System.Data.SQLite
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Overview
Comment:Initial revision
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | descendants | trunk | sourceforge
Files: files | file ages | folders
SHA1: ec237b012300b80fb16dc2b3d970a6d870d03e07
User & Date: rmsimpson 2005-03-01 16:04:25
Original Comment: Initial revision
Original User & Date: rmsimpson 2005-03-01 16:04:26
Context
2005-03-01
17:32
Initial revision check-in: 5b6332ffaa user: rmsimpson tags: sourceforge
16:04
Initial checkin Closed-Leaf check-in: 3ca8c53212 user: rmsimpson tags: start, sourceforge
16:04
Initial revision check-in: ec237b0123 user: rmsimpson tags: trunk, sourceforge
Changes
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<project SchemaVersion="1.3">
    <assemblies>
        <assembly location="..\System.Data.SQLite\bin\Release\System.Data.SQLite.dll" documentation="..\System.Data.SQLite\bin\Release\System.Data.SQLite.xml" />
    </assemblies>
    <documenters>
        <documenter name="JavaDoc">
            <property name="OutputDirectory" value=".\doc\" />
        </documenter>
        <documenter name="LaTeX">
            <property name="OutputDirectory" value=".\doc\" />
            <property name="TextFileFullName" value="Documentation.tex" />
            <property name="TexFileBaseName" value="Documentation" />
            <property name="LatexCompiler" value="latex" />
            <property name="TexFileFullPath" value=".\doc\Documentation.tex" />
        </documenter>
        <documenter name="LinearHtml">
            <property name="OutputDirectory" value=".\doc\" />
            <property name="Title" value="An NDoc Documented Class Library" />
        </documenter>
        <documenter name="MSDN">
            <property name="OutputDirectory" value="c:\src\SQLite.NET\Doc\" />
            <property name="HtmlHelpName" value="SQLite.NET" />
            <property name="Title" value="SQLite.NET Class Library" />
            <property name="OutputTarget" value="HtmlHelp" />
            <property name="IncludeFavorites" value="True" />
            <property name="AssemblyVersionInfo" value="AssemblyVersion" />
            <property name="FeedbackEmailAddress" value="robert@blackcastlesoft.com" />
            <property name="Preliminary" value="True" />
            <property name="IncludeDefaultThreadSafety" value="False" />
            <property name="CleanIntermediates" value="True" />
        </documenter>
        <documenter name="MSDN 2003">
            <property name="OutputDirectory" value=".\doc\" />
            <property name="Title" value="An NDoc Documented Class Library" />
        </documenter>
        <documenter name="VS.NET 2003">
            <property name="OutputDirectory" value=".\doc\" />
            <property name="HtmlHelpName" value="Documentation" />
            <property name="Title" value="An NDoc documented library" />
        </documenter>
        <documenter name="XML">
            <property name="OutputFile" value=".\doc\doc.xml" />
        </documenter>
    </documenters>
</project>

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Building documentation...
Initializing...
Merging XML documentation...
Building file mapping...
Loading XSLT files...
    namespace.xslt
    namespacehierarchy.xslt
    type.xslt
    typehierarchy.xslt
    allmembers.xslt
    individualmembers.xslt
    event.xslt
    member.xslt
    memberoverload.xslt
    property.xslt
    field.xslt
    htmlcontents.xslt
Generating HTML pages...
System.Data.SQLite.html
System.Data.SQLiteHierarchy.html
System.Data.SQLite.DateTimeFormat.html
System.Data.SQLite.FunctionType.html
System.Data.SQLite.SQLiteCommand.html
System.Data.SQLite.SQLiteCommandMembers.html
System.Data.SQLite.SQLiteCommandConstructor.html
System.Data.SQLite.SQLiteCommandConstructor1.html
System.Data.SQLite.SQLiteCommandConstructor2.html
System.Data.SQLite.SQLiteCommandConstructor3.html
System.Data.SQLite.SQLiteCommandConstructor4.html
System.Data.SQLite.SQLiteCommandProperties.html
System.Data.SQLite.SQLiteCommand.CommandText.html
System.Data.SQLite.SQLiteCommand.CommandTimeout.html
System.Data.SQLite.SQLiteCommand.CommandType.html
System.Data.SQLite.SQLiteCommand.DesignTimeVisible.html
System.Data.SQLite.SQLiteCommand.UpdatedRowSource.html
System.Data.SQLite.SQLiteCommandMethods.html
System.Data.SQLite.SQLiteCommand.Cancel.html
System.Data.SQLite.SQLiteCommand.ExecuteNonQuery.html
System.Data.SQLite.SQLiteCommand.ExecuteScalar.html
System.Data.SQLite.SQLiteCommand.Prepare.html
System.Data.SQLite.SQLiteCommandBuilder.html
System.Data.SQLite.SQLiteCommandBuilderMembers.html
System.Data.SQLite.SQLiteCommandBuilderConstructor.html
System.Data.SQLite.SQLiteCommandBuilderConstructor1.html
System.Data.SQLite.SQLiteCommandBuilderConstructor2.html
System.Data.SQLite.SQLiteConnection.html
System.Data.SQLite.SQLiteConnectionMembers.html
System.Data.SQLite.SQLiteConnectionConstructor.html
System.Data.SQLite.SQLiteConnectionConstructor1.html
System.Data.SQLite.SQLiteConnectionConstructor2.html
System.Data.SQLite.SQLiteConnectionConstructor3.html
System.Data.SQLite.SQLiteConnectionProperties.html
System.Data.SQLite.SQLiteConnection.ConnectionString.html
System.Data.SQLite.SQLiteConnection.Database.html
System.Data.SQLite.SQLiteConnection.DataSource.html
System.Data.SQLite.SQLiteConnection.ServerVersion.html
System.Data.SQLite.SQLiteConnection.State.html
System.Data.SQLite.SQLiteConnectionMethods.html
System.Data.SQLite.SQLiteConnection.ChangeDatabase.html
System.Data.SQLite.SQLiteConnection.Clone.html
System.Data.SQLite.SQLiteConnection.Close.html
System.Data.SQLite.SQLiteConnection.GetSchema_overloads.html
System.Data.SQLite.SQLiteConnection.GetSchema_overload_1.html
System.Data.SQLite.SQLiteConnection.GetSchema_overload_2.html
System.Data.SQLite.SQLiteConnection.GetSchema_overload_3.html
System.Data.SQLite.SQLiteConnection.Open.html
System.Data.SQLite.SQLiteConnectionEvents.html
System.Data.SQLite.SQLiteConnection.StateChange.html
System.Data.SQLite.SQLiteConnectionStringBuilder.html
System.Data.SQLite.SQLiteConnectionStringBuilderMembers.html
System.Data.SQLite.SQLiteConnectionStringBuilderConstructor.html
System.Data.SQLite.SQLiteConnectionStringBuilderConstructor1.html
System.Data.SQLite.SQLiteConnectionStringBuilderConstructor2.html
System.Data.SQLite.SQLiteConnectionStringBuilderProperties.html
System.Data.SQLite.SQLiteConnectionStringBuilder.CacheSize.html
System.Data.SQLite.SQLiteConnectionStringBuilder.DataSource.html
System.Data.SQLite.SQLiteConnectionStringBuilder.DateTimeFormat.html
System.Data.SQLite.SQLiteConnectionStringBuilder.PageSize.html
System.Data.SQLite.SQLiteConnectionStringBuilder.SyncMode.html
System.Data.SQLite.SQLiteConnectionStringBuilder.UseUTF16Encoding.html
System.Data.SQLite.SQLiteConnectionStringBuilder.Version.html
System.Data.SQLite.SQLiteConvert.html
System.Data.SQLite.SQLiteConvertMembers.html
System.Data.SQLite.SQLiteConvertMethods.html
System.Data.SQLite.SQLiteConvert.Split.html
System.Data.SQLite.SQLiteConvert.ToDateTime.html
System.Data.SQLite.SQLiteConvert.ToString_overloads.html
System.Data.SQLite.SQLiteConvert.ToString_overload_2.html
System.Data.SQLite.SQLiteConvert.ToString_overload_1.html
System.Data.SQLite.SQLiteConvert.ToUTF8_overloads.html
System.Data.SQLite.SQLiteConvert.ToUTF8_overload_2.html
System.Data.SQLite.SQLiteConvert.ToUTF8_overload_1.html
System.Data.SQLite.SQLiteConvert.TryToDateTime.html
System.Data.SQLite.SQLiteDataAdapter.html
System.Data.SQLite.SQLiteDataAdapterMembers.html
System.Data.SQLite.SQLiteDataAdapterConstructor.html
System.Data.SQLite.SQLiteDataAdapterConstructor1.html
System.Data.SQLite.SQLiteDataAdapterConstructor2.html
System.Data.SQLite.SQLiteDataAdapterConstructor3.html
System.Data.SQLite.SQLiteDataAdapterConstructor4.html
System.Data.SQLite.SQLiteDataReader.html
System.Data.SQLite.SQLiteDataReaderMembers.html
System.Data.SQLite.SQLiteDataReaderProperties.html
System.Data.SQLite.SQLiteDataReader.Depth.html
System.Data.SQLite.SQLiteDataReader.FieldCount.html
System.Data.SQLite.SQLiteDataReader.HasRows.html
System.Data.SQLite.SQLiteDataReader.IsClosed.html
System.Data.SQLite.SQLiteDataReaderItem.html
System.Data.SQLite.SQLiteDataReader.Item2.html
System.Data.SQLite.SQLiteDataReader.Item1.html
System.Data.SQLite.SQLiteDataReader.RecordsAffected.html
System.Data.SQLite.SQLiteDataReaderMethods.html
System.Data.SQLite.SQLiteDataReader.Close.html
System.Data.SQLite.SQLiteDataReader.Dispose.html
System.Data.SQLite.SQLiteDataReader.GetBoolean.html
System.Data.SQLite.SQLiteDataReader.GetByte.html
System.Data.SQLite.SQLiteDataReader.GetBytes.html
System.Data.SQLite.SQLiteDataReader.GetChar.html
System.Data.SQLite.SQLiteDataReader.GetChars.html
System.Data.SQLite.SQLiteDataReader.GetDataTypeName.html
System.Data.SQLite.SQLiteDataReader.GetDateTime.html
System.Data.SQLite.SQLiteDataReader.GetDecimal.html
System.Data.SQLite.SQLiteDataReader.GetDouble.html
System.Data.SQLite.SQLiteDataReader.GetEnumerator.html
System.Data.SQLite.SQLiteDataReader.GetFieldType.html
System.Data.SQLite.SQLiteDataReader.GetFloat.html
System.Data.SQLite.SQLiteDataReader.GetGuid.html
System.Data.SQLite.SQLiteDataReader.GetInt16.html
System.Data.SQLite.SQLiteDataReader.GetInt32.html
System.Data.SQLite.SQLiteDataReader.GetInt64.html
System.Data.SQLite.SQLiteDataReader.GetName.html
System.Data.SQLite.SQLiteDataReader.GetOrdinal.html
System.Data.SQLite.SQLiteDataReader.GetSchemaTable.html
System.Data.SQLite.SQLiteDataReader.GetString.html
System.Data.SQLite.SQLiteDataReader.GetValue.html
System.Data.SQLite.SQLiteDataReader.GetValues.html
System.Data.SQLite.SQLiteDataReader.IsDBNull.html
System.Data.SQLite.SQLiteDataReader.NextResult.html
System.Data.SQLite.SQLiteDataReader.Read.html
System.Data.SQLite.SQLiteException.html
System.Data.SQLite.SQLiteExceptionMembers.html
System.Data.SQLite.SQLiteFactory.html
System.Data.SQLite.SQLiteFactoryMembers.html
System.Data.SQLite.SQLiteFactoryConstructor.html
System.Data.SQLite.SQLiteFactoryFields.html
System.Data.SQLite.SQLiteFactory.Instance.html
System.Data.SQLite.SQLiteFactoryProperties.html
System.Data.SQLite.SQLiteFactory.SupportedClasses.html
System.Data.SQLite.SQLiteFactoryMethods.html
System.Data.SQLite.SQLiteFactory.CreateCommand.html
System.Data.SQLite.SQLiteFactory.CreateCommandBuilder.html
System.Data.SQLite.SQLiteFactory.CreateConnection.html
System.Data.SQLite.SQLiteFactory.CreateConnectionStringBuilder.html
System.Data.SQLite.SQLiteFactory.CreateDataAdapter.html
System.Data.SQLite.SQLiteFactory.CreateParameter.html
System.Data.SQLite.SQLiteFunction.html
System.Data.SQLite.SQLiteFunctionMembers.html
System.Data.SQLite.SQLiteFunctionConstructor.html
System.Data.SQLite.SQLiteFunctionProperties.html
System.Data.SQLite.SQLiteFunction.SQLiteConvert.html
System.Data.SQLite.SQLiteFunctionMethods.html
System.Data.SQLite.SQLiteFunction.Compare.html
System.Data.SQLite.SQLiteFunction.Dispose_overloads.html
System.Data.SQLite.SQLiteFunction.Dispose_overload_2.html
System.Data.SQLite.SQLiteFunction.Dispose_overload_1.html
System.Data.SQLite.SQLiteFunction.Final.html
System.Data.SQLite.SQLiteFunction.Invoke.html
System.Data.SQLite.SQLiteFunction.RegisterFunction.html
System.Data.SQLite.SQLiteFunction.Step.html
System.Data.SQLite.SQLiteFunctionAttribute.html
System.Data.SQLite.SQLiteFunctionAttributeMembers.html
System.Data.SQLite.SQLiteFunctionAttributeConstructor.html
System.Data.SQLite.SQLiteFunctionAttributeFields.html
System.Data.SQLite.SQLiteFunctionAttribute.Arguments.html
System.Data.SQLite.SQLiteFunctionAttribute.FuncType.html
System.Data.SQLite.SQLiteFunctionAttribute.Name.html
System.Data.SQLite.SQLiteParameter.html
System.Data.SQLite.SQLiteParameterMembers.html
System.Data.SQLite.SQLiteParameterConstructor.html
System.Data.SQLite.SQLiteParameterConstructor1.html
System.Data.SQLite.SQLiteParameterConstructor2.html
System.Data.SQLite.SQLiteParameterConstructor3.html
System.Data.SQLite.SQLiteParameterConstructor4.html
System.Data.SQLite.SQLiteParameterConstructor5.html
System.Data.SQLite.SQLiteParameterConstructor6.html
System.Data.SQLite.SQLiteParameterConstructor7.html
System.Data.SQLite.SQLiteParameterConstructor8.html
System.Data.SQLite.SQLiteParameterConstructor9.html
System.Data.SQLite.SQLiteParameterConstructor10.html
System.Data.SQLite.SQLiteParameterConstructor11.html
System.Data.SQLite.SQLiteParameterConstructor12.html
System.Data.SQLite.SQLiteParameterConstructor13.html
System.Data.SQLite.SQLiteParameterConstructor14.html
System.Data.SQLite.SQLiteParameterProperties.html
System.Data.SQLite.SQLiteParameter.DbType.html
System.Data.SQLite.SQLiteParameter.Direction.html
System.Data.SQLite.SQLiteParameter.IsNullable.html
System.Data.SQLite.SQLiteParameter.Offset.html
System.Data.SQLite.SQLiteParameter.ParameterName.html
System.Data.SQLite.SQLiteParameter.Size.html
System.Data.SQLite.SQLiteParameter.SourceColumn.html
System.Data.SQLite.SQLiteParameter.SourceColumnNullMapping.html
System.Data.SQLite.SQLiteParameter.SourceVersion.html
System.Data.SQLite.SQLiteParameter.Value.html
System.Data.SQLite.SQLiteParameterMethods.html
System.Data.SQLite.SQLiteParameter.CopyTo.html
System.Data.SQLite.SQLiteParameter.ResetDbType.html
System.Data.SQLite.SQLiteParameterCollection.html
System.Data.SQLite.SQLiteParameterCollectionMembers.html
System.Data.SQLite.SQLiteParameterCollectionProperties.html
System.Data.SQLite.SQLiteParameterCollection.Count.html
System.Data.SQLite.SQLiteParameterCollection.IsFixedSize.html
System.Data.SQLite.SQLiteParameterCollection.IsReadOnly.html
System.Data.SQLite.SQLiteParameterCollection.IsSynchronized.html
System.Data.SQLite.SQLiteParameterCollection.SyncRoot.html
System.Data.SQLite.SQLiteParameterCollectionMethods.html
System.Data.SQLite.SQLiteParameterCollection.Add_overloads.html
System.Data.SQLite.SQLiteParameterCollection.Add_overload_4.html
System.Data.SQLite.SQLiteParameterCollection.Add_overload_5.html
System.Data.SQLite.SQLiteParameterCollection.Add_overload_3.html
System.Data.SQLite.SQLiteParameterCollection.Add_overload_2.html
System.Data.SQLite.SQLiteParameterCollection.Add_overload_1.html
System.Data.SQLite.SQLiteParameterCollection.AddRange_overloads.html
System.Data.SQLite.SQLiteParameterCollection.AddRange_overload_2.html
System.Data.SQLite.SQLiteParameterCollection.AddRange_overload_1.html
System.Data.SQLite.SQLiteParameterCollection.Clear.html
System.Data.SQLite.SQLiteParameterCollection.Contains_overloads.html
System.Data.SQLite.SQLiteParameterCollection.Contains_overload_2.html
System.Data.SQLite.SQLiteParameterCollection.Contains_overload_1.html
System.Data.SQLite.SQLiteParameterCollection.CopyTo.html
System.Data.SQLite.SQLiteParameterCollection.GetEnumerator.html
System.Data.SQLite.SQLiteParameterCollection.IndexOf_overloads.html
System.Data.SQLite.SQLiteParameterCollection.IndexOf_overload_2.html
System.Data.SQLite.SQLiteParameterCollection.IndexOf_overload_1.html
System.Data.SQLite.SQLiteParameterCollection.Insert.html
System.Data.SQLite.SQLiteParameterCollection.Remove.html
System.Data.SQLite.SQLiteParameterCollection.RemoveAt_overloads.html
System.Data.SQLite.SQLiteParameterCollection.RemoveAt_overload_2.html
System.Data.SQLite.SQLiteParameterCollection.RemoveAt_overload_1.html
System.Data.SQLite.SQLiteTransaction.html
System.Data.SQLite.SQLiteTransactionMembers.html
System.Data.SQLite.SQLiteTransactionProperties.html
System.Data.SQLite.SQLiteTransaction.IsolationLevel.html
System.Data.SQLite.SQLiteTransactionMethods.html
System.Data.SQLite.SQLiteTransaction.Commit.html
System.Data.SQLite.SQLiteTransaction.Dispose.html
System.Data.SQLite.SQLiteTransaction.Rollback.html
System.Data.SQLite.SyncMode.html
System.Data.SQLite.TypeAffinity.html
Compiling HTML Help file...
Compiling Html Help file
Microsoft HTML Help Compiler 4.74.8702

Compiling c:\src\SQLite.NET\Doc\ndoc_msdn_temp\SQLite.NET.chm


Compile time: 0 minutes, 3 seconds
233	Topics
1,346	Local links
0	Internet links
8	Graphics


Created c:\src\SQLite.NET\Doc\ndoc_msdn_temp\SQLite.NET.chm, 135,017 bytes
Compression decreased file by 734,402 bytes.

Html Help compile complete
Done.

Added SQLite.Interop/SQLite.Interop.vcproj.

























































































































































































































































































































































































































































































































































































































































































































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<?xml version="1.0" encoding="Windows-1252"?>
<VisualStudioProject
	ProjectType="Visual C++"
	Version="8.00"
	Name="SQLite.Interop"
	ProjectGUID="{10B51CE8-A838-44DE-BD82-B658F0296F80}"
	RootNamespace="SQLite.Interop"
	Keyword="Win32Proj"
	>
	<Platforms>
		<Platform
			Name="Win32"
		/>
	</Platforms>
	<ToolFiles>
	</ToolFiles>
	<Configurations>
		<Configuration
			Name="Debug|Win32"
			OutputDirectory="Debug"
			IntermediateDirectory="Debug"
			ConfigurationType="2"
			CharacterSet="2"
			>
			<Tool
				Name="VCPreBuildEventTool"
			/>
			<Tool
				Name="VCCustomBuildTool"
			/>
			<Tool
				Name="VCXMLDataGeneratorTool"
			/>
			<Tool
				Name="VCWebServiceProxyGeneratorTool"
			/>
			<Tool
				Name="VCMIDLTool"
			/>
			<Tool
				Name="VCCLCompilerTool"
				Optimization="0"
				PreprocessorDefinitions="WIN32;_DEBUG;_WINDOWS;_USRDLL;_CRT_SECURE_NO_DEPRECATE;NO_TCL;THREADSAFE"
				StringPooling="true"
				ExceptionHandling="0"
				BasicRuntimeChecks="3"
				RuntimeLibrary="1"
				EnableFunctionLevelLinking="true"
				UsePrecompiledHeader="0"
				WarningLevel="1"
				DebugInformationFormat="3"
			/>
			<Tool
				Name="VCManagedResourceCompilerTool"
			/>
			<Tool
				Name="VCResourceCompilerTool"
			/>
			<Tool
				Name="VCPreLinkEventTool"
			/>
			<Tool
				Name="VCLinkerTool"
				OutputFile="$(OutDir)/$(ProjectName).dll"
				LinkIncremental="1"
				GenerateManifest="false"
				GenerateDebugInformation="true"
				ProgramDatabaseFile="$(OutDir)/$(ProjectName).pdb"
				SubSystem="2"
				ImportLibrary="$(OutDir)/$(ProjectName).lib"
				TargetMachine="1"
			/>
			<Tool
				Name="VCALinkTool"
			/>
			<Tool
				Name="VCManifestTool"
			/>
			<Tool
				Name="VCXDCMakeTool"
			/>
			<Tool
				Name="VCBscMakeTool"
			/>
			<Tool
				Name="VCFxCopTool"
			/>
			<Tool
				Name="VCAppVerifierTool"
			/>
			<Tool
				Name="VCWebDeploymentTool"
			/>
			<Tool
				Name="VCPostBuildEventTool"
			/>
		</Configuration>
		<Configuration
			Name="Release|Win32"
			OutputDirectory="Release"
			IntermediateDirectory="Release"
			ConfigurationType="2"
			CharacterSet="2"
			WholeProgramOptimization="0"
			>
			<Tool
				Name="VCPreBuildEventTool"
			/>
			<Tool
				Name="VCCustomBuildTool"
			/>
			<Tool
				Name="VCXMLDataGeneratorTool"
			/>
			<Tool
				Name="VCWebServiceProxyGeneratorTool"
			/>
			<Tool
				Name="VCMIDLTool"
			/>
			<Tool
				Name="VCCLCompilerTool"
				Optimization="2"
				FavorSizeOrSpeed="1"
				PreprocessorDefinitions="WIN32;NDEBUG;_WINDOWS;_USRDLL;_CRT_SECURE_NO_DEPRECATE;NO_TCL;THREADSAFE"
				StringPooling="true"
				ExceptionHandling="0"
				RuntimeLibrary="0"
				BufferSecurityCheck="false"
				EnableFunctionLevelLinking="true"
				UsePrecompiledHeader="0"
				WarningLevel="1"
				DebugInformationFormat="0"
			/>
			<Tool
				Name="VCManagedResourceCompilerTool"
			/>
			<Tool
				Name="VCResourceCompilerTool"
			/>
			<Tool
				Name="VCPreLinkEventTool"
			/>
			<Tool
				Name="VCLinkerTool"
				OutputFile="$(OutDir)/$(ProjectName).dll"
				LinkIncremental="1"
				GenerateManifest="false"
				SubSystem="2"
				OptimizeReferences="2"
				EnableCOMDATFolding="2"
				ImportLibrary="$(OutDir)/$(ProjectName).lib"
				TargetMachine="1"
			/>
			<Tool
				Name="VCALinkTool"
			/>
			<Tool
				Name="VCManifestTool"
			/>
			<Tool
				Name="VCXDCMakeTool"
			/>
			<Tool
				Name="VCBscMakeTool"
			/>
			<Tool
				Name="VCFxCopTool"
			/>
			<Tool
				Name="VCAppVerifierTool"
			/>
			<Tool
				Name="VCWebDeploymentTool"
			/>
			<Tool
				Name="VCPostBuildEventTool"
			/>
		</Configuration>
	</Configurations>
	<References>
	</References>
	<Files>
		<Filter
			Name="Source Files"
			Filter="cpp;c;cxx;def;odl;idl;hpj;bat;asm;asmx"
			UniqueIdentifier="{4FC737F1-C7A5-4376-A066-2A32D752A2FF}"
			>
			<File
				RelativePath=".\src\alter.c"
				>
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				>
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			<File
				RelativePath=".\src\auth.c"
				>
			</File>
			<File
				RelativePath=".\src\btree.c"
				>
			</File>
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				RelativePath=".\src\build.c"
				>
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				>
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				RelativePath=".\src\delete.c"
				>
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			<File
				RelativePath=".\src\expr.c"
				>
			</File>
			<File
				RelativePath=".\src\func.c"
				>
			</File>
			<File
				RelativePath=".\src\hash.c"
				>
			</File>
			<File
				RelativePath=".\src\insert.c"
				>
			</File>
			<File
				RelativePath=".\src\legacy.c"
				>
			</File>
			<File
				RelativePath=".\src\main.c"
				>
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			<File
				RelativePath=".\src\opcodes.c"
				>
			</File>
			<File
				RelativePath=".\src\os_unix.c"
				>
			</File>
			<File
				RelativePath=".\src\os_win.c"
				>
			</File>
			<File
				RelativePath=".\src\pager.c"
				>
			</File>
			<File
				RelativePath=".\src\parse.c"
				>
			</File>
			<File
				RelativePath=".\src\pragma.c"
				>
			</File>
			<File
				RelativePath=".\src\printf.c"
				>
			</File>
			<File
				RelativePath=".\src\random.c"
				>
			</File>
			<File
				RelativePath=".\src\select.c"
				>
			</File>
			<File
				RelativePath=".\src\table.c"
				>
			</File>
			<File
				RelativePath=".\src\tclsqlite.c"
				>
			</File>
			<File
				RelativePath=".\src\tokenize.c"
				>
			</File>
			<File
				RelativePath=".\src\trigger.c"
				>
			</File>
			<File
				RelativePath=".\src\update.c"
				>
			</File>
			<File
				RelativePath=".\src\utf.c"
				>
			</File>
			<File
				RelativePath=".\src\util.c"
				>
			</File>
			<File
				RelativePath=".\src\vacuum.c"
				>
			</File>
			<File
				RelativePath=".\src\vdbe.c"
				>
			</File>
			<File
				RelativePath=".\src\vdbeapi.c"
				>
			</File>
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				RelativePath=".\src\vdbeaux.c"
				>
			</File>
			<File
				RelativePath=".\src\vdbemem.c"
				>
			</File>
			<File
				RelativePath=".\src\where.c"
				>
			</File>
		</Filter>
		<Filter
			Name="Header Files"
			Filter="h;hpp;hxx;hm;inl;inc;xsd"
			UniqueIdentifier="{93995380-89BD-4b04-88EB-625FBE52EBFB}"
			>
			<File
				RelativePath=".\interop.h"
				FileType="0"
				>
			</File>
			<File
				RelativePath=".\src\sqlite3.h"
				>
			</File>
		</Filter>
	</Files>
	<Globals>
	</Globals>
</VisualStudioProject>

Added SQLite.Interop/interop.h.





























































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































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/*
   This interop file must be included at or near the top of the select.c file of the SQLite3 source distribution.

   generateColumnNames() in the select.c must be renamed to _generateColumnNames

*/
#include "os.h"
#include "sqliteint.h"

static void generateColumnTypes(
  Parse *pParse,      /* Parser context */
  SrcList *pTabList,  /* List of tables */
  ExprList *pEList    /* Expressions defining the result set */
);

static void _generateColumnNames(
  Parse *pParse,      /* Parser context */
  SrcList *pTabList,  /* List of tables */
  ExprList *pEList    /* Expressions defining the result set */
);

/*
** Generate code that will tell the VDBE the names of columns
** in the result set.  This information is used to provide the
** azCol[] values in the callback.
*/
static void generateColumnNames(
  Parse *pParse,      /* Parser context */
  SrcList *pTabList,  /* List of tables */
  ExprList *pEList    /* Expressions defining the result set */
){
  Vdbe *v = pParse->pVdbe;
  int i, j;
  sqlite3 *db = pParse->db;
  int fullNames, shortNames;
  int realNames;                                     /*** ADDED - SQLite.Interop ***/

  realNames = (db->flags & 0x01000000)!=0;           /*** ADDED - SQLite.Interop ***/
  if (!realNames) // Default to normal Sqlite3       /*** ADDED - SQLite.Interop ***/
  {                                                  /*** ADDED - SQLite.Interop ***/
    _generateColumnNames(pParse, pTabList, pEList);  /*** ADDED - SQLite.Interop ***/
    return;                                          /*** ADDED - SQLite.Interop ***/
  }                                                  /*** ADDED - SQLite.Interop ***/

#ifndef SQLITE_OMIT_EXPLAIN
  /* If this is an EXPLAIN, skip this step */
  if( pParse->explain ){
    return;
  }
#endif

  assert( v!=0 );
  if( pParse->colNamesSet || v==0 || sqlite3_malloc_failed ) return;
  pParse->colNamesSet = 1;
  fullNames = (db->flags & SQLITE_FullColNames)!=0;
  shortNames = (db->flags & SQLITE_ShortColNames)!=0;
  if (realNames) fullNames = 1;                      /*** ADDED - SQLite.Interop ***/

  sqlite3VdbeSetNumCols(v, pEList->nExpr);
  for(i=0; i<pEList->nExpr; i++){
    Expr *p;
    p = pEList->a[i].pExpr;
    if( p==0 ) continue;
    if( pEList->a[i].zName && (realNames == 0 || p->op != TK_COLUMN)){   /*** CHANGED - SQLite.Interop ***/
      char *zName = pEList->a[i].zName;
      sqlite3VdbeSetColName(v, i, zName, strlen(zName));
      continue;
    }
    if( p->op==TK_COLUMN && pTabList ){
      Table *pTab;
      char *zCol;
      int iCol = p->iColumn;
      for(j=0; j<pTabList->nSrc && pTabList->a[j].iCursor!=p->iTable; j++){}
      assert( j<pTabList->nSrc );
      pTab = pTabList->a[j].pTab;
      if( iCol<0 ) iCol = pTab->iPKey;
      assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
      if( iCol<0 ){
        zCol = "rowid";
      }else{
        zCol = pTab->aCol[iCol].zName;
      }
      if( !shortNames && !fullNames && p->span.z && p->span.z[0] ){
        sqlite3VdbeSetColName(v, i, p->span.z, p->span.n);
      }else if( fullNames || (!shortNames && pTabList->nSrc>1) ){
        char *zName = 0;
        char *zTab;
        char *zDb = 0;                                                          /*** ADDED - SQLite.Interop ***/
 
        zTab = pTabList->a[j].zAlias;
        if( fullNames || zTab==0 ){
          if (pTab->iDb > 1) zDb = db->aDb[pTab->iDb].zName;                    /*** ADDED - SQLite.Interop ***/
          zTab = pTab->zName;
        }
        if (!zDb || !realNames) sqlite3SetString(&zName, zTab, ".", zCol, 0);   /*** CHANGED - SQLite.Interop ***/
        else sqlite3SetString(&zName, zDb, ".", zTab, ".", zCol, 0);            /*** ADDED - SQLite.Interop ***/
        sqlite3VdbeSetColName(v, i, zName, P3_DYNAMIC);
      }else{
        sqlite3VdbeSetColName(v, i, zCol, strlen(zCol));
      }
    }else if( p->span.z && p->span.z[0] ){
      sqlite3VdbeSetColName(v, i, p->span.z, p->span.n);
      /* sqlite3VdbeCompressSpace(v, addr); */
    }else{
      char zName[30];
      assert( p->op!=TK_COLUMN || pTabList==0 );
      sprintf(zName, "column%d", i+1);
      sqlite3VdbeSetColName(v, i, zName, 0);
    }
  }
  generateColumnTypes(pParse, pTabList, pEList);
}

#ifdef OS_WIN

typedef void (__stdcall *SQLITEUSERFUNC)(void *, int, void **);
typedef int  (__stdcall *SQLITECOLLATION)(int, const void *, int, const void*);

// Callback wrappers
int sqlite3_interop_collationfunc(void *pv, int len1, const void *pv1, int len2, const void *pv2)
{
  SQLITECOLLATION *p = (SQLITECOLLATION *)pv;
  return p[0](len1, pv1, len2, pv2);
}

void sqlite3_interop_func(sqlite3_context *pctx, int n, sqlite3_value **pv)
{
  SQLITEUSERFUNC *pf = (SQLITEUSERFUNC *)sqlite3_user_data(pctx);
  pf[0](pctx, n, pv);
}

void sqlite3_interop_step(sqlite3_context *pctx, int n, sqlite3_value **pv)
{
  SQLITEUSERFUNC *pf = (SQLITEUSERFUNC *)sqlite3_user_data(pctx);
  pf[1](pctx, n, pv);
}

void sqlite3_interop_final(sqlite3_context *pctx)
{
  SQLITEUSERFUNC *pf = (SQLITEUSERFUNC *)sqlite3_user_data(pctx);
  pf[2](pctx, 0, 0);
}

__declspec(dllexport) void __stdcall sqlite3_function_free_callbackcookie(void *pCookie)
{
  if (pCookie)
    free(pCookie);
}

// sqlite3 wrappers
__declspec(dllexport) const char * __stdcall sqlite3_libversion_interop(int *plen)
{
  const char *val = sqlite3_libversion();
  *plen = (val != 0) ? strlen(val) : 0;

  return val;
}

__declspec(dllexport) int __stdcall sqlite3_libversion_number_interop(void)
{
  return sqlite3_libversion_number();
}

__declspec(dllexport) int __stdcall sqlite3_close_interop(sqlite3 *db)
{
  return sqlite3_close(db);
}

__declspec(dllexport) int __stdcall sqlite3_exec_interop(sqlite3 *db, const char *sql, sqlite3_callback cb, void *pv, char **errmsg, int *plen)
{
  int n = sqlite3_exec(db, sql, cb, pv, errmsg);
  *plen = (*errmsg != 0) ? strlen(*errmsg) : 0;
  return n;
}

__declspec(dllexport) sqlite_int64 __stdcall sqlite3_last_insert_rowid_interop(sqlite3 *db)
{
  return sqlite3_last_insert_rowid(db);
}

__declspec(dllexport) int __stdcall sqlite3_changes_interop(sqlite3 *db)
{
  return sqlite3_changes(db);
}

__declspec(dllexport) int __stdcall sqlite3_total_changes_interop(sqlite3 *db)
{
  return sqlite3_total_changes(db);
}

__declspec(dllexport) void __stdcall sqlite3_interrupt_interop(sqlite3 *db)
{
  sqlite3_interrupt(db);
}

__declspec(dllexport) int __stdcall sqlite3_complete_interop(const char *sql)
{
  return sqlite3_complete(sql);
}

__declspec(dllexport) int __stdcall sqlite3_complete16_interop(const void *sql)
{
  return sqlite3_complete16(sql);
}

__declspec(dllexport) int __stdcall sqlite3_busy_handler_interop(sqlite3 *db, int(*cb)(void *, int), void *pv)
{
  return sqlite3_busy_handler(db, cb, pv);
}

__declspec(dllexport) int __stdcall sqlite3_busy_timeout_interop(sqlite3 *db, int ms)
{
  return sqlite3_busy_timeout(db, ms);
}

__declspec(dllexport) int __stdcall sqlite3_get_table_interop(sqlite3 *db, const char *sql, char ***resultp, int *nrow, int *ncolumn, char **errmsg, int *plen)
{
  int n = sqlite3_get_table(db, sql, resultp, nrow, ncolumn, errmsg);
  *plen = (*errmsg != 0) ? strlen((char *)*errmsg) : 0;
  return n;
}

__declspec(dllexport) void __stdcall sqlite3_free_table_interop(char **result)
{
  sqlite3_free_table(result);
}

__declspec(dllexport) void __stdcall sqlite3_free_interop(char *z)
{
  sqlite3_free(z);
}

__declspec(dllexport) int __stdcall sqlite3_open_interop(const char*filename, sqlite3 **ppdb)
{
  return sqlite3_open(filename, ppdb);
}

__declspec(dllexport) int __stdcall sqlite3_open16_interop(const void *filename, sqlite3 **ppdb)
{
  return sqlite3_open16(filename, ppdb);
}

__declspec(dllexport) int __stdcall sqlite3_errcode_interop(sqlite3 *db)
{
  return sqlite3_errcode(db);
}

__declspec(dllexport) const char * __stdcall sqlite3_errmsg_interop(sqlite3 *db, int *plen)
{
  const char *pval = sqlite3_errmsg(db);
  *plen = (pval != 0) ? strlen(pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_errmsg16_interop(sqlite3 *db)
{
  return sqlite3_errmsg16(db);
}

__declspec(dllexport) int __stdcall sqlite3_prepare_interop(sqlite3 *db, const char *sql, int nbytes, sqlite3_stmt **ppstmt, const char **pztail, int *plen)
{
  int n = sqlite3_prepare(db, sql, nbytes, ppstmt, pztail);
  *plen = (*pztail != 0) ? strlen(*pztail) : 0;
  return n;
}

__declspec(dllexport) int __stdcall sqlite3_prepare16_interop(sqlite3 *db, const void *sql, int nbytes, sqlite3_stmt **ppstmt, const void **pztail)
{
  return sqlite3_prepare16(db, sql, nbytes, ppstmt, pztail);
}

__declspec(dllexport) int __stdcall sqlite3_bind_blob_interop(sqlite3_stmt *stmt, int iCol, const void *pv, int n, void(*cb)(void*))
{
  return sqlite3_bind_blob(stmt, iCol, pv, n, cb);
}

__declspec(dllexport) int __stdcall sqlite3_bind_double_interop(sqlite3_stmt *stmt, int iCol, double *val)
{
	return sqlite3_bind_double(stmt,iCol,*val);
}

__declspec(dllexport) int __stdcall sqlite3_bind_int_interop(sqlite3_stmt *stmt, int iCol, int val)
{
  return sqlite3_bind_int(stmt, iCol, val);
}

__declspec(dllexport) int __stdcall sqlite3_bind_int64_interop(sqlite3_stmt *stmt, int iCol, sqlite_int64 *val)
{
	return sqlite3_bind_int64(stmt,iCol,*val);
}

__declspec(dllexport) int __stdcall sqlite3_bind_null_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_bind_null(stmt, iCol);
}

__declspec(dllexport) int __stdcall sqlite3_bind_text_interop(sqlite3_stmt *stmt, int iCol, const char *val, int n, void(*cb)(void *))
{
  return sqlite3_bind_text(stmt, iCol, val, n, cb);
}

__declspec(dllexport) int __stdcall sqlite3_bind_text16_interop(sqlite3_stmt *stmt, int iCol, const void *val, int n, void(*cb)(void *))
{
  return sqlite3_bind_text16(stmt, iCol, val, n, cb);
}

__declspec(dllexport) int __stdcall sqlite3_bind_parameter_count_interop(sqlite3_stmt *stmt)
{
  return sqlite3_bind_parameter_count(stmt);
}

__declspec(dllexport) const char * __stdcall sqlite3_bind_parameter_name_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  const char *pval = sqlite3_bind_parameter_name(stmt, iCol);
  *plen = (pval != 0) ? strlen(pval) : 0;
  return pval;
}

__declspec(dllexport) int __stdcall sqlite3_bind_parameter_index_interop(sqlite3_stmt *stmt, const char *zName)
{
  return sqlite3_bind_parameter_index(stmt, zName);
}

__declspec(dllexport) int __stdcall sqlite3_column_count_interop(sqlite3_stmt *stmt)
{
  return sqlite3_column_count(stmt);
}

__declspec(dllexport) const char * __stdcall sqlite3_column_name_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  const char *pval = sqlite3_column_name(stmt, iCol);
  *plen = (pval != 0) ? strlen(pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_column_name16_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_column_name16(stmt, iCol);
}

__declspec(dllexport) const char * __stdcall sqlite3_column_decltype_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  const char *pval = sqlite3_column_decltype(stmt, iCol);
  *plen = (pval != 0) ? strlen(pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_column_decltype16_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_column_decltype16(stmt, iCol);
}

__declspec(dllexport) int __stdcall sqlite3_step_interop(sqlite3_stmt *stmt)
{
  return sqlite3_step(stmt);
}

__declspec(dllexport) int __stdcall sqlite3_data_count_interop(sqlite3_stmt *stmt)
{
  return sqlite3_data_count(stmt);
}

__declspec(dllexport) const void * __stdcall sqlite3_column_blob_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_column_blob(stmt, iCol);
}

__declspec(dllexport) int __stdcall sqlite3_column_bytes_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_column_bytes(stmt, iCol);
}

__declspec(dllexport) int __stdcall sqlite3_column_bytes16_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_column_bytes16(stmt, iCol);
}

__declspec(dllexport) void __stdcall sqlite3_column_double_interop(sqlite3_stmt *stmt, int iCol, double *val)
{
	*val = sqlite3_column_double(stmt,iCol);
}

__declspec(dllexport) int __stdcall sqlite3_column_int_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_column_int(stmt, iCol);
}

__declspec(dllexport) void __stdcall sqlite3_column_int64_interop(sqlite3_stmt *stmt, int iCol, sqlite_int64 *val)
{
	*val = sqlite3_column_int64(stmt,iCol);
}

__declspec(dllexport) const unsigned char * __stdcall sqlite3_column_text_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  const unsigned char *pval = sqlite3_column_text(stmt, iCol);
  *plen = (pval != 0) ? strlen(pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_column_text16_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_column_text16(stmt, iCol);
}

__declspec(dllexport) int __stdcall sqlite3_column_type_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_column_type(stmt, iCol);
}

__declspec(dllexport) int __stdcall sqlite3_finalize_interop(sqlite3_stmt *stmt)
{
  return sqlite3_finalize(stmt);
}

__declspec(dllexport) int __stdcall sqlite3_reset_interop(sqlite3_stmt *stmt)
{
  return sqlite3_reset(stmt);
}

__declspec(dllexport) int __stdcall sqlite3_create_function_interop(sqlite3 *psql, const char *zFunctionName, int nArg, int eTextRep, SQLITEUSERFUNC func, SQLITEUSERFUNC funcstep, SQLITEUSERFUNC funcfinal, void **ppCookie)
{
  int n;
  SQLITEUSERFUNC *p = malloc(sizeof(SQLITEUSERFUNC) * 3);

  p[0] = func;
  p[1] = funcstep;
  p[2] = funcfinal;

  *ppCookie = 0;

  n = sqlite3_create_function(psql, zFunctionName, nArg, eTextRep, p, (func != 0) ? sqlite3_interop_func : 0, (funcstep != 0) ? sqlite3_interop_step : 0, (funcfinal != 0) ? sqlite3_interop_final : 0);
  if (n != 0)
    free(p);
  else
    *ppCookie = p;

  return n;
}

__declspec(dllexport) int __stdcall sqlite3_create_function16_interop(sqlite3 *psql, void *zFunctionName, int nArg, int eTextRep, SQLITEUSERFUNC func, SQLITEUSERFUNC funcstep, SQLITEUSERFUNC funcfinal, void **ppCookie)
{
  int n;
  SQLITEUSERFUNC *p = malloc(sizeof(SQLITEUSERFUNC) * 3);

  p[0] = func;
  p[1] = funcstep;
  p[2] = funcfinal;

  *ppCookie = 0;

  n = sqlite3_create_function16(psql, zFunctionName, nArg, eTextRep, p, (func != 0) ? sqlite3_interop_func : 0, (funcstep != 0) ? sqlite3_interop_step : 0, (funcfinal != 0) ? sqlite3_interop_final : 0);
  if (n != 0)
    free(p);
  else
    *ppCookie = p;

  return n;
}

__declspec(dllexport) int __stdcall sqlite3_create_collation_interop(sqlite3* db, const char *zName, int eTextRep, void* pvUser, SQLITECOLLATION func, void **ppCookie)
{
  int n;
  SQLITECOLLATION *p = malloc(sizeof(SQLITECOLLATION));
  
  p[0] = func;

  *ppCookie = 0;

  n = sqlite3_create_collation(db, zName, eTextRep, p, sqlite3_interop_collationfunc);
  if (n != 0)
    free(p);
  else
    *ppCookie = p;

  return n;
}

__declspec(dllexport) int __stdcall sqlite3_create_collation16_interop(sqlite3* db, const void *zName, int eTextRep, void* pvUser, SQLITECOLLATION func, void **ppCookie)
{
  int n;
  SQLITECOLLATION *p = malloc(sizeof(SQLITECOLLATION));
  
  p[0] = func;

  *ppCookie = 0;

  n = sqlite3_create_collation16(db, (const char *)zName, eTextRep, p, sqlite3_interop_collationfunc);
  if (n != 0)
    free(p);
  else
    *ppCookie = p;

  return n;
}

__declspec(dllexport) int __stdcall sqlite3_aggregate_count_interop(sqlite3_context *pctx)
{
  return sqlite3_aggregate_count(pctx);
}

__declspec(dllexport) const void * __stdcall sqlite3_value_blob_interop(sqlite3_value *val)
{
  return sqlite3_value_blob(val);
}

__declspec(dllexport) int __stdcall sqlite3_value_bytes_interop(sqlite3_value *val)
{
  return sqlite3_value_bytes(val);
}

__declspec(dllexport) int __stdcall sqlite3_value_bytes16_interop(sqlite3_value *val)
{
  return sqlite3_value_bytes16(val);
}

__declspec(dllexport) void __stdcall sqlite3_value_double_interop(sqlite3_value *pval, double *val)
{
  *val = sqlite3_value_double(pval);
}

__declspec(dllexport) int __stdcall sqlite3_value_int_interop(sqlite3_value *val)
{
  return sqlite3_value_int(val);
}

__declspec(dllexport) void __stdcall sqlite3_value_int64_interop(sqlite3_value *pval, sqlite_int64 *val)
{
  *val = sqlite3_value_int64(pval);
}

__declspec(dllexport) const unsigned char * __stdcall sqlite3_value_text_interop(sqlite3_value *val, int *plen)
{
  const unsigned char *pval = sqlite3_value_text(val);
  *plen = (pval != 0) ? strlen(pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_value_text16_interop(sqlite3_value *val)
{
  return sqlite3_value_text16(val);
}

__declspec(dllexport) int __stdcall sqlite3_value_type_interop(sqlite3_value *val)
{
  return sqlite3_value_type(val);
}

__declspec(dllexport) void * __stdcall sqlite3_aggregate_context_interop(sqlite3_context *pctx, int n)
{
  return sqlite3_aggregate_context(pctx, n);
}

__declspec(dllexport) void __stdcall sqlite3_result_blob_interop(sqlite3_context *ctx, const void *pv, int n, void(*cb)(void *))
{
  sqlite3_result_blob(ctx, pv, n, cb);
}

__declspec(dllexport) void __stdcall sqlite3_result_double_interop(sqlite3_context *pctx, double *val)
{
  sqlite3_result_double(pctx, *val);
}

__declspec(dllexport) void __stdcall sqlite3_result_int_interop(sqlite3_context *pctx, int val)
{
  sqlite3_result_int(pctx, val);
}

__declspec(dllexport) void __stdcall sqlite3_result_int64_interop(sqlite3_context *pctx, sqlite_int64 *val)
{
  sqlite3_result_int64(pctx, *val);
}

__declspec(dllexport) void __stdcall sqlite3_result_null_interop(sqlite3_context *pctx)
{
  sqlite3_result_null(pctx);
}

__declspec(dllexport) void __stdcall sqlite3_result_error_interop(sqlite3_context *ctx, const char *pv, int n)
{
  sqlite3_result_error(ctx, pv, n);
}

__declspec(dllexport) void __stdcall sqlite3_result_error16_interop(sqlite3_context *ctx, const void *pv, int n)
{
  sqlite3_result_error16(ctx, pv, n);
}

__declspec(dllexport) void __stdcall sqlite3_result_text_interop(sqlite3_context *ctx, const char *pv, int n, void(*cb)(void *))
{
  sqlite3_result_text(ctx, pv, n, cb);
}

__declspec(dllexport) void __stdcall sqlite3_result_text16_interop(sqlite3_context *ctx, const void *pv, int n, void(*cb)(void *))
{
  sqlite3_result_text16(ctx, pv, n, cb);
}

__declspec(dllexport) void __stdcall sqlite3_realcolnames(sqlite3 *db, int bOn)
{
  if (bOn)
    db->flags |= 0x01000000;
  else
    db->flags &= (~0x01000000);
}

#endif // OS_WIN

Added SQLite.Interop/src/alter.c.





























































































































































































































































































































































































































































































































































































































































































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/*
** 2005 February 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 file contains C code routines that used to generate VDBE code
** that implements the ALTER TABLE command.
**
** $Id: alter.c,v 1.1 2005/03/01 16:04:26 rmsimpson Exp $
*/
#include "sqliteInt.h"

/*
** The code in this file only exists if we are not omitting the
** ALTER TABLE logic from the build.
*/
#ifndef SQLITE_OMIT_ALTERTABLE


/*
** This function is used by SQL generated to implement the 
** ALTER TABLE command. The first argument is the text of a CREATE TABLE or
** CREATE INDEX command. The second is a table name. The table name in 
** the CREATE TABLE or CREATE INDEX statement is replaced with the second
** argument and the result returned. Examples:
**
** sqlite_rename_table('CREATE TABLE abc(a, b, c)', 'def')
**     -> 'CREATE TABLE def(a, b, c)'
**
** sqlite_rename_table('CREATE INDEX i ON abc(a)', 'def')
**     -> 'CREATE INDEX i ON def(a, b, c)'
*/
static void renameTableFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  unsigned char const *zSql = sqlite3_value_text(argv[0]);
  unsigned char const *zTableName = sqlite3_value_text(argv[1]);

  int token;
  Token tname;
  char const *zCsr = zSql;
  int len = 0;
  char *zRet;

  /* The principle used to locate the table name in the CREATE TABLE 
  ** statement is that the table name is the first token that is immediatedly
  ** followed by a left parenthesis - TK_LP.
  */
  if( zSql ){
    do {
      /* Store the token that zCsr points to in tname. */
      tname.z = zCsr;
      tname.n = len;

      /* Advance zCsr to the next token. Store that token type in 'token',
      ** and it's length in 'len' (to be used next iteration of this loop).
      */
      do {
        zCsr += len;
        len = sqlite3GetToken(zCsr, &token);
      } while( token==TK_SPACE );
      assert( len>0 );
    } while( token!=TK_LP );

    zRet = sqlite3MPrintf("%.*s%Q%s", tname.z - zSql, zSql, 
       zTableName, tname.z+tname.n);
    sqlite3_result_text(context, zRet, -1, sqlite3FreeX);
  }
}

#ifndef SQLITE_OMIT_TRIGGER
/* This function is used by SQL generated to implement the ALTER TABLE
** ALTER TABLE command. The first argument is the text of a CREATE TRIGGER 
** statement. The second is a table name. The table name in the CREATE 
** TRIGGER statement is replaced with the second argument and the result 
** returned. This is analagous to renameTableFunc() above, except for CREATE
** TRIGGER, not CREATE INDEX and CREATE TABLE.
*/
static void renameTriggerFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  unsigned char const *zSql = sqlite3_value_text(argv[0]);
  unsigned char const *zTableName = sqlite3_value_text(argv[1]);

  int token;
  Token tname;
  int dist = 3;
  char const *zCsr = zSql;
  int len = 0;
  char *zRet;

  /* The principle used to locate the table name in the CREATE TRIGGER 
  ** statement is that the table name is the first token that is immediatedly
  ** preceded by either TK_ON or TK_DOT and immediatedly followed by one
  ** of TK_WHEN, TK_BEGIN or TK_FOR.
  */
  if( zSql ){
    do {
      /* Store the token that zCsr points to in tname. */
      tname.z = zCsr;
      tname.n = len;

      /* Advance zCsr to the next token. Store that token type in 'token',
      ** and it's length in 'len' (to be used next iteration of this loop).
      */
      do {
        zCsr += len;
        len = sqlite3GetToken(zCsr, &token);
      }while( token==TK_SPACE );
      assert( len>0 );

      /* Variable 'dist' stores the number of tokens read since the most
      ** recent TK_DOT or TK_ON. This means that when a WHEN, FOR or BEGIN 
      ** token is read and 'dist' equals 2, the condition stated above
      ** to be met.
      **
      ** Note that ON cannot be a database, table or column name, so
      ** there is no need to worry about syntax like 
      ** "CREATE TRIGGER ... ON ON.ON BEGIN ..." etc.
      */
      dist++;
      if( token==TK_DOT || token==TK_ON ){
        dist = 0;
      }
    } while( dist!=2 || (token!=TK_WHEN && token!=TK_FOR && token!=TK_BEGIN) );

    /* Variable tname now contains the token that is the old table-name
    ** in the CREATE TRIGGER statement.
    */
    zRet = sqlite3MPrintf("%.*s%Q%s", tname.z - zSql, zSql, 
       zTableName, tname.z+tname.n);
    sqlite3_result_text(context, zRet, -1, sqlite3FreeX);
  }
}
#endif   /* !SQLITE_OMIT_TRIGGER */

/*
** Register built-in functions used to help implement ALTER TABLE
*/
void sqlite3AlterFunctions(sqlite3 *db){
  static const struct {
     char *zName;
     signed char nArg;
     void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
  } aFuncs[] = {
    { "sqlite_rename_table",    2, renameTableFunc},
#ifndef SQLITE_OMIT_TRIGGER
    { "sqlite_rename_trigger",  2, renameTriggerFunc},
#endif
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
        SQLITE_UTF8, 0, aFuncs[i].xFunc, 0, 0);
  }
}

/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy" 
** command. 
*/
void sqlite3AlterRenameTable(
  Parse *pParse,            /* Parser context. */
  SrcList *pSrc,            /* The table to rename. */
  Token *pName              /* The new table name. */
){
  int iDb;                  /* Database that contains the table */
  char *zDb;                /* Name of database iDb */
  Table *pTab;              /* Table being renamed */
  char *zName = 0;          /* NULL-terminated version of pName */ 
  char *zWhere = 0;         /* Where clause of schema elements to reparse */
  sqlite3 *db = pParse->db; /* Database connection */
  Vdbe *v;
#ifndef SQLITE_OMIT_TRIGGER
  char *zTempTrig = 0;      /* Where clause to locate temp triggers */
#endif
  
  assert( pSrc->nSrc==1 );

  pTab = sqlite3LocateTable(pParse, pSrc->a[0].zName, pSrc->a[0].zDatabase);
  if( !pTab ) goto exit_rename_table;
  iDb = pTab->iDb;
  zDb = db->aDb[iDb].zName;

  /* Get a NULL terminated version of the new table name. */
  zName = sqlite3NameFromToken(pName);
  if( !zName ) goto exit_rename_table;

  /* Check that a table or index named 'zName' does not already exist
  ** in database iDb. If so, this is an error.
  */
  if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
    sqlite3ErrorMsg(pParse, 
        "there is already another table or index with this name: %s", zName);
    goto exit_rename_table;
  }

  /* Make sure it is not a system table being altered, or a reserved name
  ** that the table is being renamed to.
  */
  if( strlen(pTab->zName)>6 && 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7) ){
    sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);
    goto exit_rename_table;
  }
  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
    goto exit_rename_table;
  }

#ifndef SQLITE_OMIT_AUTHORIZATION
  /* Invoke the authorization callback. */
  if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
    goto exit_rename_table;
  }
#endif

  /* Begin a transaction and code the VerifyCookie for database iDb. 
  ** Then modify the schema cookie (since the ALTER TABLE modifies the
  ** schema).
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ){
    goto exit_rename_table;
  }
  sqlite3BeginWriteOperation(pParse, 0, iDb);
  sqlite3ChangeCookie(db, v, iDb);

  /* Modify the sqlite_master table to use the new table name. */
  sqlite3NestedParse(pParse,
      "UPDATE %Q.%s SET "
#ifdef SQLITE_OMIT_TRIGGER
          "sql = sqlite_rename_table(sql, %Q), "
#else
          "sql = CASE "
            "WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
            "ELSE sqlite_rename_table(sql, %Q) END, "
#endif
          "tbl_name = %Q, "
          "name = CASE "
            "WHEN type='table' THEN %Q "
            "WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
              "'sqlite_autoindex_' || %Q || substr(name, %d+18,10) "
            "ELSE name END "
      "WHERE tbl_name=%Q AND "
          "(type='table' OR type='index' OR type='trigger');", 
      zDb, SCHEMA_TABLE(iDb), zName, zName, zName, 
#ifndef SQLITE_OMIT_TRIGGER
zName,
#endif
      zName, strlen(pTab->zName), pTab->zName
  );

#ifndef SQLITE_OMIT_AUTOINCREMENT
  /* If the sqlite_sequence table exists in this database, then update 
  ** it with the new table name.
  */
  if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
    sqlite3NestedParse(pParse,
        "UPDATE %Q.sqlite_sequence set name = %Q WHERE name = %Q",
        zDb, zName, pTab->zName);
  }
#endif

#ifndef SQLITE_OMIT_TRIGGER
  /* If there are TEMP triggers on this table, modify the sqlite_temp_master
  ** table. Don't do this if the table being ALTERed is itself located in
  ** the temp database.
  */
  if( iDb!=1 ){
    Trigger *pTrig;
    char *tmp = 0;
    for( pTrig=pTab->pTrigger; pTrig; pTrig=pTrig->pNext ){
      if( pTrig->iDb==1 ){
        if( !zTempTrig ){
          zTempTrig = 
              sqlite3MPrintf("type = 'trigger' AND (name=%Q", pTrig->name);
        }else{
          tmp = zTempTrig;
          zTempTrig = sqlite3MPrintf("%s OR name=%Q", zTempTrig, pTrig->name);
          sqliteFree(tmp);
        }
      }
    }
    if( zTempTrig ){
      tmp = zTempTrig;
      zTempTrig = sqlite3MPrintf("%s)", zTempTrig);
      sqliteFree(tmp);
      sqlite3NestedParse(pParse, 
          "UPDATE sqlite_temp_master SET "
              "sql = sqlite_rename_trigger(sql, %Q), "
              "tbl_name = %Q "
              "WHERE %s;", zName, zName, zTempTrig);
    }
  }
#endif

  /* Drop the elements of the in-memory schema that refered to the table
  ** renamed and load the new versions from the database.
  */
  if( pParse->nErr==0 ){
#ifndef SQLITE_OMIT_TRIGGER
    Trigger *pTrig;
    for( pTrig=pTab->pTrigger; pTrig; pTrig=pTrig->pNext ){
      assert( pTrig->iDb==iDb || pTrig->iDb==1 );
      sqlite3VdbeOp3(v, OP_DropTrigger, pTrig->iDb, 0, pTrig->name, 0);
    }
#endif
    sqlite3VdbeOp3(v, OP_DropTable, iDb, 0, pTab->zName, 0);
    zWhere = sqlite3MPrintf("tbl_name=%Q", zName);
    sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0, zWhere, P3_DYNAMIC);
#ifndef SQLITE_OMIT_TRIGGER
    if( zTempTrig ){
      sqlite3VdbeOp3(v, OP_ParseSchema, 1, 0, zTempTrig, P3_DYNAMIC);
    }
  }else{
    sqliteFree(zTempTrig);
#endif
  }

exit_rename_table:
  sqlite3SrcListDelete(pSrc);
  sqliteFree(zName);
}
#endif  /* SQLITE_ALTER_TABLE */

Added SQLite.Interop/src/attach.c.





































































































































































































































































































































































































































































































































































































































































































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/*
** 2003 April 6
**
** 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 code used to implement the ATTACH and DETACH commands.
**
** $Id: attach.c,v 1.1 2005/03/01 16:04:26 rmsimpson Exp $
*/
#include "sqliteInt.h"

