src/sqlite3.h
author Volker Birk <vb@pep-project.org>
Mon, 06 Jun 2016 17:35:13 +0200
changeset 716 498156bf9993
parent 491 d32c60ada438
child 1513 e7f7e42385b5
permissions -rw-r--r--
new sqlite3
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/*
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** 2001 September 15
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**
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** The author disclaims copyright to this source code.  In place of
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** a legal notice, here is a blessing:
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**
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**    May you do good and not evil.
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**    May you find forgiveness for yourself and forgive others.
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**    May you share freely, never taking more than you give.
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**
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*************************************************************************
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** This header file defines the interface that the SQLite library
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** presents to client programs.  If a C-function, structure, datatype,
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** or constant definition does not appear in this file, then it is
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** not a published API of SQLite, is subject to change without
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** notice, and should not be referenced by programs that use SQLite.
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**
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** Some of the definitions that are in this file are marked as
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** "experimental".  Experimental interfaces are normally new
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** features recently added to SQLite.  We do not anticipate changes
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** to experimental interfaces but reserve the right to make minor changes
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** if experience from use "in the wild" suggest such changes are prudent.
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**
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** The official C-language API documentation for SQLite is derived
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** from comments in this file.  This file is the authoritative source
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** on how SQLite interfaces are supposed to operate.
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**
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** The name of this file under configuration management is "sqlite.h.in".
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** The makefile makes some minor changes to this file (such as inserting
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** the version number) and changes its name to "sqlite3.h" as
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** part of the build process.
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*/
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#ifndef _SQLITE3_H_
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#define _SQLITE3_H_
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#include <stdarg.h>     /* Needed for the definition of va_list */
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/*
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** Make sure we can call this stuff from C++.
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*/
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#ifdef __cplusplus
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extern "C" {
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#endif
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/*
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** Provide the ability to override linkage features of the interface.
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*/
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#ifndef SQLITE_EXTERN
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# define SQLITE_EXTERN extern
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#endif
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#ifndef SQLITE_API
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# define SQLITE_API
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#endif
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#ifndef SQLITE_CDECL
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# define SQLITE_CDECL
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#endif
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#ifndef SQLITE_STDCALL
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# define SQLITE_STDCALL
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#endif
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/*
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** These no-op macros are used in front of interfaces to mark those
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** interfaces as either deprecated or experimental.  New applications
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** should not use deprecated interfaces - they are supported for backwards
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** compatibility only.  Application writers should be aware that
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** experimental interfaces are subject to change in point releases.
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**
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** These macros used to resolve to various kinds of compiler magic that
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** would generate warning messages when they were used.  But that
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** compiler magic ended up generating such a flurry of bug reports
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** that we have taken it all out and gone back to using simple
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** noop macros.
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*/
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#define SQLITE_DEPRECATED
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#define SQLITE_EXPERIMENTAL
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/*
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** Ensure these symbols were not defined by some previous header file.
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*/
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#ifdef SQLITE_VERSION
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# undef SQLITE_VERSION
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#endif
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#ifdef SQLITE_VERSION_NUMBER
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# undef SQLITE_VERSION_NUMBER
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#endif
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/*
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** CAPI3REF: Compile-Time Library Version Numbers
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**
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** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
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** evaluates to a string literal that is the SQLite version in the
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** format "X.Y.Z" where X is the major version number (always 3 for
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** SQLite3) and Y is the minor version number and Z is the release number.)^
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** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
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** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
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** numbers used in [SQLITE_VERSION].)^
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** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
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** be larger than the release from which it is derived.  Either Y will
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** be held constant and Z will be incremented or else Y will be incremented
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** and Z will be reset to zero.
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**
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** Since version 3.6.18, SQLite source code has been stored in the
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** <a href="http://www.fossil-scm.org/">Fossil configuration management
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** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
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** a string which identifies a particular check-in of SQLite
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** within its configuration management system.  ^The SQLITE_SOURCE_ID
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** string contains the date and time of the check-in (UTC) and an SHA1
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** hash of the entire source tree.
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**
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** See also: [sqlite3_libversion()],
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** [sqlite3_libversion_number()], [sqlite3_sourceid()],
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** [sqlite_version()] and [sqlite_source_id()].
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*/
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#define SQLITE_VERSION        "3.13.0"
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#define SQLITE_VERSION_NUMBER 3013000
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#define SQLITE_SOURCE_ID      "2016-05-18 10:57:30 fc49f556e48970561d7ab6a2f24fdd7d9eb81ff2"
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/*
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** CAPI3REF: Run-Time Library Version Numbers
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** KEYWORDS: sqlite3_version, sqlite3_sourceid
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**
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** These interfaces provide the same information as the [SQLITE_VERSION],
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** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
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** but are associated with the library instead of the header file.  ^(Cautious
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** programmers might include assert() statements in their application to
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** verify that values returned by these interfaces match the macros in
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** the header, and thus ensure that the application is
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** compiled with matching library and header files.
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**
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** <blockquote><pre>
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** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
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** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
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** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
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** </pre></blockquote>)^
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**
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** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
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** macro.  ^The sqlite3_libversion() function returns a pointer to the
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** to the sqlite3_version[] string constant.  The sqlite3_libversion()
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** function is provided for use in DLLs since DLL users usually do not have
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** direct access to string constants within the DLL.  ^The
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** sqlite3_libversion_number() function returns an integer equal to
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** [SQLITE_VERSION_NUMBER].  ^The sqlite3_sourceid() function returns 
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** a pointer to a string constant whose value is the same as the 
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** [SQLITE_SOURCE_ID] C preprocessor macro.
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**
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** See also: [sqlite_version()] and [sqlite_source_id()].
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*/
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SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
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SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void);
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SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void);
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SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void);
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/*
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** CAPI3REF: Run-Time Library Compilation Options Diagnostics
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**
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** ^The sqlite3_compileoption_used() function returns 0 or 1 
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** indicating whether the specified option was defined at 
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** compile time.  ^The SQLITE_ prefix may be omitted from the 
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** option name passed to sqlite3_compileoption_used().  
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**
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** ^The sqlite3_compileoption_get() function allows iterating
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** over the list of options that were defined at compile time by
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** returning the N-th compile time option string.  ^If N is out of range,
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** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_ 
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** prefix is omitted from any strings returned by 
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** sqlite3_compileoption_get().
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**
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** ^Support for the diagnostic functions sqlite3_compileoption_used()
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** and sqlite3_compileoption_get() may be omitted by specifying the 
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** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
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**
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** See also: SQL functions [sqlite_compileoption_used()] and
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** [sqlite_compileoption_get()] and the [compile_options pragma].
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*/
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#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
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SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName);
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SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N);
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#endif
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/*
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** CAPI3REF: Test To See If The Library Is Threadsafe
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**
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** ^The sqlite3_threadsafe() function returns zero if and only if
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** SQLite was compiled with mutexing code omitted due to the
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** [SQLITE_THREADSAFE] compile-time option being set to 0.
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**
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** SQLite can be compiled with or without mutexes.  When
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** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
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** are enabled and SQLite is threadsafe.  When the
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** [SQLITE_THREADSAFE] macro is 0, 
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** the mutexes are omitted.  Without the mutexes, it is not safe
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** to use SQLite concurrently from more than one thread.
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**
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** Enabling mutexes incurs a measurable performance penalty.
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** So if speed is of utmost importance, it makes sense to disable
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** the mutexes.  But for maximum safety, mutexes should be enabled.
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** ^The default behavior is for mutexes to be enabled.
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**
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** This interface can be used by an application to make sure that the
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** version of SQLite that it is linking against was compiled with
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** the desired setting of the [SQLITE_THREADSAFE] macro.
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**
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** This interface only reports on the compile-time mutex setting
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** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
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** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
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** can be fully or partially disabled using a call to [sqlite3_config()]
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** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
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** or [SQLITE_CONFIG_SERIALIZED].  ^(The return value of the
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** sqlite3_threadsafe() function shows only the compile-time setting of
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** thread safety, not any run-time changes to that setting made by
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** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
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** is unchanged by calls to sqlite3_config().)^
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**
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** See the [threading mode] documentation for additional information.
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*/
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SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void);
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/*
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** CAPI3REF: Database Connection Handle
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** KEYWORDS: {database connection} {database connections}
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**
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** Each open SQLite database is represented by a pointer to an instance of
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** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
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** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
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** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
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** and [sqlite3_close_v2()] are its destructors.  There are many other
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** interfaces (such as
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** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
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** [sqlite3_busy_timeout()] to name but three) that are methods on an
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** sqlite3 object.
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*/
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typedef struct sqlite3 sqlite3;
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/*
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** CAPI3REF: 64-Bit Integer Types
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** KEYWORDS: sqlite_int64 sqlite_uint64
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**
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** Because there is no cross-platform way to specify 64-bit integer types
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** SQLite includes typedefs for 64-bit signed and unsigned integers.
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**
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** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
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** The sqlite_int64 and sqlite_uint64 types are supported for backwards
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** compatibility only.
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**
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** ^The sqlite3_int64 and sqlite_int64 types can store integer values
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** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
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** sqlite3_uint64 and sqlite_uint64 types can store integer values 
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** between 0 and +18446744073709551615 inclusive.
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*/
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#ifdef SQLITE_INT64_TYPE
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  typedef SQLITE_INT64_TYPE sqlite_int64;
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  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
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#elif defined(_MSC_VER) || defined(__BORLANDC__)
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  typedef __int64 sqlite_int64;
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  typedef unsigned __int64 sqlite_uint64;
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#else
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  typedef long long int sqlite_int64;
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  typedef unsigned long long int sqlite_uint64;
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#endif
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typedef sqlite_int64 sqlite3_int64;
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typedef sqlite_uint64 sqlite3_uint64;
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/*
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** If compiling for a processor that lacks floating point support,
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** substitute integer for floating-point.
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*/
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#ifdef SQLITE_OMIT_FLOATING_POINT
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# define double sqlite3_int64
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#endif
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/*
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** CAPI3REF: Closing A Database Connection
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** DESTRUCTOR: sqlite3
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**
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** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
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** for the [sqlite3] object.
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** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
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** the [sqlite3] object is successfully destroyed and all associated
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** resources are deallocated.
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**
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** ^If the database connection is associated with unfinalized prepared
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** statements or unfinished sqlite3_backup objects then sqlite3_close()
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** will leave the database connection open and return [SQLITE_BUSY].
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** ^If sqlite3_close_v2() is called with unfinalized prepared statements
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** and/or unfinished sqlite3_backups, then the database connection becomes
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** an unusable "zombie" which will automatically be deallocated when the
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** last prepared statement is finalized or the last sqlite3_backup is
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** finished.  The sqlite3_close_v2() interface is intended for use with
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** host languages that are garbage collected, and where the order in which
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** destructors are called is arbitrary.
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**
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** Applications should [sqlite3_finalize | finalize] all [prepared statements],
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** [sqlite3_blob_close | close] all [BLOB handles], and 
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** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
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** with the [sqlite3] object prior to attempting to close the object.  ^If
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** sqlite3_close_v2() is called on a [database connection] that still has
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** outstanding [prepared statements], [BLOB handles], and/or
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** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
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** of resources is deferred until all [prepared statements], [BLOB handles],
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** and [sqlite3_backup] objects are also destroyed.
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**
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** ^If an [sqlite3] object is destroyed while a transaction is open,
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** the transaction is automatically rolled back.
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**
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** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
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** must be either a NULL
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** pointer or an [sqlite3] object pointer obtained
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** from [sqlite3_open()], [sqlite3_open16()], or
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** [sqlite3_open_v2()], and not previously closed.
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** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
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** argument is a harmless no-op.
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*/
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SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*);
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SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*);
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/*
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** The type for a callback function.
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** This is legacy and deprecated.  It is included for historical
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** compatibility and is not documented.
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*/
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typedef int (*sqlite3_callback)(void*,int,char**, char**);
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/*
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** CAPI3REF: One-Step Query Execution Interface
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** METHOD: sqlite3
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**
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** The sqlite3_exec() interface is a convenience wrapper around
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** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
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** that allows an application to run multiple statements of SQL
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** without having to use a lot of C code. 
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**
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** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
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** semicolon-separate SQL statements passed into its 2nd argument,
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** in the context of the [database connection] passed in as its 1st
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** argument.  ^If the callback function of the 3rd argument to
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** sqlite3_exec() is not NULL, then it is invoked for each result row
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** coming out of the evaluated SQL statements.  ^The 4th argument to
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** sqlite3_exec() is relayed through to the 1st argument of each
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** callback invocation.  ^If the callback pointer to sqlite3_exec()
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** is NULL, then no callback is ever invoked and result rows are
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** ignored.
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**
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** ^If an error occurs while evaluating the SQL statements passed into
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** sqlite3_exec(), then execution of the current statement stops and
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** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
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** is not NULL then any error message is written into memory obtained
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** from [sqlite3_malloc()] and passed back through the 5th parameter.
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** To avoid memory leaks, the application should invoke [sqlite3_free()]
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** on error message strings returned through the 5th parameter of
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** sqlite3_exec() after the error message string is no longer needed.
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** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
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** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
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** NULL before returning.
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**
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** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
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** routine returns SQLITE_ABORT without invoking the callback again and
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** without running any subsequent SQL statements.
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**
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** ^The 2nd argument to the sqlite3_exec() callback function is the
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** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
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** callback is an array of pointers to strings obtained as if from
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** [sqlite3_column_text()], one for each column.  ^If an element of a
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** result row is NULL then the corresponding string pointer for the
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** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
vb@130
   365
** sqlite3_exec() callback is an array of pointers to strings where each
vb@130
   366
** entry represents the name of corresponding result column as obtained
vb@130
   367
** from [sqlite3_column_name()].
vb@130
   368
**
vb@130
   369
** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
vb@130
   370
** to an empty string, or a pointer that contains only whitespace and/or 
vb@130
   371
** SQL comments, then no SQL statements are evaluated and the database
vb@130
   372
** is not changed.
vb@130
   373
**
vb@130
   374
** Restrictions:
vb@130
   375
**
vb@130
   376
** <ul>
Edouard@491
   377
** <li> The application must ensure that the 1st parameter to sqlite3_exec()
vb@130
   378
**      is a valid and open [database connection].
vb@130
   379
** <li> The application must not close the [database connection] specified by
vb@130
   380
**      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
vb@130
   381
** <li> The application must not modify the SQL statement text passed into
vb@130
   382
**      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
vb@130
   383
** </ul>
vb@130
   384
*/
Edouard@491
   385
SQLITE_API int SQLITE_STDCALL sqlite3_exec(
vb@130
   386
  sqlite3*,                                  /* An open database */
vb@130
   387
  const char *sql,                           /* SQL to be evaluated */
vb@130
   388
  int (*callback)(void*,int,char**,char**),  /* Callback function */
vb@130
   389
  void *,                                    /* 1st argument to callback */
vb@130
   390
  char **errmsg                              /* Error msg written here */
vb@130
   391
);
