Numbers ** ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header ** evaluates to a string literal that is the SQLite version in the ** format "X.Y.Z" where X is the major version number (always 3 for ** SQLite3) and Y is the minor version number and Z is the release number.)^ ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same ** numbers used in [SQLITE_VERSION].)^ ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also ** be larger than the release from which it is derived. Either Y will ** be held constant and Z will be incremented or else Y will be incremented ** and Z will be reset to zero. ** ** Since version 3.6.18, SQLite source code has been stored in the ** Fossil configuration management ** system. ^The SQLITE_SOURCE_ID macro evaluates to ** a string which identifies a particular check-in of SQLite ** within its configuration management system. ^The SQLITE_SOURCE_ID ** 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 "3.7.12" #define SQLITE_VERSION_NUMBER 3007012 #define SQLITE_SOURCE_ID "2012-05-14 01:41:23 8654aa9540fe9fd210899d83d17f3f407096c004" /* ** 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 ** but are associated with the library instead of the header file. ^(Cautious ** programmers might include assert() statements in their application to ** verify that values returned by these interfaces match the macros in ** the header, and thus insure that the application is ** compiled with matching library and header files. ** ** 
** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
**
)^ ** ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] ** macro. ^The sqlite3_libversion() function returns a pointer to the ** to the sqlite3_version[] string constant. The sqlite3_libversion() ** function is provided for use in DLLs since DLL users usually do not have ** direct access to string constants within the DLL. ^The ** sqlite3_libversion_number() function returns an integer equal to ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns ** a pointer to a string constant whose value is the same as the ** [SQLITE_SOURCE_ID] C preprocessor macro. ** ** See also: [sqlite_version()] and [sqlite_source_id()]. */ SQLITE_API const char sqlite3_version[] = SQLITE_VERSION; SQLITE_API const char *sqlite3_libversion(void); SQLITE_API const char *sqlite3_sourceid(void); SQLITE_API int sqlite3_libversion_number(void); /* ** CAPI3REF: Run-Time Library Compilation Options Diagnostics ** ** ^The sqlite3_compileoption_used() function returns 0 or 1 ** indicating whether the specified option was defined at ** compile time. ^The SQLITE_ prefix may be omitted from the ** option name passed to sqlite3_compileoption_used(). ** ** ^The sqlite3_compileoption_get() function allows iterating ** over the list of options that were defined at compile time by ** returning the N-th compile time option string. ^If N is out of range, ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ ** prefix is omitted from any strings returned by ** sqlite3_compileoption_get(). ** ** ^Support for the diagnostic functions sqlite3_compileoption_used() ** and sqlite3_compileoption_get() may be omitted by specifying the ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. ** ** See also: SQL functions [sqlite_compileoption_used()] and ** [sqlite_compileoption_get()] and the [compile_options pragma]. */ #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS SQLITE_API int sqlite3_compileoption_used(const char *zOptName); SQLITE_API const char *sqlite3_compileoption_get(int N); #endif /* ** CAPI3REF: Test To See If The Library Is Threadsafe ** ** ^The sqlite3_threadsafe() function returns zero if and only if ** SQLite was compiled with mutexing code omitted due to the ** [SQLITE_THREADSAFE] compile-time option being set to 0. ** ** SQLite can be compiled with or without mutexes. When ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes ** are enabled and SQLite is threadsafe. When the ** [SQLITE_THREADSAFE] macro is 0, ** the mutexes are omitted. Without the mutexes, it is not safe ** to use SQLite concurrently from more than one thread. ** ** Enabling mutexes incurs a measurable performance penalty. ** So if speed is of utmost importance, it makes sense to disable ** the mutexes. But for maximum safety, mutexes should be enabled. ** ^The default behavior is for mutexes to be enabled. ** ** This interface can be used by an application to make sure that the ** version of SQLite that it is linking against was compiled with ** the desired setting of the [SQLITE_THREADSAFE] macro. ** ** This interface only reports on the compile-time mutex setting ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but ** can be fully or partially disabled using a call to [sqlite3_config()] ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the ** sqlite3_threadsafe() function shows only the compile-time setting of ** thread safety, not any run-time changes to that setting made by ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() ** is unchanged by calls to sqlite3_config().)^ ** ** See the [threading mode] documentation for additional information. */ SQLITE_API int sqlite3_threadsafe(void); /* ** CAPI3REF: Database Connection Handle ** KEYWORDS: {database connection} {database connections} ** ** Each open SQLite database is represented by a pointer to an instance of ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] ** is its destructor. There are many other interfaces (such as ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and ** [sqlite3_busy_timeout()] to name but three) that are methods on an ** sqlite3 object. */ typedef struct sqlite3 sqlite3; /* ** CAPI3REF: 64-Bit Integer Types ** KEYWORDS: sqlite_int64 sqlite_uint64 ** ** Because there is no cross-platform way to specify 64-bit integer types ** SQLite includes typedefs for 64-bit signed and unsigned integers. ** ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. ** The sqlite_int64 and sqlite_uint64 types are supported for backwards ** compatibility only. ** ** ^The sqlite3_int64 and sqlite_int64 types can store integer values ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The ** sqlite3_uint64 and sqlite_uint64 types can store integer values ** between 0 and +18446744073709551615 inclusive. */ #ifdef SQLITE_INT64_TYPE typedef SQLITE_INT64_TYPE sqlite_int64; typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; #elif defined(_MSC_VER) || defined(__BORLANDC__) typedef __int64 sqlite_int64; typedef unsigned __int64 sqlite_uint64; #else typedef long long int sqlite_int64; typedef unsigned long long int sqlite_uint64; #endif typedef sqlite_int64 sqlite3_int64; typedef sqlite_uint64 sqlite3_uint64; /* ** If compiling for a processor that lacks floating point support, ** substitute integer for floating-point. */ #ifdef SQLITE_OMIT_FLOATING_POINT # define double sqlite3_int64 #endif /* ** CAPI3REF: Closing A Database Connection ** ** ^The sqlite3_close() routine is the destructor for the [sqlite3] object. ** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is ** successfully destroyed and all associated resources are deallocated. ** ** Applications must [sqlite3_finalize | finalize] all [prepared statements] ** and [sqlite3_blob_close | close] all [BLOB handles] associated with ** the [sqlite3] object prior to attempting to close the object. ^If ** sqlite3_close() is called on a [database connection] that still has ** outstanding [prepared statements] or [BLOB handles], then it returns ** SQLITE_BUSY. ** ** ^If [sqlite3_close()] is invoked while a transaction is open, ** the transaction is automatically rolled back. ** ** The C parameter to [sqlite3_close(C)] must be either a NULL ** pointer or an [sqlite3] object pointer obtained ** from [sqlite3_open()], [sqlite3_open16()], or ** [sqlite3_open_v2()], and not previously closed. ** ^Calling sqlite3_close() with a NULL pointer argument is a ** harmless no-op. */ SQLITE_API int sqlite3_close(sqlite3 *); /* ** The type for a callback function. ** This is legacy and deprecated. It is included for historical ** compatibility and is not documented. */ typedef int (*sqlite3_callback)(void*,int,char**, char**); /* ** CAPI3REF: One-Step Query Execution Interface ** ** The sqlite3_exec() interface is a convenience wrapper around ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], ** that allows an application to run multiple statements of SQL ** without having to use a lot of C code. ** ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, ** semicolon-separate SQL statements passed into its 2nd argument, ** in the context of the [database connection] passed in as its 1st ** argument. ^If the callback function of the 3rd argument to ** sqlite3_exec() is not NULL, then it is invoked for each result row ** coming out of the evaluated SQL statements. ^The 4th argument to ** sqlite3_exec() is relayed through to the 1st argument of each ** callback invocation. ^If the callback pointer to sqlite3_exec() ** is NULL, then no callback is ever invoked and result rows are ** ignored. ** ** ^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. ** ** ^The 2nd argument to the sqlite3_exec() callback function is the ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() ** callback is an array of pointers to strings obtained as if from ** [sqlite3_column_text()], one for each column. ^If an element of a ** result row is NULL then the corresponding string pointer for the ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the ** sqlite3_exec() callback is an array of pointers to strings where each ** entry represents the name of corresponding result column as obtained ** from [sqlite3_column_name()]. ** ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer ** to an empty string, or a pointer that contains only whitespace and/or ** SQL comments, then no SQL statements are evaluated and the database ** is not changed. ** ** Restrictions: ** **
    **
  • The application must insure that the 1st parameter to sqlite3_exec() ** is a valid and open [database connection]. **
  • The application must not close [database connection] specified by ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. **
  • The application must not modify the SQL statement text passed into ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. **
*/ SQLITE_API int sqlite3_exec( sqlite3*, /* An open database */ const char *sql, /* SQL to be evaluated */ int (*callback)(void*,int,char**,char**), /* Callback function */ void *, /* 1st argument to callback */ char **errmsg /* Error msg written here */ ); /* ** CAPI3REF: Result Codes ** KEYWORDS: SQLITE_OK {error code} {error codes} ** KEYWORDS: {result code} {result codes} ** ** Many SQLite functions return an integer result code from the set shown ** here in order to indicate success or failure. ** ** New error codes may be added in future versions of SQLite. ** ** See also: [SQLITE_IOERR_READ | extended result codes], ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. */ #define SQLITE_OK 0 /* Successful result */ /* beginning-of-error-codes */ #define SQLITE_ERROR 1 /* SQL error or missing database */ #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ #define SQLITE_PERM 3 /* Access permission denied */ #define SQLITE_ABORT 4 /* Callback routine requested an abort */ #define SQLITE_BUSY 5 /* The database file is locked */ #define SQLITE_LOCKED 6 /* A table in the database is locked */ #define SQLITE_NOMEM 7 /* A malloc() failed */ #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ #define SQLITE_FULL 13 /* Insertion failed because database is full */ #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ #define SQLITE_EMPTY 16 /* Database is empty */ #define SQLITE_SCHEMA 17 /* The database schema changed */ #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ #define SQLITE_MISMATCH 20 /* Data type mismatch */ #define SQLITE_MISUSE 21 /* Library used incorrectly */ #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ #define SQLITE_AUTH 23 /* Authorization denied */ #define SQLITE_FORMAT 24 /* Auxiliary database format error */ #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ #define SQLITE_NOTADB 26 /* File opened that is not a database file */ #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ /* end-of-error-codes */ /* ** CAPI3REF: Extended Result Codes ** KEYWORDS: {extended error code} {extended error codes} ** KEYWORDS: {extended result code} {extended result codes} ** ** In its default configuration, SQLite API routines return one of 26 integer ** [SQLITE_OK | result codes]. However, experience has shown that many of ** these result codes are too coarse-grained. They do not provide as ** much information about problems as programmers might like. In an effort to ** address this, newer versions of SQLite (version 3.3.8 and later) include ** support for additional result codes that provide more detailed information ** about errors. The extended result codes are enabled or disabled ** on a per database connection basis using the ** [sqlite3_extended_result_codes()] API. ** ** Some of the available extended result codes are listed here. ** One may expect the number of extended result codes will be expand ** over time. Software that uses extended result codes should expect ** to see new result codes in future releases of SQLite. ** ** The SQLITE_OK result code will never be extended. It will always ** be exactly zero. */ #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) /* ** CAPI3REF: Flags For File Open Operations ** ** These bit values are intended for use in the ** 3rd parameter to the [sqlite3_open_v2()] interface and ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. */ #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ /* Reserved: 0x00F00000 */ /* ** CAPI3REF: Device Characteristics ** ** The xDeviceCharacteristics method of the [sqlite3_io_methods] ** object returns an integer which is a vector of the these ** bit values expressing I/O characteristics of the mass storage ** device that holds the file that the [sqlite3_io_methods] ** refers to. ** ** The SQLITE_IOCAP_ATOMIC property means that all writes of ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values ** mean that writes of blocks that are nnn bytes in size and ** are aligned to an address which is an integer multiple of ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means ** that when data is appended to a file, the data is appended ** first then the size of the file is extended, never the other ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that ** information is written to disk in the same order as calls ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that ** after reboot following a crash or power loss, the only bytes in a ** file that were written at the application level might have changed ** and that adjacent bytes, even bytes within the same sector are ** guaranteed to be unchanged. */ #define SQLITE_IOCAP_ATOMIC 0x00000001 #define SQLITE_IOCAP_ATOMIC512 0x00000002 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 /* ** CAPI3REF: File Locking Levels ** ** SQLite uses one of these integer values as the second ** argument to calls it makes to the xLock() and xUnlock() methods ** of an [sqlite3_io_methods] object. */ #define SQLITE_LOCK_NONE 0 #define SQLITE_LOCK_SHARED 1 #define SQLITE_LOCK_RESERVED 2 #define SQLITE_LOCK_PENDING 3 #define SQLITE_LOCK_EXCLUSIVE 4 /* ** CAPI3REF: Synchronization Type Flags ** ** When SQLite invokes the xSync() method of an ** [sqlite3_io_methods] object it uses a combination of ** these integer values as the second argument. ** ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the ** sync operation only needs to flush data to mass storage. Inode ** information need not be flushed. If the lower four bits of the flag ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. ** If the lower four bits equal SQLITE_SYNC_FULL, that means ** to use Mac OS X style fullsync instead of fsync(). ** ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL ** settings. The [synchronous pragma] determines when calls to the ** xSync VFS method occur and applies uniformly across all platforms. ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how ** energetic or rigorous or forceful the sync operations are and ** only make a difference on Mac OSX for the default SQLite code. ** (Third-party VFS implementations might also make the distinction ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the ** operating systems natively supported by SQLite, only Mac OSX ** cares about the difference.) */ #define SQLITE_SYNC_NORMAL 0x00002 #define SQLITE_SYNC_FULL 0x00003 #define SQLITE_SYNC_DATAONLY 0x00010 /* ** CAPI3REF: OS Interface Open File Handle ** ** An [sqlite3_file] object represents an open file in the ** [sqlite3_vfs | OS interface layer]. Individual OS interface ** implementations will ** want to subclass this object by appending additional fields ** for their own use. The pMethods entry is a pointer to an ** [sqlite3_io_methods] object that defines methods for performing ** I/O operations on the open file. */ typedef struct sqlite3_file sqlite3_file; struct sqlite3_file { const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ }; /* ** CAPI3REF: OS Interface File Virtual Methods Object ** ** Every file opened by the [sqlite3_vfs.xOpen] method populates an ** [sqlite3_file] object (or, more commonly, a subclass of the ** [sqlite3_file] object) with a pointer to an instance of this object. ** This object defines the methods used to perform various operations ** against the open file represented by the [sqlite3_file] object. ** ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element ** to NULL. ** ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] ** flag may be ORed in to indicate that only the data of the file ** and not its inode needs to be synced. ** ** The integer values to xLock() and xUnlock() are one of **
    **
  • [SQLITE_LOCK_NONE], **
  • [SQLITE_LOCK_SHARED], **
  • [SQLITE_LOCK_RESERVED], **
  • [SQLITE_LOCK_PENDING], or **
  • [SQLITE_LOCK_EXCLUSIVE]. **
** xLock() increases the lock. xUnlock() decreases the lock. ** The xCheckReservedLock() method checks whether any database connection, ** either in this process or in some other process, is holding a RESERVED, ** PENDING, or EXCLUSIVE lock on the file. It returns true ** if such a lock exists and false otherwise. ** ** The xFileControl() method is a generic interface that allows custom ** VFS implementations to directly control an open file using the ** [sqlite3_file_control()] interface. The second "op" argument is an ** integer opcode. The third argument is a generic pointer intended to ** point to a structure that may contain arguments or space in which to ** write return values. Potential uses for xFileControl() might be ** functions to enable blocking locks with timeouts, to change the ** locking strategy (for example to use dot-file locks), to inquire ** about the status of a lock, or to break stale locks. The SQLite ** core reserves all opcodes less than 100 for its own use. ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. ** Applications that define a custom xFileControl method should use opcodes ** greater than 100 to avoid conflicts. VFS implementations should ** return [SQLITE_NOTFOUND] for file control opcodes that they do not ** recognize. ** ** The xSectorSize() method returns the sector size of the ** device that underlies the file. The sector size is the ** minimum write that can be performed without disturbing ** other bytes in the file. The xDeviceCharacteristics() ** method returns a bit vector describing behaviors of the ** underlying device: ** **
    **
  • [SQLITE_IOCAP_ATOMIC] **
  • [SQLITE_IOCAP_ATOMIC512] **
  • [SQLITE_IOCAP_ATOMIC1K] **
  • [SQLITE_IOCAP_ATOMIC2K] **
  • [SQLITE_IOCAP_ATOMIC4K] **
  • [SQLITE_IOCAP_ATOMIC8K] **
  • [SQLITE_IOCAP_ATOMIC16K] **
  • [SQLITE_IOCAP_ATOMIC32K] **
  • [SQLITE_IOCAP_ATOMIC64K] **
  • [SQLITE_IOCAP_SAFE_APPEND] **
  • [SQLITE_IOCAP_SEQUENTIAL] **
** ** The SQLITE_IOCAP_ATOMIC property means that all writes of ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values ** mean that writes of blocks that are nnn bytes in size and ** are aligned to an address which is an integer multiple of ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means ** that when data is appended to a file, the data is appended ** first then the size of the file is extended, never the other ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that ** information is written to disk in the same order as calls ** to xWrite(). ** ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill ** in the unread portions of the buffer with zeros. A VFS that ** fails to zero-fill short reads might seem to work. However, ** failure to zero-fill short reads will eventually lead to ** database corruption. */ typedef struct sqlite3_io_methods sqlite3_io_methods; struct sqlite3_io_methods { int iVersion; int (*xClose)(sqlite3_file*); int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); int (*xSync)(sqlite3_file*, int flags); int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); int (*xLock)(sqlite3_file*, int); int (*xUnlock)(sqlite3_file*, int); int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); int (*xFileControl)(sqlite3_file*, int op, void *pArg); int (*xSectorSize)(sqlite3_file*); int (*xDeviceCharacteristics)(sqlite3_file*); /* Methods above are valid for version 1 */ int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); void (*xShmBarrier)(sqlite3_file*); int (*xShmUnmap)(sqlite3_file*, int deleteFlag); /* Methods above are valid for version 2 */ /* Additional methods may be added in future releases */ }; /* ** CAPI3REF: Standard File Control Opcodes ** ** These integer constants are opcodes for the xFileControl method ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] ** interface. ** ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This ** opcode causes the xFileControl method to write the current state of ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) ** into an integer that the pArg argument points to. This capability ** is used during testing and only needs to be supported when SQLITE_TEST ** is defined. **
    **
  • [[SQLITE_FCNTL_SIZE_HINT]] ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS ** layer a hint of how large the database file will grow to be during the ** current transaction. This hint is not guaranteed to be accurate but it ** is often close. The underlying VFS might choose to preallocate database ** file space based on this hint in order to help writes to the database ** file run faster. ** **
  • [[SQLITE_FCNTL_CHUNK_SIZE]] ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS ** extends and truncates the database file in chunks of a size specified ** by the user. The fourth argument to [sqlite3_file_control()] should ** point to an integer (type int) containing the new chunk-size to use ** for the nominated database. Allocating database file space in large ** chunks (say 1MB at a time), may reduce file-system fragmentation and ** improve performance on some systems. ** **
  • [[SQLITE_FCNTL_FILE_POINTER]] ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer ** to the [sqlite3_file] object associated with a particular database ** connection. See the [sqlite3_file_control()] documentation for ** additional information. ** **
  • [[SQLITE_FCNTL_SYNC_OMITTED]] ** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by ** SQLite and sent to all VFSes in place of a call to the xSync method ** when the database connection has [PRAGMA synchronous] set to OFF.)^ ** Some specialized VFSes need this signal in order to operate correctly ** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most ** VFSes do not need this signal and should silently ignore this opcode. ** Applications should not call [sqlite3_file_control()] with this ** opcode as doing so may disrupt the operation of the specialized VFSes ** that do require it. ** **
  • [[SQLITE_FCNTL_WIN32_AV_RETRY]] ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic ** retry counts and intervals for certain disk I/O operations for the ** windows [VFS] in order to provide robustness in the presence of ** anti-virus programs. By default, the windows VFS will retry file read, ** file write, and file delete operations up to 10 times, with a delay ** of 25 milliseconds before the first retry and with the delay increasing ** by an additional 25 milliseconds with each subsequent retry. This ** opcode allows these two values (10 retries and 25 milliseconds of delay) ** to be adjusted. The values are changed for all database connections ** within the same process. The argument is a pointer to an array of two ** integers where the first integer i the new retry count and the second ** integer is the delay. If either integer is negative, then the setting ** is not changed but instead the prior value of that setting is written ** into the array entry, allowing the current retry settings to be ** interrogated. The zDbName parameter is ignored. ** **
  • [[SQLITE_FCNTL_PERSIST_WAL]] ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary ** write ahead log and shared memory files used for transaction control ** are automatically deleted when the latest connection to the database ** closes. Setting persistent WAL mode causes those files to persist after ** close. Persisting the files is useful when other processes that do not ** have write permission on the directory containing the database file want ** to read the database file, as the WAL and shared memory files must exist ** in order for the database to be readable. The fourth parameter to ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent ** WAL mode. If the integer is -1, then it is overwritten with the current ** WAL persistence setting. ** **
  • [[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the ** xDeviceCharacteristics methods. The fourth parameter to ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage ** mode. If the integer is -1, then it is overwritten with the current ** zero-damage mode setting. ** **
  • [[SQLITE_FCNTL_OVERWRITE]] ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening ** a write transaction to indicate that, unless it is rolled back for some ** reason, the entire database file will be overwritten by the current ** transaction. This is used by VACUUM operations. ** **
  • [[SQLITE_FCNTL_VFSNAME]] ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of ** all [VFSes] in the VFS stack. The names are of all VFS shims and the ** final bottom-level VFS are written into memory obtained from ** [sqlite3_malloc()] and the result is stored in the char* variable ** that the fourth parameter of [sqlite3_file_control()] points to. ** The caller is responsible for freeing the memory when done. As with ** all file-control actions, there is no guarantee that this will actually ** do anything. Callers should initialize the char* variable to a NULL ** pointer in case this file-control is not implemented. This file-control ** is intended for diagnostic use only. ** **
  • [[SQLITE_FCNTL_PRAGMA]] ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] ** file control is sent to the open [sqlite3_file] object corresponding ** to the database file to which the pragma statement refers. ^The argument ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of ** pointers to strings (char**) in which the second element of the array ** is the name of the pragma and the third element is the argument to the ** pragma or NULL if the pragma has no argument. ^The handler for an ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element ** of the char** argument point to a string obtained from [sqlite3_mprintf()] ** or the equivalent and that string will become the result of the pragma or ** the error message if the pragma fails. ^If the ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] ** file control returns [SQLITE_OK], then the parser assumes that the ** VFS has handled the PRAGMA itself and the parser generates a no-op ** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means ** that the VFS encountered an error while handling the [PRAGMA] and the ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] ** file control occurs at the beginning of pragma statement analysis and so ** it is able to override built-in [PRAGMA] statements. **
*/ #define SQLITE_FCNTL_LOCKSTATE 1 #define SQLITE_GET_LOCKPROXYFILE 2 #define SQLITE_SET_LOCKPROXYFILE 3 #define SQLITE_LAST_ERRNO 4 #define SQLITE_FCNTL_SIZE_HINT 5 #define SQLITE_FCNTL_CHUNK_SIZE 6 #define SQLITE_FCNTL_FILE_POINTER 7 #define SQLITE_FCNTL_SYNC_OMITTED 8 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 #define SQLITE_FCNTL_PERSIST_WAL 10 #define SQLITE_FCNTL_OVERWRITE 11 #define SQLITE_FCNTL_VFSNAME 12 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 #define SQLITE_FCNTL_PRAGMA 14 /* ** CAPI3REF: Mutex Handle ** ** The mutex module within SQLite defines [sqlite3_mutex] to be an ** abstract type for a mutex object. The SQLite core never looks ** at the internal representation of an [sqlite3_mutex]. It only ** deals with pointers to the [sqlite3_mutex] object. ** ** Mutexes are created using [sqlite3_mutex_alloc()]. */ typedef struct sqlite3_mutex sqlite3_mutex; /* ** CAPI3REF: OS Interface Object ** ** An instance of the sqlite3_vfs object defines the interface between ** the SQLite core and the underlying operating system. The "vfs" ** in the name of the object stands for "virtual file system". See ** the [VFS | VFS documentation] for further information. ** ** The value of the iVersion field is initially 1 but may be larger in ** future versions of SQLite. Additional fields may be appended to this ** object when the iVersion value is increased. Note that the structure ** of the sqlite3_vfs object changes in the transaction between ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not ** modified. ** ** The szOsFile field is the size of the subclassed [sqlite3_file] ** structure used by this VFS. mxPathname is the maximum length of ** a pathname in this VFS. ** ** Registered sqlite3_vfs objects are kept on a linked list formed by ** the pNext pointer. The [sqlite3_vfs_register()] ** and [sqlite3_vfs_unregister()] interfaces manage this list ** in a thread-safe way. The [sqlite3_vfs_find()] interface ** searches the list. Neither the application code nor the VFS ** implementation should use the pNext pointer. ** ** The pNext field is the only field in the sqlite3_vfs ** structure that SQLite will ever modify. SQLite will only access ** or modify this field while holding a particular static mutex. ** The application should never modify anything within the sqlite3_vfs ** object once the object has been registered. ** ** The zName field holds the name of the VFS module. The name must ** be unique across all VFS modules. ** ** [[sqlite3_vfs.xOpen]] ** ^SQLite guarantees that the zFilename parameter to xOpen ** is either a NULL pointer or string obtained ** from xFullPathname() with an optional suffix added. ** ^If a suffix is added to the zFilename parameter, it will ** consist of a single "-" character followed by no more than ** 11 alphanumeric and/or "-" characters. ** ^SQLite further guarantees that ** the string will be valid and unchanged until xClose() is ** called. Because of the previous sentence, ** the [sqlite3_file] can safely store a pointer to the ** filename if it needs to remember the filename for some reason. ** If the zFilename parameter to xOpen is a NULL pointer then xOpen ** must invent its own temporary name for the file. ^Whenever the ** xFilename parameter is NULL it will also be the case that the ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. ** ** The flags argument to xOpen() includes all bits set in ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] ** or [sqlite3_open16()] is used, then flags includes at least ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. ** If xOpen() opens a file read-only then it sets *pOutFlags to ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. ** ** ^(SQLite will also add one of the following flags to the xOpen() ** call, depending on the object being opened: ** **
    **
  • [SQLITE_OPEN_MAIN_DB] **
  • [SQLITE_OPEN_MAIN_JOURNAL] **
  • [SQLITE_OPEN_TEMP_DB] **
  • [SQLITE_OPEN_TEMP_JOURNAL] **
  • [SQLITE_OPEN_TRANSIENT_DB] **
  • [SQLITE_OPEN_SUBJOURNAL] **
  • [SQLITE_OPEN_MASTER_JOURNAL] **
  • [SQLITE_OPEN_WAL] **
)^ ** ** The file I/O implementation can use the object type flags to ** change the way it deals with files. For example, an application ** that does not care about crash recovery or rollback might make ** the open of a journal file a no-op. Writes to this journal would ** also be no-ops, and any attempt to read the journal would return ** SQLITE_IOERR. Or the implementation might recognize that a database ** file will be doing page-aligned sector reads and writes in a random ** order and set up its I/O subsystem accordingly. ** ** SQLite might also add one of the following flags to the xOpen method: ** **
    **
  • [SQLITE_OPEN_DELETEONCLOSE] **
  • [SQLITE_OPEN_EXCLUSIVE] **
** ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] ** will be set for TEMP databases and their journals, transient ** databases, and subjournals. ** ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction ** with the [SQLITE_OPEN_CREATE] flag, which are both directly ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the ** SQLITE_OPEN_CREATE, is used to indicate that file should always ** be created, and that it is an error if it already exists. ** It is not used to indicate the file should be opened ** for exclusive access. ** ** ^At least szOsFile bytes of memory are allocated by SQLite ** to hold the [sqlite3_file] structure passed as the third ** argument to xOpen. The xOpen method does not have to ** allocate the structure; it should just fill it in. Note that ** the xOpen method must set the sqlite3_file.pMethods to either ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods ** element will be valid after xOpen returns regardless of the success ** or failure of the xOpen call. ** ** [[sqlite3_vfs.xAccess]] ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] ** to test whether a file is at least readable. The file can be a ** directory. ** ** ^SQLite will always allocate at least mxPathname+1 bytes for the ** output buffer xFullPathname. The exact size of the output buffer ** is also passed as a parameter to both methods. If the output buffer ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is ** handled as a fatal error by SQLite, vfs implementations should endeavor ** to prevent this by setting mxPathname to a sufficiently large value. ** ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() ** interfaces are not strictly a part of the filesystem, but they are ** included in the VFS structure for completeness. ** The xRandomness() function attempts to return nBytes bytes ** of good-quality randomness into zOut. The return value is ** the actual number of bytes of randomness obtained. ** The xSleep() method causes the calling thread to sleep for at ** least the number of microseconds given. ^The xCurrentTime() ** method returns a Julian Day Number for the current date and time as ** a floating point value. ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian ** Day Number multiplied by 86400000 (the number of milliseconds in ** a 24-hour day). ** ^SQLite will use the xCurrentTimeInt64() method to get the current ** date and time if that method is available (if iVersion is 2 or ** greater and the function pointer is not NULL) and will fall back ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. ** ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces ** are not used by the SQLite core. These optional interfaces are provided ** by some VFSes to facilitate testing of the VFS code. By overriding ** system calls with functions under its control, a test program can ** simulate faults and error conditions that would otherwise be difficult ** or impossible to induce. The set of system calls that can be overridden ** varies from one VFS to another, and from one version of the same VFS to the ** next. Applications that use these interfaces must be prepared for any ** or all of these interfaces to be NULL or for their behavior to change ** from one release to the next. Applications must not attempt to access ** any of these methods if the iVersion of the VFS is less than 3. */ typedef struct sqlite3_vfs sqlite3_vfs; typedef void (*sqlite3_syscall_ptr)(void); struct sqlite3_vfs { int iVersion; /* Structure version number (currently 3) */ int szOsFile; /* Size of subclassed sqlite3_file */ int mxPathname; /* Maximum file pathname length */ sqlite3_vfs *pNext; /* Next registered VFS */ const char *zName; /* Name of this virtual file system */ void *pAppData; /* Pointer to application-specific data */ int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, int flags, int *pOutFlags); int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); void (*xDlClose)(sqlite3_vfs*, void*); int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); int (*xSleep)(sqlite3_vfs*, int microseconds); int (*xCurrentTime)(sqlite3_vfs*, double*); int (*xGetLastError)(sqlite3_vfs*, int, char *); /* ** The methods above are in version 1 of the sqlite_vfs object ** definition. Those that follow are added in version 2 or later */ int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); /* ** The methods above are in versions 1 and 2 of the sqlite_vfs object. ** Those below are for version 3 and greater. */ int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); /* ** The methods above are in versions 1 through 3 of the sqlite_vfs object. ** New fields may be appended in figure versions. The iVersion ** value will increment whenever this happens. */ }; /* ** CAPI3REF: Flags for the xAccess VFS method ** ** These integer constants can be used as the third parameter to ** the xAccess method of an [sqlite3_vfs] object. They determine ** what kind of permissions the xAccess method is looking for. ** With SQLITE_ACCESS_EXISTS, the xAccess method ** simply checks whether the file exists. ** With SQLITE_ACCESS_READWRITE, the xAccess method ** checks whether the named directory is both readable and writable ** (in other words, if files can be added, removed, and renamed within ** the directory). ** The SQLITE_ACCESS_READWRITE constant is currently used only by the ** [temp_store_directory pragma], though this could change in a future ** release of SQLite. ** With SQLITE_ACCESS_READ, the xAccess method ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is ** currently unused, though it might be used in a future release of ** SQLite. */ #define SQLITE_ACCESS_EXISTS 0 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ #define SQLITE_ACCESS_READ 2 /* Unused */ /* ** CAPI3REF: Flags for the xShmLock VFS method ** ** These integer constants define the various locking operations ** allowed by the xShmLock method of [sqlite3_io_methods]. The ** following are the only legal combinations of flags to the ** xShmLock method: ** **
    **
  • SQLITE_SHM_LOCK | SQLITE_SHM_SHARED **
  • SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE **
  • SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED **
  • SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE **
** ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as ** was given no the corresponding lock. ** ** The xShmLock method can transition between unlocked and SHARED or ** between unlocked and EXCLUSIVE. It cannot transition between SHARED ** and EXCLUSIVE. */ #define SQLITE_SHM_UNLOCK 1 #define SQLITE_SHM_LOCK 2 #define SQLITE_SHM_SHARED 4 #define SQLITE_SHM_EXCLUSIVE 8 /* ** CAPI3REF: Maximum xShmLock index ** ** The xShmLock method on [sqlite3_io_methods] may use values ** between 0 and this upper bound as its "offset" argument. ** The SQLite core will never attempt to acquire or release a ** lock outside of this range */ #define SQLITE_SHM_NLOCK 8 /* ** CAPI3REF: Initialize The SQLite Library ** ** ^The sqlite3_initialize() routine initializes the ** SQLite library. ^The sqlite3_shutdown() routine ** deallocates any resources that were allocated by sqlite3_initialize(). ** These routines are designed to aid in process initialization and ** shutdown on embedded systems. Workstation applications using ** SQLite normally do not need to invoke either of these routines. ** ** A call to sqlite3_initialize() is an "effective" call if it is ** the first time sqlite3_initialize() is invoked during the lifetime of ** the process, or if it is the first time sqlite3_initialize() is invoked ** following a call to sqlite3_shutdown(). ^(Only an effective call ** of sqlite3_initialize() does any initialization. All other calls ** are harmless no-ops.)^ ** ** A call to sqlite3_shutdown() is an "effective" call if it is the first ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only ** an effective call to sqlite3_shutdown() does any deinitialization. ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ ** ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() ** is not. The sqlite3_shutdown() interface must only be called from a ** single thread. All open [database connections] must be closed and all ** other SQLite resources must be deallocated prior to invoking ** sqlite3_shutdown(). ** ** Among other things, ^sqlite3_initialize() will invoke ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() ** will invoke sqlite3_os_end(). ** ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. ** ^If for some reason, sqlite3_initialize() is unable to initialize ** the library (perhaps it is unable to allocate a needed resource such ** as a mutex) it returns an [error code] other than [SQLITE_OK]. ** ** ^The sqlite3_initialize() routine is called internally by many other ** SQLite interfaces so that an application usually does not need to ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] ** calls sqlite3_initialize() so the SQLite library will be automatically ** initialized when [sqlite3_open()] is called if it has not be initialized ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] ** compile-time option, then the automatic calls to sqlite3_initialize() ** are omitted and the application must call sqlite3_initialize() directly ** prior to using any other SQLite interface. For maximum portability, ** it is recommended that applications always invoke sqlite3_initialize() ** directly prior to using any other SQLite interface. Future releases ** of SQLite may require this. In other words, the behavior exhibited ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the ** default behavior in some future release of SQLite. ** ** The sqlite3_os_init() routine does operating-system specific ** initialization of the SQLite library. The sqlite3_os_end() ** routine undoes the effect of sqlite3_os_init(). Typical tasks ** performed by these routines include allocation or deallocation ** of static resources, initialization of global variables, ** setting up a default [sqlite3_vfs] module, or setting up ** a default configuration using [sqlite3_config()]. ** ** The application should never invoke either sqlite3_os_init() ** or sqlite3_os_end() directly. The application should only invoke ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() ** interface is called automatically by sqlite3_initialize() and ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate ** implementations for sqlite3_os_init() and sqlite3_os_end() ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. ** When [custom builds | built for other platforms] ** (using the [SQLITE_OS_OTHER=1] compile-time ** option) the application must supply a suitable implementation for ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied ** implementation of sqlite3_os_init() or sqlite3_os_end() ** must return [SQLITE_OK] on success and some other [error code] upon ** failure. */ SQLITE_API int sqlite3_initialize(void); SQLITE_API int sqlite3_shutdown(void); SQLITE_API int sqlite3_os_init(void); SQLITE_API int sqlite3_os_end(void); /* ** CAPI3REF: Configuring The SQLite Library ** ** The sqlite3_config() interface is used to make global configuration ** changes to SQLite in order to tune SQLite to the specific needs of ** the application. The default configuration is recommended for most ** applications and so this routine is usually not necessary. It is ** provided to support rare applications with unusual needs. ** ** The sqlite3_config() interface is not threadsafe. The application ** must insure that no other SQLite interfaces are invoked by other ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() ** may only be invoked prior to library initialization using ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. ** Note, however, that ^sqlite3_config() can be called as part of the ** implementation of an application-defined [sqlite3_os_init()]. ** ** The first argument to sqlite3_config() is an integer ** [configuration option] that determines ** what property of SQLite is to be configured. Subsequent arguments ** vary depending on the [configuration option] ** in the first argument. ** ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. ** ^If the option is unknown or SQLite is unable to set the option ** then this routine returns a non-zero [error code]. */ SQLITE_API int sqlite3_config(int, ...); /* ** CAPI3REF: Configure database connections ** ** The sqlite3_db_config() interface is used to make configuration ** changes to a [database connection]. The interface is similar to ** [sqlite3_config()] except that the changes apply to a single ** [database connection] (specified in the first argument). ** ** The second argument to sqlite3_db_config(D,V,...) is the ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code ** that indicates what aspect of the [database connection] is being configured. ** Subsequent arguments vary depending on the configuration verb. ** ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if ** the call is considered successful. */ SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); /* ** CAPI3REF: Memory Allocation Routines ** ** An instance of this object defines the interface between SQLite ** and low-level memory allocation routines. ** ** This object is used in only one place in the SQLite interface. ** A pointer to an instance of this object is the argument to ** [sqlite3_config()] when the configuration option is ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. ** By creating an instance of this object ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) ** during configuration, an application can specify an alternative ** memory allocation subsystem for SQLite to use for all of its ** dynamic memory needs. ** ** Note that SQLite comes with several [built-in memory allocators] ** that are perfectly adequate for the overwhelming majority of applications ** and that this object is only useful to a tiny minority of applications ** with specialized memory allocation requirements. This object is ** also used during testing of SQLite in order to specify an alternative ** memory allocator that simulates memory out-of-memory conditions in ** order to verify that SQLite recovers gracefully from such ** conditions. ** ** The xMalloc, xRealloc, and xFree methods must work like the ** malloc(), realloc() and free() functions from the standard C library. ** ^SQLite guarantees that the second argument to ** xRealloc is always a value returned by a prior call to xRoundup. ** ** xSize should return the allocated size of a memory allocation ** previously obtained from xMalloc or xRealloc. The allocated size ** is always at least as big as the requested size but may be larger. ** ** The xRoundup method returns what would be the allocated size of ** a memory allocation given a particular requested size. Most memory ** allocators round up memory allocations at least to the next multiple ** of 8. Some allocators round up to a larger multiple or to a power of 2. ** Every memory allocation request coming in through [sqlite3_malloc()] ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, ** that causes the corresponding memory allocation to fail. ** ** The xInit method initializes the memory allocator. (For example, ** it might allocate any require mutexes or initialize internal data ** structures. The xShutdown method is invoked (indirectly) by ** [sqlite3_shutdown()] and should deallocate any resources acquired ** by xInit. The pAppData pointer is used as the only parameter to ** xInit and xShutdown. ** ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes ** the xInit method, so the xInit method need not be threadsafe. The ** xShutdown method is only called from [sqlite3_shutdown()] so it does ** not need to be threadsafe either. For all other methods, SQLite ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which ** it is by default) and so the methods are automatically serialized. ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other ** methods must be threadsafe or else make their own arrangements for ** serialization. ** ** SQLite will never invoke xInit() more than once without an intervening ** call to xShutdown(). */ typedef struct sqlite3_mem_methods sqlite3_mem_methods; struct sqlite3_mem_methods { void *(*xMalloc)(int); /* Memory allocation function */ void (*xFree)(void*); /* Free a prior allocation */ void *(*xRealloc)(void*,int); /* Resize an allocation */ int (*xSize)(void*); /* Return the size of an allocation */ int (*xRoundup)(int); /* Round up request size to allocation size */ int (*xInit)(void*); /* Initialize the memory allocator */ void (*xShutdown)(void*); /* Deinitialize the memory allocator */ void *pAppData; /* Argument to xInit() and xShutdown() */ }; /* ** CAPI3REF: Configuration Options ** KEYWORDS: {configuration option} ** ** These constants are the available integer configuration options that ** can be passed as the first argument to the [sqlite3_config()] interface. ** ** New configuration options may be added in future releases of SQLite. ** Existing configuration options might be discontinued. Applications ** should check the return code from [sqlite3_config()] to make sure that ** the call worked. The [sqlite3_config()] interface will return a ** non-zero [error code] if a discontinued or unsupported configuration option ** is invoked. ** **
** [[SQLITE_CONFIG_SINGLETHREAD]]
SQLITE_CONFIG_SINGLETHREAD
**
There are no arguments to this option. ^This option sets the ** [threading mode] to Single-thread. In other words, it disables ** all mutexing and puts SQLite into a mode where it can only be used ** by a single thread. ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** it is not possible to change the [threading mode] from its default ** value of Single-thread and so [sqlite3_config()] will return ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD ** configuration option.
** ** [[SQLITE_CONFIG_MULTITHREAD]]
SQLITE_CONFIG_MULTITHREAD
**
There are no arguments to this option. ^This option sets the ** [threading mode] to Multi-thread. In other words, it disables ** mutexing on [database connection] and [prepared statement] objects. ** The application is responsible for serializing access to ** [database connections] and [prepared statements]. But other mutexes ** are enabled so that SQLite will be safe to use in a multi-threaded ** environment as long as no two threads attempt to use the same ** [database connection] at the same time. ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** it is not possible to set the Multi-thread [threading mode] and ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the ** SQLITE_CONFIG_MULTITHREAD configuration option.
** ** [[SQLITE_CONFIG_SERIALIZED]]
SQLITE_CONFIG_SERIALIZED
**
There are no arguments to this option. ^This option sets the ** [threading mode] to Serialized. In other words, this option enables ** all mutexes including the recursive ** mutexes on [database connection] and [prepared statement] objects. ** In this mode (which is the default when SQLite is compiled with ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access ** to [database connections] and [prepared statements] so that the ** application is free to use the same [database connection] or the ** same [prepared statement] in different threads at the same time. ** ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** it is not possible to set the Serialized [threading mode] and ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the ** SQLITE_CONFIG_SERIALIZED configuration option.