/*
** This routine is called by the parser to process an ATTACH statement:
**
**     ATTACH DATABASE filename AS dbname
**
** The pFilename and pDbname arguments are the tokens that define the
** filename and dbname in the ATTACH statement.
*/
void sqlite3Attach(
  Parse *pParse,       /* The parser context */
  Token *pFilename,    /* Name of database file */
  Token *pDbname,      /* Name of the database to use internally */
  int keyType,         /* 0: no key.  1: TEXT,  2: BLOB */
  Token *pKey          /* Text of the key for keytype 1 and 2 */
){
  Db *aNew;
  int rc, i;
  char *zFile, *zName;
  sqlite3 *db;
  Vdbe *v;

  v = sqlite3GetVdbe(pParse);
  if( !v ) return;
  sqlite3VdbeAddOp(v, OP_Expire, 1, 0);
  sqlite3VdbeAddOp(v, OP_Halt, 0, 0);
  if( pParse->explain ) return;
  db = pParse->db;
  if( db->nDb>=MAX_ATTACHED+2 ){
    sqlite3ErrorMsg(pParse, "too many attached databases - max %d", 
       MAX_ATTACHED);
    pParse->rc = SQLITE_ERROR;
    return;
  }

  if( !db->autoCommit ){
    sqlite3ErrorMsg(pParse, "cannot ATTACH database within transaction");
    pParse->rc = SQLITE_ERROR;
    return;
  }

  zFile = sqlite3NameFromToken(pFilename);;
  if( zFile==0 ) return;
#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse, SQLITE_ATTACH, zFile, 0, 0)!=SQLITE_OK ){
    sqliteFree(zFile);
    return;
  }
#endif /* SQLITE_OMIT_AUTHORIZATION */

  zName = sqlite3NameFromToken(pDbname);
  if( zName==0 ) return;
  for(i=0; i<db->nDb; i++){
    char *z = db->aDb[i].zName;
    if( z && sqlite3StrICmp(z, zName)==0 ){
      sqlite3ErrorMsg(pParse, "database %z is already in use", zName);
      pParse->rc = SQLITE_ERROR;
      sqliteFree(zFile);
      return;
    }
  }

  if( db->aDb==db->aDbStatic ){
    aNew = sqliteMalloc( sizeof(db->aDb[0])*3 );
    if( aNew==0 ) return;
    memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
  }else{
    aNew = sqliteRealloc(db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
    if( aNew==0 ) return;
  }
  db->aDb = aNew;
  aNew = &db->aDb[db->nDb++];
  memset(aNew, 0, sizeof(*aNew));
  sqlite3HashInit(&aNew->tblHash, SQLITE_HASH_STRING, 0);
  sqlite3HashInit(&aNew->idxHash, SQLITE_HASH_STRING, 0);
  sqlite3HashInit(&aNew->trigHash, SQLITE_HASH_STRING, 0);
  sqlite3HashInit(&aNew->aFKey, SQLITE_HASH_STRING, 1);
  aNew->zName = zName;
  aNew->safety_level = 3;
  rc = sqlite3BtreeFactory(db, zFile, 0, MAX_PAGES, &aNew->pBt);
  if( rc ){
    sqlite3ErrorMsg(pParse, "unable to open database: %s", zFile);
  }
#if SQLITE_HAS_CODEC
  {
    extern int sqlite3CodecAttach(sqlite3*, int, void*, int);
    char *zKey;
    int nKey;
    if( keyType==0 ){
      /* No key specified.  Use the key from the main database */
      extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
      sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
    }else if( keyType==1 ){
      /* Key specified as text */
      zKey = sqlite3NameFromToken(pKey);
      nKey = strlen(zKey);
    }else{
      /* Key specified as a BLOB */
      char *zTemp;
      assert( keyType==2 );
      pKey->z++;
      pKey->n--;
      zTemp = sqlite3NameFromToken(pKey);
      zKey = sqlite3HexToBlob(zTemp);
      sqliteFree(zTemp);
    }
    sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
    if( keyType ){
      sqliteFree(zKey);
    }
  }
#endif
  sqliteFree(zFile);
  db->flags &= ~SQLITE_Initialized;
  if( pParse->nErr==0 && rc==SQLITE_OK ){
    rc = sqlite3ReadSchema(pParse);
  }
  if( rc ){
    int i = db->nDb - 1;
    assert( i>=2 );
    if( db->aDb[i].pBt ){
      sqlite3BtreeClose(db->aDb[i].pBt);
      db->aDb[i].pBt = 0;
    }
    sqlite3ResetInternalSchema(db, 0);
    if( 0==pParse->nErr ){
      pParse->nErr++;
      pParse->rc = SQLITE_ERROR;
    }
  }
}

/*
** This routine is called by the parser to process a DETACH statement:
**
**    DETACH DATABASE dbname
**
** The pDbname argument is the name of the database in the DETACH statement.
*/
void sqlite3Detach(Parse *pParse, Token *pDbname){
  int i;
  sqlite3 *db;
  Vdbe *v;
  Db *pDb = 0;

  v = sqlite3GetVdbe(pParse);
  if( !v ) return;
  sqlite3VdbeAddOp(v, OP_Expire, 0, 0);
  sqlite3VdbeAddOp(v, OP_Halt, 0, 0);
  if( pParse->explain ) return;
  db = pParse->db;
  for(i=0; i<db->nDb; i++){
    pDb = &db->aDb[i];
    if( pDb->pBt==0 || pDb->zName==0 ) continue;
    if( strlen(pDb->zName)!=pDbname->n ) continue;
    if( sqlite3StrNICmp(pDb->zName, pDbname->z, pDbname->n)==0 ) break;
  }
  if( i>=db->nDb ){
    sqlite3ErrorMsg(pParse, "no such database: %T", pDbname);
    return;
  }
  if( i<2 ){
    sqlite3ErrorMsg(pParse, "cannot detach database %T", pDbname);
    return;
  }
  if( !db->autoCommit ){
    sqlite3ErrorMsg(pParse, "cannot DETACH database within transaction");
    pParse->rc = SQLITE_ERROR;
    return;
  }
#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse,SQLITE_DETACH,db->aDb[i].zName,0,0)!=SQLITE_OK ){
    return;
  }
#endif /* SQLITE_OMIT_AUTHORIZATION */
  sqlite3BtreeClose(pDb->pBt);
  pDb->pBt = 0;
  sqlite3ResetInternalSchema(db, 0);
}

/*
** Initialize a DbFixer structure.  This routine must be called prior
** to passing the structure to one of the sqliteFixAAAA() routines below.
**
** The return value indicates whether or not fixation is required.  TRUE
** means we do need to fix the database references, FALSE means we do not.
*/
int sqlite3FixInit(
  DbFixer *pFix,      /* The fixer to be initialized */
  Parse *pParse,      /* Error messages will be written here */
  int iDb,            /* This is the database that must be used */
  const char *zType,  /* "view", "trigger", or "index" */
  const Token *pName  /* Name of the view, trigger, or index */
){
  sqlite3 *db;

  if( iDb<0 || iDb==1 ) return 0;
  db = pParse->db;
  assert( db->nDb>iDb );
  pFix->pParse = pParse;
  pFix->zDb = db->aDb[iDb].zName;
  pFix->zType = zType;
  pFix->pName = pName;
  return 1;
}

/*
** The following set of routines walk through the parse tree and assign
** a specific database to all table references where the database name
** was left unspecified in the original SQL statement.  The pFix structure
** must have been initialized by a prior call to sqlite3FixInit().
**
** These routines are used to make sure that an index, trigger, or
** view in one database does not refer to objects in a different database.
** (Exception: indices, triggers, and views in the TEMP database are
** allowed to refer to anything.)  If a reference is explicitly made
** to an object in a different database, an error message is added to
** pParse->zErrMsg and these routines return non-zero.  If everything
** checks out, these routines return 0.
*/
int sqlite3FixSrcList(
  DbFixer *pFix,       /* Context of the fixation */
  SrcList *pList       /* The Source list to check and modify */
){
  int i;
  const char *zDb;
  struct SrcList_item *pItem;

  if( pList==0 ) return 0;
  zDb = pFix->zDb;
  for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
    if( pItem->zDatabase==0 ){
      pItem->zDatabase = sqliteStrDup(zDb);
    }else if( sqlite3StrICmp(pItem->zDatabase,zDb)!=0 ){
      sqlite3ErrorMsg(pFix->pParse,
         "%s %T cannot reference objects in database %s",
         pFix->zType, pFix->pName, pItem->zDatabase);
      return 1;
    }
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
    if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1;
    if( sqlite3FixExpr(pFix, pItem->pOn) ) return 1;
#endif
  }
  return 0;
}
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
int sqlite3FixSelect(
  DbFixer *pFix,       /* Context of the fixation */
  Select *pSelect      /* The SELECT statement to be fixed to one database */
){
  while( pSelect ){
    if( sqlite3FixExprList(pFix, pSelect->pEList) ){
      return 1;
    }
    if( sqlite3FixSrcList(pFix, pSelect->pSrc) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pSelect->pWhere) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pSelect->pHaving) ){
      return 1;
    }
    pSelect = pSelect->pPrior;
  }
  return 0;
}
int sqlite3FixExpr(
  DbFixer *pFix,     /* Context of the fixation */
  Expr *pExpr        /* The expression to be fixed to one database */
){
  while( pExpr ){
    if( sqlite3FixSelect(pFix, pExpr->pSelect) ){
      return 1;
    }
    if( sqlite3FixExprList(pFix, pExpr->pList) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pExpr->pRight) ){
      return 1;
    }
    pExpr = pExpr->pLeft;
  }
  return 0;
}
int sqlite3FixExprList(
  DbFixer *pFix,     /* Context of the fixation */
  ExprList *pList    /* The expression to be fixed to one database */
){
  int i;
  struct ExprList_item *pItem;
  if( pList==0 ) return 0;
  for(i=0, pItem=pList->a; i<pList->nExpr; i++, pItem++){
    if( sqlite3FixExpr(pFix, pItem->pExpr) ){
      return 1;
    }
  }
  return 0;
}
#endif

#ifndef SQLITE_OMIT_TRIGGER
int sqlite3FixTriggerStep(
  DbFixer *pFix,     /* Context of the fixation */
  TriggerStep *pStep /* The trigger step be fixed to one database */
){
  while( pStep ){
    if( sqlite3FixSelect(pFix, pStep->pSelect) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pStep->pWhere) ){
      return 1;
    }
    if( sqlite3FixExprList(pFix, pStep->pExprList) ){
      return 1;
    }
    pStep = pStep->pNext;
  }
  return 0;
}
#endif

Added SQLite.Interop/src/auth.c.

































































































































































































































































































































































































































































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/*
** 2003 January 11
**
** 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 code used to implement the sqlite3_set_authorizer()
** API.  This facility is an optional feature of the library.  Embedded
** systems that do not need this facility may omit it by recompiling
** the library with -DSQLITE_OMIT_AUTHORIZATION=1
**
** $Id: auth.c,v 1.1 2005/03/01 16:04:26 rmsimpson Exp $
*/
#include "sqliteInt.h"

/*
** All of the code in this file may be omitted by defining a single
** macro.
*/
#ifndef SQLITE_OMIT_AUTHORIZATION

/*
** Set or clear the access authorization function.
**
** The access authorization function is be called during the compilation
** phase to verify that the user has read and/or write access permission on
** various fields of the database.  The first argument to the auth function
** is a copy of the 3rd argument to this routine.  The second argument
** to the auth function is one of these constants:
**
**       SQLITE_CREATE_INDEX
**       SQLITE_CREATE_TABLE
**       SQLITE_CREATE_TEMP_INDEX
**       SQLITE_CREATE_TEMP_TABLE
**       SQLITE_CREATE_TEMP_TRIGGER
**       SQLITE_CREATE_TEMP_VIEW
**       SQLITE_CREATE_TRIGGER
**       SQLITE_CREATE_VIEW
**       SQLITE_DELETE
**       SQLITE_DROP_INDEX
**       SQLITE_DROP_TABLE
**       SQLITE_DROP_TEMP_INDEX
**       SQLITE_DROP_TEMP_TABLE
**       SQLITE_DROP_TEMP_TRIGGER
**       SQLITE_DROP_TEMP_VIEW
**       SQLITE_DROP_TRIGGER
**       SQLITE_DROP_VIEW
**       SQLITE_INSERT
**       SQLITE_PRAGMA
**       SQLITE_READ
**       SQLITE_SELECT
**       SQLITE_TRANSACTION
**       SQLITE_UPDATE
**
** The third and fourth arguments to the auth function are the name of
** the table and the column that are being accessed.  The auth function
** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE.  If
** SQLITE_OK is returned, it means that access is allowed.  SQLITE_DENY
** means that the SQL statement will never-run - the sqlite3_exec() call
** will return with an error.  SQLITE_IGNORE means that the SQL statement
** should run but attempts to read the specified column will return NULL
** and attempts to write the column will be ignored.
**
** Setting the auth function to NULL disables this hook.  The default
** setting of the auth function is NULL.
*/
int sqlite3_set_authorizer(
  sqlite3 *db,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pArg
){
  db->xAuth = xAuth;
  db->pAuthArg = pArg;
  sqlite3ExpirePreparedStatements(db);
  return SQLITE_OK;
}

/*
** Write an error message into pParse->zErrMsg that explains that the
** user-supplied authorization function returned an illegal value.
*/
static void sqliteAuthBadReturnCode(Parse *pParse, int rc){
  sqlite3ErrorMsg(pParse, "illegal return value (%d) from the "
    "authorization function - should be SQLITE_OK, SQLITE_IGNORE, "
    "or SQLITE_DENY", rc);
  pParse->rc = SQLITE_ERROR;
}

/*
** The pExpr should be a TK_COLUMN expression.  The table referred to
** is in pTabList or else it is the NEW or OLD table of a trigger.  
** Check to see if it is OK to read this particular column.
**
** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 
** instruction into a TK_NULL.  If the auth function returns SQLITE_DENY,
** then generate an error.
*/
void sqlite3AuthRead(
  Parse *pParse,        /* The parser context */
  Expr *pExpr,          /* The expression to check authorization on */
  SrcList *pTabList     /* All table that pExpr might refer to */
){
  sqlite3 *db = pParse->db;
  int rc;
  Table *pTab;          /* The table being read */
  const char *zCol;     /* Name of the column of the table */
  int iSrc;             /* Index in pTabList->a[] of table being read */
  const char *zDBase;   /* Name of database being accessed */
  TriggerStack *pStack; /* The stack of current triggers */

  if( db->xAuth==0 ) return;
  assert( pExpr->op==TK_COLUMN );
  for(iSrc=0; pTabList && iSrc<pTabList->nSrc; iSrc++){
    if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
  }
  if( iSrc>=0 && pTabList && iSrc<pTabList->nSrc ){
    pTab = pTabList->a[iSrc].pTab;
  }else if( (pStack = pParse->trigStack)!=0 ){
    /* This must be an attempt to read the NEW or OLD pseudo-tables
    ** of a trigger.
    */
    assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx );
    pTab = pStack->pTab;
  }else{
    return;
  }
  if( pTab==0 ) return;
  if( pExpr->iColumn>=0 ){
    assert( pExpr->iColumn<pTab->nCol );
    zCol = pTab->aCol[pExpr->iColumn].zName;
  }else if( pTab->iPKey>=0 ){
    assert( pTab->iPKey<pTab->nCol );
    zCol = pTab->aCol[pTab->iPKey].zName;
  }else{
    zCol = "ROWID";
  }
  assert( pExpr->iDb<db->nDb );
  zDBase = db->aDb[pExpr->iDb].zName;
  rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase, 
                 pParse->zAuthContext);
  if( rc==SQLITE_IGNORE ){
    pExpr->op = TK_NULL;
  }else if( rc==SQLITE_DENY ){
    if( db->nDb>2 || pExpr->iDb!=0 ){
      sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited", 
         zDBase, pTab->zName, zCol);
    }else{
      sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited",pTab->zName,zCol);
    }
    pParse->rc = SQLITE_AUTH;
  }else if( rc!=SQLITE_OK ){
    sqliteAuthBadReturnCode(pParse, rc);
  }
}

/*
** Do an authorization check using the code and arguments given.  Return
** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY.  If SQLITE_DENY
** is returned, then the error count and error message in pParse are
** modified appropriately.
*/
int sqlite3AuthCheck(
  Parse *pParse,
  int code,
  const char *zArg1,
  const char *zArg2,
  const char *zArg3
){
  sqlite3 *db = pParse->db;
  int rc;

  /* Don't do any authorization checks if the database is initialising. */
  if( db->init.busy ){
    return SQLITE_OK;
  }

  if( db->xAuth==0 ){
    return SQLITE_OK;
  }
  rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
  if( rc==SQLITE_DENY ){
    sqlite3ErrorMsg(pParse, "not authorized");
    pParse->rc = SQLITE_AUTH;
  }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
    rc = SQLITE_DENY;
    sqliteAuthBadReturnCode(pParse, rc);
  }
  return rc;
}

/*
** Push an authorization context.  After this routine is called, the
** zArg3 argument to authorization callbacks will be zContext until
** popped.  Or if pParse==0, this routine is a no-op.
*/
void sqlite3AuthContextPush(
  Parse *pParse,
  AuthContext *pContext, 
  const char *zContext
){
  pContext->pParse = pParse;
  if( pParse ){
    pContext->zAuthContext = pParse->zAuthContext;
    pParse->zAuthContext = zContext;
  }
}

/*
** Pop an authorization context that was previously pushed
** by sqlite3AuthContextPush
*/
void sqlite3AuthContextPop(AuthContext *pContext){
  if( pContext->pParse ){
    pContext->pParse->zAuthContext = pContext->zAuthContext;
    pContext->pParse = 0;
  }
}

#endif /* SQLITE_OMIT_AUTHORIZATION */

Added SQLite.Interop/src/btree.c.












































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































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/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.1 2005/03/01 16:04:27 rmsimpson Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
**
** The basic idea is that each page of the file contains N database
** entries and N+1 pointers to subpages.
**
**   ----------------------------------------------------------------
**   |  Ptr(0) | Key(0) | Ptr(1) | Key(1) | ... | Key(N) | Ptr(N+1) |
**   ----------------------------------------------------------------
**
** All of the keys on the page that Ptr(0) points to have values less
** than Key(0).  All of the keys on page Ptr(1) and its subpages have
** values greater than Key(0) and less than Key(1).  All of the keys
** on Ptr(N+1) and its subpages have values greater than Key(N).  And
** so forth.
**
** Finding a particular key requires reading O(log(M)) pages from the 
** disk where M is the number of entries in the tree.
**
** In this implementation, a single file can hold one or more separate 
** BTrees.  Each BTree is identified by the index of its root page.  The
** key and data for any entry are combined to form the "payload".  A
** fixed amount of payload can be carried directly on the database
** page.  If the payload is larger than the preset amount then surplus
** bytes are stored on overflow pages.  The payload for an entry
** and the preceding pointer are combined to form a "Cell".  Each 
** page has a small header which contains the Ptr(N+1) pointer and other
** information such as the size of key and data.
**
** FORMAT DETAILS
**
** The file is divided into pages.  The first page is called page 1,
** the second is page 2, and so forth.  A page number of zero indicates
** "no such page".  The page size can be anything between 512 and 65536.
** Each page can be either a btree page, a freelist page or an overflow
** page.
**
** The first page is always a btree page.  The first 100 bytes of the first
** page contain a special header (the "file header") that describes the file.
** The format of the file header is as follows:
**
**   OFFSET   SIZE    DESCRIPTION
**      0      16     Header string: "SQLite format 3\000"
**     16       2     Page size in bytes.  
**     18       1     File format write version
**     19       1     File format read version
**     20       1     Bytes of unused space at the end of each page
**     21       1     Max embedded payload fraction
**     22       1     Min embedded payload fraction
**     23       1     Min leaf payload fraction
**     24       4     File change counter
**     28       4     Reserved for future use
**     32       4     First freelist page
**     36       4     Number of freelist pages in the file
**     40      60     15 4-byte meta values passed to higher layers
**
** All of the integer values are big-endian (most significant byte first).
**
** The file change counter is incremented when the database is changed more
** than once within the same second.  This counter, together with the
** modification time of the file, allows other processes to know
** when the file has changed and thus when they need to flush their
** cache.
**
** The max embedded payload fraction is the amount of the total usable
** space in a page that can be consumed by a single cell for standard
** B-tree (non-LEAFDATA) tables.  A value of 255 means 100%.  The default
** is to limit the maximum cell size so that at least 4 cells will fit
** on one page.  Thus the default max embedded payload fraction is 64.
**
** If the payload for a cell is larger than the max payload, then extra
** payload is spilled to overflow pages.  Once an overflow page is allocated,
** as many bytes as possible are moved into the overflow pages without letting
** the cell size drop below the min embedded payload fraction.
**
** The min leaf payload fraction is like the min embedded payload fraction
** except that it applies to leaf nodes in a LEAFDATA tree.  The maximum
** payload fraction for a LEAFDATA tree is always 100% (or 255) and it
** not specified in the header.
**
** Each btree pages is divided into three sections:  The header, the
** cell pointer array, and the cell area area.  Page 1 also has a 100-byte
** file header that occurs before the page header.
**
**      |----------------|
**      | file header    |   100 bytes.  Page 1 only.
**      |----------------|
**      | page header    |   8 bytes for leaves.  12 bytes for interior nodes
**      |----------------|
**      | cell pointer   |   |  2 bytes per cell.  Sorted order.
**      | array          |   |  Grows downward
**      |                |   v
**      |----------------|
**      | unallocated    |
**      | space          |
**      |----------------|   ^  Grows upwards
**      | cell content   |   |  Arbitrary order interspersed with freeblocks.
**      | area           |   |  and free space fragments.
**      |----------------|
**
** The page headers looks like this:
**
**   OFFSET   SIZE     DESCRIPTION
**      0       1      Flags. 1: intkey, 2: zerodata, 4: leafdata, 8: leaf
**      1       2      byte offset to the first freeblock
**      3       2      number of cells on this page
**      5       2      first byte of the cell content area
**      7       1      number of fragmented free bytes
**      8       4      Right child (the Ptr(N+1) value).  Omitted on leaves.
**
** The flags define the format of this btree page.  The leaf flag means that
** this page has no children.  The zerodata flag means that this page carries
** only keys and no data.  The intkey flag means that the key is a integer
** which is stored in the key size entry of the cell header rather than in
** the payload area.
**
** The cell pointer array begins on the first byte after the page header.
** The cell pointer array contains zero or more 2-byte numbers which are
** offsets from the beginning of the page to the cell content in the cell
** content area.  The cell pointers occur in sorted order.  The system strives
** to keep free space after the last cell pointer so that new cells can
** be easily added without having to defragment the page.
**
** Cell content is stored at the very end of the page and grows toward the
** beginning of the page.
**
** Unused space within the cell content area is collected into a linked list of
** freeblocks.  Each freeblock is at least 4 bytes in size.  The byte offset
** to the first freeblock is given in the header.  Freeblocks occur in
** increasing order.  Because a freeblock must be at least 4 bytes in size,
** any group of 3 or fewer unused bytes in the cell content area cannot
** exist on the freeblock chain.  A group of 3 or fewer free bytes is called
** a fragment.  The total number of bytes in all fragments is recorded.
** in the page header at offset 7.
**
**    SIZE    DESCRIPTION
**      2     Byte offset of the next freeblock
**      2     Bytes in this freeblock
**
** Cells are of variable length.  Cells are stored in the cell content area at
** the end of the page.  Pointers to the cells are in the cell pointer array
** that immediately follows the page header.  Cells is not necessarily
** contiguous or in order, but cell pointers are contiguous and in order.
**
** Cell content makes use of variable length integers.  A variable
** length integer is 1 to 9 bytes where the lower 7 bits of each 
** byte are used.  The integer consists of all bytes that have bit 8 set and
** the first byte with bit 8 clear.  The most significant byte of the integer
** appears first.  A variable-length integer may not be more than 9 bytes long.
** As a special case, all 8 bytes of the 9th byte are used as data.  This
** allows a 64-bit integer to be encoded in 9 bytes.
**
**    0x00                      becomes  0x00000000
**    0x7f                      becomes  0x0000007f
**    0x81 0x00                 becomes  0x00000080
**    0x82 0x00                 becomes  0x00000100
**    0x80 0x7f                 becomes  0x0000007f
**    0x8a 0x91 0xd1 0xac 0x78  becomes  0x12345678
**    0x81 0x81 0x81 0x81 0x01  becomes  0x10204081
**
** Variable length integers are used for rowids and to hold the number of
** bytes of key and data in a btree cell.
**
** The content of a cell looks like this:
**
**    SIZE    DESCRIPTION
**      4     Page number of the left child. Omitted if leaf flag is set.
**     var    Number of bytes of data. Omitted if the zerodata flag is set.
**     var    Number of bytes of key. Or the key itself if intkey flag is set.
**      *     Payload
**      4     First page of the overflow chain.  Omitted if no overflow
**
** Overflow pages form a linked list.  Each page except the last is completely
** filled with data (pagesize - 4 bytes).  The last page can have as little
** as 1 byte of data.
**
**    SIZE    DESCRIPTION
**      4     Page number of next overflow page
**      *     Data
**
** Freelist pages come in two subtypes: trunk pages and leaf pages.  The
** file header points to first in a linked list of trunk page.  Each trunk
** page points to multiple leaf pages.  The content of a leaf page is
** unspecified.  A trunk page looks like this:
**
**    SIZE    DESCRIPTION
**      4     Page number of next trunk page
**      4     Number of leaf pointers on this page
**      *     zero or more pages numbers of leaves
*/
#include "sqliteInt.h"
#include "pager.h"
#include "btree.h"
#include "os.h"
#include <assert.h>

/*
** This macro rounds values up so that if the value is an address it
** is guaranteed to be an address that is aligned to an 8-byte boundary.
*/
#define FORCE_ALIGNMENT(X)   (((X)+7)&~7)

/* The following value is the maximum cell size assuming a maximum page
** size give above.
*/
#define MX_CELL_SIZE(pBt)  (pBt->pageSize-8)

/* The maximum number of cells on a single page of the database.  This
** assumes a minimum cell size of 3 bytes.  Such small cells will be
** exceedingly rare, but they are possible.
*/
#define MX_CELL(pBt) ((pBt->pageSize-8)/3)

/* Forward declarations */
typedef struct MemPage MemPage;

/*
** This is a magic string that appears at the beginning of every
** SQLite database in order to identify the file as a real database.
**                                  123456789 123456 */
static const char zMagicHeader[] = "SQLite format 3";

/*
** Page type flags.  An ORed combination of these flags appear as the
** first byte of every BTree page.
*/
#define PTF_INTKEY    0x01
#define PTF_ZERODATA  0x02
#define PTF_LEAFDATA  0x04
#define PTF_LEAF      0x08

/*
** As each page of the file is loaded into memory, an instance of the following
** structure is appended and initialized to zero.  This structure stores
** information about the page that is decoded from the raw file page.
**
** The pParent field points back to the parent page.  This allows us to
** walk up the BTree from any leaf to the root.  Care must be taken to
** unref() the parent page pointer when this page is no longer referenced.
** The pageDestructor() routine handles that chore.
*/
struct MemPage {
  u8 isInit;           /* True if previously initialized. MUST BE FIRST! */
  u8 idxShift;         /* True if Cell indices have changed */
  u8 nOverflow;        /* Number of overflow cell bodies in aCell[] */
  u8 intKey;           /* True if intkey flag is set */
  u8 leaf;             /* True if leaf flag is set */
  u8 zeroData;         /* True if table stores keys only */
  u8 leafData;         /* True if tables stores data on leaves only */
  u8 hasData;          /* True if this page stores data */
  u8 hdrOffset;        /* 100 for page 1.  0 otherwise */
  u8 childPtrSize;     /* 0 if leaf==1.  4 if leaf==0 */
  u16 maxLocal;        /* Copy of Btree.maxLocal or Btree.maxLeaf */
  u16 minLocal;        /* Copy of Btree.minLocal or Btree.minLeaf */
  u16 cellOffset;      /* Index in aData of first cell pointer */
  u16 idxParent;       /* Index in parent of this node */
  u16 nFree;           /* Number of free bytes on the page */
  u16 nCell;           /* Number of cells on this page, local and ovfl */
  struct _OvflCell {   /* Cells that will not fit on aData[] */
    u8 *pCell;           /* Pointers to the body of the overflow cell */
    u16 idx;             /* Insert this cell before idx-th non-overflow cell */
  } aOvfl[5];
  struct Btree *pBt;   /* Pointer back to BTree structure */
  u8 *aData;           /* Pointer back to the start of the page */
  Pgno pgno;           /* Page number for this page */
  MemPage *pParent;    /* The parent of this page.  NULL for root */
};

/*
** The in-memory image of a disk page has the auxiliary information appended
** to the end.  EXTRA_SIZE is the number of bytes of space needed to hold
** that extra information.
*/
#define EXTRA_SIZE sizeof(MemPage)

/*
** Everything we need to know about an open database
*/
struct Btree {
  Pager *pPager;        /* The page cache */
  BtCursor *pCursor;    /* A list of all open cursors */
  MemPage *pPage1;      /* First page of the database */
  u8 inTrans;           /* True if a transaction is in progress */
  u8 inStmt;            /* True if we are in a statement subtransaction */
  u8 readOnly;          /* True if the underlying file is readonly */
  u8 maxEmbedFrac;      /* Maximum payload as % of total page size */
  u8 minEmbedFrac;      /* Minimum payload as % of total page size */
  u8 minLeafFrac;       /* Minimum leaf payload as % of total page size */
  u8 pageSizeFixed;     /* True if the page size can no longer be changed */
#ifndef SQLITE_OMIT_AUTOVACUUM
  u8 autoVacuum;        /* True if database supports auto-vacuum */
#endif
  u16 pageSize;         /* Total number of bytes on a page */
  u16 psAligned;        /* pageSize rounded up to a multiple of 8 */
  u16 usableSize;       /* Number of usable bytes on each page */
  int maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
  int minLocal;         /* Minimum local payload in non-LEAFDATA tables */
  int maxLeaf;          /* Maximum local payload in a LEAFDATA table */
  int minLeaf;          /* Minimum local payload in a LEAFDATA table */
};
typedef Btree Bt;

/*
** Btree.inTrans may take one of the following values.
*/
#define TRANS_NONE  0
#define TRANS_READ  1
#define TRANS_WRITE 2

/*
** An instance of the following structure is used to hold information
** about a cell.  The parseCellPtr() function fills in this structure
** based on information extract from the raw disk page.
*/
typedef struct CellInfo CellInfo;
struct CellInfo {
  u8 *pCell;     /* Pointer to the start of cell content */
  i64 nKey;      /* The key for INTKEY tables, or number of bytes in key */
  u32 nData;     /* Number of bytes of data */
  u16 nHeader;   /* Size of the cell content header in bytes */
  u16 nLocal;    /* Amount of payload held locally */
  u16 iOverflow; /* Offset to overflow page number.  Zero if no overflow */
  u16 nSize;     /* Size of the cell content on the main b-tree page */
};

/*
** A cursor is a pointer to a particular entry in the BTree.
** The entry is identified by its MemPage and the index in
** MemPage.aCell[] of the entry.
*/
struct BtCursor {
  Btree *pBt;               /* The Btree to which this cursor belongs */
  BtCursor *pNext, *pPrev;  /* Forms a linked list of all cursors */
  int (*xCompare)(void*,int,const void*,int,const void*); /* Key comp func */
  void *pArg;               /* First arg to xCompare() */
  Pgno pgnoRoot;            /* The root page of this tree */
  MemPage *pPage;           /* Page that contains the entry */
  int idx;                  /* Index of the entry in pPage->aCell[] */
  CellInfo info;            /* A parse of the cell we are pointing at */
  u8 wrFlag;                /* True if writable */
  u8 isValid;               /* TRUE if points to a valid entry */
};

/*
** The TRACE macro will print high-level status information about the
** btree operation when the global variable sqlite3_btree_trace is
** enabled.
*/
#if SQLITE_TEST
# define TRACE(X)   if( sqlite3_btree_trace )\
                        { sqlite3DebugPrintf X; fflush(stdout); }
#else
# define TRACE(X)
#endif
int sqlite3_btree_trace=0;  /* True to enable tracing */

/*
** Forward declaration
*/
static int checkReadLocks(Btree*,Pgno,BtCursor*);

/*
** Read or write a two- and four-byte big-endian integer values.
*/
static u32 get2byte(unsigned char *p){
  return (p[0]<<8) | p[1];
}
static u32 get4byte(unsigned char *p){
  return (p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
}
static void put2byte(unsigned char *p, u32 v){
  p[0] = v>>8;
  p[1] = v;
}
static void put4byte(unsigned char *p, u32 v){
  p[0] = v>>24;
  p[1] = v>>16;
  p[2] = v>>8;
  p[3] = v;
}

/*
** Routines to read and write variable-length integers.  These used to
** be defined locally, but now we use the varint routines in the util.c
** file.
*/
#define getVarint    sqlite3GetVarint
#define getVarint32  sqlite3GetVarint32
#define putVarint    sqlite3PutVarint

/* The database page the PENDING_BYTE occupies. This page is never used.
** TODO: This macro is very similary to PAGER_MJ_PGNO() in pager.c. They
** should possibly be consolidated (presumably in pager.h).
*/
#define PENDING_BYTE_PAGE(pBt) ((PENDING_BYTE/(pBt)->pageSize)+1)

#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** These macros define the location of the pointer-map entry for a 
** database page. The first argument to each is the number of usable
** bytes on each page of the database (often 1024). The second is the
** page number to look up in the pointer map.
**
** PTRMAP_PAGENO returns the database page number of the pointer-map
** page that stores the required pointer. PTRMAP_PTROFFSET returns
** the offset of the requested map entry.
**
** If the pgno argument passed to PTRMAP_PAGENO is a pointer-map page,
** then pgno is returned. So (pgno==PTRMAP_PAGENO(pgsz, pgno)) can be
** used to test if pgno is a pointer-map page. PTRMAP_ISPAGE implements
** this test.
*/
#define PTRMAP_PAGENO(pgsz, pgno) (((pgno-2)/(pgsz/5+1))*(pgsz/5+1)+2)
#define PTRMAP_PTROFFSET(pgsz, pgno) (((pgno-2)%(pgsz/5+1)-1)*5)
#define PTRMAP_ISPAGE(pgsz, pgno) (PTRMAP_PAGENO(pgsz,pgno)==pgno)

/*
** The pointer map is a lookup table that identifies the parent page for
** each child page in the database file.  The parent page is the page that
** contains a pointer to the child.  Every page in the database contains
** 0 or 1 parent pages.  (In this context 'database page' refers
** to any page that is not part of the pointer map itself.)  Each pointer map
** entry consists of a single byte 'type' and a 4 byte parent page number.
** The PTRMAP_XXX identifiers below are the valid types.
**
** The purpose of the pointer map is to facility moving pages from one
** position in the file to another as part of autovacuum.  When a page
** is moved, the pointer in its parent must be updated to point to the
** new location.  The pointer map is used to locate the parent page quickly.
**
** PTRMAP_ROOTPAGE: The database page is a root-page. The page-number is not
**                  used in this case.
**
** PTRMAP_FREEPAGE: The database page is an unused (free) page. The page-number 
**                  is not used in this case.
**
** PTRMAP_OVERFLOW1: The database page is the first page in a list of 
**                   overflow pages. The page number identifies the page that
**                   contains the cell with a pointer to this overflow page.
**
** PTRMAP_OVERFLOW2: The database page is the second or later page in a list of
**                   overflow pages. The page-number identifies the previous
**                   page in the overflow page list.
**
** PTRMAP_BTREE: The database page is a non-root btree page. The page number
**               identifies the parent page in the btree.
*/
#define PTRMAP_ROOTPAGE 1
#define PTRMAP_FREEPAGE 2
#define PTRMAP_OVERFLOW1 3
#define PTRMAP_OVERFLOW2 4
#define PTRMAP_BTREE 5

/*
** Write an entry into the pointer map.
**
** This routine updates the pointer map entry for page number 'key'
** so that it maps to type 'eType' and parent page number 'pgno'.
** An error code is returned if something goes wrong, otherwise SQLITE_OK.
*/
static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno parent){
  u8 *pPtrmap;    /* The pointer map page */
  Pgno iPtrmap;   /* The pointer map page number */
  int offset;     /* Offset in pointer map page */
  int rc;

  assert( pBt->autoVacuum );
  if( key==0 ){
    return SQLITE_CORRUPT;
  }
  iPtrmap = PTRMAP_PAGENO(pBt->usableSize, key);
  rc = sqlite3pager_get(pBt->pPager, iPtrmap, (void **)&pPtrmap);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  offset = PTRMAP_PTROFFSET(pBt->usableSize, key);

  if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=parent ){
    TRACE(("PTRMAP_UPDATE: %d->(%d,%d)\n", key, eType, parent));
    rc = sqlite3pager_write(pPtrmap);
    if( rc==SQLITE_OK ){
      pPtrmap[offset] = eType;
      put4byte(&pPtrmap[offset+1], parent);
    }
  }

  sqlite3pager_unref(pPtrmap);
  return rc;
}

/*
** Read an entry from the pointer map.
**
** This routine retrieves the pointer map entry for page 'key', writing
** the type and parent page number to *pEType and *pPgno respectively.
** An error code is returned if something goes wrong, otherwise SQLITE_OK.
*/
static int ptrmapGet(Btree *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
  int iPtrmap;       /* Pointer map page index */
  u8 *pPtrmap;       /* Pointer map page data */
  int offset;        /* Offset of entry in pointer map */
  int rc;

  iPtrmap = PTRMAP_PAGENO(pBt->usableSize, key);
  rc = sqlite3pager_get(pBt->pPager, iPtrmap, (void **)&pPtrmap);
  if( rc!=0 ){
    return rc;
  }

  offset = PTRMAP_PTROFFSET(pBt->usableSize, key);
  if( pEType ) *pEType = pPtrmap[offset];
  if( pPgno ) *pPgno = get4byte(&pPtrmap[offset+1]);

  sqlite3pager_unref(pPtrmap);
  if( *pEType<1 || *pEType>5 ) return SQLITE_CORRUPT;
  return SQLITE_OK;
}

#endif /* SQLITE_OMIT_AUTOVACUUM */

/*
** Given a btree page and a cell index (0 means the first cell on
** the page, 1 means the second cell, and so forth) return a pointer
** to the cell content.
**
** This routine works only for pages that do not contain overflow cells.
*/
static u8 *findCell(MemPage *pPage, int iCell){
  u8 *data = pPage->aData;
  assert( iCell>=0 );
  assert( iCell<get2byte(&data[pPage->hdrOffset+3]) );
  return data + get2byte(&data[pPage->cellOffset+2*iCell]);
}

/*
** This a more complex version of findCell() that works for
** pages that do contain overflow cells.  See insert
*/
static u8 *findOverflowCell(MemPage *pPage, int iCell){
  int i;
  for(i=pPage->nOverflow-1; i>=0; i--){
    int k;
    struct _OvflCell *pOvfl;
    pOvfl = &pPage->aOvfl[i];
    k = pOvfl->idx;
    if( k<=iCell ){
      if( k==iCell ){
        return pOvfl->pCell;
      }
      iCell--;
    }
  }
  return findCell(pPage, iCell);
}

/*
** Parse a cell content block and fill in the CellInfo structure.  There
** are two versions of this function.  parseCell() takes a cell index
** as the second argument and parseCellPtr() takes a pointer to the
** body of the cell as its second argument.
*/
static void parseCellPtr(
  MemPage *pPage,         /* Page containing the cell */
  u8 *pCell,              /* Pointer to the cell text. */
  CellInfo *pInfo         /* Fill in this structure */
){
  int n;                  /* Number bytes in cell content header */
  u32 nPayload;           /* Number of bytes of cell payload */

  pInfo->pCell = pCell;
  assert( pPage->leaf==0 || pPage->leaf==1 );
  n = pPage->childPtrSize;
  assert( n==4-4*pPage->leaf );
  if( pPage->hasData ){
    n += getVarint32(&pCell[n], &nPayload);
  }else{
    nPayload = 0;
  }
  n += getVarint(&pCell[n], (u64 *)&pInfo->nKey);
  pInfo->nHeader = n;
  pInfo->nData = nPayload;
  if( !pPage->intKey ){
    nPayload += pInfo->nKey;
  }
  if( nPayload<=pPage->maxLocal ){
    /* This is the (easy) common case where the entire payload fits
    ** on the local page.  No overflow is required.
    */
    int nSize;          /* Total size of cell content in bytes */
    pInfo->nLocal = nPayload;
    pInfo->iOverflow = 0;
    nSize = nPayload + n;
    if( nSize<4 ){
      nSize = 4;        /* Minimum cell size is 4 */
    }
    pInfo->nSize = nSize;
  }else{
    /* If the payload will not fit completely on the local page, we have
    ** to decide how much to store locally and how much to spill onto
    ** overflow pages.  The strategy is to minimize the amount of unused
    ** space on overflow pages while keeping the amount of local storage
    ** in between minLocal and maxLocal.
    **
    ** Warning:  changing the way overflow payload is distributed in any
    ** way will result in an incompatible file format.
    */
    int minLocal;  /* Minimum amount of payload held locally */
    int maxLocal;  /* Maximum amount of payload held locally */
    int surplus;   /* Overflow payload available for local storage */

    minLocal = pPage->minLocal;
    maxLocal = pPage->maxLocal;
    surplus = minLocal + (nPayload - minLocal)%(pPage->pBt->usableSize - 4);
    if( surplus <= maxLocal ){
      pInfo->nLocal = surplus;
    }else{
      pInfo->nLocal = minLocal;
    }
    pInfo->iOverflow = pInfo->nLocal + n;
    pInfo->nSize = pInfo->iOverflow + 4;
  }
}
static void parseCell(
  MemPage *pPage,         /* Page containing the cell */
  int iCell,              /* The cell index.  First cell is 0 */
  CellInfo *pInfo         /* Fill in this structure */
){
  parseCellPtr(pPage, findCell(pPage, iCell), pInfo);
}

/*
** Compute the total number of bytes that a Cell needs in the cell
** data area of the btree-page.  The return number includes the cell
** data header and the local payload, but not any overflow page or
** the space used by the cell pointer.
*/
#ifndef NDEBUG
static int cellSize(MemPage *pPage, int iCell){
  CellInfo info;
  parseCell(pPage, iCell, &info);
  return info.nSize;
}
#endif
static int cellSizePtr(MemPage *pPage, u8 *pCell){
  CellInfo info;
  parseCellPtr(pPage, pCell, &info);
  return info.nSize;
}

#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** If the cell pCell, part of page pPage contains a pointer
** to an overflow page, insert an entry into the pointer-map
** for the overflow page.
*/
static int ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell){
  if( pCell ){
    CellInfo info;
    parseCellPtr(pPage, pCell, &info);
    if( (info.nData+(pPage->intKey?0:info.nKey))>info.nLocal ){
      Pgno ovfl = get4byte(&pCell[info.iOverflow]);
      return ptrmapPut(pPage->pBt, ovfl, PTRMAP_OVERFLOW1, pPage->pgno);
    }
  }
  return SQLITE_OK;
}
/*
** If the cell with index iCell on page pPage contains a pointer
** to an overflow page, insert an entry into the pointer-map
** for the overflow page.
*/
static int ptrmapPutOvfl(MemPage *pPage, int iCell){
  u8 *pCell;
  pCell = findOverflowCell(pPage, iCell);
  return ptrmapPutOvflPtr(pPage, pCell);
}
#endif


/*
** Do sanity checking on a page.  Throw an exception if anything is
** not right.
**
** This routine is used for internal error checking only.  It is omitted
** from most builds.
*/
#if defined(BTREE_DEBUG) && !defined(NDEBUG) && 0
static void _pageIntegrity(MemPage *pPage){
  int usableSize;
  u8 *data;
  int i, j, idx, c, pc, hdr, nFree;
  int cellOffset;
  int nCell, cellLimit;
  u8 *used;

  used = sqliteMallocRaw( pPage->pBt->pageSize );
  if( used==0 ) return;
  usableSize = pPage->pBt->usableSize;
  assert( pPage->aData==&((unsigned char*)pPage)[-pPage->pBt->psAligned] );
  hdr = pPage->hdrOffset;
  assert( hdr==(pPage->pgno==1 ? 100 : 0) );
  assert( pPage->pgno==sqlite3pager_pagenumber(pPage->aData) );
  c = pPage->aData[hdr];
  if( pPage->isInit ){
    assert( pPage->leaf == ((c & PTF_LEAF)!=0) );
    assert( pPage->zeroData == ((c & PTF_ZERODATA)!=0) );
    assert( pPage->leafData == ((c & PTF_LEAFDATA)!=0) );
    assert( pPage->intKey == ((c & (PTF_INTKEY|PTF_LEAFDATA))!=0) );
    assert( pPage->hasData ==
             !(pPage->zeroData || (!pPage->leaf && pPage->leafData)) );
    assert( pPage->cellOffset==pPage->hdrOffset+12-4*pPage->leaf );
    assert( pPage->nCell = get2byte(&pPage->aData[hdr+3]) );
  }
  data = pPage->aData;
  memset(used, 0, usableSize);
  for(i=0; i<hdr+10-pPage->leaf*4; i++) used[i] = 1;
  nFree = 0;
  pc = get2byte(&data[hdr+1]);
  while( pc ){
    int size;
    assert( pc>0 && pc<usableSize-4 );
    size = get2byte(&data[pc+2]);
    assert( pc+size<=usableSize );
    nFree += size;
    for(i=pc; i<pc+size; i++){
      assert( used[i]==0 );
      used[i] = 1;
    }
    pc = get2byte(&data[pc]);
  }
  idx = 0;
  nCell = get2byte(&data[hdr+3]);
  cellLimit = get2byte(&data[hdr+5]);
  assert( pPage->isInit==0 
         || pPage->nFree==nFree+data[hdr+7]+cellLimit-(cellOffset+2*nCell) );
  cellOffset = pPage->cellOffset;
  for(i=0; i<nCell; i++){
    int size;
    pc = get2byte(&data[cellOffset+2*i]);
    assert( pc>0 && pc<usableSize-4 );
    size = cellSize(pPage, &data[pc]);
    assert( pc+size<=usableSize );
    for(j=pc; j<pc+size; j++){
      assert( used[j]==0 );
      used[j] = 1;
    }
  }
  for(i=cellOffset+2*nCell; i<cellimit; i++){
    assert( used[i]==0 );
    used[i] = 1;
  }
  nFree = 0;
  for(i=0; i<usableSize; i++){
    assert( used[i]<=1 );
    if( used[i]==0 ) nFree++;
  }
  assert( nFree==data[hdr+7] );
  sqliteFree(used);
}
#define pageIntegrity(X) _pageIntegrity(X)
#else
# define pageIntegrity(X)
#endif

/*
** Defragment the page given.  All Cells are moved to the
** beginning of the page and all free space is collected 
** into one big FreeBlk at the end of the page.
*/
static int defragmentPage(MemPage *pPage){
  int i;                     /* Loop counter */
  int pc;                    /* Address of a i-th cell */
  int addr;                  /* Offset of first byte after cell pointer array */
  int hdr;                   /* Offset to the page header */
  int size;                  /* Size of a cell */
  int usableSize;            /* Number of usable bytes on a page */
  int cellOffset;            /* Offset to the cell pointer array */
  int brk;                   /* Offset to the cell content area */
  int nCell;                 /* Number of cells on the page */
  unsigned char *data;       /* The page data */
  unsigned char *temp;       /* Temp area for cell content */

  assert( sqlite3pager_iswriteable(pPage->aData) );
  assert( pPage->pBt!=0 );
  assert( pPage->pBt->usableSize <= SQLITE_MAX_PAGE_SIZE );
  assert( pPage->nOverflow==0 );
  temp = sqliteMalloc( pPage->pBt->pageSize );
  if( temp==0 ) return SQLITE_NOMEM;
  data = pPage->aData;
  hdr = pPage->hdrOffset;
  cellOffset = pPage->cellOffset;
  nCell = pPage->nCell;
  assert( nCell==get2byte(&data[hdr+3]) );
  usableSize = pPage->pBt->usableSize;
  brk = get2byte(&data[hdr+5]);
  memcpy(&temp[brk], &data[brk], usableSize - brk);
  brk = usableSize;
  for(i=0; i<nCell; i++){
    u8 *pAddr;     /* The i-th cell pointer */
    pAddr = &data[cellOffset + i*2];
    pc = get2byte(pAddr);
    assert( pc<pPage->pBt->usableSize );
    size = cellSizePtr(pPage, &temp[pc]);
    brk -= size;
    memcpy(&data[brk], &temp[pc], size);
    put2byte(pAddr, brk);
  }
  assert( brk>=cellOffset+2*nCell );
  put2byte(&data[hdr+5], brk);
  data[hdr+1] = 0;
  data[hdr+2] = 0;
  data[hdr+7] = 0;
  addr = cellOffset+2*nCell;
  memset(&data[addr], 0, brk-addr);
  sqliteFree(temp);
  return SQLITE_OK;
}

/*
** Allocate nByte bytes of space on a page.
**
** Return the index into pPage->aData[] of the first byte of
** the new allocation. Or return 0 if there is not enough free
** space on the page to satisfy the allocation request.
**
** If the page contains nBytes of free space but does not contain
** nBytes of contiguous free space, then this routine automatically
** calls defragementPage() to consolidate all free space before 
** allocating the new chunk.
*/
static int allocateSpace(MemPage *pPage, int nByte){
  int addr, pc, hdr;
  int size;
  int nFrag;
  int top;
  int nCell;
  int cellOffset;
  unsigned char *data;
  
  data = pPage->aData;
  assert( sqlite3pager_iswriteable(data) );
  assert( pPage->pBt );
  if( nByte<4 ) nByte = 4;
  if( pPage->nFree<nByte || pPage->nOverflow>0 ) return 0;
  pPage->nFree -= nByte;
  hdr = pPage->hdrOffset;

  nFrag = data[hdr+7];
  if( nFrag<60 ){
    /* Search the freelist looking for a slot big enough to satisfy the
    ** space request. */
    addr = hdr+1;
    while( (pc = get2byte(&data[addr]))>0 ){
      size = get2byte(&data[pc+2]);
      if( size>=nByte ){
        if( size<nByte+4 ){
          memcpy(&data[addr], &data[pc], 2);
          data[hdr+7] = nFrag + size - nByte;
          return pc;
        }else{
          put2byte(&data[pc+2], size-nByte);
          return pc + size - nByte;
        }
      }
      addr = pc;
    }
  }

  /* Allocate memory from the gap in between the cell pointer array
  ** and the cell content area.
  */
  top = get2byte(&data[hdr+5]);
  nCell = get2byte(&data[hdr+3]);
  cellOffset = pPage->cellOffset;
  if( nFrag>=60 || cellOffset + 2*nCell > top - nByte ){
    if( defragmentPage(pPage) ) return 0;
    top = get2byte(&data[hdr+5]);
  }
  top -= nByte;
  assert( cellOffset + 2*nCell <= top );
  put2byte(&data[hdr+5], top);
  return top;
}

/*
** Return a section of the pPage->aData to the freelist.
** The first byte of the new free block is pPage->aDisk[start]
** and the size of the block is "size" bytes.
**
** Most of the effort here is involved in coalesing adjacent
** free blocks into a single big free block.
*/
static void freeSpace(MemPage *pPage, int start, int size){
  int addr, pbegin, hdr;
  unsigned char *data = pPage->aData;

  assert( pPage->pBt!=0 );
  assert( sqlite3pager_iswriteable(data) );
  assert( start>=pPage->hdrOffset+6+(pPage->leaf?0:4) );
  assert( (start + size)<=pPage->pBt->usableSize );
  if( size<4 ) size = 4;

  /* Add the space back into the linked list of freeblocks */
  hdr = pPage->hdrOffset;
  addr = hdr + 1;
  while( (pbegin = get2byte(&data[addr]))<start && pbegin>0 ){
    assert( pbegin<=pPage->pBt->usableSize-4 );
    assert( pbegin>addr );
    addr = pbegin;
  }
  assert( pbegin<=pPage->pBt->usableSize-4 );
  assert( pbegin>addr || pbegin==0 );
  put2byte(&data[addr], start);
  put2byte(&data[start], pbegin);
  put2byte(&data[start+2], size);
  pPage->nFree += size;

  /* Coalesce adjacent free blocks */
  addr = pPage->hdrOffset + 1;
  while( (pbegin = get2byte(&data[addr]))>0 ){
    int pnext, psize;
    assert( pbegin>addr );
    assert( pbegin<=pPage->pBt->usableSize-4 );
    pnext = get2byte(&data[pbegin]);
    psize = get2byte(&data[pbegin+2]);
    if( pbegin + psize + 3 >= pnext && pnext>0 ){
      int frag = pnext - (pbegin+psize);
      assert( frag<=data[pPage->hdrOffset+7] );
      data[pPage->hdrOffset+7] -= frag;
      put2byte(&data[pbegin], get2byte(&data[pnext]));
      put2byte(&data[pbegin+2], pnext+get2byte(&data[pnext+2])-pbegin);
    }else{
      addr = pbegin;
    }
  }

  /* If the cell content area begins with a freeblock, remove it. */
  if( data[hdr+1]==data[hdr+5] && data[hdr+2]==data[hdr+6] ){
    int top;
    pbegin = get2byte(&data[hdr+1]);
    memcpy(&data[hdr+1], &data[pbegin], 2);
    top = get2byte(&data[hdr+5]);
    put2byte(&data[hdr+5], top + get2byte(&data[pbegin+2]));
  }
}

/*
** Decode the flags byte (the first byte of the header) for a page
** and initialize fields of the MemPage structure accordingly.
*/
static void decodeFlags(MemPage *pPage, int flagByte){
  Btree *pBt;     /* A copy of pPage->pBt */

  assert( pPage->hdrOffset==(pPage->pgno==1 ? 100 : 0) );
  pPage->intKey = (flagByte & (PTF_INTKEY|PTF_LEAFDATA))!=0;
  pPage->zeroData = (flagByte & PTF_ZERODATA)!=0;
  pPage->leaf = (flagByte & PTF_LEAF)!=0;
  pPage->childPtrSize = 4*(pPage->leaf==0);
  pBt = pPage->pBt;
  if( flagByte & PTF_LEAFDATA ){
    pPage->leafData = 1;
    pPage->maxLocal = pBt->maxLeaf;
    pPage->minLocal = pBt->minLeaf;
  }else{
    pPage->leafData = 0;
    pPage->maxLocal = pBt->maxLocal;
    pPage->minLocal = pBt->minLocal;
  }
  pPage->hasData = !(pPage->zeroData || (!pPage->leaf && pPage->leafData));
}

/*
** Initialize the auxiliary information for a disk block.
**
** The pParent parameter must be a pointer to the MemPage which
** is the parent of the page being initialized.  The root of a
** BTree has no parent and so for that page, pParent==NULL.
**
** Return SQLITE_OK on success.  If we see that the page does
** not contain a well-formed database page, then return 
** SQLITE_CORRUPT.  Note that a return of SQLITE_OK does not
** guarantee that the page is well-formed.  It only shows that
** we failed to detect any corruption.
*/
static int initPage(
  MemPage *pPage,        /* The page to be initialized */
  MemPage *pParent       /* The parent.  Might be NULL */
){
  int pc;            /* Address of a freeblock within pPage->aData[] */
  int hdr;           /* Offset to beginning of page header */
  u8 *data;          /* Equal to pPage->aData */
  Btree *pBt;        /* The main btree structure */
  int usableSize;    /* Amount of usable space on each page */
  int cellOffset;    /* Offset from start of page to first cell pointer */
  int nFree;         /* Number of unused bytes on the page */
  int top;           /* First byte of the cell content area */

  pBt = pPage->pBt;
  assert( pBt!=0 );
  assert( pParent==0 || pParent->pBt==pBt );
  assert( pPage->pgno==sqlite3pager_pagenumber(pPage->aData) );
  assert( pPage->aData == &((unsigned char*)pPage)[-pBt->psAligned] );
  if( pPage->pParent!=pParent && (pPage->pParent!=0 || pPage->isInit) ){
    /* The parent page should never change unless the file is corrupt */
    return SQLITE_CORRUPT; /* bkpt-CORRUPT */
  }
  if( pPage->isInit ) return SQLITE_OK;
  if( pPage->pParent==0 && pParent!=0 ){
    pPage->pParent = pParent;
    sqlite3pager_ref(pParent->aData);
  }
  hdr = pPage->hdrOffset;
  data = pPage->aData;
  decodeFlags(pPage, data[hdr]);
  pPage->nOverflow = 0;
  pPage->idxShift = 0;
  usableSize = pBt->usableSize;
  pPage->cellOffset = cellOffset = hdr + 12 - 4*pPage->leaf;
  top = get2byte(&data[hdr+5]);
  pPage->nCell = get2byte(&data[hdr+3]);
  if( pPage->nCell>MX_CELL(pBt) ){
    /* To many cells for a single page.  The page must be corrupt */
    return SQLITE_CORRUPT; /* bkpt-CORRUPT */
  }
  if( pPage->nCell==0 && pParent!=0 && pParent->pgno!=1 ){
    /* All pages must have at least one cell, except for root pages */
    return SQLITE_CORRUPT; /* bkpt-CORRUPT */
  }

  /* Compute the total free space on the page */
  pc = get2byte(&data[hdr+1]);
  nFree = data[hdr+7] + top - (cellOffset + 2*pPage->nCell);
  while( pc>0 ){
    int next, size;
    if( pc>usableSize-4 ){
      /* Free block is off the page */
      return SQLITE_CORRUPT;  /* bkpt-CORRUPT */
    }
    next = get2byte(&data[pc]);
    size = get2byte(&data[pc+2]);
    if( next>0 && next<=pc+size+3 ){
      /* Free blocks must be in accending order */
      return SQLITE_CORRUPT;  /* bkpt-CORRUPT */
    }
    nFree += size;
    pc = next;
  }
  pPage->nFree = nFree;
  if( nFree>=usableSize ){
    /* Free space cannot exceed total page size */
    return SQLITE_CORRUPT;  /* bkpt-CORRUPT */
  }

  pPage->isInit = 1;
  pageIntegrity(pPage);
  return SQLITE_OK;
}

/*
** Set up a raw page so that it looks like a database page holding
** no entries.
*/
static void zeroPage(MemPage *pPage, int flags){
  unsigned char *data = pPage->aData;
  Btree *pBt = pPage->pBt;
  int hdr = pPage->hdrOffset;
  int first;

  assert( sqlite3pager_pagenumber(data)==pPage->pgno );
  assert( &data[pBt->psAligned] == (unsigned char*)pPage );
  assert( sqlite3pager_iswriteable(data) );
  memset(&data[hdr], 0, pBt->usableSize - hdr);
  data[hdr] = flags;
  first = hdr + 8 + 4*((flags&PTF_LEAF)==0);
  memset(&data[hdr+1], 0, 4);
  data[hdr+7] = 0;
  put2byte(&data[hdr+5], pBt->usableSize);
  pPage->nFree = pBt->usableSize - first;
  decodeFlags(pPage, flags);
  pPage->hdrOffset = hdr;
  pPage->cellOffset = first;
  pPage->nOverflow = 0;
  pPage->idxShift = 0;
  pPage->nCell = 0;
  pPage->isInit = 1;
  pageIntegrity(pPage);
}

/*
** Get a page from the pager.  Initialize the MemPage.pBt and
** MemPage.aData elements if needed.
*/
static int getPage(Btree *pBt, Pgno pgno, MemPage **ppPage){
  int rc;
  unsigned char *aData;
  MemPage *pPage;
  rc = sqlite3pager_get(pBt->pPager, pgno, (void**)&aData);
  if( rc ) return rc;
  pPage = (MemPage*)&aData[pBt->psAligned];
  pPage->aData = aData;
  pPage->pBt = pBt;
  pPage->pgno = pgno;
  pPage->hdrOffset = pPage->pgno==1 ? 100 : 0;
  *ppPage = pPage;
  return SQLITE_OK;
}

/*
** Get a page from the pager and initialize it.  This routine
** is just a convenience wrapper around separate calls to
** getPage() and initPage().
*/
static int getAndInitPage(
  Btree *pBt,          /* The database file */
  Pgno pgno,           /* Number of the page to get */
  MemPage **ppPage,    /* Write the page pointer here */
  MemPage *pParent     /* Parent of the page */
){
  int rc;
  if( pgno==0 ){
    return SQLITE_CORRUPT;  /* bkpt-CORRUPT */
  }
  rc = getPage(pBt, pgno, ppPage);
  if( rc==SQLITE_OK && (*ppPage)->isInit==0 ){
    rc = initPage(*ppPage, pParent);
  }
  return rc;
}

/*
** Release a MemPage.  This should be called once for each prior
** call to getPage.
*/
static void releasePage(MemPage *pPage){
  if( pPage ){
    assert( pPage->aData );
    assert( pPage->pBt );
    assert( &pPage->aData[pPage->pBt->psAligned]==(unsigned char*)pPage );
    sqlite3pager_unref(pPage->aData);
  }
}