vb@130
   392
vb@130
   393
/*
vb@130
   394
** CAPI3REF: Result Codes
vb@130
   395
** KEYWORDS: {result code definitions}
vb@130
   396
**
vb@130
   397
** Many SQLite functions return an integer result code from the set shown
vb@130
   398
** here in order to indicate success or failure.
vb@130
   399
**
vb@130
   400
** New error codes may be added in future versions of SQLite.
vb@130
   401
**
vb@130
   402
** See also: [extended result code definitions]
vb@130
   403
*/
vb@130
   404
#define SQLITE_OK           0   /* Successful result */
vb@130
   405
/* beginning-of-error-codes */
vb@130
   406
#define SQLITE_ERROR        1   /* SQL error or missing database */
vb@130
   407
#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
vb@130
   408
#define SQLITE_PERM         3   /* Access permission denied */
vb@130
   409
#define SQLITE_ABORT        4   /* Callback routine requested an abort */
vb@130
   410
#define SQLITE_BUSY         5   /* The database file is locked */
vb@130
   411
#define SQLITE_LOCKED       6   /* A table in the database is locked */
vb@130
   412
#define SQLITE_NOMEM        7   /* A malloc() failed */
vb@130
   413
#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
vb@130
   414
#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
vb@130
   415
#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
vb@130
   416
#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
vb@130
   417
#define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
vb@130
   418
#define SQLITE_FULL        13   /* Insertion failed because database is full */
vb@130
   419
#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
vb@130
   420
#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
vb@130
   421
#define SQLITE_EMPTY       16   /* Database is empty */
vb@130
   422
#define SQLITE_SCHEMA      17   /* The database schema changed */
vb@130
   423
#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
vb@130
   424
#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
vb@130
   425
#define SQLITE_MISMATCH    20   /* Data type mismatch */
vb@130
   426
#define SQLITE_MISUSE      21   /* Library used incorrectly */
vb@130
   427
#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
vb@130
   428
#define SQLITE_AUTH        23   /* Authorization denied */
vb@130
   429
#define SQLITE_FORMAT      24   /* Auxiliary database format error */
vb@130
   430
#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
vb@130
   431
#define SQLITE_NOTADB      26   /* File opened that is not a database file */
vb@130
   432
#define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
vb@130
   433
#define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
vb@130
   434
#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
vb@130
   435
#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
vb@130
   436
/* end-of-error-codes */
vb@130
   437
vb@130
   438
/*
vb@130
   439
** CAPI3REF: Extended Result Codes
vb@130
   440
** KEYWORDS: {extended result code definitions}
vb@130
   441
**
vb@130
   442
** In its default configuration, SQLite API routines return one of 30 integer
vb@130
   443
** [result codes].  However, experience has shown that many of
vb@130
   444
** these result codes are too coarse-grained.  They do not provide as
vb@130
   445
** much information about problems as programmers might like.  In an effort to
vb@130
   446
** address this, newer versions of SQLite (version 3.3.8 and later) include
vb@130
   447
** support for additional result codes that provide more detailed information
vb@130
   448
** about errors. These [extended result codes] are enabled or disabled
vb@130
   449
** on a per database connection basis using the
vb@130
   450
** [sqlite3_extended_result_codes()] API.  Or, the extended code for
vb@130
   451
** the most recent error can be obtained using
vb@130
   452
** [sqlite3_extended_errcode()].
vb@130
   453
*/
vb@130
   454
#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
vb@130
   455
#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
vb@130
   456
#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
vb@130
   457
#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
vb@130
   458
#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
vb@130
   459
#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
vb@130
   460
#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
vb@130
   461
#define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
vb@130
   462
#define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
vb@130
   463
#define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
vb@130
   464
#define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
vb@130
   465
#define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
vb@130
   466
#define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
vb@130
   467
#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
vb@130
   468
#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
vb@130
   469
#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
vb@130
   470
#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
vb@130
   471
#define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
vb@130
   472
#define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
vb@130
   473
#define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
vb@130
   474
#define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
vb@130
   475
#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
vb@130
   476
#define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
vb@130
   477
#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
vb@130
   478
#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
vb@130
   479
#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
Edouard@491
   480
#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
Edouard@491
   481
#define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
vb@130
   482
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
vb@130
   483
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
vb@130
   484
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
vb@130
   485
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
vb@130
   486
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
vb@130
   487
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
vb@130
   488
#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
vb@130
   489
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
vb@130
   490
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
vb@130
   491
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
vb@130
   492
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
vb@130
   493
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
vb@130
   494
#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
vb@130
   495
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
vb@130
   496
#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
vb@130
   497
#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
vb@130
   498
#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
vb@130
   499
#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
vb@130
   500
#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
vb@130
   501
#define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))
vb@130
   502
#define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))
vb@130
   503
#define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
vb@130
   504
#define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))
vb@130
   505
#define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
vb@130
   506
#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
vb@130
   507
#define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
Edouard@491
   508
#define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))
vb@130
   509
vb@130
   510
/*
vb@130
   511
** CAPI3REF: Flags For File Open Operations
vb@130
   512
**
vb@130
   513
** These bit values are intended for use in the
vb@130
   514
** 3rd parameter to the [sqlite3_open_v2()] interface and
vb@130
   515
** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
vb@130
   516
*/
vb@130
   517
#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
vb@130
   518
#define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
vb@130
   519
#define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
vb@130
   520
#define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
vb@130
   521
#define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
vb@130
   522
#define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
vb@130
   523
#define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
vb@130
   524
#define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
vb@130
   525
#define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
vb@130
   526
#define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
vb@130
   527
#define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
vb@130
   528
#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
vb@130
   529
#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
vb@130
   530
#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
vb@130
   531
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
vb@130
   532
#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
vb@130
   533
#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
vb@130
   534
#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
vb@130
   535
#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
vb@130
   536
#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
vb@130
   537
vb@130
   538
/* Reserved:                         0x00F00000 */
vb@130
   539
vb@130
   540
/*
vb@130
   541
** CAPI3REF: Device Characteristics
vb@130
   542
**
vb@130
   543
** The xDeviceCharacteristics method of the [sqlite3_io_methods]
vb@130
   544
** object returns an integer which is a vector of these
vb@130
   545
** bit values expressing I/O characteristics of the mass storage
vb@130
   546
** device that holds the file that the [sqlite3_io_methods]
vb@130
   547
** refers to.
vb@130
   548
**
vb@130
   549
** The SQLITE_IOCAP_ATOMIC property means that all writes of
vb@130
   550
** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
vb@130
   551
** mean that writes of blocks that are nnn bytes in size and
vb@130
   552
** are aligned to an address which is an integer multiple of
vb@130
   553
** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
vb@130
   554
** that when data is appended to a file, the data is appended
vb@130
   555
** first then the size of the file is extended, never the other
vb@130
   556
** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
vb@130
   557
** information is written to disk in the same order as calls
vb@130
   558
** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
vb@130
   559
** after reboot following a crash or power loss, the only bytes in a
vb@130
   560
** file that were written at the application level might have changed
vb@130
   561
** and that adjacent bytes, even bytes within the same sector are
vb@130
   562
** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
vb@130
   563
** flag indicate that a file cannot be deleted when open.  The
vb@130
   564
** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
vb@130
   565
** read-only media and cannot be changed even by processes with
vb@130
   566
** elevated privileges.
vb@130
   567
*/
vb@130
   568
#define SQLITE_IOCAP_ATOMIC                 0x00000001
vb@130
   569
#define SQLITE_IOCAP_ATOMIC512              0x00000002
vb@130
   570
#define SQLITE_IOCAP_ATOMIC1K               0x00000004
vb@130
   571
#define SQLITE_IOCAP_ATOMIC2K               0x00000008
vb@130
   572
#define SQLITE_IOCAP_ATOMIC4K               0x00000010
vb@130
   573
#define SQLITE_IOCAP_ATOMIC8K               0x00000020
vb@130
   574
#define SQLITE_IOCAP_ATOMIC16K              0x00000040
vb@130
   575
#define SQLITE_IOCAP_ATOMIC32K              0x00000080
vb@130
   576
#define SQLITE_IOCAP_ATOMIC64K              0x00000100
vb@130
   577
#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
vb@130
   578
#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
vb@130
   579
#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
vb@130
   580
#define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
vb@130
   581
#define SQLITE_IOCAP_IMMUTABLE              0x00002000
vb@130
   582
vb@130
   583
/*
vb@130
   584
** CAPI3REF: File Locking Levels
vb@130
   585
**
vb@130
   586
** SQLite uses one of these integer values as the second
vb@130
   587
** argument to calls it makes to the xLock() and xUnlock() methods
vb@130
   588
** of an [sqlite3_io_methods] object.
vb@130
   589
*/
vb@130
   590
#define SQLITE_LOCK_NONE          0
vb@130
   591
#define SQLITE_LOCK_SHARED        1
vb@130
   592
#define SQLITE_LOCK_RESERVED      2
vb@130
   593
#define SQLITE_LOCK_PENDING       3
vb@130
   594
#define SQLITE_LOCK_EXCLUSIVE     4
vb@130
   595
vb@130
   596
/*
vb@130
   597
** CAPI3REF: Synchronization Type Flags
vb@130
   598
**
vb@130
   599
** When SQLite invokes the xSync() method of an
vb@130
   600
** [sqlite3_io_methods] object it uses a combination of
vb@130
   601
** these integer values as the second argument.
vb@130
   602
**
vb@130
   603
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
vb@130
   604
** sync operation only needs to flush data to mass storage.  Inode
vb@130
   605
** information need not be flushed. If the lower four bits of the flag
vb@130
   606
** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
vb@130
   607
** If the lower four bits equal SQLITE_SYNC_FULL, that means
vb@130
   608
** to use Mac OS X style fullsync instead of fsync().
vb@130
   609
**
vb@130
   610
** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
vb@130
   611
** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
vb@130
   612
** settings.  The [synchronous pragma] determines when calls to the
vb@130
   613
** xSync VFS method occur and applies uniformly across all platforms.
vb@130
   614
** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
vb@130
   615
** energetic or rigorous or forceful the sync operations are and
vb@130
   616
** only make a difference on Mac OSX for the default SQLite code.
vb@130
   617
** (Third-party VFS implementations might also make the distinction
vb@130
   618
** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
vb@130
   619
** operating systems natively supported by SQLite, only Mac OSX
vb@130
   620
** cares about the difference.)
vb@130
   621
*/
vb@130
   622
#define SQLITE_SYNC_NORMAL        0x00002
vb@130
   623
#define SQLITE_SYNC_FULL          0x00003
vb@130
   624
#define SQLITE_SYNC_DATAONLY      0x00010
vb@130
   625
vb@130
   626
/*
vb@130
   627
** CAPI3REF: OS Interface Open File Handle
vb@130
   628
**
vb@130
   629
** An [sqlite3_file] object represents an open file in the 
vb@130
   630
** [sqlite3_vfs | OS interface layer].  Individual OS interface
vb@130
   631
** implementations will
vb@130
   632
** want to subclass this object by appending additional fields
vb@130
   633
** for their own use.  The pMethods entry is a pointer to an
vb@130
   634
** [sqlite3_io_methods] object that defines methods for performing
vb@130
   635
** I/O operations on the open file.
vb@130
   636
*/
vb@130
   637
typedef struct sqlite3_file sqlite3_file;
vb@130
   638
struct sqlite3_file {
vb@130
   639
  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
vb@130
   640
};
vb@130
   641
vb@130
   642
/*
vb@130
   643
** CAPI3REF: OS Interface File Virtual Methods Object
vb@130
   644
**
vb@130
   645
** Every file opened by the [sqlite3_vfs.xOpen] method populates an
vb@130
   646
** [sqlite3_file] object (or, more commonly, a subclass of the
vb@130
   647
** [sqlite3_file] object) with a pointer to an instance of this object.
vb@130
   648
** This object defines the methods used to perform various operations
vb@130
   649
** against the open file represented by the [sqlite3_file] object.
vb@130
   650
**
vb@130
   651
** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 
vb@130
   652
** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
vb@130
   653
** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
vb@130
   654
** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
vb@130
   655
** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
vb@130
   656
** to NULL.
vb@130
   657
**
vb@130
   658
** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
vb@130
   659
** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
vb@130
   660
** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
vb@130
   661
** flag may be ORed in to indicate that only the data of the file
vb@130
   662
** and not its inode needs to be synced.
vb@130
   663
**
vb@130
   664
** The integer values to xLock() and xUnlock() are one of
vb@130
   665
** <ul>
vb@130
   666
** <li> [SQLITE_LOCK_NONE],
vb@130
   667
** <li> [SQLITE_LOCK_SHARED],
vb@130
   668
** <li> [SQLITE_LOCK_RESERVED],
vb@130
   669
** <li> [SQLITE_LOCK_PENDING], or
vb@130
   670
** <li> [SQLITE_LOCK_EXCLUSIVE].
vb@130
   671
** </ul>
vb@130
   672
** xLock() increases the lock. xUnlock() decreases the lock.
vb@130
   673
** The xCheckReservedLock() method checks whether any database connection,
vb@130
   674
** either in this process or in some other process, is holding a RESERVED,
vb@130
   675
** PENDING, or EXCLUSIVE lock on the file.  It returns true
vb@130
   676
** if such a lock exists and false otherwise.
vb@130
   677
**
vb@130
   678
** The xFileControl() method is a generic interface that allows custom
vb@130
   679
** VFS implementations to directly control an open file using the
vb@130
   680
** [sqlite3_file_control()] interface.  The second "op" argument is an
vb@130
   681
** integer opcode.  The third argument is a generic pointer intended to
vb@130
   682
** point to a structure that may contain arguments or space in which to
vb@130
   683
** write return values.  Potential uses for xFileControl() might be
vb@130
   684
** functions to enable blocking locks with timeouts, to change the
vb@130
   685
** locking strategy (for example to use dot-file locks), to inquire
vb@130
   686
** about the status of a lock, or to break stale locks.  The SQLite
vb@130
   687
** core reserves all opcodes less than 100 for its own use.
vb@130
   688
** A [file control opcodes | list of opcodes] less than 100 is available.
vb@130
   689
** Applications that define a custom xFileControl method should use opcodes
vb@130
   690
** greater than 100 to avoid conflicts.  VFS implementations should
vb@130
   691
** return [SQLITE_NOTFOUND] for file control opcodes that they do not
vb@130
   692
** recognize.
vb@130
   693
**
vb@130
   694
** The xSectorSize() method returns the sector size of the
vb@130
   695
** device that underlies the file.  The sector size is the
vb@130
   696
** minimum write that can be performed without disturbing
vb@130
   697
** other bytes in the file.  The xDeviceCharacteristics()
vb@130
   698
** method returns a bit vector describing behaviors of the
vb@130
   699
** underlying device:
vb@130
   700
**
vb@130
   701
** <ul>
vb@130
   702
** <li> [SQLITE_IOCAP_ATOMIC]
vb@130
   703
** <li> [SQLITE_IOCAP_ATOMIC512]
vb@130
   704
** <li> [SQLITE_IOCAP_ATOMIC1K]
vb@130
   705
** <li> [SQLITE_IOCAP_ATOMIC2K]
vb@130
   706
** <li> [SQLITE_IOCAP_ATOMIC4K]
vb@130
   707
** <li> [SQLITE_IOCAP_ATOMIC8K]
vb@130
   708
** <li> [SQLITE_IOCAP_ATOMIC16K]
vb@130
   709
** <li> [SQLITE_IOCAP_ATOMIC32K]
vb@130
   710
** <li> [SQLITE_IOCAP_ATOMIC64K]
vb@130
   711
** <li> [SQLITE_IOCAP_SAFE_APPEND]
vb@130
   712
** <li> [SQLITE_IOCAP_SEQUENTIAL]
vb@130
   713
** </ul>
vb@130
   714
**
vb@130
   715
** The SQLITE_IOCAP_ATOMIC property means that all writes of
vb@130
   716
** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
vb@130
   717
** mean that writes of blocks that are nnn bytes in size and
vb@130
   718
** are aligned to an address which is an integer multiple of
vb@130
   719
** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
vb@130
   720
** that when data is appended to a file, the data is appended
vb@130
   721
** first then the size of the file is extended, never the other
vb@130
   722
** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
vb@130
   723
** information is written to disk in the same order as calls
vb@130
   724
** to xWrite().
vb@130
   725
**
vb@130
   726
** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
vb@130
   727
** in the unread portions of the buffer with zeros.  A VFS that
vb@130
   728
** fails to zero-fill short reads might seem to work.  However,
vb@130
   729
** failure to zero-fill short reads will eventually lead to
vb@130
   730
** database corruption.
vb@130
   731
*/
vb@130
   732
typedef struct sqlite3_io_methods sqlite3_io_methods;
vb@130
   733
struct sqlite3_io_methods {
vb@130
   734
  int iVersion;
vb@130
   735
  int (*xClose)(sqlite3_file*);
vb@130
   736
  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
vb@130
   737
  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
vb@130
   738
  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
vb@130
   739
  int (*xSync)(sqlite3_file*, int flags);
vb@130
   740
  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
vb@130
   741
  int (*xLock)(sqlite3_file*, int);
vb@130
   742
  int (*xUnlock)(sqlite3_file*, int);
vb@130
   743
  int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
vb@130
   744
  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
vb@130
   745
  int (*xSectorSize)(sqlite3_file*);
vb@130
   746
  int (*xDeviceCharacteristics)(sqlite3_file*);
vb@130
   747
  /* Methods above are valid for version 1 */
vb@130
   748
  int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
vb@130
   749
  int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
vb@130
   750
  void (*xShmBarrier)(sqlite3_file*);
vb@130
   751
  int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
vb@130
   752
  /* Methods above are valid for version 2 */
vb@130
   753
  int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
vb@130
   754
  int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
vb@130
   755
  /* Methods above are valid for version 3 */
vb@130
   756
  /* Additional methods may be added in future releases */
vb@130
   757
};