** ** [[SQLITE_CONFIG_MALLOC]]
SQLITE_CONFIG_MALLOC
**
^(This option takes a single argument which is a pointer to an ** instance of the [sqlite3_mem_methods] structure. The argument specifies ** alternative low-level memory allocation routines to be used in place of ** the memory allocation routines built into SQLite.)^ ^SQLite makes ** its own private copy of the content of the [sqlite3_mem_methods] structure ** before the [sqlite3_config()] call returns.
** ** [[SQLITE_CONFIG_GETMALLOC]]
SQLITE_CONFIG_GETMALLOC
**
^(This option takes a single argument which is a pointer to an ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] ** structure is filled with the currently defined memory allocation routines.)^ ** This option can be used to overload the default memory allocation ** routines with a wrapper that simulations memory allocation failure or ** tracks memory usage, for example.
** ** [[SQLITE_CONFIG_MEMSTATUS]]
SQLITE_CONFIG_MEMSTATUS
**
^This option takes single argument of type int, interpreted as a ** boolean, which enables or disables the collection of memory allocation ** statistics. ^(When memory allocation statistics are disabled, the ** following SQLite interfaces become non-operational: **
    **
  • [sqlite3_memory_used()] **
  • [sqlite3_memory_highwater()] **
  • [sqlite3_soft_heap_limit64()] **
  • [sqlite3_status()] **
)^ ** ^Memory allocation statistics are enabled by default unless SQLite is ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory ** allocation statistics are disabled by default. **
** ** [[SQLITE_CONFIG_SCRATCH]]
SQLITE_CONFIG_SCRATCH
**
^This option specifies a static memory buffer that SQLite can use for ** scratch memory. There are three arguments: A pointer an 8-byte ** aligned memory buffer from which the scratch allocations will be ** drawn, the size of each scratch allocation (sz), ** and the maximum number of scratch allocations (N). The sz ** argument must be a multiple of 16. ** The first argument must be a pointer to an 8-byte aligned buffer ** of at least sz*N bytes of memory. ** ^SQLite will use no more than two scratch buffers per thread. So ** N should be set to twice the expected maximum number of threads. ** ^SQLite will never require a scratch buffer that is more than 6 ** times the database page size. ^If SQLite needs needs additional ** scratch memory beyond what is provided by this configuration option, then ** [sqlite3_malloc()] will be used to obtain the memory needed.
** ** [[SQLITE_CONFIG_PAGECACHE]]
SQLITE_CONFIG_PAGECACHE
**
^This option specifies a static memory buffer that SQLite can use for ** the database page cache with the default page cache implementation. ** This configuration should not be used if an application-define page ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. ** There are three arguments to this option: A pointer to 8-byte aligned ** memory, the size of each page buffer (sz), and the number of pages (N). ** The sz argument should be the size of the largest database page ** (a power of two between 512 and 32768) plus a little extra for each ** page header. ^The page header size is 20 to 40 bytes depending on ** the host architecture. ^It is harmless, apart from the wasted memory, ** to make sz a little too large. The first ** argument should point to an allocation of at least sz*N bytes of memory. ** ^SQLite will use the memory provided by the first argument to satisfy its ** memory needs for the first N pages that it adds to cache. ^If additional ** page cache memory is needed beyond what is provided by this option, then ** SQLite goes to [sqlite3_malloc()] for the additional storage space. ** The pointer in the first argument must ** be aligned to an 8-byte boundary or subsequent behavior of SQLite ** will be undefined.
** ** [[SQLITE_CONFIG_HEAP]]
SQLITE_CONFIG_HEAP
**
^This option specifies a static memory buffer that SQLite will use ** for all of its dynamic memory allocation needs beyond those provided ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. ** There are three arguments: An 8-byte aligned pointer to the memory, ** the number of bytes in the memory buffer, and the minimum allocation size. ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts ** to using its default memory allocator (the system malloc() implementation), ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory ** allocator is engaged to handle all of SQLites memory allocation needs. ** The first pointer (the memory pointer) must be aligned to an 8-byte ** boundary or subsequent behavior of SQLite will be undefined. ** The minimum allocation size is capped at 2**12. Reasonable values ** for the minimum allocation size are 2**5 through 2**8.
** ** [[SQLITE_CONFIG_MUTEX]]
SQLITE_CONFIG_MUTEX
**
^(This option takes a single argument which is a pointer to an ** instance of the [sqlite3_mutex_methods] structure. The argument specifies ** alternative low-level mutex routines to be used in place ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the ** content of the [sqlite3_mutex_methods] structure before the call to ** [sqlite3_config()] returns. ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** the entire mutexing subsystem is omitted from the build and hence calls to ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will ** return [SQLITE_ERROR].
** ** [[SQLITE_CONFIG_GETMUTEX]]
SQLITE_CONFIG_GETMUTEX
**
^(This option takes a single argument which is a pointer to an ** instance of the [sqlite3_mutex_methods] structure. The ** [sqlite3_mutex_methods] ** structure is filled with the currently defined mutex routines.)^ ** This option can be used to overload the default mutex allocation ** routines with a wrapper used to track mutex usage for performance ** profiling or testing, for example. ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** the entire mutexing subsystem is omitted from the build and hence calls to ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will ** return [SQLITE_ERROR].
** ** [[SQLITE_CONFIG_LOOKASIDE]]
SQLITE_CONFIG_LOOKASIDE
**
^(This option takes two arguments that determine the default ** memory allocation for the lookaside memory allocator on each ** [database connection]. The first argument is the ** size of each lookaside buffer slot and the second is the number of ** slots allocated to each database connection.)^ ^(This option sets the ** default lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] ** verb to [sqlite3_db_config()] can be used to change the lookaside ** configuration on individual connections.)^
** ** [[SQLITE_CONFIG_PCACHE2]]
SQLITE_CONFIG_PCACHE2
**
^(This option takes a single argument which is a pointer to ** an [sqlite3_pcache_methods2] object. This object specifies the interface ** to a custom page cache implementation.)^ ^SQLite makes a copy of the ** object and uses it for page cache memory allocations.
** ** [[SQLITE_CONFIG_GETPCACHE2]]
SQLITE_CONFIG_GETPCACHE2
**
^(This option takes a single argument which is a pointer to an ** [sqlite3_pcache_methods2] object. SQLite copies of the current ** page cache implementation into that object.)^
** ** [[SQLITE_CONFIG_LOG]]
SQLITE_CONFIG_LOG
**
^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a ** function with a call signature of void(*)(void*,int,const char*), ** and a pointer to void. ^If the function pointer is not NULL, it is ** invoked by [sqlite3_log()] to process each logging event. ^If the ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is ** passed through as the first parameter to the application-defined logger ** function whenever that function is invoked. ^The second parameter to ** the logger function is a copy of the first parameter to the corresponding ** [sqlite3_log()] call and is intended to be a [result code] or an ** [extended result code]. ^The third parameter passed to the logger is ** log message after formatting via [sqlite3_snprintf()]. ** The SQLite logging interface is not reentrant; the logger function ** supplied by the application must not invoke any SQLite interface. ** In a multi-threaded application, the application-defined logger ** function must be threadsafe.
** ** [[SQLITE_CONFIG_URI]]
SQLITE_CONFIG_URI **
This option takes a single argument of type int. If non-zero, then ** URI handling is globally enabled. If the parameter is zero, then URI handling ** is globally disabled. If URI handling is globally enabled, all filenames ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or ** specified as part of [ATTACH] commands are interpreted as URIs, regardless ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database ** connection is opened. If it is globally disabled, filenames are ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the ** database connection is opened. By default, URI handling is globally ** disabled. The default value may be changed by compiling with the ** [SQLITE_USE_URI] symbol defined. ** ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] **
SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE **
These options are obsolete and should not be used by new code. ** They are retained for backwards compatibility but are now no-ops. **
*/ #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ #define SQLITE_CONFIG_PCACHE 14 /* no-op */ #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ #define SQLITE_CONFIG_URI 17 /* int */ #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ /* ** CAPI3REF: Database Connection Configuration Options ** ** These constants are the available integer configuration options that ** can be passed as the second argument to the [sqlite3_db_config()] interface. ** ** New configuration options may be added in future releases of SQLite. ** Existing configuration options might be discontinued. Applications ** should check the return code from [sqlite3_db_config()] to make sure that ** the call worked. ^The [sqlite3_db_config()] interface will return a ** non-zero [error code] if a discontinued or unsupported configuration option ** is invoked. ** **
**
SQLITE_DBCONFIG_LOOKASIDE
**
^This option takes three additional arguments that determine the ** [lookaside memory allocator] configuration for the [database connection]. ** ^The first argument (the third parameter to [sqlite3_db_config()] is a ** pointer to a memory buffer to use for lookaside memory. ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb ** may be NULL in which case SQLite will allocate the ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the ** size of each lookaside buffer slot. ^The third argument is the number of ** slots. The size of the buffer in the first argument must be greater than ** or equal to the product of the second and third arguments. The buffer ** must be aligned to an 8-byte boundary. ^If the second argument to ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally ** rounded down to the next smaller multiple of 8. ^(The lookaside memory ** configuration for a database connection can only be changed when that ** connection is not currently using lookaside memory, or in other words ** when the "current value" returned by ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. ** Any attempt to change the lookaside memory configuration when lookaside ** memory is in use leaves the configuration unchanged and returns ** [SQLITE_BUSY].)^
** **
SQLITE_DBCONFIG_ENABLE_FKEY
**
^This option is used to enable or disable the enforcement of ** [foreign key constraints]. There should be two additional arguments. ** The first argument is an integer which is 0 to disable FK enforcement, ** positive to enable FK enforcement or negative to leave FK enforcement ** unchanged. The second parameter is a pointer to an integer into which ** is written 0 or 1 to indicate whether FK enforcement is off or on ** following this call. The second parameter may be a NULL pointer, in ** which case the FK enforcement setting is not reported back.
** **
SQLITE_DBCONFIG_ENABLE_TRIGGER
**
^This option is used to enable or disable [CREATE TRIGGER | triggers]. ** There should be two additional arguments. ** The first argument is an integer which is 0 to disable triggers, ** positive to enable triggers or negative to leave the setting unchanged. ** The second parameter is a pointer to an integer into which ** is written 0 or 1 to indicate whether triggers are disabled or enabled ** following this call. The second parameter may be a NULL pointer, in ** which case the trigger setting is not reported back.
** **
*/ #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ /* ** CAPI3REF: Enable Or Disable Extended Result Codes ** ** ^The sqlite3_extended_result_codes() routine enables or disables the ** [extended result codes] feature of SQLite. ^The extended result ** codes are disabled by default for historical compatibility. */ SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); /* ** CAPI3REF: Last Insert Rowid ** ** ^Each entry in an SQLite table has a unique 64-bit signed ** integer key called the [ROWID | "rowid"]. ^The rowid is always available ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those ** names are not also used by explicitly declared columns. ^If ** the table has a column of type [INTEGER PRIMARY KEY] then that column ** is another alias for the rowid. ** ** ^This routine returns the [rowid] of the most recent ** successful [INSERT] into the database from the [database connection] ** in the first argument. ^As of SQLite version 3.7.7, this routines ** records the last insert rowid of both ordinary tables and [virtual tables]. ** ^If no successful [INSERT]s ** have ever occurred on that database connection, zero is returned. ** ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] ** method, then this routine will return the [rowid] of the inserted ** row as long as the trigger or virtual table method is running. ** But once the trigger or virtual table method ends, the value returned ** by this routine reverts to what it was before the trigger or virtual ** table method began.)^ ** ** ^An [INSERT] that fails due to a constraint violation is not a ** successful [INSERT] and does not change the value returned by this ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, ** and INSERT OR ABORT make no changes to the return value of this ** routine when their insertion fails. ^(When INSERT OR REPLACE ** encounters a constraint violation, it does not fail. The ** INSERT continues to completion after deleting rows that caused ** the constraint problem so INSERT OR REPLACE will always change ** the return value of this interface.)^ ** ** ^For the purposes of this routine, an [INSERT] is considered to ** be successful even if it is subsequently rolled back. ** ** This function is accessible to SQL statements via the ** [last_insert_rowid() SQL function]. ** ** If a separate thread performs a new [INSERT] on the same ** database connection while the [sqlite3_last_insert_rowid()] ** function is running and thus changes the last insert [rowid], ** then the value returned by [sqlite3_last_insert_rowid()] is ** unpredictable and might not equal either the old or the new ** last insert [rowid]. */ SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); /* ** CAPI3REF: Count The Number Of Rows Modified ** ** ^This function returns the number of database rows that were changed ** or inserted or deleted by the most recently completed SQL statement ** on the [database connection] specified by the first parameter. ** ^(Only changes that are directly specified by the [INSERT], [UPDATE], ** or [DELETE] statement are counted. Auxiliary changes caused by ** triggers or [foreign key actions] are not counted.)^ Use the ** [sqlite3_total_changes()] function to find the total number of changes ** including changes caused by triggers and foreign key actions. ** ** ^Changes to a view that are simulated by an [INSTEAD OF trigger] ** are not counted. Only real table changes are counted. ** ** ^(A "row change" is a change to a single row of a single table ** caused by an INSERT, DELETE, or UPDATE statement. Rows that ** are changed as side effects of [REPLACE] constraint resolution, ** rollback, ABORT processing, [DROP TABLE], or by any other ** mechanisms do not count as direct row changes.)^ ** ** A "trigger context" is a scope of execution that begins and ** ends with the script of a [CREATE TRIGGER | trigger]. ** Most SQL statements are ** evaluated outside of any trigger. This is the "top level" ** trigger context. If a trigger fires from the top level, a ** new trigger context is entered for the duration of that one ** trigger. Subtriggers create subcontexts for their duration. ** ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does ** not create a new trigger context. ** ** ^This function returns the number of direct row changes in the ** most recent INSERT, UPDATE, or DELETE statement within the same ** trigger context. ** ** ^Thus, when called from the top level, this function returns the ** number of changes in the most recent INSERT, UPDATE, or DELETE ** that also occurred at the top level. ^(Within the body of a trigger, ** the sqlite3_changes() interface can be called to find the number of ** changes in the most recently completed INSERT, UPDATE, or DELETE ** statement within the body of the same trigger. ** However, the number returned does not include changes ** caused by subtriggers since those have their own context.)^ ** ** See also the [sqlite3_total_changes()] interface, the ** [count_changes pragma], and the [changes() SQL function]. ** ** If a separate thread makes changes on the same database connection ** while [sqlite3_changes()] is running then the value returned ** is unpredictable and not meaningful. */ SQLITE_API int sqlite3_changes(sqlite3*); /* ** CAPI3REF: Total Number Of Rows Modified ** ** ^This function returns the number of row changes caused by [INSERT], ** [UPDATE] or [DELETE] statements since the [database connection] was opened. ** ^(The count returned by sqlite3_total_changes() includes all changes ** from all [CREATE TRIGGER | trigger] contexts and changes made by ** [foreign key actions]. However, ** the count does not include changes used to implement [REPLACE] constraints, ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The ** count does not include rows of views that fire an [INSTEAD OF trigger], ** though if the INSTEAD OF trigger makes changes of its own, those changes ** are counted.)^ ** ^The sqlite3_total_changes() function counts the changes as soon as ** the statement that makes them is completed (when the statement handle ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). ** ** See also the [sqlite3_changes()] interface, the ** [count_changes pragma], and the [total_changes() SQL function]. ** ** If a separate thread makes changes on the same database connection ** while [sqlite3_total_changes()] is running then the value ** returned is unpredictable and not meaningful. */ SQLITE_API int sqlite3_total_changes(sqlite3*); /* ** CAPI3REF: Interrupt A Long-Running Query ** ** ^This function causes any pending database operation to abort and ** return at its earliest opportunity. This routine is typically ** called in response to a user action such as pressing "Cancel" ** or Ctrl-C where the user wants a long query operation to halt ** immediately. ** ** ^It is safe to call this routine from a thread different from the ** thread that is currently running the database operation. But it ** is not safe to call this routine with a [database connection] that ** is closed or might close before sqlite3_interrupt() returns. ** ** ^If an SQL operation is very nearly finished at the time when ** sqlite3_interrupt() is called, then it might not have an opportunity ** to be interrupted and might continue to completion. ** ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE ** that is inside an explicit transaction, then the entire transaction ** will be rolled back automatically. ** ** ^The sqlite3_interrupt(D) call is in effect until all currently running ** SQL statements on [database connection] D complete. ^Any new SQL statements ** that are started after the sqlite3_interrupt() call and before the ** running statements reaches zero are interrupted as if they had been ** running prior to the sqlite3_interrupt() call. ^New SQL statements ** that are started after the running statement count reaches zero are ** not effected by the sqlite3_interrupt(). ** ^A call to sqlite3_interrupt(D) that occurs when there are no running ** SQL statements is a no-op and has no effect on SQL statements ** that are started after the sqlite3_interrupt() call returns. ** ** If the database connection closes while [sqlite3_interrupt()] ** is running then bad things will likely happen. */ SQLITE_API void sqlite3_interrupt(sqlite3*); /* ** CAPI3REF: Determine If An SQL Statement Is Complete ** ** These routines are useful during command-line input to determine if the ** currently entered text seems to form a complete SQL statement or ** if additional input is needed before sending the text into ** SQLite for parsing. ^These routines return 1 if the input string ** appears to be a complete SQL statement. ^A statement is judged to be ** complete if it ends with a semicolon token and is not a prefix of a ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within ** string literals or quoted identifier names or comments are not ** independent tokens (they are part of the token in which they are ** embedded) and thus do not count as a statement terminator. ^Whitespace ** and comments that follow the final semicolon are ignored. ** ** ^These routines return 0 if the statement is incomplete. ^If a ** memory allocation fails, then SQLITE_NOMEM is returned. ** ** ^These routines do not parse the SQL statements thus ** will not detect syntactically incorrect SQL. ** ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked ** automatically by sqlite3_complete16(). If that initialization fails, ** then the return value from sqlite3_complete16() will be non-zero ** regardless of whether or not the input SQL is complete.)^ ** ** The input to [sqlite3_complete()] must be a zero-terminated ** UTF-8 string. ** ** The input to [sqlite3_complete16()] must be a zero-terminated ** UTF-16 string in native byte order. */ SQLITE_API int sqlite3_complete(const char *sql); SQLITE_API int sqlite3_complete16(const void *sql); /* ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors ** ** ^This routine sets a callback function that might be invoked whenever ** an attempt is made to open a database table that another thread ** or process has locked. ** ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] ** is returned immediately upon encountering the lock. ^If the busy callback ** is not NULL, then the callback might be invoked with two arguments. ** ** ^The first argument to the busy handler is a copy of the void* pointer which ** is the third argument to sqlite3_busy_handler(). ^The second argument to ** the busy handler callback is the number of times that the busy handler has ** been invoked for this locking event. ^If the ** busy callback returns 0, then no additional attempts are made to ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. ** ^If the callback returns non-zero, then another attempt ** is made to open the database for reading and the cycle repeats. ** ** The presence of a busy handler does not guarantee that it will be invoked ** when there is lock contention. ^If SQLite determines that invoking the busy ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. ** Consider a scenario where one process is holding a read lock that ** it is trying to promote to a reserved lock and ** a second process is holding a reserved lock that it is trying ** to promote to an exclusive lock. The first process cannot proceed ** because it is blocked by the second and the second process cannot ** proceed because it is blocked by the first. If both processes ** invoke the busy handlers, neither will make any progress. Therefore, ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this ** will induce the first process to release its read lock and allow ** the second process to proceed. ** ** ^The default busy callback is NULL. ** ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] ** when SQLite is in the middle of a large transaction where all the ** changes will not fit into the in-memory cache. SQLite will ** already hold a RESERVED lock on the database file, but it needs ** to promote this lock to EXCLUSIVE so that it can spill cache ** pages into the database file without harm to concurrent ** readers. ^If it is unable to promote the lock, then the in-memory ** cache will be left in an inconsistent state and so the error ** code is promoted from the relatively benign [SQLITE_BUSY] to ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion ** forces an automatic rollback of the changes. See the ** ** CorruptionFollowingBusyError wiki page for a discussion of why ** this is important. ** ** ^(There can only be a single busy handler defined for each ** [database connection]. Setting a new busy handler clears any ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] ** will also set or clear the busy handler. ** ** The busy callback should not take any actions which modify the ** database connection that invoked the busy handler. Any such actions ** result in undefined behavior. ** ** A busy handler must not close the database connection ** or [prepared statement] that invoked the busy handler. */ SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); /* ** CAPI3REF: Set A Busy Timeout ** ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps ** for a specified amount of time when a table is locked. ^The handler ** will sleep multiple times until at least "ms" milliseconds of sleeping ** have accumulated. ^After at least "ms" milliseconds of sleeping, ** the handler returns 0 which causes [sqlite3_step()] to return ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. ** ** ^Calling this routine with an argument less than or equal to zero ** turns off all busy handlers. ** ** ^(There can only be a single busy handler for a particular ** [database connection] any any given moment. If another busy handler ** was defined (using [sqlite3_busy_handler()]) prior to calling ** this routine, that other busy handler is cleared.)^ */ SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); /* ** CAPI3REF: Convenience Routines For Running Queries ** ** This is a legacy interface that is preserved for backwards compatibility. ** Use of this interface is not recommended. ** ** Definition: A result table is memory data structure created by the ** [sqlite3_get_table()] interface. A result table records the ** complete query results from one or more queries. ** ** The table conceptually has a number of rows and columns. But ** these numbers are not part of the result table itself. These ** numbers are obtained separately. Let N be the number of rows ** and M be the number of columns. ** ** A result table is an array of pointers to zero-terminated UTF-8 strings. ** There are (N+1)*M elements in the array. The first M pointers point ** to zero-terminated strings that contain the names of the columns. ** The remaining entries all point to query results. NULL values result ** in NULL pointers. All other values are in their UTF-8 zero-terminated ** string representation as returned by [sqlite3_column_text()]. ** ** A result table might consist of one or more memory allocations. ** It is not safe to pass a result table directly to [sqlite3_free()]. ** A result table should be deallocated using [sqlite3_free_table()]. ** ** ^(As an example of the result table format, suppose a query result ** is as follows: ** ** 
**        Name        | Age
**        -----------------------
**        Alice       | 43
**        Bob         | 28
**        Cindy       | 21
**
** ** There are two column (M==2) and three rows (N==3). Thus the ** result table has 8 entries. Suppose the result table is stored ** in an array names azResult. Then azResult holds this content: ** ** 
**        azResult[0] = "Name";
**        azResult[1] = "Age";
**        azResult[2] = "Alice";
**        azResult[3] = "43";
**        azResult[4] = "Bob";
**        azResult[5] = "28";
**        azResult[6] = "Cindy";
**        azResult[7] = "21";
**
)^ ** ** ^The sqlite3_get_table() function evaluates one or more ** semicolon-separated SQL statements in the zero-terminated UTF-8 ** string of its 2nd parameter and returns a result table to the ** pointer given in its 3rd parameter. ** ** After the application has finished with the result from sqlite3_get_table(), ** it must pass the result table pointer to sqlite3_free_table() in order to ** release the memory that was malloced. Because of the way the ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling ** function must not try to call [sqlite3_free()] directly. Only ** [sqlite3_free_table()] is able to release the memory properly and safely. ** ** The sqlite3_get_table() interface is implemented as a wrapper around ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access ** to any internal data structures of SQLite. It uses only the public ** interface defined here. As a consequence, errors that occur in the ** wrapper layer outside of the internal [sqlite3_exec()] call are not ** reflected in subsequent calls to [sqlite3_errcode()] or ** [sqlite3_errmsg()]. */ SQLITE_API int sqlite3_get_table( sqlite3 *db, /* An open database */ const char *zSql, /* SQL to be evaluated */ char ***pazResult, /* Results of the query */ int *pnRow, /* Number of result rows written here */ int *pnColumn, /* Number of result columns written here */ char **pzErrmsg /* Error msg written here */ ); SQLITE_API void sqlite3_free_table(char **result); /* ** CAPI3REF: Formatted String Printing Functions ** ** These routines are work-alikes of the "printf()" family of functions ** from the standard C library. ** ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their ** results into memory obtained from [sqlite3_malloc()]. ** The strings returned by these two routines should be ** released by [sqlite3_free()]. ^Both routines return a ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough ** memory to hold the resulting string. ** ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from ** the standard C library. The result is written into the ** buffer supplied as the second parameter whose size is given by ** the first parameter. Note that the order of the ** first two parameters is reversed from snprintf().)^ This is an ** historical accident that cannot be fixed without breaking ** backwards compatibility. ^(Note also that sqlite3_snprintf() ** returns a pointer to its buffer instead of the number of ** characters actually written into the buffer.)^ We admit that ** the number of characters written would be a more useful return ** value but we cannot change the implementation of sqlite3_snprintf() ** now without breaking compatibility. ** ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() ** guarantees that the buffer is always zero-terminated. ^The first ** parameter "n" is the total size of the buffer, including space for ** the zero terminator. So the longest string that can be completely ** written will be n-1 characters. ** ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). ** ** These routines all implement some additional formatting ** options that are useful for constructing SQL statements. ** All of the usual printf() formatting options apply. In addition, there ** is are "%q", "%Q", and "%z" options. ** ** ^(The %q option works like %s in that it substitutes a nul-terminated ** string from the argument list. But %q also doubles every '\'' character. ** %q is designed for use inside a string literal.)^ By doubling each '\'' ** character it escapes that character and allows it to be inserted into ** the string. ** ** For example, assume the string variable zText contains text as follows: ** ** 
**  char *zText = "It's a happy day!";
**
** ** One can use this text in an SQL statement as follows: ** ** 
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
**  sqlite3_exec(db, zSQL, 0, 0, 0);
**  sqlite3_free(zSQL);
**
** ** Because the %q format string is used, the '\'' character in zText ** is escaped and the SQL generated is as follows: ** ** 
**  INSERT INTO table1 VALUES('It''s a happy day!')
**
** ** This is correct. Had we used %s instead of %q, the generated SQL ** would have looked like this: ** ** 
**  INSERT INTO table1 VALUES('It's a happy day!');
**
** ** This second example is an SQL syntax error. As a general rule you should ** always use %q instead of %s when inserting text into a string literal. ** ** ^(The %Q option works like %q except it also adds single quotes around ** the outside of the total string. Additionally, if the parameter in the ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without ** single quotes).)^ So, for example, one could say: ** ** 
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
**  sqlite3_exec(db, zSQL, 0, 0, 0);
**  sqlite3_free(zSQL);
**
** ** The code above will render a correct SQL statement in the zSQL ** variable even if the zText variable is a NULL pointer. ** ** ^(The "%z" formatting option works like "%s" but with the ** addition that after the string has been read and copied into ** the result, [sqlite3_free()] is called on the input string.)^ */ SQLITE_API char *sqlite3_mprintf(const char*,...); SQLITE_API char *sqlite3_vmprintf(const char*, va_list); SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); /* ** CAPI3REF: Memory Allocation Subsystem ** ** The SQLite core uses these three routines for all of its own ** internal memory allocation needs. "Core" in the previous sentence ** does not include operating-system specific VFS implementation. The ** Windows VFS uses native malloc() and free() for some operations. ** ** ^The sqlite3_malloc() routine returns a pointer to a block ** of memory at least N bytes in length, where N is the parameter. ** ^If sqlite3_malloc() is unable to obtain sufficient free ** memory, it returns a NULL pointer. ^If the parameter N to ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns ** a NULL pointer. ** ** ^Calling sqlite3_free() with a pointer previously returned ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so ** that it might be reused. ^The sqlite3_free() routine is ** a no-op if is called with a NULL pointer. Passing a NULL pointer ** to sqlite3_free() is harmless. After being freed, memory ** should neither be read nor written. Even reading previously freed ** memory might result in a segmentation fault or other severe error. ** Memory corruption, a segmentation fault, or other severe error ** might result if sqlite3_free() is called with a non-NULL pointer that ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). ** ** ^(The sqlite3_realloc() interface attempts to resize a ** prior memory allocation to be at least N bytes, where N is the ** second parameter. The memory allocation to be resized is the first ** parameter.)^ ^ If the first parameter to sqlite3_realloc() ** is a NULL pointer then its behavior is identical to calling ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). ** ^If the second parameter to sqlite3_realloc() is zero or ** negative then the behavior is exactly the same as calling ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). ** ^sqlite3_realloc() returns a pointer to a memory allocation ** of at least N bytes in size or NULL if sufficient memory is unavailable. ** ^If M is the size of the prior allocation, then min(N,M) bytes ** of the prior allocation are copied into the beginning of buffer returned ** by sqlite3_realloc() and the prior allocation is freed. ** ^If sqlite3_realloc() returns NULL, then the prior allocation ** is not freed. ** ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() ** is always aligned to at least an 8 byte boundary, or to a ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time ** option is used. ** ** In SQLite version 3.5.0 and 3.5.1, it was possible to define ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in ** implementation of these routines to be omitted. That capability ** is no longer provided. Only built-in memory allocators can be used. ** ** The Windows OS interface layer calls ** the system malloc() and free() directly when converting ** filenames between the UTF-8 encoding used by SQLite ** and whatever filename encoding is used by the particular Windows ** installation. Memory allocation errors are detected, but ** they are reported back as [SQLITE_CANTOPEN] or ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. ** ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] ** must be either NULL or else pointers obtained from a prior ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have ** not yet been released. ** ** The application must not read or write any part of ** a block of memory after it has been released using ** [sqlite3_free()] or [sqlite3_realloc()]. */ SQLITE_API void *sqlite3_malloc(int); SQLITE_API void *sqlite3_realloc(void*, int); SQLITE_API void sqlite3_free(void*); /* ** CAPI3REF: Memory Allocator Statistics ** ** SQLite provides these two interfaces for reporting on the status ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] ** routines, which form the built-in memory allocation subsystem. ** ** ^The [sqlite3_memory_used()] routine returns the number of bytes ** of memory currently outstanding (malloced but not freed). ** ^The [sqlite3_memory_highwater()] routine returns the maximum ** value of [sqlite3_memory_used()] since the high-water mark ** was last reset. ^The values returned by [sqlite3_memory_used()] and ** [sqlite3_memory_highwater()] include any overhead ** added by SQLite in its implementation of [sqlite3_malloc()], ** but not overhead added by the any underlying system library ** routines that [sqlite3_malloc()] may call. ** ** ^The memory high-water mark is reset to the current value of ** [sqlite3_memory_used()] if and only if the parameter to ** [sqlite3_memory_highwater()] is true. ^The value returned ** by [sqlite3_memory_highwater(1)] is the high-water mark ** prior to the reset. */ SQLITE_API sqlite3_int64 sqlite3_memory_used(void); SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); /* ** CAPI3REF: Pseudo-Random Number Generator ** ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to ** select random [ROWID | ROWIDs] when inserting new records into a table that ** already uses the largest possible [ROWID]. The PRNG is also used for ** the build-in random() and randomblob() SQL functions. This interface allows ** applications to access the same PRNG for other purposes. ** ** ^A call to this routine stores N bytes of randomness into buffer P. ** ** ^The first time this routine is invoked (either internally or by ** the application) the PRNG is seeded using randomness obtained ** from the xRandomness method of the default [sqlite3_vfs] object. ** ^On all subsequent invocations, the pseudo-randomness is generated ** internally and without recourse to the [sqlite3_vfs] xRandomness ** method. */ SQLITE_API void sqlite3_randomness(int N, void *P); /* ** CAPI3REF: Compile-Time Authorization Callbacks ** ** ^This routine registers an authorizer callback with a particular ** [database connection], supplied in the first argument. ** ^The authorizer callback is invoked as SQL statements are being compiled ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various ** points during the compilation process, as logic is being created ** to perform various actions, the authorizer callback is invoked to ** see if those actions are allowed. ^The authorizer callback should ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the ** specific action but allow the SQL statement to continue to be ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be ** rejected with an error. ^If the authorizer callback returns ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] ** then the [sqlite3_prepare_v2()] or equivalent call that triggered ** the authorizer will fail with an error message. ** ** When the callback returns [SQLITE_OK], that means the operation ** requested is ok. ^When the callback returns [SQLITE_DENY], the ** [sqlite3_prepare_v2()] or equivalent call that triggered the ** authorizer will fail with an error message explaining that ** access is denied. ** ** ^The first parameter to the authorizer callback is a copy of the third ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter ** to the callback is an integer [SQLITE_COPY | action code] that specifies ** the particular action to be authorized. ^The third through sixth parameters ** to the callback are zero-terminated strings that contain additional ** details about the action to be authorized. ** ** ^If the action code is [SQLITE_READ] ** and the callback returns [SQLITE_IGNORE] then the ** [prepared statement] statement is constructed to substitute ** a NULL value in place of the table column that would have ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] ** return can be used to deny an untrusted user access to individual ** columns of a table. ** ^If the action code is [SQLITE_DELETE] and the callback returns ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the ** [truncate optimization] is disabled and all rows are deleted individually. ** ** An authorizer is used when [sqlite3_prepare | preparing] ** SQL statements from an untrusted source, to ensure that the SQL statements ** do not try to access data they are not allowed to see, or that they do not ** try to execute malicious statements that damage the database. For ** example, an application may allow a user to enter arbitrary ** SQL queries for evaluation by a database. But the application does ** not want the user to be able to make arbitrary changes to the ** database. An authorizer could then be put in place while the ** user-entered SQL is being [sqlite3_prepare | prepared] that ** disallows everything except [SELECT] statements. ** ** Applications that need to process SQL from untrusted sources ** might also consider lowering resource limits using [sqlite3_limit()] ** and limiting database size using the [max_page_count] [PRAGMA] ** in addition to using an authorizer. ** ** ^(Only a single authorizer can be in place on a database connection ** at a time. Each call to sqlite3_set_authorizer overrides the ** previous call.)^ ^Disable the authorizer by installing a NULL callback. ** The authorizer is disabled by default. ** ** The authorizer callback must not do anything that will modify ** the database connection that invoked the authorizer callback. ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their ** database connections for the meaning of "modify" in this paragraph. ** ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the ** statement might be re-prepared during [sqlite3_step()] due to a ** schema change. Hence, the application should ensure that the ** correct authorizer callback remains in place during the [sqlite3_step()]. ** ** ^Note that the authorizer callback is invoked only during ** [sqlite3_prepare()] or its variants. Authorization is not ** performed during statement evaluation in [sqlite3_step()], unless ** as stated in the previous paragraph, sqlite3_step() invokes ** sqlite3_prepare_v2() to reprepare a statement after a schema change. */ SQLITE_API int sqlite3_set_authorizer( sqlite3*, int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), void *pUserData ); /* ** CAPI3REF: Authorizer Return Codes ** ** The [sqlite3_set_authorizer | authorizer callback function] must ** return either [SQLITE_OK] or one of these two constants in order ** to signal SQLite whether or not the action is permitted. See the ** [sqlite3_set_authorizer | authorizer documentation] for additional ** information. ** ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] ** from the [sqlite3_vtab_on_conflict()] interface. */ #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ /* ** CAPI3REF: Authorizer Action Codes ** ** The [sqlite3_set_authorizer()] interface registers a callback function ** that is invoked to authorize certain SQL statement actions. The ** second parameter to the callback is an integer code that specifies ** what action is being authorized. These are the integer action codes that ** the authorizer callback may be passed. ** ** These action code values signify what kind of operation is to be ** authorized. The 3rd and 4th parameters to the authorization ** callback function will be parameters or NULL depending on which of these ** codes is used as the second parameter. ^(The 5th parameter to the ** authorizer callback is the name of the database ("main", "temp", ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback ** is the name of the inner-most trigger or view that is responsible for ** the access attempt or NULL if this access attempt is directly from ** top-level SQL code. */ /******************************************* 3rd ************ 4th ***********/ #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ #define SQLITE_DELETE 9 /* Table Name NULL */ #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ #define SQLITE_DROP_VIEW 17 /* View Name NULL */ #define SQLITE_INSERT 18 /* Table Name NULL */ #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ #define SQLITE_READ 20 /* Table Name Column Name */ #define SQLITE_SELECT 21 /* NULL NULL */ #define SQLITE_TRANSACTION 22 /* Operation NULL */ #define SQLITE_UPDATE 23 /* Table Name Column Name */ #define SQLITE_ATTACH 24 /* Filename NULL */ #define SQLITE_DETACH 25 /* Database Name NULL */ #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ #define SQLITE_REINDEX 27 /* Index Name NULL */ #define SQLITE_ANALYZE 28 /* Table Name NULL */ #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ #define SQLITE_FUNCTION 31 /* NULL Function Name */ #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ #define SQLITE_COPY 0 /* No longer used */ /* ** CAPI3REF: Tracing And Profiling Functions ** ** These routines register callback functions that can be used for ** tracing and profiling the execution of SQL statements. ** ** ^The callback function registered by sqlite3_trace() is invoked at ** various times when an SQL statement is being run by [sqlite3_step()]. ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the ** SQL statement text as the statement first begins executing. ** ^(Additional sqlite3_trace() callbacks might occur ** as each triggered subprogram is entered. The callbacks for triggers ** contain a UTF-8 SQL comment that identifies the trigger.)^ ** ** ^The callback function registered by sqlite3_profile() is invoked ** as each SQL statement finishes. ^The profile callback contains ** the original statement text and an estimate of wall-clock time ** of how long that statement took to run. ^The profile callback ** time is in units of nanoseconds, however the current implementation ** is only capable of millisecond resolution so the six least significant ** digits in the time are meaningless. Future versions of SQLite ** might provide greater resolution on the profiler callback. The ** sqlite3_profile() function is considered experimental and is ** subject to change in future versions of SQLite. */ SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, void(*xProfile)(void*,const char*,sqlite3_uint64), void*); /* ** CAPI3REF: Query Progress Callbacks ** ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback ** function X to be invoked periodically during long running calls to ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for ** database connection D. An example use for this ** interface is to keep a GUI updated during a large query. ** ** ^The parameter P is passed through as the only parameter to the ** callback function X. ^The parameter N is the number of ** [virtual machine instructions] that are evaluated between successive ** invocations of the callback X. ** ** ^Only a single progress handler may be defined at one time per ** [database connection]; setting a new progress handler cancels the ** old one. ^Setting parameter X to NULL disables the progress handler. ** ^The progress handler is also disabled by setting N to a value less ** than 1. ** ** ^If the progress callback returns non-zero, the operation is ** interrupted. This feature can be used to implement a ** "Cancel" button on a GUI progress dialog box. ** ** The progress handler callback must not do anything that will modify ** the database connection that invoked the progress handler. ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their ** database connections for the meaning of "modify" in this paragraph. ** */ SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); /* ** CAPI3REF: Opening A New Database Connection ** ** ^These routines open an SQLite database file as specified by the ** filename argument. ^The filename argument is interpreted as UTF-8 for ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte ** order for sqlite3_open16(). ^(A [database connection] handle is usually ** returned in *ppDb, even if an error occurs. The only exception is that ** if SQLite is unable to allocate memory to hold the [sqlite3] object, ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] ** object.)^ ^(If the database is opened (and/or created) successfully, then ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain ** an English language description of the error following a failure of any ** of the sqlite3_open() routines. ** ** ^The default encoding for the database will be UTF-8 if ** sqlite3_open() or sqlite3_open_v2() is called and ** UTF-16 in the native byte order if sqlite3_open16() is used. ** ** Whether or not an error occurs when it is opened, resources ** associated with the [database connection] handle should be released by ** passing it to [sqlite3_close()] when it is no longer required. ** ** The sqlite3_open_v2() interface works like sqlite3_open() ** except that it accepts two additional parameters for additional control ** over the new database connection. ^(The flags parameter to ** sqlite3_open_v2() can take one of ** the following three values, optionally combined with the ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ ** **
** ^(
[SQLITE_OPEN_READONLY]
**
The database is opened in read-only mode. If the database does not ** already exist, an error is returned.
)^ ** ** ^(
[SQLITE_OPEN_READWRITE]
**
The database is opened for reading and writing if possible, or reading ** only if the file is write protected by the operating system. In either ** case the database must already exist, otherwise an error is returned.
)^ ** ** ^(
[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]
**
The database is opened for reading and writing, and is created if ** it does not already exist. This is the behavior that is always used for ** sqlite3_open() and sqlite3_open16().