/*
** This routine is called when the reference count for a page
** reaches zero.  We need to unref the pParent pointer when that
** happens.
*/
static void pageDestructor(void *pData, int pageSize){
  MemPage *pPage = (MemPage*)&((char*)pData)[FORCE_ALIGNMENT(pageSize)];
  if( pPage->pParent ){
    MemPage *pParent = pPage->pParent;
    pPage->pParent = 0;
    releasePage(pParent);
  }
  pPage->isInit = 0;
}

/*
** During a rollback, when the pager reloads information into the cache
** so that the cache is restored to its original state at the start of
** the transaction, for each page restored this routine is called.
**
** This routine needs to reset the extra data section at the end of the
** page to agree with the restored data.
*/
static void pageReinit(void *pData, int pageSize){
  MemPage *pPage = (MemPage*)&((char*)pData)[FORCE_ALIGNMENT(pageSize)];
  if( pPage->isInit ){
    pPage->isInit = 0;
    initPage(pPage, pPage->pParent);
  }
}

/*
** Open a database file.
** 
** zFilename is the name of the database file.  If zFilename is NULL
** a new database with a random name is created.  This randomly named
** database file will be deleted when sqlite3BtreeClose() is called.
*/
int sqlite3BtreeOpen(
  const char *zFilename,  /* Name of the file containing the BTree database */
  Btree **ppBtree,        /* Pointer to new Btree object written here */
  int flags               /* Options */
){
  Btree *pBt;
  int rc;
  int nReserve;
  unsigned char zDbHeader[100];

  /*
  ** The following asserts make sure that structures used by the btree are
  ** the right size.  This is to guard against size changes that result
  ** when compiling on a different architecture.
  */
  assert( sizeof(i64)==8 );
  assert( sizeof(u64)==8 );
  assert( sizeof(u32)==4 );
  assert( sizeof(u16)==2 );
  assert( sizeof(Pgno)==4 );
  assert( sizeof(ptr)==sizeof(char*) );
  assert( sizeof(uptr)==sizeof(ptr) );

  pBt = sqliteMalloc( sizeof(*pBt) );
  if( pBt==0 ){
    *ppBtree = 0;
    return SQLITE_NOMEM;
  }
  rc = sqlite3pager_open(&pBt->pPager, zFilename, EXTRA_SIZE, flags);
  if( rc!=SQLITE_OK ){
    if( pBt->pPager ) sqlite3pager_close(pBt->pPager);
    sqliteFree(pBt);
    *ppBtree = 0;
    return rc;
  }
  sqlite3pager_set_destructor(pBt->pPager, pageDestructor);
  sqlite3pager_set_reiniter(pBt->pPager, pageReinit);
  pBt->pCursor = 0;
  pBt->pPage1 = 0;
  pBt->readOnly = sqlite3pager_isreadonly(pBt->pPager);
  sqlite3pager_read_fileheader(pBt->pPager, sizeof(zDbHeader), zDbHeader);
  pBt->pageSize = get2byte(&zDbHeader[16]);
  if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE ){
    pBt->pageSize = SQLITE_DEFAULT_PAGE_SIZE;
    pBt->maxEmbedFrac = 64;   /* 25% */
    pBt->minEmbedFrac = 32;   /* 12.5% */
    pBt->minLeafFrac = 32;    /* 12.5% */
#ifndef SQLITE_OMIT_AUTOVACUUM
    /* If the magic name ":memory:" will create an in-memory database, then
    ** do not set the auto-vacuum flag, even if SQLITE_DEFAULT_AUTOVACUUM
    ** is true. On the other hand, if SQLITE_OMIT_MEMORYDB has been defined,
    ** then ":memory:" is just a regular file-name. Respect the auto-vacuum
    ** default in this case.
    */
#ifndef SQLITE_OMIT_MEMORYDB
    if( zFilename && strcmp(zFilename,":memory:") ){
#else
    if( zFilename ){
#endif
      pBt->autoVacuum = SQLITE_DEFAULT_AUTOVACUUM;
    }
#endif
    nReserve = 0;
  }else{
    nReserve = zDbHeader[20];
    pBt->maxEmbedFrac = zDbHeader[21];
    pBt->minEmbedFrac = zDbHeader[22];
    pBt->minLeafFrac = zDbHeader[23];
    pBt->pageSizeFixed = 1;
#ifndef SQLITE_OMIT_AUTOVACUUM
    pBt->autoVacuum = (get4byte(&zDbHeader[36 + 4*4])?1:0);
#endif
  }
  pBt->usableSize = pBt->pageSize - nReserve;
  pBt->psAligned = FORCE_ALIGNMENT(pBt->pageSize);
  sqlite3pager_set_pagesize(pBt->pPager, pBt->pageSize);
  *ppBtree = pBt;
  return SQLITE_OK;
}

/*
** Close an open database and invalidate all cursors.
*/
int sqlite3BtreeClose(Btree *pBt){
  while( pBt->pCursor ){
    sqlite3BtreeCloseCursor(pBt->pCursor);
  }
  sqlite3pager_close(pBt->pPager);
  sqliteFree(pBt);
  return SQLITE_OK;
}

/*
** Change the busy handler callback function.
*/
int sqlite3BtreeSetBusyHandler(Btree *pBt, BusyHandler *pHandler){
  sqlite3pager_set_busyhandler(pBt->pPager, pHandler);
  return SQLITE_OK;
}

/*
** Change the limit on the number of pages allowed in the cache.
**
** The maximum number of cache pages is set to the absolute
** value of mxPage.  If mxPage is negative, the pager will
** operate asynchronously - it will not stop to do fsync()s
** to insure data is written to the disk surface before
** continuing.  Transactions still work if synchronous is off,
** and the database cannot be corrupted if this program
** crashes.  But if the operating system crashes or there is
** an abrupt power failure when synchronous is off, the database
** could be left in an inconsistent and unrecoverable state.
** Synchronous is on by default so database corruption is not
** normally a worry.
*/
int sqlite3BtreeSetCacheSize(Btree *pBt, int mxPage){
  sqlite3pager_set_cachesize(pBt->pPager, mxPage);
  return SQLITE_OK;
}

/*
** Change the way data is synced to disk in order to increase or decrease
** how well the database resists damage due to OS crashes and power
** failures.  Level 1 is the same as asynchronous (no syncs() occur and
** there is a high probability of damage)  Level 2 is the default.  There
** is a very low but non-zero probability of damage.  Level 3 reduces the
** probability of damage to near zero but with a write performance reduction.
*/
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
int sqlite3BtreeSetSafetyLevel(Btree *pBt, int level){
  sqlite3pager_set_safety_level(pBt->pPager, level);
  return SQLITE_OK;
}
#endif

#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM)
/*
** Change the default pages size and the number of reserved bytes per page.
**
** The page size must be a power of 2 between 512 and 65536.  If the page
** size supplied does not meet this constraint then the page size is not
** changed.
**
** Page sizes are constrained to be a power of two so that the region
** of the database file used for locking (beginning at PENDING_BYTE,
** the first byte past the 1GB boundary, 0x40000000) needs to occur
** at the beginning of a page.
**
** If parameter nReserve is less than zero, then the number of reserved
** bytes per page is left unchanged.
*/
int sqlite3BtreeSetPageSize(Btree *pBt, int pageSize, int nReserve){
  if( pBt->pageSizeFixed ){
    return SQLITE_READONLY;
  }
  if( nReserve<0 ){
    nReserve = pBt->pageSize - pBt->usableSize;
  }
  if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
        ((pageSize-1)&pageSize)==0 ){
    pBt->pageSize = pageSize;
    pBt->psAligned = FORCE_ALIGNMENT(pageSize);
    sqlite3pager_set_pagesize(pBt->pPager, pageSize);
  }
  pBt->usableSize = pBt->pageSize - nReserve;
  return SQLITE_OK;
}

/*
** Return the currently defined page size
*/
int sqlite3BtreeGetPageSize(Btree *pBt){
  return pBt->pageSize;
}
int sqlite3BtreeGetReserve(Btree *pBt){
  return pBt->pageSize - pBt->usableSize;
}
#endif /* !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM) */

/*
** Change the 'auto-vacuum' property of the database. If the 'autoVacuum'
** parameter is non-zero, then auto-vacuum mode is enabled. If zero, it
** is disabled. The default value for the auto-vacuum property is 
** determined by the SQLITE_DEFAULT_AUTOVACUUM macro.
*/
int sqlite3BtreeSetAutoVacuum(Btree *pBt, int autoVacuum){
#ifdef SQLITE_OMIT_AUTOVACUUM
  return SQLITE_READONLY;
#else
  if( pBt->pageSizeFixed ){
    return SQLITE_READONLY;
  }
  pBt->autoVacuum = (autoVacuum?1:0);
  return SQLITE_OK;
#endif
}

/*
** Return the value of the 'auto-vacuum' property. If auto-vacuum is 
** enabled 1 is returned. Otherwise 0.
*/
int sqlite3BtreeGetAutoVacuum(Btree *pBt){
#ifdef SQLITE_OMIT_AUTOVACUUM
  return 0;
#else
  return pBt->autoVacuum;
#endif
}


/*
** Get a reference to pPage1 of the database file.  This will
** also acquire a readlock on that file.
**
** SQLITE_OK is returned on success.  If the file is not a
** well-formed database file, then SQLITE_CORRUPT is returned.
** SQLITE_BUSY is returned if the database is locked.  SQLITE_NOMEM
** is returned if we run out of memory.  SQLITE_PROTOCOL is returned
** if there is a locking protocol violation.
*/
static int lockBtree(Btree *pBt){
  int rc;
  MemPage *pPage1;
  if( pBt->pPage1 ) return SQLITE_OK;
  rc = getPage(pBt, 1, &pPage1);
  if( rc!=SQLITE_OK ) return rc;
  

  /* Do some checking to help insure the file we opened really is
  ** a valid database file. 
  */
  rc = SQLITE_NOTADB;
  if( sqlite3pager_pagecount(pBt->pPager)>0 ){
    u8 *page1 = pPage1->aData;
    if( memcmp(page1, zMagicHeader, 16)!=0 ){
      goto page1_init_failed;
    }
    if( page1[18]>1 || page1[19]>1 ){
      goto page1_init_failed;
    }
    pBt->pageSize = get2byte(&page1[16]);
    pBt->usableSize = pBt->pageSize - page1[20];
    if( pBt->usableSize<500 ){
      goto page1_init_failed;
    }
    pBt->psAligned = FORCE_ALIGNMENT(pBt->pageSize);
    pBt->maxEmbedFrac = page1[21];
    pBt->minEmbedFrac = page1[22];
    pBt->minLeafFrac = page1[23];
#ifndef SQLITE_OMIT_AUTOVACUUM
    pBt->autoVacuum = (get4byte(&page1[36 + 4*4])?1:0);
#endif
  }

  /* maxLocal is the maximum amount of payload to store locally for
  ** a cell.  Make sure it is small enough so that at least minFanout
  ** cells can will fit on one page.  We assume a 10-byte page header.
  ** Besides the payload, the cell must store:
  **     2-byte pointer to the cell
  **     4-byte child pointer
  **     9-byte nKey value
  **     4-byte nData value
  **     4-byte overflow page pointer
  ** So a cell consists of a 2-byte poiner, a header which is as much as
  ** 17 bytes long, 0 to N bytes of payload, and an optional 4 byte overflow
  ** page pointer.
  */
  pBt->maxLocal = (pBt->usableSize-12)*pBt->maxEmbedFrac/255 - 23;
  pBt->minLocal = (pBt->usableSize-12)*pBt->minEmbedFrac/255 - 23;
  pBt->maxLeaf = pBt->usableSize - 35;
  pBt->minLeaf = (pBt->usableSize-12)*pBt->minLeafFrac/255 - 23;
  if( pBt->minLocal>pBt->maxLocal || pBt->maxLocal<0 ){
    goto page1_init_failed;
  }
  assert( pBt->maxLeaf + 23 <= MX_CELL_SIZE(pBt) );
  pBt->pPage1 = pPage1;
  return SQLITE_OK;

page1_init_failed:
  releasePage(pPage1);
  pBt->pPage1 = 0;
  return rc;
}

/*
** If there are no outstanding cursors and we are not in the middle
** of a transaction but there is a read lock on the database, then
** this routine unrefs the first page of the database file which 
** has the effect of releasing the read lock.
**
** If there are any outstanding cursors, this routine is a no-op.
**
** If there is a transaction in progress, this routine is a no-op.
*/
static void unlockBtreeIfUnused(Btree *pBt){
  if( pBt->inTrans==TRANS_NONE && pBt->pCursor==0 && pBt->pPage1!=0 ){
    if( pBt->pPage1->aData==0 ){
      MemPage *pPage = pBt->pPage1;
      pPage->aData = &((char*)pPage)[-pBt->psAligned];
      pPage->pBt = pBt;
      pPage->pgno = 1;
    }
    releasePage(pBt->pPage1);
    pBt->pPage1 = 0;
    pBt->inStmt = 0;
  }
}

/*
** Create a new database by initializing the first page of the
** file.
*/
static int newDatabase(Btree *pBt){
  MemPage *pP1;
  unsigned char *data;
  int rc;
  if( sqlite3pager_pagecount(pBt->pPager)>0 ) return SQLITE_OK;
  pP1 = pBt->pPage1;
  assert( pP1!=0 );
  data = pP1->aData;
  rc = sqlite3pager_write(data);
  if( rc ) return rc;
  memcpy(data, zMagicHeader, sizeof(zMagicHeader));
  assert( sizeof(zMagicHeader)==16 );
  put2byte(&data[16], pBt->pageSize);
  data[18] = 1;
  data[19] = 1;
  data[20] = pBt->pageSize - pBt->usableSize;
  data[21] = pBt->maxEmbedFrac;
  data[22] = pBt->minEmbedFrac;
  data[23] = pBt->minLeafFrac;
  memset(&data[24], 0, 100-24);
  zeroPage(pP1, PTF_INTKEY|PTF_LEAF|PTF_LEAFDATA );
  pBt->pageSizeFixed = 1;
#ifndef SQLITE_OMIT_AUTOVACUUM
  if( pBt->autoVacuum ){
    put4byte(&data[36 + 4*4], 1);
  }
#endif
  return SQLITE_OK;
}

/*
** Attempt to start a new transaction. A write-transaction
** is started if the second argument is nonzero, otherwise a read-
** transaction.  If the second argument is 2 or more and exclusive
** transaction is started, meaning that no other process is allowed
** to access the database.  A preexisting transaction may not be
** upgrade to exclusive by calling this routine a second time - the
** exclusivity flag only works for a new transaction.
**
** A write-transaction must be started before attempting any 
** changes to the database.  None of the following routines 
** will work unless a transaction is started first:
**
**      sqlite3BtreeCreateTable()
**      sqlite3BtreeCreateIndex()
**      sqlite3BtreeClearTable()
**      sqlite3BtreeDropTable()
**      sqlite3BtreeInsert()
**      sqlite3BtreeDelete()
**      sqlite3BtreeUpdateMeta()
**
** If wrflag is true, then nMaster specifies the maximum length of
** a master journal file name supplied later via sqlite3BtreeSync().
** This is so that appropriate space can be allocated in the journal file
** when it is created..
*/
int sqlite3BtreeBeginTrans(Btree *pBt, int wrflag){
  int rc = SQLITE_OK;

  /* If the btree is already in a write-transaction, or it
  ** is already in a read-transaction and a read-transaction
  ** is requested, this is a no-op.
  */
  if( pBt->inTrans==TRANS_WRITE || 
      (pBt->inTrans==TRANS_READ && !wrflag) ){
    return SQLITE_OK;
  }
  if( pBt->readOnly && wrflag ){
    return SQLITE_READONLY;
  }

  if( pBt->pPage1==0 ){
    rc = lockBtree(pBt);
  }

  if( rc==SQLITE_OK && wrflag ){
    rc = sqlite3pager_begin(pBt->pPage1->aData, wrflag>1);
    if( rc==SQLITE_OK ){
      rc = newDatabase(pBt);
    }
  }

  if( rc==SQLITE_OK ){
    pBt->inTrans = (wrflag?TRANS_WRITE:TRANS_READ);
    if( wrflag ) pBt->inStmt = 0;
  }else{
    unlockBtreeIfUnused(pBt);
  }
  return rc;
}

#ifndef SQLITE_OMIT_AUTOVACUUM

/*
** Set the pointer-map entries for all children of page pPage. Also, if
** pPage contains cells that point to overflow pages, set the pointer
** map entries for the overflow pages as well.
*/
static int setChildPtrmaps(MemPage *pPage){
  int i;                             /* Counter variable */
  int nCell;                         /* Number of cells in page pPage */
  int rc = SQLITE_OK;                /* Return code */
  Btree *pBt = pPage->pBt;
  int isInitOrig = pPage->isInit;
  Pgno pgno = pPage->pgno;

  initPage(pPage, 0);
  nCell = pPage->nCell;

  for(i=0; i<nCell; i++){
    u8 *pCell = findCell(pPage, i);

    rc = ptrmapPutOvflPtr(pPage, pCell);
    if( rc!=SQLITE_OK ){
      goto set_child_ptrmaps_out;
    }

    if( !pPage->leaf ){
      Pgno childPgno = get4byte(pCell);
      rc = ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno);
      if( rc!=SQLITE_OK ) goto set_child_ptrmaps_out;
    }
  }

  if( !pPage->leaf ){
    Pgno childPgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
    rc = ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno);
  }

set_child_ptrmaps_out:
  pPage->isInit = isInitOrig;
  return rc;
}

/*
** Somewhere on pPage, which is guarenteed to be a btree page, not an overflow
** page, is a pointer to page iFrom. Modify this pointer so that it points to
** iTo. Parameter eType describes the type of pointer to be modified, as 
** follows:
**
** PTRMAP_BTREE:     pPage is a btree-page. The pointer points at a child 
**                   page of pPage.
**
** PTRMAP_OVERFLOW1: pPage is a btree-page. The pointer points at an overflow
**                   page pointed to by one of the cells on pPage.
**
** PTRMAP_OVERFLOW2: pPage is an overflow-page. The pointer points at the next
**                   overflow page in the list.
*/
static int modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
  if( eType==PTRMAP_OVERFLOW2 ){
    /* The pointer is always the first 4 bytes of the page in this case.  */
    if( get4byte(pPage->aData)!=iFrom ){
      return SQLITE_CORRUPT;
    }
    put4byte(pPage->aData, iTo);
  }else{
    int isInitOrig = pPage->isInit;
    int i;
    int nCell;

    initPage(pPage, 0);
    nCell = pPage->nCell;

    for(i=0; i<nCell; i++){
      u8 *pCell = findCell(pPage, i);
      if( eType==PTRMAP_OVERFLOW1 ){
        CellInfo info;
        parseCellPtr(pPage, pCell, &info);
        if( info.iOverflow ){
          if( iFrom==get4byte(&pCell[info.iOverflow]) ){
            put4byte(&pCell[info.iOverflow], iTo);
            break;
          }
        }
      }else{
        if( get4byte(pCell)==iFrom ){
          put4byte(pCell, iTo);
          break;
        }
      }
    }
  
    if( i==nCell ){
      if( eType!=PTRMAP_BTREE || 
          get4byte(&pPage->aData[pPage->hdrOffset+8])!=iFrom ){
        return SQLITE_CORRUPT;
      }
      put4byte(&pPage->aData[pPage->hdrOffset+8], iTo);
    }

    pPage->isInit = isInitOrig;
  }
  return SQLITE_OK;
}


/*
** Move the open database page pDbPage to location iFreePage in the 
** database. The pDbPage reference remains valid.
*/
static int relocatePage(
  Btree *pBt,              /* Btree */
  MemPage *pDbPage,        /* Open page to move */
  u8 eType,                /* Pointer map 'type' entry for pDbPage */
  Pgno iPtrPage,           /* Pointer map 'page-no' entry for pDbPage */
  Pgno iFreePage           /* The location to move pDbPage to */
){
  MemPage *pPtrPage;   /* The page that contains a pointer to pDbPage */
  Pgno iDbPage = pDbPage->pgno;
  Pager *pPager = pBt->pPager;
  int rc;

  assert( eType==PTRMAP_OVERFLOW2 || eType==PTRMAP_OVERFLOW1 || 
      eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE );

  /* Move page iDbPage from it's current location to page number iFreePage */
  TRACE(("AUTOVACUUM: Moving %d to free page %d (ptr page %d type %d)\n", 
      iDbPage, iFreePage, iPtrPage, eType));
  rc = sqlite3pager_movepage(pPager, pDbPage->aData, iFreePage);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  pDbPage->pgno = iFreePage;

  /* If pDbPage was a btree-page, then it may have child pages and/or cells
  ** that point to overflow pages. The pointer map entries for all these
  ** pages need to be changed.
  **
  ** If pDbPage is an overflow page, then the first 4 bytes may store a
  ** pointer to a subsequent overflow page. If this is the case, then
  ** the pointer map needs to be updated for the subsequent overflow page.
  */
  if( eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE ){
    rc = setChildPtrmaps(pDbPage);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }else{
    Pgno nextOvfl = get4byte(pDbPage->aData);
    if( nextOvfl!=0 ){
      rc = ptrmapPut(pBt, nextOvfl, PTRMAP_OVERFLOW2, iFreePage);
      if( rc!=SQLITE_OK ){
        return rc;
      }
    }
  }

  /* Fix the database pointer on page iPtrPage that pointed at iDbPage so
  ** that it points at iFreePage. Also fix the pointer map entry for
  ** iPtrPage.
  */
  if( eType!=PTRMAP_ROOTPAGE ){
    rc = getPage(pBt, iPtrPage, &pPtrPage);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    rc = sqlite3pager_write(pPtrPage->aData);
    if( rc!=SQLITE_OK ){
      releasePage(pPtrPage);
      return rc;
    }
    rc = modifyPagePointer(pPtrPage, iDbPage, iFreePage, eType);
    releasePage(pPtrPage);
    if( rc==SQLITE_OK ){
      rc = ptrmapPut(pBt, iFreePage, eType, iPtrPage);
    }
  }
  return rc;
}

/* Forward declaration required by autoVacuumCommit(). */
static int allocatePage(Btree *, MemPage **, Pgno *, Pgno, u8);

/*
** This routine is called prior to sqlite3pager_commit when a transaction
** is commited for an auto-vacuum database.
*/
static int autoVacuumCommit(Btree *pBt, Pgno *nTrunc){
  Pager *pPager = pBt->pPager;
  Pgno nFreeList;   /* Number of pages remaining on the free-list. */
  int nPtrMap;      /* Number of pointer-map pages deallocated */
  Pgno origSize;  /* Pages in the database file */
  Pgno finSize;   /* Pages in the database file after truncation */
  int rc;           /* Return code */
  u8 eType;
  int pgsz = pBt->pageSize;  /* Page size for this database */
  Pgno iDbPage;              /* The database page to move */
  MemPage *pDbMemPage = 0;   /* "" */
  Pgno iPtrPage;             /* The page that contains a pointer to iDbPage */
  Pgno iFreePage;            /* The free-list page to move iDbPage to */
  MemPage *pFreeMemPage = 0; /* "" */

#ifndef NDEBUG
  int nRef = *sqlite3pager_stats(pPager);
#endif

  assert( pBt->autoVacuum );
  if( PTRMAP_ISPAGE(pgsz, sqlite3pager_pagecount(pPager)) ){
    return SQLITE_CORRUPT;
  }

  /* Figure out how many free-pages are in the database. If there are no
  ** free pages, then auto-vacuum is a no-op.
  */
  nFreeList = get4byte(&pBt->pPage1->aData[36]);
  if( nFreeList==0 ){
    *nTrunc = 0;
    return SQLITE_OK;
  }

  origSize = sqlite3pager_pagecount(pPager);
  nPtrMap = (nFreeList-origSize+PTRMAP_PAGENO(pgsz, origSize)+pgsz/5)/(pgsz/5);
  finSize = origSize - nFreeList - nPtrMap;
  if( origSize>PENDING_BYTE_PAGE(pBt) && finSize<=PENDING_BYTE_PAGE(pBt) ){
    finSize--;
    if( PTRMAP_ISPAGE(pBt->usableSize, finSize) ){
      finSize--;
    }
  }
  TRACE(("AUTOVACUUM: Begin (db size %d->%d)\n", origSize, finSize));

  /* Variable 'finSize' will be the size of the file in pages after
  ** the auto-vacuum has completed (the current file size minus the number
  ** of pages on the free list). Loop through the pages that lie beyond
  ** this mark, and if they are not already on the free list, move them
  ** to a free page earlier in the file (somewhere before finSize).
  */
  for( iDbPage=finSize+1; iDbPage<=origSize; iDbPage++ ){
    /* If iDbPage is a pointer map page, or the pending-byte page, skip it. */
    if( PTRMAP_ISPAGE(pgsz, iDbPage) || iDbPage==PENDING_BYTE_PAGE(pBt) ){
      continue;
    }

    rc = ptrmapGet(pBt, iDbPage, &eType, &iPtrPage);
    if( rc!=SQLITE_OK ) goto autovacuum_out;
    assert( eType!=PTRMAP_ROOTPAGE );

    /* If iDbPage is free, do not swap it.  */
    if( eType==PTRMAP_FREEPAGE ){
      continue;
    }
    rc = getPage(pBt, iDbPage, &pDbMemPage);
    if( rc!=SQLITE_OK ) goto autovacuum_out;

    /* Find the next page in the free-list that is not already at the end 
    ** of the file. A page can be pulled off the free list using the 
    ** allocatePage() routine.
    */
    do{
      if( pFreeMemPage ){
        releasePage(pFreeMemPage);
        pFreeMemPage = 0;
      }
      rc = allocatePage(pBt, &pFreeMemPage, &iFreePage, 0, 0);
      if( rc!=SQLITE_OK ){
        releasePage(pDbMemPage);
        goto autovacuum_out;
      }
      assert( iFreePage<=origSize );
    }while( iFreePage>finSize );
    releasePage(pFreeMemPage);
    pFreeMemPage = 0;

    rc = relocatePage(pBt, pDbMemPage, eType, iPtrPage, iFreePage);
    releasePage(pDbMemPage);
    if( rc!=SQLITE_OK ) goto autovacuum_out;
  }

  /* The entire free-list has been swapped to the end of the file. So
  ** truncate the database file to finSize pages and consider the
  ** free-list empty.
  */
  rc = sqlite3pager_write(pBt->pPage1->aData);
  if( rc!=SQLITE_OK ) goto autovacuum_out;
  put4byte(&pBt->pPage1->aData[32], 0);
  put4byte(&pBt->pPage1->aData[36], 0);
  if( rc!=SQLITE_OK ) goto autovacuum_out;
  *nTrunc = finSize;

autovacuum_out:
  assert( nRef==*sqlite3pager_stats(pPager) );
  if( rc!=SQLITE_OK ){
    sqlite3pager_rollback(pPager);
  }
  return rc;
}
#endif

/*
** Commit the transaction currently in progress.
**
** This will release the write lock on the database file.  If there
** are no active cursors, it also releases the read lock.
*/
int sqlite3BtreeCommit(Btree *pBt){
  int rc = SQLITE_OK;
  if( pBt->inTrans==TRANS_WRITE ){
    rc = sqlite3pager_commit(pBt->pPager);
  }
  pBt->inTrans = TRANS_NONE;
  pBt->inStmt = 0;
  unlockBtreeIfUnused(pBt);
  return rc;
}

#ifndef NDEBUG
/*
** Return the number of write-cursors open on this handle. This is for use
** in assert() expressions, so it is only compiled if NDEBUG is not
** defined.
*/
static int countWriteCursors(Btree *pBt){
  BtCursor *pCur;
  int r = 0;
  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
    if( pCur->wrFlag ) r++;
  }
  return r;
}
#endif

#ifdef SQLITE_TEST
/*
** Print debugging information about all cursors to standard output.
*/
void sqlite3BtreeCursorList(Btree *pBt){
  BtCursor *pCur;
  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
    MemPage *pPage = pCur->pPage;
    char *zMode = pCur->wrFlag ? "rw" : "ro";
    sqlite3DebugPrintf("CURSOR %p rooted at %4d(%s) currently at %d.%d%s\n",
       pCur, pCur->pgnoRoot, zMode,
       pPage ? pPage->pgno : 0, pCur->idx,
       pCur->isValid ? "" : " eof"
    );
  }
}
#endif

/*
** Rollback the transaction in progress.  All cursors will be
** invalided by this operation.  Any attempt to use a cursor
** that was open at the beginning of this operation will result
** in an error.
**
** This will release the write lock on the database file.  If there
** are no active cursors, it also releases the read lock.
*/
int sqlite3BtreeRollback(Btree *pBt){
  int rc = SQLITE_OK;
  MemPage *pPage1;
  if( pBt->inTrans==TRANS_WRITE ){
    rc = sqlite3pager_rollback(pBt->pPager);
    /* The rollback may have destroyed the pPage1->aData value.  So
    ** call getPage() on page 1 again to make sure pPage1->aData is
    ** set correctly. */
    if( getPage(pBt, 1, &pPage1)==SQLITE_OK ){
      releasePage(pPage1);
    }
    assert( countWriteCursors(pBt)==0 );
  }
  pBt->inTrans = TRANS_NONE;
  pBt->inStmt = 0;
  unlockBtreeIfUnused(pBt);
  return rc;
}

/*
** Start a statement subtransaction.  The subtransaction can
** can be rolled back independently of the main transaction.
** You must start a transaction before starting a subtransaction.
** The subtransaction is ended automatically if the main transaction
** commits or rolls back.
**
** Only one subtransaction may be active at a time.  It is an error to try
** to start a new subtransaction if another subtransaction is already active.
**
** Statement subtransactions are used around individual SQL statements
** that are contained within a BEGIN...COMMIT block.  If a constraint
** error occurs within the statement, the effect of that one statement
** can be rolled back without having to rollback the entire transaction.
*/
int sqlite3BtreeBeginStmt(Btree *pBt){
  int rc;
  if( (pBt->inTrans!=TRANS_WRITE) || pBt->inStmt ){
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }
  rc = pBt->readOnly ? SQLITE_OK : sqlite3pager_stmt_begin(pBt->pPager);
  pBt->inStmt = 1;
  return rc;
}


/*
** Commit the statment subtransaction currently in progress.  If no
** subtransaction is active, this is a no-op.
*/
int sqlite3BtreeCommitStmt(Btree *pBt){
  int rc;
  if( pBt->inStmt && !pBt->readOnly ){
    rc = sqlite3pager_stmt_commit(pBt->pPager);
  }else{
    rc = SQLITE_OK;
  }
  pBt->inStmt = 0;
  return rc;
}

/*
** Rollback the active statement subtransaction.  If no subtransaction
** is active this routine is a no-op.
**
** All cursors will be invalidated by this operation.  Any attempt
** to use a cursor that was open at the beginning of this operation
** will result in an error.
*/
int sqlite3BtreeRollbackStmt(Btree *pBt){
  int rc;
  if( pBt->inStmt==0 || pBt->readOnly ) return SQLITE_OK;
  rc = sqlite3pager_stmt_rollback(pBt->pPager);
  assert( countWriteCursors(pBt)==0 );
  pBt->inStmt = 0;
  return rc;
}

/*
** Default key comparison function to be used if no comparison function
** is specified on the sqlite3BtreeCursor() call.
*/
static int dfltCompare(
  void *NotUsed,             /* User data is not used */
  int n1, const void *p1,    /* First key to compare */
  int n2, const void *p2     /* Second key to compare */
){
  int c;
  c = memcmp(p1, p2, n1<n2 ? n1 : n2);
  if( c==0 ){
    c = n1 - n2;
  }
  return c;
}

/*
** Create a new cursor for the BTree whose root is on the page
** iTable.  The act of acquiring a cursor gets a read lock on 
** the database file.
**
** If wrFlag==0, then the cursor can only be used for reading.
** If wrFlag==1, then the cursor can be used for reading or for
** writing if other conditions for writing are also met.  These
** are the conditions that must be met in order for writing to
** be allowed:
**
** 1:  The cursor must have been opened with wrFlag==1
**
** 2:  No other cursors may be open with wrFlag==0 on the same table
**
** 3:  The database must be writable (not on read-only media)
**
** 4:  There must be an active transaction.
**
** Condition 2 warrants further discussion.  If any cursor is opened
** on a table with wrFlag==0, that prevents all other cursors from
** writing to that table.  This is a kind of "read-lock".  When a cursor
** is opened with wrFlag==0 it is guaranteed that the table will not
** change as long as the cursor is open.  This allows the cursor to
** do a sequential scan of the table without having to worry about
** entries being inserted or deleted during the scan.  Cursors should
** be opened with wrFlag==0 only if this read-lock property is needed.
** That is to say, cursors should be opened with wrFlag==0 only if they
** intend to use the sqlite3BtreeNext() system call.  All other cursors
** should be opened with wrFlag==1 even if they never really intend
** to write.
** 
** No checking is done to make sure that page iTable really is the
** root page of a b-tree.  If it is not, then the cursor acquired
** will not work correctly.
**
** The comparison function must be logically the same for every cursor
** on a particular table.  Changing the comparison function will result
** in incorrect operations.  If the comparison function is NULL, a
** default comparison function is used.  The comparison function is
** always ignored for INTKEY tables.
*/
int sqlite3BtreeCursor(
  Btree *pBt,                                 /* The btree */
  int iTable,                                 /* Root page of table to open */
  int wrFlag,                                 /* 1 to write. 0 read-only */
  int (*xCmp)(void*,int,const void*,int,const void*), /* Key Comparison func */
  void *pArg,                                 /* First arg to xCompare() */
  BtCursor **ppCur                            /* Write new cursor here */
){
  int rc;
  BtCursor *pCur;

  *ppCur = 0;
  if( wrFlag ){
    if( pBt->readOnly ){
      return SQLITE_READONLY;
    }
    if( checkReadLocks(pBt, iTable, 0) ){
      return SQLITE_LOCKED;
    }
  }
  if( pBt->pPage1==0 ){
    rc = lockBtree(pBt);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }
  pCur = sqliteMallocRaw( sizeof(*pCur) );
  if( pCur==0 ){
    rc = SQLITE_NOMEM;
    goto create_cursor_exception;
  }
  pCur->pgnoRoot = (Pgno)iTable;
  if( iTable==1 && sqlite3pager_pagecount(pBt->pPager)==0 ){
    rc = SQLITE_EMPTY;
    pCur->pPage = 0;
    goto create_cursor_exception;
  }
  pCur->pPage = 0;  /* For exit-handler, in case getAndInitPage() fails. */
  rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->pPage, 0);
  if( rc!=SQLITE_OK ){
    goto create_cursor_exception;
  }
  pCur->xCompare = xCmp ? xCmp : dfltCompare;
  pCur->pArg = pArg;
  pCur->pBt = pBt;
  pCur->wrFlag = wrFlag;
  pCur->idx = 0;
  memset(&pCur->info, 0, sizeof(pCur->info));
  pCur->pNext = pBt->pCursor;
  if( pCur->pNext ){
    pCur->pNext->pPrev = pCur;
  }
  pCur->pPrev = 0;
  pBt->pCursor = pCur;
  pCur->isValid = 0;
  *ppCur = pCur;
  return SQLITE_OK;

create_cursor_exception:
  if( pCur ){
    releasePage(pCur->pPage);
    sqliteFree(pCur);
  }
  unlockBtreeIfUnused(pBt);
  return rc;
}

#if 0  /* Not Used */
/*
** Change the value of the comparison function used by a cursor.
*/
void sqlite3BtreeSetCompare(
  BtCursor *pCur,     /* The cursor to whose comparison function is changed */
  int(*xCmp)(void*,int,const void*,int,const void*), /* New comparison func */
  void *pArg          /* First argument to xCmp() */
){
  pCur->xCompare = xCmp ? xCmp : dfltCompare;
  pCur->pArg = pArg;
}
#endif

/*
** Close a cursor.  The read lock on the database file is released
** when the last cursor is closed.
*/
int sqlite3BtreeCloseCursor(BtCursor *pCur){
  Btree *pBt = pCur->pBt;
  if( pCur->pPrev ){
    pCur->pPrev->pNext = pCur->pNext;
  }else{
    pBt->pCursor = pCur->pNext;
  }
  if( pCur->pNext ){
    pCur->pNext->pPrev = pCur->pPrev;
  }
  releasePage(pCur->pPage);
  unlockBtreeIfUnused(pBt);
  sqliteFree(pCur);
  return SQLITE_OK;
}

/*
** Make a temporary cursor by filling in the fields of pTempCur.
** The temporary cursor is not on the cursor list for the Btree.
*/
static void getTempCursor(BtCursor *pCur, BtCursor *pTempCur){
  memcpy(pTempCur, pCur, sizeof(*pCur));
  pTempCur->pNext = 0;
  pTempCur->pPrev = 0;
  if( pTempCur->pPage ){
    sqlite3pager_ref(pTempCur->pPage->aData);
  }
}

/*
** Delete a temporary cursor such as was made by the CreateTemporaryCursor()
** function above.
*/
static void releaseTempCursor(BtCursor *pCur){
  if( pCur->pPage ){
    sqlite3pager_unref(pCur->pPage->aData);
  }
}

/*
** Make sure the BtCursor.info field of the given cursor is valid.
** If it is not already valid, call parseCell() to fill it in.
**
** BtCursor.info is a cache of the information in the current cell.
** Using this cache reduces the number of calls to parseCell().
*/
static void getCellInfo(BtCursor *pCur){
  if( pCur->info.nSize==0 ){
    parseCell(pCur->pPage, pCur->idx, &pCur->info);
  }else{
#ifndef NDEBUG
    CellInfo info;
    memset(&info, 0, sizeof(info));
    parseCell(pCur->pPage, pCur->idx, &info);
    assert( memcmp(&info, &pCur->info, sizeof(info))==0 );
#endif
  }
}

/*
** Set *pSize to the size of the buffer needed to hold the value of
** the key for the current entry.  If the cursor is not pointing
** to a valid entry, *pSize is set to 0. 
**
** For a table with the INTKEY flag set, this routine returns the key
** itself, not the number of bytes in the key.
*/
int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
  if( !pCur->isValid ){
    *pSize = 0;
  }else{
    getCellInfo(pCur);
    *pSize = pCur->info.nKey;
  }
  return SQLITE_OK;
}

/*
** Set *pSize to the number of bytes of data in the entry the
** cursor currently points to.  Always return SQLITE_OK.
** Failure is not possible.  If the cursor is not currently
** pointing to an entry (which can happen, for example, if
** the database is empty) then *pSize is set to 0.
*/
int sqlite3BtreeDataSize(BtCursor *pCur, u32 *pSize){
  if( !pCur->isValid ){
    /* Not pointing at a valid entry - set *pSize to 0. */
    *pSize = 0;
  }else{
    getCellInfo(pCur);
    *pSize = pCur->info.nData;
  }
  return SQLITE_OK;
}

/*
** Read payload information from the entry that the pCur cursor is
** pointing to.  Begin reading the payload at "offset" and read
** a total of "amt" bytes.  Put the result in zBuf.
**
** This routine does not make a distinction between key and data.
** It just reads bytes from the payload area.  Data might appear
** on the main page or be scattered out on multiple overflow pages.
*/
static int getPayload(
  BtCursor *pCur,      /* Cursor pointing to entry to read from */
  int offset,          /* Begin reading this far into payload */
  int amt,             /* Read this many bytes */
  unsigned char *pBuf, /* Write the bytes into this buffer */ 
  int skipKey          /* offset begins at data if this is true */
){
  unsigned char *aPayload;
  Pgno nextPage;
  int rc;
  MemPage *pPage;
  Btree *pBt;
  int ovflSize;
  u32 nKey;

  assert( pCur!=0 && pCur->pPage!=0 );
  assert( pCur->isValid );
  pBt = pCur->pBt;
  pPage = pCur->pPage;
  pageIntegrity(pPage);
  assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
  getCellInfo(pCur);
  aPayload = pCur->info.pCell;
  aPayload += pCur->info.nHeader;
  if( pPage->intKey ){
    nKey = 0;
  }else{
    nKey = pCur->info.nKey;
  }
  assert( offset>=0 );
  if( skipKey ){
    offset += nKey;
  }
  if( offset+amt > nKey+pCur->info.nData ){
    return SQLITE_ERROR;
  }
  if( offset<pCur->info.nLocal ){
    int a = amt;
    if( a+offset>pCur->info.nLocal ){
      a = pCur->info.nLocal - offset;
    }
    memcpy(pBuf, &aPayload[offset], a);
    if( a==amt ){
      return SQLITE_OK;
    }
    offset = 0;
    pBuf += a;
    amt -= a;
  }else{
    offset -= pCur->info.nLocal;
  }
  ovflSize = pBt->usableSize - 4;
  if( amt>0 ){
    nextPage = get4byte(&aPayload[pCur->info.nLocal]);
    while( amt>0 && nextPage ){
      rc = sqlite3pager_get(pBt->pPager, nextPage, (void**)&aPayload);
      if( rc!=0 ){
        return rc;
      }
      nextPage = get4byte(aPayload);
      if( offset<ovflSize ){
        int a = amt;
        if( a + offset > ovflSize ){
          a = ovflSize - offset;
        }
        memcpy(pBuf, &aPayload[offset+4], a);
        offset = 0;
        amt -= a;
        pBuf += a;
      }else{
        offset -= ovflSize;
      }
      sqlite3pager_unref(aPayload);
    }
  }

  if( amt>0 ){
    return SQLITE_CORRUPT; /* bkpt-CORRUPT */
  }
  return SQLITE_OK;
}

/*
** Read part of the key associated with cursor pCur.  Exactly
** "amt" bytes will be transfered into pBuf[].  The transfer
** begins at "offset".
**
** Return SQLITE_OK on success or an error code if anything goes
** wrong.  An error is returned if "offset+amt" is larger than
** the available payload.
*/
int sqlite3BtreeKey(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
  assert( pCur->isValid );
  assert( pCur->pPage!=0 );
  assert( pCur->pPage->intKey==0 );
  assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell );
  return getPayload(pCur, offset, amt, (unsigned char*)pBuf, 0);
}

/*
** Read part of the data associated with cursor pCur.  Exactly
** "amt" bytes will be transfered into pBuf[].  The transfer
** begins at "offset".
**
** Return SQLITE_OK on success or an error code if anything goes
** wrong.  An error is returned if "offset+amt" is larger than
** the available payload.
*/
int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
  assert( pCur->isValid );
  assert( pCur->pPage!=0 );
  assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell );
  return getPayload(pCur, offset, amt, pBuf, 1);
}

/*
** Return a pointer to payload information from the entry that the 
** pCur cursor is pointing to.  The pointer is to the beginning of
** the key if skipKey==0 and it points to the beginning of data if
** skipKey==1.  The number of bytes of available key/data is written
** into *pAmt.  If *pAmt==0, then the value returned will not be
** a valid pointer.
**
** This routine is an optimization.  It is common for the entire key
** and data to fit on the local page and for there to be no overflow
** pages.  When that is so, this routine can be used to access the
** key and data without making a copy.  If the key and/or data spills
** onto overflow pages, then getPayload() must be used to reassembly
** the key/data and copy it into a preallocated buffer.
**
** The pointer returned by this routine looks directly into the cached
** page of the database.  The data might change or move the next time
** any btree routine is called.
*/
static const unsigned char *fetchPayload(
  BtCursor *pCur,      /* Cursor pointing to entry to read from */
  int *pAmt,           /* Write the number of available bytes here */
  int skipKey          /* read beginning at data if this is true */
){
  unsigned char *aPayload;
  MemPage *pPage;
  Btree *pBt;
  u32 nKey;
  int nLocal;

  assert( pCur!=0 && pCur->pPage!=0 );
  assert( pCur->isValid );
  pBt = pCur->pBt;
  pPage = pCur->pPage;
  pageIntegrity(pPage);
  assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
  getCellInfo(pCur);
  aPayload = pCur->info.pCell;
  aPayload += pCur->info.nHeader;
  if( pPage->intKey ){
    nKey = 0;
  }else{
    nKey = pCur->info.nKey;
  }
  if( skipKey ){
    aPayload += nKey;
    nLocal = pCur->info.nLocal - nKey;
  }else{
    nLocal = pCur->info.nLocal;
    if( nLocal>nKey ){
      nLocal = nKey;
    }
  }
  *pAmt = nLocal;
  return aPayload;
}


/*
** For the entry that cursor pCur is point to, return as
** many bytes of the key or data as are available on the local
** b-tree page.  Write the number of available bytes into *pAmt.
**
** The pointer returned is ephemeral.  The key/data may move
** or be destroyed on the next call to any Btree routine.
**
** These routines is used to get quick access to key and data
** in the common case where no overflow pages are used.
*/
const void *sqlite3BtreeKeyFetch(BtCursor *pCur, int *pAmt){
  return (const void*)fetchPayload(pCur, pAmt, 0);
}
const void *sqlite3BtreeDataFetch(BtCursor *pCur, int *pAmt){
  return (const void*)fetchPayload(pCur, pAmt, 1);
}


/*
** Move the cursor down to a new child page.  The newPgno argument is the
** page number of the child page to move to.
*/
static int moveToChild(BtCursor *pCur, u32 newPgno){
  int rc;
  MemPage *pNewPage;
  MemPage *pOldPage;
  Btree *pBt = pCur->pBt;

  assert( pCur->isValid );
  rc = getAndInitPage(pBt, newPgno, &pNewPage, pCur->pPage);
  if( rc ) return rc;
  pageIntegrity(pNewPage);
  pNewPage->idxParent = pCur->idx;
  pOldPage = pCur->pPage;
  pOldPage->idxShift = 0;
  releasePage(pOldPage);
  pCur->pPage = pNewPage;
  pCur->idx = 0;
  pCur->info.nSize = 0;
  if( pNewPage->nCell<1 ){
    return SQLITE_CORRUPT; /* bkpt-CORRUPT */
  }
  return SQLITE_OK;
}

/*
** Return true if the page is the virtual root of its table.
**
** The virtual root page is the root page for most tables.  But
** for the table rooted on page 1, sometime the real root page
** is empty except for the right-pointer.  In such cases the
** virtual root page is the page that the right-pointer of page
** 1 is pointing to.
*/
static int isRootPage(MemPage *pPage){
  MemPage *pParent = pPage->pParent;
  if( pParent==0 ) return 1;
  if( pParent->pgno>1 ) return 0;
  if( get2byte(&pParent->aData[pParent->hdrOffset+3])==0 ) return 1;
  return 0;
}

/*
** Move the cursor up to the parent page.
**
** pCur->idx is set to the cell index that contains the pointer
** to the page we are coming from.  If we are coming from the
** right-most child page then pCur->idx is set to one more than
** the largest cell index.
*/
static void moveToParent(BtCursor *pCur){
  Pgno oldPgno;
  MemPage *pParent;
  MemPage *pPage;
  int idxParent;

  assert( pCur->isValid );
  pPage = pCur->pPage;
  assert( pPage!=0 );
  assert( !isRootPage(pPage) );
  pageIntegrity(pPage);
  pParent = pPage->pParent;
  assert( pParent!=0 );
  pageIntegrity(pParent);
  idxParent = pPage->idxParent;
  sqlite3pager_ref(pParent->aData);
  oldPgno = pPage->pgno;
  releasePage(pPage);
  pCur->pPage = pParent;
  pCur->info.nSize = 0;
  assert( pParent->idxShift==0 );
  pCur->idx = idxParent;
}

/*
** Move the cursor to the root page
*/
static int moveToRoot(BtCursor *pCur){
  MemPage *pRoot;
  int rc;
  Btree *pBt = pCur->pBt;

  rc = getAndInitPage(pBt, pCur->pgnoRoot, &pRoot, 0);
  if( rc ){
    pCur->isValid = 0;
    return rc;
  }
  releasePage(pCur->pPage);
  pageIntegrity(pRoot);
  pCur->pPage = pRoot;
  pCur->idx = 0;
  pCur->info.nSize = 0;
  if( pRoot->nCell==0 && !pRoot->leaf ){
    Pgno subpage;
    assert( pRoot->pgno==1 );
    subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);
    assert( subpage>0 );
    pCur->isValid = 1;
    rc = moveToChild(pCur, subpage);
  }
  pCur->isValid = pCur->pPage->nCell>0;
  return rc;
}

/*
** Move the cursor down to the left-most leaf entry beneath the
** entry to which it is currently pointing.
*/
static int moveToLeftmost(BtCursor *pCur){
  Pgno pgno;
  int rc;
  MemPage *pPage;

  assert( pCur->isValid );
  while( !(pPage = pCur->pPage)->leaf ){
    assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
    pgno = get4byte(findCell(pPage, pCur->idx));
    rc = moveToChild(pCur, pgno);
    if( rc ) return rc;
  }
  return SQLITE_OK;
}

/*
** Move the cursor down to the right-most leaf entry beneath the
** page to which it is currently pointing.  Notice the difference
** between moveToLeftmost() and moveToRightmost().  moveToLeftmost()
** finds the left-most entry beneath the *entry* whereas moveToRightmost()
** finds the right-most entry beneath the *page*.
*/
static int moveToRightmost(BtCursor *pCur){
  Pgno pgno;
  int rc;
  MemPage *pPage;

  assert( pCur->isValid );
  while( !(pPage = pCur->pPage)->leaf ){
    pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
    pCur->idx = pPage->nCell;
    rc = moveToChild(pCur, pgno);
    if( rc ) return rc;
  }
  pCur->idx = pPage->nCell - 1;
  pCur->info.nSize = 0;
  return SQLITE_OK;
}

/* Move the cursor to the first entry in the table.  Return SQLITE_OK
** on success.  Set *pRes to 0 if the cursor actually points to something
** or set *pRes to 1 if the table is empty.
*/
int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
  int rc;
  rc = moveToRoot(pCur);
  if( rc ) return rc;
  if( pCur->isValid==0 ){
    assert( pCur->pPage->nCell==0 );
    *pRes = 1;
    return SQLITE_OK;
  }
  assert( pCur->pPage->nCell>0 );
  *pRes = 0;
  rc = moveToLeftmost(pCur);
  return rc;
}

/* Move the cursor to the last entry in the table.  Return SQLITE_OK
** on success.  Set *pRes to 0 if the cursor actually points to something
** or set *pRes to 1 if the table is empty.
*/
int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
  int rc;
  rc = moveToRoot(pCur);
  if( rc ) return rc;
  if( pCur->isValid==0 ){
    assert( pCur->pPage->nCell==0 );
    *pRes = 1;
    return SQLITE_OK;
  }
  assert( pCur->isValid );
  *pRes = 0;
  rc = moveToRightmost(pCur);
  return rc;
}

/* Move the cursor so that it points to an entry near pKey/nKey.
** Return a success code.
**
** For INTKEY tables, only the nKey parameter is used.  pKey is
** ignored.  For other tables, nKey is the number of bytes of data
** in nKey.  The comparison function specified when the cursor was
** created is used to compare keys.
**
** If an exact match is not found, then the cursor is always
** left pointing at a leaf page which would hold the entry if it
** were present.  The cursor might point to an entry that comes
** before or after the key.
**
** The result of comparing the key with the entry to which the
** cursor is written to *pRes if pRes!=NULL.  The meaning of
** this value is as follows:
**
**     *pRes<0      The cursor is left pointing at an entry that
**                  is smaller than pKey or if the table is empty
**                  and the cursor is therefore left point to nothing.
**
**     *pRes==0     The cursor is left pointing at an entry that
**                  exactly matches pKey.
**
**     *pRes>0      The cursor is left pointing at an entry that
**                  is larger than pKey.
*/
int sqlite3BtreeMoveto(BtCursor *pCur, const void *pKey, i64 nKey, int *pRes){
  int rc;
  rc = moveToRoot(pCur);
  if( rc ) return rc;
  assert( pCur->pPage );
  assert( pCur->pPage->isInit );
  if( pCur->isValid==0 ){
    *pRes = -1;
    assert( pCur->pPage->nCell==0 );
    return SQLITE_OK;
  }
   for(;;){
    int lwr, upr;
    Pgno chldPg;
    MemPage *pPage = pCur->pPage;
    int c = -1;  /* pRes return if table is empty must be -1 */
    lwr = 0;
    upr = pPage->nCell-1;
    if( !pPage->intKey && pKey==0 ){
      return SQLITE_CORRUPT;
    }
    pageIntegrity(pPage);
    while( lwr<=upr ){
      void *pCellKey;
      i64 nCellKey;
      pCur->idx = (lwr+upr)/2;
      pCur->info.nSize = 0;
      sqlite3BtreeKeySize(pCur, &nCellKey);
      if( pPage->intKey ){
        if( nCellKey<nKey ){
          c = -1;
        }else if( nCellKey>nKey ){
          c = +1;
        }else{
          c = 0;
        }
      }else{
        int available;
        pCellKey = (void *)fetchPayload(pCur, &available, 0);
        if( available>=nCellKey ){
          c = pCur->xCompare(pCur->pArg, nCellKey, pCellKey, nKey, pKey);
        }else{
          pCellKey = sqliteMallocRaw( nCellKey );
          if( pCellKey==0 ) return SQLITE_NOMEM;
          rc = sqlite3BtreeKey(pCur, 0, nCellKey, (void *)pCellKey);
          c = pCur->xCompare(pCur->pArg, nCellKey, pCellKey, nKey, pKey);
          sqliteFree(pCellKey);
          if( rc ) return rc;
        }
      }
      if( c==0 ){
        if( pPage->leafData && !pPage->leaf ){
          lwr = pCur->idx;
          upr = lwr - 1;
          break;
        }else{
          if( pRes ) *pRes = 0;
          return SQLITE_OK;
        }
      }
      if( c<0 ){
        lwr = pCur->idx+1;
      }else{
        upr = pCur->idx-1;
      }
    }
    assert( lwr==upr+1 );
    assert( pPage->isInit );
    if( pPage->leaf ){
      chldPg = 0;
    }else if( lwr>=pPage->nCell ){
      chldPg = get4byte(&pPage->aData[pPage->hdrOffset+8]);
    }else{
      chldPg = get4byte(findCell(pPage, lwr));
    }
    if( chldPg==0 ){
      assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell );
      if( pRes ) *pRes = c;
      return SQLITE_OK;
    }
    pCur->idx = lwr;
    pCur->info.nSize = 0;
    rc = moveToChild(pCur, chldPg);
    if( rc ){
      return rc;
    }
  }
  /* NOT REACHED */
}

/*
** Return TRUE if the cursor is not pointing at an entry of the table.
**
** TRUE will be returned after a call to sqlite3BtreeNext() moves
** past the last entry in the table or sqlite3BtreePrev() moves past
** the first entry.  TRUE is also returned if the table is empty.
*/
int sqlite3BtreeEof(BtCursor *pCur){
  return pCur->isValid==0;
}

/*
** Advance the cursor to the next entry in the database.  If
** successful then set *pRes=0.  If the cursor
** was already pointing to the last entry in the database before
** this routine was called, then set *pRes=1.
*/
int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
  int rc;
  MemPage *pPage = pCur->pPage;

  assert( pRes!=0 );
  if( pCur->isValid==0 ){
    *pRes = 1;
    return SQLITE_OK;
  }
  assert( pPage->isInit );
  assert( pCur->idx<pPage->nCell );

  pCur->idx++;
  pCur->info.nSize = 0;
  if( pCur->idx>=pPage->nCell ){
    if( !pPage->leaf ){
      rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
      if( rc ) return rc;
      rc = moveToLeftmost(pCur);
      *pRes = 0;
      return rc;
    }
    do{
      if( isRootPage(pPage) ){
        *pRes = 1;
        pCur->isValid = 0;
        return SQLITE_OK;
      }
      moveToParent(pCur);
      pPage = pCur->pPage;
    }while( pCur->idx>=pPage->nCell );
    *pRes = 0;
    if( pPage->leafData ){
      rc = sqlite3BtreeNext(pCur, pRes);
    }else{
      rc = SQLITE_OK;
    }
    return rc;
  }
  *pRes = 0;
  if( pPage->leaf ){
    return SQLITE_OK;
  }
  rc = moveToLeftmost(pCur);
  return rc;
}

/*
** Step the cursor to the back to the previous entry in the database.  If
** successful then set *pRes=0.  If the cursor
** was already pointing to the first entry in the database before
** this routine was called, then set *pRes=1.
*/
int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
  int rc;
  Pgno pgno;
  MemPage *pPage;
  if( pCur->isValid==0 ){
    *pRes = 1;
    return SQLITE_OK;
  }

  pPage = pCur->pPage;
  assert( pPage->isInit );
  assert( pCur->idx>=0 );
  if( !pPage->leaf ){
    pgno = get4byte( findCell(pPage, pCur->idx) );
    rc = moveToChild(pCur, pgno);
    if( rc ) return rc;
    rc = moveToRightmost(pCur);
  }else{
    while( pCur->idx==0 ){
      if( isRootPage(pPage) ){
        pCur->isValid = 0;
        *pRes = 1;
        return SQLITE_OK;
      }
      moveToParent(pCur);
      pPage = pCur->pPage;
    }
    pCur->idx--;
    pCur->info.nSize = 0;
    if( pPage->leafData && !pPage->leaf ){
      rc = sqlite3BtreePrevious(pCur, pRes);
    }else{
      rc = SQLITE_OK;
    }
  }
  *pRes = 0;
  return rc;
}

/*
** Allocate a new page from the database file.
**
** The new page is marked as dirty.  (In other words, sqlite3pager_write()
** has already been called on the new page.)  The new page has also
** been referenced and the calling routine is responsible for calling
** sqlite3pager_unref() on the new page when it is done.
**
** SQLITE_OK is returned on success.  Any other return value indicates
** an error.  *ppPage and *pPgno are undefined in the event of an error.
** Do not invoke sqlite3pager_unref() on *ppPage if an error is returned.
**
** If the "nearby" parameter is not 0, then a (feeble) effort is made to 
** locate a page close to the page number "nearby".  This can be used in an
** attempt to keep related pages close to each other in the database file,
** which in turn can make database access faster.
**
** If the "exact" parameter is not 0, and the page-number nearby exists 
** anywhere on the free-list, then it is guarenteed to be returned. This
** is only used by auto-vacuum databases when allocating a new table.
*/
static int allocatePage(
  Btree *pBt, 
  MemPage **ppPage, 
  Pgno *pPgno, 
  Pgno nearby,
  u8 exact
){
  MemPage *pPage1;
  int rc;
  int n;     /* Number of pages on the freelist */
  int k;     /* Number of leaves on the trunk of the freelist */

  pPage1 = pBt->pPage1;
  n = get4byte(&pPage1->aData[36]);
  if( n>0 ){
    /* There are pages on the freelist.  Reuse one of those pages. */
    MemPage *pTrunk = 0;
    Pgno iTrunk;
    MemPage *pPrevTrunk = 0;
    u8 searchList = 0; /* If the free-list must be searched for 'nearby' */
    
    /* If the 'exact' parameter was true and a query of the pointer-map
    ** shows that the page 'nearby' is somewhere on the free-list, then
    ** the entire-list will be searched for that page.
    */
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( exact ){
      u8 eType;
      assert( nearby>0 );
      assert( pBt->autoVacuum );
      rc = ptrmapGet(pBt, nearby, &eType, 0);
      if( rc ) return rc;
      if( eType==PTRMAP_FREEPAGE ){
        searchList = 1;
      }
      *pPgno = nearby;
    }
#endif

    /* Decrement the free-list count by 1. Set iTrunk to the index of the
    ** first free-list trunk page. iPrevTrunk is initially 1.
    */
    rc = sqlite3pager_write(pPage1->aData);
    if( rc ) return rc;
    put4byte(&pPage1->aData[36], n-1);

    /* The code within this loop is run only once if the 'searchList' variable
    ** is not true. Otherwise, it runs once for each trunk-page on the
    ** free-list until the page 'nearby' is located.
    */
    do {
      pPrevTrunk = pTrunk;
      if( pPrevTrunk ){
        iTrunk = get4byte(&pPrevTrunk->aData[0]);
      }else{
        iTrunk = get4byte(&pPage1->aData[32]);
      }
      rc = getPage(pBt, iTrunk, &pTrunk);
      if( rc ){
        releasePage(pPrevTrunk);
        return rc;
      }