vb@130
   758
vb@130
   759
/*
vb@130
   760
** CAPI3REF: Standard File Control Opcodes
vb@130
   761
** KEYWORDS: {file control opcodes} {file control opcode}
vb@130
   762
**
vb@130
   763
** These integer constants are opcodes for the xFileControl method
vb@130
   764
** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
vb@130
   765
** interface.
vb@130
   766
**
Edouard@491
   767
** <ul>
Edouard@491
   768
** <li>[[SQLITE_FCNTL_LOCKSTATE]]
vb@130
   769
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
vb@130
   770
** opcode causes the xFileControl method to write the current state of
vb@130
   771
** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
vb@130
   772
** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
vb@130
   773
** into an integer that the pArg argument points to. This capability
Edouard@491
   774
** is used during testing and is only available when the SQLITE_TEST
Edouard@491
   775
** compile-time option is used.
Edouard@491
   776
**
vb@130
   777
** <li>[[SQLITE_FCNTL_SIZE_HINT]]
vb@130
   778
** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
vb@130
   779
** layer a hint of how large the database file will grow to be during the
vb@130
   780
** current transaction.  This hint is not guaranteed to be accurate but it
vb@130
   781
** is often close.  The underlying VFS might choose to preallocate database
vb@130
   782
** file space based on this hint in order to help writes to the database
vb@130
   783
** file run faster.
vb@130
   784
**
vb@130
   785
** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
vb@130
   786
** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
vb@130
   787
** extends and truncates the database file in chunks of a size specified
vb@130
   788
** by the user. The fourth argument to [sqlite3_file_control()] should 
vb@130
   789
** point to an integer (type int) containing the new chunk-size to use
vb@130
   790
** for the nominated database. Allocating database file space in large
vb@130
   791
** chunks (say 1MB at a time), may reduce file-system fragmentation and
vb@130
   792
** improve performance on some systems.
vb@130
   793
**
vb@130
   794
** <li>[[SQLITE_FCNTL_FILE_POINTER]]
vb@130
   795
** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
vb@130
   796
** to the [sqlite3_file] object associated with a particular database
Edouard@491
   797
** connection.  See also [SQLITE_FCNTL_JOURNAL_POINTER].
Edouard@491
   798
**
Edouard@491
   799
** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
Edouard@491
   800
** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
Edouard@491
   801
** to the [sqlite3_file] object associated with the journal file (either
Edouard@491
   802
** the [rollback journal] or the [write-ahead log]) for a particular database
Edouard@491
   803
** connection.  See also [SQLITE_FCNTL_FILE_POINTER].
vb@130
   804
**
vb@130
   805
** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
vb@130
   806
** No longer in use.
vb@130
   807
**
vb@130
   808
** <li>[[SQLITE_FCNTL_SYNC]]
vb@130
   809
** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
vb@130
   810
** sent to the VFS immediately before the xSync method is invoked on a
vb@130
   811
** database file descriptor. Or, if the xSync method is not invoked 
vb@130
   812
** because the user has configured SQLite with 
vb@130
   813
** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 
vb@130
   814
** of the xSync method. In most cases, the pointer argument passed with
vb@130
   815
** this file-control is NULL. However, if the database file is being synced
vb@130
   816
** as part of a multi-database commit, the argument points to a nul-terminated
vb@130
   817
** string containing the transactions master-journal file name. VFSes that 
vb@130
   818
** do not need this signal should silently ignore this opcode. Applications 
vb@130
   819
** should not call [sqlite3_file_control()] with this opcode as doing so may 
vb@130
   820
** disrupt the operation of the specialized VFSes that do require it.  
vb@130
   821
**
vb@130
   822
** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
vb@130
   823
** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
vb@130
   824
** and sent to the VFS after a transaction has been committed immediately
vb@130
   825
** but before the database is unlocked. VFSes that do not need this signal
vb@130
   826
** should silently ignore this opcode. Applications should not call
vb@130
   827
** [sqlite3_file_control()] with this opcode as doing so may disrupt the 
vb@130
   828
** operation of the specialized VFSes that do require it.  
vb@130
   829
**
vb@130
   830
** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
vb@130
   831
** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
vb@130
   832
** retry counts and intervals for certain disk I/O operations for the
vb@130
   833
** windows [VFS] in order to provide robustness in the presence of
vb@130
   834
** anti-virus programs.  By default, the windows VFS will retry file read,
vb@130
   835
** file write, and file delete operations up to 10 times, with a delay
vb@130
   836
** of 25 milliseconds before the first retry and with the delay increasing
vb@130
   837
** by an additional 25 milliseconds with each subsequent retry.  This
vb@130
   838
** opcode allows these two values (10 retries and 25 milliseconds of delay)
vb@130
   839
** to be adjusted.  The values are changed for all database connections
vb@130
   840
** within the same process.  The argument is a pointer to an array of two
vb@130
   841
** integers where the first integer i the new retry count and the second
vb@130
   842
** integer is the delay.  If either integer is negative, then the setting
vb@130
   843
** is not changed but instead the prior value of that setting is written
vb@130
   844
** into the array entry, allowing the current retry settings to be
vb@130
   845
** interrogated.  The zDbName parameter is ignored.
vb@130
   846
**
vb@130
   847
** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
vb@130
   848
** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
vb@130
   849
** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
vb@130
   850
** write ahead log and shared memory files used for transaction control
vb@130
   851
** are automatically deleted when the latest connection to the database
vb@130
   852
** closes.  Setting persistent WAL mode causes those files to persist after
vb@130
   853
** close.  Persisting the files is useful when other processes that do not
vb@130
   854
** have write permission on the directory containing the database file want
vb@130
   855
** to read the database file, as the WAL and shared memory files must exist
vb@130
   856
** in order for the database to be readable.  The fourth parameter to
vb@130
   857
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
vb@130
   858
** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
vb@130
   859
** WAL mode.  If the integer is -1, then it is overwritten with the current
vb@130
   860
** WAL persistence setting.
vb@130
   861
**
vb@130
   862
** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
vb@130
   863
** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
vb@130
   864
** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
vb@130
   865
** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
vb@130
   866
** xDeviceCharacteristics methods. The fourth parameter to
vb@130
   867
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
vb@130
   868
** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
vb@130
   869
** mode.  If the integer is -1, then it is overwritten with the current
vb@130
   870
** zero-damage mode setting.
vb@130
   871
**
vb@130
   872
** <li>[[SQLITE_FCNTL_OVERWRITE]]
vb@130
   873
** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
vb@130
   874
** a write transaction to indicate that, unless it is rolled back for some
vb@130
   875
** reason, the entire database file will be overwritten by the current 
vb@130
   876
** transaction. This is used by VACUUM operations.
vb@130
   877
**
vb@130
   878
** <li>[[SQLITE_FCNTL_VFSNAME]]
vb@130
   879
** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
vb@130
   880
** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
vb@130
   881
** final bottom-level VFS are written into memory obtained from 
vb@130
   882
** [sqlite3_malloc()] and the result is stored in the char* variable
vb@130
   883
** that the fourth parameter of [sqlite3_file_control()] points to.
vb@130
   884
** The caller is responsible for freeing the memory when done.  As with
vb@130
   885
** all file-control actions, there is no guarantee that this will actually
vb@130
   886
** do anything.  Callers should initialize the char* variable to a NULL
vb@130
   887
** pointer in case this file-control is not implemented.  This file-control
vb@130
   888
** is intended for diagnostic use only.
vb@130
   889
**
Edouard@491
   890
** <li>[[SQLITE_FCNTL_VFS_POINTER]]
Edouard@491
   891
** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
Edouard@491
   892
** [VFSes] currently in use.  ^(The argument X in
Edouard@491
   893
** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
Edouard@491
   894
** of type "[sqlite3_vfs] **".  This opcodes will set *X
Edouard@491
   895
** to a pointer to the top-level VFS.)^
Edouard@491
   896
** ^When there are multiple VFS shims in the stack, this opcode finds the
Edouard@491
   897
** upper-most shim only.
Edouard@491
   898
**
vb@130
   899
** <li>[[SQLITE_FCNTL_PRAGMA]]
vb@130
   900
** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 
vb@130
   901
** file control is sent to the open [sqlite3_file] object corresponding
vb@130
   902
** to the database file to which the pragma statement refers. ^The argument
vb@130
   903
** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
vb@130
   904
** pointers to strings (char**) in which the second element of the array
vb@130
   905
** is the name of the pragma and the third element is the argument to the
vb@130
   906
** pragma or NULL if the pragma has no argument.  ^The handler for an
vb@130
   907
** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
vb@130
   908
** of the char** argument point to a string obtained from [sqlite3_mprintf()]
vb@130
   909
** or the equivalent and that string will become the result of the pragma or
vb@130
   910
** the error message if the pragma fails. ^If the
vb@130
   911
** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 
vb@130
   912
** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
vb@130
   913
** file control returns [SQLITE_OK], then the parser assumes that the
vb@130
   914
** VFS has handled the PRAGMA itself and the parser generates a no-op
Edouard@491
   915
** prepared statement if result string is NULL, or that returns a copy
Edouard@491
   916
** of the result string if the string is non-NULL.
Edouard@491
   917
** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
vb@130
   918
** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
vb@130
   919
** that the VFS encountered an error while handling the [PRAGMA] and the
vb@130
   920
** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
vb@130
   921
** file control occurs at the beginning of pragma statement analysis and so
vb@130
   922
** it is able to override built-in [PRAGMA] statements.
vb@130
   923
**
vb@130
   924
** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
vb@130
   925
** ^The [SQLITE_FCNTL_BUSYHANDLER]
vb@130
   926
** file-control may be invoked by SQLite on the database file handle
vb@130
   927
** shortly after it is opened in order to provide a custom VFS with access
vb@130
   928
** to the connections busy-handler callback. The argument is of type (void **)
vb@130
   929
** - an array of two (void *) values. The first (void *) actually points
vb@130
   930
** to a function of type (int (*)(void *)). In order to invoke the connections
vb@130
   931
** busy-handler, this function should be invoked with the second (void *) in
vb@130
   932
** the array as the only argument. If it returns non-zero, then the operation
vb@130
   933
** should be retried. If it returns zero, the custom VFS should abandon the
vb@130
   934
** current operation.
vb@130
   935
**
vb@130
   936
** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
vb@130
   937
** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
vb@130
   938
** to have SQLite generate a
vb@130
   939
** temporary filename using the same algorithm that is followed to generate
vb@130
   940
** temporary filenames for TEMP tables and other internal uses.  The
vb@130
   941
** argument should be a char** which will be filled with the filename
vb@130
   942
** written into memory obtained from [sqlite3_malloc()].  The caller should
vb@130
   943
** invoke [sqlite3_free()] on the result to avoid a memory leak.
vb@130
   944
**
vb@130
   945
** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
vb@130
   946
** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
vb@130
   947
** maximum number of bytes that will be used for memory-mapped I/O.
vb@130
   948
** The argument is a pointer to a value of type sqlite3_int64 that
vb@130
   949
** is an advisory maximum number of bytes in the file to memory map.  The
vb@130
   950
** pointer is overwritten with the old value.  The limit is not changed if
vb@130
   951
** the value originally pointed to is negative, and so the current limit 
vb@130
   952
** can be queried by passing in a pointer to a negative number.  This
vb@130
   953
** file-control is used internally to implement [PRAGMA mmap_size].
vb@130
   954
**
vb@130
   955
** <li>[[SQLITE_FCNTL_TRACE]]
vb@130
   956
** The [SQLITE_FCNTL_TRACE] file control provides advisory information
vb@130
   957
** to the VFS about what the higher layers of the SQLite stack are doing.
vb@130
   958
** This file control is used by some VFS activity tracing [shims].
vb@130
   959
** The argument is a zero-terminated string.  Higher layers in the
vb@130
   960
** SQLite stack may generate instances of this file control if
vb@130
   961
** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
vb@130
   962
**
vb@130
   963
** <li>[[SQLITE_FCNTL_HAS_MOVED]]
vb@130
   964
** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
vb@130
   965
** pointer to an integer and it writes a boolean into that integer depending
vb@130
   966
** on whether or not the file has been renamed, moved, or deleted since it
vb@130
   967
** was first opened.
vb@130
   968
**
vb@130
   969
** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
vb@130
   970
** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
vb@130
   971
** opcode causes the xFileControl method to swap the file handle with the one
vb@130
   972
** pointed to by the pArg argument.  This capability is used during testing
vb@130
   973
** and only needs to be supported when SQLITE_TEST is defined.
vb@130
   974
**
Edouard@491
   975
** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
Edouard@491
   976
** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
Edouard@491
   977
** be advantageous to block on the next WAL lock if the lock is not immediately
Edouard@491
   978
** available.  The WAL subsystem issues this signal during rare
Edouard@491
   979
** circumstances in order to fix a problem with priority inversion.
Edouard@491
   980
** Applications should <em>not</em> use this file-control.
Edouard@491
   981
**
Edouard@491
   982
** <li>[[SQLITE_FCNTL_ZIPVFS]]
Edouard@491
   983
** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
Edouard@491
   984
** VFS should return SQLITE_NOTFOUND for this opcode.
Edouard@491
   985
**
Edouard@491
   986
** <li>[[SQLITE_FCNTL_RBU]]
Edouard@491
   987
** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
Edouard@491
   988
** the RBU extension only.  All other VFS should return SQLITE_NOTFOUND for
Edouard@491
   989
** this opcode.  
vb@130
   990
** </ul>
vb@130
   991
*/
vb@130
   992
#define SQLITE_FCNTL_LOCKSTATE               1
Edouard@491
   993
#define SQLITE_FCNTL_GET_LOCKPROXYFILE       2
Edouard@491
   994
#define SQLITE_FCNTL_SET_LOCKPROXYFILE       3
Edouard@491
   995
#define SQLITE_FCNTL_LAST_ERRNO              4
vb@130
   996
#define SQLITE_FCNTL_SIZE_HINT               5
vb@130
   997
#define SQLITE_FCNTL_CHUNK_SIZE              6
vb@130
   998
#define SQLITE_FCNTL_FILE_POINTER            7
vb@130
   999
#define SQLITE_FCNTL_SYNC_OMITTED            8
vb@130
  1000
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
vb@130
  1001
#define SQLITE_FCNTL_PERSIST_WAL            10
vb@130
  1002
#define SQLITE_FCNTL_OVERWRITE              11
vb@130
  1003
#define SQLITE_FCNTL_VFSNAME                12
vb@130
  1004
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
vb@130
  1005
#define SQLITE_FCNTL_PRAGMA                 14
vb@130
  1006
#define SQLITE_FCNTL_BUSYHANDLER            15
vb@130
  1007
#define SQLITE_FCNTL_TEMPFILENAME           16
vb@130
  1008
#define SQLITE_FCNTL_MMAP_SIZE              18
vb@130
  1009
#define SQLITE_FCNTL_TRACE                  19
vb@130
  1010
#define SQLITE_FCNTL_HAS_MOVED              20
vb@130
  1011
#define SQLITE_FCNTL_SYNC                   21
vb@130
  1012
#define SQLITE_FCNTL_COMMIT_PHASETWO        22
vb@130
  1013
#define SQLITE_FCNTL_WIN32_SET_HANDLE       23
Edouard@491
  1014
#define SQLITE_FCNTL_WAL_BLOCK              24
Edouard@491
  1015
#define SQLITE_FCNTL_ZIPVFS                 25
Edouard@491
  1016
#define SQLITE_FCNTL_RBU                    26
Edouard@491
  1017
#define SQLITE_FCNTL_VFS_POINTER            27
Edouard@491
  1018
#define SQLITE_FCNTL_JOURNAL_POINTER        28
Edouard@491
  1019
Edouard@491
  1020
/* deprecated names */
Edouard@491
  1021
#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
Edouard@491
  1022
#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
Edouard@491
  1023
#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO
Edouard@491
  1024
vb@130
  1025
vb@130
  1026
/*
vb@130
  1027
** CAPI3REF: Mutex Handle
vb@130
  1028
**
vb@130
  1029
** The mutex module within SQLite defines [sqlite3_mutex] to be an
vb@130
  1030
** abstract type for a mutex object.  The SQLite core never looks
vb@130
  1031
** at the internal representation of an [sqlite3_mutex].  It only
vb@130
  1032
** deals with pointers to the [sqlite3_mutex] object.
vb@130
  1033
**
vb@130
  1034
** Mutexes are created using [sqlite3_mutex_alloc()].
vb@130
  1035
*/
vb@130
  1036
typedef struct sqlite3_mutex sqlite3_mutex;