)^ **
** ** If the 3rd parameter to sqlite3_open_v2() is not one of the ** combinations shown above optionally combined with other ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] ** then the behavior is undefined. ** ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection ** opens in the multi-thread [threading mode] as long as the single-thread ** mode has not been set at compile-time or start-time. ^If the ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens ** in the serialized [threading mode] unless single-thread was ** previously selected at compile-time or start-time. ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be ** eligible to use [shared cache mode], regardless of whether or not shared ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not ** participate in [shared cache mode] even if it is enabled. ** ** ^The fourth parameter to sqlite3_open_v2() is the name of the ** [sqlite3_vfs] object that defines the operating system interface that ** the new database connection should use. ^If the fourth parameter is ** a NULL pointer then the default [sqlite3_vfs] object is used. ** ** ^If the filename is ":memory:", then a private, temporary in-memory database ** is created for the connection. ^This in-memory database will vanish when ** the database connection is closed. Future versions of SQLite might ** make use of additional special filenames that begin with the ":" character. ** It is recommended that when a database filename actually does begin with ** a ":" character you should prefix the filename with a pathname such as ** "./" to avoid ambiguity. ** ** ^If the filename is an empty string, then a private, temporary ** on-disk database will be created. ^This private database will be ** automatically deleted as soon as the database connection is closed. ** ** [[URI filenames in sqlite3_open()]]

URI Filenames

** ** ^If [URI filename] interpretation is enabled, and the filename argument ** begins with "file:", then the filename is interpreted as a URI. ^URI ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is ** set in the fourth argument to sqlite3_open_v2(), or if it has ** been enabled globally using the [SQLITE_CONFIG_URI] option with the ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. ** As of SQLite version 3.7.7, URI filename interpretation is turned off ** by default, but future releases of SQLite might enable URI filename ** interpretation by default. See "[URI filenames]" for additional ** information. ** ** URI filenames are parsed according to RFC 3986. ^If the URI contains an ** authority, then it must be either an empty string or the string ** "localhost". ^If the authority is not an empty string or "localhost", an ** error is returned to the caller. ^The fragment component of a URI, if ** present, is ignored. ** ** ^SQLite uses the path component of the URI as the name of the disk file ** which contains the database. ^If the path begins with a '/' character, ** then it is interpreted as an absolute path. ^If the path does not begin ** with a '/' (meaning that the authority section is omitted from the URI) ** then the path is interpreted as a relative path. ** ^On windows, the first component of an absolute path ** is a drive specification (e.g. "C:"). ** ** [[core URI query parameters]] ** The query component of a URI may contain parameters that are interpreted ** either by SQLite itself, or by a [VFS | custom VFS implementation]. ** SQLite interprets the following three query parameters: ** **
    **
  • vfs: ^The "vfs" parameter may be used to specify the name of ** a VFS object that provides the operating system interface that should ** be used to access the database file on disk. ^If this option is set to ** an empty string the default VFS object is used. ^Specifying an unknown ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is ** present, then the VFS specified by the option takes precedence over ** the value passed as the fourth parameter to sqlite3_open_v2(). ** **
  • mode: ^(The mode parameter may be set to either "ro", "rw" or ** "rwc". Attempting to set it to any other value is an error)^. ** ^If "ro" is specified, then the database is opened for read-only ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the ** third argument to sqlite3_prepare_v2(). ^If the mode option is set to ** "rw", then the database is opened for read-write (but not create) ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had ** been set. ^Value "rwc" is equivalent to setting both ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is ** used, it is an error to specify a value for the mode parameter that is ** less restrictive than that specified by the flags passed as the third ** parameter. ** **
  • cache: ^The cache parameter may be set to either "shared" or ** "private". ^Setting it to "shared" is equivalent to setting the ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in ** a URI filename, its value overrides any behaviour requested by setting ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. **
** ** ^Specifying an unknown parameter in the query component of a URI is not an ** error. Future versions of SQLite might understand additional query ** parameters. See "[query parameters with special meaning to SQLite]" for ** additional information. ** ** [[URI filename examples]]

URI filename examples

** ** **
URI filenames Results **
file:data.db ** Open the file "data.db" in the current directory. **
file:/home/fred/data.db
** file:///home/fred/data.db
** file://localhost/home/fred/data.db
** Open the database file "/home/fred/data.db". **
file://darkstar/home/fred/data.db ** An error. "darkstar" is not a recognized authority. **
** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db ** Windows only: Open the file "data.db" on fred's desktop on drive ** C:. Note that the %20 escaping in this example is not strictly ** necessary - space characters can be used literally ** in URI filenames. **
file:data.db?mode=ro&cache=private ** Open file "data.db" in the current directory for read-only access. ** Regardless of whether or not shared-cache mode is enabled by ** default, use a private cache. **
file:/home/fred/data.db?vfs=unix-nolock ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". **
file:data.db?mode=readonly ** An error. "readonly" is not a valid option for the "mode" parameter. **
** ** ^URI hexadecimal escape sequences (%HH) are supported within the path and ** query components of a URI. A hexadecimal escape sequence consists of a ** percent sign - "%" - followed by exactly two hexadecimal digits ** specifying an octet value. ^Before the path or query components of a ** URI filename are interpreted, they are encoded using UTF-8 and all ** hexadecimal escape sequences replaced by a single byte containing the ** corresponding octet. If this process generates an invalid UTF-8 encoding, ** the results are undefined. ** ** Note to Windows users: The encoding used for the filename argument ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever ** codepage is currently defined. Filenames containing international ** characters must be converted to UTF-8 prior to passing them into ** sqlite3_open() or sqlite3_open_v2(). */ SQLITE_API int sqlite3_open( const char *filename, /* Database filename (UTF-8) */ sqlite3 **ppDb /* OUT: SQLite db handle */ ); SQLITE_API int sqlite3_open16( const void *filename, /* Database filename (UTF-16) */ sqlite3 **ppDb /* OUT: SQLite db handle */ ); SQLITE_API int sqlite3_open_v2( const char *filename, /* Database filename (UTF-8) */ sqlite3 **ppDb, /* OUT: SQLite db handle */ int flags, /* Flags */ const char *zVfs /* Name of VFS module to use */ ); /* ** CAPI3REF: Obtain Values For URI Parameters ** ** These are utility routines, useful to VFS implementations, that check ** to see if a database file was a URI that contained a specific query ** parameter, and if so obtains the value of that query parameter. ** ** If F is the database filename pointer passed into the xOpen() method of ** a VFS implementation when the flags parameter to xOpen() has one or ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and ** P is the name of the query parameter, then ** sqlite3_uri_parameter(F,P) returns the value of the P ** parameter if it exists or a NULL pointer if P does not appear as a ** query parameter on F. If P is a query parameter of F ** has no explicit value, then sqlite3_uri_parameter(F,P) returns ** a pointer to an empty string. ** ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean ** parameter and returns true (1) or false (0) according to the value ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the ** value of query parameter P is one of "yes", "true", or "on" in any ** case or if the value begins with a non-zero number. The ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of ** query parameter P is one of "no", "false", or "off" in any case or ** if the value begins with a numeric zero. If P is not a query ** parameter on F or if the value of P is does not match any of the ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). ** ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a ** 64-bit signed integer and returns that integer, or D if P does not ** exist. If the value of P is something other than an integer, then ** zero is returned. ** ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and ** is not a database file pathname pointer that SQLite passed into the xOpen ** VFS method, then the behavior of this routine is undefined and probably ** undesirable. */ SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); /* ** CAPI3REF: Error Codes And Messages ** ** ^The sqlite3_errcode() interface returns the numeric [result code] or ** [extended result code] for the most recent failed sqlite3_* API call ** associated with a [database connection]. If a prior API call failed ** but the most recent API call succeeded, the return value from ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() ** interface is the same except that it always returns the ** [extended result code] even when extended result codes are ** disabled. ** ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language ** text that describes the error, as either UTF-8 or UTF-16 respectively. ** ^(Memory to hold the error message string is managed internally. ** The application does not need to worry about freeing the result. ** However, the error string might be overwritten or deallocated by ** subsequent calls to other SQLite interface functions.)^ ** ** When the serialized [threading mode] is in use, it might be the ** case that a second error occurs on a separate thread in between ** the time of the first error and the call to these interfaces. ** When that happens, the second error will be reported since these ** interfaces always report the most recent result. To avoid ** this, each thread can obtain exclusive use of the [database connection] D ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after ** all calls to the interfaces listed here are completed. ** ** If an interface fails with SQLITE_MISUSE, that means the interface ** was invoked incorrectly by the application. In that case, the ** error code and message may or may not be set. */ SQLITE_API int sqlite3_errcode(sqlite3 *db); SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); SQLITE_API const char *sqlite3_errmsg(sqlite3*); SQLITE_API const void *sqlite3_errmsg16(sqlite3*); /* ** CAPI3REF: SQL Statement Object ** KEYWORDS: {prepared statement} {prepared statements} ** ** An instance of this object represents a single SQL statement. ** This object is variously known as a "prepared statement" or a ** "compiled SQL statement" or simply as a "statement". ** ** The life of a statement object goes something like this: ** **
    **
  1. Create the object using [sqlite3_prepare_v2()] or a related ** function. **
  2. Bind values to [host parameters] using the sqlite3_bind_*() ** interfaces. **
  3. Run the SQL by calling [sqlite3_step()] one or more times. **
  4. Reset the statement using [sqlite3_reset()] then go back ** to step 2. Do this zero or more times. **
  5. Destroy the object using [sqlite3_finalize()]. **
** ** Refer to documentation on individual methods above for additional ** information. */ typedef struct sqlite3_stmt sqlite3_stmt; /* ** CAPI3REF: Run-time Limits ** ** ^(This interface allows the size of various constructs to be limited ** on a connection by connection basis. The first parameter is the ** [database connection] whose limit is to be set or queried. The ** second parameter is one of the [limit categories] that define a ** class of constructs to be size limited. The third parameter is the ** new limit for that construct.)^ ** ** ^If the new limit is a negative number, the limit is unchanged. ** ^(For each limit category SQLITE_LIMIT_NAME there is a ** [limits | hard upper bound] ** set at compile-time by a C preprocessor macro called ** [limits | SQLITE_MAX_NAME]. ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ ** ^Attempts to increase a limit above its hard upper bound are ** silently truncated to the hard upper bound. ** ** ^Regardless of whether or not the limit was changed, the ** [sqlite3_limit()] interface returns the prior value of the limit. ** ^Hence, to find the current value of a limit without changing it, ** simply invoke this interface with the third parameter set to -1. ** ** Run-time limits are intended for use in applications that manage ** both their own internal database and also databases that are controlled ** by untrusted external sources. An example application might be a ** web browser that has its own databases for storing history and ** separate databases controlled by JavaScript applications downloaded ** off the Internet. The internal databases can be given the ** large, default limits. Databases managed by external sources can ** be given much smaller limits designed to prevent a denial of service ** attack. Developers might also want to use the [sqlite3_set_authorizer()] ** interface to further control untrusted SQL. The size of the database ** created by an untrusted script can be contained using the ** [max_page_count] [PRAGMA]. ** ** New run-time limit categories may be added in future releases. */ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); /* ** CAPI3REF: Run-Time Limit Categories ** KEYWORDS: {limit category} {*limit categories} ** ** These constants define various performance limits ** that can be lowered at run-time using [sqlite3_limit()]. ** The synopsis of the meanings of the various limits is shown below. ** Additional information is available at [limits | Limits in SQLite]. ** **
** [[SQLITE_LIMIT_LENGTH]] ^(
SQLITE_LIMIT_LENGTH
**
The maximum size of any string or BLOB or table row, in bytes.
)^ ** ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(
SQLITE_LIMIT_SQL_LENGTH
**
The maximum length of an SQL statement, in bytes.
)^ ** ** [[SQLITE_LIMIT_COLUMN]] ^(
SQLITE_LIMIT_COLUMN
**
The maximum number of columns in a table definition or in the ** result set of a [SELECT] or the maximum number of columns in an index ** or in an ORDER BY or GROUP BY clause.
)^ ** ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(
SQLITE_LIMIT_EXPR_DEPTH
**
The maximum depth of the parse tree on any expression.
)^ ** ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(
SQLITE_LIMIT_COMPOUND_SELECT
**
The maximum number of terms in a compound SELECT statement.
)^ ** ** [[SQLITE_LIMIT_VDBE_OP]] ^(
SQLITE_LIMIT_VDBE_OP
**
The maximum number of instructions in a virtual machine program ** used to implement an SQL statement. This limit is not currently ** enforced, though that might be added in some future release of ** SQLite.
)^ ** ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(
SQLITE_LIMIT_FUNCTION_ARG
**
The maximum number of arguments on a function.
)^ ** ** [[SQLITE_LIMIT_ATTACHED]] ^(
SQLITE_LIMIT_ATTACHED
**
The maximum number of [ATTACH | attached databases].)^
** ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] ** ^(
SQLITE_LIMIT_LIKE_PATTERN_LENGTH
**
The maximum length of the pattern argument to the [LIKE] or ** [GLOB] operators.
)^ ** ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] ** ^(
SQLITE_LIMIT_VARIABLE_NUMBER
**
The maximum index number of any [parameter] in an SQL statement.)^ ** ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(
SQLITE_LIMIT_TRIGGER_DEPTH
**
The maximum depth of recursion for triggers.
)^ **
*/ #define SQLITE_LIMIT_LENGTH 0 #define SQLITE_LIMIT_SQL_LENGTH 1 #define SQLITE_LIMIT_COLUMN 2 #define SQLITE_LIMIT_EXPR_DEPTH 3 #define SQLITE_LIMIT_COMPOUND_SELECT 4 #define SQLITE_LIMIT_VDBE_OP 5 #define SQLITE_LIMIT_FUNCTION_ARG 6 #define SQLITE_LIMIT_ATTACHED 7 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 /* ** CAPI3REF: Compiling An SQL Statement ** KEYWORDS: {SQL statement compiler} ** ** To execute an SQL query, it must first be compiled into a byte-code ** program using one of these routines. ** ** The first argument, "db", is a [database connection] obtained from a ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or ** [sqlite3_open16()]. The database connection must not have been closed. ** ** The second argument, "zSql", is the statement to be compiled, encoded ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() ** use UTF-16. ** ** ^If the nByte argument is less than zero, then zSql is read up to the ** first zero terminator. ^If nByte is non-negative, then it is the maximum ** number of bytes read from zSql. ^When nByte is non-negative, the ** zSql string ends at either the first '\000' or '\u0000' character or ** the nByte-th byte, whichever comes first. If the caller knows ** that the supplied string is nul-terminated, then there is a small ** performance advantage to be gained by passing an nByte parameter that ** is equal to the number of bytes in the input string including ** the nul-terminator bytes as this saves SQLite from having to ** make a copy of the input string. ** ** ^If pzTail is not NULL then *pzTail is made to point to the first byte ** past the end of the first SQL statement in zSql. These routines only ** compile the first statement in zSql, so *pzTail is left pointing to ** what remains uncompiled. ** ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set ** to NULL. ^If the input text contains no SQL (if the input is an empty ** string or a comment) then *ppStmt is set to NULL. ** The calling procedure is responsible for deleting the compiled ** SQL statement using [sqlite3_finalize()] after it has finished with it. ** ppStmt may not be NULL. ** ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; ** otherwise an [error code] is returned. ** ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are ** recommended for all new programs. The two older interfaces are retained ** for backwards compatibility, but their use is discouraged. ** ^In the "v2" interfaces, the prepared statement ** that is returned (the [sqlite3_stmt] object) contains a copy of the ** original SQL text. This causes the [sqlite3_step()] interface to ** behave differently in three ways: ** **
    **
  1. ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it ** always used to do, [sqlite3_step()] will automatically recompile the SQL ** statement and try to run it again. **
    2. ** **
  2. ** ^When an error occurs, [sqlite3_step()] will return one of the detailed ** [error codes] or [extended error codes]. ^The legacy behavior was that ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code ** and the application would have to make a second call to [sqlite3_reset()] ** in order to find the underlying cause of the problem. With the "v2" prepare ** interfaces, the underlying reason for the error is returned immediately. **
    3. ** **
  3. ** ^If the specific value bound to [parameter | host parameter] in the ** WHERE clause might influence the choice of query plan for a statement, ** then the statement will be automatically recompiled, as if there had been ** a schema change, on the first [sqlite3_step()] call following any change ** to the [sqlite3_bind_text | bindings] of that [parameter]. ** ^The specific value of WHERE-clause [parameter] might influence the ** choice of query plan if the parameter is the left-hand side of a [LIKE] ** or [GLOB] operator or if the parameter is compared to an indexed column ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. ** the **
    4. **
*/ SQLITE_API int sqlite3_prepare( sqlite3 *db, /* Database handle */ const char *zSql, /* SQL statement, UTF-8 encoded */ int nByte, /* Maximum length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const char **pzTail /* OUT: Pointer to unused portion of zSql */ ); SQLITE_API int sqlite3_prepare_v2( sqlite3 *db, /* Database handle */ const char *zSql, /* SQL statement, UTF-8 encoded */ int nByte, /* Maximum length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const char **pzTail /* OUT: Pointer to unused portion of zSql */ ); SQLITE_API int sqlite3_prepare16( sqlite3 *db, /* Database handle */ const void *zSql, /* SQL statement, UTF-16 encoded */ int nByte, /* Maximum length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const void **pzTail /* OUT: Pointer to unused portion of zSql */ ); SQLITE_API int sqlite3_prepare16_v2( sqlite3 *db, /* Database handle */ const void *zSql, /* SQL statement, UTF-16 encoded */ int nByte, /* Maximum length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const void **pzTail /* OUT: Pointer to unused portion of zSql */ ); /* ** CAPI3REF: Retrieving Statement SQL ** ** ^This interface can be used to retrieve a saved copy of the original ** SQL text used to create a [prepared statement] if that statement was ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. */ SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); /* ** CAPI3REF: Determine If An SQL Statement Writes The Database ** ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if ** and only if the [prepared statement] X makes no direct changes to ** the content of the database file. ** ** Note that [application-defined SQL functions] or ** [virtual tables] might change the database indirectly as a side effect. ** ^(For example, if an application defines a function "eval()" that ** calls [sqlite3_exec()], then the following SQL statement would ** change the database file through side-effects: ** ** 
**    SELECT eval('DELETE FROM t1') FROM t2;
**
** ** But because the [SELECT] statement does not change the database file ** directly, sqlite3_stmt_readonly() would still return true.)^ ** ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, ** since the statements themselves do not actually modify the database but ** rather they control the timing of when other statements modify the ** database. ^The [ATTACH] and [DETACH] statements also cause ** sqlite3_stmt_readonly() to return true since, while those statements ** change the configuration of a database connection, they do not make ** changes to the content of the database files on disk. */ SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); /* ** CAPI3REF: Determine If A Prepared Statement Has Been Reset ** ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the ** [prepared statement] S has been stepped at least once using ** [sqlite3_step(S)] but has not run to completion and/or has not ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) ** interface returns false if S is a NULL pointer. If S is not a ** NULL pointer and is not a pointer to a valid [prepared statement] ** object, then the behavior is undefined and probably undesirable. ** ** This interface can be used in combination [sqlite3_next_stmt()] ** to locate all prepared statements associated with a database ** connection that are in need of being reset. This can be used, ** for example, in diagnostic routines to search for prepared ** statements that are holding a transaction open. */ SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); /* ** CAPI3REF: Dynamically Typed Value Object ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} ** ** SQLite uses the sqlite3_value object to represent all values ** that can be stored in a database table. SQLite uses dynamic typing ** for the values it stores. ^Values stored in sqlite3_value objects ** can be integers, floating point values, strings, BLOBs, or NULL. ** ** An sqlite3_value object may be either "protected" or "unprotected". ** Some interfaces require a protected sqlite3_value. Other interfaces ** will accept either a protected or an unprotected sqlite3_value. ** Every interface that accepts sqlite3_value arguments specifies ** whether or not it requires a protected sqlite3_value. ** ** The terms "protected" and "unprotected" refer to whether or not ** a mutex is held. An internal mutex is held for a protected ** sqlite3_value object but no mutex is held for an unprotected ** sqlite3_value object. If SQLite is compiled to be single-threaded ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) ** or if SQLite is run in one of reduced mutex modes ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] ** then there is no distinction between protected and unprotected ** sqlite3_value objects and they can be used interchangeably. However, ** for maximum code portability it is recommended that applications ** still make the distinction between protected and unprotected ** sqlite3_value objects even when not strictly required. ** ** ^The sqlite3_value objects that are passed as parameters into the ** implementation of [application-defined SQL functions] are protected. ** ^The sqlite3_value object returned by ** [sqlite3_column_value()] is unprotected. ** Unprotected sqlite3_value objects may only be used with ** [sqlite3_result_value()] and [sqlite3_bind_value()]. ** The [sqlite3_value_blob | sqlite3_value_type()] family of ** interfaces require protected sqlite3_value objects. */ typedef struct Mem sqlite3_value; /* ** CAPI3REF: SQL Function Context Object ** ** The context in which an SQL function executes is stored in an ** sqlite3_context object. ^A pointer to an sqlite3_context object ** is always first parameter to [application-defined SQL functions]. ** The application-defined SQL function implementation will pass this ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], ** [sqlite3_aggregate_context()], [sqlite3_user_data()], ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], ** and/or [sqlite3_set_auxdata()]. */ typedef struct sqlite3_context sqlite3_context; /* ** CAPI3REF: Binding Values To Prepared Statements ** KEYWORDS: {host parameter} {host parameters} {host parameter name} ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} ** ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, ** literals may be replaced by a [parameter] that matches one of following ** templates: ** **
    **
  • ? **
  • ?NNN **
  • :VVV **
  • @VVV **
  • $VVV **
** ** In the templates above, NNN represents an integer literal, ** and VVV represents an alphanumeric identifier.)^ ^The values of these ** parameters (also called "host parameter names" or "SQL parameters") ** can be set using the sqlite3_bind_*() routines defined here. ** ** ^The first argument to the sqlite3_bind_*() routines is always ** a pointer to the [sqlite3_stmt] object returned from ** [sqlite3_prepare_v2()] or its variants. ** ** ^The second argument is the index of the SQL parameter to be set. ** ^The leftmost SQL parameter has an index of 1. ^When the same named ** SQL parameter is used more than once, second and subsequent ** occurrences have the same index as the first occurrence. ** ^The index for named parameters can be looked up using the ** [sqlite3_bind_parameter_index()] API if desired. ^The index ** for "?NNN" parameters is the value of NNN. ** ^The NNN value must be between 1 and the [sqlite3_limit()] ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). ** ** ^The third argument is the value to bind to the parameter. ** ** ^(In those routines that have a fourth argument, its value is the ** number of bytes in the parameter. To be clear: the value is the ** number of bytes in the value, not the number of characters.)^ ** ^If the fourth parameter is negative, the length of the string is ** the number of bytes up to the first zero terminator. ** If a non-negative fourth parameter is provided to sqlite3_bind_text() ** or sqlite3_bind_text16() then that parameter must be the byte offset ** where the NUL terminator would occur assuming the string were NUL ** terminated. If any NUL characters occur at byte offsets less than ** the value of the fourth parameter then the resulting string value will ** contain embedded NULs. The result of expressions involving strings ** with embedded NULs is undefined. ** ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or ** string after SQLite has finished with it. ^The destructor is called ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), ** sqlite3_bind_text(), or sqlite3_bind_text16() fails. ** ^If the fifth argument is ** the special value [SQLITE_STATIC], then SQLite assumes that the ** information is in static, unmanaged space and does not need to be freed. ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then ** SQLite makes its own private copy of the data immediately, before ** the sqlite3_bind_*() routine returns. ** ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory ** (just an integer to hold its size) while it is being processed. ** Zeroblobs are intended to serve as placeholders for BLOBs whose ** content is later written using ** [sqlite3_blob_open | incremental BLOB I/O] routines. ** ^A negative value for the zeroblob results in a zero-length BLOB. ** ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer ** for the [prepared statement] or with a prepared statement for which ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() ** routine is passed a [prepared statement] that has been finalized, the ** result is undefined and probably harmful. ** ** ^Bindings are not cleared by the [sqlite3_reset()] routine. ** ^Unbound parameters are interpreted as NULL. ** ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an ** [error code] if anything goes wrong. ** ^[SQLITE_RANGE] is returned if the parameter ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. ** ** See also: [sqlite3_bind_parameter_count()], ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. */ SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); /* ** CAPI3REF: Number Of SQL Parameters ** ** ^This routine can be used to find the number of [SQL parameters] ** in a [prepared statement]. SQL parameters are tokens of the ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as ** placeholders for values that are [sqlite3_bind_blob | bound] ** to the parameters at a later time. ** ** ^(This routine actually returns the index of the largest (rightmost) ** parameter. For all forms except ?NNN, this will correspond to the ** number of unique parameters. If parameters of the ?NNN form are used, ** there may be gaps in the list.)^ ** ** See also: [sqlite3_bind_blob|sqlite3_bind()], ** [sqlite3_bind_parameter_name()], and ** [sqlite3_bind_parameter_index()]. */ SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); /* ** CAPI3REF: Name Of A Host Parameter ** ** ^The sqlite3_bind_parameter_name(P,N) interface returns ** the name of the N-th [SQL parameter] in the [prepared statement] P. ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" ** respectively. ** In other words, the initial ":" or "$" or "@" or "?" ** is included as part of the name.)^ ** ^Parameters of the form "?" without a following integer have no name ** and are referred to as "nameless" or "anonymous parameters". ** ** ^The first host parameter has an index of 1, not 0. ** ** ^If the value N is out of range or if the N-th parameter is ** nameless, then NULL is returned. ^The returned string is ** always in UTF-8 encoding even if the named parameter was ** originally specified as UTF-16 in [sqlite3_prepare16()] or ** [sqlite3_prepare16_v2()]. ** ** See also: [sqlite3_bind_blob|sqlite3_bind()], ** [sqlite3_bind_parameter_count()], and ** [sqlite3_bind_parameter_index()]. */ SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); /* ** CAPI3REF: Index Of A Parameter With A Given Name ** ** ^Return the index of an SQL parameter given its name. ^The ** index value returned is suitable for use as the second ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero ** is returned if no matching parameter is found. ^The parameter ** name must be given in UTF-8 even if the original statement ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. ** ** See also: [sqlite3_bind_blob|sqlite3_bind()], ** [sqlite3_bind_parameter_count()], and ** [sqlite3_bind_parameter_index()]. */ SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); /* ** CAPI3REF: Reset All Bindings On A Prepared Statement ** ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. ** ^Use this routine to reset all host parameters to NULL. */ SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); /* ** CAPI3REF: Number Of Columns In A Result Set ** ** ^Return the number of columns in the result set returned by the ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL ** statement that does not return data (for example an [UPDATE]). ** ** See also: [sqlite3_data_count()] */ SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); /* ** CAPI3REF: Column Names In A Result Set ** ** ^These routines return the name assigned to a particular column ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() ** interface returns a pointer to a zero-terminated UTF-8 string ** and sqlite3_column_name16() returns a pointer to a zero-terminated ** UTF-16 string. ^The first parameter is the [prepared statement] ** that implements the [SELECT] statement. ^The second parameter is the ** column number. ^The leftmost column is number 0. ** ** ^The returned string pointer is valid until either the [prepared statement] ** is destroyed by [sqlite3_finalize()] or until the statement is automatically ** reprepared by the first call to [sqlite3_step()] for a particular run ** or until the next call to ** sqlite3_column_name() or sqlite3_column_name16() on the same column. ** ** ^If sqlite3_malloc() fails during the processing of either routine ** (for example during a conversion from UTF-8 to UTF-16) then a ** NULL pointer is returned. ** ** ^The name of a result column is the value of the "AS" clause for ** that column, if there is an AS clause. If there is no AS clause ** then the name of the column is unspecified and may change from ** one release of SQLite to the next. */ SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); /* ** CAPI3REF: Source Of Data In A Query Result ** ** ^These routines provide a means to determine the database, table, and ** table column that is the origin of a particular result column in ** [SELECT] statement. ** ^The name of the database or table or column can be returned as ** either a UTF-8 or UTF-16 string. ^The _database_ routines return ** the database name, the _table_ routines return the table name, and ** the origin_ routines return the column name. ** ^The returned string is valid until the [prepared statement] is destroyed ** using [sqlite3_finalize()] or until the statement is automatically ** reprepared by the first call to [sqlite3_step()] for a particular run ** or until the same information is requested ** again in a different encoding. ** ** ^The names returned are the original un-aliased names of the ** database, table, and column. ** ** ^The first argument to these interfaces is a [prepared statement]. ** ^These functions return information about the Nth result column returned by ** the statement, where N is the second function argument. ** ^The left-most column is column 0 for these routines. ** ** ^If the Nth column returned by the statement is an expression or ** subquery and is not a column value, then all of these functions return ** NULL. ^These routine might also return NULL if a memory allocation error ** occurs. ^Otherwise, they return the name of the attached database, table, ** or column that query result column was extracted from. ** ** ^As with all other SQLite APIs, those whose names end with "16" return ** UTF-16 encoded strings and the other functions return UTF-8. ** ** ^These APIs are only available if the library was compiled with the ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. ** ** If two or more threads call one or more of these routines against the same ** prepared statement and column at the same time then the results are ** undefined. ** ** If two or more threads call one or more ** [sqlite3_column_database_name | column metadata interfaces] ** for the same [prepared statement] and result column ** at the same time then the results are undefined. */ SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); /* ** CAPI3REF: Declared Datatype Of A Query Result ** ** ^(The first parameter is a [prepared statement]. ** If this statement is a [SELECT] statement and the Nth column of the ** returned result set of that [SELECT] is a table column (not an ** expression or subquery) then the declared type of the table ** column is returned.)^ ^If the Nth column of the result set is an ** expression or subquery, then a NULL pointer is returned. ** ^The returned string is always UTF-8 encoded. ** ** ^(For example, given the database schema: ** ** CREATE TABLE t1(c1 VARIANT); ** ** and the following statement to be compiled: ** ** SELECT c1 + 1, c1 FROM t1; ** ** this routine would return the string "VARIANT" for the second result ** column (i==1), and a NULL pointer for the first result column (i==0).)^ ** ** ^SQLite uses dynamic run-time typing. ^So just because a column ** is declared to contain a particular type does not mean that the ** data stored in that column is of the declared type. SQLite is ** strongly typed, but the typing is dynamic not static. ^Type ** is associated with individual values, not with the containers ** used to hold those values. */ SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); /* ** CAPI3REF: Evaluate An SQL Statement ** ** After a [prepared statement] has been prepared using either ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function ** must be called one or more times to evaluate the statement. ** ** The details of the behavior of the sqlite3_step() interface depend ** on whether the statement was prepared using the newer "v2" interface ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the ** new "v2" interface is recommended for new applications but the legacy ** interface will continue to be supported. ** ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. ** ^With the "v2" interface, any of the other [result codes] or ** [extended result codes] might be returned as well. ** ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the ** database locks it needs to do its job. ^If the statement is a [COMMIT] ** or occurs outside of an explicit transaction, then you can retry the ** statement. If the statement is not a [COMMIT] and occurs within an ** explicit transaction then you should rollback the transaction before ** continuing. ** ** ^[SQLITE_DONE] means that the statement has finished executing ** successfully. sqlite3_step() should not be called again on this virtual ** machine without first calling [sqlite3_reset()] to reset the virtual ** machine back to its initial state. ** ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] ** is returned each time a new row of data is ready for processing by the ** caller. The values may be accessed using the [column access functions]. ** sqlite3_step() is called again to retrieve the next row of data. ** ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint ** violation) has occurred. sqlite3_step() should not be called again on ** the VM. More information may be found by calling [sqlite3_errmsg()]. ** ^With the legacy interface, a more specific error code (for example, ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) ** can be obtained by calling [sqlite3_reset()] on the ** [prepared statement]. ^In the "v2" interface, ** the more specific error code is returned directly by sqlite3_step(). ** ** [SQLITE_MISUSE] means that the this routine was called inappropriately. ** Perhaps it was called on a [prepared statement] that has ** already been [sqlite3_finalize | finalized] or on one that had ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could ** be the case that the same database connection is being used by two or ** more threads at the same moment in time. ** ** For all versions of SQLite up to and including 3.6.23.1, a call to ** [sqlite3_reset()] was required after sqlite3_step() returned anything ** other than [SQLITE_ROW] before any subsequent invocation of ** sqlite3_step(). Failure to reset the prepared statement using ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began ** calling [sqlite3_reset()] automatically in this circumstance rather ** than returning [SQLITE_MISUSE]. This is not considered a compatibility ** break because any application that ever receives an SQLITE_MISUSE error ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option ** can be used to restore the legacy behavior. ** ** Goofy Interface Alert: In the legacy interface, the sqlite3_step() ** API always returns a generic error code, [SQLITE_ERROR], following any ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the ** specific [error codes] that better describes the error. ** We admit that this is a goofy design. The problem has been fixed ** with the "v2" interface. If you prepare all of your SQL statements ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, ** then the more specific [error codes] are returned directly ** by sqlite3_step(). The use of the "v2" interface is recommended. */ SQLITE_API int sqlite3_step(sqlite3_stmt*); /* ** CAPI3REF: Number of columns in a result set ** ** ^The sqlite3_data_count(P) interface returns the number of columns in the ** current row of the result set of [prepared statement] P. ** ^If prepared statement P does not have results ready to return ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of ** interfaces) then sqlite3_data_count(P) returns 0. ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) ** will return non-zero if previous call to [sqlite3_step](P) returned ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] ** where it always returns zero since each step of that multi-step ** pragma returns 0 columns of data. ** ** See also: [sqlite3_column_count()] */ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); /* ** CAPI3REF: Fundamental Datatypes ** KEYWORDS: SQLITE_TEXT ** ** ^(Every value in SQLite has one of five fundamental datatypes: ** **
    **
  • 64-bit signed integer **
  • 64-bit IEEE floating point number **
  • string **
  • BLOB **
  • NULL **
)^ ** ** These constants are codes for each of those types. ** ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 ** for a completely different meaning. Software that links against both ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not ** SQLITE_TEXT. */ #define SQLITE_INTEGER 1 #define SQLITE_FLOAT 2 #define SQLITE_BLOB 4 #define SQLITE_NULL 5 #ifdef SQLITE_TEXT # undef SQLITE_TEXT #else # define SQLITE_TEXT 3 #endif #define SQLITE3_TEXT 3 /* ** CAPI3REF: Result Values From A Query ** KEYWORDS: {column access functions} ** ** These routines form the "result set" interface. ** ** ^These routines return information about a single column of the current ** result row of a query. ^In every case the first argument is a pointer ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] ** that was returned from [sqlite3_prepare_v2()] or one of its variants) ** and the second argument is the index of the column for which information ** should be returned. ^The leftmost column of the result set has the index 0. ** ^The number of columns in the result can be determined using ** [sqlite3_column_count()]. ** ** If the SQL statement does not currently point to a valid row, or if the ** column index is out of range, the result is undefined. ** These routines may only be called when the most recent call to ** [sqlite3_step()] has returned [SQLITE_ROW] and neither ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. ** If any of these routines are called after [sqlite3_reset()] or ** [sqlite3_finalize()] or after [sqlite3_step()] has returned ** something other than [SQLITE_ROW], the results are undefined. ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] ** are called from a different thread while any of these routines ** are pending, then the results are undefined. ** ** ^The sqlite3_column_type() routine returns the ** [SQLITE_INTEGER | datatype code] for the initial data type ** of the result column. ^The returned value is one of [SQLITE_INTEGER], ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value ** returned by sqlite3_column_type() is only meaningful if no type ** conversions have occurred as described below. After a type conversion, ** the value returned by sqlite3_column_type() is undefined. Future ** versions of SQLite may change the behavior of sqlite3_column_type() ** following a type conversion. ** ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() ** routine returns the number of bytes in that BLOB or string. ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts ** the string to UTF-8 and then returns the number of bytes. ** ^If the result is a numeric value then sqlite3_column_bytes() uses ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns ** the number of bytes in that string. ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. ** ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() ** routine returns the number of bytes in that BLOB or string. ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts ** the string to UTF-16 and then returns the number of bytes. ** ^If the result is a numeric value then sqlite3_column_bytes16() uses ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns ** the number of bytes in that string. ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. ** ** ^The values returned by [sqlite3_column_bytes()] and ** [sqlite3_column_bytes16()] do not include the zero terminators at the end ** of the string. ^For clarity: the values returned by ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of ** bytes in the string, not the number of characters. ** ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), ** even empty strings, are always zero-terminated. ^The return ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. ** ** ^The object returned by [sqlite3_column_value()] is an ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. ** If the [unprotected sqlite3_value] object returned by ** [sqlite3_column_value()] is used in any other way, including calls ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], ** or [sqlite3_value_bytes()], then the behavior is undefined. ** ** These routines attempt to convert the value where appropriate. ^For ** example, if the internal representation is FLOAT and a text result ** is requested, [sqlite3_snprintf()] is used internally to perform the ** conversion automatically. ^(The following table details the conversions ** that are applied: ** **
** **
Internal
Type 		Requested
Type 		Conversion ** **
NULL INTEGER Result is 0 **
NULL FLOAT Result is 0.0 **
NULL TEXT Result is NULL pointer **
NULL BLOB Result is NULL pointer **
INTEGER FLOAT Convert from integer to float **
INTEGER TEXT ASCII rendering of the integer **
INTEGER BLOB Same as INTEGER->TEXT **
FLOAT INTEGER Convert from float to integer **
FLOAT TEXT ASCII rendering of the float **
FLOAT BLOB Same as FLOAT->TEXT **
TEXT INTEGER Use atoi() **
TEXT FLOAT Use atof() **
TEXT BLOB No change **
BLOB INTEGER Convert to TEXT then use atoi() **
BLOB FLOAT Convert to TEXT then use atof() **
BLOB TEXT Add a zero terminator if needed **
**
)^ ** ** The table above makes reference to standard C library functions atoi() ** and atof(). SQLite does not really use these functions. It has its ** own equivalent internal routines. The atoi() and atof() names are ** used in the table for brevity and because they are familiar to most ** C programmers. ** ** Note that when type conversions occur, pointers returned by prior ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or ** sqlite3_column_text16() may be invalidated. ** Type conversions and pointer invalidations might occur ** in the following cases: ** **
    **
  • The initial content is a BLOB and sqlite3_column_text() or ** sqlite3_column_text16() is called. A zero-terminator might ** need to be added to the string.
    • **
  • The initial content is UTF-8 text and sqlite3_column_bytes16() or ** sqlite3_column_text16() is called. The content must be converted ** to UTF-16.
    • **
  • The initial content is UTF-16 text and sqlite3_column_bytes() or ** sqlite3_column_text() is called. The content must be converted ** to UTF-8.