      /* TODO: This should move to after the loop? */
      rc = sqlite3pager_write(pTrunk->aData);
      if( rc ){
        releasePage(pTrunk);
        releasePage(pPrevTrunk);
        return rc;
      }

      k = get4byte(&pTrunk->aData[4]);
      if( k==0 && !searchList ){
        /* The trunk has no leaves and the list is not being searched. 
        ** So extract the trunk page itself and use it as the newly 
        ** allocated page */
        assert( pPrevTrunk==0 );
        *pPgno = iTrunk;
        memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);
        *ppPage = pTrunk;
        pTrunk = 0;
        TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
      }else if( k>pBt->usableSize/4 - 8 ){
        /* Value of k is out of range.  Database corruption */
        return SQLITE_CORRUPT; /* bkpt-CORRUPT */
#ifndef SQLITE_OMIT_AUTOVACUUM
      }else if( searchList && nearby==iTrunk ){
        /* The list is being searched and this trunk page is the page
        ** to allocate, regardless of whether it has leaves.
        */
        assert( *pPgno==iTrunk );
        *ppPage = pTrunk;
        searchList = 0;
        if( k==0 ){
          if( !pPrevTrunk ){
            memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);
          }else{
            memcpy(&pPrevTrunk->aData[0], &pTrunk->aData[0], 4);
          }
        }else{
          /* The trunk page is required by the caller but it contains 
          ** pointers to free-list leaves. The first leaf becomes a trunk
          ** page in this case.
          */
          MemPage *pNewTrunk;
          Pgno iNewTrunk = get4byte(&pTrunk->aData[8]);
          rc = getPage(pBt, iNewTrunk, &pNewTrunk);
          if( rc!=SQLITE_OK ){
            releasePage(pTrunk);
            releasePage(pPrevTrunk);
            return rc;
          }
          rc = sqlite3pager_write(pNewTrunk->aData);
          if( rc!=SQLITE_OK ){
            releasePage(pNewTrunk);
            releasePage(pTrunk);
            releasePage(pPrevTrunk);
            return rc;
          }
          memcpy(&pNewTrunk->aData[0], &pTrunk->aData[0], 4);
          put4byte(&pNewTrunk->aData[4], k-1);
          memcpy(&pNewTrunk->aData[8], &pTrunk->aData[12], (k-1)*4);
          if( !pPrevTrunk ){
            put4byte(&pPage1->aData[32], iNewTrunk);
          }else{
            put4byte(&pPrevTrunk->aData[0], iNewTrunk);
          }
          releasePage(pNewTrunk);
        }
        pTrunk = 0;
        TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
#endif
      }else{
        /* Extract a leaf from the trunk */
        int closest;
        Pgno iPage;
        unsigned char *aData = pTrunk->aData;
        if( nearby>0 ){
          int i, dist;
          closest = 0;
          dist = get4byte(&aData[8]) - nearby;
          if( dist<0 ) dist = -dist;
          for(i=1; i<k; i++){
            int d2 = get4byte(&aData[8+i*4]) - nearby;
            if( d2<0 ) d2 = -d2;
            if( d2<dist ){
              closest = i;
              dist = d2;
            }
          }
        }else{
          closest = 0;
        }

        iPage = get4byte(&aData[8+closest*4]);
        if( !searchList || iPage==nearby ){
          *pPgno = iPage;
          if( *pPgno>sqlite3pager_pagecount(pBt->pPager) ){
            /* Free page off the end of the file */
            return SQLITE_CORRUPT; /* bkpt-CORRUPT */
          }
          TRACE(("ALLOCATE: %d was leaf %d of %d on trunk %d"
                 ": %d more free pages\n",
                 *pPgno, closest+1, k, pTrunk->pgno, n-1));
          if( closest<k-1 ){
            memcpy(&aData[8+closest*4], &aData[4+k*4], 4);
          }
          put4byte(&aData[4], k-1);
          rc = getPage(pBt, *pPgno, ppPage);
          if( rc==SQLITE_OK ){
            sqlite3pager_dont_rollback((*ppPage)->aData);
            rc = sqlite3pager_write((*ppPage)->aData);
            if( rc!=SQLITE_OK ){
              releasePage(*ppPage);
            }
          }
          searchList = 0;
        }
      }
      releasePage(pPrevTrunk);
    }while( searchList );
    releasePage(pTrunk);
  }else{
    /* There are no pages on the freelist, so create a new page at the
    ** end of the file */
    *pPgno = sqlite3pager_pagecount(pBt->pPager) + 1;

#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum && PTRMAP_ISPAGE(pBt->usableSize, *pPgno) ){
      /* If *pPgno refers to a pointer-map page, allocate two new pages
      ** at the end of the file instead of one. The first allocated page
      ** becomes a new pointer-map page, the second is used by the caller.
      */
      TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", *pPgno));
      assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
      (*pPgno)++;
    }
#endif

    assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
    rc = getPage(pBt, *pPgno, ppPage);
    if( rc ) return rc;
    rc = sqlite3pager_write((*ppPage)->aData);
    if( rc!=SQLITE_OK ){
      releasePage(*ppPage);
    }
    TRACE(("ALLOCATE: %d from end of file\n", *pPgno));
  }

  assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
  return rc;
}

/*
** Add a page of the database file to the freelist.
**
** sqlite3pager_unref() is NOT called for pPage.
*/
static int freePage(MemPage *pPage){
  Btree *pBt = pPage->pBt;
  MemPage *pPage1 = pBt->pPage1;
  int rc, n, k;

  /* Prepare the page for freeing */
  assert( pPage->pgno>1 );
  pPage->isInit = 0;
  releasePage(pPage->pParent);
  pPage->pParent = 0;

  /* Increment the free page count on pPage1 */
  rc = sqlite3pager_write(pPage1->aData);
  if( rc ) return rc;
  n = get4byte(&pPage1->aData[36]);
  put4byte(&pPage1->aData[36], n+1);

#ifndef SQLITE_OMIT_AUTOVACUUM
  /* If the database supports auto-vacuum, write an entry in the pointer-map
  ** to indicate that the page is free.
  */
  if( pBt->autoVacuum ){
    rc = ptrmapPut(pBt, pPage->pgno, PTRMAP_FREEPAGE, 0);
    if( rc ) return rc;
  }
#endif

  if( n==0 ){
    /* This is the first free page */
    rc = sqlite3pager_write(pPage->aData);
    if( rc ) return rc;
    memset(pPage->aData, 0, 8);
    put4byte(&pPage1->aData[32], pPage->pgno);
    TRACE(("FREE-PAGE: %d first\n", pPage->pgno));
  }else{
    /* Other free pages already exist.  Retrive the first trunk page
    ** of the freelist and find out how many leaves it has. */
    MemPage *pTrunk;
    rc = getPage(pBt, get4byte(&pPage1->aData[32]), &pTrunk);
    if( rc ) return rc;
    k = get4byte(&pTrunk->aData[4]);
    if( k>=pBt->usableSize/4 - 8 ){
      /* The trunk is full.  Turn the page being freed into a new
      ** trunk page with no leaves. */
      rc = sqlite3pager_write(pPage->aData);
      if( rc ) return rc;
      put4byte(pPage->aData, pTrunk->pgno);
      put4byte(&pPage->aData[4], 0);
      put4byte(&pPage1->aData[32], pPage->pgno);
      TRACE(("FREE-PAGE: %d new trunk page replacing %d\n",
              pPage->pgno, pTrunk->pgno));
    }else{
      /* Add the newly freed page as a leaf on the current trunk */
      rc = sqlite3pager_write(pTrunk->aData);
      if( rc ) return rc;
      put4byte(&pTrunk->aData[4], k+1);
      put4byte(&pTrunk->aData[8+k*4], pPage->pgno);
      sqlite3pager_dont_write(pBt->pPager, pPage->pgno);
      TRACE(("FREE-PAGE: %d leaf on trunk page %d\n",pPage->pgno,pTrunk->pgno));
    }
    releasePage(pTrunk);
  }
  return rc;
}

/*
** Free any overflow pages associated with the given Cell.
*/
static int clearCell(MemPage *pPage, unsigned char *pCell){
  Btree *pBt = pPage->pBt;
  CellInfo info;
  Pgno ovflPgno;
  int rc;

  parseCellPtr(pPage, pCell, &info);
  if( info.iOverflow==0 ){
    return SQLITE_OK;  /* No overflow pages. Return without doing anything */
  }
  ovflPgno = get4byte(&pCell[info.iOverflow]);
  while( ovflPgno!=0 ){
    MemPage *pOvfl;
    if( ovflPgno>sqlite3pager_pagecount(pBt->pPager) ){
      return SQLITE_CORRUPT;
    }
    rc = getPage(pBt, ovflPgno, &pOvfl);
    if( rc ) return rc;
    ovflPgno = get4byte(pOvfl->aData);
    rc = freePage(pOvfl);
    if( rc ) return rc;
    sqlite3pager_unref(pOvfl->aData);
  }
  return SQLITE_OK;
}

/*
** Create the byte sequence used to represent a cell on page pPage
** and write that byte sequence into pCell[].  Overflow pages are
** allocated and filled in as necessary.  The calling procedure
** is responsible for making sure sufficient space has been allocated
** for pCell[].
**
** Note that pCell does not necessary need to point to the pPage->aData
** area.  pCell might point to some temporary storage.  The cell will
** be constructed in this temporary area then copied into pPage->aData
** later.
*/
static int fillInCell(
  MemPage *pPage,                /* The page that contains the cell */
  unsigned char *pCell,          /* Complete text of the cell */
  const void *pKey, i64 nKey,    /* The key */
  const void *pData,int nData,   /* The data */
  int *pnSize                    /* Write cell size here */
){
  int nPayload;
  const u8 *pSrc;
  int nSrc, n, rc;
  int spaceLeft;
  MemPage *pOvfl = 0;
  MemPage *pToRelease = 0;
  unsigned char *pPrior;
  unsigned char *pPayload;
  Btree *pBt = pPage->pBt;
  Pgno pgnoOvfl = 0;
  int nHeader;
  CellInfo info;

  /* Fill in the header. */
  nHeader = 0;
  if( !pPage->leaf ){
    nHeader += 4;
  }
  if( pPage->hasData ){
    nHeader += putVarint(&pCell[nHeader], nData);
  }else{
    nData = 0;
  }
  nHeader += putVarint(&pCell[nHeader], *(u64*)&nKey);
  parseCellPtr(pPage, pCell, &info);
  assert( info.nHeader==nHeader );
  assert( info.nKey==nKey );
  assert( info.nData==nData );
  
  /* Fill in the payload */
  nPayload = nData;
  if( pPage->intKey ){
    pSrc = pData;
    nSrc = nData;
    nData = 0;
  }else{
    nPayload += nKey;
    pSrc = pKey;
    nSrc = nKey;
  }
  *pnSize = info.nSize;
  spaceLeft = info.nLocal;
  pPayload = &pCell[nHeader];
  pPrior = &pCell[info.iOverflow];

  while( nPayload>0 ){
    if( spaceLeft==0 ){
#ifndef SQLITE_OMIT_AUTOVACUUM
      Pgno pgnoPtrmap = pgnoOvfl; /* Overflow page pointer-map entry page */
#endif
      rc = allocatePage(pBt, &pOvfl, &pgnoOvfl, pgnoOvfl, 0);
#ifndef SQLITE_OMIT_AUTOVACUUM
      /* If the database supports auto-vacuum, and the second or subsequent
      ** overflow page is being allocated, add an entry to the pointer-map
      ** for that page now. The entry for the first overflow page will be
      ** added later, by the insertCell() routine.
      */
      if( pBt->autoVacuum && pgnoPtrmap!=0 && rc==SQLITE_OK ){
        rc = ptrmapPut(pBt, pgnoOvfl, PTRMAP_OVERFLOW2, pgnoPtrmap);
      }
#endif
      if( rc ){
        releasePage(pToRelease);
        /* clearCell(pPage, pCell); */
        return rc;
      }
      put4byte(pPrior, pgnoOvfl);
      releasePage(pToRelease);
      pToRelease = pOvfl;
      pPrior = pOvfl->aData;
      put4byte(pPrior, 0);
      pPayload = &pOvfl->aData[4];
      spaceLeft = pBt->usableSize - 4;
    }
    n = nPayload;
    if( n>spaceLeft ) n = spaceLeft;
    if( n>nSrc ) n = nSrc;
    memcpy(pPayload, pSrc, n);
    nPayload -= n;
    pPayload += n;
    pSrc += n;
    nSrc -= n;
    spaceLeft -= n;
    if( nSrc==0 ){
      nSrc = nData;
      pSrc = pData;
    }
  }
  releasePage(pToRelease);
  return SQLITE_OK;
}

/*
** Change the MemPage.pParent pointer on the page whose number is
** given in the second argument so that MemPage.pParent holds the
** pointer in the third argument.
*/
static int reparentPage(Btree *pBt, Pgno pgno, MemPage *pNewParent, int idx){
  MemPage *pThis;
  unsigned char *aData;

  if( pgno==0 ) return SQLITE_OK;
  assert( pBt->pPager!=0 );
  aData = sqlite3pager_lookup(pBt->pPager, pgno);
  if( aData ){
    pThis = (MemPage*)&aData[pBt->psAligned];
    assert( pThis->aData==aData );
    if( pThis->isInit ){
      if( pThis->pParent!=pNewParent ){
        if( pThis->pParent ) sqlite3pager_unref(pThis->pParent->aData);
        pThis->pParent = pNewParent;
        if( pNewParent ) sqlite3pager_ref(pNewParent->aData);
      }
      pThis->idxParent = idx;
    }
    sqlite3pager_unref(aData);
  }

#ifndef SQLITE_OMIT_AUTOVACUUM
  if( pBt->autoVacuum ){
    return ptrmapPut(pBt, pgno, PTRMAP_BTREE, pNewParent->pgno);
  }
#endif
  return SQLITE_OK;
}



/*
** Change the pParent pointer of all children of pPage to point back
** to pPage.
**
** In other words, for every child of pPage, invoke reparentPage()
** to make sure that each child knows that pPage is its parent.
**
** This routine gets called after you memcpy() one page into
** another.
*/
static int reparentChildPages(MemPage *pPage){
  int i;
  Btree *pBt = pPage->pBt;
  int rc = SQLITE_OK;

  if( pPage->leaf ) return SQLITE_OK;

  for(i=0; i<pPage->nCell; i++){
    u8 *pCell = findCell(pPage, i);
    if( !pPage->leaf ){
      rc = reparentPage(pBt, get4byte(pCell), pPage, i);
      if( rc!=SQLITE_OK ) return rc;
    }
  }
  if( !pPage->leaf ){
    rc = reparentPage(pBt, get4byte(&pPage->aData[pPage->hdrOffset+8]), 
       pPage, i);
    pPage->idxShift = 0;
  }
  return rc;
}

/*
** Remove the i-th cell from pPage.  This routine effects pPage only.
** The cell content is not freed or deallocated.  It is assumed that
** the cell content has been copied someplace else.  This routine just
** removes the reference to the cell from pPage.
**
** "sz" must be the number of bytes in the cell.
*/
static void dropCell(MemPage *pPage, int idx, int sz){
  int i;          /* Loop counter */
  int pc;         /* Offset to cell content of cell being deleted */
  u8 *data;       /* pPage->aData */
  u8 *ptr;        /* Used to move bytes around within data[] */

  assert( idx>=0 && idx<pPage->nCell );
  assert( sz==cellSize(pPage, idx) );
  assert( sqlite3pager_iswriteable(pPage->aData) );
  data = pPage->aData;
  ptr = &data[pPage->cellOffset + 2*idx];
  pc = get2byte(ptr);
  assert( pc>10 && pc+sz<=pPage->pBt->usableSize );
  freeSpace(pPage, pc, sz);
  for(i=idx+1; i<pPage->nCell; i++, ptr+=2){
    ptr[0] = ptr[2];
    ptr[1] = ptr[3];
  }
  pPage->nCell--;
  put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
  pPage->nFree += 2;
  pPage->idxShift = 1;
}

/*
** Insert a new cell on pPage at cell index "i".  pCell points to the
** content of the cell.
**
** If the cell content will fit on the page, then put it there.  If it
** will not fit, then make a copy of the cell content into pTemp if
** pTemp is not null.  Regardless of pTemp, allocate a new entry
** in pPage->aOvfl[] and make it point to the cell content (either
** in pTemp or the original pCell) and also record its index. 
** Allocating a new entry in pPage->aCell[] implies that 
** pPage->nOverflow is incremented.
**
** If nSkip is non-zero, then do not copy the first nSkip bytes of the
** cell. The caller will overwrite them after this function returns. If
** nSkip is non-zero, then pCell may not point to an invalid memory location 
** (but pCell+nSkip is always valid).
*/
static int insertCell(
  MemPage *pPage,   /* Page into which we are copying */
  int i,            /* New cell becomes the i-th cell of the page */
  u8 *pCell,        /* Content of the new cell */
  int sz,           /* Bytes of content in pCell */
  u8 *pTemp,        /* Temp storage space for pCell, if needed */
  u8 nSkip          /* Do not write the first nSkip bytes of the cell */
){
  int idx;          /* Where to write new cell content in data[] */
  int j;            /* Loop counter */
  int top;          /* First byte of content for any cell in data[] */
  int end;          /* First byte past the last cell pointer in data[] */
  int ins;          /* Index in data[] where new cell pointer is inserted */
  int hdr;          /* Offset into data[] of the page header */
  int cellOffset;   /* Address of first cell pointer in data[] */
  u8 *data;         /* The content of the whole page */
  u8 *ptr;          /* Used for moving information around in data[] */

  assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );
  assert( sz==cellSizePtr(pPage, pCell) );
  assert( sqlite3pager_iswriteable(pPage->aData) );
  if( pPage->nOverflow || sz+2>pPage->nFree ){
    if( pTemp ){
      memcpy(pTemp+nSkip, pCell+nSkip, sz-nSkip);
      pCell = pTemp;
    }
    j = pPage->nOverflow++;
    assert( j<sizeof(pPage->aOvfl)/sizeof(pPage->aOvfl[0]) );
    pPage->aOvfl[j].pCell = pCell;
    pPage->aOvfl[j].idx = i;
    pPage->nFree = 0;
  }else{
    data = pPage->aData;
    hdr = pPage->hdrOffset;
    top = get2byte(&data[hdr+5]);
    cellOffset = pPage->cellOffset;
    end = cellOffset + 2*pPage->nCell + 2;
    ins = cellOffset + 2*i;
    if( end > top - sz ){
      defragmentPage(pPage);
      top = get2byte(&data[hdr+5]);
      assert( end + sz <= top );
    }
    idx = allocateSpace(pPage, sz);
    assert( idx>0 );
    assert( end <= get2byte(&data[hdr+5]) );
    pPage->nCell++;
    pPage->nFree -= 2;
    memcpy(&data[idx+nSkip], pCell+nSkip, sz-nSkip);
    for(j=end-2, ptr=&data[j]; j>ins; j-=2, ptr-=2){
      ptr[0] = ptr[-2];
      ptr[1] = ptr[-1];
    }
    put2byte(&data[ins], idx);
    put2byte(&data[hdr+3], pPage->nCell);
    pPage->idxShift = 1;
    pageIntegrity(pPage);
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pPage->pBt->autoVacuum ){
      /* The cell may contain a pointer to an overflow page. If so, write
      ** the entry for the overflow page into the pointer map.
      */
      CellInfo info;
      parseCellPtr(pPage, pCell, &info);
      if( (info.nData+(pPage->intKey?0:info.nKey))>info.nLocal ){
        Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
        int rc = ptrmapPut(pPage->pBt, pgnoOvfl, PTRMAP_OVERFLOW1, pPage->pgno);
        if( rc!=SQLITE_OK ) return rc;
      }
    }
#endif
  }

  return SQLITE_OK;
}

/*
** Add a list of cells to a page.  The page should be initially empty.
** The cells are guaranteed to fit on the page.
*/
static void assemblePage(
  MemPage *pPage,   /* The page to be assemblied */
  int nCell,        /* The number of cells to add to this page */
  u8 **apCell,      /* Pointers to cell bodies */
  int *aSize        /* Sizes of the cells */
){
  int i;            /* Loop counter */
  int totalSize;    /* Total size of all cells */
  int hdr;          /* Index of page header */
  int cellptr;      /* Address of next cell pointer */
  int cellbody;     /* Address of next cell body */
  u8 *data;         /* Data for the page */

  assert( pPage->nOverflow==0 );
  totalSize = 0;
  for(i=0; i<nCell; i++){
    totalSize += aSize[i];
  }
  assert( totalSize+2*nCell<=pPage->nFree );
  assert( pPage->nCell==0 );
  cellptr = pPage->cellOffset;
  data = pPage->aData;
  hdr = pPage->hdrOffset;
  put2byte(&data[hdr+3], nCell);
  cellbody = allocateSpace(pPage, totalSize);
  assert( cellbody>0 );
  assert( pPage->nFree >= 2*nCell );
  pPage->nFree -= 2*nCell;
  for(i=0; i<nCell; i++){
    put2byte(&data[cellptr], cellbody);
    memcpy(&data[cellbody], apCell[i], aSize[i]);
    cellptr += 2;
    cellbody += aSize[i];
  }
  assert( cellbody==pPage->pBt->usableSize );
  pPage->nCell = nCell;
}

/*
** The following parameters determine how many adjacent pages get involved
** in a balancing operation.  NN is the number of neighbors on either side
** of the page that participate in the balancing operation.  NB is the
** total number of pages that participate, including the target page and
** NN neighbors on either side.
**
** The minimum value of NN is 1 (of course).  Increasing NN above 1
** (to 2 or 3) gives a modest improvement in SELECT and DELETE performance
** in exchange for a larger degradation in INSERT and UPDATE performance.
** The value of NN appears to give the best results overall.
*/
#define NN 1             /* Number of neighbors on either side of pPage */
#define NB (NN*2+1)      /* Total pages involved in the balance */

/* Forward reference */
static int balance(MemPage*, int);

#ifndef SQLITE_OMIT_QUICKBALANCE
/*
** This version of balance() handles the common special case where
** a new entry is being inserted on the extreme right-end of the
** tree, in other words, when the new entry will become the largest
** entry in the tree.
**
** Instead of trying balance the 3 right-most leaf pages, just add
** a new page to the right-hand side and put the one new entry in
** that page.  This leaves the right side of the tree somewhat
** unbalanced.  But odds are that we will be inserting new entries
** at the end soon afterwards so the nearly empty page will quickly
** fill up.  On average.
**
** pPage is the leaf page which is the right-most page in the tree.
** pParent is its parent.  pPage must have a single overflow entry
** which is also the right-most entry on the page.
*/
static int balance_quick(MemPage *pPage, MemPage *pParent){
  int rc;
  MemPage *pNew;
  Pgno pgnoNew;
  u8 *pCell;
  int szCell;
  CellInfo info;
  Btree *pBt = pPage->pBt;
  int parentIdx = pParent->nCell;   /* pParent new divider cell index */
  int parentSize;                   /* Size of new divider cell */
  u8 parentCell[64];                /* Space for the new divider cell */

  /* Allocate a new page. Insert the overflow cell from pPage
  ** into it. Then remove the overflow cell from pPage.
  */
  rc = allocatePage(pBt, &pNew, &pgnoNew, 0, 0);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  pCell = pPage->aOvfl[0].pCell;
  szCell = cellSizePtr(pPage, pCell);
  zeroPage(pNew, pPage->aData[0]);
  assemblePage(pNew, 1, &pCell, &szCell);
  pPage->nOverflow = 0;

  /* Set the parent of the newly allocated page to pParent. */
  pNew->pParent = pParent;
  sqlite3pager_ref(pParent->aData);

  /* pPage is currently the right-child of pParent. Change this
  ** so that the right-child is the new page allocated above and
  ** pPage is the next-to-right child. 
  */
  assert( pPage->nCell>0 );
  parseCellPtr(pPage, findCell(pPage, pPage->nCell-1), &info);
  rc = fillInCell(pParent, parentCell, 0, info.nKey, 0, 0, &parentSize);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  assert( parentSize<64 );
  rc = insertCell(pParent, parentIdx, parentCell, parentSize, 0, 4);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  put4byte(findOverflowCell(pParent,parentIdx), pPage->pgno);
  put4byte(&pParent->aData[pParent->hdrOffset+8], pgnoNew);

#ifndef SQLITE_OMIT_AUTOVACUUM
  /* If this is an auto-vacuum database, update the pointer map
  ** with entries for the new page, and any pointer from the 
  ** cell on the page to an overflow page.
  */
  if( pBt->autoVacuum ){
    rc = ptrmapPut(pBt, pgnoNew, PTRMAP_BTREE, pParent->pgno);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    rc = ptrmapPutOvfl(pNew, 0);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }
#endif

  /* Release the reference to the new page and balance the parent page,
  ** in case the divider cell inserted caused it to become overfull.
  */
  releasePage(pNew);
  return balance(pParent, 0);
}
#endif /* SQLITE_OMIT_QUICKBALANCE */

/*
** The ISAUTOVACUUM macro is used within balance_nonroot() to determine
** if the database supports auto-vacuum or not. Because it is used
** within an expression that is an argument to another macro 
** (sqliteMallocRaw), it is not possible to use conditional compilation.
** So, this macro is defined instead.
*/
#ifndef SQLITE_OMIT_AUTOVACUUM
#define ISAUTOVACUUM (pBt->autoVacuum)
#else
#define ISAUTOVACUUM 0
#endif

/*
** This routine redistributes Cells on pPage and up to NN*2 siblings
** of pPage so that all pages have about the same amount of free space.
** Usually NN siblings on either side of pPage is used in the balancing,
** though more siblings might come from one side if pPage is the first
** or last child of its parent.  If pPage has fewer than 2*NN siblings
** (something which can only happen if pPage is the root page or a 
** child of root) then all available siblings participate in the balancing.
**
** The number of siblings of pPage might be increased or decreased by one or
** two in an effort to keep pages nearly full but not over full. The root page
** is special and is allowed to be nearly empty. If pPage is 
** the root page, then the depth of the tree might be increased
** or decreased by one, as necessary, to keep the root page from being
** overfull or completely empty.
**
** Note that when this routine is called, some of the Cells on pPage
** might not actually be stored in pPage->aData[].  This can happen
** if the page is overfull.  Part of the job of this routine is to
** make sure all Cells for pPage once again fit in pPage->aData[].
**
** In the course of balancing the siblings of pPage, the parent of pPage
** might become overfull or underfull.  If that happens, then this routine
** is called recursively on the parent.
**
** If this routine fails for any reason, it might leave the database
** in a corrupted state.  So if this routine fails, the database should
** be rolled back.
*/
static int balance_nonroot(MemPage *pPage){
  MemPage *pParent;            /* The parent of pPage */
  Btree *pBt;                  /* The whole database */
  int nCell = 0;               /* Number of cells in aCell[] */
  int nOld;                    /* Number of pages in apOld[] */
  int nNew;                    /* Number of pages in apNew[] */
  int nDiv;                    /* Number of cells in apDiv[] */
  int i, j, k;                 /* Loop counters */
  int idx;                     /* Index of pPage in pParent->aCell[] */
  int nxDiv;                   /* Next divider slot in pParent->aCell[] */
  int rc;                      /* The return code */
  int leafCorrection;          /* 4 if pPage is a leaf.  0 if not */
  int leafData;                /* True if pPage is a leaf of a LEAFDATA tree */
  int usableSpace;             /* Bytes in pPage beyond the header */
  int pageFlags;               /* Value of pPage->aData[0] */
  int subtotal;                /* Subtotal of bytes in cells on one page */
  int iSpace = 0;              /* First unused byte of aSpace[] */
  int mxCellPerPage;           /* Maximum number of cells in one page */
  MemPage *apOld[NB];          /* pPage and up to two siblings */
  Pgno pgnoOld[NB];            /* Page numbers for each page in apOld[] */
  MemPage *apCopy[NB];         /* Private copies of apOld[] pages */
  MemPage *apNew[NB+2];        /* pPage and up to NB siblings after balancing */
  Pgno pgnoNew[NB+2];          /* Page numbers for each page in apNew[] */
  int idxDiv[NB];              /* Indices of divider cells in pParent */
  u8 *apDiv[NB];               /* Divider cells in pParent */
  int cntNew[NB+2];            /* Index in aCell[] of cell after i-th page */
  int szNew[NB+2];             /* Combined size of cells place on i-th page */
  u8 **apCell;                 /* All cells begin balanced */
  int *szCell;                 /* Local size of all cells in apCell[] */
  u8 *aCopy[NB];               /* Space for holding data of apCopy[] */
  u8 *aSpace;                  /* Space to hold copies of dividers cells */
#ifndef SQLITE_OMIT_AUTOVACUUM
  u8 *aFrom = 0;
#endif

  /* 
  ** Find the parent page.
  */
  assert( pPage->isInit );
  assert( sqlite3pager_iswriteable(pPage->aData) );
  pBt = pPage->pBt;
  pParent = pPage->pParent;
  sqlite3pager_write(pParent->aData);
  assert( pParent );
  TRACE(("BALANCE: begin page %d child of %d\n", pPage->pgno, pParent->pgno));

#ifndef SQLITE_OMIT_QUICKBALANCE
  /*
  ** A special case:  If a new entry has just been inserted into a
  ** table (that is, a btree with integer keys and all data at the leaves)
  ** an the new entry is the right-most entry in the tree (it has the
  ** largest key) then use the special balance_quick() routine for
  ** balancing.  balance_quick() is much faster and results in a tighter
  ** packing of data in the common case.
  */
  if( pPage->leaf &&
      pPage->intKey &&
      pPage->leafData &&
      pPage->nOverflow==1 &&
      pPage->aOvfl[0].idx==pPage->nCell &&
      pPage->pParent->pgno!=1 &&
      get4byte(&pParent->aData[pParent->hdrOffset+8])==pPage->pgno
  ){
    /*
    ** TODO: Check the siblings to the left of pPage. It may be that
    ** they are not full and no new page is required.
    */
    return balance_quick(pPage, pParent);
  }
#endif

  /*
  ** Allocate space for memory structures
  */
  mxCellPerPage = MX_CELL(pBt);
  apCell = sqliteMallocRaw( 
       (mxCellPerPage+2)*NB*(sizeof(u8*)+sizeof(int))
     + sizeof(MemPage)*NB
     + pBt->psAligned*(5+NB)
     + (ISAUTOVACUUM ? (mxCellPerPage+2)*NN*2 : 0)
  );
  if( apCell==0 ){
    return SQLITE_NOMEM;
  }
  szCell = (int*)&apCell[(mxCellPerPage+2)*NB];
  aCopy[0] = (u8*)&szCell[(mxCellPerPage+2)*NB];
  for(i=1; i<NB; i++){
    aCopy[i] = &aCopy[i-1][pBt->psAligned+sizeof(MemPage)];
  }
  aSpace = &aCopy[NB-1][pBt->psAligned+sizeof(MemPage)];
#ifndef SQLITE_OMIT_AUTOVACUUM
  if( pBt->autoVacuum ){
    aFrom = &aSpace[5*pBt->psAligned];
  }
#endif
  
  /*
  ** Find the cell in the parent page whose left child points back
  ** to pPage.  The "idx" variable is the index of that cell.  If pPage
  ** is the rightmost child of pParent then set idx to pParent->nCell 
  */
  if( pParent->idxShift ){
    Pgno pgno;
    pgno = pPage->pgno;
    assert( pgno==sqlite3pager_pagenumber(pPage->aData) );
    for(idx=0; idx<pParent->nCell; idx++){
      if( get4byte(findCell(pParent, idx))==pgno ){
        break;
      }
    }
    assert( idx<pParent->nCell
             || get4byte(&pParent->aData[pParent->hdrOffset+8])==pgno );
  }else{
    idx = pPage->idxParent;
  }

  /*
  ** Initialize variables so that it will be safe to jump
  ** directly to balance_cleanup at any moment.
  */
  nOld = nNew = 0;
  sqlite3pager_ref(pParent->aData);

  /*
  ** Find sibling pages to pPage and the cells in pParent that divide
  ** the siblings.  An attempt is made to find NN siblings on either
  ** side of pPage.  More siblings are taken from one side, however, if
  ** pPage there are fewer than NN siblings on the other side.  If pParent
  ** has NB or fewer children then all children of pParent are taken.
  */
  nxDiv = idx - NN;
  if( nxDiv + NB > pParent->nCell ){
    nxDiv = pParent->nCell - NB + 1;
  }
  if( nxDiv<0 ){
    nxDiv = 0;
  }
  nDiv = 0;
  for(i=0, k=nxDiv; i<NB; i++, k++){
    if( k<pParent->nCell ){
      idxDiv[i] = k;
      apDiv[i] = findCell(pParent, k);
      nDiv++;
      assert( !pParent->leaf );
      pgnoOld[i] = get4byte(apDiv[i]);
    }else if( k==pParent->nCell ){
      pgnoOld[i] = get4byte(&pParent->aData[pParent->hdrOffset+8]);
    }else{
      break;
    }
    rc = getAndInitPage(pBt, pgnoOld[i], &apOld[i], pParent);
    if( rc ) goto balance_cleanup;
    apOld[i]->idxParent = k;
    apCopy[i] = 0;
    assert( i==nOld );
    nOld++;
  }

  /*
  ** Make copies of the content of pPage and its siblings into aOld[].
  ** The rest of this function will use data from the copies rather
  ** that the original pages since the original pages will be in the
  ** process of being overwritten.
  */
  for(i=0; i<nOld; i++){
    MemPage *p = apCopy[i] = (MemPage*)&aCopy[i][pBt->psAligned];
    p->aData = &((u8*)p)[-pBt->psAligned];
    memcpy(p->aData, apOld[i]->aData, pBt->psAligned + sizeof(MemPage));
    p->aData = &((u8*)p)[-pBt->psAligned];
  }

  /*
  ** Load pointers to all cells on sibling pages and the divider cells
  ** into the local apCell[] array.  Make copies of the divider cells
  ** into space obtained form aSpace[] and remove the the divider Cells
  ** from pParent.
  **
  ** If the siblings are on leaf pages, then the child pointers of the
  ** divider cells are stripped from the cells before they are copied
  ** into aSpace[].  In this way, all cells in apCell[] are without
  ** child pointers.  If siblings are not leaves, then all cell in
  ** apCell[] include child pointers.  Either way, all cells in apCell[]
  ** are alike.
  **
  ** leafCorrection:  4 if pPage is a leaf.  0 if pPage is not a leaf.
  **       leafData:  1 if pPage holds key+data and pParent holds only keys.
  */
  nCell = 0;
  leafCorrection = pPage->leaf*4;
  leafData = pPage->leafData && pPage->leaf;
  for(i=0; i<nOld; i++){
    MemPage *pOld = apCopy[i];
    int limit = pOld->nCell+pOld->nOverflow;
    for(j=0; j<limit; j++){
      apCell[nCell] = findOverflowCell(pOld, j);
      szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pBt->autoVacuum ){
        int a;
        aFrom[nCell] = i;
        for(a=0; a<pOld->nOverflow; a++){
          if( pOld->aOvfl[a].pCell==apCell[nCell] ){
            aFrom[nCell] = 0xFF;
            break;
          }
        }
      }
#endif
      nCell++;
    }
    if( i<nOld-1 ){
      int sz = cellSizePtr(pParent, apDiv[i]);
      if( leafData ){
        /* With the LEAFDATA flag, pParent cells hold only INTKEYs that
        ** are duplicates of keys on the child pages.  We need to remove
        ** the divider cells from pParent, but the dividers cells are not
        ** added to apCell[] because they are duplicates of child cells.
        */
        dropCell(pParent, nxDiv, sz);
      }else{
        u8 *pTemp;
        szCell[nCell] = sz;
        pTemp = &aSpace[iSpace];
        iSpace += sz;
        assert( iSpace<=pBt->psAligned*5 );
        memcpy(pTemp, apDiv[i], sz);
        apCell[nCell] = pTemp+leafCorrection;
#ifndef SQLITE_OMIT_AUTOVACUUM
        if( pBt->autoVacuum ){
          aFrom[nCell] = 0xFF;
        }
#endif
        dropCell(pParent, nxDiv, sz);
        szCell[nCell] -= leafCorrection;
        assert( get4byte(pTemp)==pgnoOld[i] );
        if( !pOld->leaf ){
          assert( leafCorrection==0 );
          /* The right pointer of the child page pOld becomes the left
          ** pointer of the divider cell */
          memcpy(apCell[nCell], &pOld->aData[pOld->hdrOffset+8], 4);
        }else{
          assert( leafCorrection==4 );
        }
        nCell++;
      }
    }
  }

  /*
  ** Figure out the number of pages needed to hold all nCell cells.
  ** Store this number in "k".  Also compute szNew[] which is the total
  ** size of all cells on the i-th page and cntNew[] which is the index
  ** in apCell[] of the cell that divides page i from page i+1.  
  ** cntNew[k] should equal nCell.
  **
  ** Values computed by this block:
  **
  **           k: The total number of sibling pages
  **    szNew[i]: Spaced used on the i-th sibling page.
  **   cntNew[i]: Index in apCell[] and szCell[] for the first cell to
  **              the right of the i-th sibling page.
  ** usableSpace: Number of bytes of space available on each sibling.
  ** 
  */
  usableSpace = pBt->usableSize - 12 + leafCorrection;
  for(subtotal=k=i=0; i<nCell; i++){
    subtotal += szCell[i] + 2;
    if( subtotal > usableSpace ){
      szNew[k] = subtotal - szCell[i];
      cntNew[k] = i;
      if( leafData ){ i--; }
      subtotal = 0;
      k++;
    }
  }
  szNew[k] = subtotal;
  cntNew[k] = nCell;
  k++;

  /*
  ** The packing computed by the previous block is biased toward the siblings
  ** on the left side.  The left siblings are always nearly full, while the
  ** right-most sibling might be nearly empty.  This block of code attempts
  ** to adjust the packing of siblings to get a better balance.
  **
  ** This adjustment is more than an optimization.  The packing above might
  ** be so out of balance as to be illegal.  For example, the right-most
  ** sibling might be completely empty.  This adjustment is not optional.
  */
  for(i=k-1; i>0; i--){
    int szRight = szNew[i];  /* Size of sibling on the right */
    int szLeft = szNew[i-1]; /* Size of sibling on the left */
    int r;              /* Index of right-most cell in left sibling */
    int d;              /* Index of first cell to the left of right sibling */

    r = cntNew[i-1] - 1;
    d = r + 1 - leafData;
    while( szRight==0 || szRight+szCell[d]+2<=szLeft-(szCell[r]+2) ){
      szRight += szCell[d] + 2;
      szLeft -= szCell[r] + 2;
      cntNew[i-1]--;
      r = cntNew[i-1] - 1;
      d = r + 1 - leafData;
    }
    szNew[i] = szRight;
    szNew[i-1] = szLeft;
  }
  assert( cntNew[0]>0 );

  /*
  ** Allocate k new pages.  Reuse old pages where possible.
  */
  assert( pPage->pgno>1 );
  pageFlags = pPage->aData[0];
  for(i=0; i<k; i++){
    MemPage *pNew;
    if( i<nOld ){
      pNew = apNew[i] = apOld[i];
      pgnoNew[i] = pgnoOld[i];
      apOld[i] = 0;
      rc = sqlite3pager_write(pNew->aData);
      if( rc ) goto balance_cleanup;
    }else{
      rc = allocatePage(pBt, &pNew, &pgnoNew[i], pgnoNew[i-1], 0);
      if( rc ) goto balance_cleanup;
      apNew[i] = pNew;
    }
    nNew++;
    zeroPage(pNew, pageFlags);
  }

  /* Free any old pages that were not reused as new pages.
  */
  while( i<nOld ){
    rc = freePage(apOld[i]);
    if( rc ) goto balance_cleanup;
    releasePage(apOld[i]);
    apOld[i] = 0;
    i++;
  }

  /*
  ** Put the new pages in accending order.  This helps to
  ** keep entries in the disk file in order so that a scan
  ** of the table is a linear scan through the file.  That
  ** in turn helps the operating system to deliver pages
  ** from the disk more rapidly.
  **
  ** An O(n^2) insertion sort algorithm is used, but since
  ** n is never more than NB (a small constant), that should
  ** not be a problem.
  **
  ** When NB==3, this one optimization makes the database
  ** about 25% faster for large insertions and deletions.
  */
  for(i=0; i<k-1; i++){
    int minV = pgnoNew[i];
    int minI = i;
    for(j=i+1; j<k; j++){
      if( pgnoNew[j]<(unsigned)minV ){
        minI = j;
        minV = pgnoNew[j];
      }
    }
    if( minI>i ){
      int t;
      MemPage *pT;
      t = pgnoNew[i];
      pT = apNew[i];
      pgnoNew[i] = pgnoNew[minI];
      apNew[i] = apNew[minI];
      pgnoNew[minI] = t;
      apNew[minI] = pT;
    }
  }
  TRACE(("BALANCE: old: %d %d %d  new: %d(%d) %d(%d) %d(%d) %d(%d) %d(%d)\n",
    pgnoOld[0], 
    nOld>=2 ? pgnoOld[1] : 0,
    nOld>=3 ? pgnoOld[2] : 0,
    pgnoNew[0], szNew[0],
    nNew>=2 ? pgnoNew[1] : 0, nNew>=2 ? szNew[1] : 0,
    nNew>=3 ? pgnoNew[2] : 0, nNew>=3 ? szNew[2] : 0,
    nNew>=4 ? pgnoNew[3] : 0, nNew>=4 ? szNew[3] : 0,
    nNew>=5 ? pgnoNew[4] : 0, nNew>=5 ? szNew[4] : 0));

  /*
  ** Evenly distribute the data in apCell[] across the new pages.
  ** Insert divider cells into pParent as necessary.
  */
  j = 0;
  for(i=0; i<nNew; i++){
    /* Assemble the new sibling page. */
    MemPage *pNew = apNew[i];
    assert( pNew->pgno==pgnoNew[i] );
    assemblePage(pNew, cntNew[i]-j, &apCell[j], &szCell[j]);
    assert( pNew->nCell>0 );
    assert( pNew->nOverflow==0 );

#ifndef SQLITE_OMIT_AUTOVACUUM
    /* If this is an auto-vacuum database, update the pointer map entries
    ** that point to the siblings that were rearranged. These can be: left
    ** children of cells, the right-child of the page, or overflow pages
    ** pointed to by cells.
    */
    if( pBt->autoVacuum ){
      for(k=j; k<cntNew[i]; k++){
        if( aFrom[k]==0xFF || apCopy[aFrom[k]]->pgno!=pNew->pgno ){
          rc = ptrmapPutOvfl(pNew, k-j);
          if( rc!=SQLITE_OK ){
            goto balance_cleanup;
          }
        }
      }
    }
#endif

    j = cntNew[i];

    /* If the sibling page assembled above was not the right-most sibling,
    ** insert a divider cell into the parent page.
    */
    if( i<nNew-1 && j<nCell ){
      u8 *pCell;
      u8 *pTemp;
      int sz;
      pCell = apCell[j];
      sz = szCell[j] + leafCorrection;
      if( !pNew->leaf ){
        memcpy(&pNew->aData[8], pCell, 4);
        pTemp = 0;
      }else if( leafData ){
	/* If the tree is a leaf-data tree, and the siblings are leaves, 
        ** then there is no divider cell in apCell[]. Instead, the divider 
        ** cell consists of the integer key for the right-most cell of 
        ** the sibling-page assembled above only.
        */
        CellInfo info;
        j--;
        parseCellPtr(pNew, apCell[j], &info);
        pCell = &aSpace[iSpace];
        fillInCell(pParent, pCell, 0, info.nKey, 0, 0, &sz);
        iSpace += sz;
        assert( iSpace<=pBt->psAligned*5 );
        pTemp = 0;
      }else{
        pCell -= 4;
        pTemp = &aSpace[iSpace];
        iSpace += sz;
        assert( iSpace<=pBt->psAligned*5 );
      }
      rc = insertCell(pParent, nxDiv, pCell, sz, pTemp, 4);
      if( rc!=SQLITE_OK ) goto balance_cleanup;
      put4byte(findOverflowCell(pParent,nxDiv), pNew->pgno);
#ifndef SQLITE_OMIT_AUTOVACUUM
      /* If this is an auto-vacuum database, and not a leaf-data tree,
      ** then update the pointer map with an entry for the overflow page
      ** that the cell just inserted points to (if any).
      */
      if( pBt->autoVacuum && !leafData ){
        rc = ptrmapPutOvfl(pParent, nxDiv);
        if( rc!=SQLITE_OK ){
          goto balance_cleanup;
        }
      }
#endif
      j++;
      nxDiv++;
    }
  }
  assert( j==nCell );
  if( (pageFlags & PTF_LEAF)==0 ){
    memcpy(&apNew[nNew-1]->aData[8], &apCopy[nOld-1]->aData[8], 4);
  }
  if( nxDiv==pParent->nCell+pParent->nOverflow ){
    /* Right-most sibling is the right-most child of pParent */
    put4byte(&pParent->aData[pParent->hdrOffset+8], pgnoNew[nNew-1]);
  }else{
    /* Right-most sibling is the left child of the first entry in pParent
    ** past the right-most divider entry */
    put4byte(findOverflowCell(pParent, nxDiv), pgnoNew[nNew-1]);
  }

  /*
  ** Reparent children of all cells.
  */
  for(i=0; i<nNew; i++){
    rc = reparentChildPages(apNew[i]);
    if( rc!=SQLITE_OK ) goto balance_cleanup;
  }
  rc = reparentChildPages(pParent);
  if( rc!=SQLITE_OK ) goto balance_cleanup;

  /*
  ** Balance the parent page.  Note that the current page (pPage) might
  ** have been added to the freelist so it might no longer be initialized.
  ** But the parent page will always be initialized.
  */
  assert( pParent->isInit );
  /* assert( pPage->isInit ); // No! pPage might have been added to freelist */
  /* pageIntegrity(pPage);    // No! pPage might have been added to freelist */ 
  rc = balance(pParent, 0);
  
  /*
  ** Cleanup before returning.
  */
balance_cleanup:
  sqliteFree(apCell);
  for(i=0; i<nOld; i++){
    releasePage(apOld[i]);
  }
  for(i=0; i<nNew; i++){
    releasePage(apNew[i]);
  }
  releasePage(pParent);
  TRACE(("BALANCE: finished with %d: old=%d new=%d cells=%d\n",
          pPage->pgno, nOld, nNew, nCell));
  return rc;
}

/*
** This routine is called for the root page of a btree when the root
** page contains no cells.  This is an opportunity to make the tree
** shallower by one level.
*/
static int balance_shallower(MemPage *pPage){
  MemPage *pChild;             /* The only child page of pPage */
  Pgno pgnoChild;              /* Page number for pChild */
  int rc = SQLITE_OK;          /* Return code from subprocedures */
  Btree *pBt;                  /* The main BTree structure */
  int mxCellPerPage;           /* Maximum number of cells per page */
  u8 **apCell;                 /* All cells from pages being balanced */
  int *szCell;                 /* Local size of all cells */

  assert( pPage->pParent==0 );
  assert( pPage->nCell==0 );
  pBt = pPage->pBt;
  mxCellPerPage = MX_CELL(pBt);
  apCell = sqliteMallocRaw( mxCellPerPage*(sizeof(u8*)+sizeof(int)) );
  if( apCell==0 ) return SQLITE_NOMEM;
  szCell = (int*)&apCell[mxCellPerPage];
  if( pPage->leaf ){
    /* The table is completely empty */
    TRACE(("BALANCE: empty table %d\n", pPage->pgno));
  }else{
    /* The root page is empty but has one child.  Transfer the
    ** information from that one child into the root page if it 
    ** will fit.  This reduces the depth of the tree by one.
    **
    ** If the root page is page 1, it has less space available than
    ** its child (due to the 100 byte header that occurs at the beginning
    ** of the database fle), so it might not be able to hold all of the 
    ** information currently contained in the child.  If this is the 
    ** case, then do not do the transfer.  Leave page 1 empty except
    ** for the right-pointer to the child page.  The child page becomes
    ** the virtual root of the tree.
    */
    pgnoChild = get4byte(&pPage->aData[pPage->hdrOffset+8]);
    assert( pgnoChild>0 );
    assert( pgnoChild<=sqlite3pager_pagecount(pPage->pBt->pPager) );
    rc = getPage(pPage->pBt, pgnoChild, &pChild);
    if( rc ) goto end_shallow_balance;
    if( pPage->pgno==1 ){
      rc = initPage(pChild, pPage);
      if( rc ) goto end_shallow_balance;
      assert( pChild->nOverflow==0 );
      if( pChild->nFree>=100 ){
        /* The child information will fit on the root page, so do the
        ** copy */
        int i;
        zeroPage(pPage, pChild->aData[0]);
        for(i=0; i<pChild->nCell; i++){
          apCell[i] = findCell(pChild,i);
          szCell[i] = cellSizePtr(pChild, apCell[i]);
        }
        assemblePage(pPage, pChild->nCell, apCell, szCell);
        /* Copy the right-pointer of the child to the parent. */
        put4byte(&pPage->aData[pPage->hdrOffset+8], 
            get4byte(&pChild->aData[pChild->hdrOffset+8]));
        freePage(pChild);
        TRACE(("BALANCE: child %d transfer to page 1\n", pChild->pgno));
      }else{
        /* The child has more information that will fit on the root.
        ** The tree is already balanced.  Do nothing. */
        TRACE(("BALANCE: child %d will not fit on page 1\n", pChild->pgno));
      }
    }else{
      memcpy(pPage->aData, pChild->aData, pPage->pBt->usableSize);
      pPage->isInit = 0;
      pPage->pParent = 0;
      rc = initPage(pPage, 0);
      assert( rc==SQLITE_OK );
      freePage(pChild);
      TRACE(("BALANCE: transfer child %d into root %d\n",
              pChild->pgno, pPage->pgno));
    }
    rc = reparentChildPages(pPage);
    assert( pPage->nOverflow==0 );
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum ){
      int i;
      for(i=0; i<pPage->nCell; i++){ 
        rc = ptrmapPutOvfl(pPage, i);
        if( rc!=SQLITE_OK ){
          goto end_shallow_balance;
        }
      }
    }
#endif
    if( rc!=SQLITE_OK ) goto end_shallow_balance;
    releasePage(pChild);
  }
end_shallow_balance:
  sqliteFree(apCell);
  return rc;
}


/*
** The root page is overfull
**
** When this happens, Create a new child page and copy the
** contents of the root into the child.  Then make the root
** page an empty page with rightChild pointing to the new
** child.   Finally, call balance_internal() on the new child
** to cause it to split.
*/
static int balance_deeper(MemPage *pPage){
  int rc;             /* Return value from subprocedures */
  MemPage *pChild;    /* Pointer to a new child page */
  Pgno pgnoChild;     /* Page number of the new child page */
  Btree *pBt;         /* The BTree */
  int usableSize;     /* Total usable size of a page */
  u8 *data;           /* Content of the parent page */
  u8 *cdata;          /* Content of the child page */
  int hdr;            /* Offset to page header in parent */
  int brk;            /* Offset to content of first cell in parent */

  assert( pPage->pParent==0 );
  assert( pPage->nOverflow>0 );
  pBt = pPage->pBt;
  rc = allocatePage(pBt, &pChild, &pgnoChild, pPage->pgno, 0);
  if( rc ) return rc;
  assert( sqlite3pager_iswriteable(pChild->aData) );
  usableSize = pBt->usableSize;
  data = pPage->aData;
  hdr = pPage->hdrOffset;
  brk = get2byte(&data[hdr+5]);
  cdata = pChild->aData;
  memcpy(cdata, &data[hdr], pPage->cellOffset+2*pPage->nCell-hdr);
  memcpy(&cdata[brk], &data[brk], usableSize-brk);
  assert( pChild->isInit==0 );
  rc = initPage(pChild, pPage);
  if( rc ) return rc;
  memcpy(pChild->aOvfl, pPage->aOvfl, pPage->nOverflow*sizeof(pPage->aOvfl[0]));
  pChild->nOverflow = pPage->nOverflow;
  if( pChild->nOverflow ){
    pChild->nFree = 0;
  }
  assert( pChild->nCell==pPage->nCell );
  zeroPage(pPage, pChild->aData[0] & ~PTF_LEAF);
  put4byte(&pPage->aData[pPage->hdrOffset+8], pgnoChild);
  TRACE(("BALANCE: copy root %d into %d\n", pPage->pgno, pChild->pgno));
#ifndef SQLITE_OMIT_AUTOVACUUM
  if( pBt->autoVacuum ){
    int i;
    rc = ptrmapPut(pBt, pChild->pgno, PTRMAP_BTREE, pPage->pgno);
    if( rc ) return rc;
    for(i=0; i<pChild->nCell; i++){
      rc = ptrmapPutOvfl(pChild, i);
      if( rc!=SQLITE_OK ){
        return rc;
      }
    }
  }
#endif
  rc = balance_nonroot(pChild);
  releasePage(pChild);
  return rc;
}

/*
** Decide if the page pPage needs to be balanced.  If balancing is
** required, call the appropriate balancing routine.
*/
static int balance(MemPage *pPage, int insert){
  int rc = SQLITE_OK;
  if( pPage->pParent==0 ){
    if( pPage->nOverflow>0 ){
      rc = balance_deeper(pPage);
    }
    if( rc==SQLITE_OK && pPage->nCell==0 ){
      rc = balance_shallower(pPage);
    }
  }else{
    if( pPage->nOverflow>0 || 
        (!insert && pPage->nFree>pPage->pBt->usableSize*2/3) ){
      rc = balance_nonroot(pPage);
    }
  }
  return rc;
}

/*
** This routine checks all cursors that point to table pgnoRoot.
** If any of those cursors other than pExclude were opened with 
** wrFlag==0 then this routine returns SQLITE_LOCKED.  If all
** cursors that point to pgnoRoot were opened with wrFlag==1
** then this routine returns SQLITE_OK.
**
** In addition to checking for read-locks (where a read-lock 
** means a cursor opened with wrFlag==0) this routine also moves
** all cursors other than pExclude so that they are pointing to the 
** first Cell on root page.  This is necessary because an insert 
** or delete might change the number of cells on a page or delete
** a page entirely and we do not want to leave any cursors 
** pointing to non-existant pages or cells.
*/
static int checkReadLocks(Btree *pBt, Pgno pgnoRoot, BtCursor *pExclude){
  BtCursor *p;
  for(p=pBt->pCursor; p; p=p->pNext){
    if( p->pgnoRoot!=pgnoRoot || p==pExclude ) continue;
    if( p->wrFlag==0 ) return SQLITE_LOCKED;
    if( p->pPage->pgno!=p->pgnoRoot ){
      moveToRoot(p);
    }
  }
  return SQLITE_OK;
}

/*
** Insert a new record into the BTree.  The key is given by (pKey,nKey)
** and the data is given by (pData,nData).  The cursor is used only to
** define what table the record should be inserted into.  The cursor
** is left pointing at a random location.
**
** For an INTKEY table, only the nKey value of the key is used.  pKey is
** ignored.  For a ZERODATA table, the pData and nData are both ignored.
*/
int sqlite3BtreeInsert(
  BtCursor *pCur,                /* Insert data into the table of this cursor */
  const void *pKey, i64 nKey,    /* The key of the new record */
  const void *pData, int nData   /* The data of the new record */
){
  int rc;
  int loc;
  int szNew;
  MemPage *pPage;
  Btree *pBt = pCur->pBt;
  unsigned char *oldCell;
  unsigned char *newCell = 0;

  if( pBt->inTrans!=TRANS_WRITE ){
    /* Must start a transaction before doing an insert */
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }
  assert( !pBt->readOnly );
  if( !pCur->wrFlag ){
    return SQLITE_PERM;   /* Cursor not open for writing */
  }
  if( checkReadLocks(pBt, pCur->pgnoRoot, pCur) ){
    return SQLITE_LOCKED; /* The table pCur points to has a read lock */
  }
  rc = sqlite3BtreeMoveto(pCur, pKey, nKey, &loc);
  if( rc ) return rc;
  pPage = pCur->pPage;
  assert( pPage->intKey || nKey>=0 );
  assert( pPage->leaf || !pPage->leafData );
  TRACE(("INSERT: table=%d nkey=%lld ndata=%d page=%d %s\n",
          pCur->pgnoRoot, nKey, nData, pPage->pgno,
          loc==0 ? "overwrite" : "new entry"));
  assert( pPage->isInit );
  rc = sqlite3pager_write(pPage->aData);
  if( rc ) return rc;
  newCell = sqliteMallocRaw( MX_CELL_SIZE(pBt) );
  if( newCell==0 ) return SQLITE_NOMEM;
  rc = fillInCell(pPage, newCell, pKey, nKey, pData, nData, &szNew);
  if( rc ) goto end_insert;
  assert( szNew==cellSizePtr(pPage, newCell) );
  assert( szNew<=MX_CELL_SIZE(pBt) );
  if( loc==0 && pCur->isValid ){
    int szOld;
    assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
    oldCell = findCell(pPage, pCur->idx);
    if( !pPage->leaf ){
      memcpy(newCell, oldCell, 4);
    }
    szOld = cellSizePtr(pPage, oldCell);
    rc = clearCell(pPage, oldCell);
    if( rc ) goto end_insert;
    dropCell(pPage, pCur->idx, szOld);
  }else if( loc<0 && pPage->nCell>0 ){
    assert( pPage->leaf );
    pCur->idx++;
    pCur->info.nSize = 0;
  }else{
    assert( pPage->leaf );
  }
  rc = insertCell(pPage, pCur->idx, newCell, szNew, 0, 0);
  if( rc!=SQLITE_OK ) goto end_insert;
  rc = balance(pPage, 1);
  /* sqlite3BtreePageDump(pCur->pBt, pCur->pgnoRoot, 1); */
  /* fflush(stdout); */
  if( rc==SQLITE_OK ){
    moveToRoot(pCur);
  }
end_insert:
  sqliteFree(newCell);
  return rc;
}

/*
** Delete the entry that the cursor is pointing to.  The cursor
** is left pointing at a random location.
*/
int sqlite3BtreeDelete(BtCursor *pCur){
  MemPage *pPage = pCur->pPage;
  unsigned char *pCell;
  int rc;
  Pgno pgnoChild = 0;
  Btree *pBt = pCur->pBt;

  assert( pPage->isInit );
  if( pBt->inTrans!=TRANS_WRITE ){
    /* Must start a transaction before doing a delete */
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }
  assert( !pBt->readOnly );
  if( pCur->idx >= pPage->nCell ){
    return SQLITE_ERROR;  /* The cursor is not pointing to anything */
  }
  if( !pCur->wrFlag ){
    return SQLITE_PERM;   /* Did not open this cursor for writing */
  }
  if( checkReadLocks(pBt, pCur->pgnoRoot, pCur) ){
    return SQLITE_LOCKED; /* The table pCur points to has a read lock */
  }
  rc = sqlite3pager_write(pPage->aData);
  if( rc ) return rc;

  /* Locate the cell within it's page and leave pCell pointing to the
  ** data. The clearCell() call frees any overflow pages associated with the
  ** cell. The cell itself is still intact.
  */
  pCell = findCell(pPage, pCur->idx);
  if( !pPage->leaf ){
    pgnoChild = get4byte(pCell);
  }
  rc = clearCell(pPage, pCell);
  if( rc ) return rc;

  if( !pPage->leaf ){
    /*
    ** The entry we are about to delete is not a leaf so if we do not
    ** do something we will leave a hole on an internal page.
    ** We have to fill the hole by moving in a cell from a leaf.  The
    ** next Cell after the one to be deleted is guaranteed to exist and
    ** to be a leaf so we can use it.
    */
    BtCursor leafCur;
    unsigned char *pNext;
    int szNext;
    int notUsed;
    unsigned char *tempCell;
    assert( !pPage->leafData );
    getTempCursor(pCur, &leafCur);
    rc = sqlite3BtreeNext(&leafCur, &notUsed);
    if( rc!=SQLITE_OK ){
      if( rc!=SQLITE_NOMEM ){
        rc = SQLITE_CORRUPT;  /* bkpt-CORRUPT */
      }
      return rc;
    }
    rc = sqlite3pager_write(leafCur.pPage->aData);
    if( rc ) return rc;
    TRACE(("DELETE: table=%d delete internal from %d replace from leaf %d\n",
       pCur->pgnoRoot, pPage->pgno, leafCur.pPage->pgno));
    dropCell(pPage, pCur->idx, cellSizePtr(pPage, pCell));
    pNext = findCell(leafCur.pPage, leafCur.idx);
    szNext = cellSizePtr(leafCur.pPage, pNext);
    assert( MX_CELL_SIZE(pBt)>=szNext+4 );
    tempCell = sqliteMallocRaw( MX_CELL_SIZE(pBt) );
    if( tempCell==0 ) return SQLITE_NOMEM;
    rc = insertCell(pPage, pCur->idx, pNext-4, szNext+4, tempCell, 0);
    if( rc!=SQLITE_OK ) return rc;
    put4byte(findOverflowCell(pPage, pCur->idx), pgnoChild);
    rc = balance(pPage, 0);
    sqliteFree(tempCell);
    if( rc ) return rc;
    dropCell(leafCur.pPage, leafCur.idx, szNext);
    rc = balance(leafCur.pPage, 0);
    releaseTempCursor(&leafCur);
  }else{
    TRACE(("DELETE: table=%d delete from leaf %d\n",
       pCur->pgnoRoot, pPage->pgno));
    dropCell(pPage, pCur->idx, cellSizePtr(pPage, pCell));
    rc = balance(pPage, 0);
  }
  moveToRoot(pCur);
  return rc;
}