vb@130
  1037
vb@130
  1038
/*
vb@130
  1039
** CAPI3REF: OS Interface Object
vb@130
  1040
**
vb@130
  1041
** An instance of the sqlite3_vfs object defines the interface between
vb@130
  1042
** the SQLite core and the underlying operating system.  The "vfs"
vb@130
  1043
** in the name of the object stands for "virtual file system".  See
vb@130
  1044
** the [VFS | VFS documentation] for further information.
vb@130
  1045
**
vb@130
  1046
** The value of the iVersion field is initially 1 but may be larger in
vb@130
  1047
** future versions of SQLite.  Additional fields may be appended to this
vb@130
  1048
** object when the iVersion value is increased.  Note that the structure
vb@130
  1049
** of the sqlite3_vfs object changes in the transaction between
vb@130
  1050
** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
vb@130
  1051
** modified.
vb@130
  1052
**
vb@130
  1053
** The szOsFile field is the size of the subclassed [sqlite3_file]
vb@130
  1054
** structure used by this VFS.  mxPathname is the maximum length of
vb@130
  1055
** a pathname in this VFS.
vb@130
  1056
**
vb@130
  1057
** Registered sqlite3_vfs objects are kept on a linked list formed by
vb@130
  1058
** the pNext pointer.  The [sqlite3_vfs_register()]
vb@130
  1059
** and [sqlite3_vfs_unregister()] interfaces manage this list
vb@130
  1060
** in a thread-safe way.  The [sqlite3_vfs_find()] interface
vb@130
  1061
** searches the list.  Neither the application code nor the VFS
vb@130
  1062
** implementation should use the pNext pointer.
vb@130
  1063
**
vb@130
  1064
** The pNext field is the only field in the sqlite3_vfs
vb@130
  1065
** structure that SQLite will ever modify.  SQLite will only access
vb@130
  1066
** or modify this field while holding a particular static mutex.
vb@130
  1067
** The application should never modify anything within the sqlite3_vfs
vb@130
  1068
** object once the object has been registered.
vb@130
  1069
**
vb@130
  1070
** The zName field holds the name of the VFS module.  The name must
vb@130
  1071
** be unique across all VFS modules.
vb@130
  1072
**
vb@130
  1073
** [[sqlite3_vfs.xOpen]]
vb@130
  1074
** ^SQLite guarantees that the zFilename parameter to xOpen
vb@130
  1075
** is either a NULL pointer or string obtained
vb@130
  1076
** from xFullPathname() with an optional suffix added.
vb@130
  1077
** ^If a suffix is added to the zFilename parameter, it will
vb@130
  1078
** consist of a single "-" character followed by no more than
vb@130
  1079
** 11 alphanumeric and/or "-" characters.
vb@130
  1080
** ^SQLite further guarantees that
vb@130
  1081
** the string will be valid and unchanged until xClose() is
vb@130
  1082
** called. Because of the previous sentence,
vb@130
  1083
** the [sqlite3_file] can safely store a pointer to the
vb@130
  1084
** filename if it needs to remember the filename for some reason.
vb@130
  1085
** If the zFilename parameter to xOpen is a NULL pointer then xOpen
vb@130
  1086
** must invent its own temporary name for the file.  ^Whenever the 
vb@130
  1087
** xFilename parameter is NULL it will also be the case that the
vb@130
  1088
** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
vb@130
  1089
**
vb@130
  1090
** The flags argument to xOpen() includes all bits set in
vb@130
  1091
** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
vb@130
  1092
** or [sqlite3_open16()] is used, then flags includes at least
vb@130
  1093
** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 
vb@130
  1094
** If xOpen() opens a file read-only then it sets *pOutFlags to
vb@130
  1095
** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
vb@130
  1096
**
vb@130
  1097
** ^(SQLite will also add one of the following flags to the xOpen()
vb@130
  1098
** call, depending on the object being opened:
vb@130
  1099
**
vb@130
  1100
** <ul>
vb@130
  1101
** <li>  [SQLITE_OPEN_MAIN_DB]
vb@130
  1102
** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
vb@130
  1103
** <li>  [SQLITE_OPEN_TEMP_DB]
vb@130
  1104
** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
vb@130
  1105
** <li>  [SQLITE_OPEN_TRANSIENT_DB]
vb@130
  1106
** <li>  [SQLITE_OPEN_SUBJOURNAL]
vb@130
  1107
** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
vb@130
  1108
** <li>  [SQLITE_OPEN_WAL]
vb@130
  1109
** </ul>)^
vb@130
  1110
**
vb@130
  1111
** The file I/O implementation can use the object type flags to
vb@130
  1112
** change the way it deals with files.  For example, an application
vb@130
  1113
** that does not care about crash recovery or rollback might make
vb@130
  1114
** the open of a journal file a no-op.  Writes to this journal would
vb@130
  1115
** also be no-ops, and any attempt to read the journal would return
vb@130
  1116
** SQLITE_IOERR.  Or the implementation might recognize that a database
vb@130
  1117
** file will be doing page-aligned sector reads and writes in a random
vb@130
  1118
** order and set up its I/O subsystem accordingly.
vb@130
  1119
**
vb@130
  1120
** SQLite might also add one of the following flags to the xOpen method:
vb@130
  1121
**
vb@130
  1122
** <ul>
vb@130
  1123
** <li> [SQLITE_OPEN_DELETEONCLOSE]
vb@130
  1124
** <li> [SQLITE_OPEN_EXCLUSIVE]
vb@130
  1125
** </ul>
vb@130
  1126
**
vb@130
  1127
** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
vb@130
  1128
** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
vb@130
  1129
** will be set for TEMP databases and their journals, transient
vb@130
  1130
** databases, and subjournals.
vb@130
  1131
**
vb@130
  1132
** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
vb@130
  1133
** with the [SQLITE_OPEN_CREATE] flag, which are both directly
vb@130
  1134
** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
vb@130
  1135
** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 
vb@130
  1136
** SQLITE_OPEN_CREATE, is used to indicate that file should always
vb@130
  1137
** be created, and that it is an error if it already exists.
vb@130
  1138
** It is <i>not</i> used to indicate the file should be opened 
vb@130
  1139
** for exclusive access.
vb@130
  1140
**
vb@130
  1141
** ^At least szOsFile bytes of memory are allocated by SQLite
vb@130
  1142
** to hold the  [sqlite3_file] structure passed as the third
vb@130
  1143
** argument to xOpen.  The xOpen method does not have to
vb@130
  1144
** allocate the structure; it should just fill it in.  Note that
vb@130
  1145
** the xOpen method must set the sqlite3_file.pMethods to either
vb@130
  1146
** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
vb@130
  1147
** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
vb@130
  1148
** element will be valid after xOpen returns regardless of the success
vb@130
  1149
** or failure of the xOpen call.
vb@130
  1150
**
vb@130
  1151
** [[sqlite3_vfs.xAccess]]
vb@130
  1152
** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
vb@130
  1153
** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
vb@130
  1154
** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
vb@130
  1155
** to test whether a file is at least readable.   The file can be a
vb@130
  1156
** directory.
vb@130
  1157
**
vb@130
  1158
** ^SQLite will always allocate at least mxPathname+1 bytes for the
vb@130
  1159
** output buffer xFullPathname.  The exact size of the output buffer
vb@130
  1160
** is also passed as a parameter to both  methods. If the output buffer
vb@130
  1161
** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
vb@130
  1162
** handled as a fatal error by SQLite, vfs implementations should endeavor
vb@130
  1163
** to prevent this by setting mxPathname to a sufficiently large value.
vb@130
  1164
**
vb@130
  1165
** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
vb@130
  1166
** interfaces are not strictly a part of the filesystem, but they are
vb@130
  1167
** included in the VFS structure for completeness.
vb@130
  1168
** The xRandomness() function attempts to return nBytes bytes
vb@130
  1169
** of good-quality randomness into zOut.  The return value is
vb@130
  1170
** the actual number of bytes of randomness obtained.
vb@130
  1171
** The xSleep() method causes the calling thread to sleep for at
vb@130
  1172
** least the number of microseconds given.  ^The xCurrentTime()
vb@130
  1173
** method returns a Julian Day Number for the current date and time as
vb@130
  1174
** a floating point value.
vb@130
  1175
** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
vb@130
  1176
** Day Number multiplied by 86400000 (the number of milliseconds in 
vb@130
  1177
** a 24-hour day).  
vb@130
  1178
** ^SQLite will use the xCurrentTimeInt64() method to get the current
vb@130
  1179
** date and time if that method is available (if iVersion is 2 or 
vb@130
  1180
** greater and the function pointer is not NULL) and will fall back
vb@130
  1181
** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
vb@130
  1182
**
vb@130
  1183
** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
vb@130
  1184
** are not used by the SQLite core.  These optional interfaces are provided
vb@130
  1185
** by some VFSes to facilitate testing of the VFS code. By overriding 
vb@130
  1186
** system calls with functions under its control, a test program can
vb@130
  1187
** simulate faults and error conditions that would otherwise be difficult
vb@130
  1188
** or impossible to induce.  The set of system calls that can be overridden
vb@130
  1189
** varies from one VFS to another, and from one version of the same VFS to the
vb@130
  1190
** next.  Applications that use these interfaces must be prepared for any
vb@130
  1191
** or all of these interfaces to be NULL or for their behavior to change
vb@130
  1192
** from one release to the next.  Applications must not attempt to access
vb@130
  1193
** any of these methods if the iVersion of the VFS is less than 3.
vb@130
  1194
*/
vb@130
  1195
typedef struct sqlite3_vfs sqlite3_vfs;
vb@130
  1196
typedef void (*sqlite3_syscall_ptr)(void);
vb@130
  1197
struct sqlite3_vfs {
vb@130
  1198
  int iVersion;            /* Structure version number (currently 3) */
vb@130
  1199
  int szOsFile;            /* Size of subclassed sqlite3_file */
vb@130
  1200
  int mxPathname;          /* Maximum file pathname length */
vb@130
  1201
  sqlite3_vfs *pNext;      /* Next registered VFS */
vb@130
  1202
  const char *zName;       /* Name of this virtual file system */
vb@130
  1203
  void *pAppData;          /* Pointer to application-specific data */
vb@130
  1204
  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
vb@130
  1205
               int flags, int *pOutFlags);
vb@130
  1206
  int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
vb@130
  1207
  int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
vb@130
  1208
  int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
vb@130
  1209
  void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
vb@130
  1210
  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
vb@130
  1211
  void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
vb@130
  1212
  void (*xDlClose)(sqlite3_vfs*, void*);
vb@130
  1213
  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
vb@130
  1214
  int (*xSleep)(sqlite3_vfs*, int microseconds);
vb@130
  1215
  int (*xCurrentTime)(sqlite3_vfs*, double*);
vb@130
  1216
  int (*xGetLastError)(sqlite3_vfs*, int, char *);
vb@130
  1217
  /*
vb@130
  1218
  ** The methods above are in version 1 of the sqlite_vfs object
vb@130
  1219
  ** definition.  Those that follow are added in version 2 or later
vb@130
  1220
  */
vb@130
  1221
  int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
vb@130
  1222
  /*
vb@130
  1223
  ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
vb@130
  1224
  ** Those below are for version 3 and greater.
vb@130
  1225
  */
vb@130
  1226
  int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
vb@130
  1227
  sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
vb@130
  1228
  const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
vb@130
  1229
  /*
vb@130
  1230
  ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
vb@716
  1231
  ** New fields may be appended in future versions.  The iVersion
vb@130
  1232
  ** value will increment whenever this happens. 
vb@130
  1233
  */
vb@130
  1234
};