    • **
** ** ^Conversions between UTF-16be and UTF-16le are always done in place and do ** not invalidate a prior pointer, though of course the content of the buffer ** that the prior pointer references will have been modified. Other kinds ** of conversion are done in place when it is possible, but sometimes they ** are not possible and in those cases prior pointers are invalidated. ** ** The safest and easiest to remember policy is to invoke these routines ** in one of the following ways: ** **
    **
  • sqlite3_column_text() followed by sqlite3_column_bytes()
    • **
  • sqlite3_column_blob() followed by sqlite3_column_bytes()
    • **
  • sqlite3_column_text16() followed by sqlite3_column_bytes16()
    • **
** ** In other words, you should call sqlite3_column_text(), ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result ** into the desired format, then invoke sqlite3_column_bytes() or ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls ** to sqlite3_column_text() or sqlite3_column_blob() with calls to ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() ** with calls to sqlite3_column_bytes(). ** ** ^The pointers returned are valid until a type conversion occurs as ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or ** [sqlite3_finalize()] is called. ^The memory space used to hold strings ** and BLOBs is freed automatically. Do not pass the pointers returned ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into ** [sqlite3_free()]. ** ** ^(If a memory allocation error occurs during the evaluation of any ** of these routines, a default value is returned. The default value ** is either the integer 0, the floating point number 0.0, or a NULL ** pointer. Subsequent calls to [sqlite3_errcode()] will return ** [SQLITE_NOMEM].)^ */ SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); /* ** CAPI3REF: Destroy A Prepared Statement Object ** ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. ** ^If the most recent evaluation of the statement encountered no errors ** or if the statement is never been evaluated, then sqlite3_finalize() returns ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then ** sqlite3_finalize(S) returns the appropriate [error code] or ** [extended error code]. ** ** ^The sqlite3_finalize(S) routine can be called at any point during ** the life cycle of [prepared statement] S: ** before statement S is ever evaluated, after ** one or more calls to [sqlite3_reset()], or after any call ** to [sqlite3_step()] regardless of whether or not the statement has ** completed execution. ** ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. ** ** The application must finalize every [prepared statement] in order to avoid ** resource leaks. It is a grievous error for the application to try to use ** a prepared statement after it has been finalized. Any use of a prepared ** statement after it has been finalized can result in undefined and ** undesirable behavior such as segfaults and heap corruption. */ SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); /* ** CAPI3REF: Reset A Prepared Statement Object ** ** The sqlite3_reset() function is called to reset a [prepared statement] ** object back to its initial state, ready to be re-executed. ** ^Any SQL statement variables that had values bound to them using ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. ** Use [sqlite3_clear_bindings()] to reset the bindings. ** ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S ** back to the beginning of its program. ** ** ^If the most recent call to [sqlite3_step(S)] for the ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], ** or if [sqlite3_step(S)] has never before been called on S, ** then [sqlite3_reset(S)] returns [SQLITE_OK]. ** ** ^If the most recent call to [sqlite3_step(S)] for the ** [prepared statement] S indicated an error, then ** [sqlite3_reset(S)] returns an appropriate [error code]. ** ** ^The [sqlite3_reset(S)] interface does not change the values ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. */ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); /* ** CAPI3REF: Create Or Redefine SQL Functions ** KEYWORDS: {function creation routines} ** KEYWORDS: {application-defined SQL function} ** KEYWORDS: {application-defined SQL functions} ** ** ^These functions (collectively known as "function creation routines") ** are used to add SQL functions or aggregates or to redefine the behavior ** of existing SQL functions or aggregates. The only differences between ** these routines are the text encoding expected for ** the second parameter (the name of the function being created) ** and the presence or absence of a destructor callback for ** the application data pointer. ** ** ^The first parameter is the [database connection] to which the SQL ** function is to be added. ^If an application uses more than one database ** connection then application-defined SQL functions must be added ** to each database connection separately. ** ** ^The second parameter is the name of the SQL function to be created or ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 ** representation, exclusive of the zero-terminator. ^Note that the name ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. ** ^Any attempt to create a function with a longer name ** will result in [SQLITE_MISUSE] being returned. ** ** ^The third parameter (nArg) ** is the number of arguments that the SQL function or ** aggregate takes. ^If this parameter is -1, then the SQL function or ** aggregate may take any number of arguments between 0 and the limit ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third ** parameter is less than -1 or greater than 127 then the behavior is ** undefined. ** ** ^The fourth parameter, eTextRep, specifies what ** [SQLITE_UTF8 | text encoding] this SQL function prefers for ** its parameters. Every SQL function implementation must be able to work ** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be ** more efficient with one encoding than another. ^An application may ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple ** times with the same function but with different values of eTextRep. ** ^When multiple implementations of the same function are available, SQLite ** will pick the one that involves the least amount of data conversion. ** If there is only a single implementation which does not care what text ** encoding is used, then the fourth argument should be [SQLITE_ANY]. ** ** ^(The fifth parameter is an arbitrary pointer. The implementation of the ** function can gain access to this pointer using [sqlite3_user_data()].)^ ** ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are ** pointers to C-language functions that implement the SQL function or ** aggregate. ^A scalar SQL function requires an implementation of the xFunc ** callback only; NULL pointers must be passed as the xStep and xFinal ** parameters. ^An aggregate SQL function requires an implementation of xStep ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing ** SQL function or aggregate, pass NULL pointers for all three function ** callbacks. ** ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, ** then it is destructor for the application data pointer. ** The destructor is invoked when the function is deleted, either by being ** overloaded or when the database connection closes.)^ ** ^The destructor is also invoked if the call to ** sqlite3_create_function_v2() fails. ** ^When the destructor callback of the tenth parameter is invoked, it ** is passed a single argument which is a copy of the application data ** pointer which was the fifth parameter to sqlite3_create_function_v2(). ** ** ^It is permitted to register multiple implementations of the same ** functions with the same name but with either differing numbers of ** arguments or differing preferred text encodings. ^SQLite will use ** the implementation that most closely matches the way in which the ** SQL function is used. ^A function implementation with a non-negative ** nArg parameter is a better match than a function implementation with ** a negative nArg. ^A function where the preferred text encoding ** matches the database encoding is a better ** match than a function where the encoding is different. ** ^A function where the encoding difference is between UTF16le and UTF16be ** is a closer match than a function where the encoding difference is ** between UTF8 and UTF16. ** ** ^Built-in functions may be overloaded by new application-defined functions. ** ** ^An application-defined function is permitted to call other ** SQLite interfaces. However, such calls must not ** close the database connection nor finalize or reset the prepared ** statement in which the function is running. */ SQLITE_API int sqlite3_create_function( sqlite3 *db, const char *zFunctionName, int nArg, int eTextRep, void *pApp, void (*xFunc)(sqlite3_context*,int,sqlite3_value**), void (*xStep)(sqlite3_context*,int,sqlite3_value**), void (*xFinal)(sqlite3_context*) ); SQLITE_API int sqlite3_create_function16( sqlite3 *db, const void *zFunctionName, int nArg, int eTextRep, void *pApp, void (*xFunc)(sqlite3_context*,int,sqlite3_value**), void (*xStep)(sqlite3_context*,int,sqlite3_value**), void (*xFinal)(sqlite3_context*) ); SQLITE_API int sqlite3_create_function_v2( sqlite3 *db, const char *zFunctionName, int nArg, int eTextRep, void *pApp, void (*xFunc)(sqlite3_context*,int,sqlite3_value**), void (*xStep)(sqlite3_context*,int,sqlite3_value**), void (*xFinal)(sqlite3_context*), void(*xDestroy)(void*) ); /* ** CAPI3REF: Text Encodings ** ** These constant define integer codes that represent the various ** text encodings supported by SQLite. */ #define SQLITE_UTF8 1 #define SQLITE_UTF16LE 2 #define SQLITE_UTF16BE 3 #define SQLITE_UTF16 4 /* Use native byte order */ #define SQLITE_ANY 5 /* sqlite3_create_function only */ #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ /* ** CAPI3REF: Deprecated Functions ** DEPRECATED ** ** These functions are [deprecated]. In order to maintain ** backwards compatibility with older code, these functions continue ** to be supported. However, new applications should avoid ** the use of these functions. To help encourage people to avoid ** using these functions, we are not going to tell you what they do. */ #ifndef SQLITE_OMIT_DEPRECATED SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); #endif /* ** CAPI3REF: Obtaining SQL Function Parameter Values ** ** The C-language implementation of SQL functions and aggregates uses ** this set of interface routines to access the parameter values on ** the function or aggregate. ** ** The xFunc (for scalar functions) or xStep (for aggregates) parameters ** to [sqlite3_create_function()] and [sqlite3_create_function16()] ** define callbacks that implement the SQL functions and aggregates. ** The 3rd parameter to these callbacks is an array of pointers to ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for ** each parameter to the SQL function. These routines are used to ** extract values from the [sqlite3_value] objects. ** ** These routines work only with [protected sqlite3_value] objects. ** Any attempt to use these routines on an [unprotected sqlite3_value] ** object results in undefined behavior. ** ** ^These routines work just like the corresponding [column access functions] ** except that these routines take a single [protected sqlite3_value] object ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. ** ** ^The sqlite3_value_text16() interface extracts a UTF-16 string ** in the native byte-order of the host machine. ^The ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces ** extract UTF-16 strings as big-endian and little-endian respectively. ** ** ^(The sqlite3_value_numeric_type() interface attempts to apply ** numeric affinity to the value. This means that an attempt is ** made to convert the value to an integer or floating point. If ** such a conversion is possible without loss of information (in other ** words, if the value is a string that looks like a number) ** then the conversion is performed. Otherwise no conversion occurs. ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ ** ** Please pay particular attention to the fact that the pointer returned ** from [sqlite3_value_blob()], [sqlite3_value_text()], or ** [sqlite3_value_text16()] can be invalidated by a subsequent call to ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], ** or [sqlite3_value_text16()]. ** ** These routines must be called from the same thread as ** the SQL function that supplied the [sqlite3_value*] parameters. */ SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); SQLITE_API int sqlite3_value_bytes(sqlite3_value*); SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); SQLITE_API double sqlite3_value_double(sqlite3_value*); SQLITE_API int sqlite3_value_int(sqlite3_value*); SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); SQLITE_API int sqlite3_value_type(sqlite3_value*); SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); /* ** CAPI3REF: Obtain Aggregate Function Context ** ** Implementations of aggregate SQL functions use this ** routine to allocate memory for storing their state. ** ** ^The first time the sqlite3_aggregate_context(C,N) routine is called ** for a particular aggregate function, SQLite ** allocates N of memory, zeroes out that memory, and returns a pointer ** to the new memory. ^On second and subsequent calls to ** sqlite3_aggregate_context() for the same aggregate function instance, ** the same buffer is returned. Sqlite3_aggregate_context() is normally ** called once for each invocation of the xStep callback and then one ** last time when the xFinal callback is invoked. ^(When no rows match ** an aggregate query, the xStep() callback of the aggregate function ** implementation is never called and xFinal() is called exactly once. ** In those cases, sqlite3_aggregate_context() might be called for the ** first time from within xFinal().)^ ** ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is ** less than or equal to zero or if a memory allocate error occurs. ** ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is ** determined by the N parameter on first successful call. Changing the ** value of N in subsequent call to sqlite3_aggregate_context() within ** the same aggregate function instance will not resize the memory ** allocation.)^ ** ** ^SQLite automatically frees the memory allocated by ** sqlite3_aggregate_context() when the aggregate query concludes. ** ** The first parameter must be a copy of the ** [sqlite3_context | SQL function context] that is the first parameter ** to the xStep or xFinal callback routine that implements the aggregate ** function. ** ** This routine must be called from the same thread in which ** the aggregate SQL function is running. */ SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); /* ** CAPI3REF: User Data For Functions ** ** ^The sqlite3_user_data() interface returns a copy of ** the pointer that was the pUserData parameter (the 5th parameter) ** of the [sqlite3_create_function()] ** and [sqlite3_create_function16()] routines that originally ** registered the application defined function. ** ** This routine must be called from the same thread in which ** the application-defined function is running. */ SQLITE_API void *sqlite3_user_data(sqlite3_context*); /* ** CAPI3REF: Database Connection For Functions ** ** ^The sqlite3_context_db_handle() interface returns a copy of ** the pointer to the [database connection] (the 1st parameter) ** of the [sqlite3_create_function()] ** and [sqlite3_create_function16()] routines that originally ** registered the application defined function. */ SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); /* ** CAPI3REF: Function Auxiliary Data ** ** The following two functions may be used by scalar SQL functions to ** associate metadata with argument values. If the same value is passed to ** multiple invocations of the same SQL function during query execution, under ** some circumstances the associated metadata may be preserved. This may ** be used, for example, to add a regular-expression matching scalar ** function. The compiled version of the regular expression is stored as ** metadata associated with the SQL value passed as the regular expression ** pattern. The compiled regular expression can be reused on multiple ** invocations of the same function so that the original pattern string ** does not need to be recompiled on each invocation. ** ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata ** associated by the sqlite3_set_auxdata() function with the Nth argument ** value to the application-defined function. ^If no metadata has been ever ** been set for the Nth argument of the function, or if the corresponding ** function parameter has changed since the meta-data was set, ** then sqlite3_get_auxdata() returns a NULL pointer. ** ** ^The sqlite3_set_auxdata() interface saves the metadata ** pointed to by its 3rd parameter as the metadata for the N-th ** argument of the application-defined function. Subsequent ** calls to sqlite3_get_auxdata() might return this data, if it has ** not been destroyed. ** ^If it is not NULL, SQLite will invoke the destructor ** function given by the 4th parameter to sqlite3_set_auxdata() on ** the metadata when the corresponding function parameter changes ** or when the SQL statement completes, whichever comes first. ** ** SQLite is free to call the destructor and drop metadata on any ** parameter of any function at any time. ^The only guarantee is that ** the destructor will be called before the metadata is dropped. ** ** ^(In practice, metadata is preserved between function calls for ** expressions that are constant at compile time. This includes literal ** values and [parameters].)^ ** ** These routines must be called from the same thread in which ** the SQL function is running. */ SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); /* ** CAPI3REF: Constants Defining Special Destructor Behavior ** ** These are special values for the destructor that is passed in as the ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor ** argument is SQLITE_STATIC, it means that the content pointer is constant ** and will never change. It does not need to be destroyed. ^The ** SQLITE_TRANSIENT value means that the content will likely change in ** the near future and that SQLite should make its own private copy of ** the content before returning. ** ** The typedef is necessary to work around problems in certain ** C++ compilers. See ticket #2191. */ typedef void (*sqlite3_destructor_type)(void*); #define SQLITE_STATIC ((sqlite3_destructor_type)0) #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) /* ** CAPI3REF: Setting The Result Of An SQL Function ** ** These routines are used by the xFunc or xFinal callbacks that ** implement SQL functions and aggregates. See ** [sqlite3_create_function()] and [sqlite3_create_function16()] ** for additional information. ** ** These functions work very much like the [parameter binding] family of ** functions used to bind values to host parameters in prepared statements. ** Refer to the [SQL parameter] documentation for additional information. ** ** ^The sqlite3_result_blob() interface sets the result from ** an application-defined function to be the BLOB whose content is pointed ** to by the second parameter and which is N bytes long where N is the ** third parameter. ** ** ^The sqlite3_result_zeroblob() interfaces set the result of ** the application-defined function to be a BLOB containing all zero ** bytes and N bytes in size, where N is the value of the 2nd parameter. ** ** ^The sqlite3_result_double() interface sets the result from ** an application-defined function to be a floating point value specified ** by its 2nd argument. ** ** ^The sqlite3_result_error() and sqlite3_result_error16() functions ** cause the implemented SQL function to throw an exception. ** ^SQLite uses the string pointed to by the ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() ** as the text of an error message. ^SQLite interprets the error ** message string from sqlite3_result_error() as UTF-8. ^SQLite ** interprets the string from sqlite3_result_error16() as UTF-16 in native ** byte order. ^If the third parameter to sqlite3_result_error() ** or sqlite3_result_error16() is negative then SQLite takes as the error ** message all text up through the first zero character. ** ^If the third parameter to sqlite3_result_error() or ** sqlite3_result_error16() is non-negative then SQLite takes that many ** bytes (not characters) from the 2nd parameter as the error message. ** ^The sqlite3_result_error() and sqlite3_result_error16() ** routines make a private copy of the error message text before ** they return. Hence, the calling function can deallocate or ** modify the text after they return without harm. ** ^The sqlite3_result_error_code() function changes the error code ** returned by SQLite as a result of an error in a function. ^By default, ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. ** ** ^The sqlite3_result_toobig() interface causes SQLite to throw an error ** indicating that a string or BLOB is too long to represent. ** ** ^The sqlite3_result_nomem() interface causes SQLite to throw an error ** indicating that a memory allocation failed. ** ** ^The sqlite3_result_int() interface sets the return value ** of the application-defined function to be the 32-bit signed integer ** value given in the 2nd argument. ** ^The sqlite3_result_int64() interface sets the return value ** of the application-defined function to be the 64-bit signed integer ** value given in the 2nd argument. ** ** ^The sqlite3_result_null() interface sets the return value ** of the application-defined function to be NULL. ** ** ^The sqlite3_result_text(), sqlite3_result_text16(), ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces ** set the return value of the application-defined function to be ** a text string which is represented as UTF-8, UTF-16 native byte order, ** UTF-16 little endian, or UTF-16 big endian, respectively. ** ^SQLite takes the text result from the application from ** the 2nd parameter of the sqlite3_result_text* interfaces. ** ^If the 3rd parameter to the sqlite3_result_text* interfaces ** is negative, then SQLite takes result text from the 2nd parameter ** through the first zero character. ** ^If the 3rd parameter to the sqlite3_result_text* interfaces ** is non-negative, then as many bytes (not characters) of the text ** pointed to by the 2nd parameter are taken as the application-defined ** function result. If the 3rd parameter is non-negative, then it ** must be the byte offset into the string where the NUL terminator would ** appear if the string where NUL terminated. If any NUL characters occur ** in the string at a byte offset that is less than the value of the 3rd ** parameter, then the resulting string will contain embedded NULs and the ** result of expressions operating on strings with embedded NULs is undefined. ** ^If the 4th parameter to the sqlite3_result_text* interfaces ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that ** function as the destructor on the text or BLOB result when it has ** finished using that result. ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite ** assumes that the text or BLOB result is in constant space and does not ** copy the content of the parameter nor call a destructor on the content ** when it has finished using that result. ** ^If the 4th parameter to the sqlite3_result_text* interfaces ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT ** then SQLite makes a copy of the result into space obtained from ** from [sqlite3_malloc()] before it returns. ** ** ^The sqlite3_result_value() interface sets the result of ** the application-defined function to be a copy the ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] ** so that the [sqlite3_value] specified in the parameter may change or ** be deallocated after sqlite3_result_value() returns without harm. ** ^A [protected sqlite3_value] object may always be used where an ** [unprotected sqlite3_value] object is required, so either ** kind of [sqlite3_value] object can be used with this interface. ** ** If these routines are called from within the different thread ** than the one containing the application-defined function that received ** the [sqlite3_context] pointer, the results are undefined. */ SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); SQLITE_API void sqlite3_result_double(sqlite3_context*, double); SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); SQLITE_API void sqlite3_result_int(sqlite3_context*, int); SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); SQLITE_API void sqlite3_result_null(sqlite3_context*); SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); /* ** CAPI3REF: Define New Collating Sequences ** ** ^These functions add, remove, or modify a [collation] associated ** with the [database connection] specified as the first argument. ** ** ^The name of the collation is a UTF-8 string ** for sqlite3_create_collation() and sqlite3_create_collation_v2() ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are ** considered to be the same name. ** ** ^(The third argument (eTextRep) must be one of the constants: **
    **
  • [SQLITE_UTF8], **
  • [SQLITE_UTF16LE], **
  • [SQLITE_UTF16BE], **
  • [SQLITE_UTF16], or **
  • [SQLITE_UTF16_ALIGNED]. **
)^ ** ^The eTextRep argument determines the encoding of strings passed ** to the collating function callback, xCallback. ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep ** force strings to be UTF16 with native byte order. ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin ** on an even byte address. ** ** ^The fourth argument, pArg, is an application data pointer that is passed ** through as the first argument to the collating function callback. ** ** ^The fifth argument, xCallback, is a pointer to the collating function. ** ^Multiple collating functions can be registered using the same name but ** with different eTextRep parameters and SQLite will use whichever ** function requires the least amount of data transformation. ** ^If the xCallback argument is NULL then the collating function is ** deleted. ^When all collating functions having the same name are deleted, ** that collation is no longer usable. ** ** ^The collating function callback is invoked with a copy of the pArg ** application data pointer and with two strings in the encoding specified ** by the eTextRep argument. The collating function must return an ** integer that is negative, zero, or positive ** if the first string is less than, equal to, or greater than the second, ** respectively. A collating function must always return the same answer ** given the same inputs. If two or more collating functions are registered ** to the same collation name (using different eTextRep values) then all ** must give an equivalent answer when invoked with equivalent strings. ** The collating function must obey the following properties for all ** strings A, B, and C: ** **
    **
  1. If A==B then B==A. **
  2. If A==B and B==C then A==C. **
  3. If A<B THEN B>A. **
  4. If A<B and B<C then A<C. **
** ** If a collating function fails any of the above constraints and that ** collating function is registered and used, then the behavior of SQLite ** is undefined. ** ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() ** with the addition that the xDestroy callback is invoked on pArg when ** the collating function is deleted. ** ^Collating functions are deleted when they are overridden by later ** calls to the collation creation functions or when the ** [database connection] is closed using [sqlite3_close()]. ** ** ^The xDestroy callback is not called if the ** sqlite3_create_collation_v2() function fails. Applications that invoke ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should ** check the return code and dispose of the application data pointer ** themselves rather than expecting SQLite to deal with it for them. ** This is different from every other SQLite interface. The inconsistency ** is unfortunate but cannot be changed without breaking backwards ** compatibility. ** ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. */ SQLITE_API int sqlite3_create_collation( sqlite3*, const char *zName, int eTextRep, void *pArg, int(*xCompare)(void*,int,const void*,int,const void*) ); SQLITE_API int sqlite3_create_collation_v2( sqlite3*, const char *zName, int eTextRep, void *pArg, int(*xCompare)(void*,int,const void*,int,const void*), void(*xDestroy)(void*) ); SQLITE_API int sqlite3_create_collation16( sqlite3*, const void *zName, int eTextRep, void *pArg, int(*xCompare)(void*,int,const void*,int,const void*) ); /* ** CAPI3REF: Collation Needed Callbacks ** ** ^To avoid having to register all collation sequences before a database ** can be used, a single callback function may be registered with the ** [database connection] to be invoked whenever an undefined collation ** sequence is required. ** ** ^If the function is registered using the sqlite3_collation_needed() API, ** then it is passed the names of undefined collation sequences as strings ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, ** the names are passed as UTF-16 in machine native byte order. ** ^A call to either function replaces the existing collation-needed callback. ** ** ^(When the callback is invoked, the first argument passed is a copy ** of the second argument to sqlite3_collation_needed() or ** sqlite3_collation_needed16(). The second argument is the database ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation ** sequence function required. The fourth parameter is the name of the ** required collation sequence.)^ ** ** The callback function should register the desired collation using ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or ** [sqlite3_create_collation_v2()]. */ SQLITE_API int sqlite3_collation_needed( sqlite3*, void*, void(*)(void*,sqlite3*,int eTextRep,const char*) ); SQLITE_API int sqlite3_collation_needed16( sqlite3*, void*, void(*)(void*,sqlite3*,int eTextRep,const void*) ); #ifdef SQLITE_HAS_CODEC /* ** Specify the key for an encrypted database. This routine should be ** called right after sqlite3_open(). ** ** The code to implement this API is not available in the public release ** of SQLite. */ SQLITE_API int sqlite3_key( sqlite3 *db, /* Database to be rekeyed */ const void *pKey, int nKey /* The key */ ); /* ** Change the key on an open database. If the current database is not ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the ** database is decrypted. ** ** The code to implement this API is not available in the public release ** of SQLite. */ SQLITE_API int sqlite3_rekey( sqlite3 *db, /* Database to be rekeyed */ const void *pKey, int nKey /* The new key */ ); /* ** Specify the activation key for a SEE database. Unless ** activated, none of the SEE routines will work. */ SQLITE_API void sqlite3_activate_see( const char *zPassPhrase /* Activation phrase */ ); #endif #ifdef SQLITE_ENABLE_CEROD /* ** Specify the activation key for a CEROD database. Unless ** activated, none of the CEROD routines will work. */ SQLITE_API void sqlite3_activate_cerod( const char *zPassPhrase /* Activation phrase */ ); #endif /* ** CAPI3REF: Suspend Execution For A Short Time ** ** The sqlite3_sleep() function causes the current thread to suspend execution ** for at least a number of milliseconds specified in its parameter. ** ** If the operating system does not support sleep requests with ** millisecond time resolution, then the time will be rounded up to ** the nearest second. The number of milliseconds of sleep actually ** requested from the operating system is returned. ** ** ^SQLite implements this interface by calling the xSleep() ** method of the default [sqlite3_vfs] object. If the xSleep() method ** of the default VFS is not implemented correctly, or not implemented at ** all, then the behavior of sqlite3_sleep() may deviate from the description ** in the previous paragraphs. */ SQLITE_API int sqlite3_sleep(int); /* ** CAPI3REF: Name Of The Folder Holding Temporary Files ** ** ^(If this global variable is made to point to a string which is ** the name of a folder (a.k.a. directory), then all temporary files ** created by SQLite when using a built-in [sqlite3_vfs | VFS] ** will be placed in that directory.)^ ^If this variable ** is a NULL pointer, then SQLite performs a search for an appropriate ** temporary file directory. ** ** It is not safe to read or modify this variable in more than one ** thread at a time. It is not safe to read or modify this variable ** if a [database connection] is being used at the same time in a separate ** thread. ** It is intended that this variable be set once ** as part of process initialization and before any SQLite interface ** routines have been called and that this variable remain unchanged ** thereafter. ** ** ^The [temp_store_directory pragma] may modify this variable and cause ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, ** the [temp_store_directory pragma] always assumes that any string ** that this variable points to is held in memory obtained from ** [sqlite3_malloc] and the pragma may attempt to free that memory ** using [sqlite3_free]. ** Hence, if this variable is modified directly, either it should be ** made NULL or made to point to memory obtained from [sqlite3_malloc] ** or else the use of the [temp_store_directory pragma] should be avoided. */ SQLITE_API char *sqlite3_temp_directory; /* ** CAPI3REF: Test For Auto-Commit Mode ** KEYWORDS: {autocommit mode} ** ** ^The sqlite3_get_autocommit() interface returns non-zero or ** zero if the given database connection is or is not in autocommit mode, ** respectively. ^Autocommit mode is on by default. ** ^Autocommit mode is disabled by a [BEGIN] statement. ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. ** ** If certain kinds of errors occur on a statement within a multi-statement ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the ** transaction might be rolled back automatically. The only way to ** find out whether SQLite automatically rolled back the transaction after ** an error is to use this function. ** ** If another thread changes the autocommit status of the database ** connection while this routine is running, then the return value ** is undefined. */ SQLITE_API int sqlite3_get_autocommit(sqlite3*); /* ** CAPI3REF: Find The Database Handle Of A Prepared Statement ** ** ^The sqlite3_db_handle interface returns the [database connection] handle ** to which a [prepared statement] belongs. ^The [database connection] ** returned by sqlite3_db_handle is the same [database connection] ** that was the first argument ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to ** create the statement in the first place. */ SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); /* ** CAPI3REF: Return The Filename For A Database Connection ** ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename ** associated with database N of connection D. ^The main database file ** has the name "main". If there is no attached database N on the database ** connection D, or if database N is a temporary or in-memory database, then ** a NULL pointer is returned. ** ** ^The filename returned by this function is the output of the ** xFullPathname method of the [VFS]. ^In other words, the filename ** will be an absolute pathname, even if the filename used ** to open the database originally was a URI or relative pathname. */ SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); /* ** CAPI3REF: Determine if a database is read-only ** ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N ** of connection D is read-only, 0 if it is read/write, or -1 if N is not ** the name of a database on connection D. */ SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); /* ** CAPI3REF: Find the next prepared statement ** ** ^This interface returns a pointer to the next [prepared statement] after ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL ** then this interface returns a pointer to the first prepared statement ** associated with the database connection pDb. ^If no prepared statement ** satisfies the conditions of this routine, it returns NULL. ** ** The [database connection] pointer D in a call to ** [sqlite3_next_stmt(D,S)] must refer to an open database ** connection and in particular must not be a NULL pointer. */ SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); /* ** CAPI3REF: Commit And Rollback Notification Callbacks ** ** ^The sqlite3_commit_hook() interface registers a callback ** function to be invoked whenever a transaction is [COMMIT | committed]. ** ^Any callback set by a previous call to sqlite3_commit_hook() ** for the same database connection is overridden. ** ^The sqlite3_rollback_hook() interface registers a callback ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. ** ^Any callback set by a previous call to sqlite3_rollback_hook() ** for the same database connection is overridden. ** ^The pArg argument is passed through to the callback. ** ^If the callback on a commit hook function returns non-zero, ** then the commit is converted into a rollback. ** ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions ** return the P argument from the previous call of the same function ** on the same [database connection] D, or NULL for ** the first call for each function on D. ** ** The commit and rollback hook callbacks are not reentrant. ** The callback implementation must not do anything that will modify ** the database connection that invoked the callback. Any actions ** to modify the database connection must be deferred until after the ** completion of the [sqlite3_step()] call that triggered the commit ** or rollback hook in the first place. ** Note that running any other SQL statements, including SELECT statements, ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify ** the database connections for the meaning of "modify" in this paragraph. ** ** ^Registering a NULL function disables the callback. ** ** ^When the commit hook callback routine returns zero, the [COMMIT] ** operation is allowed to continue normally. ^If the commit hook ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. ** ^The rollback hook is invoked on a rollback that results from a commit ** hook returning non-zero, just as it would be with any other rollback. ** ** ^For the purposes of this API, a transaction is said to have been ** rolled back if an explicit "ROLLBACK" statement is executed, or ** an error or constraint causes an implicit rollback to occur. ** ^The rollback callback is not invoked if a transaction is ** automatically rolled back because the database connection is closed. ** ** See also the [sqlite3_update_hook()] interface. */ SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); /* ** CAPI3REF: Data Change Notification Callbacks ** ** ^The sqlite3_update_hook() interface registers a callback function ** with the [database connection] identified by the first argument ** to be invoked whenever a row is updated, inserted or deleted. ** ^Any callback set by a previous call to this function ** for the same database connection is overridden. ** ** ^The second argument is a pointer to the function to invoke when a ** row is updated, inserted or deleted. ** ^The first argument to the callback is a copy of the third argument ** to sqlite3_update_hook(). ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], ** or [SQLITE_UPDATE], depending on the operation that caused the callback ** to be invoked. ** ^The third and fourth arguments to the callback contain pointers to the ** database and table name containing the affected row. ** ^The final callback parameter is the [rowid] of the row. ** ^In the case of an update, this is the [rowid] after the update takes place. ** ** ^(The update hook is not invoked when internal system tables are ** modified (i.e. sqlite_master and sqlite_sequence).)^ ** ** ^In the current implementation, the update hook ** is not invoked when duplication rows are deleted because of an ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook ** invoked when rows are deleted using the [truncate optimization]. ** The exceptions defined in this paragraph might change in a future ** release of SQLite. ** ** The update hook implementation must not do anything that will modify ** the database connection that invoked the update hook. Any actions ** to modify the database connection must be deferred until after the ** completion of the [sqlite3_step()] call that triggered the update hook. ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their ** database connections for the meaning of "modify" in this paragraph. ** ** ^The sqlite3_update_hook(D,C,P) function ** returns the P argument from the previous call ** on the same [database connection] D, or NULL for ** the first call on D. ** ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] ** interfaces. */ SQLITE_API void *sqlite3_update_hook( sqlite3*, void(*)(void *,int ,char const *,char const *,sqlite3_int64), void* ); /* ** CAPI3REF: Enable Or Disable Shared Pager Cache ** KEYWORDS: {shared cache} ** ** ^(This routine enables or disables the sharing of the database cache ** and schema data structures between [database connection | connections] ** to the same database. Sharing is enabled if the argument is true ** and disabled if the argument is false.)^ ** ** ^Cache sharing is enabled and disabled for an entire process. ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, ** sharing was enabled or disabled for each thread separately. ** ** ^(The cache sharing mode set by this interface effects all subsequent ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. ** Existing database connections continue use the sharing mode ** that was in effect at the time they were opened.)^ ** ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled ** successfully. An [error code] is returned otherwise.)^ ** ** ^Shared cache is disabled by default. But this might change in ** future releases of SQLite. Applications that care about shared ** cache setting should set it explicitly. ** ** See Also: [SQLite Shared-Cache Mode] */ SQLITE_API int sqlite3_enable_shared_cache(int); /* ** CAPI3REF: Attempt To Free Heap Memory ** ** ^The sqlite3_release_memory() interface attempts to free N bytes ** of heap memory by deallocating non-essential memory allocations ** held by the database library. Memory used to cache database ** pages to improve performance is an example of non-essential memory. ** ^sqlite3_release_memory() returns the number of bytes actually freed, ** which might be more or less than the amount requested. ** ^The sqlite3_release_memory() routine is a no-op returning zero ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. ** ** See also: [sqlite3_db_release_memory()] */ SQLITE_API int sqlite3_release_memory(int); /* ** CAPI3REF: Free Memory Used By A Database Connection ** ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap ** memory as possible from database connection D. Unlike the ** [sqlite3_release_memory()] interface, this interface is effect even ** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is ** omitted. ** ** See also: [sqlite3_release_memory()] */ SQLITE_API int sqlite3_db_release_memory(sqlite3*); /* ** CAPI3REF: Impose A Limit On Heap Size ** ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the ** soft limit on the amount of heap memory that may be allocated by SQLite. ** ^SQLite strives to keep heap memory utilization below the soft heap ** limit by reducing the number of pages held in the page cache ** as heap memory usages approaches the limit. ** ^The soft heap limit is "soft" because even though SQLite strives to stay ** below the limit, it will exceed the limit rather than generate ** an [SQLITE_NOMEM] error. In other words, the soft heap limit ** is advisory only. ** ** ^The return value from sqlite3_soft_heap_limit64() is the size of ** the soft heap limit prior to the call, or negative in the case of an ** error. ^If the argument N is negative ** then no change is made to the soft heap limit. Hence, the current ** size of the soft heap limit can be determined by invoking ** sqlite3_soft_heap_limit64() with a negative argument. ** ** ^If the argument N is zero then the soft heap limit is disabled. ** ** ^(The soft heap limit is not enforced in the current implementation ** if one or more of following conditions are true: ** **
    **
  • The soft heap limit is set to zero. **
  • Memory accounting is disabled using a combination of the ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. **
  • An alternative page cache implementation is specified using ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). **
  • The page cache allocates from its own memory pool supplied ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than ** from the heap. **
)^ ** ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], ** the soft heap limit is enforced on every memory allocation. Without ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced ** when memory is allocated by the page cache. Testing suggests that because ** the page cache is the predominate memory user in SQLite, most ** applications will achieve adequate soft heap limit enforcement without ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. ** ** The circumstances under which SQLite will enforce the soft heap limit may ** changes in future releases of SQLite. */ SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); /* ** CAPI3REF: Deprecated Soft Heap Limit Interface ** DEPRECATED ** ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] ** interface. This routine is provided for historical compatibility ** only. All new applications should use the ** [sqlite3_soft_heap_limit64()] interface rather than this one. */ SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); /* ** CAPI3REF: Extract Metadata About A Column Of A Table ** ** ^This routine returns metadata about a specific column of a specific ** database table accessible using the [database connection] handle ** passed as the first function argument. ** ** ^The column is identified by the second, third and fourth parameters to ** this function. ^The second parameter is either the name of the database ** (i.e. "main", "temp", or an attached database) containing the specified ** table or NULL. ^If it is NULL, then all attached databases are searched ** for the table using the same algorithm used by the database engine to ** resolve unqualified table references. ** ** ^The third and fourth parameters to this function are the table and column ** name of the desired column, respectively. Neither of these parameters ** may be NULL. ** ** ^Metadata is returned by writing to the memory locations passed as the 5th ** and subsequent parameters to this function. ^Any of these arguments may be ** NULL, in which case the corresponding element of metadata is omitted. ** ** ^(
** **
Parameter Output
Type 		Description ** **
5th const char* Data type **
6th const char* Name of default collation sequence **
7th int True if column has a NOT NULL constraint **
8th int True if column is part of the PRIMARY KEY **
9th int True if column is [AUTOINCREMENT] **
**
)^ ** ** ^The memory pointed to by the character pointers returned for the ** declaration type and collation sequence is valid only until the next ** call to any SQLite API function. ** ** ^If the specified table is actually a view, an [error code] is returned. ** ** ^If the specified column is "rowid", "oid" or "_rowid_" and an ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output ** parameters are set for the explicitly declared column. ^(If there is no ** explicitly declared [INTEGER PRIMARY KEY] column, then the output ** parameters are set as follows: ** ** 
**     data type: "INTEGER"
**     collation sequence: "BINARY"
**     not null: 0
**     primary key: 1
**     auto increment: 0
**
)^ ** ** ^(This function may load one or more schemas from database files. If an ** error occurs during this process, or if the requested table or column ** cannot be found, an [error code] is returned and an error message left ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ ** ** ^This API is only available if the library was compiled with the ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. */ SQLITE_API int sqlite3_table_column_metadata( sqlite3 *db, /* Connection handle */ const char *zDbName, /* Database name or NULL */ const char *zTableName, /* Table name */ const char *zColumnName, /* Column name */ char const **pzDataType, /* OUTPUT: Declared data type */ char const **pzCollSeq, /* OUTPUT: Collation sequence name */ int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ int *pPrimaryKey, /* OUTPUT: True if column part of PK */ int *pAutoinc /* OUTPUT: True if column is auto-increment */ ); /* ** CAPI3REF: Load An Extension ** ** ^This interface loads an SQLite extension library from the named file. ** ** ^The sqlite3_load_extension() interface attempts to load an ** SQLite extension library contained in the file zFile. ** ** ^The entry point is zProc. ** ^zProc may be 0, in which case the name of the entry point ** defaults to "sqlite3_extension_init". ** ^The sqlite3_load_extension() interface returns ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. ** ^If an error occurs and pzErrMsg is not 0, then the ** [sqlite3_load_extension()] interface shall attempt to ** fill *pzErrMsg with error message text stored in memory ** obtained from [sqlite3_malloc()]. The calling function ** should free this memory by calling [sqlite3_free()]. ** ** ^Extension loading must be enabled using ** [sqlite3_enable_load_extension()] prior to calling this API, ** otherwise an error will be returned. ** ** See also the [load_extension() SQL function]. */ SQLITE_API int sqlite3_load_extension( sqlite3 *db, /* Load the extension into this database connection */ const char *zFile, /* Name of the shared library containing extension */ const char *zProc, /* Entry point. Derived from zFile if 0 */ char **pzErrMsg /* Put error message here if not 0 */ ); /* ** CAPI3REF: Enable Or Disable Extension Loading ** ** ^So as not to open security holes in older applications that are ** unprepared to deal with extension loading, and as a means of disabling ** extension loading while evaluating user-entered SQL, the following API ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. ** ** ^Extension loading is off by default. See ticket #1863. ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 ** to turn extension loading on and call it with onoff==0 to turn ** it back off again. */ SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); /* ** CAPI3REF: Automatically Load Statically Linked Extensions ** ** ^This interface causes the xEntryPoint() function to be invoked for ** each new [database connection] that is created. The idea here is that ** xEntryPoint() is the entry point for a statically linked SQLite extension ** that is to be automatically loaded into all new database connections. ** ** ^(Even though the function prototype shows that xEntryPoint() takes ** no arguments and returns void, SQLite invokes xEntryPoint() with three ** arguments and expects and integer result as if the signature of the ** entry point where as follows: ** ** 