/*
** Create a new BTree table.  Write into *piTable the page
** number for the root page of the new table.
**
** The type of type is determined by the flags parameter.  Only the
** following values of flags are currently in use.  Other values for
** flags might not work:
**
**     BTREE_INTKEY|BTREE_LEAFDATA     Used for SQL tables with rowid keys
**     BTREE_ZERODATA                  Used for SQL indices
*/
int sqlite3BtreeCreateTable(Btree *pBt, int *piTable, int flags){
  MemPage *pRoot;
  Pgno pgnoRoot;
  int rc;
  if( pBt->inTrans!=TRANS_WRITE ){
    /* Must start a transaction first */
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }
  assert( !pBt->readOnly );

  /* It is illegal to create a table if any cursors are open on the
  ** database. This is because in auto-vacuum mode the backend may
  ** need to move a database page to make room for the new root-page.
  ** If an open cursor was using the page a problem would occur.
  */
  if( pBt->pCursor ){
    return SQLITE_LOCKED;
  }

#ifdef SQLITE_OMIT_AUTOVACUUM
  rc = allocatePage(pBt, &pRoot, &pgnoRoot, 1, 0);
  if( rc ) return rc;
#else
  if( pBt->autoVacuum ){
    Pgno pgnoMove;      /* Move a page here to make room for the root-page */
    MemPage *pPageMove; /* The page to move to. */

    /* Read the value of meta[3] from the database to determine where the
    ** root page of the new table should go. meta[3] is the largest root-page
    ** created so far, so the new root-page is (meta[3]+1).
    */
    rc = sqlite3BtreeGetMeta(pBt, 4, &pgnoRoot);
    if( rc!=SQLITE_OK ) return rc;
    pgnoRoot++;

    /* The new root-page may not be allocated on a pointer-map page, or the
    ** PENDING_BYTE page.
    */
    if( pgnoRoot==PTRMAP_PAGENO(pBt->usableSize, pgnoRoot) ||
        pgnoRoot==PENDING_BYTE_PAGE(pBt) ){
      pgnoRoot++;
    }
    assert( pgnoRoot>=3 );

    /* Allocate a page. The page that currently resides at pgnoRoot will
    ** be moved to the allocated page (unless the allocated page happens
    ** to reside at pgnoRoot).
    */
    rc = allocatePage(pBt, &pPageMove, &pgnoMove, pgnoRoot, 1);
    if( rc!=SQLITE_OK ){
      return rc;
    }

    if( pgnoMove!=pgnoRoot ){
      u8 eType;
      Pgno iPtrPage;

      releasePage(pPageMove);
      rc = getPage(pBt, pgnoRoot, &pRoot);
      if( rc!=SQLITE_OK ){
        return rc;
      }
      rc = ptrmapGet(pBt, pgnoRoot, &eType, &iPtrPage);
      assert( eType!=PTRMAP_ROOTPAGE );
      assert( eType!=PTRMAP_FREEPAGE );
      if( rc!=SQLITE_OK ){
        releasePage(pRoot);
        return rc;
      }
      rc = relocatePage(pBt, pRoot, eType, iPtrPage, pgnoMove);
      releasePage(pRoot);
      if( rc!=SQLITE_OK ){
        return rc;
      }
      rc = getPage(pBt, pgnoRoot, &pRoot);
      if( rc!=SQLITE_OK ){
        return rc;
      }
      rc = sqlite3pager_write(pRoot->aData);
      if( rc!=SQLITE_OK ){
        releasePage(pRoot);
        return rc;
      }
    }else{
      pRoot = pPageMove;
    } 

    /* Update the pointer-map and meta-data with the new root-page number. */
    rc = ptrmapPut(pBt, pgnoRoot, PTRMAP_ROOTPAGE, 0);
    if( rc ){
      releasePage(pRoot);
      return rc;
    }
    rc = sqlite3BtreeUpdateMeta(pBt, 4, pgnoRoot);
    if( rc ){
      releasePage(pRoot);
      return rc;
    }

  }else{
    rc = allocatePage(pBt, &pRoot, &pgnoRoot, 1, 0);
    if( rc ) return rc;
  }
#endif
  assert( sqlite3pager_iswriteable(pRoot->aData) );
  zeroPage(pRoot, flags | PTF_LEAF);
  sqlite3pager_unref(pRoot->aData);
  *piTable = (int)pgnoRoot;
  return SQLITE_OK;
}

/*
** Erase the given database page and all its children.  Return
** the page to the freelist.
*/
static int clearDatabasePage(
  Btree *pBt,           /* The BTree that contains the table */
  Pgno pgno,            /* Page number to clear */
  MemPage *pParent,     /* Parent page.  NULL for the root */
  int freePageFlag      /* Deallocate page if true */
){
  MemPage *pPage;
  int rc;
  unsigned char *pCell;
  int i;

  if( pgno>sqlite3pager_pagecount(pBt->pPager) ){
    return SQLITE_CORRUPT;
  }

  rc = getAndInitPage(pBt, pgno, &pPage, pParent);
  if( rc ) return rc;
  rc = sqlite3pager_write(pPage->aData);
  if( rc ) return rc;
  for(i=0; i<pPage->nCell; i++){
    pCell = findCell(pPage, i);
    if( !pPage->leaf ){
      rc = clearDatabasePage(pBt, get4byte(pCell), pPage->pParent, 1);
      if( rc ) return rc;
    }
    rc = clearCell(pPage, pCell);
    if( rc ) return rc;
  }
  if( !pPage->leaf ){
    rc = clearDatabasePage(pBt, get4byte(&pPage->aData[8]), pPage->pParent, 1);
    if( rc ) return rc;
  }
  if( freePageFlag ){
    rc = freePage(pPage);
  }else{
    zeroPage(pPage, pPage->aData[0] | PTF_LEAF);
  }
  releasePage(pPage);
  return rc;
}

/*
** Delete all information from a single table in the database.  iTable is
** the page number of the root of the table.  After this routine returns,
** the root page is empty, but still exists.
**
** This routine will fail with SQLITE_LOCKED if there are any open
** read cursors on the table.  Open write cursors are moved to the
** root of the table.
*/
int sqlite3BtreeClearTable(Btree *pBt, int iTable){
  int rc;
  BtCursor *pCur;
  if( pBt->inTrans!=TRANS_WRITE ){
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }
  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
    if( pCur->pgnoRoot==(Pgno)iTable ){
      if( pCur->wrFlag==0 ) return SQLITE_LOCKED;
      moveToRoot(pCur);
    }
  }
  rc = clearDatabasePage(pBt, (Pgno)iTable, 0, 0);
  if( rc ){
    sqlite3BtreeRollback(pBt);
  }
  return rc;
}

/*
** Erase all information in a table and add the root of the table to
** the freelist.  Except, the root of the principle table (the one on
** page 1) is never added to the freelist.
**
** This routine will fail with SQLITE_LOCKED if there are any open
** cursors on the table.
**
** If AUTOVACUUM is enabled and the page at iTable is not the last
** root page in the database file, then the last root page 
** in the database file is moved into the slot formerly occupied by
** iTable and that last slot formerly occupied by the last root page
** is added to the freelist instead of iTable.  In this say, all
** root pages are kept at the beginning of the database file, which
** is necessary for AUTOVACUUM to work right.  *piMoved is set to the 
** page number that used to be the last root page in the file before
** the move.  If no page gets moved, *piMoved is set to 0.
** The last root page is recorded in meta[3] and the value of
** meta[3] is updated by this procedure.
*/
int sqlite3BtreeDropTable(Btree *pBt, int iTable, int *piMoved){
  int rc;
  MemPage *pPage = 0;

  if( pBt->inTrans!=TRANS_WRITE ){
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }

  /* It is illegal to drop a table if any cursors are open on the
  ** database. This is because in auto-vacuum mode the backend may
  ** need to move another root-page to fill a gap left by the deleted
  ** root page. If an open cursor was using this page a problem would 
  ** occur.
  */
  if( pBt->pCursor ){
    return SQLITE_LOCKED;
  }

  rc = getPage(pBt, (Pgno)iTable, &pPage);
  if( rc ) return rc;
  rc = sqlite3BtreeClearTable(pBt, iTable);
  if( rc ) return rc;

  *piMoved = 0;

  if( iTable>1 ){
#ifdef SQLITE_OMIT_AUTOVACUUM
    rc = freePage(pPage);
    releasePage(pPage);
#else
    if( pBt->autoVacuum ){
      Pgno maxRootPgno;
      rc = sqlite3BtreeGetMeta(pBt, 4, &maxRootPgno);
      if( rc!=SQLITE_OK ){
        releasePage(pPage);
        return rc;
      }

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

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

      rc = sqlite3BtreeUpdateMeta(pBt, 4, maxRootPgno);
    }else{
      rc = freePage(pPage);
      releasePage(pPage);
    }
#endif
  }else{
    /* If sqlite3BtreeDropTable was called on page 1. */
    zeroPage(pPage, PTF_INTKEY|PTF_LEAF );
    releasePage(pPage);
  }
  return rc;  
}


/*
** Read the meta-information out of a database file.  Meta[0]
** is the number of free pages currently in the database.  Meta[1]
** through meta[15] are available for use by higher layers.  Meta[0]
** is read-only, the others are read/write.
** 
** The schema layer numbers meta values differently.  At the schema
** layer (and the SetCookie and ReadCookie opcodes) the number of
** free pages is not visible.  So Cookie[0] is the same as Meta[1].
*/
int sqlite3BtreeGetMeta(Btree *pBt, int idx, u32 *pMeta){
  int rc;
  unsigned char *pP1;

  assert( idx>=0 && idx<=15 );
  rc = sqlite3pager_get(pBt->pPager, 1, (void**)&pP1);
  if( rc ) return rc;
  *pMeta = get4byte(&pP1[36 + idx*4]);
  sqlite3pager_unref(pP1);

  /* If autovacuumed is disabled in this build but we are trying to 
  ** access an autovacuumed database, then make the database readonly. 
  */
#ifdef SQLITE_OMIT_AUTOVACUUM
  if( idx==4 && *pMeta>0 ) pBt->readOnly = 1;
#endif

  return SQLITE_OK;
}

/*
** Write meta-information back into the database.  Meta[0] is
** read-only and may not be written.
*/
int sqlite3BtreeUpdateMeta(Btree *pBt, int idx, u32 iMeta){
  unsigned char *pP1;
  int rc;
  assert( idx>=1 && idx<=15 );
  if( pBt->inTrans!=TRANS_WRITE ){
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }
  assert( pBt->pPage1!=0 );
  pP1 = pBt->pPage1->aData;
  rc = sqlite3pager_write(pP1);
  if( rc ) return rc;
  put4byte(&pP1[36 + idx*4], iMeta);
  return SQLITE_OK;
}

/*
** Return the flag byte at the beginning of the page that the cursor
** is currently pointing to.
*/
int sqlite3BtreeFlags(BtCursor *pCur){
  MemPage *pPage = pCur->pPage;
  return pPage ? pPage->aData[pPage->hdrOffset] : 0;
}

#ifdef SQLITE_DEBUG
/*
** Print a disassembly of the given page on standard output.  This routine
** is used for debugging and testing only.
*/
static int btreePageDump(Btree *pBt, int pgno, int recursive, MemPage *pParent){
  int rc;
  MemPage *pPage;
  int i, j, c;
  int nFree;
  u16 idx;
  int hdr;
  int nCell;
  int isInit;
  unsigned char *data;
  char range[20];
  unsigned char payload[20];

  rc = getPage(pBt, (Pgno)pgno, &pPage);
  isInit = pPage->isInit;
  if( pPage->isInit==0 ){
    initPage(pPage, pParent);
  }
  if( rc ){
    return rc;
  }
  hdr = pPage->hdrOffset;
  data = pPage->aData;
  c = data[hdr];
  pPage->intKey = (c & (PTF_INTKEY|PTF_LEAFDATA))!=0;
  pPage->zeroData = (c & PTF_ZERODATA)!=0;
  pPage->leafData = (c & PTF_LEAFDATA)!=0;
  pPage->leaf = (c & PTF_LEAF)!=0;
  pPage->hasData = !(pPage->zeroData || (!pPage->leaf && pPage->leafData));
  nCell = get2byte(&data[hdr+3]);
  sqlite3DebugPrintf("PAGE %d:  flags=0x%02x  frag=%d   parent=%d\n", pgno,
    data[hdr], data[hdr+7], 
    (pPage->isInit && pPage->pParent) ? pPage->pParent->pgno : 0);
  assert( hdr == (pgno==1 ? 100 : 0) );
  idx = hdr + 12 - pPage->leaf*4;
  for(i=0; i<nCell; i++){
    CellInfo info;
    Pgno child;
    unsigned char *pCell;
    int sz;
    int addr;

    addr = get2byte(&data[idx + 2*i]);
    pCell = &data[addr];
    parseCellPtr(pPage, pCell, &info);
    sz = info.nSize;
    sprintf(range,"%d..%d", addr, addr+sz-1);
    if( pPage->leaf ){
      child = 0;
    }else{
      child = get4byte(pCell);
    }
    sz = info.nData;
    if( !pPage->intKey ) sz += info.nKey;
    if( sz>sizeof(payload)-1 ) sz = sizeof(payload)-1;
    memcpy(payload, &pCell[info.nHeader], sz);
    for(j=0; j<sz; j++){
      if( payload[j]<0x20 || payload[j]>0x7f ) payload[j] = '.';
    }
    payload[sz] = 0;
    sqlite3DebugPrintf(
      "cell %2d: i=%-10s chld=%-4d nk=%-4lld nd=%-4d payload=%s\n",
      i, range, child, info.nKey, info.nData, payload
    );
  }
  if( !pPage->leaf ){
    sqlite3DebugPrintf("right_child: %d\n", get4byte(&data[hdr+8]));
  }
  nFree = 0;
  i = 0;
  idx = get2byte(&data[hdr+1]);
  while( idx>0 && idx<pPage->pBt->usableSize ){
    int sz = get2byte(&data[idx+2]);
    sprintf(range,"%d..%d", idx, idx+sz-1);
    nFree += sz;
    sqlite3DebugPrintf("freeblock %2d: i=%-10s size=%-4d total=%d\n",
       i, range, sz, nFree);
    idx = get2byte(&data[idx]);
    i++;
  }
  if( idx!=0 ){
    sqlite3DebugPrintf("ERROR: next freeblock index out of range: %d\n", idx);
  }
  if( recursive && !pPage->leaf ){
    for(i=0; i<nCell; i++){
      unsigned char *pCell = findCell(pPage, i);
      btreePageDump(pBt, get4byte(pCell), 1, pPage);
      idx = get2byte(pCell);
    }
    btreePageDump(pBt, get4byte(&data[hdr+8]), 1, pPage);
  }
  pPage->isInit = isInit;
  sqlite3pager_unref(data);
  fflush(stdout);
  return SQLITE_OK;
}
int sqlite3BtreePageDump(Btree *pBt, int pgno, int recursive){
  return btreePageDump(pBt, pgno, recursive, 0);
}
#endif

#ifdef SQLITE_TEST
/*
** Fill aResult[] with information about the entry and page that the
** cursor is pointing to.
** 
**   aResult[0] =  The page number
**   aResult[1] =  The entry number
**   aResult[2] =  Total number of entries on this page
**   aResult[3] =  Cell size (local payload + header)
**   aResult[4] =  Number of free bytes on this page
**   aResult[5] =  Number of free blocks on the page
**   aResult[6] =  Total payload size (local + overflow)
**   aResult[7] =  Header size in bytes
**   aResult[8] =  Local payload size
**   aResult[9] =  Parent page number
**
** This routine is used for testing and debugging only.
*/
int sqlite3BtreeCursorInfo(BtCursor *pCur, int *aResult, int upCnt){
  int cnt, idx;
  MemPage *pPage = pCur->pPage;
  BtCursor tmpCur;

  pageIntegrity(pPage);
  assert( pPage->isInit );
  getTempCursor(pCur, &tmpCur);
  while( upCnt-- ){
    moveToParent(&tmpCur);
  }
  pPage = tmpCur.pPage;
  pageIntegrity(pPage);
  aResult[0] = sqlite3pager_pagenumber(pPage->aData);
  assert( aResult[0]==pPage->pgno );
  aResult[1] = tmpCur.idx;
  aResult[2] = pPage->nCell;
  if( tmpCur.idx>=0 && tmpCur.idx<pPage->nCell ){
    getCellInfo(&tmpCur);
    aResult[3] = tmpCur.info.nSize;
    aResult[6] = tmpCur.info.nData;
    aResult[7] = tmpCur.info.nHeader;
    aResult[8] = tmpCur.info.nLocal;
  }else{
    aResult[3] = 0;
    aResult[6] = 0;
    aResult[7] = 0;
    aResult[8] = 0;
  }
  aResult[4] = pPage->nFree;
  cnt = 0;
  idx = get2byte(&pPage->aData[pPage->hdrOffset+1]);
  while( idx>0 && idx<pPage->pBt->usableSize ){
    cnt++;
    idx = get2byte(&pPage->aData[idx]);
  }
  aResult[5] = cnt;
  if( pPage->pParent==0 || isRootPage(pPage) ){
    aResult[9] = 0;
  }else{
    aResult[9] = pPage->pParent->pgno;
  }
  releaseTempCursor(&tmpCur);
  return SQLITE_OK;
}
#endif

/*
** Return the pager associated with a BTree.  This routine is used for
** testing and debugging only.
*/
Pager *sqlite3BtreePager(Btree *pBt){
  return pBt->pPager;
}

/*
** This structure is passed around through all the sanity checking routines
** in order to keep track of some global state information.
*/
typedef struct IntegrityCk IntegrityCk;
struct IntegrityCk {
  Btree *pBt;    /* The tree being checked out */
  Pager *pPager; /* The associated pager.  Also accessible by pBt->pPager */
  int nPage;     /* Number of pages in the database */
  int *anRef;    /* Number of times each page is referenced */
  char *zErrMsg; /* An error message.  NULL of no errors seen. */
};

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/*
** Append a message to the error message string.
*/
static void checkAppendMsg(
  IntegrityCk *pCheck,
  char *zMsg1,
  const char *zFormat,
  ...
){
  va_list ap;
  char *zMsg2;
  va_start(ap, zFormat);
  zMsg2 = sqlite3VMPrintf(zFormat, ap);
  va_end(ap);
  if( zMsg1==0 ) zMsg1 = "";
  if( pCheck->zErrMsg ){
    char *zOld = pCheck->zErrMsg;
    pCheck->zErrMsg = 0;
    sqlite3SetString(&pCheck->zErrMsg, zOld, "\n", zMsg1, zMsg2, (char*)0);
    sqliteFree(zOld);
  }else{
    sqlite3SetString(&pCheck->zErrMsg, zMsg1, zMsg2, (char*)0);
  }
  sqliteFree(zMsg2);
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/*
** Add 1 to the reference count for page iPage.  If this is the second
** reference to the page, add an error message to pCheck->zErrMsg.
** Return 1 if there are 2 ore more references to the page and 0 if
** if this is the first reference to the page.
**
** Also check that the page number is in bounds.
*/
static int checkRef(IntegrityCk *pCheck, int iPage, char *zContext){
  if( iPage==0 ) return 1;
  if( iPage>pCheck->nPage || iPage<0 ){
    checkAppendMsg(pCheck, zContext, "invalid page number %d", iPage);
    return 1;
  }
  if( pCheck->anRef[iPage]==1 ){
    checkAppendMsg(pCheck, zContext, "2nd reference to page %d", iPage);
    return 1;
  }
  return  (pCheck->anRef[iPage]++)>1;
}

#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** Check that the entry in the pointer-map for page iChild maps to 
** page iParent, pointer type ptrType. If not, append an error message
** to pCheck.
*/
static void checkPtrmap(
  IntegrityCk *pCheck,   /* Integrity check context */
  Pgno iChild,           /* Child page number */
  u8 eType,              /* Expected pointer map type */
  Pgno iParent,          /* Expected pointer map parent page number */
  char *zContext         /* Context description (used for error msg) */
){
  int rc;
  u8 ePtrmapType;
  Pgno iPtrmapParent;

  rc = ptrmapGet(pCheck->pBt, iChild, &ePtrmapType, &iPtrmapParent);
  if( rc!=SQLITE_OK ){
    checkAppendMsg(pCheck, zContext, "Failed to read ptrmap key=%d", iChild);
    return;
  }

  if( ePtrmapType!=eType || iPtrmapParent!=iParent ){
    checkAppendMsg(pCheck, zContext, 
      "Bad ptr map entry key=%d expected=(%d,%d) got=(%d,%d)", 
      iChild, eType, iParent, ePtrmapType, iPtrmapParent);
  }
}
#endif

/*
** Check the integrity of the freelist or of an overflow page list.
** Verify that the number of pages on the list is N.
*/
static void checkList(
  IntegrityCk *pCheck,  /* Integrity checking context */
  int isFreeList,       /* True for a freelist.  False for overflow page list */
  int iPage,            /* Page number for first page in the list */
  int N,                /* Expected number of pages in the list */
  char *zContext        /* Context for error messages */
){
  int i;
  int expected = N;
  int iFirst = iPage;
  while( N-- > 0 ){
    unsigned char *pOvfl;
    if( iPage<1 ){
      checkAppendMsg(pCheck, zContext,
         "%d of %d pages missing from overflow list starting at %d",
          N+1, expected, iFirst);
      break;
    }
    if( checkRef(pCheck, iPage, zContext) ) break;
    if( sqlite3pager_get(pCheck->pPager, (Pgno)iPage, (void**)&pOvfl) ){
      checkAppendMsg(pCheck, zContext, "failed to get page %d", iPage);
      break;
    }
    if( isFreeList ){
      int n = get4byte(&pOvfl[4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pCheck->pBt->autoVacuum ){
        checkPtrmap(pCheck, iPage, PTRMAP_FREEPAGE, 0, zContext);
      }
#endif
      if( n>pCheck->pBt->usableSize/4-8 ){
        checkAppendMsg(pCheck, zContext,
           "freelist leaf count too big on page %d", iPage);
        N--;
      }else{
        for(i=0; i<n; i++){
          Pgno iFreePage = get4byte(&pOvfl[8+i*4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
          if( pCheck->pBt->autoVacuum ){
            checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0, zContext);
          }
#endif
          checkRef(pCheck, iFreePage, zContext);
        }
        N -= n;
      }
    }
#ifndef SQLITE_OMIT_AUTOVACUUM
    else{
      /* If this database supports auto-vacuum and iPage is not the last
      ** page in this overflow list, check that the pointer-map entry for
      ** the following page matches iPage.
      */
      if( pCheck->pBt->autoVacuum && N>0 ){
        i = get4byte(pOvfl);
        checkPtrmap(pCheck, i, PTRMAP_OVERFLOW2, iPage, zContext);
      }
    }
#endif
    iPage = get4byte(pOvfl);
    sqlite3pager_unref(pOvfl);
  }
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/*
** Do various sanity checks on a single page of a tree.  Return
** the tree depth.  Root pages return 0.  Parents of root pages
** return 1, and so forth.
** 
** These checks are done:
**
**      1.  Make sure that cells and freeblocks do not overlap
**          but combine to completely cover the page.
**  NO  2.  Make sure cell keys are in order.
**  NO  3.  Make sure no key is less than or equal to zLowerBound.
**  NO  4.  Make sure no key is greater than or equal to zUpperBound.
**      5.  Check the integrity of overflow pages.
**      6.  Recursively call checkTreePage on all children.
**      7.  Verify that the depth of all children is the same.
**      8.  Make sure this page is at least 33% full or else it is
**          the root of the tree.
*/
static int checkTreePage(
  IntegrityCk *pCheck,  /* Context for the sanity check */
  int iPage,            /* Page number of the page to check */
  MemPage *pParent,     /* Parent page */
  char *zParentContext, /* Parent context */
  char *zLowerBound,    /* All keys should be greater than this, if not NULL */
  int nLower,           /* Number of characters in zLowerBound */
  char *zUpperBound,    /* All keys should be less than this, if not NULL */
  int nUpper            /* Number of characters in zUpperBound */
){
  MemPage *pPage;
  int i, rc, depth, d2, pgno, cnt;
  int hdr, cellStart;
  int nCell;
  u8 *data;
  BtCursor cur;
  Btree *pBt;
  int maxLocal, usableSize;
  char zContext[100];
  char *hit;

  sprintf(zContext, "Page %d: ", iPage);

  /* Check that the page exists
  */
  cur.pBt = pBt = pCheck->pBt;
  usableSize = pBt->usableSize;
  if( iPage==0 ) return 0;
  if( checkRef(pCheck, iPage, zParentContext) ) return 0;
  if( (rc = getPage(pBt, (Pgno)iPage, &pPage))!=0 ){
    checkAppendMsg(pCheck, zContext,
       "unable to get the page. error code=%d", rc);
    return 0;
  }
  maxLocal = pPage->leafData ? pBt->maxLeaf : pBt->maxLocal;
  if( (rc = initPage(pPage, pParent))!=0 ){
    checkAppendMsg(pCheck, zContext, "initPage() returns error code %d", rc);
    releasePage(pPage);
    return 0;
  }

  /* Check out all the cells.
  */
  depth = 0;
  cur.pPage = pPage;
  for(i=0; i<pPage->nCell; i++){
    u8 *pCell;
    int sz;
    CellInfo info;

    /* Check payload overflow pages
    */
    sprintf(zContext, "On tree page %d cell %d: ", iPage, i);
    pCell = findCell(pPage,i);
    parseCellPtr(pPage, pCell, &info);
    sz = info.nData;
    if( !pPage->intKey ) sz += info.nKey;
    if( sz>info.nLocal ){
      int nPage = (sz - info.nLocal + usableSize - 5)/(usableSize - 4);
      Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pBt->autoVacuum ){
        checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, iPage, zContext);
      }
#endif
      checkList(pCheck, 0, pgnoOvfl, nPage, zContext);
    }

    /* Check sanity of left child page.
    */
    if( !pPage->leaf ){
      pgno = get4byte(pCell);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pBt->autoVacuum ){
        checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage, zContext);
      }
#endif
      d2 = checkTreePage(pCheck,pgno,pPage,zContext,0,0,0,0);
      if( i>0 && d2!=depth ){
        checkAppendMsg(pCheck, zContext, "Child page depth differs");
      }
      depth = d2;
    }
  }
  if( !pPage->leaf ){
    pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
    sprintf(zContext, "On page %d at right child: ", iPage);
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum ){
      checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage, 0);
    }
#endif
    checkTreePage(pCheck, pgno, pPage, zContext,0,0,0,0);
  }
 
  /* Check for complete coverage of the page
  */
  data = pPage->aData;
  hdr = pPage->hdrOffset;
  hit = sqliteMalloc( usableSize );
  if( hit ){
    memset(hit, 1, get2byte(&data[hdr+5]));
    nCell = get2byte(&data[hdr+3]);
    cellStart = hdr + 12 - 4*pPage->leaf;
    for(i=0; i<nCell; i++){
      int pc = get2byte(&data[cellStart+i*2]);
      int size = cellSizePtr(pPage, &data[pc]);
      int j;
      if( (pc+size-1)>=usableSize || pc<0 ){
        checkAppendMsg(pCheck, 0, 
            "Corruption detected in cell %d on page %d",i,iPage,0);
      }else{
        for(j=pc+size-1; j>=pc; j--) hit[j]++;
      }
    }
    for(cnt=0, i=get2byte(&data[hdr+1]); i>0 && i<usableSize && cnt<10000; 
           cnt++){
      int size = get2byte(&data[i+2]);
      int j;
      if( (i+size-1)>=usableSize || i<0 ){
        checkAppendMsg(pCheck, 0,  
            "Corruption detected in cell %d on page %d",i,iPage,0);
      }else{
        for(j=i+size-1; j>=i; j--) hit[j]++;
      }
      i = get2byte(&data[i]);
    }
    for(i=cnt=0; i<usableSize; i++){
      if( hit[i]==0 ){
        cnt++;
      }else if( hit[i]>1 ){
        checkAppendMsg(pCheck, 0,
          "Multiple uses for byte %d of page %d", i, iPage);
        break;
      }
    }
    if( cnt!=data[hdr+7] ){
      checkAppendMsg(pCheck, 0, 
          "Fragmented space is %d byte reported as %d on page %d",
          cnt, data[hdr+7], iPage);
    }
  }
  sqliteFree(hit);

  releasePage(pPage);
  return depth+1;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/*
** This routine does a complete check of the given BTree file.  aRoot[] is
** an array of pages numbers were each page number is the root page of
** a table.  nRoot is the number of entries in aRoot.
**
** If everything checks out, this routine returns NULL.  If something is
** amiss, an error message is written into memory obtained from malloc()
** and a pointer to that error message is returned.  The calling function
** is responsible for freeing the error message when it is done.
*/
char *sqlite3BtreeIntegrityCheck(Btree *pBt, int *aRoot, int nRoot){
  int i;
  int nRef;
  IntegrityCk sCheck;

  nRef = *sqlite3pager_stats(pBt->pPager);
  if( lockBtree(pBt)!=SQLITE_OK ){
    return sqliteStrDup("Unable to acquire a read lock on the database");
  }
  sCheck.pBt = pBt;
  sCheck.pPager = pBt->pPager;
  sCheck.nPage = sqlite3pager_pagecount(sCheck.pPager);
  if( sCheck.nPage==0 ){
    unlockBtreeIfUnused(pBt);
    return 0;
  }
  sCheck.anRef = sqliteMallocRaw( (sCheck.nPage+1)*sizeof(sCheck.anRef[0]) );
  if( !sCheck.anRef ){
    unlockBtreeIfUnused(pBt);
    return sqlite3MPrintf("Unable to malloc %d bytes", 
        (sCheck.nPage+1)*sizeof(sCheck.anRef[0]));
  }
  for(i=0; i<=sCheck.nPage; i++){ sCheck.anRef[i] = 0; }
  i = PENDING_BYTE_PAGE(pBt);
  if( i<=sCheck.nPage ){
    sCheck.anRef[i] = 1;
  }
  sCheck.zErrMsg = 0;

  /* Check the integrity of the freelist
  */
  checkList(&sCheck, 1, get4byte(&pBt->pPage1->aData[32]),
            get4byte(&pBt->pPage1->aData[36]), "Main freelist: ");

  /* Check all the tables.
  */
  for(i=0; i<nRoot; i++){
    if( aRoot[i]==0 ) continue;
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum && aRoot[i]>1 ){
      checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0, 0);
    }
#endif
    checkTreePage(&sCheck, aRoot[i], 0, "List of tree roots: ", 0,0,0,0);
  }

  /* Make sure every page in the file is referenced
  */
  for(i=1; i<=sCheck.nPage; i++){
#ifdef SQLITE_OMIT_AUTOVACUUM
    if( sCheck.anRef[i]==0 ){
      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
    }
#else
    /* If the database supports auto-vacuum, make sure no tables contain
    ** references to pointer-map pages.
    */
    if( sCheck.anRef[i]==0 && 
       (PTRMAP_PAGENO(pBt->usableSize, i)!=i || !pBt->autoVacuum) ){
      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
    }
    if( sCheck.anRef[i]!=0 && 
       (PTRMAP_PAGENO(pBt->usableSize, i)==i && pBt->autoVacuum) ){
      checkAppendMsg(&sCheck, 0, "Pointer map page %d is referenced", i);
    }
#endif
  }

  /* Make sure this analysis did not leave any unref() pages
  */
  unlockBtreeIfUnused(pBt);
  if( nRef != *sqlite3pager_stats(pBt->pPager) ){
    checkAppendMsg(&sCheck, 0, 
      "Outstanding page count goes from %d to %d during this analysis",
      nRef, *sqlite3pager_stats(pBt->pPager)
    );
  }

  /* Clean  up and report errors.
  */
  sqliteFree(sCheck.anRef);
  return sCheck.zErrMsg;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

/*
** Return the full pathname of the underlying database file.
*/
const char *sqlite3BtreeGetFilename(Btree *pBt){
  assert( pBt->pPager!=0 );
  return sqlite3pager_filename(pBt->pPager);
}

/*
** Return the pathname of the directory that contains the database file.
*/
const char *sqlite3BtreeGetDirname(Btree *pBt){
  assert( pBt->pPager!=0 );
  return sqlite3pager_dirname(pBt->pPager);
}

/*
** Return the pathname of the journal file for this database. The return
** value of this routine is the same regardless of whether the journal file
** has been created or not.
*/
const char *sqlite3BtreeGetJournalname(Btree *pBt){
  assert( pBt->pPager!=0 );
  return sqlite3pager_journalname(pBt->pPager);
}

#ifndef SQLITE_OMIT_VACUUM
/*
** Copy the complete content of pBtFrom into pBtTo.  A transaction
** must be active for both files.
**
** The size of file pBtFrom may be reduced by this operation.
** If anything goes wrong, the transaction on pBtFrom is rolled back.
*/
int sqlite3BtreeCopyFile(Btree *pBtTo, Btree *pBtFrom){
  int rc = SQLITE_OK;
  Pgno i, nPage, nToPage;

  if( pBtTo->inTrans!=TRANS_WRITE || pBtFrom->inTrans!=TRANS_WRITE ){
    return SQLITE_ERROR;
  }
  if( pBtTo->pCursor ) return SQLITE_BUSY;
  nToPage = sqlite3pager_pagecount(pBtTo->pPager);
  nPage = sqlite3pager_pagecount(pBtFrom->pPager);
  for(i=1; rc==SQLITE_OK && i<=nPage; i++){
    void *pPage;
    rc = sqlite3pager_get(pBtFrom->pPager, i, &pPage);
    if( rc ) break;
    rc = sqlite3pager_overwrite(pBtTo->pPager, i, pPage);
    if( rc ) break;
    sqlite3pager_unref(pPage);
  }
  for(i=nPage+1; rc==SQLITE_OK && i<=nToPage; i++){
    void *pPage;
    rc = sqlite3pager_get(pBtTo->pPager, i, &pPage);
    if( rc ) break;
    rc = sqlite3pager_write(pPage);
    sqlite3pager_unref(pPage);
    sqlite3pager_dont_write(pBtTo->pPager, i);
  }
  if( !rc && nPage<nToPage ){
    rc = sqlite3pager_truncate(pBtTo->pPager, nPage);
  }
  if( rc ){
    sqlite3BtreeRollback(pBtTo);
  }
  return rc;  
}
#endif /* SQLITE_OMIT_VACUUM */

/*
** Return non-zero if a transaction is active.
*/
int sqlite3BtreeIsInTrans(Btree *pBt){
  return (pBt && (pBt->inTrans==TRANS_WRITE));
}

/*
** Return non-zero if a statement transaction is active.
*/
int sqlite3BtreeIsInStmt(Btree *pBt){
  return (pBt && pBt->inStmt);
}

/*
** This call is a no-op if no write-transaction is currently active on pBt.
**
** Otherwise, sync the database file for the btree pBt. zMaster points to
** the name of a master journal file that should be written into the
** individual journal file, or is NULL, indicating no master journal file 
** (single database transaction).
**
** When this is called, the master journal should already have been
** created, populated with this journal pointer and synced to disk.
**
** Once this is routine has returned, the only thing required to commit
** the write-transaction for this database file is to delete the journal.
*/
int sqlite3BtreeSync(Btree *pBt, const char *zMaster){
  if( pBt->inTrans==TRANS_WRITE ){
#ifndef SQLITE_OMIT_AUTOVACUUM
    Pgno nTrunc = 0;
    if( pBt->autoVacuum ){
      int rc = autoVacuumCommit(pBt, &nTrunc); 
      if( rc!=SQLITE_OK ) return rc;
    }
    return sqlite3pager_sync(pBt->pPager, zMaster, nTrunc);
#endif
    return sqlite3pager_sync(pBt->pPager, zMaster, 0);
  }
  return SQLITE_OK;
}

Added SQLite.Interop/src/btree.h.





























































































































































































































































































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/*
** 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.
**
** @(#) $Id: btree.h,v 1.1 2005/03/01 16:04:27 rmsimpson Exp $
*/
#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

/*
** Forward declarations of structure
*/
typedef struct Btree Btree;
typedef struct BtCursor BtCursor;


int sqlite3BtreeOpen(
  const char *zFilename,   /* Name of database file to open */
  Btree **,                /* Return open Btree* here */
  int flags                /* Flags */
);

/* 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 use journal.  No argument */
#define BTREE_NO_READLOCK   2  /* Omit readlocks on readonly files */
#define BTREE_MEMORY        4  /* In-memory DB.  No argument */

int sqlite3BtreeClose(Btree*);
int sqlite3BtreeSetBusyHandler(Btree*,BusyHandler*);
int sqlite3BtreeSetCacheSize(Btree*,int);
int sqlite3BtreeSetSafetyLevel(Btree*,int);
int sqlite3BtreeSetPageSize(Btree*,int,int);
int sqlite3BtreeGetPageSize(Btree*);
int sqlite3BtreeGetReserve(Btree*);
int sqlite3BtreeSetAutoVacuum(Btree *, int);
int sqlite3BtreeGetAutoVacuum(Btree *);
int sqlite3BtreeBeginTrans(Btree*,int);
int sqlite3BtreeCommit(Btree*);
int sqlite3BtreeRollback(Btree*);
int sqlite3BtreeBeginStmt(Btree*);
int sqlite3BtreeCommitStmt(Btree*);
int sqlite3BtreeRollbackStmt(Btree*);
int sqlite3BtreeCreateTable(Btree*, int*, int flags);
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInStmt(Btree*);
int sqlite3BtreeSync(Btree*, const char *zMaster);

const char *sqlite3BtreeGetFilename(Btree *);
const char *sqlite3BtreeGetDirname(Btree *);
const char *sqlite3BtreeGetJournalname(Btree *);
int sqlite3BtreeCopyFile(Btree *, Btree *);

/* The flags parameter to sqlite3BtreeCreateTable can be the bitwise OR
** of the following flags:
*/
#define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */
#define BTREE_ZERODATA   2    /* Table has keys only - no data */
#define BTREE_LEAFDATA   4    /* Data stored in leaves only.  Implies INTKEY */

int sqlite3BtreeDropTable(Btree*, int, int*);
int sqlite3BtreeClearTable(Btree*, int);
int sqlite3BtreeGetMeta(Btree*, int idx, u32 *pValue);
int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);

int sqlite3BtreeCursor(
  Btree*,                              /* BTree containing table to open */
  int iTable,                          /* Index of root page */
  int wrFlag,                          /* 1 for writing.  0 for read-only */
  int(*)(void*,int,const void*,int,const void*),  /* Key comparison function */
  void*,                               /* First argument to compare function */
  BtCursor **ppCursor                  /* Returned cursor */
);

void sqlite3BtreeSetCompare(
  BtCursor *,
  int(*)(void*,int,const void*,int,const void*),
  void*
);

int sqlite3BtreeCloseCursor(BtCursor*);
int sqlite3BtreeMoveto(BtCursor*, const void *pKey, i64 nKey, int *pRes);
int sqlite3BtreeDelete(BtCursor*);
int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
                                  const void *pData, int nData);
int sqlite3BtreeFirst(BtCursor*, int *pRes);
int sqlite3BtreeLast(BtCursor*, int *pRes);
int sqlite3BtreeNext(BtCursor*, int *pRes);
int sqlite3BtreeEof(BtCursor*);
int sqlite3BtreeFlags(BtCursor*);
int sqlite3BtreePrevious(BtCursor*, int *pRes);
int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt);
const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);

char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot);
struct Pager *sqlite3BtreePager(Btree*);


#ifdef SQLITE_TEST
int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
void sqlite3BtreeCursorList(Btree*);
#endif

#ifdef SQLITE_DEBUG
int sqlite3BtreePageDump(Btree*, int, int recursive);
#else
#define sqlite3BtreePageDump(X,Y,Z) SQLITE_OK
#endif

#endif /* _BTREE_H_ */

Added SQLite.Interop/src/build.c.












































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































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/*
** 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 file contains C code routines that are called by the SQLite parser
** when syntax rules are reduced.  The routines in this file handle the
** following kinds of SQL syntax:
**
**     CREATE TABLE
**     DROP TABLE
**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.1 2005/03/01 16:04:28 rmsimpson Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

/*
** This routine is called after a single SQL statement has been
** parsed and a VDBE program to execute that statement has been
** prepared.  This routine puts the finishing touches on the
** VDBE program and resets the pParse structure for the next
** parse.
**
** Note that if an error occurred, it might be the case that
** no VDBE code was generated.
*/
void sqlite3FinishCoding(Parse *pParse){
  sqlite3 *db;
  Vdbe *v;

  if( sqlite3_malloc_failed ) return;
  if( pParse->nested ) return;
  if( !pParse->pVdbe ){
    if( pParse->rc==SQLITE_OK && pParse->nErr ){
      pParse->rc = SQLITE_ERROR;
    }
    return;
  }

  /* Begin by generating some termination code at the end of the
  ** vdbe program
  */
  db = pParse->db;
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_Halt, 0, 0);

    /* The cookie mask contains one bit for each database file open.
    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
    ** set for each database that is used.  Generate code to start a
    ** transaction on each used database and to verify the schema cookie
    ** on each used database.
    */
    if( pParse->cookieGoto>0 ){
      u32 mask;
      int iDb;
      sqlite3VdbeChangeP2(v, pParse->cookieGoto-1, sqlite3VdbeCurrentAddr(v));
      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
        if( (mask & pParse->cookieMask)==0 ) continue;
        sqlite3VdbeAddOp(v, OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
        sqlite3VdbeAddOp(v, OP_VerifyCookie, iDb, pParse->cookieValue[iDb]);
      }
      sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->cookieGoto);
    }

    /* Add a No-op that contains the complete text of the compiled SQL
    ** statement as its P3 argument.  This does not change the functionality
    ** of the program. 
    **
    ** This is used to implement sqlite3_trace().
    */
    sqlite3VdbeOp3(v, OP_Noop, 0, 0, pParse->zSql, pParse->zTail-pParse->zSql);
  }


  /* Get the VDBE program ready for execution
  */
  if( v && pParse->nErr==0 ){
    FILE *trace = (db->flags & SQLITE_VdbeTrace)!=0 ? stdout : 0;
    sqlite3VdbeTrace(v, trace);
    sqlite3VdbeMakeReady(v, pParse->nVar, pParse->nMem+3,
                         pParse->nTab+3, pParse->nMaxDepth+1, pParse->explain);
    pParse->rc = SQLITE_DONE;
    pParse->colNamesSet = 0;
  }else if( pParse->rc==SQLITE_OK ){
    pParse->rc = SQLITE_ERROR;
  }
  pParse->nTab = 0;
  pParse->nMem = 0;
  pParse->nSet = 0;
  pParse->nVar = 0;
  pParse->cookieMask = 0;
  pParse->cookieGoto = 0;
}

/*
** Run the parser and code generator recursively in order to generate
** code for the SQL statement given onto the end of the pParse context
** currently under construction.  When the parser is run recursively
** this way, the final OP_Halt is not appended and other initialization
** and finalization steps are omitted because those are handling by the
** outermost parser.
**
** Not everything is nestable.  This facility is designed to permit
** INSERT, UPDATE, and DELETE operations against SQLITE_MASTER.  Use
** care if you decide to try to use this routine for some other purposes.
*/
void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
  va_list ap;
  char *zSql;
  int rc;
# define SAVE_SZ  (sizeof(Parse) - offsetof(Parse,nVar))
  char saveBuf[SAVE_SZ];

  if( pParse->nErr ) return;
  assert( pParse->nested<10 );  /* Nesting should only be of limited depth */
  va_start(ap, zFormat);
  zSql = sqlite3VMPrintf(zFormat, ap);
  va_end(ap);
  if( zSql==0 ){
    return;   /* A malloc must have failed */
  }
  pParse->nested++;
  memcpy(saveBuf, &pParse->nVar, SAVE_SZ);
  memset(&pParse->nVar, 0, SAVE_SZ);
  rc = sqlite3RunParser(pParse, zSql, 0);
  sqliteFree(zSql);
  memcpy(&pParse->nVar, saveBuf, SAVE_SZ);
  pParse->nested--;
}

/*
** Locate the in-memory structure that describes a particular database
** table given the name of that table and (optionally) the name of the
** database containing the table.  Return NULL if not found.
**
** If zDatabase is 0, all databases are searched for the table and the
** first matching table is returned.  (No checking for duplicate table
** names is done.)  The search order is TEMP first, then MAIN, then any
** auxiliary databases added using the ATTACH command.
**
** See also sqlite3LocateTable().
*/
Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
  Table *p = 0;
  int i;
  assert( zName!=0 );
  assert( (db->flags & SQLITE_Initialized) || db->init.busy );
  for(i=0; i<db->nDb; i++){
    int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */
    if( zDatabase!=0 && sqlite3StrICmp(zDatabase, db->aDb[j].zName) ) continue;
    p = sqlite3HashFind(&db->aDb[j].tblHash, zName, strlen(zName)+1);
    if( p ) break;
  }
  return p;
}

/*
** Locate the in-memory structure that describes a particular database
** table given the name of that table and (optionally) the name of the
** database containing the table.  Return NULL if not found.  Also leave an
** error message in pParse->zErrMsg.
**
** The difference between this routine and sqlite3FindTable() is that this
** routine leaves an error message in pParse->zErrMsg where
** sqlite3FindTable() does not.
*/
Table *sqlite3LocateTable(Parse *pParse, const char *zName, const char *zDbase){
  Table *p;

  /* Read the database schema. If an error occurs, leave an error message
  ** and code in pParse and return NULL. */
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    return 0;
  }

  p = sqlite3FindTable(pParse->db, zName, zDbase);
  if( p==0 ){
    if( zDbase ){
      sqlite3ErrorMsg(pParse, "no such table: %s.%s", zDbase, zName);
    }else if( sqlite3FindTable(pParse->db, zName, 0)!=0 ){
      sqlite3ErrorMsg(pParse, "table \"%s\" is not in database \"%s\"",
         zName, zDbase);
    }else{
      sqlite3ErrorMsg(pParse, "no such table: %s", zName);
    }
    pParse->checkSchema = 1;
  }
  return p;
}

/*
** Locate the in-memory structure that describes 
** a particular index given the name of that index
** and the name of the database that contains the index.
** Return NULL if not found.
**
** If zDatabase is 0, all databases are searched for the
** table and the first matching index is returned.  (No checking
** for duplicate index names is done.)  The search order is
** TEMP first, then MAIN, then any auxiliary databases added
** using the ATTACH command.
*/
Index *sqlite3FindIndex(sqlite3 *db, const char *zName, const char *zDb){
  Index *p = 0;
  int i;
  assert( (db->flags & SQLITE_Initialized) || db->init.busy );
  for(i=0; i<db->nDb; i++){
    int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
    if( zDb && sqlite3StrICmp(zDb, db->aDb[j].zName) ) continue;
    p = sqlite3HashFind(&db->aDb[j].idxHash, zName, strlen(zName)+1);
    if( p ) break;
  }
  return p;
}

/*
** Reclaim the memory used by an index
*/
static void freeIndex(Index *p){
  sqliteFree(p->zColAff);
  sqliteFree(p);
}

/*
** Remove the given index from the index hash table, and free
** its memory structures.
**
** The index is removed from the database hash tables but
** it is not unlinked from the Table that it indexes.
** Unlinking from the Table must be done by the calling function.
*/
static void sqliteDeleteIndex(sqlite3 *db, Index *p){
  Index *pOld;

  assert( db!=0 && p->zName!=0 );
  pOld = sqlite3HashInsert(&db->aDb[p->iDb].idxHash, p->zName,
                          strlen(p->zName)+1, 0);
  if( pOld!=0 && pOld!=p ){
    sqlite3HashInsert(&db->aDb[p->iDb].idxHash, pOld->zName,
                     strlen(pOld->zName)+1, pOld);
  }
  freeIndex(p);
}

/*
** Unlink the given index from its table, then remove
** the index from the index hash table and free its memory
** structures.
*/
void sqlite3UnlinkAndDeleteIndex(sqlite3 *db, int iDb, const char *zIdxName){
  Index *pIndex;
  int len;

  len = strlen(zIdxName);
  pIndex = sqlite3HashInsert(&db->aDb[iDb].idxHash, zIdxName, len+1, 0);
  if( pIndex ){
    if( pIndex->pTable->pIndex==pIndex ){
      pIndex->pTable->pIndex = pIndex->pNext;
    }else{
      Index *p;
      for(p=pIndex->pTable->pIndex; p && p->pNext!=pIndex; p=p->pNext){}
      if( p && p->pNext==pIndex ){
        p->pNext = pIndex->pNext;
      }
    }
    freeIndex(pIndex);
  }
  db->flags |= SQLITE_InternChanges;
}

/*
** Erase all schema information from the in-memory hash tables of
** a single database.  This routine is called to reclaim memory
** before the database closes.  It is also called during a rollback
** if there were schema changes during the transaction or if a
** schema-cookie mismatch occurs.
**
** If iDb<=0 then reset the internal schema tables for all database
** files.  If iDb>=2 then reset the internal schema for only the
** single file indicated.
*/
void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
  HashElem *pElem;
  Hash temp1;
  Hash temp2;
  int i, j;

  assert( iDb>=0 && iDb<db->nDb );
  db->flags &= ~SQLITE_Initialized;
  for(i=iDb; i<db->nDb; i++){
    Db *pDb = &db->aDb[i];
    temp1 = pDb->tblHash;
    temp2 = pDb->trigHash;
    sqlite3HashInit(&pDb->trigHash, SQLITE_HASH_STRING, 0);
    sqlite3HashClear(&pDb->aFKey);
    sqlite3HashClear(&pDb->idxHash);
    for(pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){
      sqlite3DeleteTrigger((Trigger*)sqliteHashData(pElem));
    }
    sqlite3HashClear(&temp2);
    sqlite3HashInit(&pDb->tblHash, SQLITE_HASH_STRING, 0);
    for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
      Table *pTab = sqliteHashData(pElem);
      sqlite3DeleteTable(db, pTab);
    }
    sqlite3HashClear(&temp1);
    pDb->pSeqTab = 0;
    DbClearProperty(db, i, DB_SchemaLoaded);
    if( iDb>0 ) return;
  }
  assert( iDb==0 );
  db->flags &= ~SQLITE_InternChanges;

  /* If one or more of the auxiliary database files has been closed,
  ** then remove then from the auxiliary database list.  We take the
  ** opportunity to do this here since we have just deleted all of the
  ** schema hash tables and therefore do not have to make any changes
  ** to any of those tables.
  */
  for(i=0; i<db->nDb; i++){
    struct Db *pDb = &db->aDb[i];
    if( pDb->pBt==0 ){
      if( pDb->pAux && pDb->xFreeAux ) pDb->xFreeAux(pDb->pAux);
      pDb->pAux = 0;
    }
  }
  for(i=j=2; i<db->nDb; i++){
    struct Db *pDb = &db->aDb[i];
    if( pDb->pBt==0 ){
      sqliteFree(pDb->zName);
      pDb->zName = 0;
      continue;
    }
    if( j<i ){
      db->aDb[j] = db->aDb[i];
    }
    j++;
  }
  memset(&db->aDb[j], 0, (db->nDb-j)*sizeof(db->aDb[j]));
  db->nDb = j;
  if( db->nDb<=2 && db->aDb!=db->aDbStatic ){
    memcpy(db->aDbStatic, db->aDb, 2*sizeof(db->aDb[0]));
    sqliteFree(db->aDb);
    db->aDb = db->aDbStatic;
  }
}

/*
** This routine is called whenever a rollback occurs.  If there were
** schema changes during the transaction, then we have to reset the
** internal hash tables and reload them from disk.
*/
void sqlite3RollbackInternalChanges(sqlite3 *db){
  if( db->flags & SQLITE_InternChanges ){
    sqlite3ResetInternalSchema(db, 0);
  }
}

/*
** This routine is called when a commit occurs.
*/
void sqlite3CommitInternalChanges(sqlite3 *db){
  db->flags &= ~SQLITE_InternChanges;
}

/*
** Clear the column names from a table or view.
*/
static void sqliteResetColumnNames(Table *pTable){
  int i;
  Column *pCol;
  assert( pTable!=0 );
  for(i=0, pCol=pTable->aCol; i<pTable->nCol; i++, pCol++){
    sqliteFree(pCol->zName);
    sqlite3ExprDelete(pCol->pDflt);
    sqliteFree(pCol->zType);
  }
  sqliteFree(pTable->aCol);
  pTable->aCol = 0;
  pTable->nCol = 0;
}

/*
** Remove the memory data structures associated with the given
** Table.  No changes are made to disk by this routine.
**
** This routine just deletes the data structure.  It does not unlink
** the table data structure from the hash table.  Nor does it remove
** foreign keys from the sqlite.aFKey hash table.  But it does destroy
** memory structures of the indices and foreign keys associated with 
** the table.
**
** Indices associated with the table are unlinked from the "db"
** data structure if db!=NULL.  If db==NULL, indices attached to
** the table are deleted, but it is assumed they have already been
** unlinked.
*/
void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
  Index *pIndex, *pNext;
  FKey *pFKey, *pNextFKey;

  if( pTable==0 ) return;

  /* Delete all indices associated with this table
  */
  for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
    pNext = pIndex->pNext;
    assert( pIndex->iDb==pTable->iDb || (pTable->iDb==0 && pIndex->iDb==1) );
    sqliteDeleteIndex(db, pIndex);
  }

#ifndef SQLITE_OMIT_FOREIGN_KEY
  /* Delete all foreign keys associated with this table.  The keys
  ** should have already been unlinked from the db->aFKey hash table 
  */
  for(pFKey=pTable->pFKey; pFKey; pFKey=pNextFKey){
    pNextFKey = pFKey->pNextFrom;
    assert( pTable->iDb<db->nDb );
    assert( sqlite3HashFind(&db->aDb[pTable->iDb].aFKey,
                           pFKey->zTo, strlen(pFKey->zTo)+1)!=pFKey );
    sqliteFree(pFKey);
  }
#endif

  /* Delete the Table structure itself.
  */
  sqliteResetColumnNames(pTable);
  sqliteFree(pTable->zName);
  sqliteFree(pTable->zColAff);
  sqlite3SelectDelete(pTable->pSelect);
  sqliteFree(pTable);
}

/*
** Unlink the given table from the hash tables and the delete the
** table structure with all its indices and foreign keys.
*/
void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char *zTabName){
  Table *p;
  FKey *pF1, *pF2;
  Db *pDb;

  assert( db!=0 );
  assert( iDb>=0 && iDb<db->nDb );
  assert( zTabName && zTabName[0] );
  pDb = &db->aDb[iDb];
  p = sqlite3HashInsert(&pDb->tblHash, zTabName, strlen(zTabName)+1, 0);
  if( p ){
#ifndef SQLITE_OMIT_FOREIGN_KEY
    for(pF1=p->pFKey; pF1; pF1=pF1->pNextFrom){
      int nTo = strlen(pF1->zTo) + 1;
      pF2 = sqlite3HashFind(&pDb->aFKey, pF1->zTo, nTo);
      if( pF2==pF1 ){
        sqlite3HashInsert(&pDb->aFKey, pF1->zTo, nTo, pF1->pNextTo);
      }else{
        while( pF2 && pF2->pNextTo!=pF1 ){ pF2=pF2->pNextTo; }
        if( pF2 ){
          pF2->pNextTo = pF1->pNextTo;
        }
      }
    }
#endif
    sqlite3DeleteTable(db, p);
  }
  db->flags |= SQLITE_InternChanges;
}

/*
** Given a token, return a string that consists of the text of that
** token with any quotations removed.  Space to hold the returned string
** is obtained from sqliteMalloc() and must be freed by the calling
** function.
**
** Tokens are really just pointers into the original SQL text and so
** are not \000 terminated and are not persistent.  The returned string
** is \000 terminated and is persistent.
*/
char *sqlite3NameFromToken(Token *pName){
  char *zName;
  if( pName ){
    zName = sqliteStrNDup(pName->z, pName->n);
    sqlite3Dequote(zName);
  }else{
    zName = 0;
  }
  return zName;
}

/*
** Open the sqlite_master table stored in database number iDb for
** writing. The table is opened using cursor 0.
*/
void sqlite3OpenMasterTable(Vdbe *v, int iDb){
  sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
  sqlite3VdbeAddOp(v, OP_OpenWrite, 0, MASTER_ROOT);
  sqlite3VdbeAddOp(v, OP_SetNumColumns, 0, 5); /* sqlite_master has 5 columns */
}

/*
** The token *pName contains the name of a database (either "main" or
** "temp" or the name of an attached db). This routine returns the
** index of the named database in db->aDb[], or -1 if the named db 
** does not exist.
*/
static int findDb(sqlite3 *db, Token *pName){
  int i = -1;    /* Database number */
  int n;         /* Number of characters in the name */
  Db *pDb;       /* A database whose name space is being searched */
  char *zName;   /* Name we are searching for */

  zName = sqlite3NameFromToken(pName);
  if( zName ){
    n = strlen(zName);
    for(i=(db->nDb-1), pDb=&db->aDb[i]; i>=0; i--, pDb--){
      if( n==strlen(pDb->zName) && 0==sqlite3StrICmp(pDb->zName, zName) ){
        break;
      }
    }
    sqliteFree(zName);
  }
  return i;
}

/* The table or view or trigger name is passed to this routine via tokens
** pName1 and pName2. If the table name was fully qualified, for example:
**
** CREATE TABLE xxx.yyy (...);
** 
** Then pName1 is set to "xxx" and pName2 "yyy". On the other hand if
** the table name is not fully qualified, i.e.:
**
** CREATE TABLE yyy(...);
**
** Then pName1 is set to "yyy" and pName2 is "".
**
** This routine sets the *ppUnqual pointer to point at the token (pName1 or
** pName2) that stores the unqualified table name.  The index of the
** database "xxx" is returned.
*/
int sqlite3TwoPartName(
  Parse *pParse,      /* Parsing and code generating context */
  Token *pName1,      /* The "xxx" in the name "xxx.yyy" or "xxx" */
  Token *pName2,      /* The "yyy" in the name "xxx.yyy" */
  Token **pUnqual     /* Write the unqualified object name here */
){
  int iDb;                    /* Database holding the object */
  sqlite3 *db = pParse->db;

  if( pName2 && pName2->n>0 ){
    assert( !db->init.busy );
    *pUnqual = pName2;
    iDb = findDb(db, pName1);
    if( iDb<0 ){
      sqlite3ErrorMsg(pParse, "unknown database %T", pName1);
      pParse->nErr++;
      return -1;
    }
  }else{
    assert( db->init.iDb==0 || db->init.busy );
    iDb = db->init.iDb;
    *pUnqual = pName1;
  }
  return iDb;
}

/*
** This routine is used to check if the UTF-8 string zName is a legal
** unqualified name for a new schema object (table, index, view or
** trigger). All names are legal except those that begin with the string
** "sqlite_" (in upper, lower or mixed case). This portion of the namespace
** is reserved for internal use.
*/
int sqlite3CheckObjectName(Parse *pParse, const char *zName){
  if( !pParse->db->init.busy && pParse->nested==0 
          && 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){
    sqlite3ErrorMsg(pParse, "object name reserved for internal use: %s", zName);
    return SQLITE_ERROR;
  }
  return SQLITE_OK;
}