vb@130
  1235
vb@130
  1236
/*
vb@130
  1237
** CAPI3REF: Flags for the xAccess VFS method
vb@130
  1238
**
vb@130
  1239
** These integer constants can be used as the third parameter to
vb@130
  1240
** the xAccess method of an [sqlite3_vfs] object.  They determine
vb@130
  1241
** what kind of permissions the xAccess method is looking for.
vb@130
  1242
** With SQLITE_ACCESS_EXISTS, the xAccess method
vb@130
  1243
** simply checks whether the file exists.
vb@130
  1244
** With SQLITE_ACCESS_READWRITE, the xAccess method
vb@130
  1245
** checks whether the named directory is both readable and writable
vb@130
  1246
** (in other words, if files can be added, removed, and renamed within
vb@130
  1247
** the directory).
vb@130
  1248
** The SQLITE_ACCESS_READWRITE constant is currently used only by the
vb@130
  1249
** [temp_store_directory pragma], though this could change in a future
vb@130
  1250
** release of SQLite.
vb@130
  1251
** With SQLITE_ACCESS_READ, the xAccess method
vb@130
  1252
** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
vb@130
  1253
** currently unused, though it might be used in a future release of
vb@130
  1254
** SQLite.
vb@130
  1255
*/
vb@130
  1256
#define SQLITE_ACCESS_EXISTS    0
vb@130
  1257
#define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
vb@130
  1258
#define SQLITE_ACCESS_READ      2   /* Unused */
vb@130
  1259
vb@130
  1260
/*
vb@130
  1261
** CAPI3REF: Flags for the xShmLock VFS method
vb@130
  1262
**
vb@130
  1263
** These integer constants define the various locking operations
vb@130
  1264
** allowed by the xShmLock method of [sqlite3_io_methods].  The
vb@130
  1265
** following are the only legal combinations of flags to the
vb@130
  1266
** xShmLock method:
vb@130
  1267
**
vb@130
  1268
** <ul>
vb@130
  1269
** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
vb@130
  1270
** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
vb@130
  1271
** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
vb@130
  1272
** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
vb@130
  1273
** </ul>
vb@130
  1274
**
vb@130
  1275
** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
Edouard@491
  1276
** was given on the corresponding lock.  
vb@130
  1277
**
vb@130
  1278
** The xShmLock method can transition between unlocked and SHARED or
vb@130
  1279
** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
vb@130
  1280
** and EXCLUSIVE.
vb@130
  1281
*/
vb@130
  1282
#define SQLITE_SHM_UNLOCK       1
vb@130
  1283
#define SQLITE_SHM_LOCK         2
vb@130
  1284
#define SQLITE_SHM_SHARED       4
vb@130
  1285
#define SQLITE_SHM_EXCLUSIVE    8
vb@130
  1286
vb@130
  1287
/*
vb@130
  1288
** CAPI3REF: Maximum xShmLock index
vb@130
  1289
**
vb@130
  1290
** The xShmLock method on [sqlite3_io_methods] may use values
vb@130
  1291
** between 0 and this upper bound as its "offset" argument.
vb@130
  1292
** The SQLite core will never attempt to acquire or release a
vb@130
  1293
** lock outside of this range
vb@130
  1294
*/
vb@130
  1295
#define SQLITE_SHM_NLOCK        8
vb@130
  1296
vb@130
  1297
vb@130
  1298
/*
vb@130
  1299
** CAPI3REF: Initialize The SQLite Library
vb@130
  1300
**
vb@130
  1301
** ^The sqlite3_initialize() routine initializes the
vb@130
  1302
** SQLite library.  ^The sqlite3_shutdown() routine
vb@130
  1303
** deallocates any resources that were allocated by sqlite3_initialize().
vb@130
  1304
** These routines are designed to aid in process initialization and
vb@130
  1305
** shutdown on embedded systems.  Workstation applications using
vb@130
  1306
** SQLite normally do not need to invoke either of these routines.
vb@130
  1307
**
vb@130
  1308
** A call to sqlite3_initialize() is an "effective" call if it is
vb@130
  1309
** the first time sqlite3_initialize() is invoked during the lifetime of
vb@130
  1310
** the process, or if it is the first time sqlite3_initialize() is invoked
vb@130
  1311
** following a call to sqlite3_shutdown().  ^(Only an effective call
vb@130
  1312
** of sqlite3_initialize() does any initialization.  All other calls
vb@130
  1313
** are harmless no-ops.)^
vb@130
  1314
**
vb@130
  1315
** A call to sqlite3_shutdown() is an "effective" call if it is the first
vb@130
  1316
** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
vb@130
  1317
** an effective call to sqlite3_shutdown() does any deinitialization.
vb@130
  1318
** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
vb@130
  1319
**
vb@130
  1320
** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
vb@130
  1321
** is not.  The sqlite3_shutdown() interface must only be called from a
vb@130
  1322
** single thread.  All open [database connections] must be closed and all
vb@130
  1323
** other SQLite resources must be deallocated prior to invoking
vb@130
  1324
** sqlite3_shutdown().
vb@130
  1325
**
vb@130
  1326
** Among other things, ^sqlite3_initialize() will invoke
vb@130
  1327
** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
vb@130
  1328
** will invoke sqlite3_os_end().
vb@130
  1329
**
vb@130
  1330
** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
vb@130
  1331
** ^If for some reason, sqlite3_initialize() is unable to initialize
vb@130
  1332
** the library (perhaps it is unable to allocate a needed resource such
vb@130
  1333
** as a mutex) it returns an [error code] other than [SQLITE_OK].
vb@130
  1334
**
vb@130
  1335
** ^The sqlite3_initialize() routine is called internally by many other
vb@130
  1336
** SQLite interfaces so that an application usually does not need to
vb@130
  1337
** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
vb@130
  1338
** calls sqlite3_initialize() so the SQLite library will be automatically
vb@130
  1339
** initialized when [sqlite3_open()] is called if it has not be initialized
vb@130
  1340
** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
vb@130
  1341
** compile-time option, then the automatic calls to sqlite3_initialize()
vb@130
  1342
** are omitted and the application must call sqlite3_initialize() directly
vb@130
  1343
** prior to using any other SQLite interface.  For maximum portability,
vb@130
  1344
** it is recommended that applications always invoke sqlite3_initialize()
vb@130
  1345
** directly prior to using any other SQLite interface.  Future releases
vb@130
  1346
** of SQLite may require this.  In other words, the behavior exhibited
vb@130
  1347
** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
vb@130
  1348
** default behavior in some future release of SQLite.
vb@130
  1349
**
vb@130
  1350
** The sqlite3_os_init() routine does operating-system specific
vb@130
  1351
** initialization of the SQLite library.  The sqlite3_os_end()
vb@130
  1352
** routine undoes the effect of sqlite3_os_init().  Typical tasks
vb@130
  1353
** performed by these routines include allocation or deallocation
vb@130
  1354
** of static resources, initialization of global variables,
vb@130
  1355
** setting up a default [sqlite3_vfs] module, or setting up
vb@130
  1356
** a default configuration using [sqlite3_config()].
vb@130
  1357
**
vb@130
  1358
** The application should never invoke either sqlite3_os_init()
vb@130
  1359
** or sqlite3_os_end() directly.  The application should only invoke
vb@130
  1360
** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
vb@130
  1361
** interface is called automatically by sqlite3_initialize() and
vb@130
  1362
** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
vb@130
  1363
** implementations for sqlite3_os_init() and sqlite3_os_end()
vb@130
  1364
** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
vb@130
  1365
** When [custom builds | built for other platforms]
vb@130
  1366
** (using the [SQLITE_OS_OTHER=1] compile-time
vb@130
  1367
** option) the application must supply a suitable implementation for
vb@130
  1368
** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
vb@130
  1369
** implementation of sqlite3_os_init() or sqlite3_os_end()
vb@130
  1370
** must return [SQLITE_OK] on success and some other [error code] upon
vb@130
  1371
** failure.
vb@130
  1372
*/
Edouard@491
  1373
SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void);
Edouard@491
  1374
SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void);
Edouard@491
  1375
SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void);
Edouard@491
  1376
SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void);
vb@130
  1377
vb@130
  1378
/*
vb@130
  1379
** CAPI3REF: Configuring The SQLite Library
vb@130
  1380
**
vb@130
  1381
** The sqlite3_config() interface is used to make global configuration
vb@130
  1382
** changes to SQLite in order to tune SQLite to the specific needs of
vb@130
  1383
** the application.  The default configuration is recommended for most
vb@130
  1384
** applications and so this routine is usually not necessary.  It is
vb@130
  1385
** provided to support rare applications with unusual needs.
vb@130
  1386
**
Edouard@491
  1387
** <b>The sqlite3_config() interface is not threadsafe. The application
Edouard@491
  1388
** must ensure that no other SQLite interfaces are invoked by other
Edouard@491
  1389
** threads while sqlite3_config() is running.</b>
Edouard@491
  1390
**
Edouard@491
  1391
** The sqlite3_config() interface
vb@130
  1392
** may only be invoked prior to library initialization using
vb@130
  1393
** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
vb@130
  1394
** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
vb@130
  1395
** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
vb@130
  1396
** Note, however, that ^sqlite3_config() can be called as part of the
vb@130
  1397
** implementation of an application-defined [sqlite3_os_init()].
vb@130
  1398
**
vb@130
  1399
** The first argument to sqlite3_config() is an integer
vb@130
  1400
** [configuration option] that determines
vb@130
  1401
** what property of SQLite is to be configured.  Subsequent arguments
vb@130
  1402
** vary depending on the [configuration option]
vb@130
  1403
** in the first argument.
vb@130
  1404
**
vb@130
  1405
** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
vb@130
  1406
** ^If the option is unknown or SQLite is unable to set the option
vb@130
  1407
** then this routine returns a non-zero [error code].
vb@130
  1408
*/
Edouard@491
  1409
SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...);
vb@130
  1410
vb@130
  1411
/*
vb@130
  1412
** CAPI3REF: Configure database connections
Edouard@491
  1413
** METHOD: sqlite3
vb@130
  1414
**
vb@130
  1415
** The sqlite3_db_config() interface is used to make configuration
vb@130
  1416
** changes to a [database connection].  The interface is similar to
vb@130
  1417
** [sqlite3_config()] except that the changes apply to a single
vb@130
  1418
** [database connection] (specified in the first argument).
vb@130
  1419
**
vb@130
  1420
** The second argument to sqlite3_db_config(D,V,...)  is the
vb@130
  1421
** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 
vb@130
  1422
** that indicates what aspect of the [database connection] is being configured.
vb@130
  1423
** Subsequent arguments vary depending on the configuration verb.
vb@130
  1424
**
vb@130
  1425
** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
vb@130
  1426
** the call is considered successful.
vb@130
  1427
*/
Edouard@491
  1428
SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...);
vb@130
  1429
vb@130
  1430
/*
vb@130
  1431
** CAPI3REF: Memory Allocation Routines
vb@130
  1432
**
vb@130
  1433
** An instance of this object defines the interface between SQLite
vb@130
  1434
** and low-level memory allocation routines.
vb@130
  1435
**
vb@130
  1436
** This object is used in only one place in the SQLite interface.
vb@130
  1437
** A pointer to an instance of this object is the argument to
vb@130
  1438
** [sqlite3_config()] when the configuration option is
vb@130
  1439
** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].  
vb@130
  1440
** By creating an instance of this object
vb@130
  1441
** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
vb@130
  1442
** during configuration, an application can specify an alternative
vb@130
  1443
** memory allocation subsystem for SQLite to use for all of its
vb@130
  1444
** dynamic memory needs.
vb@130
  1445
**
vb@130
  1446
** Note that SQLite comes with several [built-in memory allocators]
vb@130
  1447
** that are perfectly adequate for the overwhelming majority of applications
vb@130
  1448
** and that this object is only useful to a tiny minority of applications
vb@130
  1449
** with specialized memory allocation requirements.  This object is
vb@130
  1450
** also used during testing of SQLite in order to specify an alternative
vb@130
  1451
** memory allocator that simulates memory out-of-memory conditions in
vb@130
  1452
** order to verify that SQLite recovers gracefully from such
vb@130
  1453
** conditions.
vb@130
  1454
**
vb@130
  1455
** The xMalloc, xRealloc, and xFree methods must work like the
vb@130
  1456
** malloc(), realloc() and free() functions from the standard C library.
vb@130
  1457
** ^SQLite guarantees that the second argument to
vb@130
  1458
** xRealloc is always a value returned by a prior call to xRoundup.
vb@130
  1459
**
vb@130
  1460
** xSize should return the allocated size of a memory allocation
vb@130
  1461
** previously obtained from xMalloc or xRealloc.  The allocated size
vb@130
  1462
** is always at least as big as the requested size but may be larger.
vb@130
  1463
**
vb@130
  1464
** The xRoundup method returns what would be the allocated size of
vb@130
  1465
** a memory allocation given a particular requested size.  Most memory
vb@130
  1466
** allocators round up memory allocations at least to the next multiple
vb@130
  1467
** of 8.  Some allocators round up to a larger multiple or to a power of 2.
vb@130
  1468
** Every memory allocation request coming in through [sqlite3_malloc()]
vb@130
  1469
** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0, 
vb@130
  1470
** that causes the corresponding memory allocation to fail.
vb@130
  1471
**
vb@130
  1472
** The xInit method initializes the memory allocator.  For example,
vb@130
  1473
** it might allocate any require mutexes or initialize internal data
vb@130
  1474
** structures.  The xShutdown method is invoked (indirectly) by
vb@130
  1475
** [sqlite3_shutdown()] and should deallocate any resources acquired
vb@130
  1476
** by xInit.  The pAppData pointer is used as the only parameter to
vb@130
  1477
** xInit and xShutdown.
vb@130
  1478
**
vb@130
  1479
** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
vb@130
  1480
** the xInit method, so the xInit method need not be threadsafe.  The
vb@130
  1481
** xShutdown method is only called from [sqlite3_shutdown()] so it does
vb@130
  1482
** not need to be threadsafe either.  For all other methods, SQLite
vb@130
  1483
** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
vb@130
  1484
** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
vb@130
  1485
** it is by default) and so the methods are automatically serialized.
vb@130
  1486
** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
vb@130
  1487
** methods must be threadsafe or else make their own arrangements for
vb@130
  1488
** serialization.
vb@130
  1489
**
vb@130
  1490
** SQLite will never invoke xInit() more than once without an intervening
vb@130
  1491
** call to xShutdown().
vb@130
  1492
*/
vb@130
  1493
typedef struct sqlite3_mem_methods sqlite3_mem_methods;
vb@130
  1494
struct sqlite3_mem_methods {
vb@130
  1495
  void *(*xMalloc)(int);         /* Memory allocation function */
vb@130
  1496
  void (*xFree)(void*);          /* Free a prior allocation */
vb@130
  1497
  void *(*xRealloc)(void*,int);  /* Resize an allocation */
vb@130
  1498
  int (*xSize)(void*);           /* Return the size of an allocation */
vb@130
  1499
  int (*xRoundup)(int);          /* Round up request size to allocation size */
vb@130
  1500
  int (*xInit)(void*);           /* Initialize the memory allocator */
vb@130
  1501
  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
vb@130
  1502
  void *pAppData;                /* Argument to xInit() and xShutdown() */
vb@130
  1503
};