**    int xEntryPoint(
**      sqlite3 *db,
**      const char **pzErrMsg,
**      const struct sqlite3_api_routines *pThunk
**    );
**
)^ ** ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg ** is NULL before calling the xEntryPoint(). ^SQLite will invoke ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. ** ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already ** on the list of automatic extensions is a harmless no-op. ^No entry point ** will be called more than once for each database connection that is opened. ** ** See also: [sqlite3_reset_auto_extension()]. */ SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); /* ** CAPI3REF: Reset Automatic Extension Loading ** ** ^This interface disables all automatic extensions previously ** registered using [sqlite3_auto_extension()]. */ SQLITE_API void sqlite3_reset_auto_extension(void); /* ** The interface to the virtual-table mechanism is currently considered ** to be experimental. The interface might change in incompatible ways. ** If this is a problem for you, do not use the interface at this time. ** ** When the virtual-table mechanism stabilizes, we will declare the ** interface fixed, support it indefinitely, and remove this comment. */ /* ** Structures used by the virtual table interface */ typedef struct sqlite3_vtab sqlite3_vtab; typedef struct sqlite3_index_info sqlite3_index_info; typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; typedef struct sqlite3_module sqlite3_module; /* ** CAPI3REF: Virtual Table Object ** KEYWORDS: sqlite3_module {virtual table module} ** ** This structure, sometimes called a "virtual table module", ** defines the implementation of a [virtual tables]. ** This structure consists mostly of methods for the module. ** ** ^A virtual table module is created by filling in a persistent ** instance of this structure and passing a pointer to that instance ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. ** ^The registration remains valid until it is replaced by a different ** module or until the [database connection] closes. The content ** of this structure must not change while it is registered with ** any database connection. */ struct sqlite3_module { int iVersion; int (*xCreate)(sqlite3*, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVTab, char**); int (*xConnect)(sqlite3*, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVTab, char**); int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); int (*xDisconnect)(sqlite3_vtab *pVTab); int (*xDestroy)(sqlite3_vtab *pVTab); int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); int (*xClose)(sqlite3_vtab_cursor*); int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, int argc, sqlite3_value **argv); int (*xNext)(sqlite3_vtab_cursor*); int (*xEof)(sqlite3_vtab_cursor*); int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); int (*xBegin)(sqlite3_vtab *pVTab); int (*xSync)(sqlite3_vtab *pVTab); int (*xCommit)(sqlite3_vtab *pVTab); int (*xRollback)(sqlite3_vtab *pVTab); int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), void **ppArg); int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); /* The methods above are in version 1 of the sqlite_module object. Those ** below are for version 2 and greater. */ int (*xSavepoint)(sqlite3_vtab *pVTab, int); int (*xRelease)(sqlite3_vtab *pVTab, int); int (*xRollbackTo)(sqlite3_vtab *pVTab, int); }; /* ** CAPI3REF: Virtual Table Indexing Information ** KEYWORDS: sqlite3_index_info ** ** The sqlite3_index_info structure and its substructures is used as part ** of the [virtual table] interface to ** pass information into and receive the reply from the [xBestIndex] ** method of a [virtual table module]. The fields under **Inputs** are the ** inputs to xBestIndex and are read-only. xBestIndex inserts its ** results into the **Outputs** fields. ** ** ^(The aConstraint[] array records WHERE clause constraints of the form: ** **
column OP expr
** ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is ** stored in aConstraint[].op using one of the ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ ** ^(The index of the column is stored in ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the ** expr on the right-hand side can be evaluated (and thus the constraint ** is usable) and false if it cannot.)^ ** ** ^The optimizer automatically inverts terms of the form "expr OP column" ** and makes other simplifications to the WHERE clause in an attempt to ** get as many WHERE clause terms into the form shown above as possible. ** ^The aConstraint[] array only reports WHERE clause terms that are ** relevant to the particular virtual table being queried. ** ** ^Information about the ORDER BY clause is stored in aOrderBy[]. ** ^Each term of aOrderBy records a column of the ORDER BY clause. ** ** The [xBestIndex] method must fill aConstraintUsage[] with information ** about what parameters to pass to xFilter. ^If argvIndex>0 then ** the right-hand side of the corresponding aConstraint[] is evaluated ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit ** is true, then the constraint is assumed to be fully handled by the ** virtual table and is not checked again by SQLite.)^ ** ** ^The idxNum and idxPtr values are recorded and passed into the ** [xFilter] method. ** ^[sqlite3_free()] is used to free idxPtr if and only if ** needToFreeIdxPtr is true. ** ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in ** the correct order to satisfy the ORDER BY clause so that no separate ** sorting step is required. ** ** ^The estimatedCost value is an estimate of the cost of doing the ** particular lookup. A full scan of a table with N entries should have ** a cost of N. A binary search of a table of N entries should have a ** cost of approximately log(N). */ 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 */ unsigned char desc; /* True for DESC. False for ASC. */ } *aOrderBy; /* The ORDER BY clause */ /* Outputs */ struct sqlite3_index_constraint_usage { int argvIndex; /* if >0, constraint is part of argv to xFilter */ unsigned char omit; /* Do not code a test for this constraint */ } *aConstraintUsage; int idxNum; /* Number used to identify the index */ char *idxStr; /* String, possibly obtained from sqlite3_malloc */ int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ int orderByConsumed; /* True if output is already ordered */ double estimatedCost; /* Estimated cost of using this index */ }; /* ** CAPI3REF: Virtual Table Constraint Operator Codes ** ** These macros defined the allowed values for the ** [sqlite3_index_info].aConstraint[].op field. Each value represents ** an operator that is part of a constraint term in the wHERE clause of ** a query that uses a [virtual table]. */ #define SQLITE_INDEX_CONSTRAINT_EQ 2 #define SQLITE_INDEX_CONSTRAINT_GT 4 #define SQLITE_INDEX_CONSTRAINT_LE 8 #define SQLITE_INDEX_CONSTRAINT_LT 16 #define SQLITE_INDEX_CONSTRAINT_GE 32 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 /* ** CAPI3REF: Register A Virtual Table Implementation ** ** ^These routines are used to register a new [virtual table module] name. ** ^Module names must be registered before ** creating a new [virtual table] using the module and before using a ** preexisting [virtual table] for the module. ** ** ^The module name is registered on the [database connection] specified ** by the first parameter. ^The name of the module is given by the ** second parameter. ^The third parameter is a pointer to ** the implementation of the [virtual table module]. ^The fourth ** parameter is an arbitrary client data pointer that is passed through ** into the [xCreate] and [xConnect] methods of the virtual table module ** when a new virtual table is be being created or reinitialized. ** ** ^The sqlite3_create_module_v2() interface has a fifth parameter which ** is a pointer to a destructor for the pClientData. ^SQLite will ** invoke the destructor function (if it is not NULL) when SQLite ** no longer needs the pClientData pointer. ^The destructor will also ** be invoked if the call to sqlite3_create_module_v2() fails. ** ^The sqlite3_create_module() ** interface is equivalent to sqlite3_create_module_v2() with a NULL ** destructor. */ SQLITE_API int sqlite3_create_module( sqlite3 *db, /* SQLite connection to register module with */ const char *zName, /* Name of the module */ const sqlite3_module *p, /* Methods for the module */ void *pClientData /* Client data for xCreate/xConnect */ ); SQLITE_API int sqlite3_create_module_v2( sqlite3 *db, /* SQLite connection to register module with */ const char *zName, /* Name of the module */ const sqlite3_module *p, /* Methods for the module */ void *pClientData, /* Client data for xCreate/xConnect */ void(*xDestroy)(void*) /* Module destructor function */ ); /* ** CAPI3REF: Virtual Table Instance Object ** KEYWORDS: sqlite3_vtab ** ** Every [virtual table module] implementation uses a subclass ** of this object to describe a particular instance ** of the [virtual table]. Each subclass will ** be tailored to the specific needs of the module implementation. ** The purpose of this superclass is to define certain fields that are ** common to all module implementations. ** ** ^Virtual tables methods can set an error message by assigning a ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should ** take care that any prior string is freed by a call to [sqlite3_free()] ** prior to assigning a new string to zErrMsg. ^After the error message ** is delivered up to the client application, the string will be automatically ** freed by sqlite3_free() and the zErrMsg field will be zeroed. */ struct sqlite3_vtab { const sqlite3_module *pModule; /* The module for this virtual table */ int nRef; /* NO LONGER USED */ char *zErrMsg; /* Error message from sqlite3_mprintf() */ /* Virtual table implementations will typically add additional fields */ }; /* ** CAPI3REF: Virtual Table Cursor Object ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} ** ** Every [virtual table module] implementation uses a subclass of the ** following structure to describe cursors that point into the ** [virtual table] and are used ** to loop through the virtual table. Cursors are created using the ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed ** by the [sqlite3_module.xClose | xClose] method. Cursors are used ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods ** of the module. Each module implementation will define ** the content of a cursor structure to suit its own needs. ** ** This superclass exists in order to define fields of the cursor that ** are common to all implementations. */ struct sqlite3_vtab_cursor { sqlite3_vtab *pVtab; /* Virtual table of this cursor */ /* Virtual table implementations will typically add additional fields */ }; /* ** CAPI3REF: Declare The Schema Of A Virtual Table ** ** ^The [xCreate] and [xConnect] methods of a ** [virtual table module] call this interface ** to declare the format (the names and datatypes of the columns) of ** the virtual tables they implement. */ SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); /* ** CAPI3REF: Overload A Function For A Virtual Table ** ** ^(Virtual tables can provide alternative implementations of functions ** using the [xFindFunction] method of the [virtual table module]. ** But global versions of those functions ** must exist in order to be overloaded.)^ ** ** ^(This API makes sure a global version of a function with a particular ** name and number of parameters exists. If no such function exists ** before this API is called, a new function is created.)^ ^The implementation ** of the new function always causes an exception to be thrown. So ** the new function is not good for anything by itself. Its only ** purpose is to be a placeholder function that can be overloaded ** by a [virtual table]. */ SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); /* ** The interface to the virtual-table mechanism defined above (back up ** to a comment remarkably similar to this one) is currently considered ** to be experimental. The interface might change in incompatible ways. ** If this is a problem for you, do not use the interface at this time. ** ** When the virtual-table mechanism stabilizes, we will declare the ** interface fixed, support it indefinitely, and remove this comment. */ /* ** CAPI3REF: A Handle To An Open BLOB ** KEYWORDS: {BLOB handle} {BLOB handles} ** ** An instance of this object represents an open BLOB on which ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. ** ^Objects of this type are created by [sqlite3_blob_open()] ** and destroyed by [sqlite3_blob_close()]. ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces ** can be used to read or write small subsections of the BLOB. ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. */ typedef struct sqlite3_blob sqlite3_blob; /* ** CAPI3REF: Open A BLOB For Incremental I/O ** ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located ** in row iRow, column zColumn, table zTable in database zDb; ** in other words, the same BLOB that would be selected by: ** ** 
**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
**
)^ ** ** ^If the flags parameter is non-zero, then the BLOB is opened for read ** and write access. ^If it is zero, the BLOB is opened for read access. ** ^It is not possible to open a column that is part of an index or primary ** key for writing. ^If [foreign key constraints] are enabled, it is ** not possible to open a column that is part of a [child key] for writing. ** ** ^Note that the database name is not the filename that contains ** the database but rather the symbolic name of the database that ** appears after the AS keyword when the database is connected using [ATTACH]. ** ^For the main database file, the database name is "main". ** ^For TEMP tables, the database name is "temp". ** ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set ** to be a null pointer.)^ ** ^This function sets the [database connection] error code and message ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related ** functions. ^Note that the *ppBlob variable is always initialized in a ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob ** regardless of the success or failure of this routine. ** ** ^(If the row that a BLOB handle points to is modified by an ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects ** then the BLOB handle is marked as "expired". ** This is true if any column of the row is changed, even a column ** other than the one the BLOB handle is open on.)^ ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. ** ^(Changes written into a BLOB prior to the BLOB expiring are not ** rolled back by the expiration of the BLOB. Such changes will eventually ** commit if the transaction continues to completion.)^ ** ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of ** the opened blob. ^The size of a blob may not be changed by this ** interface. Use the [UPDATE] SQL command to change the size of a ** blob. ** ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces ** and the built-in [zeroblob] SQL function can be used, if desired, ** to create an empty, zero-filled blob in which to read or write using ** this interface. ** ** To avoid a resource leak, every open [BLOB handle] should eventually ** be released by a call to [sqlite3_blob_close()]. */ SQLITE_API int sqlite3_blob_open( sqlite3*, const char *zDb, const char *zTable, const char *zColumn, sqlite3_int64 iRow, int flags, sqlite3_blob **ppBlob ); /* ** CAPI3REF: Move a BLOB Handle to a New Row ** ** ^This function is used to move an existing blob handle so that it points ** to a different row of the same database table. ^The new row is identified ** by the rowid value passed as the second argument. Only the row can be ** changed. ^The database, table and column on which the blob handle is open ** remain the same. Moving an existing blob handle to a new row can be ** faster than closing the existing handle and opening a new one. ** ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - ** it must exist and there must be either a blob or text value stored in ** the nominated column.)^ ^If the new row is not present in the table, or if ** it does not contain a blob or text value, or if another error occurs, an ** SQLite error code is returned and the blob handle is considered aborted. ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle ** always returns zero. ** ** ^This function sets the database handle error code and message. */ SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); /* ** CAPI3REF: Close A BLOB Handle ** ** ^Closes an open [BLOB handle]. ** ** ^Closing a BLOB shall cause the current transaction to commit ** if there are no other BLOBs, no pending prepared statements, and the ** database connection is in [autocommit mode]. ** ^If any writes were made to the BLOB, they might be held in cache ** until the close operation if they will fit. ** ** ^(Closing the BLOB often forces the changes ** out to disk and so if any I/O errors occur, they will likely occur ** at the time when the BLOB is closed. Any errors that occur during ** closing are reported as a non-zero return value.)^ ** ** ^(The BLOB is closed unconditionally. Even if this routine returns ** an error code, the BLOB is still closed.)^ ** ** ^Calling this routine with a null pointer (such as would be returned ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. */ SQLITE_API int sqlite3_blob_close(sqlite3_blob *); /* ** CAPI3REF: Return The Size Of An Open BLOB ** ** ^Returns the size in bytes of the BLOB accessible via the ** successfully opened [BLOB handle] in its only argument. ^The ** incremental blob I/O routines can only read or overwriting existing ** blob content; they cannot change the size of a blob. ** ** This routine only works on a [BLOB handle] which has been created ** by a prior successful call to [sqlite3_blob_open()] and which has not ** been closed by [sqlite3_blob_close()]. Passing any other pointer in ** to this routine results in undefined and probably undesirable behavior. */ SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); /* ** CAPI3REF: Read Data From A BLOB Incrementally ** ** ^(This function is used to read data from an open [BLOB handle] into a ** caller-supplied buffer. N bytes of data are copied into buffer Z ** from the open BLOB, starting at offset iOffset.)^ ** ** ^If offset iOffset is less than N bytes from the end of the BLOB, ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is ** less than zero, [SQLITE_ERROR] is returned and no data is read. ** ^The size of the blob (and hence the maximum value of N+iOffset) ** can be determined using the [sqlite3_blob_bytes()] interface. ** ** ^An attempt to read from an expired [BLOB handle] fails with an ** error code of [SQLITE_ABORT]. ** ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. ** Otherwise, an [error code] or an [extended error code] is returned.)^ ** ** This routine only works on a [BLOB handle] which has been created ** by a prior successful call to [sqlite3_blob_open()] and which has not ** been closed by [sqlite3_blob_close()]. Passing any other pointer in ** to this routine results in undefined and probably undesirable behavior. ** ** See also: [sqlite3_blob_write()]. */ SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); /* ** CAPI3REF: Write Data Into A BLOB Incrementally ** ** ^This function is used to write data into an open [BLOB handle] from a ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z ** into the open BLOB, starting at offset iOffset. ** ** ^If the [BLOB handle] passed as the first argument was not opened for ** writing (the flags parameter to [sqlite3_blob_open()] was zero), ** this function returns [SQLITE_READONLY]. ** ** ^This function may only modify the contents of the BLOB; it is ** not possible to increase the size of a BLOB using this API. ** ^If offset iOffset is less than N bytes from the end of the BLOB, ** [SQLITE_ERROR] is returned and no data is written. ^If N is ** less than zero [SQLITE_ERROR] is returned and no data is written. ** The size of the BLOB (and hence the maximum value of N+iOffset) ** can be determined using the [sqlite3_blob_bytes()] interface. ** ** ^An attempt to write to an expired [BLOB handle] fails with an ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred ** before the [BLOB handle] expired are not rolled back by the ** expiration of the handle, though of course those changes might ** have been overwritten by the statement that expired the BLOB handle ** or by other independent statements. ** ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. ** Otherwise, an [error code] or an [extended error code] is returned.)^ ** ** This routine only works on a [BLOB handle] which has been created ** by a prior successful call to [sqlite3_blob_open()] and which has not ** been closed by [sqlite3_blob_close()]. Passing any other pointer in ** to this routine results in undefined and probably undesirable behavior. ** ** See also: [sqlite3_blob_read()]. */ SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); /* ** CAPI3REF: Virtual File System Objects ** ** A virtual filesystem (VFS) is an [sqlite3_vfs] object ** that SQLite uses to interact ** with the underlying operating system. Most SQLite builds come with a ** single default VFS that is appropriate for the host computer. ** New VFSes can be registered and existing VFSes can be unregistered. ** The following interfaces are provided. ** ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. ** ^Names are case sensitive. ** ^Names are zero-terminated UTF-8 strings. ** ^If there is no match, a NULL pointer is returned. ** ^If zVfsName is NULL then the default VFS is returned. ** ** ^New VFSes are registered with sqlite3_vfs_register(). ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. ** ^The same VFS can be registered multiple times without injury. ** ^To make an existing VFS into the default VFS, register it again ** with the makeDflt flag set. If two different VFSes with the ** same name are registered, the behavior is undefined. If a ** VFS is registered with a name that is NULL or an empty string, ** then the behavior is undefined. ** ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. ** ^(If the default VFS is unregistered, another VFS is chosen as ** the default. The choice for the new VFS is arbitrary.)^ */ SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); /* ** CAPI3REF: Mutexes ** ** The SQLite core uses these routines for thread ** synchronization. Though they are intended for internal ** use by SQLite, code that links against SQLite is ** permitted to use any of these routines. ** ** The SQLite source code contains multiple implementations ** of these mutex routines. An appropriate implementation ** is selected automatically at compile-time. ^(The following ** implementations are available in the SQLite core: ** **
    **
  • SQLITE_MUTEX_OS2 **
  • SQLITE_MUTEX_PTHREADS **
  • SQLITE_MUTEX_W32 **
  • SQLITE_MUTEX_NOOP **
)^ ** ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines ** that does no real locking and is appropriate for use in ** a single-threaded application. ^The SQLITE_MUTEX_OS2, ** SQLITE_MUTEX_PTHREADS, and SQLITE_MUTEX_W32 implementations ** are appropriate for use on OS/2, Unix, and Windows. ** ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex ** implementation is included with the library. In this case the ** application must supply a custom mutex implementation using the ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function ** before calling sqlite3_initialize() or any other public sqlite3_ ** function that calls sqlite3_initialize().)^ ** ** ^The sqlite3_mutex_alloc() routine allocates a new ** mutex and returns a pointer to it. ^If it returns NULL ** that means that a mutex could not be allocated. ^SQLite ** will unwind its stack and return an error. ^(The argument ** to sqlite3_mutex_alloc() is one of these integer constants: ** **
    **
  • SQLITE_MUTEX_FAST **
  • SQLITE_MUTEX_RECURSIVE **
  • SQLITE_MUTEX_STATIC_MASTER **
  • SQLITE_MUTEX_STATIC_MEM **
  • SQLITE_MUTEX_STATIC_MEM2 **
  • SQLITE_MUTEX_STATIC_PRNG **
  • SQLITE_MUTEX_STATIC_LRU **
  • SQLITE_MUTEX_STATIC_LRU2 **
)^ ** ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) ** cause sqlite3_mutex_alloc() to create ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. ** The mutex implementation does not need to make a distinction ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does ** not want to. ^SQLite will only request a recursive mutex in ** cases where it really needs one. ^If a faster non-recursive mutex ** implementation is available on the host platform, the mutex subsystem ** might return such a mutex in response to SQLITE_MUTEX_FAST. ** ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return ** a pointer to a static preexisting mutex. ^Six static mutexes are ** used by the current version of SQLite. Future versions of SQLite ** may add additional static mutexes. Static mutexes are for internal ** use by SQLite only. Applications that use SQLite mutexes should ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or ** SQLITE_MUTEX_RECURSIVE. ** ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() ** returns a different mutex on every call. ^But for the static ** mutex types, the same mutex is returned on every call that has ** the same type number. ** ** ^The sqlite3_mutex_free() routine deallocates a previously ** allocated dynamic mutex. ^SQLite is careful to deallocate every ** dynamic mutex that it allocates. The dynamic mutexes must not be in ** use when they are deallocated. Attempting to deallocate a static ** mutex results in undefined behavior. ^SQLite never deallocates ** a static mutex. ** ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt ** to enter a mutex. ^If another thread is already within the mutex, ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] ** upon successful entry. ^(Mutexes created using ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. ** In such cases the, ** mutex must be exited an equal number of times before another thread ** can enter.)^ ^(If the same thread tries to enter any other ** kind of mutex more than once, the behavior is undefined. ** SQLite will never exhibit ** such behavior in its own use of mutexes.)^ ** ** ^(Some systems (for example, Windows 95) do not support the operation ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() ** will always return SQLITE_BUSY. The SQLite core only ever uses ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ ** ** ^The sqlite3_mutex_leave() routine exits a mutex that was ** previously entered by the same thread. ^(The behavior ** is undefined if the mutex is not currently entered by the ** calling thread or is not currently allocated. SQLite will ** never do either.)^ ** ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or ** sqlite3_mutex_leave() is a NULL pointer, then all three routines ** behave as no-ops. ** ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. */ SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); /* ** CAPI3REF: Mutex Methods Object ** ** An instance of this structure defines the low-level routines ** used to allocate and use mutexes. ** ** Usually, the default mutex implementations provided by SQLite are ** sufficient, however the user has the option of substituting a custom ** implementation for specialized deployments or systems for which SQLite ** does not provide a suitable implementation. In this case, the user ** creates and populates an instance of this structure to pass ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. ** Additionally, an instance of this structure can be used as an ** output variable when querying the system for the current mutex ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. ** ** ^The xMutexInit method defined by this structure is invoked as ** part of system initialization by the sqlite3_initialize() function. ** ^The xMutexInit routine is called by SQLite exactly once for each ** effective call to [sqlite3_initialize()]. ** ** ^The xMutexEnd method defined by this structure is invoked as ** part of system shutdown by the sqlite3_shutdown() function. The ** implementation of this method is expected to release all outstanding ** resources obtained by the mutex methods implementation, especially ** those obtained by the xMutexInit method. ^The xMutexEnd() ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. ** ** ^(The remaining seven methods defined by this structure (xMutexAlloc, ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and ** xMutexNotheld) implement the following interfaces (respectively): ** **
    **
  • [sqlite3_mutex_alloc()]
    • **
  • [sqlite3_mutex_free()]
    • **
  • [sqlite3_mutex_enter()]
    • **
  • [sqlite3_mutex_try()]
    • **
  • [sqlite3_mutex_leave()]
    • **
  • [sqlite3_mutex_held()]
    • **
  • [sqlite3_mutex_notheld()]
    • **
)^ ** ** The only difference is that the public sqlite3_XXX functions enumerated ** above silently ignore any invocations that pass a NULL pointer instead ** of a valid mutex handle. The implementations of the methods defined ** by this structure are not required to handle this case, the results ** of passing a NULL pointer instead of a valid mutex handle are undefined ** (i.e. it is acceptable to provide an implementation that segfaults if ** it is passed a NULL pointer). ** ** The xMutexInit() method must be threadsafe. ^It must be harmless to ** invoke xMutexInit() multiple times within the same process and without ** intervening calls to xMutexEnd(). Second and subsequent calls to ** xMutexInit() must be no-ops. ** ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite ** memory allocation for a fast or recursive mutex. ** ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is ** called, but only if the prior call to xMutexInit returned SQLITE_OK. ** If xMutexInit fails in any way, it is expected to clean up after itself ** prior to returning. */ typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; struct sqlite3_mutex_methods { int (*xMutexInit)(void); int (*xMutexEnd)(void); sqlite3_mutex *(*xMutexAlloc)(int); void (*xMutexFree)(sqlite3_mutex *); void (*xMutexEnter)(sqlite3_mutex *); int (*xMutexTry)(sqlite3_mutex *); void (*xMutexLeave)(sqlite3_mutex *); int (*xMutexHeld)(sqlite3_mutex *); int (*xMutexNotheld)(sqlite3_mutex *); }; /* ** CAPI3REF: Mutex Verification Routines ** ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines ** are intended for use inside assert() statements. ^The SQLite core ** never uses these routines except inside an assert() and applications ** are advised to follow the lead of the core. ^The SQLite core only ** provides implementations for these routines when it is compiled ** with the SQLITE_DEBUG flag. ^External mutex implementations ** are only required to provide these routines if SQLITE_DEBUG is ** defined and if NDEBUG is not defined. ** ** ^These routines should return true if the mutex in their argument ** is held or not held, respectively, by the calling thread. ** ** ^The implementation is not required to provide versions of these ** routines that actually work. If the implementation does not provide working ** versions of these routines, it should at least provide stubs that always ** return true so that one does not get spurious assertion failures. ** ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then ** the routine should return 1. This seems counter-intuitive since ** clearly the mutex cannot be held if it does not exist. But ** the reason the mutex does not exist is because the build is not ** using mutexes. And we do not want the assert() containing the ** call to sqlite3_mutex_held() to fail, so a non-zero return is ** the appropriate thing to do. ^The sqlite3_mutex_notheld() ** interface should also return 1 when given a NULL pointer. */ #ifndef NDEBUG SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); #endif /* ** CAPI3REF: Mutex Types ** ** The [sqlite3_mutex_alloc()] interface takes a single argument ** which is one of these integer constants. ** ** The set of static mutexes may change from one SQLite release to the ** next. Applications that override the built-in mutex logic must be ** prepared to accommodate additional static mutexes. */ #define SQLITE_MUTEX_FAST 0 #define SQLITE_MUTEX_RECURSIVE 1 #define SQLITE_MUTEX_STATIC_MASTER 2 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ /* ** CAPI3REF: Retrieve the mutex for a database connection ** ** ^This interface returns a pointer the [sqlite3_mutex] object that ** serializes access to the [database connection] given in the argument ** when the [threading mode] is Serialized. ** ^If the [threading mode] is Single-thread or Multi-thread then this ** routine returns a NULL pointer. */ SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); /* ** CAPI3REF: Low-Level Control Of Database Files ** ** ^The [sqlite3_file_control()] interface makes a direct call to the ** xFileControl method for the [sqlite3_io_methods] object associated ** with a particular database identified by the second argument. ^The ** name of the database is "main" for the main database or "temp" for the ** TEMP database, or the name that appears after the AS keyword for ** databases that are added using the [ATTACH] SQL command. ** ^A NULL pointer can be used in place of "main" to refer to the ** main database file. ** ^The third and fourth parameters to this routine ** are passed directly through to the second and third parameters of ** the xFileControl method. ^The return value of the xFileControl ** method becomes the return value of this routine. ** ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes ** a pointer to the underlying [sqlite3_file] object to be written into ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER ** case is a short-circuit path which does not actually invoke the ** underlying sqlite3_io_methods.xFileControl method. ** ** ^If the second parameter (zDbName) does not match the name of any ** open database file, then SQLITE_ERROR is returned. ^This error ** code is not remembered and will not be recalled by [sqlite3_errcode()] ** or [sqlite3_errmsg()]. The underlying xFileControl method might ** also return SQLITE_ERROR. There is no way to distinguish between ** an incorrect zDbName and an SQLITE_ERROR return from the underlying ** xFileControl method. ** ** See also: [SQLITE_FCNTL_LOCKSTATE] */ SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); /* ** CAPI3REF: Testing Interface ** ** ^The sqlite3_test_control() interface is used to read out internal ** state of SQLite and to inject faults into SQLite for testing ** purposes. ^The first parameter is an operation code that determines ** the number, meaning, and operation of all subsequent parameters. ** ** This interface is not for use by applications. It exists solely ** for verifying the correct operation of the SQLite library. Depending ** on how the SQLite library is compiled, this interface might not exist. ** ** The details of the operation codes, their meanings, the parameters ** they take, and what they do are all subject to change without notice. ** Unlike most of the SQLite API, this function is not guaranteed to ** operate consistently from one release to the next. */ SQLITE_API int sqlite3_test_control(int op, ...); /* ** CAPI3REF: Testing Interface Operation Codes ** ** These constants are the valid operation code parameters used ** as the first argument to [sqlite3_test_control()]. ** ** These parameters and their meanings are subject to change ** without notice. These values are for testing purposes only. ** Applications should not use any of these parameters or the ** [sqlite3_test_control()] interface. */ #define SQLITE_TESTCTRL_FIRST 5 #define SQLITE_TESTCTRL_PRNG_SAVE 5 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 #define SQLITE_TESTCTRL_PRNG_RESET 7 #define SQLITE_TESTCTRL_BITVEC_TEST 8 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 #define SQLITE_TESTCTRL_PENDING_BYTE 11 #define SQLITE_TESTCTRL_ASSERT 12 #define SQLITE_TESTCTRL_ALWAYS 13 #define SQLITE_TESTCTRL_RESERVE 14 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 #define SQLITE_TESTCTRL_ISKEYWORD 16 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 #define SQLITE_TESTCTRL_LAST 19 /* ** CAPI3REF: SQLite Runtime Status ** ** ^This interface is used to retrieve runtime status information ** about the performance of SQLite, and optionally to reset various ** highwater marks. ^The first argument is an integer code for ** the specific parameter to measure. ^(Recognized integer codes ** are of the form [status parameters | SQLITE_STATUS_...].)^ ** ^The current value of the parameter is returned into *pCurrent. ** ^The highest recorded value is returned in *pHighwater. ^If the ** resetFlag is true, then the highest record value is reset after ** *pHighwater is written. ^(Some parameters do not record the highest ** value. For those parameters ** nothing is written into *pHighwater and the resetFlag is ignored.)^ ** ^(Other parameters record only the highwater mark and not the current ** value. For these latter parameters nothing is written into *pCurrent.)^ ** ** ^The sqlite3_status() routine returns SQLITE_OK on success and a ** non-zero [error code] on failure. ** ** This routine is threadsafe but is not atomic. This routine can be ** called while other threads are running the same or different SQLite ** interfaces. However the values returned in *pCurrent and ** *pHighwater reflect the status of SQLite at different points in time ** and it is possible that another thread might change the parameter ** in between the times when *pCurrent and *pHighwater are written. ** ** See also: [sqlite3_db_status()] */ SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); /* ** CAPI3REF: Status Parameters ** KEYWORDS: {status parameters} ** ** These integer constants designate various run-time status parameters ** that can be returned by [sqlite3_status()]. ** **
** [[SQLITE_STATUS_MEMORY_USED]] ^(
SQLITE_STATUS_MEMORY_USED
**
This parameter is the current amount of memory checked out ** using [sqlite3_malloc()], either directly or indirectly. The ** figure includes calls made to [sqlite3_malloc()] by the application ** and internal memory usage by the SQLite library. Scratch memory ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in ** this parameter. The amount returned is the sum of the allocation ** sizes as reported by the xSize method in [sqlite3_mem_methods].
)^ ** ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(
SQLITE_STATUS_MALLOC_SIZE
**
This parameter records the largest memory allocation request ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their ** internal equivalents). Only the value returned in the ** *pHighwater parameter to [sqlite3_status()] is of interest. ** The value written into the *pCurrent parameter is undefined.
)^ ** ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(
SQLITE_STATUS_MALLOC_COUNT
**
This parameter records the number of separate memory allocations ** currently checked out.
)^ ** ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(
SQLITE_STATUS_PAGECACHE_USED
**
This parameter returns the number of pages used out of the ** [pagecache memory allocator] that was configured using ** [SQLITE_CONFIG_PAGECACHE]. The ** value returned is in pages, not in bytes.
)^ ** ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] ** ^(
SQLITE_STATUS_PAGECACHE_OVERFLOW
**
This parameter returns the number of bytes of page cache ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] ** buffer and where forced to overflow to [sqlite3_malloc()]. The ** returned value includes allocations that overflowed because they ** where too large (they were larger than the "sz" parameter to ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because ** no space was left in the page cache.
)^ ** ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(
SQLITE_STATUS_PAGECACHE_SIZE
**
This parameter records the largest memory allocation request ** handed to [pagecache memory allocator]. Only the value returned in the ** *pHighwater parameter to [sqlite3_status()] is of interest. ** The value written into the *pCurrent parameter is undefined.
)^ ** ** [[SQLITE_STATUS_SCRATCH_USED]] ^(
SQLITE_STATUS_SCRATCH_USED
**
This parameter returns the number of allocations used out of the ** [scratch memory allocator] configured using ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not ** in bytes. Since a single thread may only have one scratch allocation ** outstanding at time, this parameter also reports the number of threads ** using scratch memory at the same time.
)^ ** ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(
SQLITE_STATUS_SCRATCH_OVERFLOW
**
This parameter returns the number of bytes of scratch memory ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] ** buffer and where forced to overflow to [sqlite3_malloc()]. The values ** returned include overflows because the requested allocation was too ** larger (that is, because the requested allocation was larger than the ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer ** slots were available. **
)^ ** ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(
SQLITE_STATUS_SCRATCH_SIZE
**
This parameter records the largest memory allocation request ** handed to [scratch memory allocator]. Only the value returned in the ** *pHighwater parameter to [sqlite3_status()] is of interest. ** The value written into the *pCurrent parameter is undefined.
)^ ** ** [[SQLITE_STATUS_PARSER_STACK]] ^(
SQLITE_STATUS_PARSER_STACK
**
This parameter records the deepest parser stack. It is only ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].
)^ **
** ** New status parameters may be added from time to time. */ #define SQLITE_STATUS_MEMORY_USED 0 #define SQLITE_STATUS_PAGECACHE_USED 1 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 #define SQLITE_STATUS_SCRATCH_USED 3 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 #define SQLITE_STATUS_MALLOC_SIZE 5 #define SQLITE_STATUS_PARSER_STACK 6 #define SQLITE_STATUS_PAGECACHE_SIZE 7 #define SQLITE_STATUS_SCRATCH_SIZE 8 #define SQLITE_STATUS_MALLOC_COUNT 9 /* ** CAPI3REF: Database Connection Status ** ** ^This interface is used to retrieve runtime status information ** about a single [database connection]. ^The first argument is the ** database connection object to be interrogated. ^The second argument ** is an integer constant, taken from the set of ** [SQLITE_DBSTATUS options], that ** determines the parameter to interrogate. The set of ** [SQLITE_DBSTATUS options] is likely ** to grow in future releases of SQLite. ** ** ^The current value of the requested parameter is written into *pCur ** and the highest instantaneous value is written into *pHiwtr. ^If ** the resetFlg is true, then the highest instantaneous value is ** reset back down to the current value. ** ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a ** non-zero [error code] on failure. ** ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. */ SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); /* ** CAPI3REF: Status Parameters for database connections ** KEYWORDS: {SQLITE_DBSTATUS options} ** ** These constants are the available integer "verbs" that can be passed as ** the second argument to the [sqlite3_db_status()] interface. ** ** New verbs may be added in future releases of SQLite. Existing verbs ** might be discontinued. Applications should check the return code from ** [sqlite3_db_status()] to make sure that the call worked. ** The [sqlite3_db_status()] interface will return a non-zero error code ** if a discontinued or unsupported verb is invoked. ** **
** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(
SQLITE_DBSTATUS_LOOKASIDE_USED
**
This parameter returns the number of lookaside memory slots currently ** checked out.
)^ ** ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(
SQLITE_DBSTATUS_LOOKASIDE_HIT
**
This parameter returns the number malloc attempts that were ** satisfied using lookaside memory. Only the high-water value is meaningful; ** the current value is always zero.)^ ** ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] ** ^(
SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE
**
This parameter returns the number malloc attempts that might have ** been satisfied using lookaside memory but failed due to the amount of ** memory requested being larger than the lookaside slot size. ** Only the high-water value is meaningful; ** the current value is always zero.)^ ** ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] ** ^(
SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL
**
This parameter returns the number malloc attempts that might have ** been satisfied using lookaside memory but failed due to all lookaside ** memory already being in use. ** Only the high-water value is meaningful; ** the current value is always zero.)^ ** ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(
SQLITE_DBSTATUS_CACHE_USED
**
This parameter returns the approximate number of of bytes of heap ** memory used by all pager caches associated with the database connection.)^ ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. ** ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(
SQLITE_DBSTATUS_SCHEMA_USED
**
This parameter returns the approximate number of of bytes of heap ** memory used to store the schema for all databases associated ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ ** ^The full amount of memory used by the schemas is reported, even if the ** schema memory is shared with other database connections due to ** [shared cache mode] being enabled. ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. ** ** [[SQLITE_DBSTATUS_STMT_USED]] ^(
SQLITE_DBSTATUS_STMT_USED
**
This parameter returns the approximate number of of bytes of heap ** and lookaside memory used by all prepared statements associated with ** the database connection.)^ ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. **
** ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(
SQLITE_DBSTATUS_CACHE_HIT
**
This parameter returns the number of pager cache hits that have ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT ** is always 0. **
** ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(
SQLITE_DBSTATUS_CACHE_MISS
**
This parameter returns the number of pager cache misses that have ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS ** is always 0. **
** ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(
SQLITE_DBSTATUS_CACHE_WRITE
**
This parameter returns the number of dirty cache entries that have ** been written to disk. Specifically, the number of pages written to the ** wal file in wal mode databases, or the number of pages written to the ** database file in rollback mode databases. Any pages written as part of ** transaction rollback or database recovery operations are not included. ** If an IO or other error occurs while writing a page to disk, the effect ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. **
**
*/ #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 #define SQLITE_DBSTATUS_CACHE_USED 1 #define SQLITE_DBSTATUS_SCHEMA_USED 2 #define SQLITE_DBSTATUS_STMT_USED 3 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 #define SQLITE_DBSTATUS_CACHE_HIT 7 #define SQLITE_DBSTATUS_CACHE_MISS 8 #define SQLITE_DBSTATUS_CACHE_WRITE 9 #define SQLITE_DBSTATUS_MAX 9 /* Largest defined DBSTATUS */ /* ** CAPI3REF: Prepared Statement Status ** ** ^(Each prepared statement maintains various ** [SQLITE_STMTSTATUS counters] that measure the number ** of times it has performed specific operations.)^ These counters can ** be used to monitor the performance characteristics of the prepared ** statements. For example, if the number of table steps greatly exceeds ** the number of table searches or result rows, that would tend to indicate ** that the prepared statement is using a full table scan rather than ** an index. ** ** ^(This interface is used to retrieve and reset counter values from ** a [prepared statement]. The first argument is the prepared statement ** object to be interrogated. The second argument ** is an integer code for a specific [SQLITE_STMTSTATUS counter] ** to be interrogated.)^ ** ^The current value of the requested counter is returned. ** ^If the resetFlg is true, then the counter is reset to zero after this ** interface call returns. ** ** See also: [sqlite3_status()] and [sqlite3_db_status()]. */ SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); /* ** CAPI3REF: Status Parameters for prepared statements ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} ** ** These preprocessor macros define integer codes that name counter ** values associated with the [sqlite3_stmt_status()] interface. ** The meanings of the various counters are as follows: ** **
** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]]
SQLITE_STMTSTATUS_FULLSCAN_STEP
**
^This is the number of times that SQLite has stepped forward in ** a table as part of a full table scan. Large numbers for this counter ** may indicate opportunities for performance improvement through ** careful use of indices.
** ** [[SQLITE_STMTSTATUS_SORT]]
SQLITE_STMTSTATUS_SORT
**
^This is the number of sort operations that have occurred. ** A non-zero value in this counter may indicate an opportunity to ** improvement performance through careful use of indices.
** ** [[SQLITE_STMTSTATUS_AUTOINDEX]]
SQLITE_STMTSTATUS_AUTOINDEX
**
^This is the number of rows inserted into transient indices that ** were created automatically in order to help joins run faster. ** A non-zero value in this counter may indicate an opportunity to ** improvement performance by adding permanent indices that do not ** need to be reinitialized each time the statement is run.