/*
** Begin constructing a new table representation in memory.  This is
** the first of several action routines that get called in response
** to a CREATE TABLE statement.  In particular, this routine is called
** after seeing tokens "CREATE" and "TABLE" and the table name.  The
** pStart token is the CREATE and pName is the table name.  The isTemp
** flag is true if the table should be stored in the auxiliary database
** file instead of in the main database file.  This is normally the case
** when the "TEMP" or "TEMPORARY" keyword occurs in between
** CREATE and TABLE.
**
** The new table record is initialized and put in pParse->pNewTable.
** As more of the CREATE TABLE statement is parsed, additional action
** routines will be called to add more information to this record.
** At the end of the CREATE TABLE statement, the sqlite3EndTable() routine
** is called to complete the construction of the new table record.
*/
void sqlite3StartTable(
  Parse *pParse,   /* Parser context */
  Token *pStart,   /* The "CREATE" token */
  Token *pName1,   /* First part of the name of the table or view */
  Token *pName2,   /* Second part of the name of the table or view */
  int isTemp,      /* True if this is a TEMP table */
  int isView       /* True if this is a VIEW */
){
  Table *pTable;
  Index *pIdx;
  char *zName = 0; /* The name of the new table */
  sqlite3 *db = pParse->db;
  Vdbe *v;
  int iDb;         /* Database number to create the table in */
  Token *pName;    /* Unqualified name of the table to create */

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

  pParse->sNameToken = *pName;
  zName = sqlite3NameFromToken(pName);
  if( zName==0 ) return;
  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
    goto begin_table_error;
  }
  if( db->init.iDb==1 ) isTemp = 1;
#ifndef SQLITE_OMIT_AUTHORIZATION
  assert( (isTemp & 1)==isTemp );
  {
    int code;
    char *zDb = db->aDb[iDb].zName;
    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
      goto begin_table_error;
    }
    if( isView ){
      if( isTemp ){
        code = SQLITE_CREATE_TEMP_VIEW;
      }else{
        code = SQLITE_CREATE_VIEW;
      }
    }else{
      if( isTemp ){
        code = SQLITE_CREATE_TEMP_TABLE;
      }else{
        code = SQLITE_CREATE_TABLE;
      }
    }
    if( sqlite3AuthCheck(pParse, code, zName, 0, zDb) ){
      goto begin_table_error;
    }
  }
#endif

  /* Make sure the new table name does not collide with an existing
  ** index or table name in the same database.  Issue an error message if
  ** it does.
  */
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    goto begin_table_error;
  }
  pTable = sqlite3FindTable(db, zName, db->aDb[iDb].zName);
  if( pTable ){
    sqlite3ErrorMsg(pParse, "table %T already exists", pName);
    goto begin_table_error;
  }
  if( (pIdx = sqlite3FindIndex(db, zName, 0))!=0 && 
      ( iDb==0 || !db->init.busy) ){
    sqlite3ErrorMsg(pParse, "there is already an index named %s", zName);
    goto begin_table_error;
  }
  pTable = sqliteMalloc( sizeof(Table) );
  if( pTable==0 ){
    pParse->rc = SQLITE_NOMEM;
    pParse->nErr++;
    goto begin_table_error;
  }
  pTable->zName = zName;
  pTable->nCol = 0;
  pTable->aCol = 0;
  pTable->iPKey = -1;
  pTable->pIndex = 0;
  pTable->iDb = iDb;
  if( pParse->pNewTable ) sqlite3DeleteTable(db, pParse->pNewTable);
  pParse->pNewTable = pTable;

  /* If this is the magic sqlite_sequence table used by autoincrement,
  ** then record a pointer to this table in the main database structure
  ** so that INSERT can find the table easily.
  */
#ifndef SQLITE_OMIT_AUTOINCREMENT
  if( strcmp(zName, "sqlite_sequence")==0 ){
    db->aDb[iDb].pSeqTab = pTable;
  }
#endif

  /* Begin generating the code that will insert the table record into
  ** the SQLITE_MASTER table.  Note in particular that we must go ahead
  ** and allocate the record number for the table entry now.  Before any
  ** PRIMARY KEY or UNIQUE keywords are parsed.  Those keywords will cause
  ** indices to be created and the table record must come before the 
  ** indices.  Hence, the record number for the table must be allocated
  ** now.
  */
  if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
    int lbl;
    sqlite3BeginWriteOperation(pParse, 0, iDb);

    /* If the file format and encoding in the database have not been set, 
    ** set them now.
    */
    sqlite3VdbeAddOp(v, OP_ReadCookie, iDb, 1);   /* file_format */
    lbl = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_If, 0, lbl);
    sqlite3VdbeAddOp(v, OP_Integer, db->file_format, 0);
    sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 1);
    sqlite3VdbeAddOp(v, OP_Integer, db->enc, 0);
    sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 4);
    sqlite3VdbeResolveLabel(v, lbl);

    /* This just creates a place-holder record in the sqlite_master table.
    ** The record created does not contain anything yet.  It will be replaced
    ** by the real entry in code generated at sqlite3EndTable().
    **
    ** The rowid for the new entry is left on the top of the stack.
    ** The rowid value is needed by the code that sqlite3EndTable will
    ** generate.
    */
#ifndef SQLITE_OMIT_VIEW
    if( isView ){
      sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
    }else
#endif
    {
      sqlite3VdbeAddOp(v, OP_CreateTable, iDb, 0);
    }
    sqlite3OpenMasterTable(v, iDb);
    sqlite3VdbeAddOp(v, OP_NewRecno, 0, 0);
    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
    sqlite3VdbeAddOp(v, OP_String8, 0, 0);
    sqlite3VdbeAddOp(v, OP_PutIntKey, 0, 0);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
  }

  /* Normal (non-error) return. */
  return;

  /* If an error occurs, we jump here */
begin_table_error:
  sqliteFree(zName);
  return;
}

/*
** This macro is used to compare two strings in a case-insensitive manner.
** It is slightly faster than calling sqlite3StrICmp() directly, but
** produces larger code.
**
** WARNING: This macro is not compatible with the strcmp() family. It
** returns true if the two strings are equal, otherwise false.
*/
#define STRICMP(x, y) (\
sqlite3UpperToLower[*(unsigned char *)(x)]==   \
sqlite3UpperToLower[*(unsigned char *)(y)]     \
&& sqlite3StrICmp((x)+1,(y)+1)==0 )

/*
** Add a new column to the table currently being constructed.
**
** The parser calls this routine once for each column declaration
** in a CREATE TABLE statement.  sqlite3StartTable() gets called
** first to get things going.  Then this routine is called for each
** column.
*/
void sqlite3AddColumn(Parse *pParse, Token *pName){
  Table *p;
  int i;
  char *z;
  Column *pCol;
  if( (p = pParse->pNewTable)==0 ) return;
  z = sqlite3NameFromToken(pName);
  if( z==0 ) return;
  for(i=0; i<p->nCol; i++){
    if( STRICMP(z, p->aCol[i].zName) ){
      sqlite3ErrorMsg(pParse, "duplicate column name: %s", z);
      sqliteFree(z);
      return;
    }
  }
  if( (p->nCol & 0x7)==0 ){
    Column *aNew;
    aNew = sqliteRealloc( p->aCol, (p->nCol+8)*sizeof(p->aCol[0]));
    if( aNew==0 ) return;
    p->aCol = aNew;
  }
  pCol = &p->aCol[p->nCol];
  memset(pCol, 0, sizeof(p->aCol[0]));
  pCol->zName = z;
 
  /* If there is no type specified, columns have the default affinity
  ** 'NONE'. If there is a type specified, then sqlite3AddColumnType() will
  ** be called next to set pCol->affinity correctly.
  */
  pCol->affinity = SQLITE_AFF_NONE;
  pCol->pColl = pParse->db->pDfltColl;
  p->nCol++;
}

/*
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.  A "NOT NULL" constraint has
** been seen on a column.  This routine sets the notNull flag on
** the column currently under construction.
*/
void sqlite3AddNotNull(Parse *pParse, int onError){
  Table *p;
  int i;
  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;
  if( i>=0 ) p->aCol[i].notNull = onError;
}

/*
** Scan the column type name zType (length nType) and return the
** associated affinity type.
**
** This routine does a case-independent search of zType for the 
** substrings in the following table. If one of the substrings is
** found, the corresponding affinity is returned. If zType contains
** more than one of the substrings, entries toward the top of 
** the table take priority. For example, if zType is 'BLOBINT', 
** SQLITE_AFF_INTEGER is returned.
**
** Substring     | Affinity
** --------------------------------
** 'INT'         | SQLITE_AFF_INTEGER
** 'CHAR'        | SQLITE_AFF_TEXT
** 'CLOB'        | SQLITE_AFF_TEXT
** 'TEXT'        | SQLITE_AFF_TEXT
** 'BLOB'        | SQLITE_AFF_NONE
**
** If none of the substrings in the above table are found,
** SQLITE_AFF_NUMERIC is returned.
*/
static char sqlite3AffinityType(const char *zType, int nType){
  u32 h = 0;
  char aff = SQLITE_AFF_NUMERIC;
  const unsigned char *zIn = zType;
  const unsigned char *zEnd = (zIn+nType);

  while( zIn!=zEnd ){
    h = (h<<8) + sqlite3UpperToLower[*zIn];
    zIn++;
    if( h==(('c'<<24)+('h'<<16)+('a'<<8)+'r') ){             /* CHAR */
      aff = SQLITE_AFF_TEXT; 
    }else if( h==(('c'<<24)+('l'<<16)+('o'<<8)+'b') ){       /* CLOB */
      aff = SQLITE_AFF_TEXT;
    }else if( h==(('t'<<24)+('e'<<16)+('x'<<8)+'t') ){       /* TEXT */
      aff = SQLITE_AFF_TEXT;
    }else if( h==(('b'<<24)+('l'<<16)+('o'<<8)+'b')          /* BLOB */
        && aff==SQLITE_AFF_NUMERIC ){
      aff = SQLITE_AFF_NONE;
    }else if( (h&0x00FFFFFF)==(('i'<<16)+('n'<<8)+'t') ){    /* INT */
      aff = SQLITE_AFF_INTEGER; 
      break;
    }
  }

  return aff;
}

/*
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.  The pFirst token is the first
** token in the sequence of tokens that describe the type of the
** column currently under construction.   pLast is the last token
** in the sequence.  Use this information to construct a string
** that contains the typename of the column and store that string
** in zType.
*/ 
void sqlite3AddColumnType(Parse *pParse, Token *pFirst, Token *pLast){
  Table *p;
  int i, j;
  int n;
  char *z;
  const unsigned char *zIn;

  Column *pCol;
  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;
  if( i<0 ) return;
  pCol = &p->aCol[i];
  zIn = pFirst->z;
  n = pLast->n + (pLast->z - zIn);
  assert( pCol->zType==0 );
  z = pCol->zType = sqliteMallocRaw(n+1);
  if( z==0 ) return;
  for(i=j=0; i<n; i++){
    int c = zIn[i];
    if( isspace(c) ) continue;
    z[j++] = c;
  }
  z[j] = 0;
  pCol->affinity = sqlite3AffinityType(z, n);
}

/*
** The expression is the default value for the most recently added column
** of the table currently under construction.
**
** Default value expressions must be constant.  Raise an exception if this
** is not the case.
**
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.
*/
void sqlite3AddDefaultValue(Parse *pParse, Expr *pExpr){
  Table *p;
  Column *pCol;
  if( (p = pParse->pNewTable)==0 ) return;
  pCol = &(p->aCol[p->nCol-1]);
  if( !sqlite3ExprIsConstant(pExpr) ){
    sqlite3ErrorMsg(pParse, "default value of column [%s] is not constant",
        pCol->zName);
  }else{
    sqlite3ExprDelete(pCol->pDflt);
    pCol->pDflt = sqlite3ExprDup(pExpr);
  }
  sqlite3ExprDelete(pExpr);
}

/*
** Designate the PRIMARY KEY for the table.  pList is a list of names 
** of columns that form the primary key.  If pList is NULL, then the
** most recently added column of the table is the primary key.
**
** A table can have at most one primary key.  If the table already has
** a primary key (and this is the second primary key) then create an
** error.
**
** If the PRIMARY KEY is on a single column whose datatype is INTEGER,
** then we will try to use that column as the rowid.  Set the Table.iPKey
** field of the table under construction to be the index of the
** INTEGER PRIMARY KEY column.  Table.iPKey is set to -1 if there is
** no INTEGER PRIMARY KEY.
**
** If the key is not an INTEGER PRIMARY KEY, then create a unique
** index for the key.  No index is created for INTEGER PRIMARY KEYs.
*/
void sqlite3AddPrimaryKey(
  Parse *pParse,    /* Parsing context */
  ExprList *pList,  /* List of field names to be indexed */
  int onError,      /* What to do with a uniqueness conflict */
  int autoInc       /* True if the AUTOINCREMENT keyword is present */
){
  Table *pTab = pParse->pNewTable;
  char *zType = 0;
  int iCol = -1, i;
  if( pTab==0 ) goto primary_key_exit;
  if( pTab->hasPrimKey ){
    sqlite3ErrorMsg(pParse, 
      "table \"%s\" has more than one primary key", pTab->zName);
    goto primary_key_exit;
  }
  pTab->hasPrimKey = 1;
  if( pList==0 ){
    iCol = pTab->nCol - 1;
    pTab->aCol[iCol].isPrimKey = 1;
  }else{
    for(i=0; i<pList->nExpr; i++){
      for(iCol=0; iCol<pTab->nCol; iCol++){
        if( sqlite3StrICmp(pList->a[i].zName, pTab->aCol[iCol].zName)==0 ){
          break;
        }
      }
      if( iCol<pTab->nCol ) pTab->aCol[iCol].isPrimKey = 1;
    }
    if( pList->nExpr>1 ) iCol = -1;
  }
  if( iCol>=0 && iCol<pTab->nCol ){
    zType = pTab->aCol[iCol].zType;
  }
  if( zType && sqlite3StrICmp(zType, "INTEGER")==0 ){
    pTab->iPKey = iCol;
    pTab->keyConf = onError;
    pTab->autoInc = autoInc;
  }else if( autoInc ){
#ifndef SQLITE_OMIT_AUTOINCREMENT
    sqlite3ErrorMsg(pParse, "AUTOINCREMENT is only allowed on an "
       "INTEGER PRIMARY KEY");
#endif
  }else{
    sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0, 0);
    pList = 0;
  }

primary_key_exit:
  sqlite3ExprListDelete(pList);
  return;
}

/*
** Set the collation function of the most recently parsed table column
** to the CollSeq given.
*/
void sqlite3AddCollateType(Parse *pParse, const char *zType, int nType){
  Table *p;
  Index *pIdx;
  CollSeq *pColl;
  int i;

  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;

  pColl = sqlite3LocateCollSeq(pParse, zType, nType);
  p->aCol[i].pColl = pColl;

  /* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",
  ** then an index may have been created on this column before the
  ** collation type was added. Correct this if it is the case.
  */
  for(pIdx = p->pIndex; pIdx; pIdx=pIdx->pNext){
    assert( pIdx->nColumn==1 );
    if( pIdx->aiColumn[0]==i ) pIdx->keyInfo.aColl[0] = pColl;
  }
}

/*
** Locate and return an entry from the db.aCollSeq hash table. If the entry
** specified by zName and nName is not found and parameter 'create' is
** true, then create a new entry. Otherwise return NULL.
**
** Each pointer stored in the sqlite3.aCollSeq hash table contains an
** array of three CollSeq structures. The first is the collation sequence
** prefferred for UTF-8, the second UTF-16le, and the third UTF-16be.
**
** Stored immediately after the three collation sequences is a copy of
** the collation sequence name. A pointer to this string is stored in
** each collation sequence structure.
*/
static CollSeq * findCollSeqEntry(
  sqlite3 *db,
  const char *zName,
  int nName,
  int create
){
  CollSeq *pColl;
  if( nName<0 ) nName = strlen(zName);
  pColl = sqlite3HashFind(&db->aCollSeq, zName, nName);

  if( 0==pColl && create ){
    pColl = sqliteMalloc( 3*sizeof(*pColl) + nName + 1 );
    if( pColl ){
      pColl[0].zName = (char*)&pColl[3];
      pColl[0].enc = SQLITE_UTF8;
      pColl[1].zName = (char*)&pColl[3];
      pColl[1].enc = SQLITE_UTF16LE;
      pColl[2].zName = (char*)&pColl[3];
      pColl[2].enc = SQLITE_UTF16BE;
      memcpy(pColl[0].zName, zName, nName);
      pColl[0].zName[nName] = 0;
      sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, nName, pColl);
    }
  }
  return pColl;
}

/*
** Parameter zName points to a UTF-8 encoded string nName bytes long.
** Return the CollSeq* pointer for the collation sequence named zName
** for the encoding 'enc' from the database 'db'.
**
** If the entry specified is not found and 'create' is true, then create a
** new entry.  Otherwise return NULL.
*/
CollSeq *sqlite3FindCollSeq(
  sqlite3 *db,
  u8 enc,
  const char *zName,
  int nName,
  int create
){
  CollSeq *pColl = findCollSeqEntry(db, zName, nName, create);
  assert( SQLITE_UTF8==1 && SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
  assert( enc>=SQLITE_UTF8 && enc<=SQLITE_UTF16BE );
  if( pColl ) pColl += enc-1;
  return pColl;
}

/*
** Invoke the 'collation needed' callback to request a collation sequence
** in the database text encoding of name zName, length nName.
** If the collation sequence
*/
static void callCollNeeded(sqlite3 *db, const char *zName, int nName){
  assert( !db->xCollNeeded || !db->xCollNeeded16 );
  if( nName<0 ) nName = strlen(zName);
  if( db->xCollNeeded ){
    char *zExternal = sqliteStrNDup(zName, nName);
    if( !zExternal ) return;
    db->xCollNeeded(db->pCollNeededArg, db, (int)db->enc, zExternal);
    sqliteFree(zExternal);
  }
#ifndef SQLITE_OMIT_UTF16
  if( db->xCollNeeded16 ){
    char const *zExternal;
    sqlite3_value *pTmp = sqlite3GetTransientValue(db);
    sqlite3ValueSetStr(pTmp, -1, zName, SQLITE_UTF8, SQLITE_STATIC);
    zExternal = sqlite3ValueText(pTmp, SQLITE_UTF16NATIVE);
    if( !zExternal ) return;
    db->xCollNeeded16(db->pCollNeededArg, db, (int)db->enc, zExternal);
  }
#endif
}

/*
** This routine is called if the collation factory fails to deliver a
** collation function in the best encoding but there may be other versions
** of this collation function (for other text encodings) available. Use one
** of these instead if they exist. Avoid a UTF-8 <-> UTF-16 conversion if
** possible.
*/
static int synthCollSeq(Parse *pParse, CollSeq *pColl){
  CollSeq *pColl2;
  char *z = pColl->zName;
  int n = strlen(z);
  sqlite3 *db = pParse->db;
  int i;
  static const u8 aEnc[] = { SQLITE_UTF16BE, SQLITE_UTF16LE, SQLITE_UTF8 };
  for(i=0; i<3; i++){
    pColl2 = sqlite3FindCollSeq(db, aEnc[i], z, n, 0);
    if( pColl2->xCmp!=0 ){
      memcpy(pColl, pColl2, sizeof(CollSeq));
      return SQLITE_OK;
    }
  }
  if( pParse->nErr==0 ){
    sqlite3ErrorMsg(pParse, "no such collation sequence: %.*s", n, z);
  }
  pParse->nErr++;
  return SQLITE_ERROR;
}

/*
** This routine is called on a collation sequence before it is used to
** check that it is defined. An undefined collation sequence exists when
** a database is loaded that contains references to collation sequences
** that have not been defined by sqlite3_create_collation() etc.
**
** If required, this routine calls the 'collation needed' callback to
** request a definition of the collating sequence. If this doesn't work, 
** an equivalent collating sequence that uses a text encoding different
** from the main database is substituted, if one is available.
*/
int sqlite3CheckCollSeq(Parse *pParse, CollSeq *pColl){
  if( pColl && !pColl->xCmp ){
    /* No collation sequence of this type for this encoding is registered.
    ** Call the collation factory to see if it can supply us with one.
    */
    callCollNeeded(pParse->db, pColl->zName, strlen(pColl->zName));
    if( !pColl->xCmp && synthCollSeq(pParse, pColl) ){
      return SQLITE_ERROR;
    }
  }
  return SQLITE_OK;
}

/*
** Call sqlite3CheckCollSeq() for all collating sequences in an index,
** in order to verify that all the necessary collating sequences are
** loaded.
*/
int sqlite3CheckIndexCollSeq(Parse *pParse, Index *pIdx){
  if( pIdx ){
    int i;
    for(i=0; i<pIdx->nColumn; i++){
      if( sqlite3CheckCollSeq(pParse, pIdx->keyInfo.aColl[i]) ){
        return SQLITE_ERROR;
      }
    }
  }
  return SQLITE_OK;
}

/*
** This function returns the collation sequence for database native text
** encoding identified by the string zName, length nName.
**
** If the requested collation sequence is not available, or not available
** in the database native encoding, the collation factory is invoked to
** request it. If the collation factory does not supply such a sequence,
** and the sequence is available in another text encoding, then that is
** returned instead.
**
** If no versions of the requested collations sequence are available, or
** another error occurs, NULL is returned and an error message written into
** pParse.
*/
CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName){
  u8 enc = pParse->db->enc;
  u8 initbusy = pParse->db->init.busy;
  CollSeq *pColl = sqlite3FindCollSeq(pParse->db, enc, zName, nName, initbusy);
  if( nName<0 ) nName = strlen(zName);
  if( !initbusy && (!pColl || !pColl->xCmp) ){
    /* No collation sequence of this type for this encoding is registered.
    ** Call the collation factory to see if it can supply us with one.
    */
    callCollNeeded(pParse->db, zName, nName);
    pColl = sqlite3FindCollSeq(pParse->db, enc, zName, nName, 0);
    if( pColl && !pColl->xCmp ){
      /* There may be a version of the collation sequence that requires
      ** translation between encodings. Search for it with synthCollSeq().
      */
      if( synthCollSeq(pParse, pColl) ){
        return 0;
      }
    }
  }

  /* If nothing has been found, write the error message into pParse */
  if( !initbusy && (!pColl || !pColl->xCmp) ){
    if( pParse->nErr==0 ){
      sqlite3ErrorMsg(pParse, "no such collation sequence: %.*s", nName, zName);
    }
    pColl = 0;
  }
  return pColl;
}


/*
** Generate code that will increment the schema cookie.
**
** The schema cookie is used to determine when the schema for the
** database changes.  After each schema change, the cookie value
** changes.  When a process first reads the schema it records the
** cookie.  Thereafter, whenever it goes to access the database,
** it checks the cookie to make sure the schema has not changed
** since it was last read.
**
** This plan is not completely bullet-proof.  It is possible for
** the schema to change multiple times and for the cookie to be
** set back to prior value.  But schema changes are infrequent
** and the probability of hitting the same cookie value is only
** 1 chance in 2^32.  So we're safe enough.
*/
void sqlite3ChangeCookie(sqlite3 *db, Vdbe *v, int iDb){
  sqlite3VdbeAddOp(v, OP_Integer, db->aDb[iDb].schema_cookie+1, 0);
  sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 0);
}

/*
** Measure the number of characters needed to output the given
** identifier.  The number returned includes any quotes used
** but does not include the null terminator.
**
** The estimate is conservative.  It might be larger that what is
** really needed.
*/
static int identLength(const char *z){
  int n;
  for(n=0; *z; n++, z++){
    if( *z=='"' ){ n++; }
  }
  return n + 2;
}

/*
** Write an identifier onto the end of the given string.  Add
** quote characters as needed.
*/
static void identPut(char *z, int *pIdx, char *zSignedIdent){
  unsigned char *zIdent = (unsigned char*)zSignedIdent;
  int i, j, needQuote;
  i = *pIdx;
  for(j=0; zIdent[j]; j++){
    if( !isalnum(zIdent[j]) && zIdent[j]!='_' ) break;
  }
  needQuote =  zIdent[j]!=0 || isdigit(zIdent[0])
                  || sqlite3KeywordCode(zIdent, j)!=TK_ID;
  if( needQuote ) z[i++] = '"';
  for(j=0; zIdent[j]; j++){
    z[i++] = zIdent[j];
    if( zIdent[j]=='"' ) z[i++] = '"';
  }
  if( needQuote ) z[i++] = '"';
  z[i] = 0;
  *pIdx = i;
}

/*
** Generate a CREATE TABLE statement appropriate for the given
** table.  Memory to hold the text of the statement is obtained
** from sqliteMalloc() and must be freed by the calling function.
*/
static char *createTableStmt(Table *p){
  int i, k, n;
  char *zStmt;
  char *zSep, *zSep2, *zEnd, *z;
  Column *pCol;
  n = 0;
  for(pCol = p->aCol, i=0; i<p->nCol; i++, pCol++){
    n += identLength(pCol->zName);
    z = pCol->zType;
    if( z ){
      n += (strlen(z) + 1);
    }
  }
  n += identLength(p->zName);
  if( n<50 ){
    zSep = "";
    zSep2 = ",";
    zEnd = ")";
  }else{
    zSep = "\n  ";
    zSep2 = ",\n  ";
    zEnd = "\n)";
  }
  n += 35 + 6*p->nCol;
  zStmt = sqliteMallocRaw( n );
  if( zStmt==0 ) return 0;
  strcpy(zStmt, p->iDb==1 ? "CREATE TEMP TABLE " : "CREATE TABLE ");
  k = strlen(zStmt);
  identPut(zStmt, &k, p->zName);
  zStmt[k++] = '(';
  for(pCol=p->aCol, i=0; i<p->nCol; i++, pCol++){
    strcpy(&zStmt[k], zSep);
    k += strlen(&zStmt[k]);
    zSep = zSep2;
    identPut(zStmt, &k, pCol->zName);
    if( (z = pCol->zType)!=0 ){
      zStmt[k++] = ' ';
      strcpy(&zStmt[k], z);
      k += strlen(z);
    }
  }
  strcpy(&zStmt[k], zEnd);
  return zStmt;
}

/*
** This routine is called to report the final ")" that terminates
** a CREATE TABLE statement.
**
** The table structure that other action routines have been building
** is added to the internal hash tables, assuming no errors have
** occurred.
**
** An entry for the table is made in the master table on disk, unless
** this is a temporary table or db->init.busy==1.  When db->init.busy==1
** it means we are reading the sqlite_master table because we just
** connected to the database or because the sqlite_master table has
** recently changes, so the entry for this table already exists in
** the sqlite_master table.  We do not want to create it again.
**
** If the pSelect argument is not NULL, it means that this routine
** was called to create a table generated from a 
** "CREATE TABLE ... AS SELECT ..." statement.  The column names of
** the new table will match the result set of the SELECT.
*/
void sqlite3EndTable(Parse *pParse, Token *pEnd, Select *pSelect){
  Table *p;
  sqlite3 *db = pParse->db;

  if( (pEnd==0 && pSelect==0) || pParse->nErr || sqlite3_malloc_failed ) return;
  p = pParse->pNewTable;
  if( p==0 ) return;

  assert( !db->init.busy || !pSelect );

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

  /* If not initializing, then create a record for the new table
  ** in the SQLITE_MASTER table of the database.  The record number
  ** for the new table entry should already be on the stack.
  **
  ** If this is a TEMPORARY table, write the entry into the auxiliary
  ** file instead of into the main database file.
  */
  if( !db->init.busy ){
    int n;
    Vdbe *v;
    char *zType;    /* "view" or "table" */
    char *zType2;   /* "VIEW" or "TABLE" */
    char *zStmt;    /* Text of the CREATE TABLE or CREATE VIEW statement */

    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;

    sqlite3VdbeAddOp(v, OP_Close, 0, 0);

    /* Create the rootpage for the new table and push it onto the stack.
    ** A view has no rootpage, so just push a zero onto the stack for
    ** views.  Initialize zType at the same time.
    */
    if( p->pSelect==0 ){
      /* A regular table */
      /* sqlite3VdbeAddOp(v, OP_CreateTable, p->iDb, 0); */
      zType = "table";
      zType2 = "TABLE";
#ifndef SQLITE_OMIT_VIEW
    }else{
      /* A view */
    /*  sqlite3VdbeAddOp(v, OP_Integer, 0, 0); */
      zType = "view";
      zType2 = "VIEW";
#endif
    }

    /* If this is a CREATE TABLE xx AS SELECT ..., execute the SELECT
    ** statement to populate the new table. The root-page number for the
    ** new table is on the top of the vdbe stack.
    **
    ** Once the SELECT has been coded by sqlite3Select(), it is in a
    ** suitable state to query for the column names and types to be used
    ** by the new table.
    */
    if( pSelect ){
      Table *pSelTab;
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      sqlite3VdbeAddOp(v, OP_Integer, p->iDb, 0);
      sqlite3VdbeAddOp(v, OP_OpenWrite, 1, 0);
      pParse->nTab = 2;
      sqlite3Select(pParse, pSelect, SRT_Table, 1, 0, 0, 0, 0);
      sqlite3VdbeAddOp(v, OP_Close, 1, 0);
      if( pParse->nErr==0 ){
        pSelTab = sqlite3ResultSetOfSelect(pParse, 0, pSelect);
        if( pSelTab==0 ) return;
        assert( p->aCol==0 );
        p->nCol = pSelTab->nCol;
        p->aCol = pSelTab->aCol;
        pSelTab->nCol = 0;
        pSelTab->aCol = 0;
        sqlite3DeleteTable(0, pSelTab);
      }
    }

    /* Compute the complete text of the CREATE statement */
    if( pSelect ){
      zStmt = createTableStmt(p);
    }else{
      n = Addr(pEnd->z) - Addr(pParse->sNameToken.z) + 1;
      zStmt = sqlite3MPrintf("CREATE %s %.*s", zType2, n, pParse->sNameToken.z);
    }

    /* A slot for the record has already been allocated in the 
    ** SQLITE_MASTER table.  We just need to update that slot with all
    ** the information we've collected.  The rowid for the preallocated
    ** slot is the 2nd item on the stack.  The top of the stack is the
    ** root page for the new table (or a 0 if this is a view).
    */
    sqlite3NestedParse(pParse,
      "UPDATE %Q.%s "
         "SET type='%s', name=%Q, tbl_name=%Q, rootpage=#0, sql=%Q "
       "WHERE rowid=#1",
      db->aDb[p->iDb].zName, SCHEMA_TABLE(p->iDb),
      zType,
      p->zName,
      p->zName,
      zStmt
    );
    sqliteFree(zStmt);
    sqlite3ChangeCookie(db, v, p->iDb);

#ifndef SQLITE_OMIT_AUTOINCREMENT
    /* Check to see if we need to create an sqlite_sequence table for
    ** keeping track of autoincrement keys.
    */
    if( p->autoInc ){
      Db *pDb = &db->aDb[p->iDb];
      if( pDb->pSeqTab==0 ){
        sqlite3NestedParse(pParse,
          "CREATE TABLE %Q.sqlite_sequence(name,seq)",
          pDb->zName
        );
      }
    }
#endif

    /* Reparse everything to update our internal data structures */
    sqlite3VdbeOp3(v, OP_ParseSchema, p->iDb, 0,
        sqlite3MPrintf("tbl_name='%q'",p->zName), P3_DYNAMIC);
  }


  /* Add the table to the in-memory representation of the database.
  */
  if( db->init.busy && pParse->nErr==0 ){
    Table *pOld;
    FKey *pFKey; 
    Db *pDb = &db->aDb[p->iDb];
    pOld = sqlite3HashInsert(&pDb->tblHash, p->zName, strlen(p->zName)+1, p);
    if( pOld ){
      assert( p==pOld );  /* Malloc must have failed inside HashInsert() */
      return;
    }
#ifndef SQLITE_OMIT_FOREIGN_KEY
    for(pFKey=p->pFKey; pFKey; pFKey=pFKey->pNextFrom){
      int nTo = strlen(pFKey->zTo) + 1;
      pFKey->pNextTo = sqlite3HashFind(&pDb->aFKey, pFKey->zTo, nTo);
      sqlite3HashInsert(&pDb->aFKey, pFKey->zTo, nTo, pFKey);
    }
#endif
    pParse->pNewTable = 0;
    db->nTable++;
    db->flags |= SQLITE_InternChanges;
  }
}

#ifndef SQLITE_OMIT_VIEW
/*
** The parser calls this routine in order to create a new VIEW
*/
void sqlite3CreateView(
  Parse *pParse,     /* The parsing context */
  Token *pBegin,     /* The CREATE token that begins the statement */
  Token *pName1,     /* The token that holds the name of the view */
  Token *pName2,     /* The token that holds the name of the view */
  Select *pSelect,   /* A SELECT statement that will become the new view */
  int isTemp         /* TRUE for a TEMPORARY view */
){
  Table *p;
  int n;
  const unsigned char *z;
  Token sEnd;
  DbFixer sFix;
  Token *pName;

  sqlite3StartTable(pParse, pBegin, pName1, pName2, isTemp, 1);
  p = pParse->pNewTable;
  if( p==0 || pParse->nErr ){
    sqlite3SelectDelete(pSelect);
    return;
  }
  sqlite3TwoPartName(pParse, pName1, pName2, &pName);
  if( sqlite3FixInit(&sFix, pParse, p->iDb, "view", pName)
    && sqlite3FixSelect(&sFix, pSelect)
  ){
    sqlite3SelectDelete(pSelect);
    return;
  }

  /* Make a copy of the entire SELECT statement that defines the view.
  ** This will force all the Expr.token.z values to be dynamically
  ** allocated rather than point to the input string - which means that
  ** they will persist after the current sqlite3_exec() call returns.
  */
  p->pSelect = sqlite3SelectDup(pSelect);
  sqlite3SelectDelete(pSelect);
  if( !pParse->db->init.busy ){
    sqlite3ViewGetColumnNames(pParse, p);
  }

  /* Locate the end of the CREATE VIEW statement.  Make sEnd point to
  ** the end.
  */
  sEnd = pParse->sLastToken;
  if( sEnd.z[0]!=0 && sEnd.z[0]!=';' ){
    sEnd.z += sEnd.n;
  }
  sEnd.n = 0;
  n = sEnd.z - pBegin->z;
  z = (const unsigned char*)pBegin->z;
  while( n>0 && (z[n-1]==';' || isspace(z[n-1])) ){ n--; }
  sEnd.z = &z[n-1];
  sEnd.n = 1;

  /* Use sqlite3EndTable() to add the view to the SQLITE_MASTER table */
  sqlite3EndTable(pParse, &sEnd, 0);
  return;
}
#endif /* SQLITE_OMIT_VIEW */

#ifndef SQLITE_OMIT_VIEW
/*
** The Table structure pTable is really a VIEW.  Fill in the names of
** the columns of the view in the pTable structure.  Return the number
** of errors.  If an error is seen leave an error message in pParse->zErrMsg.
*/
int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
  Table *pSelTab;   /* A fake table from which we get the result set */
  Select *pSel;     /* Copy of the SELECT that implements the view */
  int nErr = 0;     /* Number of errors encountered */
  int n;            /* Temporarily holds the number of cursors assigned */

  assert( pTable );

  /* A positive nCol means the columns names for this view are
  ** already known.
  */
  if( pTable->nCol>0 ) return 0;

  /* A negative nCol is a special marker meaning that we are currently
  ** trying to compute the column names.  If we enter this routine with
  ** a negative nCol, it means two or more views form a loop, like this:
  **
  **     CREATE VIEW one AS SELECT * FROM two;
  **     CREATE VIEW two AS SELECT * FROM one;
  **
  ** Actually, this error is caught previously and so the following test
  ** should always fail.  But we will leave it in place just to be safe.
  */
  if( pTable->nCol<0 ){
    sqlite3ErrorMsg(pParse, "view %s is circularly defined", pTable->zName);
    return 1;
  }

  /* If we get this far, it means we need to compute the table names.
  ** Note that the call to sqlite3ResultSetOfSelect() will expand any
  ** "*" elements in the results set of the view and will assign cursors
  ** to the elements of the FROM clause.  But we do not want these changes
  ** to be permanent.  So the computation is done on a copy of the SELECT
  ** statement that defines the view.
  */
  assert( pTable->pSelect );
  pSel = sqlite3SelectDup(pTable->pSelect);
  n = pParse->nTab;
  sqlite3SrcListAssignCursors(pParse, pSel->pSrc);
  pTable->nCol = -1;
  pSelTab = sqlite3ResultSetOfSelect(pParse, 0, pSel);
  pParse->nTab = n;
  if( pSelTab ){
    assert( pTable->aCol==0 );
    pTable->nCol = pSelTab->nCol;
    pTable->aCol = pSelTab->aCol;
    pSelTab->nCol = 0;
    pSelTab->aCol = 0;
    sqlite3DeleteTable(0, pSelTab);
    DbSetProperty(pParse->db, pTable->iDb, DB_UnresetViews);
  }else{
    pTable->nCol = 0;
    nErr++;
  }
  sqlite3SelectDelete(pSel);
  return nErr;  
}
#endif /* SQLITE_OMIT_VIEW */

#ifndef SQLITE_OMIT_VIEW
/*
** Clear the column names from every VIEW in database idx.
*/
static void sqliteViewResetAll(sqlite3 *db, int idx){
  HashElem *i;
  if( !DbHasProperty(db, idx, DB_UnresetViews) ) return;
  for(i=sqliteHashFirst(&db->aDb[idx].tblHash); i; i=sqliteHashNext(i)){
    Table *pTab = sqliteHashData(i);
    if( pTab->pSelect ){
      sqliteResetColumnNames(pTab);
    }
  }
  DbClearProperty(db, idx, DB_UnresetViews);
}
#else
# define sqliteViewResetAll(A,B)
#endif /* SQLITE_OMIT_VIEW */

/*
** This function is called by the VDBE to adjust the internal schema
** used by SQLite when the btree layer moves a table root page. The
** root-page of a table or index in database iDb has changed from iFrom
** to iTo.
*/
#ifndef SQLITE_OMIT_AUTOVACUUM
void sqlite3RootPageMoved(Db *pDb, int iFrom, int iTo){
  HashElem *pElem;
  
  for(pElem=sqliteHashFirst(&pDb->tblHash); pElem; pElem=sqliteHashNext(pElem)){
    Table *pTab = sqliteHashData(pElem);
    if( pTab->tnum==iFrom ){
      pTab->tnum = iTo;
      return;
    }
  }
  for(pElem=sqliteHashFirst(&pDb->idxHash); pElem; pElem=sqliteHashNext(pElem)){
    Index *pIdx = sqliteHashData(pElem);
    if( pIdx->tnum==iFrom ){
      pIdx->tnum = iTo;
      return;
    }
  }
  assert(0);
}
#endif

/*
** Write code to erase the table with root-page iTable from database iDb.
** Also write code to modify the sqlite_master table and internal schema
** if a root-page of another table is moved by the btree-layer whilst
** erasing iTable (this can happen with an auto-vacuum database).
*/ 
static void destroyRootPage(Parse *pParse, int iTable, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  sqlite3VdbeAddOp(v, OP_Destroy, iTable, iDb);
#ifndef SQLITE_OMIT_AUTOVACUUM
  /* OP_Destroy pushes an integer onto the stack. If this integer
  ** is non-zero, then it is the root page number of a table moved to
  ** location iTable. The following code modifies the sqlite_master table to
  ** reflect this.
  **
  ** The "#0" in the SQL is a special constant that means whatever value
  ** is on the top of the stack.  See sqlite3RegisterExpr().
  */
  sqlite3NestedParse(pParse, 
     "UPDATE %Q.%s SET rootpage=%d WHERE #0 AND rootpage=#0",
     pParse->db->aDb[iDb].zName, SCHEMA_TABLE(iDb), iTable);
#endif
}

/*
** Write VDBE code to erase table pTab and all associated indices on disk.
** Code to update the sqlite_master tables and internal schema definitions
** in case a root-page belonging to another table is moved by the btree layer
** is also added (this can happen with an auto-vacuum database).
*/
static void destroyTable(Parse *pParse, Table *pTab){
#ifdef SQLITE_OMIT_AUTOVACUUM
  Index *pIdx;
  destroyRootPage(pParse, pTab->tnum, pTab->iDb);
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    destroyRootPage(pParse, pIdx->tnum, pIdx->iDb);
  }
#else
  /* If the database may be auto-vacuum capable (if SQLITE_OMIT_AUTOVACUUM
  ** is not defined), then it is important to call OP_Destroy on the
  ** table and index root-pages in order, starting with the numerically 
  ** largest root-page number. This guarantees that none of the root-pages
  ** to be destroyed is relocated by an earlier OP_Destroy. i.e. if the
  ** following were coded:
  **
  ** OP_Destroy 4 0
  ** ...
  ** OP_Destroy 5 0
  **
  ** and root page 5 happened to be the largest root-page number in the
  ** database, then root page 5 would be moved to page 4 by the 
  ** "OP_Destroy 4 0" opcode. The subsequent "OP_Destroy 5 0" would hit
  ** a free-list page.
  */
  int iTab = pTab->tnum;
  int iDestroyed = 0;

  while( 1 ){
    Index *pIdx;
    int iLargest = 0;

    if( iDestroyed==0 || iTab<iDestroyed ){
      iLargest = iTab;
    }
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      int iIdx = pIdx->tnum;
      assert( pIdx->iDb==pTab->iDb );
      if( (iDestroyed==0 || (iIdx<iDestroyed)) && iIdx>iLargest ){
        iLargest = iIdx;
      }
    }
    if( iLargest==0 ) return;
    destroyRootPage(pParse, iLargest, pTab->iDb);
    iDestroyed = iLargest;
  }
#endif
}

/*
** This routine is called to do the work of a DROP TABLE statement.
** pName is the name of the table to be dropped.
*/
void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView){
  Table *pTab;
  Vdbe *v;
  sqlite3 *db = pParse->db;
  int iDb;

  if( pParse->nErr || sqlite3_malloc_failed ) goto exit_drop_table;
  assert( pName->nSrc==1 );
  pTab = sqlite3LocateTable(pParse, pName->a[0].zName, pName->a[0].zDatabase);

  if( pTab==0 ) goto exit_drop_table;
  iDb = pTab->iDb;
  assert( iDb>=0 && iDb<db->nDb );
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    int code;
    const char *zTab = SCHEMA_TABLE(pTab->iDb);
    const char *zDb = db->aDb[pTab->iDb].zName;
    if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb)){
      goto exit_drop_table;
    }
    if( isView ){
      if( iDb==1 ){
        code = SQLITE_DROP_TEMP_VIEW;
      }else{
        code = SQLITE_DROP_VIEW;
      }
    }else{
      if( iDb==1 ){
        code = SQLITE_DROP_TEMP_TABLE;
      }else{
        code = SQLITE_DROP_TABLE;
      }
    }
    if( sqlite3AuthCheck(pParse, code, pTab->zName, 0, zDb) ){
      goto exit_drop_table;
    }
    if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
      goto exit_drop_table;
    }
  }
#endif
  if( pTab->readOnly || pTab==db->aDb[iDb].pSeqTab ){
    sqlite3ErrorMsg(pParse, "table %s may not be dropped", pTab->zName);
    goto exit_drop_table;
  }

#ifndef SQLITE_OMIT_VIEW
  /* Ensure DROP TABLE is not used on a view, and DROP VIEW is not used
  ** on a table.
  */
  if( isView && pTab->pSelect==0 ){
    sqlite3ErrorMsg(pParse, "use DROP TABLE to delete table %s", pTab->zName);
    goto exit_drop_table;
  }
  if( !isView && pTab->pSelect ){
    sqlite3ErrorMsg(pParse, "use DROP VIEW to delete view %s", pTab->zName);
    goto exit_drop_table;
  }
#endif

  /* Generate code to remove the table from the master table
  ** on disk.
  */
  v = sqlite3GetVdbe(pParse);
  if( v ){
    Trigger *pTrigger;
    int iDb = pTab->iDb;
    Db *pDb = &db->aDb[iDb];
    sqlite3BeginWriteOperation(pParse, 0, iDb);

    /* Drop all triggers associated with the table being dropped. Code
    ** is generated to remove entries from sqlite_master and/or
    ** sqlite_temp_master if required.
    */
    pTrigger = pTab->pTrigger;
    while( pTrigger ){
      assert( pTrigger->iDb==iDb || pTrigger->iDb==1 );
      sqlite3DropTriggerPtr(pParse, pTrigger, 1);
      pTrigger = pTrigger->pNext;
    }

#ifndef SQLITE_OMIT_AUTOINCREMENT
    /* Remove any entries of the sqlite_sequence table associated with
    ** the table being dropped. This is done before the table is dropped
    ** at the btree level, in case the sqlite_sequence table needs to
    ** move as a result of the drop (can happen in auto-vacuum mode).
    */
    if( pTab->autoInc ){
      sqlite3NestedParse(pParse,
        "DELETE FROM %s.sqlite_sequence WHERE name=%Q",
        pDb->zName, pTab->zName
      );
    }
#endif

    /* Drop all SQLITE_MASTER table and index entries that refer to the
    ** table. The program name loops through the master table and deletes
    ** every row that refers to a table of the same name as the one being
    ** dropped. Triggers are handled seperately because a trigger can be
    ** created in the temp database that refers to a table in another
    ** database.
    */
    sqlite3NestedParse(pParse, 
        "DELETE FROM %Q.%s WHERE tbl_name=%Q and type!='trigger'",
        pDb->zName, SCHEMA_TABLE(iDb), pTab->zName);
    if( !isView ){
      destroyTable(pParse, pTab);
    }

    /* Remove the table entry from SQLite's internal schema and modify
    ** the schema cookie.
    */
    sqlite3VdbeOp3(v, OP_DropTable, iDb, 0, pTab->zName, 0);
    sqlite3ChangeCookie(db, v, iDb);
  }
  sqliteViewResetAll(db, iDb);

exit_drop_table:
  sqlite3SrcListDelete(pName);
}

/*
** This routine is called to create a new foreign key on the table
** currently under construction.  pFromCol determines which columns
** in the current table point to the foreign key.  If pFromCol==0 then
** connect the key to the last column inserted.  pTo is the name of
** the table referred to.  pToCol is a list of tables in the other
** pTo table that the foreign key points to.  flags contains all
** information about the conflict resolution algorithms specified
** in the ON DELETE, ON UPDATE and ON INSERT clauses.
**
** An FKey structure is created and added to the table currently
** under construction in the pParse->pNewTable field.  The new FKey
** is not linked into db->aFKey at this point - that does not happen
** until sqlite3EndTable().
**
** The foreign key is set for IMMEDIATE processing.  A subsequent call
** to sqlite3DeferForeignKey() might change this to DEFERRED.
*/
void sqlite3CreateForeignKey(
  Parse *pParse,       /* Parsing context */
  ExprList *pFromCol,  /* Columns in this table that point to other table */
  Token *pTo,          /* Name of the other table */
  ExprList *pToCol,    /* Columns in the other table */
  int flags            /* Conflict resolution algorithms. */
){
#ifndef SQLITE_OMIT_FOREIGN_KEY
  FKey *pFKey = 0;
  Table *p = pParse->pNewTable;
  int nByte;
  int i;
  int nCol;
  char *z;

  assert( pTo!=0 );
  if( p==0 || pParse->nErr ) goto fk_end;
  if( pFromCol==0 ){
    int iCol = p->nCol-1;
    if( iCol<0 ) goto fk_end;
    if( pToCol && pToCol->nExpr!=1 ){
      sqlite3ErrorMsg(pParse, "foreign key on %s"
         " should reference only one column of table %T",
         p->aCol[iCol].zName, pTo);
      goto fk_end;
    }
    nCol = 1;
  }else if( pToCol && pToCol->nExpr!=pFromCol->nExpr ){
    sqlite3ErrorMsg(pParse,
        "number of columns in foreign key does not match the number of "
        "columns in the referenced table");
    goto fk_end;
  }else{
    nCol = pFromCol->nExpr;
  }
  nByte = sizeof(*pFKey) + nCol*sizeof(pFKey->aCol[0]) + pTo->n + 1;
  if( pToCol ){
    for(i=0; i<pToCol->nExpr; i++){
      nByte += strlen(pToCol->a[i].zName) + 1;
    }
  }
  pFKey = sqliteMalloc( nByte );
  if( pFKey==0 ) goto fk_end;
  pFKey->pFrom = p;
  pFKey->pNextFrom = p->pFKey;
  z = (char*)&pFKey[1];
  pFKey->aCol = (struct sColMap*)z;
  z += sizeof(struct sColMap)*nCol;
  pFKey->zTo = z;
  memcpy(z, pTo->z, pTo->n);
  z[pTo->n] = 0;
  z += pTo->n+1;
  pFKey->pNextTo = 0;
  pFKey->nCol = nCol;
  if( pFromCol==0 ){
    pFKey->aCol[0].iFrom = p->nCol-1;
  }else{
    for(i=0; i<nCol; i++){
      int j;
      for(j=0; j<p->nCol; j++){
        if( sqlite3StrICmp(p->aCol[j].zName, pFromCol->a[i].zName)==0 ){
          pFKey->aCol[i].iFrom = j;
          break;
        }
      }
      if( j>=p->nCol ){
        sqlite3ErrorMsg(pParse, 
          "unknown column \"%s\" in foreign key definition", 
          pFromCol->a[i].zName);
        goto fk_end;
      }
    }
  }
  if( pToCol ){
    for(i=0; i<nCol; i++){
      int n = strlen(pToCol->a[i].zName);
      pFKey->aCol[i].zCol = z;
      memcpy(z, pToCol->a[i].zName, n);
      z[n] = 0;
      z += n+1;
    }
  }
  pFKey->isDeferred = 0;
  pFKey->deleteConf = flags & 0xff;
  pFKey->updateConf = (flags >> 8 ) & 0xff;
  pFKey->insertConf = (flags >> 16 ) & 0xff;

  /* Link the foreign key to the table as the last step.
  */
  p->pFKey = pFKey;
  pFKey = 0;

fk_end:
  sqliteFree(pFKey);
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
  sqlite3ExprListDelete(pFromCol);
  sqlite3ExprListDelete(pToCol);
}

/*
** This routine is called when an INITIALLY IMMEDIATE or INITIALLY DEFERRED
** clause is seen as part of a foreign key definition.  The isDeferred
** parameter is 1 for INITIALLY DEFERRED and 0 for INITIALLY IMMEDIATE.
** The behavior of the most recently created foreign key is adjusted
** accordingly.
*/
void sqlite3DeferForeignKey(Parse *pParse, int isDeferred){
#ifndef SQLITE_OMIT_FOREIGN_KEY
  Table *pTab;
  FKey *pFKey;
  if( (pTab = pParse->pNewTable)==0 || (pFKey = pTab->pFKey)==0 ) return;
  pFKey->isDeferred = isDeferred;
#endif
}

/*
** Generate code that will erase and refill index *pIdx.  This is
** used to initialize a newly created index or to recompute the
** content of an index in response to a REINDEX command.
**
** if memRootPage is not negative, it means that the index is newly
** created.  The memory cell specified by memRootPage contains the
** root page number of the index.  If memRootPage is negative, then
** the index already exists and must be cleared before being refilled and
** the root page number of the index is taken from pIndex->tnum.
*/
static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
  Table *pTab = pIndex->pTable;  /* The table that is indexed */
  int iTab = pParse->nTab;       /* Btree cursor used for pTab */
  int iIdx = pParse->nTab+1;     /* Btree cursor used for pIndex */
  int addr1;                     /* Address of top of loop */
  int tnum;                      /* Root page of index */
  Vdbe *v;                       /* Generate code into this virtual machine */
  int isUnique;                  /* True for a unique index */

#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
      pParse->db->aDb[pIndex->iDb].zName ) ){
    return;
  }
#endif

  /* Ensure all the required collation sequences are available. This
  ** routine will invoke the collation-needed callback if necessary (and
  ** if one has been registered).
  */
  if( sqlite3CheckIndexCollSeq(pParse, pIndex) ){
    return;
  }

  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  if( memRootPage>=0 ){
    sqlite3VdbeAddOp(v, OP_MemLoad, memRootPage, 0);
    tnum = 0;
  }else{
    tnum = pIndex->tnum;
    sqlite3VdbeAddOp(v, OP_Clear, tnum, pIndex->iDb);
  }
  sqlite3VdbeAddOp(v, OP_Integer, pIndex->iDb, 0);
  sqlite3VdbeOp3(v, OP_OpenWrite, iIdx, tnum,
                    (char*)&pIndex->keyInfo, P3_KEYINFO);
  sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0);
  sqlite3VdbeAddOp(v, OP_OpenRead, iTab, pTab->tnum);
  sqlite3VdbeAddOp(v, OP_SetNumColumns, iTab, pTab->nCol);
  addr1 = sqlite3VdbeAddOp(v, OP_Rewind, iTab, 0);
  sqlite3GenerateIndexKey(v, pIndex, iTab);
  isUnique = pIndex->onError!=OE_None;
  sqlite3VdbeAddOp(v, OP_IdxPut, iIdx, isUnique);
  if( isUnique ){
    sqlite3VdbeChangeP3(v, -1, "indexed columns are not unique", P3_STATIC);
  }
  sqlite3VdbeAddOp(v, OP_Next, iTab, addr1+1);
  sqlite3VdbeChangeP2(v, addr1, sqlite3VdbeCurrentAddr(v));
  sqlite3VdbeAddOp(v, OP_Close, iTab, 0);
  sqlite3VdbeAddOp(v, OP_Close, iIdx, 0);
}

/*
** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
** and pTblList is the name of the table that is to be indexed.  Both will 
** be NULL for a primary key or an index that is created to satisfy a
** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
** as the table to be indexed.  pParse->pNewTable is a table that is
** currently being constructed by a CREATE TABLE statement.
**
** pList is a list of columns to be indexed.  pList will be NULL if this
** is a primary key or unique-constraint on the most recent column added
** to the table currently under construction.  
*/
void sqlite3CreateIndex(
  Parse *pParse,     /* All information about this parse */
  Token *pName1,     /* First part of index name. May be NULL */
  Token *pName2,     /* Second part of index name. May be NULL */
  SrcList *pTblName, /* Table to index. Use pParse->pNewTable if 0 */
  ExprList *pList,   /* A list of columns to be indexed */
  int onError,       /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  Token *pStart,     /* The CREATE token that begins a CREATE TABLE statement */
  Token *pEnd        /* The ")" that closes the CREATE INDEX statement */
){
  Table *pTab = 0;   /* Table to be indexed */
  Index *pIndex = 0; /* The index to be created */
  char *zName = 0;
  int i, j;
  Token nullId;    /* Fake token for an empty ID list */
  DbFixer sFix;    /* For assigning database names to pTable */
  int isTemp;      /* True for a temporary index */
  sqlite3 *db = pParse->db;

  int iDb;          /* Index of the database that is being written */
  Token *pName = 0; /* Unqualified name of the index to create */

  if( pParse->nErr || sqlite3_malloc_failed ) goto exit_create_index;

  /*
  ** Find the table that is to be indexed.  Return early if not found.
  */
  if( pTblName!=0 ){

    /* Use the two-part index name to determine the database 
    ** to search for the table. 'Fix' the table name to this db
    ** before looking up the table.
    */
    assert( pName1 && pName2 );
    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
    if( iDb<0 ) goto exit_create_index;

    /* If the index name was unqualified, check if the the table
    ** is a temp table. If so, set the database to 1.
    */
    pTab = sqlite3SrcListLookup(pParse, pTblName);
    if( pName2 && pName2->n==0 && pTab && pTab->iDb==1 ){
      iDb = 1;
    }

    if( sqlite3FixInit(&sFix, pParse, iDb, "index", pName) &&
        sqlite3FixSrcList(&sFix, pTblName)
    ){
      goto exit_create_index;
    }
    pTab = sqlite3LocateTable(pParse, pTblName->a[0].zName, 
        pTblName->a[0].zDatabase);
    if( !pTab ) goto exit_create_index;
    assert( iDb==pTab->iDb );
  }else{
    assert( pName==0 );
    pTab =  pParse->pNewTable;
    iDb = pTab->iDb;
  }

  if( pTab==0 || pParse->nErr ) goto exit_create_index;
  if( pTab->readOnly ){
    sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
    goto exit_create_index;
  }
#ifndef SQLITE_OMIT_VIEW
  if( pTab->pSelect ){
    sqlite3ErrorMsg(pParse, "views may not be indexed");
    goto exit_create_index;
  }
#endif
  isTemp = pTab->iDb==1;

  /*
  ** Find the name of the index.  Make sure there is not already another
  ** index or table with the same name.  
  **
  ** Exception:  If we are reading the names of permanent indices from the
  ** sqlite_master table (because some other process changed the schema) and
  ** one of the index names collides with the name of a temporary table or
  ** index, then we will continue to process this index.
  **
  ** If pName==0 it means that we are
  ** dealing with a primary key or UNIQUE constraint.  We have to invent our
  ** own name.
  */
  if( pName ){
    zName = sqlite3NameFromToken(pName);
    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) goto exit_create_index;
    if( zName==0 ) goto exit_create_index;
    if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
      goto exit_create_index;
    }
    if( !db->init.busy ){
      Index *pISameName;    /* Another index with the same name */
      Table *pTSameName;    /* A table with same name as the index */
      if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) goto exit_create_index;
      if( (pISameName = sqlite3FindIndex(db, zName, db->aDb[iDb].zName))!=0 ){
        sqlite3ErrorMsg(pParse, "index %s already exists", zName);
        goto exit_create_index;
      }
      if( (pTSameName = sqlite3FindTable(db, zName, 0))!=0 ){
        sqlite3ErrorMsg(pParse, "there is already a table named %s", zName);
        goto exit_create_index;
      }
    }
  }else{
    char zBuf[30];
    int n;
    Index *pLoop;
    for(pLoop=pTab->pIndex, n=1; pLoop; pLoop=pLoop->pNext, n++){}
    sprintf(zBuf,"_%d",n);
    zName = 0;
    sqlite3SetString(&zName, "sqlite_autoindex_", pTab->zName, zBuf, (char*)0);
    if( zName==0 ) goto exit_create_index;
  }

  /* Check for authorization to create an index.
  */
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    const char *zDb = db->aDb[pTab->iDb].zName;
    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
      goto exit_create_index;
    }
    i = SQLITE_CREATE_INDEX;
    if( isTemp ) i = SQLITE_CREATE_TEMP_INDEX;
    if( sqlite3AuthCheck(pParse, i, zName, pTab->zName, zDb) ){
      goto exit_create_index;
    }
  }
#endif

  /* If pList==0, it means this routine was called to make a primary
  ** key out of the last column added to the table under construction.
  ** So create a fake list to simulate this.
  */
  if( pList==0 ){
    nullId.z = pTab->aCol[pTab->nCol-1].zName;
    nullId.n = strlen(nullId.z);
    pList = sqlite3ExprListAppend(0, 0, &nullId);
    if( pList==0 ) goto exit_create_index;
  }

  /* 
  ** Allocate the index structure. 
  */
  pIndex = sqliteMalloc( sizeof(Index) + strlen(zName) + 1 +
                        (sizeof(int) + sizeof(CollSeq*))*pList->nExpr );
  if( pIndex==0 ) goto exit_create_index;
  pIndex->aiColumn = (int*)&pIndex->keyInfo.aColl[pList->nExpr];
  pIndex->zName = (char*)&pIndex->aiColumn[pList->nExpr];
  strcpy(pIndex->zName, zName);
  pIndex->pTable = pTab;
  pIndex->nColumn = pList->nExpr;
  pIndex->onError = onError;
  pIndex->autoIndex = pName==0;
  pIndex->iDb = iDb;