vb@130
  1504
vb@130
  1505
/*
vb@130
  1506
** CAPI3REF: Configuration Options
vb@130
  1507
** KEYWORDS: {configuration option}
vb@130
  1508
**
vb@130
  1509
** These constants are the available integer configuration options that
vb@130
  1510
** can be passed as the first argument to the [sqlite3_config()] interface.
vb@130
  1511
**
vb@130
  1512
** New configuration options may be added in future releases of SQLite.
vb@130
  1513
** Existing configuration options might be discontinued.  Applications
vb@130
  1514
** should check the return code from [sqlite3_config()] to make sure that
vb@130
  1515
** the call worked.  The [sqlite3_config()] interface will return a
vb@130
  1516
** non-zero [error code] if a discontinued or unsupported configuration option
vb@130
  1517
** is invoked.
vb@130
  1518
**
vb@130
  1519
** <dl>
vb@130
  1520
** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
vb@130
  1521
** <dd>There are no arguments to this option.  ^This option sets the
vb@130
  1522
** [threading mode] to Single-thread.  In other words, it disables
vb@130
  1523
** all mutexing and puts SQLite into a mode where it can only be used
vb@130
  1524
** by a single thread.   ^If SQLite is compiled with
vb@130
  1525
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
vb@130
  1526
** it is not possible to change the [threading mode] from its default
vb@130
  1527
** value of Single-thread and so [sqlite3_config()] will return 
vb@130
  1528
** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
vb@130
  1529
** configuration option.</dd>
vb@130
  1530
**
vb@130
  1531
** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
vb@130
  1532
** <dd>There are no arguments to this option.  ^This option sets the
vb@130
  1533
** [threading mode] to Multi-thread.  In other words, it disables
vb@130
  1534
** mutexing on [database connection] and [prepared statement] objects.
vb@130
  1535
** The application is responsible for serializing access to
vb@130
  1536
** [database connections] and [prepared statements].  But other mutexes
vb@130
  1537
** are enabled so that SQLite will be safe to use in a multi-threaded
vb@130
  1538
** environment as long as no two threads attempt to use the same
vb@130
  1539
** [database connection] at the same time.  ^If SQLite is compiled with
vb@130
  1540
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
vb@130
  1541
** it is not possible to set the Multi-thread [threading mode] and
vb@130
  1542
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
vb@130
  1543
** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
vb@130
  1544
**
vb@130
  1545
** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
vb@130
  1546
** <dd>There are no arguments to this option.  ^This option sets the
vb@130
  1547
** [threading mode] to Serialized. In other words, this option enables
vb@130
  1548
** all mutexes including the recursive
vb@130
  1549
** mutexes on [database connection] and [prepared statement] objects.
vb@130
  1550
** In this mode (which is the default when SQLite is compiled with
vb@130
  1551
** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
vb@130
  1552
** to [database connections] and [prepared statements] so that the
vb@130
  1553
** application is free to use the same [database connection] or the
vb@130
  1554
** same [prepared statement] in different threads at the same time.
vb@130
  1555
** ^If SQLite is compiled with
vb@130
  1556
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
vb@130
  1557
** it is not possible to set the Serialized [threading mode] and
vb@130
  1558
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
vb@130
  1559
** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
vb@130
  1560
**
vb@130
  1561
** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
Edouard@491
  1562
** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 
Edouard@491
  1563
** a pointer to an instance of the [sqlite3_mem_methods] structure.
Edouard@491
  1564
** The argument specifies
vb@130
  1565
** alternative low-level memory allocation routines to be used in place of
vb@130
  1566
** the memory allocation routines built into SQLite.)^ ^SQLite makes
vb@130
  1567
** its own private copy of the content of the [sqlite3_mem_methods] structure
vb@130
  1568
** before the [sqlite3_config()] call returns.</dd>
vb@130
  1569
**
vb@130
  1570
** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
Edouard@491
  1571
** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
Edouard@491
  1572
** is a pointer to an instance of the [sqlite3_mem_methods] structure.
Edouard@491
  1573
** The [sqlite3_mem_methods]
vb@130
  1574
** structure is filled with the currently defined memory allocation routines.)^
vb@130
  1575
** This option can be used to overload the default memory allocation
vb@130
  1576
** routines with a wrapper that simulations memory allocation failure or
vb@130
  1577
** tracks memory usage, for example. </dd>
vb@130
  1578
**
vb@130
  1579
** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
Edouard@491
  1580
** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
Edouard@491
  1581
** interpreted as a boolean, which enables or disables the collection of
Edouard@491
  1582
** memory allocation statistics. ^(When memory allocation statistics are
Edouard@491
  1583
** disabled, the following SQLite interfaces become non-operational:
vb@130
  1584
**   <ul>
vb@130
  1585
**   <li> [sqlite3_memory_used()]
vb@130
  1586
**   <li> [sqlite3_memory_highwater()]
vb@130
  1587
**   <li> [sqlite3_soft_heap_limit64()]
Edouard@491
  1588
**   <li> [sqlite3_status64()]
vb@130
  1589
**   </ul>)^
vb@130
  1590
** ^Memory allocation statistics are enabled by default unless SQLite is
vb@130
  1591
** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
vb@130
  1592
** allocation statistics are disabled by default.
vb@130
  1593
** </dd>
vb@130
  1594
**
vb@130
  1595
** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
Edouard@491
  1596
** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer
Edouard@491
  1597
** that SQLite can use for scratch memory.  ^(There are three arguments
Edouard@491
  1598
** to SQLITE_CONFIG_SCRATCH:  A pointer an 8-byte
vb@130
  1599
** aligned memory buffer from which the scratch allocations will be
vb@130
  1600
** drawn, the size of each scratch allocation (sz),
Edouard@491
  1601
** and the maximum number of scratch allocations (N).)^
vb@130
  1602
** The first argument must be a pointer to an 8-byte aligned buffer
vb@130
  1603
** of at least sz*N bytes of memory.
Edouard@491
  1604
** ^SQLite will not use more than one scratch buffers per thread.
Edouard@491
  1605
** ^SQLite will never request a scratch buffer that is more than 6
Edouard@491
  1606
** times the database page size.
Edouard@491
  1607
** ^If SQLite needs needs additional
vb@130
  1608
** scratch memory beyond what is provided by this configuration option, then 
Edouard@491
  1609
** [sqlite3_malloc()] will be used to obtain the memory needed.<p>
Edouard@491
  1610
** ^When the application provides any amount of scratch memory using
Edouard@491
  1611
** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large
Edouard@491
  1612
** [sqlite3_malloc|heap allocations].
Edouard@491
  1613
** This can help [Robson proof|prevent memory allocation failures] due to heap
Edouard@491
  1614
** fragmentation in low-memory embedded systems.
Edouard@491
  1615
** </dd>
vb@130
  1616
**
vb@130
  1617
** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
Edouard@491
  1618
** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
Edouard@491
  1619
** that SQLite can use for the database page cache with the default page
Edouard@491
  1620
** cache implementation.  
Edouard@491
  1621
** This configuration option is a no-op if an application-define page
Edouard@491
  1622
** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
Edouard@491
  1623
** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
Edouard@491
  1624
** 8-byte aligned memory (pMem), the size of each page cache line (sz),
Edouard@491
  1625
** and the number of cache lines (N).
vb@130
  1626
** The sz argument should be the size of the largest database page
Edouard@491
  1627
** (a power of two between 512 and 65536) plus some extra bytes for each
Edouard@491
  1628
** page header.  ^The number of extra bytes needed by the page header
Edouard@491
  1629
** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
Edouard@491
  1630
** ^It is harmless, apart from the wasted memory,
Edouard@491
  1631
** for the sz parameter to be larger than necessary.  The pMem
Edouard@491
  1632
** argument must be either a NULL pointer or a pointer to an 8-byte
Edouard@491
  1633
** aligned block of memory of at least sz*N bytes, otherwise
Edouard@491
  1634
** subsequent behavior is undefined.
Edouard@491
  1635
** ^When pMem is not NULL, SQLite will strive to use the memory provided
Edouard@491
  1636
** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
Edouard@491
  1637
** a page cache line is larger than sz bytes or if all of the pMem buffer
Edouard@491
  1638
** is exhausted.
Edouard@491
  1639
** ^If pMem is NULL and N is non-zero, then each database connection
Edouard@491
  1640
** does an initial bulk allocation for page cache memory
Edouard@491
  1641
** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
Edouard@491
  1642
** of -1024*N bytes if N is negative, . ^If additional
Edouard@491
  1643
** page cache memory is needed beyond what is provided by the initial
Edouard@491
  1644
** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
Edouard@491
  1645
** additional cache line. </dd>
vb@130
  1646
**
vb@130
  1647
** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
Edouard@491
  1648
** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 
Edouard@491
  1649
** that SQLite will use for all of its dynamic memory allocation needs
Edouard@491
  1650
** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and
Edouard@491
  1651
** [SQLITE_CONFIG_PAGECACHE].
Edouard@491
  1652
** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
Edouard@491
  1653
** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
Edouard@491
  1654
** [SQLITE_ERROR] if invoked otherwise.
Edouard@491
  1655
** ^There are three arguments to SQLITE_CONFIG_HEAP:
Edouard@491
  1656
** An 8-byte aligned pointer to the memory,
vb@130
  1657
** the number of bytes in the memory buffer, and the minimum allocation size.
vb@130
  1658
** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
vb@130
  1659
** to using its default memory allocator (the system malloc() implementation),
vb@130
  1660
** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
Edouard@491
  1661
** memory pointer is not NULL then the alternative memory
vb@130
  1662
** allocator is engaged to handle all of SQLites memory allocation needs.
vb@130
  1663
** The first pointer (the memory pointer) must be aligned to an 8-byte
vb@130
  1664
** boundary or subsequent behavior of SQLite will be undefined.
vb@130
  1665
** The minimum allocation size is capped at 2**12. Reasonable values
vb@130
  1666
** for the minimum allocation size are 2**5 through 2**8.</dd>
vb@130
  1667
**
vb@130
  1668
** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
Edouard@491
  1669
** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
Edouard@491
  1670
** pointer to an instance of the [sqlite3_mutex_methods] structure.
Edouard@491
  1671
** The argument specifies alternative low-level mutex routines to be used
Edouard@491
  1672
** in place the mutex routines built into SQLite.)^  ^SQLite makes a copy of
Edouard@491
  1673
** the content of the [sqlite3_mutex_methods] structure before the call to
vb@130
  1674
** [sqlite3_config()] returns. ^If SQLite is compiled with
vb@130
  1675
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
vb@130
  1676
** the entire mutexing subsystem is omitted from the build and hence calls to
vb@130
  1677
** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
vb@130
  1678
** return [SQLITE_ERROR].</dd>
vb@130
  1679
**
vb@130
  1680
** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
Edouard@491
  1681
** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
Edouard@491
  1682
** is a pointer to an instance of the [sqlite3_mutex_methods] structure.  The
vb@130
  1683
** [sqlite3_mutex_methods]
vb@130
  1684
** structure is filled with the currently defined mutex routines.)^
vb@130
  1685
** This option can be used to overload the default mutex allocation
vb@130
  1686
** routines with a wrapper used to track mutex usage for performance
vb@130
  1687
** profiling or testing, for example.   ^If SQLite is compiled with
vb@130
  1688
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
vb@130
  1689
** the entire mutexing subsystem is omitted from the build and hence calls to
vb@130
  1690
** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
vb@130
  1691
** return [SQLITE_ERROR].</dd>
vb@130
  1692
**
vb@130
  1693
** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
Edouard@491
  1694
** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
Edouard@491
  1695
** the default size of lookaside memory on each [database connection].
Edouard@491
  1696
** The first argument is the
vb@130
  1697
** size of each lookaside buffer slot and the second is the number of
Edouard@491
  1698
** slots allocated to each database connection.)^  ^(SQLITE_CONFIG_LOOKASIDE
Edouard@491
  1699
** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
Edouard@491
  1700
** option to [sqlite3_db_config()] can be used to change the lookaside
vb@130
  1701
** configuration on individual connections.)^ </dd>
vb@130
  1702
**
vb@130
  1703
** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
Edouard@491
  1704
** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 
Edouard@491
  1705
** a pointer to an [sqlite3_pcache_methods2] object.  This object specifies
Edouard@491
  1706
** the interface to a custom page cache implementation.)^
Edouard@491
  1707
** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
vb@130
  1708
**
vb@130
  1709
** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
Edouard@491
  1710
** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
Edouard@491
  1711
** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of
Edouard@491
  1712
** the current page cache implementation into that object.)^ </dd>
vb@130
  1713
**
vb@130
  1714
** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
vb@130
  1715
** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
vb@130
  1716
** global [error log].
vb@130
  1717
** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
vb@130
  1718
** function with a call signature of void(*)(void*,int,const char*), 
vb@130
  1719
** and a pointer to void. ^If the function pointer is not NULL, it is
vb@130
  1720
** invoked by [sqlite3_log()] to process each logging event.  ^If the
vb@130
  1721
** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
vb@130
  1722
** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
vb@130
  1723
** passed through as the first parameter to the application-defined logger
vb@130
  1724
** function whenever that function is invoked.  ^The second parameter to
vb@130
  1725
** the logger function is a copy of the first parameter to the corresponding
vb@130
  1726
** [sqlite3_log()] call and is intended to be a [result code] or an
vb@130
  1727
** [extended result code].  ^The third parameter passed to the logger is
vb@130
  1728
** log message after formatting via [sqlite3_snprintf()].
vb@130
  1729
** The SQLite logging interface is not reentrant; the logger function
vb@130
  1730
** supplied by the application must not invoke any SQLite interface.
vb@130
  1731
** In a multi-threaded application, the application-defined logger
vb@130
  1732
** function must be threadsafe. </dd>
vb@130
  1733
**
vb@130
  1734
** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
Edouard@491
  1735
** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
Edouard@491
  1736
** If non-zero, then URI handling is globally enabled. If the parameter is zero,
Edouard@491
  1737
** then URI handling is globally disabled.)^ ^If URI handling is globally
Edouard@491
  1738
** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
Edouard@491
  1739
** [sqlite3_open16()] or
vb@130
  1740
** specified as part of [ATTACH] commands are interpreted as URIs, regardless
vb@130
  1741
** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
vb@130
  1742
** connection is opened. ^If it is globally disabled, filenames are
vb@130
  1743
** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
vb@130
  1744
** database connection is opened. ^(By default, URI handling is globally
vb@130
  1745
** disabled. The default value may be changed by compiling with the
vb@130
  1746
** [SQLITE_USE_URI] symbol defined.)^
vb@130
  1747
**
vb@130
  1748
** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
Edouard@491
  1749
** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
Edouard@491
  1750
** argument which is interpreted as a boolean in order to enable or disable
Edouard@491
  1751
** the use of covering indices for full table scans in the query optimizer.
Edouard@491
  1752
** ^The default setting is determined
vb@130
  1753
** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
vb@130
  1754
** if that compile-time option is omitted.
vb@130
  1755
** The ability to disable the use of covering indices for full table scans
vb@130
  1756
** is because some incorrectly coded legacy applications might malfunction
vb@130
  1757
** when the optimization is enabled.  Providing the ability to
vb@130
  1758
** disable the optimization allows the older, buggy application code to work
vb@130
  1759
** without change even with newer versions of SQLite.
vb@130
  1760
**
vb@130
  1761
** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
vb@130
  1762
** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
vb@130
  1763
** <dd> These options are obsolete and should not be used by new code.
vb@130
  1764
** They are retained for backwards compatibility but are now no-ops.
vb@130
  1765
** </dd>
vb@130
  1766
**
vb@130
  1767
** [[SQLITE_CONFIG_SQLLOG]]
vb@130
  1768
** <dt>SQLITE_CONFIG_SQLLOG
vb@130
  1769
** <dd>This option is only available if sqlite is compiled with the
vb@130
  1770
** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
vb@130
  1771
** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
vb@130
  1772
** The second should be of type (void*). The callback is invoked by the library
vb@130
  1773
** in three separate circumstances, identified by the value passed as the
vb@130
  1774
** fourth parameter. If the fourth parameter is 0, then the database connection
vb@130
  1775
** passed as the second argument has just been opened. The third argument
vb@130
  1776
** points to a buffer containing the name of the main database file. If the
vb@130
  1777
** fourth parameter is 1, then the SQL statement that the third parameter
vb@130
  1778
** points to has just been executed. Or, if the fourth parameter is 2, then
vb@130
  1779
** the connection being passed as the second parameter is being closed. The
vb@130
  1780
** third parameter is passed NULL In this case.  An example of using this
vb@130
  1781
** configuration option can be seen in the "test_sqllog.c" source file in
vb@130
  1782
** the canonical SQLite source tree.</dd>
vb@130
  1783
**
vb@130
  1784
** [[SQLITE_CONFIG_MMAP_SIZE]]
vb@130
  1785
** <dt>SQLITE_CONFIG_MMAP_SIZE
vb@130
  1786
** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
vb@130
  1787
** that are the default mmap size limit (the default setting for
vb@130
  1788
** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
vb@130
  1789
** ^The default setting can be overridden by each database connection using
vb@130
  1790
** either the [PRAGMA mmap_size] command, or by using the
vb@130
  1791
** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
Edouard@491
  1792
** will be silently truncated if necessary so that it does not exceed the
Edouard@491
  1793
** compile-time maximum mmap size set by the
vb@130
  1794
** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
vb@130
  1795
** ^If either argument to this option is negative, then that argument is
vb@130
  1796
** changed to its compile-time default.
vb@130
  1797
**
vb@130
  1798
** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
vb@130
  1799
** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
Edouard@491
  1800
** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
Edouard@491
  1801
** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
Edouard@491
  1802
** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
vb@130
  1803
** that specifies the maximum size of the created heap.
Edouard@491
  1804
**
Edouard@491
  1805
** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
Edouard@491
  1806
** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
Edouard@491
  1807
** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
Edouard@491
  1808
** is a pointer to an integer and writes into that integer the number of extra
Edouard@491
  1809
** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
Edouard@491
  1810
** The amount of extra space required can change depending on the compiler,
Edouard@491
  1811
** target platform, and SQLite version.
Edouard@491
  1812
**
Edouard@491
  1813
** [[SQLITE_CONFIG_PMASZ]]
Edouard@491
  1814
** <dt>SQLITE_CONFIG_PMASZ
Edouard@491
  1815
** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
Edouard@491
  1816
** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
Edouard@491
  1817
** sorter to that integer.  The default minimum PMA Size is set by the
Edouard@491
  1818
** [SQLITE_SORTER_PMASZ] compile-time option.  New threads are launched
Edouard@491
  1819
** to help with sort operations when multithreaded sorting
Edouard@491
  1820
** is enabled (using the [PRAGMA threads] command) and the amount of content
Edouard@491
  1821
** to be sorted exceeds the page size times the minimum of the
Edouard@491
  1822
** [PRAGMA cache_size] setting and this value.
vb@716
  1823
**
vb@716
  1824
** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
vb@716