**
*/ #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 #define SQLITE_STMTSTATUS_SORT 2 #define SQLITE_STMTSTATUS_AUTOINDEX 3 /* ** CAPI3REF: Custom Page Cache Object ** ** The sqlite3_pcache type is opaque. It is implemented by ** the pluggable module. The SQLite core has no knowledge of ** its size or internal structure and never deals with the ** sqlite3_pcache object except by holding and passing pointers ** to the object. ** ** See [sqlite3_pcache_methods2] for additional information. */ typedef struct sqlite3_pcache sqlite3_pcache; /* ** CAPI3REF: Custom Page Cache Object ** ** The sqlite3_pcache_page object represents a single page in the ** page cache. The page cache will allocate instances of this ** object. Various methods of the page cache use pointers to instances ** of this object as parameters or as their return value. ** ** See [sqlite3_pcache_methods2] for additional information. */ typedef struct sqlite3_pcache_page sqlite3_pcache_page; struct sqlite3_pcache_page { void *pBuf; /* The content of the page */ void *pExtra; /* Extra information associated with the page */ }; /* ** CAPI3REF: Application Defined Page Cache. ** KEYWORDS: {page cache} ** ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can ** register an alternative page cache implementation by passing in an ** instance of the sqlite3_pcache_methods2 structure.)^ ** In many applications, most of the heap memory allocated by ** SQLite is used for the page cache. ** By implementing a ** custom page cache using this API, an application can better control ** the amount of memory consumed by SQLite, the way in which ** that memory is allocated and released, and the policies used to ** determine exactly which parts of a database file are cached and for ** how long. ** ** The alternative page cache mechanism is an ** extreme measure that is only needed by the most demanding applications. ** The built-in page cache is recommended for most uses. ** ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an ** internal buffer by SQLite within the call to [sqlite3_config]. Hence ** the application may discard the parameter after the call to ** [sqlite3_config()] returns.)^ ** ** [[the xInit() page cache method]] ** ^(The xInit() method is called once for each effective ** call to [sqlite3_initialize()])^ ** (usually only once during the lifetime of the process). ^(The xInit() ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ ** The intent of the xInit() method is to set up global data structures ** required by the custom page cache implementation. ** ^(If the xInit() method is NULL, then the ** built-in default page cache is used instead of the application defined ** page cache.)^ ** ** [[the xShutdown() page cache method]] ** ^The xShutdown() method is called by [sqlite3_shutdown()]. ** It can be used to clean up ** any outstanding resources before process shutdown, if required. ** ^The xShutdown() method may be NULL. ** ** ^SQLite automatically serializes calls to the xInit method, ** so the xInit method need not be threadsafe. ^The ** xShutdown method is only called from [sqlite3_shutdown()] so it does ** not need to be threadsafe either. All other methods must be threadsafe ** in multithreaded applications. ** ** ^SQLite will never invoke xInit() more than once without an intervening ** call to xShutdown(). ** ** [[the xCreate() page cache methods]] ** ^SQLite invokes the xCreate() method to construct a new cache instance. ** SQLite will typically create one cache instance for each open database file, ** though this is not guaranteed. ^The ** first parameter, szPage, is the size in bytes of the pages that must ** be allocated by the cache. ^szPage will always a power of two. ^The ** second parameter szExtra is a number of bytes of extra storage ** associated with each page cache entry. ^The szExtra parameter will ** a number less than 250. SQLite will use the ** extra szExtra bytes on each page to store metadata about the underlying ** database page on disk. The value passed into szExtra depends ** on the SQLite version, the target platform, and how SQLite was compiled. ** ^The third argument to xCreate(), bPurgeable, is true if the cache being ** created will be used to cache database pages of a file stored on disk, or ** false if it is used for an in-memory database. The cache implementation ** does not have to do anything special based with the value of bPurgeable; ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will ** never invoke xUnpin() except to deliberately delete a page. ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to ** false will always have the "discard" flag set to true. ** ^Hence, a cache created with bPurgeable false will ** never contain any unpinned pages. ** ** [[the xCachesize() page cache method]] ** ^(The xCachesize() method may be called at any time by SQLite to set the ** suggested maximum cache-size (number of pages stored by) the cache ** instance passed as the first argument. This is the value configured using ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable ** parameter, the implementation is not required to do anything with this ** value; it is advisory only. ** ** [[the xPagecount() page cache methods]] ** The xPagecount() method must return the number of pages currently ** stored in the cache, both pinned and unpinned. ** ** [[the xFetch() page cache methods]] ** The xFetch() method locates a page in the cache and returns a pointer to ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. ** The pBuf element of the returned sqlite3_pcache_page object will be a ** pointer to a buffer of szPage bytes used to store the content of a ** single database page. The pExtra element of sqlite3_pcache_page will be ** a pointer to the szExtra bytes of extra storage that SQLite has requested ** for each entry in the page cache. ** ** The page to be fetched is determined by the key. ^The minimum key value ** is 1. After it has been retrieved using xFetch, the page is considered ** to be "pinned". ** ** If the requested page is already in the page cache, then the page cache ** implementation must return a pointer to the page buffer with its content ** intact. If the requested page is not already in the cache, then the ** cache implementation should use the value of the createFlag ** parameter to help it determined what action to take: ** ** **
createFlag Behaviour when page is not already in cache **
0 Do not allocate a new page. Return NULL. **
1 Allocate a new page if it easy and convenient to do so. ** Otherwise return NULL. **
2 Make every effort to allocate a new page. Only return ** NULL if allocating a new page is effectively impossible. **
** ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite ** will only use a createFlag of 2 after a prior call with a createFlag of 1 ** failed.)^ In between the to xFetch() calls, SQLite may ** attempt to unpin one or more cache pages by spilling the content of ** pinned pages to disk and synching the operating system disk cache. ** ** [[the xUnpin() page cache method]] ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page ** as its second argument. If the third parameter, discard, is non-zero, ** then the page must be evicted from the cache. ** ^If the discard parameter is ** zero, then the page may be discarded or retained at the discretion of ** page cache implementation. ^The page cache implementation ** may choose to evict unpinned pages at any time. ** ** The cache must not perform any reference counting. A single ** call to xUnpin() unpins the page regardless of the number of prior calls ** to xFetch(). ** ** [[the xRekey() page cache methods]] ** The xRekey() method is used to change the key value associated with the ** page passed as the second argument. If the cache ** previously contains an entry associated with newKey, it must be ** discarded. ^Any prior cache entry associated with newKey is guaranteed not ** to be pinned. ** ** When SQLite calls the xTruncate() method, the cache must discard all ** existing cache entries with page numbers (keys) greater than or equal ** to the value of the iLimit parameter passed to xTruncate(). If any ** of these pages are pinned, they are implicitly unpinned, meaning that ** they can be safely discarded. ** ** [[the xDestroy() page cache method]] ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). ** All resources associated with the specified cache should be freed. ^After ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 ** functions. ** ** [[the xShrink() page cache method]] ** ^SQLite invokes the xShrink() method when it wants the page cache to ** free up as much of heap memory as possible. The page cache implementation ** is not obligated to free any memory, but well-behaved implementations should ** do their best. */ typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; struct sqlite3_pcache_methods2 { int iVersion; void *pArg; int (*xInit)(void*); void (*xShutdown)(void*); sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); void (*xCachesize)(sqlite3_pcache*, int nCachesize); int (*xPagecount)(sqlite3_pcache*); sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, unsigned oldKey, unsigned newKey); void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); void (*xDestroy)(sqlite3_pcache*); void (*xShrink)(sqlite3_pcache*); }; /* ** This is the obsolete pcache_methods object that has now been replaced ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is ** retained in the header file for backwards compatibility only. */ typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; struct sqlite3_pcache_methods { void *pArg; int (*xInit)(void*); void (*xShutdown)(void*); sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); void (*xCachesize)(sqlite3_pcache*, int nCachesize); int (*xPagecount)(sqlite3_pcache*); void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); void (*xUnpin)(sqlite3_pcache*, void*, int discard); void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); void (*xDestroy)(sqlite3_pcache*); }; /* ** CAPI3REF: Online Backup Object ** ** The sqlite3_backup object records state information about an ongoing ** online backup operation. ^The sqlite3_backup object is created by ** a call to [sqlite3_backup_init()] and is destroyed by a call to ** [sqlite3_backup_finish()]. ** ** See Also: [Using the SQLite Online Backup API] */ typedef struct sqlite3_backup sqlite3_backup; /* ** CAPI3REF: Online Backup API. ** ** The backup API copies the content of one database into another. ** It is useful either for creating backups of databases or ** for copying in-memory databases to or from persistent files. ** ** See Also: [Using the SQLite Online Backup API] ** ** ^SQLite holds a write transaction open on the destination database file ** for the duration of the backup operation. ** ^The source database is read-locked only while it is being read; ** it is not locked continuously for the entire backup operation. ** ^Thus, the backup may be performed on a live source database without ** preventing other database connections from ** reading or writing to the source database while the backup is underway. ** ** ^(To perform a backup operation: **
    **
  1. sqlite3_backup_init() is called once to initialize the ** backup, **
  2. sqlite3_backup_step() is called one or more times to transfer ** the data between the two databases, and finally **
  3. sqlite3_backup_finish() is called to release all resources ** associated with the backup operation. **
)^ ** There should be exactly one call to sqlite3_backup_finish() for each ** successful call to sqlite3_backup_init(). ** ** [[sqlite3_backup_init()]] sqlite3_backup_init() ** ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the ** [database connection] associated with the destination database ** and the database name, respectively. ** ^The database name is "main" for the main database, "temp" for the ** temporary database, or the name specified after the AS keyword in ** an [ATTACH] statement for an attached database. ** ^The S and M arguments passed to ** sqlite3_backup_init(D,N,S,M) identify the [database connection] ** and database name of the source database, respectively. ** ^The source and destination [database connections] (parameters S and D) ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with ** an error. ** ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is ** returned and an error code and error message are stored in the ** destination [database connection] D. ** ^The error code and message for the failed call to sqlite3_backup_init() ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or ** [sqlite3_errmsg16()] functions. ** ^A successful call to sqlite3_backup_init() returns a pointer to an ** [sqlite3_backup] object. ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and ** sqlite3_backup_finish() functions to perform the specified backup ** operation. ** ** [[sqlite3_backup_step()]] sqlite3_backup_step() ** ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between ** the source and destination databases specified by [sqlite3_backup] object B. ** ^If N is negative, all remaining source pages are copied. ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there ** are still more pages to be copied, then the function returns [SQLITE_OK]. ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages ** from source to destination, then it returns [SQLITE_DONE]. ** ^If an error occurs while running sqlite3_backup_step(B,N), ** then an [error code] is returned. ^As well as [SQLITE_OK] and ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. ** ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if **
    **
  1. the destination database was opened read-only, or **
  2. the destination database is using write-ahead-log journaling ** and the destination and source page sizes differ, or **
  3. the destination database is an in-memory database and the ** destination and source page sizes differ. **
)^ ** ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then ** the [sqlite3_busy_handler | busy-handler function] ** is invoked (if one is specified). ^If the ** busy-handler returns non-zero before the lock is available, then ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to ** sqlite3_backup_step() can be retried later. ^If the source ** [database connection] ** is being used to write to the source database when sqlite3_backup_step() ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this ** case the call to sqlite3_backup_step() can be retried later on. ^(If ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or ** [SQLITE_READONLY] is returned, then ** there is no point in retrying the call to sqlite3_backup_step(). These ** errors are considered fatal.)^ The application must accept ** that the backup operation has failed and pass the backup operation handle ** to the sqlite3_backup_finish() to release associated resources. ** ** ^The first call to sqlite3_backup_step() obtains an exclusive lock ** on the destination file. ^The exclusive lock is not released until either ** sqlite3_backup_finish() is called or the backup operation is complete ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to ** sqlite3_backup_step() obtains a [shared lock] on the source database that ** lasts for the duration of the sqlite3_backup_step() call. ** ^Because the source database is not locked between calls to ** sqlite3_backup_step(), the source database may be modified mid-way ** through the backup process. ^If the source database is modified by an ** external process or via a database connection other than the one being ** used by the backup operation, then the backup will be automatically ** restarted by the next call to sqlite3_backup_step(). ^If the source ** database is modified by the using the same database connection as is used ** by the backup operation, then the backup database is automatically ** updated at the same time. ** ** [[sqlite3_backup_finish()]] sqlite3_backup_finish() ** ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the ** application wishes to abandon the backup operation, the application ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). ** ^The sqlite3_backup_finish() interfaces releases all ** resources associated with the [sqlite3_backup] object. ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any ** active write-transaction on the destination database is rolled back. ** The [sqlite3_backup] object is invalid ** and may not be used following a call to sqlite3_backup_finish(). ** ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no ** sqlite3_backup_step() errors occurred, regardless or whether or not ** sqlite3_backup_step() completed. ** ^If an out-of-memory condition or IO error occurred during any prior ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then ** sqlite3_backup_finish() returns the corresponding [error code]. ** ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() ** is not a permanent error and does not affect the return value of ** sqlite3_backup_finish(). ** ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] ** sqlite3_backup_remaining() and sqlite3_backup_pagecount() ** ** ^Each call to sqlite3_backup_step() sets two values inside ** the [sqlite3_backup] object: the number of pages still to be backed ** up and the total number of pages in the source database file. ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces ** retrieve these two values, respectively. ** ** ^The values returned by these functions are only updated by ** sqlite3_backup_step(). ^If the source database is modified during a backup ** operation, then the values are not updated to account for any extra ** pages that need to be updated or the size of the source database file ** changing. ** ** Concurrent Usage of Database Handles ** ** ^The source [database connection] may be used by the application for other ** purposes while a backup operation is underway or being initialized. ** ^If SQLite is compiled and configured to support threadsafe database ** connections, then the source database connection may be used concurrently ** from within other threads. ** ** However, the application must guarantee that the destination ** [database connection] is not passed to any other API (by any thread) after ** sqlite3_backup_init() is called and before the corresponding call to ** sqlite3_backup_finish(). SQLite does not currently check to see ** if the application incorrectly accesses the destination [database connection] ** and so no error code is reported, but the operations may malfunction ** nevertheless. Use of the destination database connection while a ** backup is in progress might also also cause a mutex deadlock. ** ** If running in [shared cache mode], the application must ** guarantee that the shared cache used by the destination database ** is not accessed while the backup is running. In practice this means ** that the application must guarantee that the disk file being ** backed up to is not accessed by any connection within the process, ** not just the specific connection that was passed to sqlite3_backup_init(). ** ** The [sqlite3_backup] object itself is partially threadsafe. Multiple ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() ** APIs are not strictly speaking threadsafe. If they are invoked at the ** same time as another thread is invoking sqlite3_backup_step() it is ** possible that they return invalid values. */ SQLITE_API sqlite3_backup *sqlite3_backup_init( sqlite3 *pDest, /* Destination database handle */ const char *zDestName, /* Destination database name */ sqlite3 *pSource, /* Source database handle */ const char *zSourceName /* Source database name */ ); SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); /* ** CAPI3REF: Unlock Notification ** ** ^When running in shared-cache mode, a database operation may fail with ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or ** individual tables within the shared-cache cannot be obtained. See ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. ** ^This API may be used to register a callback that SQLite will invoke ** when the connection currently holding the required lock relinquishes it. ** ^This API is only available if the library was compiled with the ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. ** ** See Also: [Using the SQLite Unlock Notification Feature]. ** ** ^Shared-cache locks are released when a database connection concludes ** its current transaction, either by committing it or rolling it back. ** ** ^When a connection (known as the blocked connection) fails to obtain a ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the ** identity of the database connection (the blocking connection) that ** has locked the required resource is stored internally. ^After an ** application receives an SQLITE_LOCKED error, it may call the ** sqlite3_unlock_notify() method with the blocked connection handle as ** the first argument to register for a callback that will be invoked ** when the blocking connections current transaction is concluded. ^The ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] ** call that concludes the blocking connections transaction. ** ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, ** there is a chance that the blocking connection will have already ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. ** If this happens, then the specified callback is invoked immediately, ** from within the call to sqlite3_unlock_notify().)^ ** ** ^If the blocked connection is attempting to obtain a write-lock on a ** shared-cache table, and more than one other connection currently holds ** a read-lock on the same table, then SQLite arbitrarily selects one of ** the other connections to use as the blocking connection. ** ** ^(There may be at most one unlock-notify callback registered by a ** blocked connection. If sqlite3_unlock_notify() is called when the ** blocked connection already has a registered unlock-notify callback, ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is ** called with a NULL pointer as its second argument, then any existing ** unlock-notify callback is canceled. ^The blocked connections ** unlock-notify callback may also be canceled by closing the blocked ** connection using [sqlite3_close()]. ** ** The unlock-notify callback is not reentrant. If an application invokes ** any sqlite3_xxx API functions from within an unlock-notify callback, a ** crash or deadlock may be the result. ** ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always ** returns SQLITE_OK. ** ** Callback Invocation Details ** ** When an unlock-notify callback is registered, the application provides a ** single void* pointer that is passed to the callback when it is invoked. ** However, the signature of the callback function allows SQLite to pass ** it an array of void* context pointers. The first argument passed to ** an unlock-notify callback is a pointer to an array of void* pointers, ** and the second is the number of entries in the array. ** ** When a blocking connections transaction is concluded, there may be ** more than one blocked connection that has registered for an unlock-notify ** callback. ^If two or more such blocked connections have specified the ** same callback function, then instead of invoking the callback function ** multiple times, it is invoked once with the set of void* context pointers ** specified by the blocked connections bundled together into an array. ** This gives the application an opportunity to prioritize any actions ** related to the set of unblocked database connections. ** ** Deadlock Detection ** ** Assuming that after registering for an unlock-notify callback a ** database waits for the callback to be issued before taking any further ** action (a reasonable assumption), then using this API may cause the ** application to deadlock. For example, if connection X is waiting for ** connection Y's transaction to be concluded, and similarly connection ** Y is waiting on connection X's transaction, then neither connection ** will proceed and the system may remain deadlocked indefinitely. ** ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock ** detection. ^If a given call to sqlite3_unlock_notify() would put the ** system in a deadlocked state, then SQLITE_LOCKED is returned and no ** unlock-notify callback is registered. The system is said to be in ** a deadlocked state if connection A has registered for an unlock-notify ** callback on the conclusion of connection B's transaction, and connection ** B has itself registered for an unlock-notify callback when connection ** A's transaction is concluded. ^Indirect deadlock is also detected, so ** the system is also considered to be deadlocked if connection B has ** registered for an unlock-notify callback on the conclusion of connection ** C's transaction, where connection C is waiting on connection A. ^Any ** number of levels of indirection are allowed. ** ** The "DROP TABLE" Exception ** ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost ** always appropriate to call sqlite3_unlock_notify(). There is however, ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, ** SQLite checks if there are any currently executing SELECT statements ** that belong to the same connection. If there are, SQLITE_LOCKED is ** returned. In this case there is no "blocking connection", so invoking ** sqlite3_unlock_notify() results in the unlock-notify callback being ** invoked immediately. If the application then re-attempts the "DROP TABLE" ** or "DROP INDEX" query, an infinite loop might be the result. ** ** One way around this problem is to check the extended error code returned ** by an sqlite3_step() call. ^(If there is a blocking connection, then the ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in ** the special "DROP TABLE/INDEX" case, the extended error code is just ** SQLITE_LOCKED.)^ */ SQLITE_API int sqlite3_unlock_notify( sqlite3 *pBlocked, /* Waiting connection */ void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ void *pNotifyArg /* Argument to pass to xNotify */ ); /* ** CAPI3REF: String Comparison ** ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications ** and extensions to compare the contents of two buffers containing UTF-8 ** strings in a case-independent fashion, using the same definition of "case ** independence" that SQLite uses internally when comparing identifiers. */ SQLITE_API int sqlite3_stricmp(const char *, const char *); SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); /* ** CAPI3REF: Error Logging Interface ** ** ^The [sqlite3_log()] interface writes a message into the error log ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. ** ^If logging is enabled, the zFormat string and subsequent arguments are ** used with [sqlite3_snprintf()] to generate the final output string. ** ** The sqlite3_log() interface is intended for use by extensions such as ** virtual tables, collating functions, and SQL functions. While there is ** nothing to prevent an application from calling sqlite3_log(), doing so ** is considered bad form. ** ** The zFormat string must not be NULL. ** ** To avoid deadlocks and other threading problems, the sqlite3_log() routine ** will not use dynamically allocated memory. The log message is stored in ** a fixed-length buffer on the stack. If the log message is longer than ** a few hundred characters, it will be truncated to the length of the ** buffer. */ SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); /* ** CAPI3REF: Write-Ahead Log Commit Hook ** ** ^The [sqlite3_wal_hook()] function is used to register a callback that ** will be invoked each time a database connection commits data to a ** [write-ahead log] (i.e. whenever a transaction is committed in ** [journal_mode | journal_mode=WAL mode]). ** ** ^The callback is invoked by SQLite after the commit has taken place and ** the associated write-lock on the database released, so the implementation ** may read, write or [checkpoint] the database as required. ** ** ^The first parameter passed to the callback function when it is invoked ** is a copy of the third parameter passed to sqlite3_wal_hook() when ** registering the callback. ^The second is a copy of the database handle. ** ^The third parameter is the name of the database that was written to - ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter ** is the number of pages currently in the write-ahead log file, ** including those that were just committed. ** ** The callback function should normally return [SQLITE_OK]. ^If an error ** code is returned, that error will propagate back up through the ** SQLite code base to cause the statement that provoked the callback ** to report an error, though the commit will have still occurred. If the ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value ** that does not correspond to any valid SQLite error code, the results ** are undefined. ** ** A single database handle may have at most a single write-ahead log callback ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any ** previously registered write-ahead log callback. ^Note that the ** [sqlite3_wal_autocheckpoint()] interface and the ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will ** those overwrite any prior [sqlite3_wal_hook()] settings. */ SQLITE_API void *sqlite3_wal_hook( sqlite3*, int(*)(void *,sqlite3*,const char*,int), void* ); /* ** CAPI3REF: Configure an auto-checkpoint ** ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around ** [sqlite3_wal_hook()] that causes any database on [database connection] D ** to automatically [checkpoint] ** after committing a transaction if there are N or ** more frames in the [write-ahead log] file. ^Passing zero or ** a negative value as the nFrame parameter disables automatic ** checkpoints entirely. ** ** ^The callback registered by this function replaces any existing callback ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism ** configured by this function. ** ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface ** from SQL. ** ** ^Every new [database connection] defaults to having the auto-checkpoint ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] ** pages. The use of this interface ** is only necessary if the default setting is found to be suboptimal ** for a particular application. */ SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); /* ** CAPI3REF: Checkpoint a database ** ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X ** on [database connection] D to be [checkpointed]. ^If X is NULL or an ** empty string, then a checkpoint is run on all databases of ** connection D. ^If the database connection D is not in ** [WAL | write-ahead log mode] then this interface is a harmless no-op. ** ** ^The [wal_checkpoint pragma] can be used to invoke this interface ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the ** [wal_autocheckpoint pragma] can be used to cause this interface to be ** run whenever the WAL reaches a certain size threshold. ** ** See also: [sqlite3_wal_checkpoint_v2()] */ SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); /* ** CAPI3REF: Checkpoint a database ** ** Run a checkpoint operation on WAL database zDb attached to database ** handle db. The specific operation is determined by the value of the ** eMode parameter: ** **
**
SQLITE_CHECKPOINT_PASSIVE
** Checkpoint as many frames as possible without waiting for any database ** readers or writers to finish. Sync the db file if all frames in the log ** are checkpointed. This mode is the same as calling ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. ** **
SQLITE_CHECKPOINT_FULL
** This mode blocks (calls the busy-handler callback) until there is no ** database writer and all readers are reading from the most recent database ** snapshot. It then checkpoints all frames in the log file and syncs the ** database file. This call blocks database writers while it is running, ** but not database readers. ** **
SQLITE_CHECKPOINT_RESTART
** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after ** checkpointing the log file it blocks (calls the busy-handler callback) ** until all readers are reading from the database file only. This ensures ** that the next client to write to the database file restarts the log file ** from the beginning. This call blocks database writers while it is running, ** but not database readers. **
** ** If pnLog is not NULL, then *pnLog is set to the total number of frames in ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to ** the total number of checkpointed frames (including any that were already ** checkpointed when this function is called). *pnLog and *pnCkpt may be ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. ** If no values are available because of an error, they are both set to -1 ** before returning to communicate this to the caller. ** ** All calls obtain an exclusive "checkpoint" lock on the database file. If ** any other process is running a checkpoint operation at the same time, the ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a ** busy-handler configured, it will not be invoked in this case. ** ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive ** "writer" lock on the database file. If the writer lock cannot be obtained ** immediately, and a busy-handler is configured, it is invoked and the writer ** lock retried until either the busy-handler returns 0 or the lock is ** successfully obtained. The busy-handler is also invoked while waiting for ** database readers as described above. If the busy-handler returns 0 before ** the writer lock is obtained or while waiting for database readers, the ** checkpoint operation proceeds from that point in the same way as ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible ** without blocking any further. SQLITE_BUSY is returned in this case. ** ** If parameter zDb is NULL or points to a zero length string, then the ** specified operation is attempted on all WAL databases. In this case the ** values written to output parameters *pnLog and *pnCkpt are undefined. If ** an SQLITE_BUSY error is encountered when processing one or more of the ** attached WAL databases, the operation is still attempted on any remaining ** attached databases and SQLITE_BUSY is returned to the caller. If any other ** error occurs while processing an attached database, processing is abandoned ** and the error code returned to the caller immediately. If no error ** (SQLITE_BUSY or otherwise) is encountered while processing the attached ** databases, SQLITE_OK is returned. ** ** If database zDb is the name of an attached database that is not in WAL ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If ** zDb is not NULL (or a zero length string) and is not the name of any ** attached database, SQLITE_ERROR is returned to the caller. */ SQLITE_API int sqlite3_wal_checkpoint_v2( sqlite3 *db, /* Database handle */ const char *zDb, /* Name of attached database (or NULL) */ int eMode, /* SQLITE_CHECKPOINT_* value */ int *pnLog, /* OUT: Size of WAL log in frames */ int *pnCkpt /* OUT: Total number of frames checkpointed */ ); /* ** CAPI3REF: Checkpoint operation parameters ** ** These constants can be used as the 3rd parameter to ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] ** documentation for additional information about the meaning and use of ** each of these values. */ #define SQLITE_CHECKPOINT_PASSIVE 0 #define SQLITE_CHECKPOINT_FULL 1 #define SQLITE_CHECKPOINT_RESTART 2 /* ** CAPI3REF: Virtual Table Interface Configuration ** ** This function may be called by either the [xConnect] or [xCreate] method ** of a [virtual table] implementation to configure ** various facets of the virtual table interface. ** ** If this interface is invoked outside the context of an xConnect or ** xCreate virtual table method then the behavior is undefined. ** ** At present, there is only one option that may be configured using ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options ** may be added in the future. */ SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); /* ** CAPI3REF: Virtual Table Configuration Options ** ** These macros define the various options to the ** [sqlite3_vtab_config()] interface that [virtual table] implementations ** can use to customize and optimize their behavior. ** **
**
SQLITE_VTAB_CONSTRAINT_SUPPORT **
Calls of the form ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, ** where X is an integer. If X is zero, then the [virtual table] whose ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not ** support constraints. In this configuration (which is the default) if ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been ** specified as part of the users SQL statement, regardless of the actual ** ON CONFLICT mode specified. ** ** If X is non-zero, then the virtual table implementation guarantees ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before ** any modifications to internal or persistent data structures have been made. ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite ** is able to roll back a statement or database transaction, and abandon ** or continue processing the current SQL statement as appropriate. ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode ** had been ABORT. ** ** Virtual table implementations that are required to handle OR REPLACE ** must do so within the [xUpdate] method. If a call to the ** [sqlite3_vtab_on_conflict()] function indicates that the current ON ** CONFLICT policy is REPLACE, the virtual table implementation should ** silently replace the appropriate rows within the xUpdate callback and ** return SQLITE_OK. Or, if this is not possible, it may return ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT ** constraint handling. **
*/ #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 /* ** CAPI3REF: Determine The Virtual Table Conflict Policy ** ** This function may only be called from within a call to the [xUpdate] method ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode ** of the SQL statement that triggered the call to the [xUpdate] method of the ** [virtual table]. */ SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); /* ** CAPI3REF: Conflict resolution modes ** ** These constants are returned by [sqlite3_vtab_on_conflict()] to ** inform a [virtual table] implementation what the [ON CONFLICT] mode ** is for the SQL statement being evaluated. ** ** Note that the [SQLITE_IGNORE] constant is also used as a potential ** return value from the [sqlite3_set_authorizer()] callback and that ** [SQLITE_ABORT] is also a [result code]. */ #define SQLITE_ROLLBACK 1 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ #define SQLITE_FAIL 3 /* #define SQLITE_ABORT 4 // Also an error code */ #define SQLITE_REPLACE 5 /* ** Undo the hack that converts floating point types to integer for ** builds on processors without floating point support. */ #ifdef SQLITE_OMIT_FLOATING_POINT # undef double #endif #if 0 } /* End of the 'extern "C"' block */ #endif #endif /* ** 2010 August 30 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* */ #ifndef _SQLITE3RTREE_H_ #define _SQLITE3RTREE_H_ #if 0 extern "C" { #endif typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; /* ** Register a geometry callback named zGeom that can be used as part of an ** R-Tree geometry query as follows: ** ** SELECT ... FROM WHERE MATCH $zGeom(... params ...) */ SQLITE_API int sqlite3_rtree_geometry_callback( sqlite3 *db, const char *zGeom, #ifdef SQLITE_RTREE_INT_ONLY int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes), #else int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes), #endif void *pContext ); /* ** A pointer to a structure of the following type is passed as the first ** argument to callbacks registered using rtree_geometry_callback(). */ struct sqlite3_rtree_geometry { void *pContext; /* Copy of pContext passed to s_r_g_c() */ int nParam; /* Size of array aParam[] */ double *aParam; /* Parameters passed to SQL geom function */ void *pUser; /* Callback implementation user data */ void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ }; #if 0 } /* end of the 'extern "C"' block */ #endif #endif /* ifndef _SQLITE3RTREE_H_ */ /************** End of sqlite3.h *********************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ /************** Include hash.h in the middle of sqliteInt.h ******************/ /************** Begin file hash.h ********************************************/ /* ** 2001 September 22 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This is the header file for the generic hash-table implemenation ** used in SQLite. */ #ifndef _SQLITE_HASH_H_ #define _SQLITE_HASH_H_ /* Forward declarations of structures. */ typedef struct Hash Hash; typedef struct HashElem HashElem; /* A complete hash table is an instance of the following structure. ** The internals of this structure are intended to be opaque -- client ** code should not attempt to access or modify the fields of this structure ** directly. Change this structure only by using the routines below. ** However, some of the "procedures" and "functions" for modifying and ** accessing this structure are really macros, so we can't really make ** this structure opaque. ** ** All elements of the hash table are on a single doubly-linked list. ** Hash.first points to the head of this list. ** ** There are Hash.htsize buckets. Each bucket points to a spot in ** the global doubly-linked list. The contents of the bucket are the ** element pointed to plus the next _ht.count-1 elements in the list. ** ** Hash.htsize and Hash.ht may be zero. In that case lookup is done ** by a linear search of the global list. For small tables, the ** Hash.ht table is never allocated because if there are few elements ** in the table, it is faster to do a linear search than to manage ** the hash table. */ struct Hash { unsigned int htsize; /* Number of buckets in the hash table */ unsigned int count; /* Number of entries in this table */ HashElem *first; /* The first element of the array */ struct _ht { /* the hash table */ int count; /* Number of entries with this hash */ HashElem *chain; /* Pointer to first entry with this hash */ } *ht; }; /* Each element in the hash table is an instance of the following ** structure. All elements are stored on a single doubly-linked list. ** ** Again, this structure is intended to be opaque, but it can't really ** be opaque because it is used by macros. */ struct HashElem { HashElem *next, *prev; /* Next and previous elements in the table */ void *data; /* Data associated with this element */ const char *pKey; int nKey; /* Key associated with this element */ }; /* ** Access routines. To delete, insert a NULL pointer. */ SQLITE_PRIVATE void sqlite3HashInit(Hash*); SQLITE_PRIVATE void *sqlite3HashInsert(Hash*, const char *pKey, int nKey, void *pData); SQLITE_PRIVATE void *sqlite3HashFind(const Hash*, const char *pKey, int nKey); SQLITE_PRIVATE void sqlite3HashClear(Hash*); /* ** Macros for looping over all elements of a hash table. The idiom is ** like this: ** ** Hash h; ** HashElem *p; ** ... ** for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){ ** SomeStructure *pData = sqliteHashData(p); ** // do something with pData ** } */ #define sqliteHashFirst(H) ((H)->first) #define sqliteHashNext(E) ((E)->next) #define sqliteHashData(E) ((E)->data) /* #define sqliteHashKey(E) ((E)->pKey) // NOT USED */ /* #define sqliteHashKeysize(E) ((E)->nKey) // NOT USED */ /* ** Number of entries in a hash table */ /* #define sqliteHashCount(H) ((H)->count) // NOT USED */ #endif /* _SQLITE_HASH_H_ */ /************** End of hash.h ************************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ /************** Include parse.h in the middle of sqliteInt.h *****************/ /************** Begin file parse.h *******************************************/ #define TK_SEMI 1 #define TK_EXPLAIN 2 #define TK_QUERY 3 #define TK_PLAN 4 #define TK_BEGIN 5 #define TK_TRANSACTION 6 #define TK_DEFERRED 7 #define TK_IMMEDIATE 8 #define TK_EXCLUSIVE 9 #define TK_COMMIT 10 #define TK_END 11 #define TK_ROLLBACK 12 #define TK_SAVEPOINT 13 #define TK_RELEASE 14 #define TK_TO 15 #define TK_TABLE 16 #define TK_CREATE 17 #define TK_IF 18 #define TK_NOT 19 #define TK_EXISTS 20 #define TK_TEMP 21 #define TK_LP 22 #define TK_RP 23 #define TK_AS 24 #define TK_COMMA 25 #define TK_ID 26 #define TK_INDEXED 27 #define TK_ABORT 28 #define TK_ACTION 29 #define TK_AFTER 30 #define TK_ANALYZE 31 #define TK_ASC 32 #define TK_ATTACH 33 #define TK_BEFORE 34 #define TK_BY 35 #define TK_CASCADE 36 #define TK_CAST 37 #define TK_COLUMNKW 38 #define TK_CONFLICT 39 #define TK_DATABASE 40 #define TK_DESC 41 #define TK_DETACH 42 #define TK_EACH 43 #define TK_FAIL 44 #define TK_FOR 45 #define TK_IGNORE 46 #define TK_INITIALLY 47 #define TK_INSTEAD 48 #define TK_LIKE_KW 49 #define TK_MATCH 50 #define TK_NO 51 #define TK_KEY 52 #define TK_OF 53 #define TK_OFFSET 54 #define TK_PRAGMA 55 #define TK_RAISE 56 #define TK_REPLACE 57 #define TK_RESTRICT 58 #define TK_ROW 59 #define TK_TRIGGER 60 #define TK_VACUUM 61 #define TK_VIEW 62 #define TK_VIRTUAL 63 #define TK_REINDEX 64 #define TK_RENAME 65 #define TK_CTIME_KW 66 #define TK_ANY 67 #define TK_OR 68 #define TK_AND 69 #define TK_IS 70 #define TK_BETWEEN 71 #define TK_IN 72 #define TK_ISNULL 73 #define TK_NOTNULL 74 #define TK_NE 75 #define TK_EQ 76 #define TK_GT 77 #define TK_LE 78 #define TK_LT 79 #define TK_GE 80 #define TK_ESCAPE 81 #define TK_BITAND 82 #define TK_BITOR 83 #define TK_LSHIFT 84 #define TK_RSHIFT 85 #define TK_PLUS 86 #define TK_MINUS 87 #define TK_STAR 88 #define TK_SLASH 89 #define TK_REM 90 #define TK_CONCAT 91 #define TK_COLLATE 92 #define TK_BITNOT 93 #define TK_STRING 94 #define TK_JOIN_KW 95 #define TK_CONSTRAINT 96 #define TK_DEFAULT 97 #define TK_NULL 98 #define TK_PRIMARY 99 #define TK_UNIQUE 100 #define TK_CHECK 101 #define TK_REFERENCES 102 #define TK_AUTOINCR 103 #define TK_ON 104 #define TK_INSERT 105 #define TK_DELETE 106 #define TK_UPDATE 107 #define TK_SET 108 #define TK_DEFERRABLE 109 #define TK_FOREIGN 110 #define TK_DROP 111 #define TK_UNION 112 #define TK_ALL 113 #define TK_EXCEPT 114 #define TK_INTERSECT 115 #define TK_SELECT 116 #define TK_DISTINCT 117 #define TK_DOT 118 #define TK_FROM 119 #define TK_JOIN 120 #define TK_USING 121 #define TK_ORDER 122 #define TK_GROUP 123 #define TK_HAVING 124 #define TK_LIMIT 125 #define TK_WHERE 126 #define TK_INTO 127 #define TK_VALUES 128 #define TK_INTEGER 129 #define TK_FLOAT 130 #define TK_BLOB 131 #define TK_REGISTER 132 #define TK_VARIABLE 133 #define TK_CASE 134 #define TK_WHEN 135 #define TK_THEN 136 #define TK_ELSE 137 #define TK_INDEX 138 #define TK_ALTER 139 #define TK_ADD 140 #define TK_TO_TEXT 141 #define TK_TO_BLOB 142 #define TK_TO_NUMERIC 143 #define TK_TO_INT 144 #define TK_TO_REAL 145 #define TK_ISNOT 146 #define TK_END_OF_FILE 147 #define TK_ILLEGAL 148 #define TK_SPACE 149 #define TK_UNCLOSED_STRING 150 #define TK_FUNCTION 151 #define TK_COLUMN 152 #define TK_AGG_FUNCTION 153 #define TK_AGG_COLUMN 154 #define TK_CONST_FUNC 155 #define TK_UMINUS 156 #define TK_UPLUS 157 /************** End of parse.h ***********************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ #include #include #include #include #include /* ** If compiling for a processor that lacks floating point support, ** substitute integer for floating-point */ #ifdef SQLITE_OMIT_FLOATING_POINT # define double sqlite_int64 # define float sqlite_int64 # define LONGDOUBLE_TYPE sqlite_int64 # ifndef SQLITE_BIG_DBL # define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50) # endif # define SQLITE_OMIT_DATETIME_FUNCS 1 # define SQLITE_OMIT_TRACE 1 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT # undef SQLITE_HAVE_ISNAN #endif #ifndef SQLITE_BIG_DBL # define SQLITE_BIG_DBL (1e99) #endif /* ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0 ** afterward. Having this macro allows us to cause the C compiler ** to omit code used by TEMP tables without messy #ifndef statements. */ #ifdef SQLITE_OMIT_TEMPDB #define OMIT_TEMPDB 1 #else #define OMIT_TEMPDB 0 #endif /* ** The "file format" number is an integer that is incremented whenever ** the VDBE-level file format changes. The following macros define the ** the default file format for new databases and the maximum file format ** that the library can read. */ #define SQLITE_MAX_FILE_FORMAT 4 #ifndef SQLITE_DEFAULT_FILE_FORMAT # define SQLITE_DEFAULT_FILE_FORMAT 4 #endif /* ** Determine whether triggers are recursive by default. This can be ** changed at run-time using a pragma. */ #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0 #endif /* ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified ** on the command-line */ #ifndef SQLITE_TEMP_STORE # define SQLITE_TEMP_STORE 1 #endif /* ** GCC does not define the offsetof() macro so we'll have to do it ** ourselves. */ #ifndef offsetof #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD)) #endif /* ** Check to see if this machine uses EBCDIC. (Yes, believe it or ** not, there are still machines out there that use EBCDIC.) */ #if 'A' == '\301' # define SQLITE_EBCDIC 