  /* Scan the names of the columns of the table to be indexed and
  ** load the column indices into the Index structure.  Report an error
  ** if any column is not found.
  */
  for(i=0; i<pList->nExpr; i++){
    for(j=0; j<pTab->nCol; j++){
      if( sqlite3StrICmp(pList->a[i].zName, pTab->aCol[j].zName)==0 ) break;
    }
    if( j>=pTab->nCol ){
      sqlite3ErrorMsg(pParse, "table %s has no column named %s",
        pTab->zName, pList->a[i].zName);
      goto exit_create_index;
    }
    pIndex->aiColumn[i] = j;
    if( pList->a[i].pExpr ){
      assert( pList->a[i].pExpr->pColl );
      pIndex->keyInfo.aColl[i] = pList->a[i].pExpr->pColl;
    }else{
      pIndex->keyInfo.aColl[i] = pTab->aCol[j].pColl;
    }
    assert( pIndex->keyInfo.aColl[i] );
    if( !db->init.busy && 
        sqlite3CheckCollSeq(pParse, pIndex->keyInfo.aColl[i]) 
    ){
      goto exit_create_index;
    }
  }
  pIndex->keyInfo.nField = pList->nExpr;

  if( pTab==pParse->pNewTable ){
    /* This routine has been called to create an automatic index as a
    ** result of a PRIMARY KEY or UNIQUE clause on a column definition, or
    ** a PRIMARY KEY or UNIQUE clause following the column definitions.
    ** i.e. one of:
    **
    ** CREATE TABLE t(x PRIMARY KEY, y);
    ** CREATE TABLE t(x, y, UNIQUE(x, y));
    **
    ** Either way, check to see if the table already has such an index. If
    ** so, don't bother creating this one. This only applies to
    ** automatically created indices. Users can do as they wish with
    ** explicit indices.
    */
    Index *pIdx;
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      int k;
      assert( pIdx->onError!=OE_None );
      assert( pIdx->autoIndex );
      assert( pIndex->onError!=OE_None );

      if( pIdx->nColumn!=pIndex->nColumn ) continue;
      for(k=0; k<pIdx->nColumn; k++){
        if( pIdx->aiColumn[k]!=pIndex->aiColumn[k] ) break;
        if( pIdx->keyInfo.aColl[k]!=pIndex->keyInfo.aColl[k] ) break;
      }
      if( k==pIdx->nColumn ){
        if( pIdx->onError!=pIndex->onError ){
          /* This constraint creates the same index as a previous
          ** constraint specified somewhere in the CREATE TABLE statement.
          ** However the ON CONFLICT clauses are different. If both this 
          ** constraint and the previous equivalent constraint have explicit
          ** ON CONFLICT clauses this is an error. Otherwise, use the
          ** explicitly specified behaviour for the index.
          */
          if( !(pIdx->onError==OE_Default || pIndex->onError==OE_Default) ){
            sqlite3ErrorMsg(pParse, 
                "conflicting ON CONFLICT clauses specified", 0);
          }
          if( pIdx->onError==OE_Default ){
            pIdx->onError = pIndex->onError;
          }
        }
        goto exit_create_index;
      }
    }
  }

  /* Link the new Index structure to its table and to the other
  ** in-memory database structures. 
  */
  if( db->init.busy ){
    Index *p;
    p = sqlite3HashInsert(&db->aDb[pIndex->iDb].idxHash, 
                         pIndex->zName, strlen(pIndex->zName)+1, pIndex);
    if( p ){
      assert( p==pIndex );  /* Malloc must have failed */
      goto exit_create_index;
    }
    db->flags |= SQLITE_InternChanges;
    if( pTblName!=0 ){
      pIndex->tnum = db->init.newTnum;
    }
  }

  /* If the db->init.busy is 0 then create the index on disk.  This
  ** involves writing the index into the master table and filling in the
  ** index with the current table contents.
  **
  ** The db->init.busy is 0 when the user first enters a CREATE INDEX 
  ** command.  db->init.busy is 1 when a database is opened and 
  ** CREATE INDEX statements are read out of the master table.  In
  ** the latter case the index already exists on disk, which is why
  ** we don't want to recreate it.
  **
  ** If pTblName==0 it means this index is generated as a primary key
  ** or UNIQUE constraint of a CREATE TABLE statement.  Since the table
  ** has just been created, it contains no data and the index initialization
  ** step can be skipped.
  */
  else if( db->init.busy==0 ){
    Vdbe *v;
    char *zStmt;
    int iMem = pParse->nMem++;

    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto exit_create_index;

    /* Create the rootpage for the index
    */
    sqlite3BeginWriteOperation(pParse, 1, iDb);
    sqlite3VdbeAddOp(v, OP_CreateIndex, iDb, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, iMem, 0);

    /* Gather the complete text of the CREATE INDEX statement into
    ** the zStmt variable
    */
    if( pStart && pEnd ){
      /* A named index with an explicit CREATE INDEX statement */
      zStmt = sqlite3MPrintf("CREATE%s INDEX %.*s",
        onError==OE_None ? "" : " UNIQUE",
        Addr(pEnd->z) - Addr(pName->z) + 1,
        pName->z);
    }else{
      /* An automatic index created by a PRIMARY KEY or UNIQUE constraint */
      /* zStmt = sqlite3MPrintf(""); */
      zStmt = 0;
    }

    /* Add an entry in sqlite_master for this index
    */
    sqlite3NestedParse(pParse, 
        "INSERT INTO %Q.%s VALUES('index',%Q,%Q,#0,%Q);",
        db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
        pIndex->zName,
        pTab->zName,
        zStmt
    );
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
    sqliteFree(zStmt);

    /* Fill the index with data and reparse the schema. Code an OP_Expire
    ** to invalidate all pre-compiled statements.
    */
    if( pTblName ){
      sqlite3RefillIndex(pParse, pIndex, iMem);
      sqlite3ChangeCookie(db, v, iDb);
      sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0,
         sqlite3MPrintf("name='%q'", pIndex->zName), P3_DYNAMIC);
      sqlite3VdbeAddOp(v, OP_Expire, 0, 0);
    }
  }

  /* When adding an index to the list of indices for a table, make
  ** sure all indices labeled OE_Replace come after all those labeled
  ** OE_Ignore.  This is necessary for the correct operation of UPDATE
  ** and INSERT.
  */
  if( db->init.busy || pTblName==0 ){
    if( onError!=OE_Replace || pTab->pIndex==0
         || pTab->pIndex->onError==OE_Replace){
      pIndex->pNext = pTab->pIndex;
      pTab->pIndex = pIndex;
    }else{
      Index *pOther = pTab->pIndex;
      while( pOther->pNext && pOther->pNext->onError!=OE_Replace ){
        pOther = pOther->pNext;
      }
      pIndex->pNext = pOther->pNext;
      pOther->pNext = pIndex;
    }
    pIndex = 0;
  }

  /* Clean up before exiting */
exit_create_index:
  if( pIndex ){
    freeIndex(pIndex);
  }
  sqlite3ExprListDelete(pList);
  sqlite3SrcListDelete(pTblName);
  sqliteFree(zName);
  return;
}

/*
** This routine will drop an existing named index.  This routine
** implements the DROP INDEX statement.
*/
void sqlite3DropIndex(Parse *pParse, SrcList *pName){
  Index *pIndex;
  Vdbe *v;
  sqlite3 *db = pParse->db;

  if( pParse->nErr || sqlite3_malloc_failed ) return;
  assert( pName->nSrc==1 );
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) return;
  pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase);
  if( pIndex==0 ){
    sqlite3ErrorMsg(pParse, "no such index: %S", pName, 0);
    pParse->checkSchema = 1;
    goto exit_drop_index;
  }
  if( pIndex->autoIndex ){
    sqlite3ErrorMsg(pParse, "index associated with UNIQUE "
      "or PRIMARY KEY constraint cannot be dropped", 0);
    goto exit_drop_index;
  }
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    int code = SQLITE_DROP_INDEX;
    Table *pTab = pIndex->pTable;
    const char *zDb = db->aDb[pIndex->iDb].zName;
    const char *zTab = SCHEMA_TABLE(pIndex->iDb);
    if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
      goto exit_drop_index;
    }
    if( pIndex->iDb ) code = SQLITE_DROP_TEMP_INDEX;
    if( sqlite3AuthCheck(pParse, code, pIndex->zName, pTab->zName, zDb) ){
      goto exit_drop_index;
    }
  }
#endif

  /* Generate code to remove the index and from the master table */
  v = sqlite3GetVdbe(pParse);
  if( v ){
    int iDb = pIndex->iDb;
    sqlite3NestedParse(pParse,
       "DELETE FROM %Q.%s WHERE name=%Q",
       db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
       pIndex->zName
    );
    sqlite3ChangeCookie(db, v, iDb);
    destroyRootPage(pParse, pIndex->tnum, iDb);
    sqlite3VdbeOp3(v, OP_DropIndex, iDb, 0, pIndex->zName, 0);
  }

exit_drop_index:
  sqlite3SrcListDelete(pName);
}

/*
** Append a new element to the given IdList.  Create a new IdList if
** need be.
**
** A new IdList is returned, or NULL if malloc() fails.
*/
IdList *sqlite3IdListAppend(IdList *pList, Token *pToken){
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(IdList) );
    if( pList==0 ) return 0;
    pList->nAlloc = 0;
  }
  if( pList->nId>=pList->nAlloc ){
    struct IdList_item *a;
    pList->nAlloc = pList->nAlloc*2 + 5;
    a = sqliteRealloc(pList->a, pList->nAlloc*sizeof(pList->a[0]) );
    if( a==0 ){
      sqlite3IdListDelete(pList);
      return 0;
    }
    pList->a = a;
  }
  memset(&pList->a[pList->nId], 0, sizeof(pList->a[0]));
  pList->a[pList->nId].zName = sqlite3NameFromToken(pToken);
  pList->nId++;
  return pList;
}

/*
** Append a new table name to the given SrcList.  Create a new SrcList if
** need be.  A new entry is created in the SrcList even if pToken is NULL.
**
** A new SrcList is returned, or NULL if malloc() fails.
**
** If pDatabase is not null, it means that the table has an optional
** database name prefix.  Like this:  "database.table".  The pDatabase
** points to the table name and the pTable points to the database name.
** The SrcList.a[].zName field is filled with the table name which might
** come from pTable (if pDatabase is NULL) or from pDatabase.  
** SrcList.a[].zDatabase is filled with the database name from pTable,
** or with NULL if no database is specified.
**
** In other words, if call like this:
**
**         sqlite3SrcListAppend(A,B,0);
**
** Then B is a table name and the database name is unspecified.  If called
** like this:
**
**         sqlite3SrcListAppend(A,B,C);
**
** Then C is the table name and B is the database name.
*/
SrcList *sqlite3SrcListAppend(SrcList *pList, Token *pTable, Token *pDatabase){
  struct SrcList_item *pItem;
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(SrcList) );
    if( pList==0 ) return 0;
    pList->nAlloc = 1;
  }
  if( pList->nSrc>=pList->nAlloc ){
    SrcList *pNew;
    pList->nAlloc *= 2;
    pNew = sqliteRealloc(pList,
               sizeof(*pList) + (pList->nAlloc-1)*sizeof(pList->a[0]) );
    if( pNew==0 ){
      sqlite3SrcListDelete(pList);
      return 0;
    }
    pList = pNew;
  }
  pItem = &pList->a[pList->nSrc];
  memset(pItem, 0, sizeof(pList->a[0]));
  if( pDatabase && pDatabase->z==0 ){
    pDatabase = 0;
  }
  if( pDatabase && pTable ){
    Token *pTemp = pDatabase;
    pDatabase = pTable;
    pTable = pTemp;
  }
  pItem->zName = sqlite3NameFromToken(pTable);
  pItem->zDatabase = sqlite3NameFromToken(pDatabase);
  pItem->iCursor = -1;
  pList->nSrc++;
  return pList;
}

/*
** Assign cursors to all tables in a SrcList
*/
void sqlite3SrcListAssignCursors(Parse *pParse, SrcList *pList){
  int i;
  struct SrcList_item *pItem;
  for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
    if( pItem->iCursor>=0 ) break;
    pItem->iCursor = pParse->nTab++;
    if( pItem->pSelect ){
      sqlite3SrcListAssignCursors(pParse, pItem->pSelect->pSrc);
    }
  }
}

/*
** Add an alias to the last identifier on the given identifier list.
*/
void sqlite3SrcListAddAlias(SrcList *pList, Token *pToken){
  if( pList && pList->nSrc>0 ){
    pList->a[pList->nSrc-1].zAlias = sqlite3NameFromToken(pToken);
  }
}

/*
** Delete an IdList.
*/
void sqlite3IdListDelete(IdList *pList){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nId; i++){
    sqliteFree(pList->a[i].zName);
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

/*
** Return the index in pList of the identifier named zId.  Return -1
** if not found.
*/
int sqlite3IdListIndex(IdList *pList, const char *zName){
  int i;
  if( pList==0 ) return -1;
  for(i=0; i<pList->nId; i++){
    if( sqlite3StrICmp(pList->a[i].zName, zName)==0 ) return i;
  }
  return -1;
}

/*
** Delete an entire SrcList including all its substructure.
*/
void sqlite3SrcListDelete(SrcList *pList){
  int i;
  struct SrcList_item *pItem;
  if( pList==0 ) return;
  for(pItem=pList->a, i=0; i<pList->nSrc; i++, pItem++){
    sqliteFree(pItem->zDatabase);
    sqliteFree(pItem->zName);
    sqliteFree(pItem->zAlias);
    if( pItem->pTab && pItem->pTab->isTransient ){
      sqlite3DeleteTable(0, pItem->pTab);
    }
    sqlite3SelectDelete(pItem->pSelect);
    sqlite3ExprDelete(pItem->pOn);
    sqlite3IdListDelete(pItem->pUsing);
  }
  sqliteFree(pList);
}

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

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || sqlite3_malloc_failed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( !v ) return;
  if( type!=TK_DEFERRED ){
    for(i=0; i<db->nDb; i++){
      sqlite3VdbeAddOp(v, OP_Transaction, i, (type==TK_EXCLUSIVE)+1);
    }
  }
  sqlite3VdbeAddOp(v, OP_AutoCommit, 0, 0);
}

/*
** Commit a transaction
*/
void sqlite3CommitTransaction(Parse *pParse){
  sqlite3 *db;
  Vdbe *v;

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || sqlite3_malloc_failed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "COMMIT", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_AutoCommit, 1, 0);
  }
}

/*
** Rollback a transaction
*/
void sqlite3RollbackTransaction(Parse *pParse){
  sqlite3 *db;
  Vdbe *v;

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || sqlite3_malloc_failed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_AutoCommit, 1, 1);
  }
}

/*
** Make sure the TEMP database is open and available for use.  Return
** the number of errors.  Leave any error messages in the pParse structure.
*/
static int sqlite3OpenTempDatabase(Parse *pParse){
  sqlite3 *db = pParse->db;
  if( db->aDb[1].pBt==0 && !pParse->explain ){
    int rc = sqlite3BtreeFactory(db, 0, 0, MAX_PAGES, &db->aDb[1].pBt);
    if( rc!=SQLITE_OK ){
      sqlite3ErrorMsg(pParse, "unable to open a temporary database "
        "file for storing temporary tables");
      pParse->rc = rc;
      return 1;
    }
    if( db->flags & !db->autoCommit ){
      rc = sqlite3BtreeBeginTrans(db->aDb[1].pBt, 1);
      if( rc!=SQLITE_OK ){
        sqlite3ErrorMsg(pParse, "unable to get a write lock on "
          "the temporary database file");
        pParse->rc = rc;
        return 1;
      }
    }
  }
  return 0;
}

/*
** Generate VDBE code that will verify the schema cookie and start
** a read-transaction for all named database files.
**
** It is important that all schema cookies be verified and all
** read transactions be started before anything else happens in
** the VDBE program.  But this routine can be called after much other
** code has been generated.  So here is what we do:
**
** The first time this routine is called, we code an OP_Goto that
** will jump to a subroutine at the end of the program.  Then we
** record every database that needs its schema verified in the
** pParse->cookieMask field.  Later, after all other code has been
** generated, the subroutine that does the cookie verifications and
** starts the transactions will be coded and the OP_Goto P2 value
** will be made to point to that subroutine.  The generation of the
** cookie verification subroutine code happens in sqlite3FinishCoding().
**
** If iDb<0 then code the OP_Goto only - don't set flag to verify the
** schema on any databases.  This can be used to position the OP_Goto
** early in the code, before we know if any database tables will be used.
*/
void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
  sqlite3 *db;
  Vdbe *v;
  int mask;

  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;  /* This only happens if there was a prior error */
  db = pParse->db;
  if( pParse->cookieGoto==0 ){
    pParse->cookieGoto = sqlite3VdbeAddOp(v, OP_Goto, 0, 0)+1;
  }
  if( iDb>=0 ){
    assert( iDb<db->nDb );
    assert( db->aDb[iDb].pBt!=0 || iDb==1 );
    assert( iDb<32 );
    mask = 1<<iDb;
    if( (pParse->cookieMask & mask)==0 ){
      pParse->cookieMask |= mask;
      pParse->cookieValue[iDb] = db->aDb[iDb].schema_cookie;
      if( iDb==1 ){
        sqlite3OpenTempDatabase(pParse);
      }
    }
  }
}

/*
** Generate VDBE code that prepares for doing an operation that
** might change the database.
**
** This routine starts a new transaction if we are not already within
** a transaction.  If we are already within a transaction, then a checkpoint
** is set if the setStatement parameter is true.  A checkpoint should
** be set for operations that might fail (due to a constraint) part of
** the way through and which will need to undo some writes without having to
** rollback the whole transaction.  For operations where all constraints
** can be checked before any changes are made to the database, it is never
** necessary to undo a write and the checkpoint should not be set.
**
** Only database iDb and the temp database are made writable by this call.
** If iDb==0, then the main and temp databases are made writable.   If
** iDb==1 then only the temp database is made writable.  If iDb>1 then the
** specified auxiliary database and the temp database are made writable.
*/
void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  sqlite3CodeVerifySchema(pParse, iDb);
  pParse->writeMask |= 1<<iDb;
  if( setStatement && pParse->nested==0 ){
    sqlite3VdbeAddOp(v, OP_Statement, iDb, 0);
  }
  if( iDb!=1 && pParse->db->aDb[1].pBt!=0 ){
    sqlite3BeginWriteOperation(pParse, setStatement, 1);
  }
}

#ifndef SQLITE_OMIT_UTF16
/* 
** Return the transient sqlite3_value object used for encoding conversions
** during SQL compilation.
*/
sqlite3_value *sqlite3GetTransientValue(sqlite3 *db){
  if( !db->pValue ){
    db->pValue = sqlite3ValueNew();
  }
  return db->pValue;
}
#endif

/*
** Check to see if pIndex uses the collating sequence pColl.  Return
** true if it does and false if it does not.
*/
#ifndef SQLITE_OMIT_REINDEX
static int collationMatch(CollSeq *pColl, Index *pIndex){
  int n = pIndex->keyInfo.nField;
  CollSeq **pp = pIndex->keyInfo.aColl;
  while( n-- ){
    if( *pp==pColl ) return 1;
    pp++;
  }
  return 0;
}
#endif

/*
** Recompute all indices of pTab that use the collating sequence pColl.
** If pColl==0 then recompute all indices of pTab.
*/
#ifndef SQLITE_OMIT_REINDEX
void reindexTable(Parse *pParse, Table *pTab, CollSeq *pColl){
  Index *pIndex;              /* An index associated with pTab */

  for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
    if( pColl==0 || collationMatch(pColl,pIndex) ){
      sqlite3BeginWriteOperation(pParse, 0, pTab->iDb);
      sqlite3RefillIndex(pParse, pIndex, -1);
    }
  }
}
#endif

/*
** Recompute all indices of all tables in all databases where the
** indices use the collating sequence pColl.  If pColl==0 then recompute
** all indices everywhere.
*/
#ifndef SQLITE_OMIT_REINDEX
void reindexDatabases(Parse *pParse, CollSeq *pColl){
  Db *pDb;                    /* A single database */
  int iDb;                    /* The database index number */
  sqlite3 *db = pParse->db;   /* The database connection */
  HashElem *k;                /* For looping over tables in pDb */
  Table *pTab;                /* A table in the database */

  for(iDb=0, pDb=db->aDb; iDb<db->nDb; iDb++, pDb++){
    if( pDb==0 ) continue;
      for(k=sqliteHashFirst(&pDb->tblHash);  k; k=sqliteHashNext(k)){
      pTab = (Table*)sqliteHashData(k);
      reindexTable(pParse, pTab, pColl);
    }
  }
}
#endif

/*
** Generate code for the REINDEX command.
**
**        REINDEX                            -- 1
**        REINDEX  <collation>               -- 2
**        REINDEX  ?<database>.?<tablename>  -- 3
**        REINDEX  ?<database>.?<indexname>  -- 4
**
** Form 1 causes all indices in all attached databases to be rebuilt.
** Form 2 rebuilds all indices in all databases that use the named
** collating function.  Forms 3 and 4 rebuild the named index or all
** indices associated with the named table.
*/
#ifndef SQLITE_OMIT_REINDEX
void sqlite3Reindex(Parse *pParse, Token *pName1, Token *pName2){
  CollSeq *pColl;             /* Collating sequence to be reindexed, or NULL */
  char *z;                    /* Name of a table or index */
  const char *zDb;            /* Name of the database */
  Table *pTab;                /* A table in the database */
  Index *pIndex;              /* An index associated with pTab */
  int iDb;                    /* The database index number */
  sqlite3 *db = pParse->db;   /* The database connection */
  Token *pObjName;            /* Name of the table or index to be reindexed */

  /* Read the database schema. If an error occurs, leave an error message
  ** and code in pParse and return NULL. */
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    return;
  }

  if( pName1==0 || pName1->z==0 ){
    reindexDatabases(pParse, 0);
    return;
  }else if( pName2==0 || pName2->z==0 ){
    pColl = sqlite3FindCollSeq(db, db->enc, pName1->z, pName1->n, 0);
    if( pColl ){
      reindexDatabases(pParse, pColl);
      return;
    }
  }
  iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pObjName);
  if( iDb<0 ) return;
  z = sqlite3NameFromToken(pObjName);
  zDb = db->aDb[iDb].zName;
  pTab = sqlite3FindTable(db, z, zDb);
  if( pTab ){
    reindexTable(pParse, pTab, 0);
    sqliteFree(z);
    return;
  }
  pIndex = sqlite3FindIndex(db, z, zDb);
  sqliteFree(z);
  if( pIndex ){
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3RefillIndex(pParse, pIndex, -1);
    return;
  }
  sqlite3ErrorMsg(pParse, "unable to identify the object to be reindexed");
}
#endif

Added SQLite.Interop/src/config.h.



>
1
#define SQLITE_PTR_SZ 4

Added SQLite.Interop/src/date.c.

















































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































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/*
** 2003 October 31
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.1 2005/03/01 16:04:28 rmsimpson Exp $
**
** NOTES:
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system.
**
** 1970-01-01 00:00:00 is JD 2440587.5
** 2000-01-01 00:00:00 is JD 2451544.5
**
** This implemention requires years to be expressed as a 4-digit number
** which means that only dates between 0000-01-01 and 9999-12-31 can
** be represented, even though julian day numbers allow a much wider
** range of dates.
**
** The Gregorian calendar system is used for all dates and times,
** even those that predate the Gregorian calendar.  Historians usually
** use the Julian calendar for dates prior to 1582-10-15 and for some
** dates afterwards, depending on locale.  Beware of this difference.
**
** The conversion algorithms are implemented based on descriptions
** in the following text:
**
**      Jean Meeus
**      Astronomical Algorithms, 2nd Edition, 1998
**      ISBM 0-943396-61-1
**      Willmann-Bell, Inc
**      Richmond, Virginia (USA)
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.h>
#include <assert.h>
#include <time.h>

#ifndef SQLITE_OMIT_DATETIME_FUNCS

/*
** A structure for holding a single date and time.
*/
typedef struct DateTime DateTime;
struct DateTime {
  double rJD;      /* The julian day number */
  int Y, M, D;     /* Year, month, and day */
  int h, m;        /* Hour and minutes */
  int tz;          /* Timezone offset in minutes */
  double s;        /* Seconds */
  char validYMD;   /* True if Y,M,D are valid */
  char validHMS;   /* True if h,m,s are valid */
  char validJD;    /* True if rJD is valid */
  char validTZ;    /* True if tz is valid */
};


/*
** Convert zDate into one or more integers.  Additional arguments
** come in groups of 5 as follows:
**
**       N       number of digits in the integer
**       min     minimum allowed value of the integer
**       max     maximum allowed value of the integer
**       nextC   first character after the integer
**       pVal    where to write the integers value.
**
** Conversions continue until one with nextC==0 is encountered.
** The function returns the number of successful conversions.
*/
static int getDigits(const char *zDate, ...){
  va_list ap;
  int val;
  int N;
  int min;
  int max;
  int nextC;
  int *pVal;
  int cnt = 0;
  va_start(ap, zDate);
  do{
    N = va_arg(ap, int);
    min = va_arg(ap, int);
    max = va_arg(ap, int);
    nextC = va_arg(ap, int);
    pVal = va_arg(ap, int*);
    val = 0;
    while( N-- ){
      if( !isdigit(*(u8*)zDate) ){
        return cnt;
      }
      val = val*10 + *zDate - '0';
      zDate++;
    }
    if( val<min || val>max || (nextC!=0 && nextC!=*zDate) ){
      return cnt;
    }
    *pVal = val;
    zDate++;
    cnt++;
  }while( nextC );
  return cnt;
}

/*
** Read text from z[] and convert into a floating point number.  Return
** the number of digits converted.
*/
static int getValue(const char *z, double *pR){
  const char *zEnd;
  *pR = sqlite3AtoF(z, &zEnd);
  return zEnd - z;
}

/*
** Parse a timezone extension on the end of a date-time.
** The extension is of the form:
**
**        (+/-)HH:MM
**
** If the parse is successful, write the number of minutes
** of change in *pnMin and return 0.  If a parser error occurs,
** return 0.
**
** A missing specifier is not considered an error.
*/
static int parseTimezone(const char *zDate, DateTime *p){
  int sgn = 0;
  int nHr, nMn;
  while( isspace(*(u8*)zDate) ){ zDate++; }
  p->tz = 0;
  if( *zDate=='-' ){
    sgn = -1;
  }else if( *zDate=='+' ){
    sgn = +1;
  }else{
    return *zDate!=0;
  }
  zDate++;
  if( getDigits(zDate, 2, 0, 14, ':', &nHr, 2, 0, 59, 0, &nMn)!=2 ){
    return 1;
  }
  zDate += 5;
  p->tz = sgn*(nMn + nHr*60);
  while( isspace(*(u8*)zDate) ){ zDate++; }
  return *zDate!=0;
}

/*
** Parse times of the form HH:MM or HH:MM:SS or HH:MM:SS.FFFF.
** The HH, MM, and SS must each be exactly 2 digits.  The
** fractional seconds FFFF can be one or more digits.
**
** Return 1 if there is a parsing error and 0 on success.
*/
static int parseHhMmSs(const char *zDate, DateTime *p){
  int h, m, s;
  double ms = 0.0;
  if( getDigits(zDate, 2, 0, 24, ':', &h, 2, 0, 59, 0, &m)!=2 ){
    return 1;
  }
  zDate += 5;
  if( *zDate==':' ){
    zDate++;
    if( getDigits(zDate, 2, 0, 59, 0, &s)!=1 ){
      return 1;
    }
    zDate += 2;
    if( *zDate=='.' && isdigit((u8)zDate[1]) ){
      double rScale = 1.0;
      zDate++;
      while( isdigit(*(u8*)zDate) ){
        ms = ms*10.0 + *zDate - '0';
        rScale *= 10.0;
        zDate++;
      }
      ms /= rScale;
    }
  }else{
    s = 0;
  }
  p->validJD = 0;
  p->validHMS = 1;
  p->h = h;
  p->m = m;
  p->s = s + ms;
  if( parseTimezone(zDate, p) ) return 1;
  p->validTZ = p->tz!=0;
  return 0;
}

/*
** Convert from YYYY-MM-DD HH:MM:SS to julian day.  We always assume
** that the YYYY-MM-DD is according to the Gregorian calendar.
**
** Reference:  Meeus page 61
*/
static void computeJD(DateTime *p){
  int Y, M, D, A, B, X1, X2;

  if( p->validJD ) return;
  if( p->validYMD ){
    Y = p->Y;
    M = p->M;
    D = p->D;
  }else{
    Y = 2000;  /* If no YMD specified, assume 2000-Jan-01 */
    M = 1;
    D = 1;
  }
  if( M<=2 ){
    Y--;
    M += 12;
  }
  A = Y/100;
  B = 2 - A + (A/4);
  X1 = 365.25*(Y+4716);
  X2 = 30.6001*(M+1);
  p->rJD = X1 + X2 + D + B - 1524.5;
  p->validJD = 1;
  p->validYMD = 0;
  if( p->validHMS ){
    p->rJD += (p->h*3600.0 + p->m*60.0 + p->s)/86400.0;
    if( p->validTZ ){
      p->rJD += p->tz*60/86400.0;
      p->validHMS = 0;
      p->validTZ = 0;
    }
  }
}

/*
** Parse dates of the form
**
**     YYYY-MM-DD HH:MM:SS.FFF
**     YYYY-MM-DD HH:MM:SS
**     YYYY-MM-DD HH:MM
**     YYYY-MM-DD
**
** Write the result into the DateTime structure and return 0
** on success and 1 if the input string is not a well-formed
** date.
*/
static int parseYyyyMmDd(const char *zDate, DateTime *p){
  int Y, M, D, neg;

  if( zDate[0]=='-' ){
    zDate++;
    neg = 1;
  }else{
    neg = 0;
  }
  if( getDigits(zDate,4,0,9999,'-',&Y,2,1,12,'-',&M,2,1,31,0,&D)!=3 ){
    return 1;
  }
  zDate += 10;
  while( isspace(*(u8*)zDate) ){ zDate++; }
  if( parseHhMmSs(zDate, p)==0 ){
    /* We got the time */
  }else if( *zDate==0 ){
    p->validHMS = 0;
  }else{
    return 1;
  }
  p->validJD = 0;
  p->validYMD = 1;
  p->Y = neg ? -Y : Y;
  p->M = M;
  p->D = D;
  if( p->validTZ ){
    computeJD(p);
  }
  return 0;
}

/*
** Attempt to parse the given string into a Julian Day Number.  Return
** the number of errors.
**
** The following are acceptable forms for the input string:
**
**      YYYY-MM-DD HH:MM:SS.FFF  +/-HH:MM
**      DDDD.DD 
**      now
**
** In the first form, the +/-HH:MM is always optional.  The fractional
** seconds extension (the ".FFF") is optional.  The seconds portion
** (":SS.FFF") is option.  The year and date can be omitted as long
** as there is a time string.  The time string can be omitted as long
** as there is a year and date.
*/
static int parseDateOrTime(const char *zDate, DateTime *p){
  memset(p, 0, sizeof(*p));
  if( parseYyyyMmDd(zDate,p)==0 ){
    return 0;
  }else if( parseHhMmSs(zDate, p)==0 ){
    return 0;
  }else if( sqlite3StrICmp(zDate,"now")==0){
    double r;
    sqlite3OsCurrentTime(&r);
    p->rJD = r;
    p->validJD = 1;
    return 0;
  }else if( sqlite3IsNumber(zDate, 0, SQLITE_UTF8) ){
    p->rJD = sqlite3AtoF(zDate, 0);
    p->validJD = 1;
    return 0;
  }
  return 1;
}

/*
** Compute the Year, Month, and Day from the julian day number.
*/
static void computeYMD(DateTime *p){
  int Z, A, B, C, D, E, X1;
  if( p->validYMD ) return;
  if( !p->validJD ){
    p->Y = 2000;
    p->M = 1;
    p->D = 1;
  }else{
    Z = p->rJD + 0.5;
    A = (Z - 1867216.25)/36524.25;
    A = Z + 1 + A - (A/4);
    B = A + 1524;
    C = (B - 122.1)/365.25;
    D = 365.25*C;
    E = (B-D)/30.6001;
    X1 = 30.6001*E;
    p->D = B - D - X1;
    p->M = E<14 ? E-1 : E-13;
    p->Y = p->M>2 ? C - 4716 : C - 4715;
  }
  p->validYMD = 1;
}

/*
** Compute the Hour, Minute, and Seconds from the julian day number.
*/
static void computeHMS(DateTime *p){
  int Z, s;
  if( p->validHMS ) return;
  Z = p->rJD + 0.5;
  s = (p->rJD + 0.5 - Z)*86400000.0 + 0.5;
  p->s = 0.001*s;
  s = p->s;
  p->s -= s;
  p->h = s/3600;
  s -= p->h*3600;
  p->m = s/60;
  p->s += s - p->m*60;
  p->validHMS = 1;
}

/*
** Compute both YMD and HMS
*/
static void computeYMD_HMS(DateTime *p){
  computeYMD(p);
  computeHMS(p);
}

/*
** Clear the YMD and HMS and the TZ
*/
static void clearYMD_HMS_TZ(DateTime *p){
  p->validYMD = 0;
  p->validHMS = 0;
  p->validTZ = 0;
}

/*
** Compute the difference (in days) between localtime and UTC (a.k.a. GMT)
** for the time value p where p is in UTC.
*/
static double localtimeOffset(DateTime *p){
  DateTime x, y;
  time_t t;
  struct tm *pTm;
  x = *p;
  computeYMD_HMS(&x);
  if( x.Y<1971 || x.Y>=2038 ){
    x.Y = 2000;
    x.M = 1;
    x.D = 1;
    x.h = 0;
    x.m = 0;
    x.s = 0.0;
  } else {
    int s = x.s + 0.5;
    x.s = s;
  }
  x.tz = 0;
  x.validJD = 0;
  computeJD(&x);
  t = (x.rJD-2440587.5)*86400.0 + 0.5;
  sqlite3OsEnterMutex();
  pTm = localtime(&t);
  y.Y = pTm->tm_year + 1900;
  y.M = pTm->tm_mon + 1;
  y.D = pTm->tm_mday;
  y.h = pTm->tm_hour;
  y.m = pTm->tm_min;
  y.s = pTm->tm_sec;
  sqlite3OsLeaveMutex();
  y.validYMD = 1;
  y.validHMS = 1;
  y.validJD = 0;
  y.validTZ = 0;
  computeJD(&y);
  return y.rJD - x.rJD;
}

/*
** Process a modifier to a date-time stamp.  The modifiers are
** as follows:
**
**     NNN days
**     NNN hours
**     NNN minutes
**     NNN.NNNN seconds
**     NNN months
**     NNN years
**     start of month
**     start of year
**     start of week
**     start of day
**     weekday N
**     unixepoch
**     localtime
**     utc
**
** Return 0 on success and 1 if there is any kind of error.
*/
static int parseModifier(const char *zMod, DateTime *p){
  int rc = 1;
  int n;
  double r;
  char *z, zBuf[30];
  z = zBuf;
  for(n=0; n<sizeof(zBuf)-1 && zMod[n]; n++){
    z[n] = tolower(zMod[n]);
  }
  z[n] = 0;
  switch( z[0] ){
    case 'l': {
      /*    localtime
      **
      ** Assuming the current time value is UTC (a.k.a. GMT), shift it to
      ** show local time.
      */
      if( strcmp(z, "localtime")==0 ){
        computeJD(p);
        p->rJD += localtimeOffset(p);
        clearYMD_HMS_TZ(p);
        rc = 0;
      }
      break;
    }
    case 'u': {
      /*
      **    unixepoch
      **
      ** Treat the current value of p->rJD as the number of
      ** seconds since 1970.  Convert to a real julian day number.
      */
      if( strcmp(z, "unixepoch")==0 && p->validJD ){
        p->rJD = p->rJD/86400.0 + 2440587.5;
        clearYMD_HMS_TZ(p);
        rc = 0;
      }else if( strcmp(z, "utc")==0 ){
        double c1;
        computeJD(p);
        c1 = localtimeOffset(p);
        p->rJD -= c1;
        clearYMD_HMS_TZ(p);
        p->rJD += c1 - localtimeOffset(p);
        rc = 0;
      }
      break;
    }
    case 'w': {
      /*
      **    weekday N
      **
      ** Move the date to the same time on the next occurrence of
      ** weekday N where 0==Sunday, 1==Monday, and so forth.  If the
      ** date is already on the appropriate weekday, this is a no-op.
      */
      if( strncmp(z, "weekday ", 8)==0 && getValue(&z[8],&r)>0
                 && (n=r)==r && n>=0 && r<7 ){
        int Z;
        computeYMD_HMS(p);
        p->validTZ = 0;
        p->validJD = 0;
        computeJD(p);
        Z = p->rJD + 1.5;
        Z %= 7;
        if( Z>n ) Z -= 7;
        p->rJD += n - Z;
        clearYMD_HMS_TZ(p);
        rc = 0;
      }
      break;
    }
    case 's': {
      /*
      **    start of TTTTT
      **
      ** Move the date backwards to the beginning of the current day,
      ** or month or year.
      */
      if( strncmp(z, "start of ", 9)!=0 ) break;
      z += 9;
      computeYMD(p);
      p->validHMS = 1;
      p->h = p->m = 0;
      p->s = 0.0;
      p->validTZ = 0;
      p->validJD = 0;
      if( strcmp(z,"month")==0 ){
        p->D = 1;
        rc = 0;
      }else if( strcmp(z,"year")==0 ){
        computeYMD(p);
        p->M = 1;
        p->D = 1;
        rc = 0;
      }else if( strcmp(z,"day")==0 ){
        rc = 0;
      }
      break;
    }
    case '+':
    case '-':
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9': {
      n = getValue(z, &r);
      if( n<=0 ) break;
      if( z[n]==':' ){
        /* A modifier of the form (+|-)HH:MM:SS.FFF adds (or subtracts) the
        ** specified number of hours, minutes, seconds, and fractional seconds
        ** to the time.  The ".FFF" may be omitted.  The ":SS.FFF" may be
        ** omitted.
        */
        const char *z2 = z;
        DateTime tx;
        int day;
        if( !isdigit(*(u8*)z2) ) z2++;
        memset(&tx, 0, sizeof(tx));
        if( parseHhMmSs(z2, &tx) ) break;
        computeJD(&tx);
        tx.rJD -= 0.5;
        day = (int)tx.rJD;
        tx.rJD -= day;
        if( z[0]=='-' ) tx.rJD = -tx.rJD;
        computeJD(p);
        clearYMD_HMS_TZ(p);
       p->rJD += tx.rJD;
        rc = 0;
        break;
      }
      z += n;
      while( isspace(*(u8*)z) ) z++;
      n = strlen(z);
      if( n>10 || n<3 ) break;
      if( z[n-1]=='s' ){ z[n-1] = 0; n--; }
      computeJD(p);
      rc = 0;
      if( n==3 && strcmp(z,"day")==0 ){
        p->rJD += r;
      }else if( n==4 && strcmp(z,"hour")==0 ){
        p->rJD += r/24.0;
      }else if( n==6 && strcmp(z,"minute")==0 ){
        p->rJD += r/(24.0*60.0);
      }else if( n==6 && strcmp(z,"second")==0 ){
        p->rJD += r/(24.0*60.0*60.0);
      }else if( n==5 && strcmp(z,"month")==0 ){
        int x, y;
        computeYMD_HMS(p);
        p->M += r;
        x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12;
        p->Y += x;
        p->M -= x*12;
        p->validJD = 0;
        computeJD(p);
        y = r;
        if( y!=r ){
          p->rJD += (r - y)*30.0;
        }
      }else if( n==4 && strcmp(z,"year")==0 ){
        computeYMD_HMS(p);
        p->Y += r;
        p->validJD = 0;
        computeJD(p);
      }else{
        rc = 1;
      }
      clearYMD_HMS_TZ(p);
      break;
    }
    default: {
      break;
    }
  }
  return rc;
}

/*
** Process time function arguments.  argv[0] is a date-time stamp.
** argv[1] and following are modifiers.  Parse them all and write
** the resulting time into the DateTime structure p.  Return 0
** on success and 1 if there are any errors.
*/
static int isDate(int argc, sqlite3_value **argv, DateTime *p){
  int i;
  if( argc==0 ) return 1;
  if( SQLITE_NULL==sqlite3_value_type(argv[0]) || 
      parseDateOrTime(sqlite3_value_text(argv[0]), p) ) return 1;
  for(i=1; i<argc; i++){
    if( SQLITE_NULL==sqlite3_value_type(argv[i]) || 
        parseModifier(sqlite3_value_text(argv[i]), p) ) return 1;
  }
  return 0;
}


/*
** The following routines implement the various date and time functions
** of SQLite.
*/

/*
**    julianday( TIMESTRING, MOD, MOD, ...)
**
** Return the julian day number of the date specified in the arguments
*/
static void juliandayFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(argc, argv, &x)==0 ){
    computeJD(&x);
    sqlite3_result_double(context, x.rJD);
  }
}

/*
**    datetime( TIMESTRING, MOD, MOD, ...)
**
** Return YYYY-MM-DD HH:MM:SS
*/
static void datetimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(argc, argv, &x)==0 ){
    char zBuf[100];
    computeYMD_HMS(&x);
    sprintf(zBuf, "%04d-%02d-%02d %02d:%02d:%02d",x.Y, x.M, x.D, x.h, x.m,
           (int)(x.s));
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
  }
}

/*
**    time( TIMESTRING, MOD, MOD, ...)
**
** Return HH:MM:SS
*/
static void timeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(argc, argv, &x)==0 ){
    char zBuf[100];
    computeHMS(&x);
    sprintf(zBuf, "%02d:%02d:%02d", x.h, x.m, (int)x.s);
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
  }
}

/*
**    date( TIMESTRING, MOD, MOD, ...)
**
** Return YYYY-MM-DD
*/
static void dateFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(argc, argv, &x)==0 ){
    char zBuf[100];
    computeYMD(&x);
    sprintf(zBuf, "%04d-%02d-%02d", x.Y, x.M, x.D);
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
  }
}

/*
**    strftime( FORMAT, TIMESTRING, MOD, MOD, ...)
**
** Return a string described by FORMAT.  Conversions as follows:
**
**   %d  day of month
**   %f  ** fractional seconds  SS.SSS
**   %H  hour 00-24
**   %j  day of year 000-366
**   %J  ** Julian day number
**   %m  month 01-12
**   %M  minute 00-59
**   %s  seconds since 1970-01-01
**   %S  seconds 00-59
**   %w  day of week 0-6  sunday==0
**   %W  week of year 00-53
**   %Y  year 0000-9999
**   %%  %
*/
static void strftimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  int n, i, j;
  char *z;
  const char *zFmt = sqlite3_value_text(argv[0]);
  char zBuf[100];
  if( zFmt==0 || isDate(argc-1, argv+1, &x) ) return;
  for(i=0, n=1; zFmt[i]; i++, n++){
    if( zFmt[i]=='%' ){
      switch( zFmt[i+1] ){
        case 'd':
        case 'H':
        case 'm':
        case 'M':
        case 'S':
        case 'W':
          n++;
          /* fall thru */
        case 'w':
        case '%':
          break;
        case 'f':
          n += 8;
          break;
        case 'j':
          n += 3;
          break;
        case 'Y':
          n += 8;
          break;
        case 's':
        case 'J':
          n += 50;
          break;
        default:
          return;  /* ERROR.  return a NULL */
      }
      i++;
    }
  }
  if( n<sizeof(zBuf) ){
    z = zBuf;
  }else{
    z = sqliteMalloc( n );
    if( z==0 ) return;
  }
  computeJD(&x);
  computeYMD_HMS(&x);
  for(i=j=0; zFmt[i]; i++){
    if( zFmt[i]!='%' ){
      z[j++] = zFmt[i];
    }else{
      i++;
      switch( zFmt[i] ){
        case 'd':  sprintf(&z[j],"%02d",x.D); j+=2; break;
        case 'f': {
          int s = x.s;
          int ms = (x.s - s)*1000.0;
          sprintf(&z[j],"%02d.%03d",s,ms);
          j += strlen(&z[j]);
          break;
        }
        case 'H':  sprintf(&z[j],"%02d",x.h); j+=2; break;
        case 'W': /* Fall thru */
        case 'j': {
          int n;             /* Number of days since 1st day of year */
          DateTime y = x;
          y.validJD = 0;
          y.M = 1;
          y.D = 1;
          computeJD(&y);
          n = x.rJD - y.rJD;
          if( zFmt[i]=='W' ){
            int wd;   /* 0=Monday, 1=Tuesday, ... 6=Sunday */
            wd = ((int)(x.rJD+0.5)) % 7;
            sprintf(&z[j],"%02d",(n+7-wd)/7);
            j += 2;
          }else{
            sprintf(&z[j],"%03d",n+1);
            j += 3;
          }
          break;
        }
        case 'J':  sprintf(&z[j],"%.16g",x.rJD); j+=strlen(&z[j]); break;
        case 'm':  sprintf(&z[j],"%02d",x.M); j+=2; break;
        case 'M':  sprintf(&z[j],"%02d",x.m); j+=2; break;
        case 's': {
          sprintf(&z[j],"%d",(int)((x.rJD-2440587.5)*86400.0 + 0.5));
          j += strlen(&z[j]);
          break;
        }
        case 'S':  sprintf(&z[j],"%02d",(int)(x.s+0.5)); j+=2; break;
        case 'w':  z[j++] = (((int)(x.rJD+1.5)) % 7) + '0'; break;
        case 'Y':  sprintf(&z[j],"%04d",x.Y); j+=strlen(&z[j]); break;
        case '%':  z[j++] = '%'; break;
      }
    }
  }
  z[j] = 0;
  sqlite3_result_text(context, z, -1, SQLITE_TRANSIENT);
  if( z!=zBuf ){
    sqliteFree(z);
  }
}

/*
** current_time()
**
** This function returns the same value as time('now').
*/
static void ctimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew();
  if( pVal ){
    sqlite3ValueSetStr(pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    timeFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}

/*
** current_date()
**
** This function returns the same value as date('now').
*/
static void cdateFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew();
  if( pVal ){
    sqlite3ValueSetStr(pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    dateFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}

/*
** current_timestamp()
**
** This function returns the same value as datetime('now').
*/
static void ctimestampFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew();
  if( pVal ){
    sqlite3ValueSetStr(pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    datetimeFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}
#endif /* !defined(SQLITE_OMIT_DATETIME_FUNCS) */

#ifdef SQLITE_OMIT_DATETIME_FUNCS
/*
** If the library is compiled to omit the full-scale date and time
** handling (to get a smaller binary), the following minimal version
** of the functions current_time(), current_date() and current_timestamp()
** are included instead. This is to support column declarations that
** include "DEFAULT CURRENT_TIME" etc.
**
** This function uses the C-library functions time(), gmtime()
** and strftime(). The format string to pass to strftime() is supplied
** as the user-data for the function.
*/
static void currentTimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  time_t t;
  char *zFormat = (char *)sqlite3_user_data(context);
  char zBuf[20];

  time(&t);
#ifdef SQLITE_TEST
  {
    extern int sqlite3_current_time;  /* See os_XXX.c */
    if( sqlite3_current_time ){
      t = sqlite3_current_time;
    }
  }
#endif

  sqlite3OsEnterMutex();
  strftime(zBuf, 20, zFormat, gmtime(&t));
  sqlite3OsLeaveMutex();

  sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
}
#endif

/*
** This function registered all of the above C functions as SQL
** functions.  This should be the only routine in this file with
** external linkage.
*/
void sqlite3RegisterDateTimeFunctions(sqlite3 *db){
#ifndef SQLITE_OMIT_DATETIME_FUNCS
  static const struct {
     char *zName;
     int nArg;
     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } aFuncs[] = {
    { "julianday", -1, juliandayFunc   },
    { "date",      -1, dateFunc        },
    { "time",      -1, timeFunc        },
    { "datetime",  -1, datetimeFunc    },
    { "strftime",  -1, strftimeFunc    },
    { "current_time",       0, ctimeFunc      },
    { "current_timestamp",  0, ctimestampFunc },
    { "current_date",       0, cdateFunc      },
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
        SQLITE_UTF8, 0, aFuncs[i].xFunc, 0, 0);
  }
#else
  static const struct {
     char *zName;
     char *zFormat;
  } aFuncs[] = {
    { "current_time", "%H:%M:%S" },
    { "current_date", "%Y-%m-%d" },
    { "current_timestamp", "%Y-%m-%d %H:%M:%S" }
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3_create_function(db, aFuncs[i].zName, 0, SQLITE_UTF8, 
        aFuncs[i].zFormat, currentTimeFunc, 0, 0);
  }
#endif
}

Added SQLite.Interop/src/delete.c.























































































































































































































































































































































































































































































































































































































































































































































































































































































































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/*
** 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 file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.1 2005/03/01 16:04:29 rmsimpson Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.
*/
Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
  Table *pTab = 0;
  int i;
  struct SrcList_item *pItem;
  for(i=0, pItem=pSrc->a; i<pSrc->nSrc; i++, pItem++){
    pTab = sqlite3LocateTable(pParse, pItem->zName, pItem->zDatabase);
    pItem->pTab = pTab;
  }
  return pTab;
}

/*
** Check to make sure the given table is writable.  If it is not
** writable, generate an error message and return 1.  If it is
** writable return 0;
*/
int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){
  if( pTab->readOnly && (pParse->db->flags & SQLITE_WriteSchema)==0
        && pParse->nested==0 ){
    sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
    return 1;
  }
#ifndef SQLITE_OMIT_VIEW
  if( !viewOk && pTab->pSelect ){
    sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
    return 1;
  }
#endif
  return 0;
}

/*
** Generate code that will open a table for reading.
*/
void sqlite3OpenTableForReading(
  Vdbe *v,        /* Generate code into this VDBE */
  int iCur,       /* The cursor number of the table */
  Table *pTab     /* The table to be opened */
){
  sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0);
  sqlite3VdbeAddOp(v, OP_OpenRead, iCur, pTab->tnum);
  VdbeComment((v, "# %s", pTab->zName));
  sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol);
}


/*
** Generate code for a DELETE FROM statement.
**
**     DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
**                 \________/       \________________/
**                  pTabList              pWhere
*/
void sqlite3DeleteFrom(
  Parse *pParse,         /* The parser context */
  SrcList *pTabList,     /* The table from which we should delete things */
  Expr *pWhere           /* The WHERE clause.  May be null */
){
  Vdbe *v;               /* The virtual database engine */
  Table *pTab;           /* The table from which records will be deleted */
  const char *zDb;       /* Name of database holding pTab */
  int end, addr = 0;     /* A couple addresses of generated code */
  int i;                 /* Loop counter */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Index *pIdx;           /* For looping over indices of the table */
  int iCur;              /* VDBE Cursor number for pTab */
  sqlite3 *db;           /* Main database structure */
  AuthContext sContext;  /* Authorization context */
  int oldIdx = -1;       /* Cursor for the OLD table of AFTER triggers */
  NameContext sNC;       /* Name context to resolve expressions in */

#ifndef SQLITE_OMIT_TRIGGER
  int isView;                  /* True if attempting to delete from a view */
  int triggers_exist = 0;      /* True if any triggers exist */
#endif

  sContext.pParse = 0;
  if( pParse->nErr || sqlite3_malloc_failed ){
    pTabList = 0;
    goto delete_from_cleanup;
  }
  db = pParse->db;
  assert( pTabList->nSrc==1 );

  /* Locate the table which we want to delete.  This table has to be
  ** put in an SrcList structure because some of the subroutines we
  ** will be calling are designed to work with multiple tables and expect
  ** an SrcList* parameter instead of just a Table* parameter.
  */
  pTab = sqlite3SrcListLookup(pParse, pTabList);
  if( pTab==0 )  goto delete_from_cleanup;

  /* Figure out if we have any triggers and if the table being
  ** deleted from is a view
  */
#ifndef SQLITE_OMIT_TRIGGER
  triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0);
  isView = pTab->pSelect!=0;
#else
# define triggers_exist 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

  if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
    goto delete_from_cleanup;
  }
  assert( pTab->iDb<db->nDb );
  zDb = db->aDb[pTab->iDb].zName;
  if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
    goto delete_from_cleanup;
  }

  /* If pTab is really a view, make sure it has been initialized.
  */
  if( isView && sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto delete_from_cleanup;
  }

  /* Allocate a cursor used to store the old.* data for a trigger.
  */
  if( triggers_exist ){ 
    oldIdx = pParse->nTab++;
  }

  /* Resolve the column names in the WHERE clause.
  */
  assert( pTabList->nSrc==1 );
  iCur = pTabList->a[0].iCursor = pParse->nTab++;
  memset(&sNC, 0, sizeof(sNC));
  sNC.pParse = pParse;
  sNC.pSrcList = pTabList;
  if( sqlite3ExprResolveNames(&sNC, pWhere) ){
    goto delete_from_cleanup;
  }

  /* Start the view context
  */
  if( isView ){
    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
  }

  /* Begin generating code.
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ){
    goto delete_from_cleanup;
  }
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, triggers_exist, pTab->iDb);

  /* If we are trying to delete from a view, construct that view into
  ** a temporary table.
  */
  if( isView ){
    Select *pView = sqlite3SelectDup(pTab->pSelect);
    sqlite3Select(pParse, pView, SRT_TempTable, iCur, 0, 0, 0, 0);
    sqlite3SelectDelete(pView);
  }

  /* Initialize the counter of the number of rows deleted, if
  ** we are counting rows.
  */
  if( db->flags & SQLITE_CountRows ){
    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
  }

  /* Special case: A DELETE without a WHERE clause deletes everything.
  ** It is easier just to erase the whole table.  Note, however, that
  ** this means that the row change count will be incorrect.
  */
  if( pWhere==0 && !triggers_exist ){
    if( db->flags & SQLITE_CountRows ){
      /* If counting rows deleted, just count the total number of
      ** entries in the table. */
      int endOfLoop = sqlite3VdbeMakeLabel(v);
      int addr;
      if( !isView ){
        sqlite3OpenTableForReading(v, iCur, pTab);
      }
      sqlite3VdbeAddOp(v, OP_Rewind, iCur, sqlite3VdbeCurrentAddr(v)+2);
      addr = sqlite3VdbeAddOp(v, OP_AddImm, 1, 0);
      sqlite3VdbeAddOp(v, OP_Next, iCur, addr);
      sqlite3VdbeResolveLabel(v, endOfLoop);
      sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
    }
    if( !isView ){
      sqlite3VdbeAddOp(v, OP_Clear, pTab->tnum, pTab->iDb);
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        sqlite3VdbeAddOp(v, OP_Clear, pIdx->tnum, pIdx->iDb);
      }
    }
  }

  /* The usual case: There is a WHERE clause so we have to scan through
  ** the table and pick which records to delete.
  */
  else{
    /* Ensure all required collation sequences are available. */
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      if( sqlite3CheckIndexCollSeq(pParse, pIdx) ){
        goto delete_from_cleanup;
      }
    }

    /* Begin the database scan
    */
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0);
    if( pWInfo==0 ) goto delete_from_cleanup;

    /* Remember the rowid of every item to be deleted.
    */
    sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
    sqlite3VdbeAddOp(v, OP_ListWrite, 0, 0);
    if( db->flags & SQLITE_CountRows ){
      sqlite3VdbeAddOp(v, OP_AddImm, 1, 0);
    }

    /* End the database scan loop.
    */
    sqlite3WhereEnd(pWInfo);

    /* Open the pseudo-table used to store OLD if there are triggers.
    */
    if( triggers_exist ){
      sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
      sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
    }

    /* Delete every item whose key was written to the list during the
    ** database scan.  We have to delete items after the scan is complete
    ** because deleting an item can change the scan order.
    */
    sqlite3VdbeAddOp(v, OP_ListRewind, 0, 0);
    end = sqlite3VdbeMakeLabel(v);

    /* This is the beginning of the delete loop when there are
    ** row triggers.
    */
    if( triggers_exist ){
      addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, end);
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      if( !isView ){
        sqlite3OpenTableForReading(v, iCur, pTab);
      }
      sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
      sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
      sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
      sqlite3VdbeAddOp(v, OP_PutIntKey, oldIdx, 0);
      if( !isView ){
        sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
      }

      (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_BEFORE, pTab,
          -1, oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
	  addr);
    }

    if( !isView ){
      /* Open cursors for the table we are deleting from and all its
      ** indices.  If there are row triggers, this happens inside the
      ** OP_ListRead loop because the cursor have to all be closed
      ** before the trigger fires.  If there are no row triggers, the
      ** cursors are opened only once on the outside the loop.
      */
      sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);

      /* This is the beginning of the delete loop when there are no
      ** row triggers */
      if( !triggers_exist ){ 
        addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, end);
      }

      /* Delete the row */
      sqlite3GenerateRowDelete(db, v, pTab, iCur, pParse->nested==0);
    }

    /* If there are row triggers, close all cursors then invoke
    ** the AFTER triggers
    */
    if( triggers_exist ){
      if( !isView ){
        for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
          sqlite3VdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum);
        }
        sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
      }
      (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1,
          oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
	  addr);
    }

    /* End of the delete loop */
    sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
    sqlite3VdbeResolveLabel(v, end);
    sqlite3VdbeAddOp(v, OP_ListReset, 0, 0);

    /* Close the cursors after the loop if there are no row triggers */
    if( !triggers_exist ){
      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
        sqlite3VdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum);
      }
      sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
    }
  }

  /*
  ** Return the number of rows that were deleted. If this routine is 
  ** generating code because of a call to sqlite3NestedParse(), do not
  ** invoke the callback function.
  */
  if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
    sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, "rows deleted", P3_STATIC);
  }

delete_from_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3SrcListDelete(pTabList);
  sqlite3ExprDelete(pWhere);
  return;
}

/*
** This routine generates VDBE code that causes a single row of a
** single table to be deleted.
**
** The VDBE must be in a particular state when this routine is called.
** These are the requirements:
**
**   1.  A read/write cursor pointing to pTab, the table containing the row
**       to be deleted, must be opened as cursor number "base".
**
**   2.  Read/write cursors for all indices of pTab must be open as
**       cursor number base+i for the i-th index.
**
**   3.  The record number of the row to be deleted must be on the top
**       of the stack.
**
** This routine pops the top of the stack to remove the record number
** and then generates code to remove both the table record and all index
** entries that point to that record.
*/
void sqlite3GenerateRowDelete(
  sqlite3 *db,       /* The database containing the index */
  Vdbe *v,           /* Generate code into this VDBE */
  Table *pTab,       /* Table containing the row to be deleted */
  int iCur,          /* Cursor number for the table */
  int count          /* Increment the row change counter */
){
  int addr;
  addr = sqlite3VdbeAddOp(v, OP_NotExists, iCur, 0);
  sqlite3GenerateRowIndexDelete(db, v, pTab, iCur, 0);
  sqlite3VdbeAddOp(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
  sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));
}

/*
** This routine generates VDBE code that causes the deletion of all
** index entries associated with a single row of a single table.
**
** The VDBE must be in a particular state when this routine is called.
** These are the requirements:
**
**   1.  A read/write cursor pointing to pTab, the table containing the row
**       to be deleted, must be opened as cursor number "iCur".
**
**   2.  Read/write cursors for all indices of pTab must be open as
**       cursor number iCur+i for the i-th index.
**
**   3.  The "iCur" cursor must be pointing to the row that is to be
**       deleted.
*/
void sqlite3GenerateRowIndexDelete(
  sqlite3 *db,       /* The database containing the index */
  Vdbe *v,           /* Generate code into this VDBE */
  Table *pTab,       /* Table containing the row to be deleted */
  int iCur,          /* Cursor number for the table */
  char *aIdxUsed     /* Only delete if aIdxUsed!=0 && aIdxUsed[i]!=0 */
){
  int i;
  Index *pIdx;

  for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    if( aIdxUsed!=0 && aIdxUsed[i-1]==0 ) continue;
    sqlite3GenerateIndexKey(v, pIdx, iCur);
    sqlite3VdbeAddOp(v, OP_IdxDelete, iCur+i, 0);
  }
}

/*
** Generate code that will assemble an index key and put it on the top
** of the tack.  The key with be for index pIdx which is an index on pTab.
** iCur is the index of a cursor open on the pTab table and pointing to
** the entry that needs indexing.
*/
void sqlite3GenerateIndexKey(
  Vdbe *v,           /* Generate code into this VDBE */
  Index *pIdx,       /* The index for which to generate a key */
  int iCur           /* Cursor number for the pIdx->pTable table */
){
  int j;
  Table *pTab = pIdx->pTable;

  sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
  for(j=0; j<pIdx->nColumn; j++){
    int idx = pIdx->aiColumn[j];
    if( idx==pTab->iPKey ){
      sqlite3VdbeAddOp(v, OP_Dup, j, 0);
    }else{
      sqlite3VdbeAddOp(v, OP_Column, iCur, idx);
    }
  }
  sqlite3VdbeAddOp(v, OP_MakeRecord, pIdx->nColumn, (1<<24));
  sqlite3IndexAffinityStr(v, pIdx);
}

Added SQLite.Interop/src/expr.c.



























































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































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/*
** 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 file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.1 2005/03/01 16:04:29 rmsimpson Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,
** or a sub-select with a column as the return value, then the 
** affinity of that column is returned. Otherwise, 0x00 is returned,
** indicating no affinity for the expression.
**
** i.e. the WHERE clause expresssions in the following statements all
** have an affinity:
**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(Expr *pExpr){
  if( pExpr->op==TK_AS ){
    return sqlite3ExprAffinity(pExpr->pLeft);
  }
  if( pExpr->op==TK_SELECT ){
    return sqlite3ExprAffinity(pExpr->pSelect->pEList->a[0].pExpr);
  }
  return pExpr->affinity;
}