  1825
** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
vb@716
  1826
** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
vb@716
  1827
** becomes the [statement journal] spill-to-disk threshold.  
vb@716
  1828
** [Statement journals] are held in memory until their size (in bytes)
vb@716
  1829
** exceeds this threshold, at which point they are written to disk.
vb@716
  1830
** Or if the threshold is -1, statement journals are always held
vb@716
  1831
** exclusively in memory.
vb@716
  1832
** Since many statement journals never become large, setting the spill
vb@716
  1833
** threshold to a value such as 64KiB can greatly reduce the amount of
vb@716
  1834
** I/O required to support statement rollback.
vb@716
  1835
** The default value for this setting is controlled by the
vb@716
  1836
** [SQLITE_STMTJRNL_SPILL] compile-time option.
vb@130
  1837
** </dl>
vb@130
  1838
*/
vb@130
  1839
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
vb@130
  1840
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
vb@130
  1841
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
vb@130
  1842
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
vb@130
  1843
#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
vb@130
  1844
#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
vb@130
  1845
#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
vb@130
  1846
#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
vb@130
  1847
#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
vb@130
  1848
#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
vb@130
  1849
#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
vb@130
  1850
/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 
vb@130
  1851
#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
vb@130
  1852
#define SQLITE_CONFIG_PCACHE       14  /* no-op */
vb@130
  1853
#define SQLITE_CONFIG_GETPCACHE    15  /* no-op */
vb@130
  1854
#define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
vb@130
  1855
#define SQLITE_CONFIG_URI          17  /* int */
vb@130
  1856
#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
vb@130
  1857
#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
vb@130
  1858
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
vb@130
  1859
#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
vb@130
  1860
#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
vb@130
  1861
#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
Edouard@491
  1862
#define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */
Edouard@491
  1863
#define SQLITE_CONFIG_PMASZ               25  /* unsigned int szPma */
vb@716
  1864
#define SQLITE_CONFIG_STMTJRNL_SPILL      26  /* int nByte */
vb@130
  1865
vb@130
  1866
/*
vb@130
  1867
** CAPI3REF: Database Connection Configuration Options
vb@130
  1868
**
vb@130
  1869
** These constants are the available integer configuration options that
vb@130
  1870
** can be passed as the second argument to the [sqlite3_db_config()] interface.
vb@130
  1871
**
vb@130
  1872
** New configuration options may be added in future releases of SQLite.
vb@130
  1873
** Existing configuration options might be discontinued.  Applications
vb@130
  1874
** should check the return code from [sqlite3_db_config()] to make sure that
vb@130
  1875
** the call worked.  ^The [sqlite3_db_config()] interface will return a
vb@130
  1876
** non-zero [error code] if a discontinued or unsupported configuration option
vb@130
  1877
** is invoked.
vb@130
  1878
**
vb@130
  1879
** <dl>
vb@130
  1880
** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
vb@130
  1881
** <dd> ^This option takes three additional arguments that determine the 
vb@130
  1882
** [lookaside memory allocator] configuration for the [database connection].
vb@130
  1883
** ^The first argument (the third parameter to [sqlite3_db_config()] is a
vb@130
  1884
** pointer to a memory buffer to use for lookaside memory.
vb@130
  1885
** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
vb@130
  1886
** may be NULL in which case SQLite will allocate the
vb@130
  1887
** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
vb@130
  1888
** size of each lookaside buffer slot.  ^The third argument is the number of
vb@130
  1889
** slots.  The size of the buffer in the first argument must be greater than
vb@130
  1890
** or equal to the product of the second and third arguments.  The buffer
vb@130
  1891
** must be aligned to an 8-byte boundary.  ^If the second argument to
vb@130
  1892
** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
vb@130
  1893
** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
vb@130
  1894
** configuration for a database connection can only be changed when that
vb@130
  1895
** connection is not currently using lookaside memory, or in other words
vb@130
  1896
** when the "current value" returned by
vb@130
  1897
** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
vb@130
  1898
** Any attempt to change the lookaside memory configuration when lookaside
vb@130
  1899
** memory is in use leaves the configuration unchanged and returns 
vb@130
  1900
** [SQLITE_BUSY].)^</dd>
vb@130
  1901
**
vb@130
  1902
** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
vb@130
  1903
** <dd> ^This option is used to enable or disable the enforcement of
vb@130
  1904
** [foreign key constraints].  There should be two additional arguments.
vb@130
  1905
** The first argument is an integer which is 0 to disable FK enforcement,
vb@130
  1906
** positive to enable FK enforcement or negative to leave FK enforcement
vb@130
  1907
** unchanged.  The second parameter is a pointer to an integer into which
vb@130
  1908
** is written 0 or 1 to indicate whether FK enforcement is off or on
vb@130
  1909
** following this call.  The second parameter may be a NULL pointer, in
vb@130
  1910
** which case the FK enforcement setting is not reported back. </dd>
vb@130
  1911
**
vb@130
  1912
** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
vb@130
  1913
** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
vb@130
  1914
** There should be two additional arguments.
vb@130
  1915
** The first argument is an integer which is 0 to disable triggers,
vb@130
  1916
** positive to enable triggers or negative to leave the setting unchanged.
vb@130
  1917
** The second parameter is a pointer to an integer into which
vb@130
  1918
** is written 0 or 1 to indicate whether triggers are disabled or enabled
vb@130
  1919
** following this call.  The second parameter may be a NULL pointer, in
vb@130
  1920
** which case the trigger setting is not reported back. </dd>
vb@130
  1921
**
vb@716
  1922
** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
vb@716
  1923
** <dd> ^This option is used to enable or disable the two-argument
vb@716
  1924
** version of the [fts3_tokenizer()] function which is part of the
vb@716
  1925
** [FTS3] full-text search engine extension.
vb@716
  1926
** There should be two additional arguments.
vb@716
  1927
** The first argument is an integer which is 0 to disable fts3_tokenizer() or
vb@716
  1928
** positive to enable fts3_tokenizer() or negative to leave the setting
vb@716
  1929
** unchanged.
vb@716
  1930
** The second parameter is a pointer to an integer into which
vb@716
  1931
** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
vb@716
  1932
** following this call.  The second parameter may be a NULL pointer, in
vb@716
  1933
** which case the new setting is not reported back. </dd>
vb@716
  1934
**
vb@716
  1935
** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
vb@716
  1936
** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
vb@716
  1937
** interface independently of the [load_extension()] SQL function.
vb@716
  1938
** The [sqlite3_enable_load_extension()] API enables or disables both the
vb@716
  1939
** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
vb@716
  1940
** There should be two additional arguments.
vb@716
  1941
** When the first argument to this interface is 1, then only the C-API is
vb@716
  1942
** enabled and the SQL function remains disabled.  If the first argment to
vb@716
  1943
** this interface is 0, then both the C-API and the SQL function are disabled.
vb@716
  1944
** If the first argument is -1, then no changes are made to state of either the
vb@716
  1945
** C-API or the SQL function.
vb@716
  1946
** The second parameter is a pointer to an integer into which
vb@716
  1947
** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
vb@716
  1948
** is disabled or enabled following this call.  The second parameter may
vb@716
  1949
** be a NULL pointer, in which case the new setting is not reported back.
vb@716
  1950
** </dd>
vb@716
  1951
**
vb@130
  1952
** </dl>
vb@130
  1953
*/
vb@716
  1954
#define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
vb@716
  1955
#define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
vb@716
  1956
#define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
vb@716
  1957
#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
vb@716
  1958
#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
vb@130
  1959
vb@130
  1960
vb@130
  1961
/*
vb@130
  1962
** CAPI3REF: Enable Or Disable Extended Result Codes
Edouard@491
  1963
** METHOD: sqlite3
vb@130
  1964
**
vb@130
  1965
** ^The sqlite3_extended_result_codes() routine enables or disables the
vb@130
  1966
** [extended result codes] feature of SQLite. ^The extended result
vb@130
  1967
** codes are disabled by default for historical compatibility.
vb@130
  1968
*/
Edouard@491
  1969
SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff);
vb@130
  1970
vb@130
  1971
/*
vb@130
  1972
** CAPI3REF: Last Insert Rowid
Edouard@491
  1973
** METHOD: sqlite3
vb@130
  1974
**
vb@130
  1975
** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
vb@130
  1976
** has a unique 64-bit signed
vb@130
  1977
** integer key called the [ROWID | "rowid"]. ^The rowid is always available
vb@130
  1978
** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
vb@130
  1979
** names are not also used by explicitly declared columns. ^If
vb@130
  1980
** the table has a column of type [INTEGER PRIMARY KEY] then that column
vb@130
  1981
** is another alias for the rowid.
vb@130
  1982
**
vb@130
  1983
** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 
vb@130
  1984
** most recent successful [INSERT] into a rowid table or [virtual table]
vb@130
  1985
** on database connection D.
vb@130
  1986
** ^Inserts into [WITHOUT ROWID] tables are not recorded.
vb@130
  1987
** ^If no successful [INSERT]s into rowid tables
vb@130
  1988
** have ever occurred on the database connection D, 
vb@130
  1989
** then sqlite3_last_insert_rowid(D) returns zero.
vb@130
  1990
**
vb@130
  1991
** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
vb@130
  1992
** method, then this routine will return the [rowid] of the inserted
vb@130
  1993
** row as long as the trigger or virtual table method is running.
vb@130
  1994
** But once the trigger or virtual table method ends, the value returned 
vb@130
  1995
** by this routine reverts to what it was before the trigger or virtual
vb@130
  1996
** table method began.)^
vb@130
  1997
**
vb@130
  1998
** ^An [INSERT] that fails due to a constraint violation is not a
vb@130
  1999
** successful [INSERT] and does not change the value returned by this
vb@130
  2000
** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
vb@130
  2001
** and INSERT OR ABORT make no changes to the return value of this
vb@130
  2002
** routine when their insertion fails.  ^(When INSERT OR REPLACE
vb@130
  2003
** encounters a constraint violation, it does not fail.  The
vb@130
  2004
** INSERT continues to completion after deleting rows that caused
vb@130
  2005
** the constraint problem so INSERT OR REPLACE will always change
vb@130
  2006
** the return value of this interface.)^
vb@130
  2007
**
vb@130
  2008
** ^For the purposes of this routine, an [INSERT] is considered to
vb@130
  2009
** be successful even if it is subsequently rolled back.
vb@130
  2010
**
vb@130
  2011
** This function is accessible to SQL statements via the
vb@130
  2012
** [last_insert_rowid() SQL function].
vb@130
  2013
**
vb@130
  2014
** If a separate thread performs a new [INSERT] on the same
vb@130
  2015
** database connection while the [sqlite3_last_insert_rowid()]
vb@130
  2016
** function is running and thus changes the last insert [rowid],
vb@130
  2017
** then the value returned by [sqlite3_last_insert_rowid()] is
vb@130
  2018
** unpredictable and might not equal either the old or the new
vb@130
  2019
** last insert [rowid].
vb@130
  2020
*/
Edouard@491
  2021
SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*);
vb@130
  2022
vb@130
  2023
/*
vb@130
  2024
** CAPI3REF: Count The Number Of Rows Modified
Edouard@491
  2025
** METHOD: sqlite3
Edouard@491
  2026
**
Edouard@491
  2027
** ^This function returns the number of rows modified, inserted or
Edouard@491
  2028
** deleted by the most recently completed INSERT, UPDATE or DELETE
Edouard@491
  2029
** statement on the database connection specified by the only parameter.
Edouard@491
  2030
** ^Executing any other type of SQL statement does not modify the value
Edouard@491
  2031
** returned by this function.
Edouard@491
  2032
**
Edouard@491
  2033
** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
Edouard@491
  2034
** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 
Edouard@491
  2035
** [foreign key actions] or [REPLACE] constraint resolution are not counted.
Edouard@491
  2036
** 
Edouard@491
  2037
** Changes to a view that are intercepted by 
Edouard@491
  2038
** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 
Edouard@491
  2039
** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 
Edouard@491
  2040
** DELETE statement run on a view is always zero. Only changes made to real 
Edouard@491
  2041
** tables are counted.
Edouard@491
  2042
**
Edouard@491
  2043
** Things are more complicated if the sqlite3_changes() function is
Edouard@491
  2044
** executed while a trigger program is running. This may happen if the
Edouard@491
  2045
** program uses the [changes() SQL function], or if some other callback
Edouard@491
  2046
** function invokes sqlite3_changes() directly. Essentially:
Edouard@491
  2047
** 
Edouard@491
  2048
** <ul>
Edouard@491
  2049
**   <li> ^(Before entering a trigger program the value returned by
Edouard@491
  2050
**        sqlite3_changes() function is saved. After the trigger program 
Edouard@491
  2051
**        has finished, the original value is restored.)^
Edouard@491
  2052
** 
Edouard@491
  2053
**   <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 
Edouard@491
  2054
**        statement sets the value returned by sqlite3_changes() 
Edouard@491
  2055
**        upon completion as normal. Of course, this value will not include 
Edouard@491
  2056
**        any changes performed by sub-triggers, as the sqlite3_changes() 
Edouard@491
  2057
**        value will be saved and restored after each sub-trigger has run.)^
Edouard@491
  2058
** </ul>
Edouard@491
  2059
** 
Edouard@491
  2060
** ^This means that if the changes() SQL function (or similar) is used
Edouard@491
  2061
** by the first INSERT, UPDATE or DELETE statement within a trigger, it 
Edouard@491
  2062
** returns the value as set when the calling statement began executing.
Edouard@491
  2063
** ^If it is used by the second or subsequent such statement within a trigger 
Edouard@491
  2064
** program, the value returned reflects the number of rows modified by the 
Edouard@491
  2065
** previous INSERT, UPDATE or DELETE statement within the same trigger.
vb@130
  2066
**
vb@130
  2067
** See also the [sqlite3_total_changes()] interface, the
vb@130
  2068
** [count_changes pragma], and the [changes() SQL function].
vb@130
  2069
**
vb@130
  2070
** If a separate thread makes changes on the same database connection
vb@130
  2071
** while [sqlite3_changes()] is running then the value returned
vb@130
  2072
** is unpredictable and not meaningful.
vb@130
  2073
*/
Edouard@491
  2074
SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*);
vb@130
  2075
vb@130
  2076
/*
vb@130
  2077
** CAPI3REF: Total Number Of Rows Modified
Edouard@491
  2078
** METHOD: sqlite3
Edouard@491
  2079
**
Edouard@491
  2080
** ^This function returns the total number of rows inserted, modified or
Edouard@491
  2081
** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
Edouard@491
  2082
** since the database connection was opened, including those executed as
Edouard@491
  2083
** part of trigger programs. ^Executing any other type of SQL statement
Edouard@491
  2084
** does not affect the value returned by sqlite3_total_changes().
Edouard@491
  2085
** 
Edouard@491
  2086
** ^Changes made as part of [foreign key actions] are included in the
Edouard@491
  2087
** count, but those made as part of REPLACE constraint resolution are
Edouard@491
  2088
** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 
Edouard@491
  2089
** are not counted.
Edouard@491
  2090
** 
vb@130
  2091
** See also the [sqlite3_changes()] interface, the
vb@130
  2092
** [count_changes pragma], and the [total_changes() SQL function].
vb@130
  2093
**
vb@130
  2094
** If a separate thread makes changes on the same database connection
vb@130
  2095
** while [sqlite3_total_changes()] is running then the value
vb@130
  2096
** returned is unpredictable and not meaningful.
vb@130
  2097
*/
Edouard@491
  2098
SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*);
vb@130
  2099
vb@130
  2100
/*
vb@130
  2101
** CAPI3REF: Interrupt A Long-Running Query
Edouard@491
  2102
** METHOD: sqlite3
vb@130
  2103
**
vb@130
  2104
** ^This function causes any pending database operation to abort and
vb@130
  2105
** return at its earliest opportunity. This routine is typically
vb@130
  2106
** called in response to a user action such as pressing "Cancel"
vb@130
  2107
** or Ctrl-C where the user wants a long query operation to halt
vb@130
  2108
** immediately.
vb@130
  2109
**
vb@130
  2110
** ^It is safe to call this routine from a thread different from the
vb@130
  2111
** thread that is currently running the database operation.  But it
vb@130
  2112
** is not safe to call this routine with a [database connection] that
vb@130
  2113
** is closed or might close before sqlite3_interrupt() returns.
vb@130
  2114
**
vb@130
  2115
** ^If an SQL operation is very nearly finished at the time when
vb@130
  2116
** sqlite3_interrupt() is called, then it might not have an opportunity
vb@130
  2117
** to be interrupted and might continue to completion.
vb@130
  2118
**
vb@130
  2119
** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
vb@130
  2120
** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
vb@130
  2121
** that is inside an explicit transaction, then the entire transaction
vb@130
  2122
** will be rolled back automatically.
vb@130
  2123
**
vb@130
  2124
** ^The sqlite3_interrupt(D) call is in effect until all currently running
vb@130
  2125
** SQL statements on [database connection] D complete.  ^Any new SQL statements
vb@130
  2126
** that are started after the sqlite3_interrupt() call and before the 
vb@130
  2127
** running statements reaches zero are interrupted as if they had been
vb@130
  2128
** running prior to the sqlite3_interrupt() call.  ^New SQL statements
vb@130
  2129
** that are started after the running statement count reaches zero are
vb@130
  2130
** not effected by the sqlite3_interrupt().
vb@130
  2131
** ^A call to sqlite3_interrupt(D) that occurs when there are no running
vb@130
  2132
** SQL statements is a no-op and has no effect on SQL statements
vb@130
  2133
** that are started after the sqlite3_interrupt() call returns.
vb@130
  2134
**
vb@130
  2135
** If the database connection closes while [sqlite3_interrupt()]
vb@130
  2136
** is running then bad things will likely happen.
vb@130
  2137
*/
Edouard@491
  2138
SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*);
vb@130
  2139
vb@130
  2140
/*
vb@130
  2141
** CAPI3REF: Determine If An SQL Statement Is Complete
vb@130
  2142
**
vb@130
  2143
** These routines are useful during command-line input to determine if the
vb@130
  2144
** currently entered text seems to form a complete SQL statement or
vb@130
  2145
** if additional input is needed before sending the text into
vb@130
  2146
** SQLite for parsing.  ^These routines return 1 if the input string
vb@130
  2147
** appears to be a complete SQL statement.  ^A statement is judged to be
vb@130
  2148
** complete if it ends with a semicolon token and is not a prefix of a
vb@130
  2149
** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
vb@130
  2150
** string literals or quoted identifier names or comments are not
vb@130
  2151
** independent tokens (they are part of the token in which they are
vb@130
  2152
** embedded) and thus do not count as a statement terminator.  ^Whitespace
vb@130
  2153
** and comments that follow the final semicolon are ignored.
vb@130
  2154
**
vb@130
  2155
** ^These routines return 0 if the statement is incomplete.  ^If a
vb@130
  2156
** memory allocation fails, then SQLITE_NOMEM is returned.
vb@130
  2157
**
vb@130
  2158
** ^These routines do not parse the SQL statements thus
vb@130
  2159
** will not detect syntactically incorrect SQL.
vb@130
  2160
**
vb@130
  2161
** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 
vb@130
  2162
** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
vb@130
  2163
** automatically by sqlite3_complete16().  If that initialization fails,
vb@130
  2164
** then the return value from sqlite3_complete16() will be non-zero
vb@130
  2165
** regardless of whether or not the input SQL is complete.)^
vb@130
  2166
**
vb@130
  2167
** The input to [sqlite3_complete()] must be a zero-terminated
vb@130
  2168
** UTF-8 string.
vb@130
  2169
**
vb@130
  2170
** The input to [sqlite3_complete16()] must be a zero-terminated
vb@130
  2171
** UTF-16 string in native byte order.
vb@130
  2172
*/
Edouard@491
  2173
SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql);
Edouard@491
  2174
SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql);