1 #else # define SQLITE_ASCII 1 #endif /* ** Integers of known sizes. These typedefs might change for architectures ** where the sizes very. Preprocessor macros are available so that the ** types can be conveniently redefined at compile-type. Like this: ** ** cc '-DUINTPTR_TYPE=long long int' ... */ #ifndef UINT32_TYPE # ifdef HAVE_UINT32_T # define UINT32_TYPE uint32_t # else # define UINT32_TYPE unsigned int # endif #endif #ifndef UINT16_TYPE # ifdef HAVE_UINT16_T # define UINT16_TYPE uint16_t # else # define UINT16_TYPE unsigned short int # endif #endif #ifndef INT16_TYPE # ifdef HAVE_INT16_T # define INT16_TYPE int16_t # else # define INT16_TYPE short int # endif #endif #ifndef UINT8_TYPE # ifdef HAVE_UINT8_T # define UINT8_TYPE uint8_t # else # define UINT8_TYPE unsigned char # endif #endif #ifndef INT8_TYPE # ifdef HAVE_INT8_T # define INT8_TYPE int8_t # else # define INT8_TYPE signed char # endif #endif #ifndef LONGDOUBLE_TYPE # define LONGDOUBLE_TYPE long double #endif typedef sqlite_int64 i64; /* 8-byte signed integer */ typedef sqlite_uint64 u64; /* 8-byte unsigned integer */ typedef UINT32_TYPE u32; /* 4-byte unsigned integer */ typedef UINT16_TYPE u16; /* 2-byte unsigned integer */ typedef INT16_TYPE i16; /* 2-byte signed integer */ typedef UINT8_TYPE u8; /* 1-byte unsigned integer */ typedef INT8_TYPE i8; /* 1-byte signed integer */ /* ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value ** that can be stored in a u32 without loss of data. The value ** is 0x00000000ffffffff. But because of quirks of some compilers, we ** have to specify the value in the less intuitive manner shown: */ #define SQLITE_MAX_U32 ((((u64)1)<<32)-1) /* ** The datatype used to store estimates of the number of rows in a ** table or index. This is an unsigned integer type. For 99.9% of ** the world, a 32-bit integer is sufficient. But a 64-bit integer ** can be used at compile-time if desired. */ #ifdef SQLITE_64BIT_STATS typedef u64 tRowcnt; /* 64-bit only if requested at compile-time */ #else typedef u32 tRowcnt; /* 32-bit is the default */ #endif /* ** Macros to determine whether the machine is big or little endian, ** evaluated at runtime. */ #ifdef SQLITE_AMALGAMATION SQLITE_PRIVATE const int sqlite3one = 1; #else SQLITE_PRIVATE const int sqlite3one; #endif #if defined(i386) || defined(__i386__) || defined(_M_IX86)\ || defined(__x86_64) || defined(__x86_64__) # define SQLITE_BIGENDIAN 0 # define SQLITE_LITTLEENDIAN 1 # define SQLITE_UTF16NATIVE SQLITE_UTF16LE #else # define SQLITE_BIGENDIAN (*(char *)(&sqlite3one)==0) # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1) # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE) #endif /* ** Constants for the largest and smallest possible 64-bit signed integers. ** These macros are designed to work correctly on both 32-bit and 64-bit ** compilers. */ #define LARGEST_INT64 (0xffffffff|(((i64)0x7fffffff)<<32)) #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64) /* ** Round up a number to the next larger multiple of 8. This is used ** to force 8-byte alignment on 64-bit architectures. */ #define ROUND8(x) (((x)+7)&~7) /* ** Round down to the nearest multiple of 8 */ #define ROUNDDOWN8(x) ((x)&~7) /* ** Assert that the pointer X is aligned to an 8-byte boundary. This ** macro is used only within assert() to verify that the code gets ** all alignment restrictions correct. ** ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the ** underlying malloc() implemention might return us 4-byte aligned ** pointers. In that case, only verify 4-byte alignment. */ #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC # define EIGHT_BYTE_ALIGNMENT(X) ((((char*)(X) - (char*)0)&3)==0) #else # define EIGHT_BYTE_ALIGNMENT(X) ((((char*)(X) - (char*)0)&7)==0) #endif /* ** An instance of the following structure is used to store the busy-handler ** callback for a given sqlite handle. ** ** The sqlite.busyHandler member of the sqlite struct contains the busy ** callback for the database handle. Each pager opened via the sqlite ** handle is passed a pointer to sqlite.busyHandler. The busy-handler ** callback is currently invoked only from within pager.c. */ typedef struct BusyHandler BusyHandler; struct BusyHandler { int (*xFunc)(void *,int); /* The busy callback */ void *pArg; /* First arg to busy callback */ int nBusy; /* Incremented with each busy call */ }; /* ** Name of the master database table. The master database table ** is a special table that holds the names and attributes of all ** user tables and indices. */ #define MASTER_NAME "sqlite_master" #define TEMP_MASTER_NAME "sqlite_temp_master" /* ** The root-page of the master database table. */ #define MASTER_ROOT 1 /* ** The name of the schema table. */ #define SCHEMA_TABLE(x) ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME) /* ** A convenience macro that returns the number of elements in ** an array. */ #define ArraySize(X) ((int)(sizeof(X)/sizeof(X[0]))) /* ** The following value as a destructor means to use sqlite3DbFree(). ** The sqlite3DbFree() routine requires two parameters instead of the ** one parameter that destructors normally want. So we have to introduce ** this magic value that the code knows to handle differently. Any ** pointer will work here as long as it is distinct from SQLITE_STATIC ** and SQLITE_TRANSIENT. */ #define SQLITE_DYNAMIC ((sqlite3_destructor_type)sqlite3MallocSize) /* ** When SQLITE_OMIT_WSD is defined, it means that the target platform does ** not support Writable Static Data (WSD) such as global and static variables. ** All variables must either be on the stack or dynamically allocated from ** the heap. When WSD is unsupported, the variable declarations scattered ** throughout the SQLite code must become constants instead. The SQLITE_WSD ** macro is used for this purpose. And instead of referencing the variable ** directly, we use its constant as a key to lookup the run-time allocated ** buffer that holds real variable. The constant is also the initializer ** for the run-time allocated buffer. ** ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL ** macros become no-ops and have zero performance impact. */ #ifdef SQLITE_OMIT_WSD #define SQLITE_WSD const #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v))) #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config) SQLITE_API int sqlite3_wsd_init(int N, int J); SQLITE_API void *sqlite3_wsd_find(void *K, int L); #else #define SQLITE_WSD #define GLOBAL(t,v) v #define sqlite3GlobalConfig sqlite3Config #endif /* ** The following macros are used to suppress compiler warnings and to ** make it clear to human readers when a function parameter is deliberately ** left unused within the body of a function. This usually happens when ** a function is called via a function pointer. For example the ** implementation of an SQL aggregate step callback may not use the ** parameter indicating the number of arguments passed to the aggregate, ** if it knows that this is enforced elsewhere. ** ** When a function parameter is not used at all within the body of a function, ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer. ** However, these macros may also be used to suppress warnings related to ** parameters that may or may not be used depending on compilation options. ** For example those parameters only used in assert() statements. In these ** cases the parameters are named as per the usual conventions. */ #define UNUSED_PARAMETER(x) (void)(x) #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y) /* ** Forward references to structures */ typedef struct AggInfo AggInfo; typedef struct AuthContext AuthContext; typedef struct AutoincInfo AutoincInfo; typedef struct Bitvec Bitvec; typedef struct CollSeq CollSeq; typedef struct Column Column; typedef struct Db Db; typedef struct Schema Schema; typedef struct Expr Expr; typedef struct ExprList ExprList; typedef struct ExprSpan ExprSpan; typedef struct FKey FKey; typedef struct FuncDestructor FuncDestructor; typedef struct FuncDef FuncDef; typedef struct FuncDefHash FuncDefHash; typedef struct IdList IdList; typedef struct Index Index; typedef struct IndexSample IndexSample; typedef struct KeyClass KeyClass; typedef struct KeyInfo KeyInfo; typedef struct Lookaside Lookaside; typedef struct LookasideSlot LookasideSlot; typedef struct Module Module; typedef struct NameContext NameContext; typedef struct Parse Parse; typedef struct RowSet RowSet; typedef struct Savepoint Savepoint; typedef struct Select Select; typedef struct SrcList SrcList; typedef struct StrAccum StrAccum; typedef struct Table Table; typedef struct TableLock TableLock; typedef struct Token Token; typedef struct Trigger Trigger; typedef struct TriggerPrg TriggerPrg; typedef struct TriggerStep TriggerStep; typedef struct UnpackedRecord UnpackedRecord; typedef struct VTable VTable; typedef struct VtabCtx VtabCtx; typedef struct Walker Walker; typedef struct WherePlan WherePlan; typedef struct WhereInfo WhereInfo; typedef struct WhereLevel WhereLevel; /* ** Defer sourcing vdbe.h and btree.h until after the "u8" and ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque ** pointer types (i.e. FuncDef) defined above. */ /************** Include btree.h in the middle of sqliteInt.h *****************/ /************** Begin file btree.h *******************************************/ /* ** 2001 September 15 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This header file defines the interface that the sqlite B-Tree file ** subsystem. See comments in the source code for a detailed description ** of what each interface routine does. */ #ifndef _BTREE_H_ #define _BTREE_H_ /* TODO: This definition is just included so other modules compile. It ** needs to be revisited. */ #define SQLITE_N_BTREE_META 10 /* ** If defined as non-zero, auto-vacuum is enabled by default. Otherwise ** it must be turned on for each database using "PRAGMA auto_vacuum = 1". */ #ifndef SQLITE_DEFAULT_AUTOVACUUM #define SQLITE_DEFAULT_AUTOVACUUM 0 #endif #define BTREE_AUTOVACUUM_NONE 0 /* Do not do auto-vacuum */ #define BTREE_AUTOVACUUM_FULL 1 /* Do full auto-vacuum */ #define BTREE_AUTOVACUUM_INCR 2 /* Incremental vacuum */ /* ** Forward declarations of structure */ typedef struct Btree Btree; typedef struct BtCursor BtCursor; typedef struct BtShared BtShared; SQLITE_PRIVATE int sqlite3BtreeOpen( sqlite3_vfs *pVfs, /* VFS to use with this b-tree */ const char *zFilename, /* Name of database file to open */ sqlite3 *db, /* Associated database connection */ Btree **ppBtree, /* Return open Btree* here */ int flags, /* Flags */ int vfsFlags /* Flags passed through to VFS open */ ); /* The flags parameter to sqlite3BtreeOpen can be the bitwise or of the ** following values. ** ** NOTE: These values must match the corresponding PAGER_ values in ** pager.h. */ #define BTREE_OMIT_JOURNAL 1 /* Do not create or use a rollback journal */ #define BTREE_MEMORY 2 /* This is an in-memory DB */ #define BTREE_SINGLE 4 /* The file contains at most 1 b-tree */ #define BTREE_UNORDERED 8 /* Use of a hash implementation is OK */ SQLITE_PRIVATE int sqlite3BtreeClose(Btree*); SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree*,int); SQLITE_PRIVATE int sqlite3BtreeSetSafetyLevel(Btree*,int,int,int); SQLITE_PRIVATE int sqlite3BtreeSyncDisabled(Btree*); SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix); SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree*); SQLITE_PRIVATE int sqlite3BtreeMaxPageCount(Btree*,int); SQLITE_PRIVATE u32 sqlite3BtreeLastPage(Btree*); SQLITE_PRIVATE int sqlite3BtreeSecureDelete(Btree*,int); SQLITE_PRIVATE int sqlite3BtreeGetReserve(Btree*); SQLITE_PRIVATE int sqlite3BtreeSetAutoVacuum(Btree *, int); SQLITE_PRIVATE int sqlite3BtreeGetAutoVacuum(Btree *); SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree*,int); SQLITE_PRIVATE int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster); SQLITE_PRIVATE int sqlite3BtreeCommitPhaseTwo(Btree*, int); SQLITE_PRIVATE int sqlite3BtreeCommit(Btree*); SQLITE_PRIVATE int sqlite3BtreeRollback(Btree*,int); SQLITE_PRIVATE int sqlite3BtreeBeginStmt(Btree*,int); SQLITE_PRIVATE int sqlite3BtreeCreateTable(Btree*, int*, int flags); SQLITE_PRIVATE int sqlite3BtreeIsInTrans(Btree*); SQLITE_PRIVATE int sqlite3BtreeIsInReadTrans(Btree*); SQLITE_PRIVATE int sqlite3BtreeIsInBackup(Btree*); SQLITE_PRIVATE void *sqlite3BtreeSchema(Btree *, int, void(*)(void *)); SQLITE_PRIVATE int sqlite3BtreeSchemaLocked(Btree *pBtree); SQLITE_PRIVATE int sqlite3BtreeLockTable(Btree *pBtree, int iTab, u8 isWriteLock); SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *, int, int); SQLITE_PRIVATE const char *sqlite3BtreeGetFilename(Btree *); SQLITE_PRIVATE const char *sqlite3BtreeGetJournalname(Btree *); SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *, Btree *); SQLITE_PRIVATE int sqlite3BtreeIncrVacuum(Btree *); /* The flags parameter to sqlite3BtreeCreateTable can be the bitwise OR ** of the flags shown below. ** ** Every SQLite table must have either BTREE_INTKEY or BTREE_BLOBKEY set. ** With BTREE_INTKEY, the table key is a 64-bit integer and arbitrary data ** is stored in the leaves. (BTREE_INTKEY is used for SQL tables.) With ** BTREE_BLOBKEY, the key is an arbitrary BLOB and no content is stored ** anywhere - the key is the content. (BTREE_BLOBKEY is used for SQL ** indices.) */ #define BTREE_INTKEY 1 /* Table has only 64-bit signed integer keys */ #define BTREE_BLOBKEY 2 /* Table has keys only - no data */ SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree*, int, int*); SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree*, int, int*); SQLITE_PRIVATE void sqlite3BtreeTripAllCursors(Btree*, int); SQLITE_PRIVATE void sqlite3BtreeGetMeta(Btree *pBtree, int idx, u32 *pValue); SQLITE_PRIVATE int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value); /* ** The second parameter to sqlite3BtreeGetMeta or sqlite3BtreeUpdateMeta ** should be one of the following values. The integer values are assigned ** to constants so that the offset of the corresponding field in an ** SQLite database header may be found using the following formula: ** ** offset = 36 + (idx * 4) ** ** For example, the free-page-count field is located at byte offset 36 of ** the database file header. The incr-vacuum-flag field is located at ** byte offset 64 (== 36+4*7). */ #define BTREE_FREE_PAGE_COUNT 0 #define BTREE_SCHEMA_VERSION 1 #define BTREE_FILE_FORMAT 2 #define BTREE_DEFAULT_CACHE_SIZE 3 #define BTREE_LARGEST_ROOT_PAGE 4 #define BTREE_TEXT_ENCODING 5 #define BTREE_USER_VERSION 6 #define BTREE_INCR_VACUUM 7 SQLITE_PRIVATE int sqlite3BtreeCursor( Btree*, /* BTree containing table to open */ int iTable, /* Index of root page */ int wrFlag, /* 1 for writing. 0 for read-only */ struct KeyInfo*, /* First argument to compare function */ BtCursor *pCursor /* Space to write cursor structure */ ); SQLITE_PRIVATE int sqlite3BtreeCursorSize(void); SQLITE_PRIVATE void sqlite3BtreeCursorZero(BtCursor*); SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor*); SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked( BtCursor*, UnpackedRecord *pUnKey, i64 intKey, int bias, int *pRes ); SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor*, int*); SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor*); 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*); SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor*, int *pRes); SQLITE_PRIVATE int sqlite3BtreeKeySize(BtCursor*, i64 *pSize); SQLITE_PRIVATE int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*); SQLITE_PRIVATE const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt); SQLITE_PRIVATE const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt); SQLITE_PRIVATE int sqlite3BtreeDataSize(BtCursor*, u32 *pSize); SQLITE_PRIVATE int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*); SQLITE_PRIVATE void sqlite3BtreeSetCachedRowid(BtCursor*, sqlite3_int64); SQLITE_PRIVATE sqlite3_int64 sqlite3BtreeGetCachedRowid(BtCursor*); SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*); SQLITE_PRIVATE struct Pager *sqlite3BtreePager(Btree*); SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*); SQLITE_PRIVATE void sqlite3BtreeCacheOverflow(BtCursor *); SQLITE_PRIVATE void sqlite3BtreeClearCursor(BtCursor *); SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBt, int iVersion); #ifndef NDEBUG SQLITE_PRIVATE int sqlite3BtreeCursorIsValid(BtCursor*); #endif #ifndef SQLITE_OMIT_BTREECOUNT SQLITE_PRIVATE int sqlite3BtreeCount(BtCursor *, i64 *); #endif #ifdef SQLITE_TEST SQLITE_PRIVATE int sqlite3BtreeCursorInfo(BtCursor*, int*, int); SQLITE_PRIVATE void sqlite3BtreeCursorList(Btree*); #endif #ifndef SQLITE_OMIT_WAL SQLITE_PRIVATE int sqlite3BtreeCheckpoint(Btree*, int, int *, int *); #endif /* ** 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 #endif /* _BTREE_H_ */ /************** End of btree.h ***********************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ /************** Include vdbe.h in the middle of sqliteInt.h ******************/ /************** Begin file vdbe.h ********************************************/ /* ** 2001 September 15 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** Header file for the Virtual DataBase Engine (VDBE) ** ** This header defines the interface to the virtual database engine ** or VDBE. The VDBE implements an abstract machine that runs a ** simple program to access and modify the underlying database. */ #ifndef _SQLITE_VDBE_H_ #define _SQLITE_VDBE_H_ /* #include */ /* ** A single VDBE is an opaque structure named "Vdbe". Only routines ** in the source file sqliteVdbe.c are allowed to see the insides ** of this structure. */ typedef struct Vdbe Vdbe; /* ** The names of the following types declared in vdbeInt.h are required ** for the VdbeOp definition. */ typedef struct VdbeFunc VdbeFunc; typedef struct Mem Mem; typedef struct SubProgram SubProgram; /* ** A single instruction of the virtual machine has an opcode ** and as many as three operands. The instruction is recorded ** as an instance of the following structure: */ struct VdbeOp { u8 opcode; /* What operation to perform */ signed char p4type; /* One of the P4_xxx constants for p4 */ u8 opflags; /* Mask of the OPFLG_* flags in opcodes.h */ u8 p5; /* Fifth parameter is an unsigned character */ int p1; /* First operand */ int p2; /* Second parameter (often the jump destination) */ int p3; /* The third parameter */ union { /* fourth parameter */ int i; /* Integer value if p4type==P4_INT32 */ void *p; /* Generic pointer */ char *z; /* Pointer to data for string (char array) types */ i64 *pI64; /* Used when p4type is P4_INT64 */ double *pReal; /* Used when p4type is P4_REAL */ FuncDef *pFunc; /* Used when p4type is P4_FUNCDEF */ VdbeFunc *pVdbeFunc; /* Used when p4type is P4_VDBEFUNC */ CollSeq *pColl; /* Used when p4type is P4_COLLSEQ */ Mem *pMem; /* Used when p4type is P4_MEM */ VTable *pVtab; /* Used when p4type is P4_VTAB */ KeyInfo *pKeyInfo; /* Used when p4type is P4_KEYINFO */ int *ai; /* Used when p4type is P4_INTARRAY */ SubProgram *pProgram; /* Used when p4type is P4_SUBPROGRAM */ int (*xAdvance)(BtCursor *, int *); } p4; #ifdef SQLITE_DEBUG char *zComment; /* Comment to improve readability */ #endif #ifdef VDBE_PROFILE int cnt; /* Number of times this instruction was executed */ u64 cycles; /* Total time spent executing this instruction */ #endif }; typedef struct VdbeOp VdbeOp; /* ** A sub-routine used to implement a trigger program. */ struct SubProgram { VdbeOp *aOp; /* Array of opcodes for sub-program */ int nOp; /* Elements in aOp[] */ int nMem; /* Number of memory cells required */ int nCsr; /* Number of cursors required */ int nOnce; /* Number of OP_Once instructions */ void *token; /* id that may be used to recursive triggers */ SubProgram *pNext; /* Next sub-program already visited */ }; /* ** A smaller version of VdbeOp used for the VdbeAddOpList() function because ** it takes up less space. */ struct VdbeOpList { u8 opcode; /* What operation to perform */ signed char p1; /* First operand */ signed char p2; /* Second parameter (often the jump destination) */ signed char p3; /* Third parameter */ }; typedef struct VdbeOpList VdbeOpList; /* ** Allowed values of VdbeOp.p4type */ #define P4_NOTUSED 0 /* The P4 parameter is not used */ #define P4_DYNAMIC (-1) /* Pointer to a string obtained from sqliteMalloc() */ #define P4_STATIC (-2) /* Pointer to a static string */ #define P4_COLLSEQ (-4) /* P4 is a pointer to a CollSeq structure */ #define P4_FUNCDEF (-5) /* P4 is a pointer to a FuncDef structure */ #define P4_KEYINFO (-6) /* P4 is a pointer to a KeyInfo structure */ #define P4_VDBEFUNC (-7) /* P4 is a pointer to a VdbeFunc structure */ #define P4_MEM (-8) /* P4 is a pointer to a Mem* structure */ #define P4_TRANSIENT 0 /* P4 is a pointer to a transient string */ #define P4_VTAB (-10) /* P4 is a pointer to an sqlite3_vtab structure */ #define P4_MPRINTF (-11) /* P4 is a string obtained from sqlite3_mprintf() */ #define P4_REAL (-12) /* P4 is a 64-bit floating point value */ #define P4_INT64 (-13) /* P4 is a 64-bit signed integer */ #define P4_INT32 (-14) /* P4 is a 32-bit signed integer */ #define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */ #define P4_SUBPROGRAM (-18) /* P4 is a pointer to a SubProgram structure */ #define P4_ADVANCE (-19) /* P4 is a pointer to BtreeNext() or BtreePrev() */ /* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure ** is made. That copy is freed when the Vdbe is finalized. But if the ** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used. It still ** gets freed when the Vdbe is finalized so it still should be obtained ** from a single sqliteMalloc(). But no copy is made and the calling ** function should *not* try to free the KeyInfo. */ #define P4_KEYINFO_HANDOFF (-16) #define P4_KEYINFO_STATIC (-17) /* ** The Vdbe.aColName array contains 5n Mem structures, where n is the ** number of columns of data returned by the statement. */ #define COLNAME_NAME 0 #define COLNAME_DECLTYPE 1 #define COLNAME_DATABASE 2 #define COLNAME_TABLE 3 #define COLNAME_COLUMN 4 #ifdef SQLITE_ENABLE_COLUMN_METADATA # define COLNAME_N 5 /* Number of COLNAME_xxx symbols */ #else # ifdef SQLITE_OMIT_DECLTYPE # define COLNAME_N 1 /* Store only the name */ # else # define COLNAME_N 2 /* Store the name and decltype */ # endif #endif /* ** The following macro converts a relative address in the p2 field ** of a VdbeOp structure into a negative number so that ** sqlite3VdbeAddOpList() knows that the address is relative. Calling ** the macro again restores the address. */ #define ADDR(X) (-1-(X)) /* ** 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 mkopcodeh.awk script for details */ #define OP_Goto 1 #define OP_Gosub 2 #define OP_Return 3 #define OP_Yield 4 #define OP_HaltIfNull 5 #define OP_Halt 6 #define OP_Integer 7 #define OP_Int64 8 #define OP_Real 130 /* same as TK_FLOAT */ #define OP_String8 94 /* same as TK_STRING */ #define OP_String 9 #define OP_Null 10 #define OP_Blob 11 #define OP_Variable 12 #define OP_Move 13 #define OP_Copy 14 #define OP_SCopy 15 #define OP_ResultRow 16 #define OP_Concat 91 /* same as TK_CONCAT */ #define OP_Add 86 /* same as TK_PLUS */ #define OP_Subtract 87 /* same as TK_MINUS */ #define OP_Multiply 88 /* same as TK_STAR */ #define OP_Divide 89 /* same as TK_SLASH */ #define OP_Remainder 90 /* same as TK_REM */ #define OP_CollSeq 17 #define OP_Function 18 #define OP_BitAnd 82 /* same as TK_BITAND */ #define OP_BitOr 83 /* same as TK_BITOR */ #define OP_ShiftLeft 84 /* same as TK_LSHIFT */ #define OP_ShiftRight 85 /* same as TK_RSHIFT */ #define OP_AddImm 20 #define OP_MustBeInt 21 #define OP_RealAffinity 22 #define OP_ToText 141 /* same as TK_TO_TEXT */ #define OP_ToBlob 142 /* same as TK_TO_BLOB */ #define OP_ToNumeric 143 /* same as TK_TO_NUMERIC*/ #define OP_ToInt 144 /* same as TK_TO_INT */ #define OP_ToReal 145 /* same as TK_TO_REAL */ #define OP_Eq 76 /* same as TK_EQ */ #define OP_Ne 75 /* same as TK_NE */ #define OP_Lt 79 /* same as TK_LT */ #define OP_Le 78 /* same as TK_LE */ #define OP_Gt 77 /* same as TK_GT */ #define OP_Ge 80 /* same as TK_GE */ #define OP_Permutation 23 #define OP_Compare 24 #define OP_Jump 25 #define OP_And 69 /* same as TK_AND */ #define OP_Or 68 /* same as TK_OR */ #define OP_Not 19 /* same as TK_NOT */ #define OP_BitNot 93 /* same as TK_BITNOT */ #define OP_Once 26 #define OP_If 27 #define OP_IfNot 28 #define OP_IsNull 73 /* same as TK_ISNULL */ #define OP_NotNull 74 /* same as TK_NOTNULL */ #define OP_Column 29 #define OP_Affinity 30 #define OP_MakeRecord 31 #define OP_Count 32 #define OP_Savepoint 33 #define OP_AutoCommit 34 #define OP_Transaction 35 #define OP_ReadCookie 36 #define OP_SetCookie 37 #define OP_VerifyCookie 38 #define OP_OpenRead 39 #define OP_OpenWrite 40 #define OP_OpenAutoindex 41 #define OP_OpenEphemeral 42 #define OP_SorterOpen 43 #define OP_OpenPseudo 44 #define OP_Close 45 #define OP_SeekLt 46 #define OP_SeekLe 47 #define OP_SeekGe 48 #define OP_SeekGt 49 #define OP_Seek 50 #define OP_NotFound 51 #define OP_Found 52 #define OP_IsUnique 53 #define OP_NotExists 54 #define OP_Sequence 55 #define OP_NewRowid 56 #define OP_Insert 57 #define OP_InsertInt 58 #define OP_Delete 59 #define OP_ResetCount 60 #define OP_SorterCompare 61 #define OP_SorterData 62 #define OP_RowKey 63 #define OP_RowData 64 #define OP_Rowid 65 #define OP_NullRow 66 #define OP_Last 67 #define OP_SorterSort 70 #define OP_Sort 71 #define OP_Rewind 72 #define OP_SorterNext 81 #define OP_Prev 92 #define OP_Next 95 #define OP_SorterInsert 96 #define OP_IdxInsert 97 #define OP_IdxDelete 98 #define OP_IdxRowid 99 #define OP_IdxLT 100 #define OP_IdxGE 101 #define OP_Destroy 102 #define OP_Clear 103 #define OP_CreateIndex 104 #define OP_CreateTable 105 #define OP_ParseSchema 106 #define OP_LoadAnalysis 107 #define OP_DropTable 108 #define OP_DropIndex 109 #define OP_DropTrigger 110 #define OP_IntegrityCk 111 #define OP_RowSetAdd 112 #define OP_RowSetRead 113 #define OP_RowSetTest 114 #define OP_Program 115 #define OP_Param 116 #define OP_FkCounter 117 #define OP_FkIfZero 118 #define OP_MemMax 119 #define OP_IfPos 120 #define OP_IfNeg 121 #define OP_IfZero 122 #define OP_AggStep 123 #define OP_AggFinal 124 #define OP_Checkpoint 125 #define OP_JournalMode 126 #define OP_Vacuum 127 #define OP_IncrVacuum 128 #define OP_Expire 129 #define OP_TableLock 131 #define OP_VBegin 132 #define OP_VCreate 133 #define OP_VDestroy 134 #define OP_VOpen 135 #define OP_VFilter 136 #define OP_VColumn 137 #define OP_VNext 138 #define OP_VRename 139 #define OP_VUpdate 140 #define OP_Pagecount 146 #define OP_MaxPgcnt 147 #define OP_Trace 148 #define OP_Noop 149 #define OP_Explain 150 /* 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_OUT2_PRERELEASE 0x0002 /* out2-prerelease: */ #define OPFLG_IN1 0x0004 /* in1: P1 is an input */ #define OPFLG_IN2 0x0008 /* in2: P2 is an input */ #define OPFLG_IN3 0x0010 /* in3: P3 is an input */ #define OPFLG_OUT2 0x0020 /* out2: P2 is an output */ #define OPFLG_OUT3 0x0040 /* out3: P3 is an output */ #define OPFLG_INITIALIZER {\ /* 0 */ 0x00, 0x01, 0x01, 0x04, 0x04, 0x10, 0x00, 0x02,\ /* 8 */ 0x02, 0x02, 0x02, 0x02, 0x02, 0x00, 0x24, 0x24,\ /* 16 */ 0x00, 0x00, 0x00, 0x24, 0x04, 0x05, 0x04, 0x00,\ /* 24 */ 0x00, 0x01, 0x01, 0x05, 0x05, 0x00, 0x00, 0x00,\ /* 32 */ 0x02, 0x00, 0x00, 0x00, 0x02, 0x10, 0x00, 0x00,\ /* 40 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x11, 0x11,\ /* 48 */ 0x11, 0x11, 0x08, 0x11, 0x11, 0x11, 0x11, 0x02,\ /* 56 */ 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\ /* 64 */ 0x00, 0x02, 0x00, 0x01, 0x4c, 0x4c, 0x01, 0x01,\ /* 72 */ 0x01, 0x05, 0x05, 0x15, 0x15, 0x15, 0x15, 0x15,\ /* 80 */ 0x15, 0x01, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c,\ /* 88 */ 0x4c, 0x4c, 0x4c, 0x4c, 0x01, 0x24, 0x02, 0x01,\ /* 96 */ 0x08, 0x08, 0x00, 0x02, 0x01, 0x01, 0x02, 0x00,\ /* 104 */ 0x02, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\ /* 112 */ 0x0c, 0x45, 0x15, 0x01, 0x02, 0x00, 0x01, 0x08,\ /* 120 */ 0x05, 0x05, 0x05, 0x00, 0x00, 0x00, 0x02, 0x00,\ /* 128 */ 0x01, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,\ /* 136 */ 0x01, 0x00, 0x01, 0x00, 0x00, 0x04, 0x04, 0x04,\ /* 144 */ 0x04, 0x04, 0x02, 0x02, 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 Vdbe *sqlite3VdbeCreate(sqlite3*); SQLITE_PRIVATE int sqlite3VdbeAddOp0(Vdbe*,int); SQLITE_PRIVATE int sqlite3VdbeAddOp1(Vdbe*,int,int); SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe*,int,int,int); 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 sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int); SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp); SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*); 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 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N); SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe*, int); SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe*, int); SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe*); SQLITE_PRIVATE void sqlite3VdbeRunOnlyOnce(Vdbe*); SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe*); SQLITE_PRIVATE void sqlite3VdbeDeleteObject(sqlite3*,Vdbe*); SQLITE_PRIVATE void sqlite3VdbeMakeReady(Vdbe*,Parse*); SQLITE_PRIVATE int sqlite3VdbeFinalize(Vdbe*); SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe*, int); SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe*); #ifdef SQLITE_DEBUG SQLITE_PRIVATE int sqlite3VdbeAssertMayAbort(Vdbe *, int); SQLITE_PRIVATE void sqlite3VdbeTrace(Vdbe*,FILE*); #endif SQLITE_PRIVATE void sqlite3VdbeResetStepResult(Vdbe*); SQLITE_PRIVATE void sqlite3VdbeRewind(Vdbe*); SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe*); SQLITE_PRIVATE void sqlite3VdbeSetNumCols(Vdbe*,int); SQLITE_PRIVATE int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*)); SQLITE_PRIVATE void sqlite3VdbeCountChanges(Vdbe*); SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe*); SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, int); SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe*,Vdbe*); SQLITE_PRIVATE VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*); SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetValue(Vdbe*, int, u8); SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe*, int); #ifndef SQLITE_OMIT_TRACE SQLITE_PRIVATE char *sqlite3VdbeExpandSql(Vdbe*, const char*); #endif SQLITE_PRIVATE void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*); SQLITE_PRIVATE int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*); SQLITE_PRIVATE UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo *, char *, int, char **); #ifndef SQLITE_OMIT_TRIGGER SQLITE_PRIVATE void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *); #endif #ifndef NDEBUG SQLITE_PRIVATE void sqlite3VdbeComment(Vdbe*, const char*, ...); # define VdbeComment(X) sqlite3VdbeComment X SQLITE_PRIVATE void sqlite3VdbeNoopComment(Vdbe*, const char*, ...); # define VdbeNoopComment(X) sqlite3VdbeNoopComment X #else # define VdbeComment(X) # define VdbeNoopComment(X) #endif #endif /************** End of vdbe.h ************************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ /************** Include pager.h in the middle of sqliteInt.h *****************/ /************** Begin file pager.h *******************************************/ /* ** 2001 September 15 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This header file defines the interface that the sqlite page cache ** subsystem. The page cache subsystem reads and writes a file a page ** at a time and provides a journal for rollback. */ #ifndef _PAGER_H_ #define _PAGER_H_ /* ** Default maximum size for persistent journal files. A negative ** value means no limit. This value may be overridden using the ** sqlite3PagerJournalSizeLimit() API. See also "PRAGMA journal_size_limit". */ #ifndef SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT #define SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT -1 #endif /* ** The type used to represent a page number. The first page in a file ** is called page 1. 0 is used to represent "not a page". */ typedef u32 Pgno; /* ** Each open file is managed by a separate instance of the "Pager" structure. */ typedef struct Pager Pager; /* ** Handle type for pages. */ typedef struct PgHdr DbPage; /* ** Page number PAGER_MJ_PGNO is never used in an SQLite database (it is ** reserved for working around a windows/posix incompatibility). It is ** used in the journal to signify that the remainder of the journal file ** is devoted to storing a master journal name - there are no more pages to ** roll back. See comments for function writeMasterJournal() in pager.c ** for details. */ #define PAGER_MJ_PGNO(x) ((Pgno)((PENDING_BYTE/((x)->pageSize))+1)) /* ** Allowed values for the flags parameter to sqlite3PagerOpen(). ** ** NOTE: These values must match the corresponding BTREE_ values in btree.h. */ #define PAGER_OMIT_JOURNAL 0x0001 /* Do not use a rollback journal */ #define PAGER_MEMORY 0x0002 /* In-memory database */ /* ** Valid values for the second argument to sqlite3PagerLockingMode(). */ #define PAGER_LOCKINGMODE_QUERY -1 #define PAGER_LOCKINGMODE_NORMAL 0 #define PAGER_LOCKINGMODE_EXCLUSIVE 1 /* ** Numeric constants that encode the journalmode. */ #define PAGER_JOURNALMODE_QUERY (-1) /* Query the value of journalmode */ #define PAGER_JOURNALMODE_DELETE 0 /* Commit by deleting journal file */ #define PAGER_JOURNALMODE_PERSIST 1 /* Commit by zeroing journal header */ #define PAGER_JOURNALMODE_OFF 2 /* Journal omitted. */ #define PAGER_JOURNALMODE_TRUNCATE 3 /* Commit by truncating journal */ #define PAGER_JOURNALMODE_MEMORY 4 /* In-memory journal file */ #define PAGER_JOURNALMODE_WAL 5 /* Use write-ahead logging */ /* ** 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. */ /* Open and close a Pager connection. */ SQLITE_PRIVATE int sqlite3PagerOpen( sqlite3_vfs*, Pager **ppPager, const char*, int, int, int, void(*)(DbPage*) ); SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager); SQLITE_PRIVATE int sqlite3PagerReadFileheader(Pager*, int, unsigned char*); /* Functions used to configure a Pager object. */ SQLITE_PRIVATE void sqlite3PagerSetBusyhandler(Pager*, int(*)(void *), void *); SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager*, u32*, int); SQLITE_PRIVATE int sqlite3PagerMaxPageCount(Pager*, int); SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager*, int); SQLITE_PRIVATE void sqlite3PagerShrink(Pager*); SQLITE_PRIVATE void sqlite3PagerSetSafetyLevel(Pager*,int,int,int); SQLITE_PRIVATE int sqlite3PagerLockingMode(Pager *, int); SQLITE_PRIVATE int sqlite3PagerSetJournalMode(Pager *, int); SQLITE_PRIVATE int sqlite3PagerGetJournalMode(Pager*); SQLITE_PRIVATE int sqlite3PagerOkToChangeJournalMode(Pager*); SQLITE_PRIVATE i64 sqlite3PagerJournalSizeLimit(Pager *, i64); SQLITE_PRIVATE sqlite3_backup **sqlite3PagerBackupPtr(Pager*); /* Functions used to obtain and release page references. */ SQLITE_PRIVATE int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag); #define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0) SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno); SQLITE_PRIVATE void sqlite3PagerRef(DbPage*); SQLITE_PRIVATE void sqlite3PagerUnref(DbPage*); /* Operations on page references. */ SQLITE_PRIVATE int sqlite3PagerWrite(DbPage*); SQLITE_PRIVATE void sqlite3PagerDontWrite(DbPage*); SQLITE_PRIVATE int sqlite3PagerMovepage(Pager*,DbPage*,Pgno,int); SQLITE_PRIVATE int sqlite3PagerPageRefcount(DbPage*); SQLITE_PRIVATE void *sqlite3PagerGetData(DbPage *); SQLITE_PRIVATE void *sqlite3PagerGetExtra(DbPage *); /* Functions used to manage pager transactions and savepoints. */ SQLITE_PRIVATE void sqlite3PagerPagecount(Pager*, int*); SQLITE_PRIVATE int sqlite3PagerBegin(Pager*, int exFlag, int); SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, int); SQLITE_PRIVATE int sqlite3PagerExclusiveLock(Pager*); SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager); SQLITE_PRIVATE int sqlite3PagerCommitPhaseTwo(Pager*); SQLITE_PRIVATE int sqlite3PagerRollback(Pager*); SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int n); SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint); SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager); SQLITE_PRIVATE int sqlite3PagerCheckpoint(Pager *pPager, int, int*, int*); SQLITE_PRIVATE int sqlite3PagerWalSupported(Pager *pPager); SQLITE_PRIVATE int sqlite3PagerWalCallback(Pager *pPager); SQLITE_PRIVATE int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen); SQLITE_PRIVATE int sqlite3PagerCloseWal(Pager *pPager); #ifdef SQLITE_ENABLE_ZIPVFS SQLITE_PRIVATE int sqlite3PagerWalFramesize(Pager *pPager); #endif /* Functions used to query pager state and configuration. */ SQLITE_PRIVATE u8 sqlite3PagerIsreadonly(Pager*); SQLITE_PRIVATE int sqlite3PagerRefcount(Pager*); SQLITE_PRIVATE int sqlite3PagerMemUsed(Pager*); SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager*); SQLITE_PRIVATE const sqlite3_vfs *sqlite3PagerVfs(Pager*); SQLITE_PRIVATE sqlite3_file *sqlite3PagerFile(Pager*); SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager*); SQLITE_PRIVATE int sqlite3PagerNosync(Pager*); SQLITE_PRIVATE void *sqlite3PagerTempSpace(Pager*); SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager*); SQLITE_PRIVATE void sqlite3PagerCacheStat(Pager *, int, int, int *); SQLITE_PRIVATE void sqlite3PagerClearCache(Pager *); /* Functions used to truncate the database file. */ SQLITE_PRIVATE void sqlite3PagerTruncateImage(Pager*,Pgno); #if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_WAL) SQLITE_PRIVATE void *sqlite3PagerCodec(DbPage *); #endif /* Functions to support testing and debugging. */ #if !defined(NDEBUG) || defined(SQLITE_TEST) SQLITE_PRIVATE Pgno sqlite3PagerPagenumber(DbPage*); SQLITE_PRIVATE int sqlite3PagerIswriteable(DbPage*); #endif #ifdef SQLITE_TEST SQLITE_PRIVATE int *sqlite3PagerStats(Pager*); SQLITE_PRIVATE void sqlite3PagerRefdump(Pager*); void disable_simulated_io_errors(void); void enable_simulated_io_errors(void); #else # define disable_simulated_io_errors() # define enable_simulated_io_errors() #endif #endif /* _PAGER_H_ */ /************** End of pager.h ***********************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ /************** Include pcache.h in the middle of sqliteInt.h ****************/ /************** Begin file pcache.h ******************************************/ /* ** 2008 August 05 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This header file defines the interface that the sqlite page cache ** subsystem. */ #ifndef _PCACHE_H_ typedef struct PgHdr PgHdr; typedef struct PCache PCache; /* ** Every page in the cache is controlled by an instance of the following ** structure. */ struct PgHdr { sqlite3_pcache_page *pPage; /* Pcache object page handle */ void *pData; /* Page data */ void *pExtra; /* Extra content */ PgHdr *pDirty; /* Transient list of dirty pages */ Pager *pPager; /* The pager this page is part of */ Pgno pgno; /* Page number for this page */ #ifdef SQLITE_CHECK_PAGES u32 pageHash; /* Hash of page content */ #endif u16 flags; /* PGHDR flags defined below */ /********************************************************************** ** Elements above are public. All that follows is private to pcache.c ** and should not be accessed by other modules. */ i16 nRef; /* Number of users of this page */ PCache *pCache; /* Cache that owns this page */ PgHdr *pDirtyNext; /* Next element in list of dirty pages */ PgHdr *pDirtyPrev; /* Previous element in list of dirty pages */ }; /* Bit values for PgHdr.flags */ #define PGHDR_DIRTY 0x002 /* Page has changed */ #define PGHDR_NEED_SYNC 0x004 /* Fsync the rollback journal before ** writing this page to the database */ #define PGHDR_NEED_READ 0x008 /* Content is unread */ #define PGHDR_REUSE_UNLIKELY 0x010 /* A hint that reuse is unlikely */ #define PGHDR_DONT_WRITE 0x020 /* Do not write content to disk */ /* 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. */ SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *, int sz, int n); /* Create a new pager cache. ** Under memory stress, invoke xStress to try to make pages clean. ** Only clean and unpinned pages can be reclaimed. */ SQLITE_PRIVATE void sqlite3PcacheOpen( int szPage, /* Size of every page */ int szExtra, /* Extra space associated with each page */ int bPurgeable, /* True if pages are on backing store */ int (*xStress)(void*, PgHdr*), /* Call to try to make pages clean */ void *pStress, /* Argument to xStress */ PCache *pToInit /* Preallocated space for the PCache */ ); /* Modify the page-size after the cache has been created. */ SQLITE_PRIVATE void sqlite3PcacheSetPageSize(PCache *, int); /* Return the size in bytes of a PCache object. Used to preallocate ** storage space. */ SQLITE_PRIVATE int sqlite3PcacheSize(void); /* One release per successful fetch. Page is pinned until released. ** Reference counted. */ SQLITE_PRIVATE int sqlite3PcacheFetch(PCache*, Pgno, int createFlag, PgHdr**); SQLITE_PRIVATE void sqlite3PcacheRelease(PgHdr*); SQLITE_PRIVATE void sqlite3PcacheDrop(PgHdr*); /* Remove page from cache */ SQLITE_PRIVATE void sqlite3PcacheMakeDirty(PgHdr*); /* Make sure page is marked dirty */ SQLITE_PRIVATE void sqlite3PcacheMakeClean(PgHdr*); /* Mark a single page as clean */ SQLITE_PRIVATE void sqlite3PcacheCleanAll(PCache*); /* Mark all dirty list pages as clean */ /* Change a page number. Used by incr-vacuum. */ SQLITE_PRIVATE void sqlite3PcacheMove(PgHdr*, Pgno); /* Remove all pages with pgno>x. Reset the cache if x==0 */ SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache*, Pgno x); /* Get a list of all dirty pages in the cache, sorted by page number */ SQLITE_PRIVATE PgHdr *sqlite3PcacheDirtyList(PCache*); /* Reset and close the cache object */ SQLITE_PRIVATE void sqlite3PcacheClose(PCache*); /* Clear flags from pages of the page cache */ SQLITE_PRIVATE void sqlite3PcacheClearSyncFlags(PCache *); /* Discard the contents of the cache */ SQLITE_PRIVATE void sqlite3PcacheClear(PCache*); /* Return the total number of outstanding page references */ SQLITE_PRIVATE int sqlite3PcacheRefCount(PCache*); /* Increment the reference count of an existing page */ SQLITE_PRIVATE void sqlite3PcacheRef(PgHdr*); SQLITE_PRIVATE int sqlite3PcachePageRefcount(PgHdr*); /* Return the total number of pages stored in the cache */ SQLITE_PRIVATE int sqlite3PcachePagecount(PCache*); #if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG) /* Iterate through all dirty pages currently stored in the cache. This ** interface is only available if SQLITE_CHECK_PAGES is defined when the ** library is built. */ SQLITE_PRIVATE void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHdr *)); #endif /* Set and get the suggested cache-size for the specified pager-cache. ** ** If no global maximum is configured, then the system attempts to limit ** the total number of pages cached by purgeable pager-caches to the sum ** of the suggested cache-sizes. */ SQLITE_PRIVATE void sqlite3PcacheSetCachesize(PCache *, int); #ifdef SQLITE_TEST SQLITE_PRIVATE int sqlite3PcacheGetCachesize(PCache *); #endif /* Free up as much memory as possible from the page cache */ SQLITE_PRIVATE void sqlite3PcacheShrink(PCache*); #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT /* Try to return memory used by the pcache module to the main memory heap */ SQLITE_PRIVATE int sqlite3PcacheReleaseMemory(int); #endif #ifdef SQLITE_TEST SQLITE_PRIVATE void sqlite3PcacheStats(int*,int*,int*,int*); #endif SQLITE_PRIVATE void sqlite3PCacheSetDefault(void); #endif /* _PCACHE_H_ */ /************** End of pcache.h **********************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ /************** Include os.h in the middle of sqliteInt.h ********************/ /************** Begin file os.h **********************************************/ /* ** 2001 September 16 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ****************************************************************************** ** ** This header file (together with is companion C source-code file ** "os.c") attempt to abstract the underlying operating system so that ** the SQLite library will work on both POSIX and windows systems. ** ** This header file is #include-ed by sqliteInt.h and thus ends up ** being included by every source file. */ #ifndef _SQLITE_OS_H_ #define _SQLITE_OS_H_ /* ** Figure out if we are dealing with Unix, Windows, or some other ** operating system. After the following block of preprocess macros, ** all of SQLITE_OS_UNIX, SQLITE_OS_WIN, SQLITE_OS_OS2, and SQLITE_OS_OTHER ** will defined to either 1 or 0. One of the four will be 1. The other ** three will be 0. */ #if defined(SQLITE_OS_OTHER) # if SQLITE_OS_OTHER==1 # undef SQLITE_OS_UNIX # define SQLITE_OS_UNIX 0 # undef SQLITE_OS_WIN # define SQLITE_OS_WIN 0 # undef SQLITE_OS_OS2 # define SQLITE_OS_OS2 0 # else # undef SQLITE_OS_OTHER # endif #endif #if !defined(SQLITE_OS_UNIX) && !defined(SQLITE_OS_OTHER) # define SQLITE_OS_OTHER 0 # ifndef SQLITE_OS_WIN # if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || defined(__MINGW32__) || defined(__BORLANDC__) # define SQLITE_OS_WIN 1 # define SQLITE_OS_UNIX 0 # define SQLITE_OS_OS2 0 # elif defined(__EMX__) || defined(_OS2) || defined(OS2) || defined(_OS2_) || defined(__OS2__) # define SQLITE_OS_WIN 0 # define SQLITE_OS_UNIX 0 # define SQLITE_OS_OS2 1 # else # define SQLITE_OS_WIN 0 # define SQLITE_OS_UNIX 1 # define SQLITE_OS_OS2 0 # endif # else # define SQLITE_OS_UNIX 0 # define SQLITE_OS_OS2 0 # endif #else # ifndef SQLITE_OS_WIN # define SQLITE_OS_WIN 0 # endif #endif /* ** Define the maximum size of a temporary filename */ #if SQLITE_OS_WIN # include # define SQLITE_TEMPNAME_SIZE (MAX_PATH+50) #elif SQLITE_OS_OS2 # if (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ >= 3) && defined(OS2_HIGH_MEMORY) # include /* has to be included before os2.h for linking to work */ # endif # define INCL_DOSDATETIME # define INCL_DOSFILEMGR # define INCL_DOSERRORS # define INCL_DOSMISC # define INCL_DOSPROCESS # define INCL_DOSMODULEMGR # define INCL_DOSSEMAPHORES # include # include # define SQLITE_TEMPNAME_SIZE (CCHMAXPATHCOMP) #else # define SQLITE_TEMPNAME_SIZE 200 #endif /* ** Determine if we are dealing with Windows NT. ** ** We ought to be able to determine if we are compiling for win98 or winNT ** using the _WIN32_WINNT macro as follows: ** ** #if defined(_WIN32_WINNT) ** # define SQLITE_OS_WINNT 1 ** #else ** # define SQLITE_OS_WINNT 0 ** #endif ** ** However, vs2005 does not set _WIN32_WINNT by default, as it ought to, ** so the above test does not work. We'll just assume that everything is ** winNT unless the programmer explicitly says otherwise by setting ** SQLITE_OS_WINNT to 0. */ #if SQLITE_OS_WIN && !defined(SQLITE_OS_WINNT) # define SQLITE_OS_WINNT 1 #endif /* ** Determine if we are dealing with WindowsCE - which has a much ** reduced API. */ #if defined(_WIN32_WCE) # define SQLITE_OS_WINCE 1 #else # define SQLITE_OS_WINCE 0 #endif /* If the SET_FULLSYNC macro is not defined above, then make it ** a no-op */ #ifndef SET_FULLSYNC # define SET_FULLSYNC(x,y) #endif /* ** The default size of a disk sector */ #ifndef SQLITE_DEFAULT_SECTOR_SIZE # define SQLITE_DEFAULT_SECTOR_SIZE 4096 #endif /* ** Temporary files are named starting with this prefix followed by 16 random ** alphanumeric characters, and no file extension. They are stored in the ** OS's standard temporary file directory, and are deleted prior to exit. ** If sqlite is being embedded in another program, you may wish to change the ** prefix to reflect your program's name, so that if your program exits ** prematurely, old temporary files can be easily identified. This can be done ** using -DSQLITE_TEMP_FILE_PREFIX=myprefix_ on the compiler command line. ** ** 2006-10-31: The default prefix used to be "sqlite_". But then ** Mcafee started using SQLite in their anti-virus product and it ** started putting files with the "sqlite" name in the c:/temp folder. ** This annoyed many windows users. Those users would then do a ** Google search for "sqlite", find the telephone numbers of the ** developers and call to wake them up at night and complain. ** For this reason, the default name prefix is changed to be "sqlite" ** spelled backwards. So the temp files are still identified, but ** anybody smart enough to figure out the code is also likely smart ** enough to know that calling the developer will not help get rid ** of the file. */ #ifndef SQLITE_TEMP_FILE_PREFIX # define SQLITE_TEMP_FILE_PREFIX "etilqs_" #endif /* ** The following values may be passed as the second argument to ** sqlite3OsLock(). The various locks exhibit the following semantics: ** ** SHARED: Any number of processes may hold a SHARED lock simultaneously. ** RESERVED: A single process may hold a RESERVED lock on a file at ** any time. Other processes may hold and obtain new SHARED locks. ** PENDING: A single process may hold a PENDING lock on a file at ** any one time. Existing SHARED locks may persist, but no new ** SHARED locks may be obtained by other processes. ** EXCLUSIVE: An EXCLUSIVE lock precludes all other locks. ** ** PENDING_LOCK may not be passed directly to sqlite3OsLock(). Instead, a ** process that requests an EXCLUSIVE lock may actually obtain a PENDING ** lock. This can be upgraded to an EXCLUSIVE lock by a subsequent call to ** sqlite3OsLock(). */ #define NO_LOCK 0 #define SHARED_LOCK 1 #define RESERVED_LOCK 2 #define PENDING_LOCK 3 #define EXCLUSIVE_LOCK 4 /* ** File Locking Notes: (Mostly about windows but also some info for Unix) ** ** We cannot use LockFileEx() or UnlockFileEx() on Win95/98/ME because ** those functions are not available. So we use only LockFile() and ** UnlockFile(). ** ** LockFile() prevents not just writing but also reading by other processes. ** A SHARED_LOCK is obtained by locking a single randomly-chosen ** byte out of a specific range of bytes. The lock byte is obtained at ** random so two separate readers can probably access the file at the ** same time, unless they are unlucky and choose the same lock byte. ** An EXCLUSIVE_LOCK is obtained by locking all bytes in the range. ** There can only be one writer. A RESERVED_LOCK is obtained by locking ** a single byte of the file that is designated as the reserved lock byte. ** A PENDING_LOCK is obtained by locking a designated byte different from ** the RESERVED_LOCK byte. ** ** On WinNT/2K/XP systems, LockFileEx() and UnlockFileEx() are available, ** which means we can use reader/writer locks. When reader/writer locks ** are used, the lock is placed on the same range of bytes that is used ** for probabilistic locking in Win95/98/ME. Hence, the locking scheme ** will support two or more Win95 readers or two or more WinNT readers. ** But a single Win95 reader will lock out all WinNT readers and a single ** WinNT reader will lock out all other Win95 readers. ** ** The following #defines specify the range of bytes used for locking. ** SHARED_SIZE is the number of bytes available in the pool from which ** a random byte is selected for a shared lock. The pool of bytes for ** shared locks begins at SHARED_FIRST. ** ** The same locking strategy and ** byte ranges are used for Unix. This leaves open the possiblity of having ** clients on win95, winNT, and unix all talking to the same shared file ** and all locking correctly. To do so would require that samba (or whatever ** tool is being used for file sharing) implements locks correctly between ** windows and unix. I'm guessing that isn't likely to happen, but by ** using the same locking range we are at least open to the possibility. ** ** Locking in windows is manditory. For this reason, we cannot store ** actual data in the bytes used for locking. The pager never allocates ** the pages involved in locking therefore. SHARED_SIZE is selected so ** that all locks will fit on a single page even at the minimum page size. ** PENDING_BYTE defines the beginning of the locks. By default PENDING_BYTE ** is set high so that we don't have to allocate an unused page except ** for very large databases. But one should test the page skipping logic ** by setting PENDING_BYTE low and running the entire regression suite. ** ** Changing the value of PENDING_BYTE results in a subtly incompatible ** file format. Depending on how it is changed, you might not notice ** the incompatibility right away, even running a full regression test. ** The default location of PENDING_BYTE is the first byte past the ** 1GB boundary. ** */ #ifdef SQLITE_OMIT_WSD # define PENDING_BYTE (0x40000000) #else # define PENDING_BYTE sqlite3PendingByte #endif #define RESERVED_BYTE (PENDING_BYTE+1) #define SHARED_FIRST (PENDING_BYTE+2) #define SHARED_SIZE 510 /* ** Wrapper around OS specific sqlite3_os_init() function. */ SQLITE_PRIVATE int sqlite3OsInit(void); /* ** Functions for accessing sqlite3_file methods */ SQLITE_PRIVATE int sqlite3OsClose(sqlite3_file*); SQLITE_PRIVATE int sqlite3OsRead(sqlite3_file*, void*, int amt, i64 offset); SQLITE_PRIVATE int sqlite3OsWrite(sqlite3_file*, const void*, int amt, i64 offset); SQLITE_PRIVATE int sqlite3OsTruncate(sqlite3_file*, i64 size); SQLITE_PRIVATE int sqlite3OsSync(sqlite3_file*, int); SQLITE_PRIVATE int sqlite3OsFileSize(sqlite3_file*, i64 *pSize); SQLITE_PRIVATE int sqlite3OsLock(sqlite3_file*, int); SQLITE_PRIVATE int sqlite3OsUnlock(sqlite3_file*, int); SQLITE_PRIVATE int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut); SQLITE_PRIVATE int sqlite3OsFileControl(sqlite3_file*,int,void*); SQLITE_PRIVATE void sqlite3OsFileControlHint(sqlite3_file*,int,void*); #define SQLITE_FCNTL_DB_UNCHANGED 0xca093fa0 SQLITE_PRIVATE int sqlite3OsSectorSize(sqlite3_file *id); SQLITE_PRIVATE int sqlite3OsDeviceCharacteristics(sqlite3_file *id); SQLITE_PRIVATE int sqlite3OsShmMap(sqlite3_file *,int,int,int,void volatile **); SQLITE_PRIVATE int sqlite3OsShmLock(sqlite3_file *id, int, int, int); SQLITE_PRIVATE void sqlite3OsShmBarrier(sqlite3_file *id); SQLITE_PRIVATE int sqlite3OsShmUnmap(sqlite3_file *id, int); /* ** Functions for accessing sqlite3_vfs methods */ SQLITE_PRIVATE int sqlite3OsOpen(sqlite3_vfs *, const char *, sqlite3_file*, int, int *); SQLITE_PRIVATE int sqlite3OsDelete(sqlite3_vfs *, const char *, int); SQLITE_PRIVATE int sqlite3OsAccess(sqlite3_vfs *, const char *, int, int *pResOut); SQLITE_PRIVATE int sqlite3OsFullPathname(sqlite3_vfs *, const char *, int, char *); #ifndef SQLITE_OMIT_LOAD_EXTENSION SQLITE_PRIVATE void *sqlite3OsDlOpen(sqlite3_vfs *, const char *); SQLITE_PRIVATE void sqlite3OsDlError(sqlite3_vfs *, int, char *); SQLITE_PRIVATE void (*sqlite3OsDlSym(sqlite3_vfs *, void *, const char *))(void); SQLITE_PRIVATE void sqlite3OsDlClose(sqlite3_vfs *, void *); #endif /* SQLITE_OMIT_LOAD_EXTENSION */ SQLITE_PRIVATE int sqlite3OsRandomness(sqlite3_vfs *, int, char *); SQLITE_PRIVATE int sqlite3OsSleep(sqlite3_vfs *, int); SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *, sqlite3_int64*); /* ** Convenience functions for opening and closing files using ** sqlite3_malloc() to obtain space for the file-handle structure. */ SQLITE_PRIVATE int sqlite3OsOpenMalloc(sqlite3_vfs *, const char *, sqlite3_file **, int,int*); SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *); #endif /* _SQLITE_OS_H_ */ /************** End of os.h **************************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ /************** Include mutex.h in the middle of sqliteInt.h *****************/ /************** Begin file mutex.h *******************************************/ /* ** 2007 August 28 ** ** 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. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** ** This file contains the common header for all mutex implementations. ** The sqliteInt.h header #includes this file so that it is available ** to all source files. We break it out in an effort to keep the code ** better organized. ** ** NOTE: source files should *not* #include this header file directly. ** Source files should #include the sqliteInt.h file and let that file ** include this one indirectly. */ /* ** Figure out what version of the code to use. The choices are ** ** SQLITE_MUTEX_OMIT No mutex logic. Not even stubs. The ** mutexes implemention cannot be overridden ** at start-time. ** ** SQLITE_MUTEX_NOOP For single-threaded applications. No ** mutual exclusion is provided. But this ** implementation can be overridden at ** start-time. ** ** SQLITE_MUTEX_PTHREADS For multi-threaded applications on Unix. ** ** SQLITE_MUTEX_W32 For multi-threaded applications on Win32. ** ** SQLITE_MUTEX_OS2 For multi-threaded applications on OS/2. */ #if !SQLITE_THREADSAFE # define SQLITE_MUTEX_OMIT #endif #if SQLITE_THREADSAFE && !defined(SQLITE_MUTEX_NOOP) # if SQLITE_OS_UNIX # define SQLITE_MUTEX_PTHREADS # elif SQLITE_OS_WIN # define SQLITE_MUTEX_W32 # elif SQLITE_OS_OS2 # define SQLITE_MUTEX_OS2 # else # define SQLITE_MUTEX_NOOP # endif #endif #ifdef SQLITE_MUTEX_OMIT /* ** If this is a no-op implementation, implement everything as macros. */ #define sqlite3_mutex_alloc(X) ((sqlite3_mutex*)8) #define sqlite3_mutex_free(X) #define sqlite3_mutex_enter(X) #define sqlite3_mutex_try(X) SQLITE_OK #define sqlite3_mutex_leave(X) #define sqlite3_mutex_held(X) ((void)(X),1) #define sqlite3_mutex_notheld(X) ((void)(X),1) #define sqlite3MutexAlloc(X) ((sqlite3_mutex*)8) #define sqlite3MutexInit() SQLITE_OK #define sqlite3MutexEnd() #define MUTEX_LOGIC(X) #else #define MUTEX_LOGIC(X) X #endif /* defined(SQLITE_MUTEX_OMIT) */ /************** End of mutex.h ***********************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ /* ** Each database file to be accessed by the system is an instance ** of the following structure. There are normally two of these structures ** in the sqlite.aDb[] array. aDb[0] is the main database file and ** aDb[1] is the database file used to hold temporary tables. Additional ** databases may be attached. */ struct Db { char *zName; /* Name of this database */ Btree *pBt; /* The B*Tree structure for this database file */ u8 inTrans; /* 0: not writable. 1: Transaction. 2: Checkpoint */ u8 safety_level; /* How aggressive at syncing data to disk */ Schema *pSchema; /* Pointer to database schema (possibly shared) */ }; /* ** An instance of the following structure stores a database schema. ** ** Most Schema objects are associated with a Btree. The exception is ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing. ** In shared cache mode, a single Schema object can be shared by multiple ** Btrees that refer to the same underlying BtShared object. ** ** Schema objects are automatically deallocated when the last Btree that ** references them is destroyed. The TEMP Schema is manually freed by ** sqlite3_close(). * ** A thread must be holding a mutex on the corresponding Btree in order ** to access Schema content. This implies that the thread must also be ** holding a mutex on the sqlite3 connection pointer that owns the Btree. ** For a TEMP Schema, only the connection mutex is required. */ struct Schema { int schema_cookie; /* Database schema version number for this file */ int iGeneration; /* Generation counter. Incremented with each change */ Hash tblHash; /* All tables indexed by name */ Hash idxHash; /* All (named) indices indexed by name */ Hash trigHash; /* All triggers indexed by name */ Hash fkeyHash; /* All foreign keys by referenced table name */ Table *pSeqTab; /* The sqlite_sequence table used by AUTOINCREMENT */ u8 file_format; /* Schema format version for this file */ u8 enc; /* Text encoding used by this database */ u16 flags; /* Flags associated with this schema */ int cache_size; /* Number of pages to use in the cache */ }; /* ** These macros can be used to test, set, or clear bits in the ** Db.pSchema->flags field. */ #define DbHasProperty(D,I,P) (((D)->aDb[I].pSchema->flags&(P))==(P)) #define DbHasAnyProperty(D,I,P) (((D)->aDb[I].pSchema->flags&(P))!=0) #define DbSetProperty(D,I,P) (D)->aDb[I].pSchema->flags|=(P) #define DbClearProperty(D,I,P) (D)->aDb[I].pSchema->flags&=~(P) /* ** Allowed values for the DB.pSchema->flags field. ** ** The DB_SchemaLoaded flag is set after the database schema has been ** read into internal hash tables. ** ** DB_UnresetViews means that one or more views have column names that ** have been filled out. If the schema changes, these column names might ** changes and so the view will need to be reset. */ #define DB_SchemaLoaded 0x0001 /* The schema has been loaded */ #define DB_UnresetViews 0x0002 /* Some views have defined column names */ #define DB_Empty 0x0004 /* The file is empty (length 0 bytes) */ /* ** The number of different kinds of things that can be limited ** using the sqlite3_limit() interface. */ #define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1) /* ** Lookaside malloc is a set of fixed-size buffers that can be used ** to satisfy small transient memory allocation requests for objects ** associated with a particular database connection. The use of ** lookaside malloc provides a significant performance enhancement ** (approx 10%) by avoiding numerous malloc/free requests while parsing ** SQL statements. ** ** The Lookaside structure holds configuration information about the ** lookaside malloc subsystem. Each available memory allocation in ** the lookaside subsystem is stored on a linked list of LookasideSlot ** objects. ** ** Lookaside allocations are only allowed for objects that are associated ** 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 */ }; struct LookasideSlot { LookasideSlot *pNext; /* Next buffer in the list of free buffers */ }; /* ** A hash table for function definitions. ** ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots. ** Collisions are on the FuncDef.pHash chain. */ struct FuncDefHash { FuncDef *a[23]; /* Hash table for functions */ }; /* ** Each database connection is an instance of the following structure. */ struct sqlite3 { sqlite3_vfs *pVfs; /* OS Interface */ struct Vdbe *pVdbe; /* List of active virtual machines */ CollSeq *pDfltColl; /* The default collating sequence (BINARY) */ sqlite3_mutex *mutex; /* Connection mutex */ Db *aDb; /* All backends */ int nDb; /* Number of backends currently in use */ int flags; /* Miscellaneous flags. See below */ i64 lastRowid; /* ROWID of most recent insert (see above) */ unsigned int openFlags; /* Flags passed to sqlite3_vfs.xOpen() */ int errCode; /* Most recent error code (SQLITE_*) */ int errMask; /* & result codes with this before returning */ 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 */ int nChange; /* Value returned by sqlite3_changes() */ int nTotalChange; /* Value returned by sqlite3_total_changes() */ int aLimit[SQLITE_N_LIMIT]; /* Limits */ struct sqlite3InitInfo { /* Information used during initialization */ int newTnum; /* Rootpage of table being initialized */ u8 iDb; /* Which db file is being initialized */ u8 busy; /* TRUE if currently initializing */ u8 orphanTrigger; /* Last statement is orphaned TEMP trigger */ } init; int activeVdbeCnt; /* Number of VDBEs currently executing */ int writeVdbeCnt; /* Number of active VDBEs that are writing */ int vdbeExecCnt; /* Number of nested calls to VdbeExec() */ int nExtension; /* Number of loaded extensions */ void **aExtension; /* Array of shared library handles */ void (*xTrace)(void*,const char*); /* Trace function */ void *pTraceArg; /* Argument to the trace function */ void (*xProfile)(void*,const char*,u64); /* Profiling function */ void *pProfileArg; /* Argument to profile function */ void *pCommitArg; /* Argument to xCommitCallback() */ int (*xCommitCallback)(void*); /* Invoked at every commit. */ void *pRollbackArg; /* Argument to xRollbackCallback() */ void (*xRollbackCallback)(void*); /* Invoked at every commit. */ void *pUpdateArg; void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64); #ifndef SQLITE_OMIT_WAL int (*xWalCallback)(void *, sqlite3 *, const char *, int); void *pWalArg; #endif void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*); void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*); void *pCollNeededArg; sqlite3_value *pErr; /* Most recent error message */ char *zErrMsg; /* Most recent error message (UTF-8 encoded) */ char *zErrMsg16; /* Most recent error message (UTF-16 encoded) */ union { volatile int isInterrupted; /* True if sqlite3_interrupt has been called */ double notUsed1; /* Spacer */ } u1; Lookaside lookaside; /* Lookaside malloc configuration */ #ifndef SQLITE_OMIT_AUTHORIZATION int (*xAuth)(void*,int,const char*,const char*,const char*,const char*); /* Access authorization function */ void *pAuthArg; /* 1st argument to the access auth function */ #endif #ifndef SQLITE_OMIT_PROGRESS_CALLBACK int (*xProgress)(void *); /* The progress callback */ void *pProgressArg; /* Argument to the progress callback */ int nProgressOps; /* Number of opcodes for progress callback */ #endif #ifndef SQLITE_OMIT_VIRTUALTABLE int nVTrans; /* Allocated size of aVTrans */ Hash aModule; /* populated by sqlite3_create_module() */ VtabCtx *pVtabCtx; /* Context for active vtab connect/create */ VTable **aVTrans; /* Virtual tables with open transactions */ VTable *pDisconnect; /* Disconnect these in next sqlite3_prepare() */ #endif FuncDefHash aFunc; /* Hash table of connection functions */ Hash aCollSeq; /* All collating sequences */ BusyHandler busyHandler; /* Busy callback */ Db aDbStatic[2]; /* Static space for the 2 default backends */ Savepoint *pSavepoint; /* List of active savepoints */ int busyTimeout; /* Busy handler timeout, in msec */ int nSavepoint; /* Number of non-transaction savepoints */ int nStatement; /* Number of nested statement-transactions */ i64 nDeferredCons; /* Net deferred constraints this transaction. */ int *pnBytesFreed; /* If not NULL, increment this in DbFree() */ #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY /* The following variables are all protected by the STATIC_MASTER ** mutex, not by sqlite3.mutex. They are used by code in notify.c. ** ** When X.pUnlockConnection==Y, that means that X is waiting for Y to ** unlock so that it can proceed. ** ** When X.pBlockingConnection==Y, that means that something that X tried ** tried to do recently failed with an SQLITE_LOCKED error due to locks ** held by Y. */ sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */ sqlite3 *pUnlockConnection; /* Connection to watch for unlock */ void *pUnlockArg; /* Argument to xUnlockNotify */ void (*xUnlockNotify)(void **, int); /* Unlock notify callback */ sqlite3 *pNextBlocked; /* Next in list of all blocked connections */ #endif }; /* ** A macro to discover the encoding of a database. */ #define ENC(db) ((db)->aDb[0].pSchema->enc) /* ** Possible values for the sqlite3.flags. */ #define SQLITE_VdbeTrace 0x00000100 /* True to trace VDBE execution */ #define SQLITE_InternChanges 0x00000200 /* Uncommitted Hash table changes */ #define SQLITE_FullColNames 0x00000400 /* Show full column names on SELECT */ #define SQLITE_ShortColNames 0x00000800 /* Show short columns names */ #define SQLITE_CountRows 0x00001000 /* Count rows changed by INSERT, */ /* DELETE, or UPDATE and return */ /* the count using a callback. */ #define SQLITE_NullCallback 0x00002000 /* Invoke the callback once if the */ /* result set is empty */ #define SQLITE_SqlTrace 0x00004000 /* Debug print SQL as it executes */ #define SQLITE_VdbeListing 0x00008000 /* Debug listings of VDBE programs */ #define SQLITE_WriteSchema 0x00010000 /* OK to update SQLITE_MASTER */ /* 0x00020000 Unused */ #define SQLITE_IgnoreChecks 0x00040000 /* Do not enforce check constraints */ #define SQLITE_ReadUncommitted 0x0080000 /* For shared-cache mode */ #define SQLITE_LegacyFileFmt 0x00100000 /* Create new databases in format 1 */ #define SQLITE_FullFSync 0x00200000 /* Use full fsync on the backend */ #define SQLITE_CkptFullFSync 0x00400000 /* Use full fsync for checkpoint */ #define SQLITE_RecoveryMode 0x00800000 /* Ignore schema errors */ #define SQLITE_ReverseOrder 0x01000000 /* Reverse unordered SELECTs */ #define SQLITE_RecTriggers 0x02000000 /* Enable recursive triggers */ #define SQLITE_ForeignKeys 0x04000000 /* Enforce foreign key constraints */ #define SQLITE_AutoIndex 0x08000000 /* Enable automatic indexes */ #define SQLITE_PreferBuiltin 0x10000000 /* Preference to built-in funcs */ #define SQLITE_LoadExtension 0x20000000 /* Enable load_extension */ #define SQLITE_EnableTrigger 0x40000000 /* True to enable triggers */ /* ** Bits of the sqlite3.flags field that are used by the ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface. ** These must be the low-order bits of the flags field. */ #define SQLITE_QueryFlattener 0x01 /* Disable query flattening */ #define SQLITE_ColumnCache 0x02 /* Disable the column cache */ #define SQLITE_IndexSort 0x04 /* Disable indexes for sorting */ #define SQLITE_IndexSearch 0x08 /* Disable indexes for searching */ #define SQLITE_IndexCover 0x10 /* Disable index covering table */ #define SQLITE_GroupByOrder 0x20 /* Disable GROUPBY cover of ORDERBY */ #define SQLITE_FactorOutConst 0x40 /* Disable factoring out constants */ #define SQLITE_IdxRealAsInt 0x80 /* Store REAL as INT in indices */ #define SQLITE_DistinctOpt 0x80 /* DISTINCT using indexes */ #define SQLITE_OptMask 0xff /* Mask of all disablable opts */ /* ** Possible values for the sqlite.magic field. ** The numbers are obtained at random and have no special meaning, other ** than being distinct from one another. */ #define SQLITE_MAGIC_OPEN 0xa029a697 /* Database is open */ #define SQLITE_MAGIC_CLOSED 0x9f3c2d33 /* Database is closed */ #define SQLITE_MAGIC_SICK 0x4b771290 /* Error and awaiting close */ #define SQLITE_MAGIC_BUSY 0xf03b7906 /* Database currently in use */ #define SQLITE_MAGIC_ERROR 0xb5357930 /* An SQLITE_MISUSE error occurred */ /* ** Each SQL function is defined by an instance of the following ** structure. A pointer to this structure is stored in the sqlite.aFunc ** hash table. When multiple functions have the same name, the hash table ** points to a linked list of these structures. */ struct FuncDef { i16 nArg; /* Number of arguments. -1 means unlimited */ u8 iPrefEnc; /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */ u8 flags; /* 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 ** configured using create_function_v2()) and a reference counter. When ** create_function_v2() is called to create a function with a destructor, ** a single object of this type is allocated. FuncDestructor.nRef is set to ** the number of FuncDef objects created (either 1 or 3, depending on whether ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor ** member of each of the new FuncDef objects is set to point to the allocated ** FuncDestructor. ** ** Thereafter, when one of the FuncDef objects is deleted, the reference ** count on this object is decremented. When it reaches 0, the destructor ** is invoked and the FuncDestructor structure freed. */ struct FuncDestructor { int nRef; void (*xDestroy)(void *); void *pUserData; }; /* ** Possible values for FuncDef.flags. Note that the _LENGTH and _TYPEOF ** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG. There ** are assert() statements in the code to verify this. */ #define SQLITE_FUNC_LIKE 0x01 /* Candidate for the LIKE optimization */ #define SQLITE_FUNC_CASE 0x02 /* Case-sensitive LIKE-type function */ #define SQLITE_FUNC_EPHEM 0x04 /* Ephemeral. Delete with VDBE */ #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */ #define SQLITE_FUNC_COUNT 0x10 /* Built-in count(*) aggregate */ #define SQLITE_FUNC_COALESCE 0x20 /* Built-in coalesce() or ifnull() function */ #define SQLITE_FUNC_LENGTH 0x40 /* Built-in length() function */ #define SQLITE_FUNC_TYPEOF 0x80 /* Built-in typeof() function */ /* ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are ** used to create the initializers for the FuncDef structures. ** ** FUNCTION(zName, nArg, iArg, bNC, xFunc) ** Used to create a scalar function definition of a function zName ** implemented by C function xFunc that accepts nArg arguments. The ** value passed as iArg is cast to a (void*) and made available ** as the user-data (sqlite3_user_data()) for the function. If ** argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set. ** ** AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal) ** Used to create an aggregate function definition implemented by ** the C functions xStep and xFinal. The first four parameters ** are interpreted in the same way as the first 4 parameters to ** FUNCTION(). ** ** LIKEFUNC(zName, nArg, pArg, flags) ** Used to create a scalar function definition of a function zName ** that accepts nArg arguments and is implemented by a call to C ** 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_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_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_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \ pArg, 0, xFunc, 0, 0, #zName, 0, 0} #define LIKEFUNC(zName, nArg, arg, flags) \ {nArg, 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} /* ** 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. */ struct Savepoint { char *zName; /* Savepoint name (nul-terminated) */ i64 nDeferredCons; /* Number of deferred fk violations */ Savepoint *pNext; /* Parent savepoint (if any) */ }; /* ** The following are used as the second parameter to sqlite3Savepoint(), ** and as the P1 argument to the OP_Savepoint instruction. */ #define SAVEPOINT_BEGIN 0 #define SAVEPOINT_RELEASE 1 #define SAVEPOINT_ROLLBACK 2 /* ** Each SQLite module (virtual table definition) is defined by an ** instance of the following structure, stored in the sqlite3.aModule ** hash table. */ struct Module { const sqlite3_module *pModule; /* Callback pointers */ const char *zName; /* Name passed to create_module() */ void *pAux; /* pAux passed to create_module() */ void (*xDestroy)(void *); /* Module destructor function */ }; /* ** information about each column of an SQL table is held in an instance ** of this structure. */ struct Column { char *zName; /* Name of this column */ Expr *pDflt; /* Default value of this column */ char *zDflt; /* Original text of the default value */ char *zType; /* Data type for this column */ char *zColl; /* Collating sequence. If NULL, use the default */ u8 notNull; /* True if there is a NOT NULL constraint */ u8 isPrimKey; /* True if this column is part of the PRIMARY KEY */ char affinity; /* One of the SQLITE_AFF_... values */ #ifndef SQLITE_OMIT_VIRTUALTABLE u8 isHidden; /* True if this column is 'hidden' */ #endif }; /* ** A "Collating Sequence" is defined by an instance of the following ** structure. Conceptually, a collating sequence consists of a name and ** a comparison routine that defines the order of that sequence. ** ** There may two separate implementations of the collation function, one ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine ** native byte order. When a collation sequence is invoked, SQLite selects ** the version that will require the least expensive encoding ** translations, if any. ** ** The CollSeq.pUser member variable is an extra parameter that passed in ** as the first argument to the UTF-8 comparison function, xCmp. ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function, ** xCmp16. ** ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the ** collating sequence is undefined. Indices built on an undefined ** collating sequence may not be read or written. */ struct CollSeq { char *zName; /* Name of the collating sequence, UTF-8 encoded */ u8 enc; /* Text encoding handled by xCmp() */ void *pUser; /* First argument to xCmp() */ int (*xCmp)(void*,int, const void*, int, const void*); void (*xDel)(void*); /* Destructor for pUser */ }; /* ** A sort order can be either ASC or DESC. */ #define SQLITE_SO_ASC 0 /* Sort in ascending order */ #define SQLITE_SO_DESC 1 /* Sort in ascending order */ /* ** Column affinity types. ** ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and ** 't' for SQLITE_AFF_TEXT. But we can save a little space and improve ** the speed a little by numbering the values consecutively. ** ** But rather than start with 0 or 1, we begin with 'a'. That way, ** when multiple affinity types are concatenated into a string and ** used as the P4 operand, they will be more readable. ** ** Note also that the numeric types are grouped together so that testing ** for a numeric type is a single comparison. */ #define SQLITE_AFF_TEXT 'a' #define SQLITE_AFF_NONE 'b' #define SQLITE_AFF_NUMERIC 'c' #define SQLITE_AFF_INTEGER 'd' #define SQLITE_AFF_REAL 'e' #define sqlite3IsNumericAffinity(X) ((X)>=SQLITE_AFF_NUMERIC) /* ** The SQLITE_AFF_MASK values masks off the significant bits of an ** affinity value. */ #define SQLITE_AFF_MASK 0x67 /* ** Additional bit values that can be ORed with an affinity without ** changing the affinity. */ #define SQLITE_JUMPIFNULL 0x08 /* jumps if either operand is NULL */ #define SQLITE_STOREP2 0x10 /* Store result in reg[P2] rather than jump */ #define SQLITE_NULLEQ 0x80 /* NULL=NULL */ /* ** An object of this type is created for each virtual table present in ** the database schema. ** ** If the database schema is shared, then there is one instance of this ** structure for each database connection (sqlite3*) that uses the shared ** schema. This is because each database connection requires its own unique ** instance of the sqlite3_vtab* handle used to access the virtual table ** implementation. sqlite3_vtab* handles can not be shared between ** database connections, even when the rest of the in-memory database ** schema is shared, as the implementation often stores the database ** connection handle passed to it via the xConnect() or xCreate() method ** during initialization internally. This database connection handle may ** then be used by the virtual table implementation to access real tables ** within the database. So that they appear as part of the callers ** transaction, these accesses need to be made via the same database ** connection as that used to execute SQL operations on the virtual table. ** ** All VTable objects that correspond to a single table in a shared ** database schema are initially stored in a linked-list pointed to by ** the Table.pVTable member variable of the corresponding Table object. ** When an sqlite3_prepare() operation is required to access the virtual ** table, it searches the list for the VTable that corresponds to the ** database connection doing the preparing so as to use the correct ** sqlite3_vtab* handle in the compiled query. ** ** When an in-memory Table object is deleted (for example when the ** schema is being reloaded for some reason), the VTable objects are not ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed ** immediately. Instead, they are moved from the Table.pVTable list to ** another linked list headed by the sqlite3.pDisconnect member of the ** corresponding sqlite3 structure. They are then deleted/xDisconnected ** next time a statement is prepared using said sqlite3*. This is done ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes. ** Refer to comments above function sqlite3VtabUnlockList() for an ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect ** list without holding the corresponding sqlite3.mutex mutex. ** ** The memory for objects of this type is always allocated by ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as ** the first argument. */ struct VTable { sqlite3 *db; /* Database connection associated with this table */ Module *pMod; /* Pointer to module implementation */ sqlite3_vtab *pVtab; /* Pointer to vtab instance */ int nRef; /* Number of pointers to this structure */ u8 bConstraint; /* True if constraints are supported */ int iSavepoint; /* Depth of the SAVEPOINT stack */ VTable *pNext; /* Next in linked list (see above) */ }; /* ** Each SQL table is represented in memory by an instance of the ** following structure. ** ** Table.zName is the name of the table. The case of the original ** CREATE TABLE statement is stored, but case is not significant for ** comparisons. ** ** Table.nCol is the number of columns in this table. Table.aCol is a ** pointer to an array of Column structures, one for each column. ** ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of ** the column that is that key. Otherwise Table.iPKey is negative. Note ** that the datatype of the PRIMARY KEY must be INTEGER for this field to ** be set. An INTEGER PRIMARY KEY is used as the rowid for each row of ** the table. If a table has no INTEGER PRIMARY KEY, then a random rowid ** is generated for each row of the table. TF_HasPrimaryKey is set if ** the table has any PRIMARY KEY, INTEGER or otherwise. ** ** Table.tnum is the page number for the root BTree page of the table in the ** database file. If Table.iDb is the index of the database table backend ** in sqlite.aDb[]. 0 is for the main database and 1 is for the file that ** holds temporary tables and indices. If TF_Ephemeral is set ** then the table is stored in a file that is automatically deleted ** when the VDBE cursor to the table is closed. In this case Table.tnum ** refers VDBE cursor number that holds the table open, not to the root ** page number. Transient tables are used to hold the results of a ** sub-query that appears instead of a real table name in the FROM clause ** of a SELECT statement. */ struct Table { char *zName; /* Name of the table or view */ int iPKey; /* If not negative, use aCol[iPKey] as the primary key */ int nCol; /* Number of columns in this table */ Column *aCol; /* Information about each column */ Index *pIndex; /* List of SQL indexes on this table. */ int tnum; /* Root BTree node for this table (see note above) */ tRowcnt nRowEst; /* Estimated rows in table - from sqlite_stat1 table */ Select *pSelect; /* NULL for tables. Points to definition if a view. */ u16 nRef; /* Number of pointers to this Table */ u8 tabFlags; /* Mask of TF_* values */ u8 keyConf; /* What to do in case of uniqueness conflict on iPKey */ FKey *pFKey; /* Linked list of all foreign keys in this table */ char *zColAff; /* String defining the affinity of each column */ #ifndef SQLITE_OMIT_CHECK ExprList *pCheck; /* All CHECK constraints */ #endif #ifndef SQLITE_OMIT_ALTERTABLE int addColOffset; /* Offset in CREATE TABLE stmt to add a new column */ #endif #ifndef SQLITE_OMIT_VIRTUALTABLE VTable *pVTable; /* List of VTable objects. */ int nModuleArg; /* Number of arguments to the module */ char **azModuleArg; /* Text of all module args. [0] is module name */ #endif Trigger *pTrigger; /* List of triggers stored in pSchema */ Schema *pSchema; /* Schema that contains this table */ Table *pNextZombie; /* Next on the Parse.pZombieTab list */ }; /* ** Allowed values for Tabe.tabFlags. */ #define TF_Readonly 0x01 /* Read-only system table */ #define TF_Ephemeral 0x02 /* An ephemeral table */ #define TF_HasPrimaryKey 0x04 /* Table has a primary key */ #define TF_Autoincrement 0x08 /* Integer primary key is autoincrement */ #define TF_Virtual 0x10 /* Is a virtual table */ /* ** Test to see whether or not a table is a virtual table. This is ** done as a macro so that it will be optimized out when virtual ** table support is omitted from the build. */ #ifndef SQLITE_OMIT_VIRTUALTABLE # define IsVirtual(X) (((X)->tabFlags & TF_Virtual)!=0) # define IsHiddenColumn(X) ((X)->isHidden) #else # define IsVirtual(X) 0 # define IsHiddenColumn(X) 0 #endif /* ** Each foreign key constraint is an instance of the following structure. ** ** A foreign key is associated with two tables. The "from" table is ** the table that contains the REFERENCES clause that creates the foreign ** key. The "to" table is the table that is named in the REFERENCES clause. ** Consider this example: ** ** CREATE TABLE ex1( ** a INTEGER PRIMARY KEY, ** b INTEGER CONSTRAINT fk1 REFERENCES ex2(x) ** ); ** ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2". ** ** Each REFERENCES clause generates an instance of the following structure ** which is attached to the from-table. The to-table need not exist when ** the from-table is created. The existence of the to-table is not checked. */ struct FKey { Table *pFrom; /* Table containing the REFERENCES clause (aka: Child) */ FKey *pNextFrom; /* Next foreign key in pFrom */ char *zTo; /* Name of table that the key points to (aka: Parent) */ FKey *pNextTo; /* Next foreign key on table named zTo */ FKey *pPrevTo; /* Previous foreign key on table named zTo */ int nCol; /* Number of columns in this key */ /* EV: R-30323-21917 */ u8 isDeferred; /* True if constraint checking is deferred till COMMIT */ u8 aAction[2]; /* ON DELETE and ON UPDATE actions, respectively */ Trigger *apTrigger[2]; /* Triggers for aAction[] actions */ struct sColMap { /* Mapping of columns in pFrom to columns in zTo */ int iFrom; /* Index of column in pFrom */ char *zCol; /* Name of column in zTo. If 0 use PRIMARY KEY */ } aCol[1]; /* One entry for each of nCol column s */ }; /* ** SQLite supports many different ways to resolve a constraint ** error. ROLLBACK processing means that a constraint violation ** causes the operation in process to fail and for the current transaction ** to be rolled back. ABORT processing means the operation in process ** fails and any prior changes from that one operation are backed out, ** but the transaction is not rolled back. FAIL processing means that ** the operation in progress stops and returns an error code. But prior ** changes due to the same operation are not backed out and no rollback ** occurs. IGNORE means that the particular row that caused the constraint ** error is not inserted or updated. Processing continues and no error ** is returned. REPLACE means that preexisting database rows that caused ** a UNIQUE constraint violation are removed so that the new insert or ** update can proceed. Processing continues and no error is reported. ** ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys. ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the ** same as ROLLBACK for DEFERRED keys. SETNULL means that the foreign ** key is set to NULL. CASCADE means that a DELETE or UPDATE of the ** referenced table row is propagated into the row that holds the ** foreign key. ** ** The following symbolic values are used to record which type ** of action to take. */ #define OE_None 0 /* There is no constraint to check */ #define OE_Rollback 1 /* Fail the operation and rollback the transaction */ #define OE_Abort 2 /* Back out changes but do no rollback transaction */ #define OE_Fail 3 /* Stop the operation but leave all prior changes */ #define OE_Ignore 4 /* Ignore the error. Do not do the INSERT or UPDATE */ #define OE_Replace 5 /* Delete existing record, then do INSERT or UPDATE */ #define OE_Restrict 6 /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */ #define OE_SetNull 7 /* Set the foreign key value to NULL */ #define OE_SetDflt 8 /* Set the foreign key value to its default */ #define OE_Cascade 9 /* Cascade the changes */ #define OE_Default 99 /* Do whatever the default action is */ /* ** An instance of the following structure is passed as the first ** argument to sqlite3VdbeKeyCompare and is used to control the ** comparison of the two index keys. */ struct KeyInfo { sqlite3 *db; /* The database connection */ u8 enc; /* Text encoding - one of the SQLITE_UTF* values */ u16 nField; /* Number of entries in aColl[] */ u8 *aSortOrder; /* Sort order for each column. May be NULL */ CollSeq *aColl[1]; /* Collating sequence for each term of the key */ }; /* ** An instance of the following structure holds information about a ** single index record that has already been parsed out into individual ** values. ** ** A record is an object that contains one or more fields of data. ** Records are used to store the content of a table row and to store ** the key of an index. A blob encoding of a record is created by ** the OP_MakeRecord opcode of the VDBE and is disassembled by the ** OP_Column opcode. ** ** This structure holds a record that has already been disassembled ** into its constituent fields. */ struct UnpackedRecord { KeyInfo *pKeyInfo; /* Collation and sort-order information */ u16 nField; /* Number of entries in apMem[] */ u8 flags; /* Boolean settings. UNPACKED_... below */ i64 rowid; /* Used by UNPACKED_PREFIX_SEARCH */ Mem *aMem; /* Values */ }; /* ** Allowed values of UnpackedRecord.flags */ #define UNPACKED_INCRKEY 0x01 /* Make this key an epsilon larger */ #define UNPACKED_PREFIX_MATCH 0x02 /* A prefix match is considered OK */ #define UNPACKED_PREFIX_SEARCH 0x04 /* Ignore final (rowid) field */ /* ** Each SQL index is represented in memory by an ** instance of the following structure. ** ** The columns of the table that are to be indexed are described ** by the aiColumn[] field of this structure. For example, suppose ** we have the following table and index: ** ** CREATE TABLE Ex1(c1 int, c2 int, c3 text); ** CREATE INDEX Ex2 ON Ex1(c3,c1); ** ** In the Table structure describing Ex1, nCol==3 because there are ** three columns in the table. In the Index structure describing ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed. ** The value of aiColumn is {2, 0}. aiColumn[0]==2 because the ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[]. ** The second column to be indexed (c1) has an index of 0 in ** Ex1.aCol[], hence Ex2.aiColumn[1]==0. ** ** The Index.onError field determines whether or not the indexed columns ** must be unique and what to do if they are not. When Index.onError=OE_None, ** it means this is not a unique index. Otherwise it is a unique index ** and the value of Index.onError indicate the which conflict resolution ** algorithm to employ whenever an attempt is made to insert a non-unique ** element. */ struct Index { char *zName; /* Name of this index */ int *aiColumn; /* Which columns are used by this index. 1st is 0 */ tRowcnt *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */ Table *pTable; /* The SQL table being indexed */ char *zColAff; /* String defining the affinity of each column */ Index *pNext; /* The next index associated with the same table */ Schema *pSchema; /* Schema containing this index */ u8 *aSortOrder; /* Array of size Index.nColumn. True==DESC, False==ASC */ char **azColl; /* Array of collation sequence names for index */ int nColumn; /* Number of columns in the table used by this index */ int tnum; /* Page containing root of this index in database file */ u8 onError; /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */ u8 autoIndex; /* True if is automatically created (ex: by UNIQUE) */ u8 bUnordered; /* Use this index for == or IN queries only */ #ifdef SQLITE_ENABLE_STAT3 int nSample; /* Number of elements in aSample[] */ tRowcnt avgEq; /* Average nEq value for key values not in aSample */ IndexSample *aSample; /* Samples of the left-most key */ #endif }; /* ** Each sample stored in the sqlite_stat3 table is represented in memory ** using a structure of this type. See documentation at the top of the ** analyze.c source file for additional information. */ struct IndexSample { union { char *z; /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */ double r; /* Value if eType is SQLITE_FLOAT */ i64 i; /* Value if eType is SQLITE_INTEGER */ } u; u8 eType; /* SQLITE_NULL, SQLITE_INTEGER ... etc. */ int nByte; /* Size in byte of text or blob. */ tRowcnt nEq; /* Est. number of rows where the key equals this sample */ tRowcnt nLt; /* Est. number of rows where key is less than this sample */ tRowcnt nDLt; /* Est. number of distinct keys less than this sample */ }; /* ** Each token coming out of the lexer is an instance of ** this structure. Tokens are also used as part of an expression. ** ** Note if Token.z==0 then Token.dyn and Token.n are undefined and ** may contain random values. Do not make any assumptions about Token.dyn ** and Token.n when Token.z==0. */ struct Token { const char *z; /* Text of the token. Not NULL-terminated! */ unsigned int n; /* Number of characters in this token */ }; /* ** An instance of this structure contains information needed to generate ** code for a SELECT that contains aggregate functions. ** ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a ** pointer to this structure. The Expr.iColumn field is the index in ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate ** code for that node. ** ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the ** original Select structure that describes the SELECT statement. These ** fields do not need to be freed when deallocating the AggInfo structure. */ struct AggInfo { u8 directMode; /* Direct rendering mode means take data directly ** from source tables rather than from accumulators */ u8 useSortingIdx; /* In direct mode, reference the sorting index rather ** than the source table */ int sortingIdx; /* Cursor number of the sorting index */ int sortingIdxPTab; /* Cursor number of pseudo-table */ int nSortingColumn; /* Number of columns in the sorting index */ ExprList *pGroupBy; /* The group by clause */ struct AggInfo_col { /* For each column used in source tables */ Table *pTab; /* Source table */ int iTable; /* Cursor number of the source table */ int iColumn; /* Column number within the source table */ int iSorterColumn; /* Column number in the sorting index */ int iMem; /* Memory location that acts as accumulator */ Expr *pExpr; /* The original expression */ } *aCol; int nColumn; /* Number of used entries in aCol[] */ int nAccumulator; /* Number of columns that show through to the output. ** Additional columns are used only as parameters to ** aggregate functions */ struct AggInfo_func { /* For each aggregate function */ Expr *pExpr; /* Expression encoding the function */ FuncDef *pFunc; /* The aggregate function implementation */ int iMem; /* Memory location that acts as accumulator */ int iDistinct; /* Ephemeral table used to enforce DISTINCT */ } *aFunc; int nFunc; /* Number of entries in aFunc[] */ }; /* ** The datatype ynVar is a signed integer, either 16-bit or 32-bit. ** Usually it is 16-bits. But if SQLITE_MAX_VARIABLE_NUMBER is greater ** than 32767 we have to make it 32-bit. 16-bit is preferred because ** it uses less memory in the Expr object, which is a big memory user ** in systems with lots of prepared statements. And few applications ** need more than about 10 or 20 variables. But some extreme users want ** to have prepared statements with over 32767 variables, and for them ** the option is available (at compile-time). */ #if SQLITE_MAX_VARIABLE_NUMBER<=32767 typedef i16 ynVar; #else typedef int ynVar; #endif /* ** Each node of an expression in the parse tree is an instance ** of this structure. ** ** Expr.op is the opcode. The integer parser token codes are reused ** as opcodes here. For example, the parser defines TK_GE to be an integer ** code representing the ">=" operator. This same integer code is reused ** to represent the greater-than-or-equal-to operator in the expression ** tree. ** ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB, ** or TK_STRING), then Expr.token contains the text of the SQL literal. If ** the expression is a variable (TK_VARIABLE), then Expr.token contains the ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION), ** then Expr.token contains the name of the function. ** ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a ** binary operator. Either or both may be NULL. ** ** Expr.x.pList is a list of arguments if the expression is an SQL function, ** a CASE expression or an IN expression of the form " IN (, ...)". ** Expr.x.pSelect is used if the expression is a sub-select or an expression of ** the form " IN (SELECT ...)". If the EP_xIsSelect bit is set in the ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is ** valid. ** ** An expression of the form ID or ID.ID refers to a column in a table. ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is ** the integer cursor number of a VDBE cursor pointing to that table and ** Expr.iColumn is the column number for the specific column. If the ** expression is used as a result in an aggregate SELECT, then the ** value is also stored in the Expr.iAgg column in the aggregate so that ** it can be accessed after all aggregates are computed. ** ** If the expression is an unbound variable marker (a question mark ** character '?' in the original SQL) then the Expr.iTable holds the index ** number for that variable. ** ** If the expression is a subquery then Expr.iColumn holds an integer ** register number containing the result of the subquery. If the ** subquery gives a constant result, then iTable is -1. If the subquery ** gives a different answer at different times during statement processing ** then iTable is the address of a subroutine that computes the subquery. ** ** If the Expr is of type OP_Column, and the table it is selecting from ** is a disk table or the "old.*" pseudo-table, then pTab points to the ** corresponding table definition. ** ** ALLOCATION NOTES: ** ** Expr objects can use a lot of memory space in database schema. To ** help reduce memory requirements, sometimes an Expr object will be ** truncated. And to reduce the number of memory allocations, sometimes ** two or more Expr objects will be stored in a single memory allocation, ** together with Expr.zToken strings. ** ** If the EP_Reduced and EP_TokenOnly flags are set when ** an Expr object is truncated. When EP_Reduced is set, then all ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees ** are contained within the same memory allocation. Note, however, that ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately ** allocated, regardless of whether or not EP_Reduced is set. */ struct Expr { u8 op; /* Operation performed by this node */ char affinity; /* The affinity of the column or 0 if not a column */ u16 flags; /* Various flags. EP_* See below */ union { char *zToken; /* Token value. Zero terminated and dequoted */ int iValue; /* Non-negative integer value if EP_IntValue */ } u; /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no ** space is allocated for the fields below this point. An attempt to ** access them will result in a segfault or malfunction. *********************************************************************/ Expr *pLeft; /* Left subnode */ Expr *pRight; /* Right subnode */ union { ExprList *pList; /* Function arguments or in " IN ( IN (