/*
** Return the default collation sequence for the expression pExpr. If
** there is no default collation type, return 0.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
  CollSeq *pColl = 0;
  if( pExpr ){
    pColl = pExpr->pColl;
    if( pExpr->op==TK_AS && !pColl ){
      return sqlite3ExprCollSeq(pParse, pExpr->pLeft);
    }
  }
  if( sqlite3CheckCollSeq(pParse, pColl) ){ 
    pColl = 0;
  }
  return pColl;
}

/*
** pExpr is an operand of a comparison operator.  aff2 is the
** type affinity of the other operand.  This routine returns the
** type affinity that should be used for the comparison operator.
*/
char sqlite3CompareAffinity(Expr *pExpr, char aff2){
  char aff1 = sqlite3ExprAffinity(pExpr);
  if( aff1 && aff2 ){
    /* Both sides of the comparison are columns. If one has numeric or
    ** integer affinity, use that. Otherwise use no affinity.
    */
    if( aff1==SQLITE_AFF_INTEGER || aff2==SQLITE_AFF_INTEGER ){
      return SQLITE_AFF_INTEGER;
    }else if( aff1==SQLITE_AFF_NUMERIC || aff2==SQLITE_AFF_NUMERIC ){
      return SQLITE_AFF_NUMERIC;
    }else{
      return SQLITE_AFF_NONE;
    }
  }else if( !aff1 && !aff2 ){
    /* Neither side of the comparison is a column.  Compare the
    ** results directly.
    */
    /* return SQLITE_AFF_NUMERIC;  // Ticket #805 */
    return SQLITE_AFF_NONE;
  }else{
    /* One side is a column, the other is not. Use the columns affinity. */
    return (aff1 + aff2);
  }
}

/*
** pExpr is a comparison operator.  Return the type affinity that should
** be applied to both operands prior to doing the comparison.
*/
static char comparisonAffinity(Expr *pExpr){
  char aff;
  assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
          pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
          pExpr->op==TK_NE );
  assert( pExpr->pLeft );
  aff = sqlite3ExprAffinity(pExpr->pLeft);
  if( pExpr->pRight ){
    aff = sqlite3CompareAffinity(pExpr->pRight, aff);
  }
  else if( pExpr->pSelect ){
    aff = sqlite3CompareAffinity(pExpr->pSelect->pEList->a[0].pExpr, aff);
  }
  else if( !aff ){
    aff = SQLITE_AFF_NUMERIC;
  }
  return aff;
}

/*
** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
** idx_affinity is the affinity of an indexed column. Return true
** if the index with affinity idx_affinity may be used to implement
** the comparison in pExpr.
*/
int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
  char aff = comparisonAffinity(pExpr);
  return 
    (aff==SQLITE_AFF_NONE) ||
    (aff==SQLITE_AFF_NUMERIC && idx_affinity==SQLITE_AFF_INTEGER) ||
    (aff==SQLITE_AFF_INTEGER && idx_affinity==SQLITE_AFF_NUMERIC) ||
    (aff==idx_affinity);
}

/*
** Return the P1 value that should be used for a binary comparison
** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
** If jumpIfNull is true, then set the low byte of the returned
** P1 value to tell the opcode to jump if either expression
** evaluates to NULL.
*/
static int binaryCompareP1(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
  char aff = sqlite3ExprAffinity(pExpr2);
  return (((int)sqlite3CompareAffinity(pExpr1, aff))<<8)+(jumpIfNull?1:0);
}

/*
** Return a pointer to the collation sequence that should be used by
** a binary comparison operator comparing pLeft and pRight.
**
** If the left hand expression has a collating sequence type, then it is
** used. Otherwise the collation sequence for the right hand expression
** is used, or the default (BINARY) if neither expression has a collating
** type.
*/
static CollSeq* binaryCompareCollSeq(Parse *pParse, Expr *pLeft, Expr *pRight){
  CollSeq *pColl = sqlite3ExprCollSeq(pParse, pLeft);
  if( !pColl ){
    pColl = sqlite3ExprCollSeq(pParse, pRight);
  }
  return pColl;
}

/*
** Generate code for a comparison operator.
*/
static int codeCompare(
  Parse *pParse,    /* The parsing (and code generating) context */
  Expr *pLeft,      /* The left operand */
  Expr *pRight,     /* The right operand */
  int opcode,       /* The comparison opcode */
  int dest,         /* Jump here if true.  */
  int jumpIfNull    /* If true, jump if either operand is NULL */
){
  int p1 = binaryCompareP1(pLeft, pRight, jumpIfNull);
  CollSeq *p3 = binaryCompareCollSeq(pParse, pLeft, pRight);
  return sqlite3VdbeOp3(pParse->pVdbe, opcode, p1, dest, (void*)p3, P3_COLLSEQ);
}

/*
** Construct a new expression node and return a pointer to it.  Memory
** for this node is obtained from sqliteMalloc().  The calling function
** is responsible for making sure the node eventually gets freed.
*/
Expr *sqlite3Expr(int op, Expr *pLeft, Expr *pRight, const Token *pToken){
  Expr *pNew;
  pNew = sqliteMalloc( sizeof(Expr) );
  if( pNew==0 ){
    /* When malloc fails, we leak memory from pLeft and pRight */
    return 0;
  }
  pNew->op = op;
  pNew->pLeft = pLeft;
  pNew->pRight = pRight;
  pNew->iAgg = -1;
  if( pToken ){
    assert( pToken->dyn==0 );
    pNew->span = pNew->token = *pToken;
  }else if( pLeft && pRight ){
    sqlite3ExprSpan(pNew, &pLeft->span, &pRight->span);
  }
  return pNew;
}

/*
** When doing a nested parse, you can include terms in an expression
** that look like this:   #0 #1 #2 ...  These terms refer to elements
** on the stack.  "#0" (or just "#") means the top of the stack.
** "#1" means the next down on the stack.  And so forth.  #-1 means
** memory location 0.  #-2 means memory location 1.  And so forth.
**
** This routine is called by the parser to deal with on of those terms.
** It immediately generates code to store the value in a memory location.
** The returns an expression that will code to extract the value from
** that memory location as needed.
*/
Expr *sqlite3RegisterExpr(Parse *pParse, Token *pToken){
  Vdbe *v = pParse->pVdbe;
  Expr *p;
  int depth;
  if( v==0 ) return 0;
  if( pParse->nested==0 ){
    sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", pToken);
    return 0;
  }
  p = sqlite3Expr(TK_REGISTER, 0, 0, pToken);
  if( p==0 ){
    return 0;  /* Malloc failed */
  }
  depth = atoi(&pToken->z[1]);
  if( depth>=0 ){
    p->iTable = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_Dup, depth, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, p->iTable, 1);
  }else{
    p->iTable = -1-depth;
  }
  return p;
}

/*
** Join two expressions using an AND operator.  If either expression is
** NULL, then just return the other expression.
*/
Expr *sqlite3ExprAnd(Expr *pLeft, Expr *pRight){
  if( pLeft==0 ){
    return pRight;
  }else if( pRight==0 ){
    return pLeft;
  }else{
    return sqlite3Expr(TK_AND, pLeft, pRight, 0);
  }
}

/*
** Set the Expr.span field of the given expression to span all
** text between the two given tokens.
*/
void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
  assert( pRight!=0 );
  assert( pLeft!=0 );
  if( !sqlite3_malloc_failed && pRight->z && pLeft->z ){
    assert( pLeft->dyn==0 || pLeft->z[pLeft->n]==0 );
    if( pLeft->dyn==0 && pRight->dyn==0 ){
      pExpr->span.z = pLeft->z;
      pExpr->span.n = pRight->n + Addr(pRight->z) - Addr(pLeft->z);
    }else{
      pExpr->span.z = 0;
    }
  }
}

/*
** Construct a new expression node for a function with multiple
** arguments.
*/
Expr *sqlite3ExprFunction(ExprList *pList, Token *pToken){
  Expr *pNew;
  pNew = sqliteMalloc( sizeof(Expr) );
  if( pNew==0 ){
    /* sqlite3ExprListDelete(pList); // Leak pList when malloc fails */
    return 0;
  }
  pNew->op = TK_FUNCTION;
  pNew->pList = pList;
  if( pToken ){
    assert( pToken->dyn==0 );
    pNew->token = *pToken;
  }else{
    pNew->token.z = 0;
  }
  pNew->span = pNew->token;
  return pNew;
}

/*
** Assign a variable number to an expression that encodes a wildcard
** in the original SQL statement.  
**
** Wildcards consisting of a single "?" are assigned the next sequential
** variable number.
**
** Wildcards of the form "?nnn" are assigned the number "nnn".  We make
** sure "nnn" is not too be to avoid a denial of service attack when
** the SQL statement comes from an external source.
**
** Wildcards of the form ":aaa" or "$aaa" are assigned the same number
** as the previous instance of the same wildcard.  Or if this is the first
** instance of the wildcard, the next sequenial variable number is
** assigned.
*/
void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
  Token *pToken;
  if( pExpr==0 ) return;
  pToken = &pExpr->token;
  assert( pToken->n>=1 );
  assert( pToken->z!=0 );
  assert( pToken->z[0]!=0 );
  if( pToken->n==1 ){
    /* Wildcard of the form "?".  Assign the next variable number */
    pExpr->iTable = ++pParse->nVar;
  }else if( pToken->z[0]=='?' ){
    /* Wildcard of the form "?nnn".  Convert "nnn" to an integer and
    ** use it as the variable number */
    int i;
    pExpr->iTable = i = atoi(&pToken->z[1]);
    if( i<1 || i>SQLITE_MAX_VARIABLE_NUMBER ){
      sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
          SQLITE_MAX_VARIABLE_NUMBER);
    }
    if( i>pParse->nVar ){
      pParse->nVar = i;
    }
  }else{
    /* Wildcards of the form ":aaa" or "$aaa".  Reuse the same variable
    ** number as the prior appearance of the same name, or if the name
    ** has never appeared before, reuse the same variable number
    */
    int i, n;
    n = pToken->n;
    for(i=0; i<pParse->nVarExpr; i++){
      Expr *pE;
      if( (pE = pParse->apVarExpr[i])!=0
          && pE->token.n==n
          && memcmp(pE->token.z, pToken->z, n)==0 ){
        pExpr->iTable = pE->iTable;
        break;
      }
    }
    if( i>=pParse->nVarExpr ){
      pExpr->iTable = ++pParse->nVar;
      if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
        pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
        pParse->apVarExpr = sqliteRealloc(pParse->apVarExpr,
                       pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0]) );
      }
      if( !sqlite3_malloc_failed ){
        assert( pParse->apVarExpr!=0 );
        pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
      }
    }
  } 
}

/*
** Recursively delete an expression tree.
*/
void sqlite3ExprDelete(Expr *p){
  if( p==0 ) return;
  if( p->span.dyn ) sqliteFree((char*)p->span.z);
  if( p->token.dyn ) sqliteFree((char*)p->token.z);
  sqlite3ExprDelete(p->pLeft);
  sqlite3ExprDelete(p->pRight);
  sqlite3ExprListDelete(p->pList);
  sqlite3SelectDelete(p->pSelect);
  sqliteFree(p);
}


/*
** The following group of routines make deep copies of expressions,
** expression lists, ID lists, and select statements.  The copies can
** be deleted (by being passed to their respective ...Delete() routines)
** without effecting the originals.
**
** The expression list, ID, and source lists return by sqlite3ExprListDup(),
** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded 
** by subsequent calls to sqlite*ListAppend() routines.
**
** Any tables that the SrcList might point to are not duplicated.
*/
Expr *sqlite3ExprDup(Expr *p){
  Expr *pNew;
  if( p==0 ) return 0;
  pNew = sqliteMallocRaw( sizeof(*p) );
  if( pNew==0 ) return 0;
  memcpy(pNew, p, sizeof(*pNew));
  if( p->token.z!=0 ){
    pNew->token.z = sqliteStrNDup(p->token.z, p->token.n);
    pNew->token.dyn = 1;
  }else{
    assert( pNew->token.z==0 );
  }
  pNew->span.z = 0;
  pNew->pLeft = sqlite3ExprDup(p->pLeft);
  pNew->pRight = sqlite3ExprDup(p->pRight);
  pNew->pList = sqlite3ExprListDup(p->pList);
  pNew->pSelect = sqlite3SelectDup(p->pSelect);
  return pNew;
}
void sqlite3TokenCopy(Token *pTo, Token *pFrom){
  if( pTo->dyn ) sqliteFree((char*)pTo->z);
  if( pFrom->z ){
    pTo->n = pFrom->n;
    pTo->z = sqliteStrNDup(pFrom->z, pFrom->n);
    pTo->dyn = 1;
  }else{
    pTo->z = 0;
  }
}
ExprList *sqlite3ExprListDup(ExprList *p){
  ExprList *pNew;
  struct ExprList_item *pItem, *pOldItem;
  int i;
  if( p==0 ) return 0;
  pNew = sqliteMalloc( sizeof(*pNew) );
  if( pNew==0 ) return 0;
  pNew->nExpr = pNew->nAlloc = p->nExpr;
  pNew->a = pItem = sqliteMalloc( p->nExpr*sizeof(p->a[0]) );
  if( pItem==0 ){
    sqliteFree(pNew);
    return 0;
  } 
  pOldItem = p->a;
  for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
    Expr *pNewExpr, *pOldExpr;
    pItem->pExpr = pNewExpr = sqlite3ExprDup(pOldExpr = pOldItem->pExpr);
    if( pOldExpr->span.z!=0 && pNewExpr ){
      /* Always make a copy of the span for top-level expressions in the
      ** expression list.  The logic in SELECT processing that determines
      ** the names of columns in the result set needs this information */
      sqlite3TokenCopy(&pNewExpr->span, &pOldExpr->span);
    }
    assert( pNewExpr==0 || pNewExpr->span.z!=0 
            || pOldExpr->span.z==0 || sqlite3_malloc_failed );
    pItem->zName = sqliteStrDup(pOldItem->zName);
    pItem->sortOrder = pOldItem->sortOrder;
    pItem->isAgg = pOldItem->isAgg;
    pItem->done = 0;
  }
  return pNew;
}

/*
** If cursors, triggers, views and subqueries are all omitted from
** the build, then none of the following routines, except for 
** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
** called with a NULL argument.
*/
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
 || !defined(SQLITE_OMIT_SUBQUERY)
SrcList *sqlite3SrcListDup(SrcList *p){
  SrcList *pNew;
  int i;
  int nByte;
  if( p==0 ) return 0;
  nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
  pNew = sqliteMallocRaw( nByte );
  if( pNew==0 ) return 0;
  pNew->nSrc = pNew->nAlloc = p->nSrc;
  for(i=0; i<p->nSrc; i++){
    struct SrcList_item *pNewItem = &pNew->a[i];
    struct SrcList_item *pOldItem = &p->a[i];
    pNewItem->zDatabase = sqliteStrDup(pOldItem->zDatabase);
    pNewItem->zName = sqliteStrDup(pOldItem->zName);
    pNewItem->zAlias = sqliteStrDup(pOldItem->zAlias);
    pNewItem->jointype = pOldItem->jointype;
    pNewItem->iCursor = pOldItem->iCursor;
    pNewItem->pTab = pOldItem->pTab;
    if( pNewItem->pTab ){
      pNewItem->pTab->isTransient = 0;
    }
    pNewItem->pSelect = sqlite3SelectDup(pOldItem->pSelect);
    pNewItem->pOn = sqlite3ExprDup(pOldItem->pOn);
    pNewItem->pUsing = sqlite3IdListDup(pOldItem->pUsing);
    pNewItem->colUsed = pOldItem->colUsed;
  }
  return pNew;
}
IdList *sqlite3IdListDup(IdList *p){
  IdList *pNew;
  int i;
  if( p==0 ) return 0;
  pNew = sqliteMallocRaw( sizeof(*pNew) );
  if( pNew==0 ) return 0;
  pNew->nId = pNew->nAlloc = p->nId;
  pNew->a = sqliteMallocRaw( p->nId*sizeof(p->a[0]) );
  if( pNew->a==0 ) return 0;
  for(i=0; i<p->nId; i++){
    struct IdList_item *pNewItem = &pNew->a[i];
    struct IdList_item *pOldItem = &p->a[i];
    pNewItem->zName = sqliteStrDup(pOldItem->zName);
    pNewItem->idx = pOldItem->idx;
  }
  return pNew;
}
Select *sqlite3SelectDup(Select *p){
  Select *pNew;
  if( p==0 ) return 0;
  pNew = sqliteMallocRaw( sizeof(*p) );
  if( pNew==0 ) return 0;
  pNew->isDistinct = p->isDistinct;
  pNew->pEList = sqlite3ExprListDup(p->pEList);
  pNew->pSrc = sqlite3SrcListDup(p->pSrc);
  pNew->pWhere = sqlite3ExprDup(p->pWhere);
  pNew->pGroupBy = sqlite3ExprListDup(p->pGroupBy);
  pNew->pHaving = sqlite3ExprDup(p->pHaving);
  pNew->pOrderBy = sqlite3ExprListDup(p->pOrderBy);
  pNew->op = p->op;
  pNew->pPrior = sqlite3SelectDup(p->pPrior);
  pNew->pLimit = sqlite3ExprDup(p->pLimit);
  pNew->pOffset = sqlite3ExprDup(p->pOffset);
  pNew->iLimit = -1;
  pNew->iOffset = -1;
  pNew->ppOpenTemp = 0;
  pNew->pFetch = 0;
  pNew->isResolved = p->isResolved;
  pNew->isAgg = p->isAgg;
  return pNew;
}
#else
Select *sqlite3SelectDup(Select *p){
  assert( p==0 );
  return 0;
}
#endif


/*
** Add a new element to the end of an expression list.  If pList is
** initially NULL, then create a new expression list.
*/
ExprList *sqlite3ExprListAppend(ExprList *pList, Expr *pExpr, Token *pName){
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(ExprList) );
    if( pList==0 ){
      /* sqlite3ExprDelete(pExpr); // Leak memory if malloc fails */
      return 0;
    }
    assert( pList->nAlloc==0 );
  }
  if( pList->nAlloc<=pList->nExpr ){
    pList->nAlloc = pList->nAlloc*2 + 4;
    pList->a = sqliteRealloc(pList->a, pList->nAlloc*sizeof(pList->a[0]));
    if( pList->a==0 ){
      /* sqlite3ExprDelete(pExpr); // Leak memory if malloc fails */
      pList->nExpr = pList->nAlloc = 0;
      return pList;
    }
  }
  assert( pList->a!=0 );
  if( pExpr || pName ){
    struct ExprList_item *pItem = &pList->a[pList->nExpr++];
    memset(pItem, 0, sizeof(*pItem));
    pItem->pExpr = pExpr;
    pItem->zName = sqlite3NameFromToken(pName);
  }
  return pList;
}

/*
** Delete an entire expression list.
*/
void sqlite3ExprListDelete(ExprList *pList){
  int i;
  struct ExprList_item *pItem;
  if( pList==0 ) return;
  assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
  assert( pList->nExpr<=pList->nAlloc );
  for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
    sqlite3ExprDelete(pItem->pExpr);
    sqliteFree(pItem->zName);
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

/*
** Walk an expression tree.  Call xFunc for each node visited.
**
** The return value from xFunc determines whether the tree walk continues.
** 0 means continue walking the tree.  1 means do not walk children
** of the current node but continue with siblings.  2 means abandon
** the tree walk completely.
**
** The return value from this routine is 1 to abandon the tree walk
** and 0 to continue.
*/
static int walkExprList(ExprList *, int (*)(void *, Expr*), void *);
static int walkExprTree(Expr *pExpr, int (*xFunc)(void*,Expr*), void *pArg){
  int rc;
  if( pExpr==0 ) return 0;
  rc = (*xFunc)(pArg, pExpr);
  if( rc==0 ){
    if( walkExprTree(pExpr->pLeft, xFunc, pArg) ) return 1;
    if( walkExprTree(pExpr->pRight, xFunc, pArg) ) return 1;
    if( walkExprList(pExpr->pList, xFunc, pArg) ) return 1;
  }
  return rc>1;
}

/*
** Call walkExprTree() for every expression in list p.
*/
static int walkExprList(ExprList *p, int (*xFunc)(void *, Expr*), void *pArg){
  int i;
  struct ExprList_item *pItem;
  if( !p ) return 0;
  for(i=p->nExpr, pItem=p->a; i>0; i--, pItem++){
    if( walkExprTree(pItem->pExpr, xFunc, pArg) ) return 1;
  }
  return 0;
}

/*
** Call walkExprTree() for every expression in Select p, not including
** expressions that are part of sub-selects in any FROM clause or the LIMIT
** or OFFSET expressions..
*/
static int walkSelectExpr(Select *p, int (*xFunc)(void *, Expr*), void *pArg){
  walkExprList(p->pEList, xFunc, pArg);
  walkExprTree(p->pWhere, xFunc, pArg);
  walkExprList(p->pGroupBy, xFunc, pArg);
  walkExprTree(p->pHaving, xFunc, pArg);
  walkExprList(p->pOrderBy, xFunc, pArg);
  return 0;
}


/*
** This routine is designed as an xFunc for walkExprTree().
**
** pArg is really a pointer to an integer.  If we can tell by looking
** at pExpr that the expression that contains pExpr is not a constant
** expression, then set *pArg to 0 and return 2 to abandon the tree walk.
** If pExpr does does not disqualify the expression from being a constant
** then do nothing.
**
** After walking the whole tree, if no nodes are found that disqualify
** the expression as constant, then we assume the whole expression
** is constant.  See sqlite3ExprIsConstant() for additional information.
*/
static int exprNodeIsConstant(void *pArg, Expr *pExpr){
  switch( pExpr->op ){
    case TK_ID:
    case TK_COLUMN:
    case TK_DOT:
    case TK_AGG_FUNCTION:
    case TK_FUNCTION:
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_SELECT:
    case TK_EXISTS:
#endif
      *((int*)pArg) = 0;
      return 2;
    default:
      return 0;
  }
}

/*
** Walk an expression tree.  Return 1 if the expression is constant
** and 0 if it involves variables.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstant(Expr *p){
  int isConst = 1;
  walkExprTree(p, exprNodeIsConstant, &isConst);
  return isConst;
}

/*
** If the expression p codes a constant integer that is small enough
** to fit in a 32-bit integer, return 1 and put the value of the integer
** in *pValue.  If the expression is not an integer or if it is too big
** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
*/
int sqlite3ExprIsInteger(Expr *p, int *pValue){
  switch( p->op ){
    case TK_INTEGER: {
      if( sqlite3GetInt32(p->token.z, pValue) ){
        return 1;
      }
      break;
    }
    case TK_UPLUS: {
      return sqlite3ExprIsInteger(p->pLeft, pValue);
    }
    case TK_UMINUS: {
      int v;
      if( sqlite3ExprIsInteger(p->pLeft, &v) ){
        *pValue = -v;
        return 1;
      }
      break;
    }
    default: break;
  }
  return 0;
}

/*
** Return TRUE if the given string is a row-id column name.
*/
int sqlite3IsRowid(const char *z){
  if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
  if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
  if( sqlite3StrICmp(z, "OID")==0 ) return 1;
  return 0;
}

/*
** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
** that name in the set of source tables in pSrcList and make the pExpr 
** expression node refer back to that source column.  The following changes
** are made to pExpr:
**
**    pExpr->iDb           Set the index in db->aDb[] of the database holding
**                         the table.
**    pExpr->iTable        Set to the cursor number for the table obtained
**                         from pSrcList.
**    pExpr->iColumn       Set to the column number within the table.
**    pExpr->op            Set to TK_COLUMN.
**    pExpr->pLeft         Any expression this points to is deleted
**    pExpr->pRight        Any expression this points to is deleted.
**
** The pDbToken is the name of the database (the "X").  This value may be
** NULL meaning that name is of the form Y.Z or Z.  Any available database
** can be used.  The pTableToken is the name of the table (the "Y").  This
** value can be NULL if pDbToken is also NULL.  If pTableToken is NULL it
** means that the form of the name is Z and that columns from any table
** can be used.
**
** If the name cannot be resolved unambiguously, leave an error message
** in pParse and return non-zero.  Return zero on success.
*/
static int lookupName(
  Parse *pParse,      /* The parsing context */
  Token *pDbToken,     /* Name of the database containing table, or NULL */
  Token *pTableToken,  /* Name of table containing column, or NULL */
  Token *pColumnToken, /* Name of the column. */
  NameContext *pNC,    /* The name context used to resolve the name */
  Expr *pExpr          /* Make this EXPR node point to the selected column */
){
  char *zDb = 0;       /* Name of the database.  The "X" in X.Y.Z */
  char *zTab = 0;      /* Name of the table.  The "Y" in X.Y.Z or Y.Z */
  char *zCol = 0;      /* Name of the column.  The "Z" */
  int i, j;            /* Loop counters */
  int cnt = 0;         /* Number of matching column names */
  int cntTab = 0;      /* Number of matching table names */
  sqlite3 *db = pParse->db;  /* The database */
  struct SrcList_item *pItem;       /* Use for looping over pSrcList items */
  struct SrcList_item *pMatch = 0;  /* The matching pSrcList item */
  NameContext *pTopNC = pNC;        /* First namecontext in the list */

  assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
  zDb = sqlite3NameFromToken(pDbToken);
  zTab = sqlite3NameFromToken(pTableToken);
  zCol = sqlite3NameFromToken(pColumnToken);
  if( sqlite3_malloc_failed ){
    return 1;  /* Leak memory (zDb and zTab) if malloc fails */
  }

  pExpr->iTable = -1;
  while( pNC && cnt==0 ){
    SrcList *pSrcList = pNC->pSrcList;
    ExprList *pEList = pNC->pEList;

    pNC->nRef++;
    /* assert( zTab==0 || pEList==0 ); */
    if( pSrcList ){
      for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
        Table *pTab = pItem->pTab;
        Column *pCol;
  
        if( pTab==0 ) continue;
        assert( pTab->nCol>0 );
        if( zTab ){
          if( pItem->zAlias ){
            char *zTabName = pItem->zAlias;
            if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
          }else{
            char *zTabName = pTab->zName;
            if( zTabName==0 || sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
            if( zDb!=0 && sqlite3StrICmp(db->aDb[pTab->iDb].zName, zDb)!=0 ){
              continue;
            }
          }
        }
        if( 0==(cntTab++) ){
          pExpr->iTable = pItem->iCursor;
          pExpr->iDb = pTab->iDb;
          pMatch = pItem;
        }
        for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
          if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
            cnt++;
            pExpr->iTable = pItem->iCursor;
            pMatch = pItem;
            pExpr->iDb = pTab->iDb;
            /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
            pExpr->iColumn = j==pTab->iPKey ? -1 : j;
            pExpr->affinity = pTab->aCol[j].affinity;
            pExpr->pColl = pTab->aCol[j].pColl;
            break;
          }
        }
      }
    }

#ifndef SQLITE_OMIT_TRIGGER
    /* If we have not already resolved the name, then maybe 
    ** it is a new.* or old.* trigger argument reference
    */
    if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){
      TriggerStack *pTriggerStack = pParse->trigStack;
      Table *pTab = 0;
      if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){
        pExpr->iTable = pTriggerStack->newIdx;
        assert( pTriggerStack->pTab );
        pTab = pTriggerStack->pTab;
      }else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab)==0 ){
        pExpr->iTable = pTriggerStack->oldIdx;
        assert( pTriggerStack->pTab );
        pTab = pTriggerStack->pTab;
      }

      if( pTab ){ 
        int j;
        Column *pCol = pTab->aCol;

        pExpr->iDb = pTab->iDb;
        cntTab++;
        for(j=0; j < pTab->nCol; j++, pCol++) {
          if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
            cnt++;
            pExpr->iColumn = j==pTab->iPKey ? -1 : j;
            pExpr->affinity = pTab->aCol[j].affinity;
            pExpr->pColl = pTab->aCol[j].pColl;
            break;
          }
        }
      }
    }
#endif /* !defined(SQLITE_OMIT_TRIGGER) */

    /*
    ** Perhaps the name is a reference to the ROWID
    */
    if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){
      cnt = 1;
      pExpr->iColumn = -1;
      pExpr->affinity = SQLITE_AFF_INTEGER;
    }

    /*
    ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
    ** might refer to an result-set alias.  This happens, for example, when
    ** we are resolving names in the WHERE clause of the following command:
    **
    **     SELECT a+b AS x FROM table WHERE x<10;
    **
    ** In cases like this, replace pExpr with a copy of the expression that
    ** forms the result set entry ("a+b" in the example) and return immediately.
    ** Note that the expression in the result set should have already been
    ** resolved by the time the WHERE clause is resolved.
    */
    if( cnt==0 && pEList!=0 && zTab==0 ){
      for(j=0; j<pEList->nExpr; j++){
        char *zAs = pEList->a[j].zName;
        if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
          assert( pExpr->pLeft==0 && pExpr->pRight==0 );
          pExpr->op = TK_AS;
          pExpr->iColumn = j;
          pExpr->pLeft = sqlite3ExprDup(pEList->a[j].pExpr);
          sqliteFree(zCol);
          assert( zTab==0 && zDb==0 );
          return 0;
        }
      } 
    }

    /* Advance to the next name context.  The loop will exit when either
    ** we have a match (cnt>0) or when we run out of name contexts.
    */
    if( cnt==0 ){
      pNC = pNC->pNext;
    }
  }

  /*
  ** If X and Y are NULL (in other words if only the column name Z is
  ** supplied) and the value of Z is enclosed in double-quotes, then
  ** Z is a string literal if it doesn't match any column names.  In that
  ** case, we need to return right away and not make any changes to
  ** pExpr.
  */
  if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){
    sqliteFree(zCol);
    return 0;
  }

  /*
  ** cnt==0 means there was not match.  cnt>1 means there were two or
  ** more matches.  Either way, we have an error.
  */
  if( cnt!=1 ){
    char *z = 0;
    char *zErr;
    zErr = cnt==0 ? "no such column: %s" : "ambiguous column name: %s";
    if( zDb ){
      sqlite3SetString(&z, zDb, ".", zTab, ".", zCol, 0);
    }else if( zTab ){
      sqlite3SetString(&z, zTab, ".", zCol, 0);
    }else{
      z = sqliteStrDup(zCol);
    }
    sqlite3ErrorMsg(pParse, zErr, z);
    sqliteFree(z);
    pTopNC->nErr++;
  }

  /* If a column from a table in pSrcList is referenced, then record
  ** this fact in the pSrcList.a[].colUsed bitmask.  Column 0 causes
  ** bit 0 to be set.  Column 1 sets bit 1.  And so forth.  If the
  ** column number is greater than the number of bits in the bitmask
  ** then set the high-order bit of the bitmask.
  */
  if( pExpr->iColumn>=0 && pMatch!=0 ){
    int n = pExpr->iColumn;
    if( n>=sizeof(Bitmask)*8 ){
      n = sizeof(Bitmask)*8-1;
    }
    assert( pMatch->iCursor==pExpr->iTable );
    pMatch->colUsed |= 1<<n;
  }

  /* Clean up and return
  */
  sqliteFree(zDb);
  sqliteFree(zTab);
  sqliteFree(zCol);
  sqlite3ExprDelete(pExpr->pLeft);
  pExpr->pLeft = 0;
  sqlite3ExprDelete(pExpr->pRight);
  pExpr->pRight = 0;
  pExpr->op = TK_COLUMN;
  if( cnt==1 ){
    assert( pNC!=0 );
    sqlite3AuthRead(pParse, pExpr, pNC->pSrcList);
  }
  return cnt!=1;
}

/*
** pExpr is a node that defines a function of some kind.  It might
** be a syntactic function like "count(x)" or it might be a function
** that implements an operator, like "a LIKE b".  
**
** This routine makes *pzName point to the name of the function and 
** *pnName hold the number of characters in the function name.
*/
static void getFunctionName(Expr *pExpr, const char **pzName, int *pnName){
  switch( pExpr->op ){
    case TK_FUNCTION: {
      *pzName = pExpr->token.z;
      *pnName = pExpr->token.n;
      break;
    }
    case TK_LIKE: {
      *pzName = "like";
      *pnName = 4;
      break;
    }
    case TK_GLOB: {
      *pzName = "glob";
      *pnName = 4;
      break;
    }
    case TK_CTIME: {
      *pzName = "current_time";
      *pnName = 12;
      break;
    }
    case TK_CDATE: {
      *pzName = "current_date";
      *pnName = 12;
      break;
    }
    case TK_CTIMESTAMP: {
      *pzName = "current_timestamp";
      *pnName = 17;
      break;
    }
  }
}

/*
** This routine is designed as an xFunc for walkExprTree().
**
** Resolve symbolic names into TK_COLUMN operators for the current
** node in the expression tree.  Return 0 to continue the search down
** the tree or 2 to abort the tree walk.
**
** This routine also does error checking and name resolution for
** function names.  The operator for aggregate functions is changed
** to TK_AGG_FUNCTION.
*/
static int nameResolverStep(void *pArg, Expr *pExpr){
  NameContext *pNC = (NameContext*)pArg;
  SrcList *pSrcList;
  Parse *pParse;

  if( pExpr==0 ) return 1;
  assert( pNC!=0 );
  pSrcList = pNC->pSrcList;
  pParse = pNC->pParse;

  if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return 1;
  ExprSetProperty(pExpr, EP_Resolved);
#ifndef NDEBUG
  if( pSrcList ){
    int i;
    for(i=0; i<pSrcList->nSrc; i++){
      assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab);
    }
  }
#endif
  switch( pExpr->op ){
    /* Double-quoted strings (ex: "abc") are used as identifiers if
    ** possible.  Otherwise they remain as strings.  Single-quoted
    ** strings (ex: 'abc') are always string literals.
    */
    case TK_STRING: {
      if( pExpr->token.z[0]=='\'' ) break;
      /* Fall thru into the TK_ID case if this is a double-quoted string */
    }
    /* A lone identifier is the name of a column.
    */
    case TK_ID: {
      lookupName(pParse, 0, 0, &pExpr->token, pNC, pExpr);
      return 1;
    }
  
    /* A table name and column name:     ID.ID
    ** Or a database, table and column:  ID.ID.ID
    */
    case TK_DOT: {
      Token *pColumn;
      Token *pTable;
      Token *pDb;
      Expr *pRight;

      /* if( pSrcList==0 ) break; */
      pRight = pExpr->pRight;
      if( pRight->op==TK_ID ){
        pDb = 0;
        pTable = &pExpr->pLeft->token;
        pColumn = &pRight->token;
      }else{
        assert( pRight->op==TK_DOT );
        pDb = &pExpr->pLeft->token;
        pTable = &pRight->pLeft->token;
        pColumn = &pRight->pRight->token;
      }
      lookupName(pParse, pDb, pTable, pColumn, pNC, pExpr);
      return 1;
    }

    /* Resolve function names
    */
    case TK_CTIME:
    case TK_CTIMESTAMP:
    case TK_CDATE:
    case TK_GLOB:
    case TK_LIKE:
    case TK_FUNCTION: {
      ExprList *pList = pExpr->pList;    /* The argument list */
      int n = pList ? pList->nExpr : 0;  /* Number of arguments */
      int no_such_func = 0;       /* True if no such function exists */
      int wrong_num_args = 0;     /* True if wrong number of arguments */
      int is_agg = 0;             /* True if is an aggregate function */
      int i;
      int nId;                    /* Number of characters in function name */
      const char *zId;            /* The function name. */
      FuncDef *pDef;              /* Information about the function */
      int enc = pParse->db->enc;  /* The database encoding */

      getFunctionName(pExpr, &zId, &nId);
      pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
      if( pDef==0 ){
        pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0);
        if( pDef==0 ){
          no_such_func = 1;
        }else{
          wrong_num_args = 1;
        }
      }else{
        is_agg = pDef->xFunc==0;
      }
      if( is_agg && !pNC->allowAgg ){
        sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
        pNC->nErr++;
        is_agg = 0;
      }else if( no_such_func ){
        sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
        pNC->nErr++;
      }else if( wrong_num_args ){
        sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
             nId, zId);
        pNC->nErr++;
      }
      if( is_agg ){
        pExpr->op = TK_AGG_FUNCTION;
        pNC->hasAgg = 1;
      }
      if( is_agg ) pNC->allowAgg = 0;
      for(i=0; pNC->nErr==0 && i<n; i++){
        walkExprTree(pList->a[i].pExpr, nameResolverStep, pNC);
      }
      if( is_agg ) pNC->allowAgg = 1;
      /* FIX ME:  Compute pExpr->affinity based on the expected return
      ** type of the function 
      */
      return is_agg;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_SELECT:
    case TK_EXISTS:
#endif
    case TK_IN: {
      if( pExpr->pSelect ){
        int nRef = pNC->nRef;
        sqlite3SelectResolve(pParse, pExpr->pSelect, pNC);
        assert( pNC->nRef>=nRef );
        if( nRef!=pNC->nRef ){
          ExprSetProperty(pExpr, EP_VarSelect);
        }
      }
    }
  }
  return 0;
}

/*
** This routine walks an expression tree and resolves references to
** table columns.  Nodes of the form ID.ID or ID resolve into an
** index to the table in the table list and a column offset.  The 
** Expr.opcode for such nodes is changed to TK_COLUMN.  The Expr.iTable
** value is changed to the index of the referenced table in pTabList
** plus the "base" value.  The base value will ultimately become the
** VDBE cursor number for a cursor that is pointing into the referenced
** table.  The Expr.iColumn value is changed to the index of the column 
** of the referenced table.  The Expr.iColumn value for the special
** ROWID column is -1.  Any INTEGER PRIMARY KEY column is tried as an
** alias for ROWID.
**
** Also resolve function names and check the functions for proper
** usage.  Make sure all function names are recognized and all functions
** have the correct number of arguments.  Leave an error message
** in pParse->zErrMsg if anything is amiss.  Return the number of errors.
**
** If the expression contains aggregate functions then set the EP_Agg
** property on the expression.
*/
int sqlite3ExprResolveNames(
  NameContext *pNC,       /* Namespace to resolve expressions in. */
  Expr *pExpr             /* The expression to be analyzed. */
){
  if( pExpr==0 ) return 0;
  walkExprTree(pExpr, nameResolverStep, pNC);
  if( pNC->nErr>0 ){
    ExprSetProperty(pExpr, EP_Error);
  }
  return ExprHasProperty(pExpr, EP_Error);
}

/*
** A pointer instance of this structure is used to pass information
** through walkExprTree into codeSubqueryStep().
*/
typedef struct QueryCoder QueryCoder;
struct QueryCoder {
  Parse *pParse;       /* The parsing context */
  NameContext *pNC;    /* Namespace of first enclosing query */
};


/*
** Generate code for subqueries and IN operators.
**
** IN operators comes in two forms:
**
**           expr IN (exprlist)
** and
**           expr IN (SELECT ...)
**
** The first form is handled by creating a set holding the list
** of allowed values.  The second form causes the SELECT to generate 
** a temporary table.
*/
#ifndef SQLITE_OMIT_SUBQUERY
void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
  int label = 0;                         /* Address after sub-select code */
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;

  /* If this is not a variable (correlated) select, then execute
  ** it only once. Unless this is part of a trigger program. In
  ** that case re-execute every time (this could be optimized).
  */
  if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
    int mem = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0);
    label = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_If, 0, label);
    sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, mem, 1);
  }

  if( pExpr->pSelect ){
    sqlite3VdbeAddOp(v, OP_AggContextPush, 0, 0);
  }

  switch( pExpr->op ){
    case TK_IN: {
      char affinity;
      KeyInfo keyInfo;
      int addr;        /* Address of OP_OpenTemp instruction */

      affinity = sqlite3ExprAffinity(pExpr->pLeft);

      /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
      ** expression it is handled the same way. A temporary table is 
      ** filled with single-field index keys representing the results
      ** from the SELECT or the <exprlist>.
      **
      ** If the 'x' expression is a column value, or the SELECT...
      ** statement returns a column value, then the affinity of that
      ** column is used to build the index keys. If both 'x' and the
      ** SELECT... statement are columns, then numeric affinity is used
      ** if either column has NUMERIC or INTEGER affinity. If neither
      ** 'x' nor the SELECT... statement are columns, then numeric affinity
      ** is used.
      */
      pExpr->iTable = pParse->nTab++;
      addr = sqlite3VdbeAddOp(v, OP_OpenTemp, pExpr->iTable, 0);
      memset(&keyInfo, 0, sizeof(keyInfo));
      keyInfo.nField = 1;
      sqlite3VdbeAddOp(v, OP_SetNumColumns, pExpr->iTable, 1);

      if( pExpr->pSelect ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into the temporary
        ** table allocated and opened above.
        */
        int iParm = pExpr->iTable +  (((int)affinity)<<16);
        ExprList *pEList;
        assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
        sqlite3Select(pParse, pExpr->pSelect, SRT_Set, iParm, 0, 0, 0, 0);
        pEList = pExpr->pSelect->pEList;
        if( pEList && pEList->nExpr>0 ){ 
          keyInfo.aColl[0] = binaryCompareCollSeq(pParse, pExpr->pLeft,
              pEList->a[0].pExpr);
        }
      }else if( pExpr->pList ){
        /* Case 2:     expr IN (exprlist)
        **
	** For each expression, build an index key from the evaluation and
        ** store it in the temporary table. If <expr> is a column, then use
        ** that columns affinity when building index keys. If <expr> is not
        ** a column, use numeric affinity.
        */
        int i;
        if( !affinity ){
          affinity = SQLITE_AFF_NUMERIC;
        }
        keyInfo.aColl[0] = pExpr->pLeft->pColl;

        /* Loop through each expression in <exprlist>. */
        for(i=0; i<pExpr->pList->nExpr; i++){
          Expr *pE2 = pExpr->pList->a[i].pExpr;

          /* Check that the expression is constant and valid. */
          if( !sqlite3ExprIsConstant(pE2) ){
            sqlite3ErrorMsg(pParse,
              "right-hand side of IN operator must be constant");
            return;
          }

          /* Evaluate the expression and insert it into the temp table */
          sqlite3ExprCode(pParse, pE2);
          sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1);
          sqlite3VdbeAddOp(v, OP_String8, 0, 0);
          sqlite3VdbeAddOp(v, OP_PutStrKey, pExpr->iTable, 0);
        }
      }
      sqlite3VdbeChangeP3(v, addr, (void *)&keyInfo, P3_KEYINFO);
      break;
    }

    case TK_EXISTS:
    case TK_SELECT: {
      /* This has to be a scalar SELECT.  Generate code to put the
      ** value of this select in a memory cell and record the number
      ** of the memory cell in iColumn.
      */
      int sop;
      Select *pSel;

      pExpr->iColumn = pParse->nMem++;
      pSel = pExpr->pSelect;
      if( pExpr->op==TK_SELECT ){
        sop = SRT_Mem;
      }else{
        static const Token one = { "1", 0, 1 };
        sop = SRT_Exists;
        sqlite3ExprListDelete(pSel->pEList);
        pSel->pEList = sqlite3ExprListAppend(0, 
                          sqlite3Expr(TK_INTEGER, 0, 0, &one), 0);
      }
      sqlite3Select(pParse, pSel, sop, pExpr->iColumn, 0, 0, 0, 0);
      break;
    }
  }

  if( pExpr->pSelect ){
    sqlite3VdbeAddOp(v, OP_AggContextPop, 0, 0);
  }
  if( label<0 ){
    sqlite3VdbeResolveLabel(v, label);
  }
  return;
}
#endif /* SQLITE_OMIT_SUBQUERY */

/*
** Generate an instruction that will put the integer describe by
** text z[0..n-1] on the stack.
*/
static void codeInteger(Vdbe *v, const char *z, int n){
  int i;
  if( sqlite3GetInt32(z, &i) ){
    sqlite3VdbeAddOp(v, OP_Integer, i, 0);
  }else if( sqlite3FitsIn64Bits(z) ){
    sqlite3VdbeOp3(v, OP_Integer, 0, 0, z, n);
  }else{
    sqlite3VdbeOp3(v, OP_Real, 0, 0, z, n);
  }
}

/*
** Generate code into the current Vdbe to evaluate the given
** expression and leave the result on the top of stack.
**
** This code depends on the fact that certain token values (ex: TK_EQ)
** are the same as opcode values (ex: OP_Eq) that implement the corresponding
** operation.  Special comments in vdbe.c and the mkopcodeh.awk script in
** the make process cause these values to align.  Assert()s in the code
** below verify that the numbers are aligned correctly.
*/
void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
  Vdbe *v = pParse->pVdbe;
  int op;
  if( v==0 ) return;
  if( pExpr==0 ){
    sqlite3VdbeAddOp(v, OP_String8, 0, 0);  /* Empty expression evals to NULL */
    return;
  }
  op = pExpr->op;
  switch( op ){
    case TK_COLUMN: {
      if( !pParse->fillAgg && pExpr->iAgg>=0 ){
        sqlite3VdbeAddOp(v, OP_AggGet, pExpr->iAggCtx, pExpr->iAgg);
      }else if( pExpr->iColumn>=0 ){
        sqlite3VdbeAddOp(v, OP_Column, pExpr->iTable, pExpr->iColumn);
#ifndef NDEBUG
        if( pExpr->span.z && pExpr->span.n>0 && pExpr->span.n<100 ){
          VdbeComment((v, "# %T", &pExpr->span));
        }
#endif
      }else{
        sqlite3VdbeAddOp(v, OP_Recno, pExpr->iTable, 0);
      }
      break;
    }
    case TK_INTEGER: {
      codeInteger(v, pExpr->token.z, pExpr->token.n);
      break;
    }
    case TK_FLOAT:
    case TK_STRING: {
      assert( TK_FLOAT==OP_Real );
      assert( TK_STRING==OP_String8 );
      sqlite3VdbeOp3(v, op, 0, 0, pExpr->token.z, pExpr->token.n);
      sqlite3VdbeDequoteP3(v, -1);
      break;
    }
#ifndef SQLITE_OMIT_BLOB_LITERAL
    case TK_BLOB: {
      assert( TK_BLOB==OP_HexBlob );
      sqlite3VdbeOp3(v, op, 0, 0, pExpr->token.z+1, pExpr->token.n-1);
      sqlite3VdbeDequoteP3(v, -1);
      break;
    }
#endif
    case TK_NULL: {
      sqlite3VdbeAddOp(v, OP_String8, 0, 0);
      break;
    }
    case TK_VARIABLE: {
      sqlite3VdbeAddOp(v, OP_Variable, pExpr->iTable, 0);
      if( pExpr->token.n>1 ){
        sqlite3VdbeChangeP3(v, -1, pExpr->token.z, pExpr->token.n);
      }
      break;
    }
    case TK_REGISTER: {
      sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iTable, 0);
      break;
    }
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_NE:
    case TK_EQ: {
      assert( TK_LT==OP_Lt );
      assert( TK_LE==OP_Le );
      assert( TK_GT==OP_Gt );
      assert( TK_GE==OP_Ge );
      assert( TK_EQ==OP_Eq );
      assert( TK_NE==OP_Ne );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3ExprCode(pParse, pExpr->pRight);
      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, 0, 0);
      break;
    }
    case TK_AND:
    case TK_OR:
    case TK_PLUS:
    case TK_STAR:
    case TK_MINUS:
    case TK_REM:
    case TK_BITAND:
    case TK_BITOR:
    case TK_SLASH:
    case TK_LSHIFT:
    case TK_RSHIFT: 
    case TK_CONCAT: {
      assert( TK_AND==OP_And );
      assert( TK_OR==OP_Or );
      assert( TK_PLUS==OP_Add );
      assert( TK_MINUS==OP_Subtract );
      assert( TK_REM==OP_Remainder );
      assert( TK_BITAND==OP_BitAnd );
      assert( TK_BITOR==OP_BitOr );
      assert( TK_SLASH==OP_Divide );
      assert( TK_LSHIFT==OP_ShiftLeft );
      assert( TK_RSHIFT==OP_ShiftRight );
      assert( TK_CONCAT==OP_Concat );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3ExprCode(pParse, pExpr->pRight);
      sqlite3VdbeAddOp(v, op, 0, 0);
      break;
    }
    case TK_UMINUS: {
      Expr *pLeft = pExpr->pLeft;
      assert( pLeft );
      if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
        Token *p = &pLeft->token;
        char *z = sqliteMalloc( p->n + 2 );
        sprintf(z, "-%.*s", p->n, p->z);
        if( pLeft->op==TK_FLOAT ){
          sqlite3VdbeOp3(v, OP_Real, 0, 0, z, p->n+1);
        }else{
          codeInteger(v, z, p->n+1);
        }
        sqliteFree(z);
        break;
      }
      /* Fall through into TK_NOT */
    }
    case TK_BITNOT:
    case TK_NOT: {
      assert( TK_BITNOT==OP_BitNot );
      assert( TK_NOT==OP_Not );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3VdbeAddOp(v, op, 0, 0);
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      int dest;
      assert( TK_ISNULL==OP_IsNull );
      assert( TK_NOTNULL==OP_NotNull );
      sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
      sqlite3ExprCode(pParse, pExpr->pLeft);
      dest = sqlite3VdbeCurrentAddr(v) + 2;
      sqlite3VdbeAddOp(v, op, 1, dest);
      sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);
      break;
    }
    case TK_AGG_FUNCTION: {
      sqlite3VdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg);
      break;
    }
    case TK_CDATE:
    case TK_CTIME:
    case TK_CTIMESTAMP:
    case TK_GLOB:
    case TK_LIKE:
    case TK_FUNCTION: {
      ExprList *pList = pExpr->pList;
      int nExpr = pList ? pList->nExpr : 0;
      FuncDef *pDef;
      int nId;
      const char *zId;
      int p2 = 0;
      int i;
      u8 enc = pParse->db->enc;
      CollSeq *pColl = 0;
      getFunctionName(pExpr, &zId, &nId);
      pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0);
      assert( pDef!=0 );
      nExpr = sqlite3ExprCodeExprList(pParse, pList);
      for(i=0; i<nExpr && i<32; i++){
        if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){
          p2 |= (1<<i);
        }
        if( pDef->needCollSeq && !pColl ){
          pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
        }
      }
      if( pDef->needCollSeq ){
        if( !pColl ) pColl = pParse->db->pDfltColl; 
        sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
      }
      sqlite3VdbeOp3(v, OP_Function, nExpr, p2, (char*)pDef, P3_FUNCDEF);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT: {
      sqlite3CodeSubselect(pParse, pExpr);
      sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0);
      VdbeComment((v, "# load subquery result"));
      break;
    }
    case TK_IN: {
      int addr;
      char affinity;
      sqlite3CodeSubselect(pParse, pExpr);

      /* Figure out the affinity to use to create a key from the results
      ** of the expression. affinityStr stores a static string suitable for
      ** P3 of OP_MakeRecord.
      */
      affinity = comparisonAffinity(pExpr);

      sqlite3VdbeAddOp(v, OP_Integer, 1, 0);

      /* Code the <expr> from "<expr> IN (...)". The temporary table
      ** pExpr->iTable contains the values that make up the (...) set.
      */
      sqlite3ExprCode(pParse, pExpr->pLeft);
      addr = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp(v, OP_NotNull, -1, addr+4);            /* addr + 0 */
      sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
      sqlite3VdbeAddOp(v, OP_String8, 0, 0);
      sqlite3VdbeAddOp(v, OP_Goto, 0, addr+7);
      sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1);   /* addr + 4 */
      sqlite3VdbeAddOp(v, OP_Found, pExpr->iTable, addr+7);
      sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);                  /* addr + 6 */

      break;
    }
#endif
    case TK_BETWEEN: {
      Expr *pLeft = pExpr->pLeft;
      struct ExprList_item *pLItem = pExpr->pList->a;
      Expr *pRight = pLItem->pExpr;
      sqlite3ExprCode(pParse, pLeft);
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Ge, 0, 0);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      pLItem++;
      pRight = pLItem->pExpr;
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Le, 0, 0);
      sqlite3VdbeAddOp(v, OP_And, 0, 0);
      break;
    }
    case TK_UPLUS:
    case TK_AS: {
      sqlite3ExprCode(pParse, pExpr->pLeft);
      break;
    }
    case TK_CASE: {
      int expr_end_label;
      int jumpInst;
      int addr;
      int nExpr;
      int i;
      ExprList *pEList;
      struct ExprList_item *aListelem;

      assert(pExpr->pList);
      assert((pExpr->pList->nExpr % 2) == 0);
      assert(pExpr->pList->nExpr > 0);
      pEList = pExpr->pList;
      aListelem = pEList->a;
      nExpr = pEList->nExpr;
      expr_end_label = sqlite3VdbeMakeLabel(v);
      if( pExpr->pLeft ){
        sqlite3ExprCode(pParse, pExpr->pLeft);
      }
      for(i=0; i<nExpr; i=i+2){
        sqlite3ExprCode(pParse, aListelem[i].pExpr);
        if( pExpr->pLeft ){
          sqlite3VdbeAddOp(v, OP_Dup, 1, 1);
          jumpInst = codeCompare(pParse, pExpr->pLeft, aListelem[i].pExpr,
                                 OP_Ne, 0, 1);
          sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
        }else{
          jumpInst = sqlite3VdbeAddOp(v, OP_IfNot, 1, 0);
        }
        sqlite3ExprCode(pParse, aListelem[i+1].pExpr);
        sqlite3VdbeAddOp(v, OP_Goto, 0, expr_end_label);
        addr = sqlite3VdbeCurrentAddr(v);
        sqlite3VdbeChangeP2(v, jumpInst, addr);
      }
      if( pExpr->pLeft ){
        sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      }
      if( pExpr->pRight ){
        sqlite3ExprCode(pParse, pExpr->pRight);
      }else{
        sqlite3VdbeAddOp(v, OP_String8, 0, 0);
      }
      sqlite3VdbeResolveLabel(v, expr_end_label);
      break;
    }
#ifndef SQLITE_OMIT_TRIGGER
    case TK_RAISE: {
      if( !pParse->trigStack ){
        sqlite3ErrorMsg(pParse,
                       "RAISE() may only be used within a trigger-program");
	return;
      }
      if( pExpr->iColumn!=OE_Ignore ){
         assert( pExpr->iColumn==OE_Rollback ||
                 pExpr->iColumn == OE_Abort ||
                 pExpr->iColumn == OE_Fail );
         sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn,
                        pExpr->token.z, pExpr->token.n);
         sqlite3VdbeDequoteP3(v, -1);
      } else {
         assert( pExpr->iColumn == OE_Ignore );
         sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
         sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
         VdbeComment((v, "# raise(IGNORE)"));
      }
    }
#endif
    break;
  }
}

#ifndef SQLITE_OMIT_TRIGGER
/*
** Generate code that evalutes the given expression and leaves the result
** on the stack.  See also sqlite3ExprCode().
**
** This routine might also cache the result and modify the pExpr tree
** so that it will make use of the cached result on subsequent evaluations
** rather than evaluate the whole expression again.  Trivial expressions are
** not cached.  If the expression is cached, its result is stored in a 
** memory location.
*/
void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr){
  Vdbe *v = pParse->pVdbe;
  int iMem;
  int addr1, addr2;
  if( v==0 ) return;
  addr1 = sqlite3VdbeCurrentAddr(v);
  sqlite3ExprCode(pParse, pExpr);
  addr2 = sqlite3VdbeCurrentAddr(v);
  if( addr2>addr1+1 || sqlite3VdbeGetOp(v, addr1)->opcode==OP_Function ){
    iMem = pExpr->iTable = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemStore, iMem, 0);
    pExpr->op = TK_REGISTER;
  }
}
#endif

/*
** Generate code that pushes the value of every element of the given
** expression list onto the stack.
**
** Return the number of elements pushed onto the stack.
*/
int sqlite3ExprCodeExprList(
  Parse *pParse,     /* Parsing context */
  ExprList *pList    /* The expression list to be coded */
){
  struct ExprList_item *pItem;
  int i, n;
  Vdbe *v;
  if( pList==0 ) return 0;
  v = sqlite3GetVdbe(pParse);
  n = pList->nExpr;
  for(pItem=pList->a, i=0; i<n; i++, pItem++){
    sqlite3ExprCode(pParse, pItem->pExpr);
  }
  return n;
}

/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is true but execution
** continues straight thru if the expression is false.
**
** If the expression evaluates to NULL (neither true nor false), then
** take the jump if the jumpIfNull flag is true.
**
** This code depends on the fact that certain token values (ex: TK_EQ)
** are the same as opcode values (ex: OP_Eq) that implement the corresponding
** operation.  Special comments in vdbe.c and the mkopcodeh.awk script in
** the make process cause these values to align.  Assert()s in the code
** below verify that the numbers are aligned correctly.
*/
void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
  Vdbe *v = pParse->pVdbe;
  int op = 0;
  if( v==0 || pExpr==0 ) return;
  op = pExpr->op;
  switch( op ){
    case TK_AND: {
      int d2 = sqlite3VdbeMakeLabel(v);
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2, !jumpIfNull);
      sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
      sqlite3VdbeResolveLabel(v, d2);
      break;
    }
    case TK_OR: {
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
      sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
      break;
    }
    case TK_NOT: {
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
      break;
    }
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_NE:
    case TK_EQ: {
      assert( TK_LT==OP_Lt );
      assert( TK_LE==OP_Le );
      assert( TK_GT==OP_Gt );
      assert( TK_GE==OP_Ge );
      assert( TK_EQ==OP_Eq );
      assert( TK_NE==OP_Ne );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3ExprCode(pParse, pExpr->pRight);
      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      assert( TK_ISNULL==OP_IsNull );
      assert( TK_NOTNULL==OP_NotNull );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3VdbeAddOp(v, op, 1, dest);
      break;
    }
    case TK_BETWEEN: {
      /* The expression "x BETWEEN y AND z" is implemented as:
      **
      ** 1 IF (x < y) GOTO 3
      ** 2 IF (x <= z) GOTO <dest>
      ** 3 ...
      */
      int addr;
      Expr *pLeft = pExpr->pLeft;
      Expr *pRight = pExpr->pList->a[0].pExpr;
      sqlite3ExprCode(pParse, pLeft);
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      sqlite3ExprCode(pParse, pRight);
      addr = codeCompare(pParse, pLeft, pRight, OP_Lt, 0, !jumpIfNull);

      pRight = pExpr->pList->a[1].pExpr;
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Le, dest, jumpIfNull);

      sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
      sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));
      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      break;
    }
    default: {
      sqlite3ExprCode(pParse, pExpr);
      sqlite3VdbeAddOp(v, OP_If, jumpIfNull, dest);
      break;
    }
  }
}

/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is false but execution
** continues straight thru if the expression is true.
**
** If the expression evaluates to NULL (neither true nor false) then
** jump if jumpIfNull is true or fall through if jumpIfNull is false.
*/
void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
  Vdbe *v = pParse->pVdbe;
  int op = 0;
  if( v==0 || pExpr==0 ) return;

  /* The value of pExpr->op and op are related as follows:
  **
  **       pExpr->op            op
  **       ---------          ----------
  **       TK_ISNULL          OP_NotNull
  **       TK_NOTNULL         OP_IsNull
  **       TK_NE              OP_Eq
  **       TK_EQ              OP_Ne
  **       TK_GT              OP_Le
  **       TK_LE              OP_Gt
  **       TK_GE              OP_Lt
  **       TK_LT              OP_Ge
  **
  ** For other values of pExpr->op, op is undefined and unused.
  ** The value of TK_ and OP_ constants are arranged such that we
  ** can compute the mapping above using the following expression.
  ** Assert()s verify that the computation is correct.
  */
  op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);

  /* Verify correct alignment of TK_ and OP_ constants
  */
  assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
  assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
  assert( pExpr->op!=TK_NE || op==OP_Eq );
  assert( pExpr->op!=TK_EQ || op==OP_Ne );
  assert( pExpr->op!=TK_LT || op==OP_Ge );
  assert( pExpr->op!=TK_LE || op==OP_Gt );
  assert( pExpr->op!=TK_GT || op==OP_Le );
  assert( pExpr->op!=TK_GE || op==OP_Lt );

  switch( pExpr->op ){
    case TK_AND: {
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
      break;
    }
    case TK_OR: {
      int d2 = sqlite3VdbeMakeLabel(v);
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, !jumpIfNull);
      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
      sqlite3VdbeResolveLabel(v, d2);
      break;
    }
    case TK_NOT: {
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
      break;
    }
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_NE:
    case TK_EQ: {
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3ExprCode(pParse, pExpr->pRight);
      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3VdbeAddOp(v, op, 1, dest);
      break;
    }
    case TK_BETWEEN: {
      /* The expression is "x BETWEEN y AND z". It is implemented as:
      **
      ** 1 IF (x >= y) GOTO 3
      ** 2 GOTO <dest>
      ** 3 IF (x > z) GOTO <des