vb@130
  2175
vb@130
  2176
/*
vb@130
  2177
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
Edouard@491
  2178
** KEYWORDS: {busy-handler callback} {busy handler}
Edouard@491
  2179
** METHOD: sqlite3
vb@130
  2180
**
vb@130
  2181
** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
vb@130
  2182
** that might be invoked with argument P whenever
vb@130
  2183
** an attempt is made to access a database table associated with
vb@130
  2184
** [database connection] D when another thread
vb@130
  2185
** or process has the table locked.
vb@130
  2186
** The sqlite3_busy_handler() interface is used to implement
vb@130
  2187
** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
vb@130
  2188
**
vb@130
  2189
** ^If the busy callback is NULL, then [SQLITE_BUSY]
vb@130
  2190
** is returned immediately upon encountering the lock.  ^If the busy callback
vb@130
  2191
** is not NULL, then the callback might be invoked with two arguments.
vb@130
  2192
**
vb@130
  2193
** ^The first argument to the busy handler is a copy of the void* pointer which
vb@130
  2194
** is the third argument to sqlite3_busy_handler().  ^The second argument to
vb@130
  2195
** the busy handler callback is the number of times that the busy handler has
Edouard@491
  2196
** been invoked previously for the same locking event.  ^If the
vb@130
  2197
** busy callback returns 0, then no additional attempts are made to
vb@130
  2198
** access the database and [SQLITE_BUSY] is returned
vb@130
  2199
** to the application.
vb@130
  2200
** ^If the callback returns non-zero, then another attempt
vb@130
  2201
** is made to access the database and the cycle repeats.
vb@130
  2202
**
vb@130
  2203
** The presence of a busy handler does not guarantee that it will be invoked
vb@130
  2204
** when there is lock contention. ^If SQLite determines that invoking the busy
vb@130
  2205
** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
vb@130
  2206
** to the application instead of invoking the 
vb@130
  2207
** busy handler.
vb@130
  2208
** Consider a scenario where one process is holding a read lock that
vb@130
  2209
** it is trying to promote to a reserved lock and
vb@130
  2210
** a second process is holding a reserved lock that it is trying
vb@130
  2211
** to promote to an exclusive lock.  The first process cannot proceed
vb@130
  2212
** because it is blocked by the second and the second process cannot
vb@130
  2213
** proceed because it is blocked by the first.  If both processes
vb@130
  2214
** invoke the busy handlers, neither will make any progress.  Therefore,
vb@130
  2215
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
vb@130
  2216
** will induce the first process to release its read lock and allow
vb@130
  2217
** the second process to proceed.
vb@130
  2218
**
vb@130
  2219
** ^The default busy callback is NULL.
vb@130
  2220
**
vb@130
  2221
** ^(There can only be a single busy handler defined for each
vb@130
  2222
** [database connection].  Setting a new busy handler clears any
vb@130
  2223
** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
vb@130
  2224
** or evaluating [PRAGMA busy_timeout=N] will change the
vb@130
  2225
** busy handler and thus clear any previously set busy handler.
vb@130
  2226
**
vb@130
  2227
** The busy callback should not take any actions which modify the
vb@130
  2228
** database connection that invoked the busy handler.  In other words,
vb@130
  2229
** the busy handler is not reentrant.  Any such actions
vb@130
  2230
** result in undefined behavior.
vb@130
  2231
** 
vb@130
  2232
** A busy handler must not close the database connection
vb@130
  2233
** or [prepared statement] that invoked the busy handler.
vb@130
  2234
*/
Edouard@491
  2235
SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
vb@130
  2236
vb@130
  2237
/*
vb@130
  2238
** CAPI3REF: Set A Busy Timeout
Edouard@491
  2239
** METHOD: sqlite3
vb@130
  2240
**
vb@130
  2241
** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
vb@130
  2242
** for a specified amount of time when a table is locked.  ^The handler
vb@130
  2243
** will sleep multiple times until at least "ms" milliseconds of sleeping
vb@130
  2244
** have accumulated.  ^After at least "ms" milliseconds of sleeping,
vb@130
  2245
** the handler returns 0 which causes [sqlite3_step()] to return
vb@130
  2246
** [SQLITE_BUSY].
vb@130
  2247
**
vb@130
  2248
** ^Calling this routine with an argument less than or equal to zero
vb@130
  2249
** turns off all busy handlers.
vb@130
  2250
**
vb@130
  2251
** ^(There can only be a single busy handler for a particular
Edouard@491
  2252
** [database connection] at any given moment.  If another busy handler
vb@130
  2253
** was defined  (using [sqlite3_busy_handler()]) prior to calling
vb@130
  2254
** this routine, that other busy handler is cleared.)^
vb@130
  2255
**
vb@130
  2256
** See also:  [PRAGMA busy_timeout]
vb@130
  2257
*/
Edouard@491
  2258
SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms);
vb@130
  2259
vb@130
  2260
/*
vb@130
  2261
** CAPI3REF: Convenience Routines For Running Queries
Edouard@491
  2262
** METHOD: sqlite3
vb@130
  2263
**
vb@130
  2264
** This is a legacy interface that is preserved for backwards compatibility.
vb@130
  2265
** Use of this interface is not recommended.
vb@130
  2266
**
vb@130
  2267
** Definition: A <b>result table</b> is memory data structure created by the
vb@130
  2268
** [sqlite3_get_table()] interface.  A result table records the
vb@130
  2269
** complete query results from one or more queries.
vb@130
  2270
**
vb@130
  2271
** The table conceptually has a number of rows and columns.  But
vb@130
  2272
** these numbers are not part of the result table itself.  These
vb@130
  2273
** numbers are obtained separately.  Let N be the number of rows
vb@130
  2274
** and M be the number of columns.
vb@130
  2275
**
vb@130
  2276
** A result table is an array of pointers to zero-terminated UTF-8 strings.
vb@130
  2277
** There are (N+1)*M elements in the array.  The first M pointers point
vb@130
  2278
** to zero-terminated strings that  contain the names of the columns.
vb@130
  2279
** The remaining entries all point to query results.  NULL values result
vb@130
  2280
** in NULL pointers.  All other values are in their UTF-8 zero-terminated
vb@130
  2281
** string representation as returned by [sqlite3_column_text()].
vb@130
  2282
**
vb@130
  2283
** A result table might consist of one or more memory allocations.
vb@130
  2284
** It is not safe to pass a result table directly to [sqlite3_free()].
vb@130
  2285
** A result table should be deallocated using [sqlite3_free_table()].
vb@130
  2286
**
vb@130
  2287
** ^(As an example of the result table format, suppose a query result
vb@130
  2288
** is as follows:
vb@130
  2289
**
vb@130
  2290
** <blockquote><pre>
vb@130
  2291
**        Name        | Age
vb@130
  2292
**        -----------------------
vb@130
  2293
**        Alice       | 43
vb@130
  2294
**        Bob         | 28
vb@130
  2295
**        Cindy       | 21
vb@130
  2296
** </pre></blockquote>
vb@130
  2297
**
vb@130
  2298
** There are two column (M==2) and three rows (N==3).  Thus the
vb@130
  2299
** result table has 8 entries.  Suppose the result table is stored
vb@130
  2300
** in an array names azResult.  Then azResult holds this content:
vb@130
  2301
**
vb@130
  2302
** <blockquote><pre>
vb@130
  2303
**        azResult&#91;0] = "Name";
vb@130
  2304
**        azResult&#91;1] = "Age";
vb@130
  2305
**        azResult&#91;2] = "Alice";
vb@130
  2306
**        azResult&#91;3] = "43";
vb@130
  2307
**        azResult&#91;4] = "Bob";
vb@130
  2308
**        azResult&#91;5] = "28";
vb@130
  2309
**        azResult&#91;6] = "Cindy";
vb@130
  2310
**        azResult&#91;7] = "21";
vb@130
  2311
** </pre></blockquote>)^
vb@130
  2312
**
vb@130
  2313
** ^The sqlite3_get_table() function evaluates one or more
vb@130
  2314
** semicolon-separated SQL statements in the zero-terminated UTF-8
vb@130
  2315
** string of its 2nd parameter and returns a result table to the
vb@130
  2316
** pointer given in its 3rd parameter.
vb@130
  2317
**
vb@130
  2318
** After the application has finished with the result from sqlite3_get_table(),
vb@130
  2319
** it must pass the result table pointer to sqlite3_free_table() in order to
vb@130
  2320
** release the memory that was malloced.  Because of the way the
vb@130
  2321
** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
vb@130
  2322
** function must not try to call [sqlite3_free()] directly.  Only
vb@130
  2323
** [sqlite3_free_table()] is able to release the memory properly and safely.
vb@130
  2324
**
vb@130
  2325
** The sqlite3_get_table() interface is implemented as a wrapper around
vb@130
  2326
** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
vb@130
  2327
** to any internal data structures of SQLite.  It uses only the public
vb@130
  2328
** interface defined here.  As a consequence, errors that occur in the
vb@130
  2329
** wrapper layer outside of the internal [sqlite3_exec()] call are not
vb@130
  2330
** reflected in subsequent calls to [sqlite3_errcode()] or
vb@130
  2331
** [sqlite3_errmsg()].
vb@130
  2332
*/
Edouard@491
  2333
SQLITE_API int SQLITE_STDCALL sqlite3_get_table(
vb@130
  2334
  sqlite3 *db,          /* An open database */
vb@130
  2335
  const char *zSql,     /* SQL to be evaluated */
vb@130
  2336
  char ***pazResult,    /* Results of the query */
vb@130
  2337
  int *pnRow,           /* Number of result rows written here */
vb@130
  2338
  int *pnColumn,        /* Number of result columns written here */
vb@130
  2339
  char **pzErrmsg       /* Error msg written here */
vb@130
  2340
);
Edouard@491
  2341
SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result);
vb@130
  2342
vb@130
  2343
/*
vb@130
  2344
** CAPI3REF: Formatted String Printing Functions
vb@130
  2345
**
vb@130
  2346
** These routines are work-alikes of the "printf()" family of functions
vb@130
  2347
** from the standard C library.
Edouard@491
  2348
** These routines understand most of the common K&R formatting options,
Edouard@491
  2349
** plus some additional non-standard formats, detailed below.
Edouard@491
  2350
** Note that some of the more obscure formatting options from recent
Edouard@491
  2351
** C-library standards are omitted from this implementation.
vb@130
  2352
**
vb@130
  2353
** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
vb@130
  2354
** results into memory obtained from [sqlite3_malloc()].
vb@130
  2355
** The strings returned by these two routines should be
vb@130
  2356
** released by [sqlite3_free()].  ^Both routines return a
vb@130
  2357
** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
vb@130
  2358
** memory to hold the resulting string.
vb@130
  2359
**
vb@130
  2360
** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
vb@130
  2361
** the standard C library.  The result is written into the
vb@130
  2362
** buffer supplied as the second parameter whose size is given by
vb@130
  2363
** the first parameter. Note that the order of the
vb@130
  2364
** first two parameters is reversed from snprintf().)^  This is an
vb@130
  2365
** historical accident that cannot be fixed without breaking
vb@130
  2366
** backwards compatibility.  ^(Note also that sqlite3_snprintf()
vb@130
  2367
** returns a pointer to its buffer instead of the number of
vb@130
  2368
** characters actually written into the buffer.)^  We admit that
vb@130
  2369
** the number of characters written would be a more useful return
vb@130
  2370
** value but we cannot change the implementation of sqlite3_snprintf()
vb@130
  2371
** now without breaking compatibility.
vb@130
  2372
**
vb@130
  2373
** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
vb@130
  2374
** guarantees that the buffer is always zero-terminated.  ^The first
vb@130
  2375
** parameter "n" is the total size of the buffer, including space for
vb@130
  2376
** the zero terminator.  So the longest string that can be completely
vb@130
  2377
** written will be n-1 characters.
vb@130
  2378
**
vb@130
  2379
** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
vb@130
  2380
**
vb@130
  2381
** These routines all implement some additional formatting
vb@130
  2382
** options that are useful for constructing SQL statements.
vb@130
  2383
** All of the usual printf() formatting options apply.  In addition, there
Edouard@491
  2384
** is are "%q", "%Q", "%w" and "%z" options.
vb@130
  2385
**
vb@130
  2386
** ^(The %q option works like %s in that it substitutes a nul-terminated
vb@130
  2387
** string from the argument list.  But %q also doubles every '\'' character.
vb@130
  2388
** %q is designed for use inside a string literal.)^  By doubling each '\''
vb@130
  2389
** character it escapes that character and allows it to be inserted into
vb@130
  2390
** the string.
vb@130
  2391
**
vb@130
  2392
** For example, assume the string variable zText contains text as follows:
vb@130
  2393
**
vb@130
  2394
** <blockquote><pre>
vb@130
  2395
**  char *zText = "It's a happy day!";
vb@130
  2396
** </pre></blockquote>
vb@130
  2397
**
vb@130
  2398
** One can use this text in an SQL statement as follows:
vb@130
  2399
**
vb@130
  2400
** <blockquote><pre>
vb@130
  2401
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
vb@130
  2402
**  sqlite3_exec(db, zSQL, 0, 0, 0);
vb@130
  2403
**  sqlite3_free(zSQL);
vb@130
  2404
** </pre></blockquote>
vb@130
  2405
**
vb@130
  2406
** Because the %q format string is used, the '\'' character in zText
vb@130
  2407
** is escaped and the SQL generated is as follows:
vb@130
  2408
**
vb@130
  2409
** <blockquote><pre>
vb@130
  2410
**  INSERT INTO table1 VALUES('It''s a happy day!')
vb@130
  2411
** </pre></blockquote>
vb@130
  2412
**
vb@130
  2413
** This is correct.  Had we used %s instead of %q, the generated SQL
vb@130
  2414
** would have looked like this:
vb@130
  2415
**
vb@130
  2416
** <blockquote><pre>
vb@130
  2417
**  INSERT INTO table1 VALUES('It's a happy day!');
vb@130
  2418
** </pre></blockquote>
vb@130
  2419
**
vb@130
  2420
** This second example is an SQL syntax error.  As a general rule you should
vb@130
  2421
** always use %q instead of %s when inserting text into a string literal.
vb@130
  2422
**
vb@130
  2423
** ^(The %Q option works like %q except it also adds single quotes around
vb@130
  2424
** the outside of the total string.  Additionally, if the parameter in the
vb@130
  2425
** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
vb@130
  2426
** single quotes).)^  So, for example, one could say:
vb@130
  2427
**
vb@130
  2428
** <blockquote><pre>
vb@130
  2429
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
vb@130
  2430
**  sqlite3_exec(db, zSQL, 0, 0, 0);
vb@130
  2431
**  sqlite3_free(zSQL);
vb@130
  2432
** </pre></blockquote>
vb@130
  2433
**
vb@130
  2434
** The code above will render a correct SQL statement in the zSQL
vb@130
  2435
** variable even if the zText variable is a NULL pointer.
vb@130
  2436
**
Edouard@491
  2437
** ^(The "%w" formatting option is like "%q" except that it expects to
Edouard@491
  2438
** be contained within double-quotes instead of single quotes, and it
Edouard@491
  2439
** escapes the double-quote character instead of the single-quote
Edouard@491
  2440
** character.)^  The "%w" formatting option is intended for safely inserting
Edouard@491
  2441
** table and column names into a constructed SQL statement.
Edouard@491
  2442
**
vb@130
  2443
** ^(The "%z" formatting option works like "%s" but with the
vb@130
  2444
** addition that after the string has been read and copied into
vb@130
  2445
** the result, [sqlite3_free()] is called on the input string.)^
vb@130
  2446
*/
Edouard@491
  2447
SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...);
Edouard@491
  2448
SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list);
Edouard@491
  2449
SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...);
Edouard@491
  2450
SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list);
vb@130
  2451
vb@130
  2452
/*
vb@130
  2453
** CAPI3REF: Memory Allocation Subsystem
vb@130
  2454
**
vb@130
  2455
** The SQLite core uses these three routines for all of its own
vb@130
  2456
** internal memory allocation needs. "Core" in the previous sentence
vb@130
  2457
** does not include operating-system specific VFS implementation.  The
vb@130
  2458
** Windows VFS uses native malloc() and free() for some operations.
vb@130
  2459
**
vb@130
  2460
** ^The sqlite3_malloc() routine returns a pointer to a block
vb@130
  2461
** of memory at least N bytes in length, where N is the parameter.
vb@130
  2462
** ^If sqlite3_malloc() is unable to obtain sufficient free
vb@130
  2463
** memory, it returns a NULL pointer.  ^If the parameter N to
vb@130
  2464
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
vb@130
  2465
** a NULL pointer.
vb@130
  2466
**
Edouard@491
  2467
** ^The sqlite3_malloc64(N) routine works just like
Edouard@491
  2468
** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
Edouard@491
  2469
** of a signed 32-bit integer.
Edouard@491
  2470
**
vb@130
  2471
** ^Calling sqlite3_free() with a pointer previously returned
vb@130
  2472
** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
vb@130
  2473
** that it might be reused.  ^The sqlite3_free() routine is
vb@130
  2474
** a no-op if is called with a NULL pointer.  Passing a NULL pointer
vb@130
  2475
** to sqlite3_free() is harmless.  After being freed, memory
vb@130
  2476
** should neither be read nor written.  Even reading previously freed
vb@130
  2477
** memory might result in a segmentation fault or other severe error.
vb@130
  2478
** Memory corruption, a segmentation fault, or other severe error
vb@130
  2479
** might result if sqlite3_free() is called with a non-NULL pointer that
vb@130
  2480
** was not obtained from sqlite3_malloc() or sqlite3_realloc().
vb@130
  2481
**
Edouard@491
  2482
** ^The sqlite3_realloc(X,N) interface attempts to resize a
Edouard@491
  2483
** prior memory allocation X to be at least N bytes.
Edouard@491
  2484
** ^If the X parameter to sqlite3_realloc(X,N)
vb@130
  2485
** is a NULL pointer then its behavior is identical to calling
Edouard@491
  2486
** sqlite3_malloc(N).
Edouard@491
  2487
** ^If the N parameter to sqlite3_realloc(X,N) is zero or
vb@130
  2488
** negative then the behavior is exactly the same as calling
Edouard@491
  2489
** sqlite3_free(X).
Edouard@491
  2490
** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
Edouard@491
  2491
** of at least N bytes in size or NULL if insufficient memory is available.
vb@130
  2492
** ^If M is the size of the prior allocation, then min(N,M) bytes
vb@130
  2493
** of the prior allocation are copied into the beginning of buffer returned
Edouard@491
  2494
** by sqlite3_realloc(X,N) and the prior allocation is freed.
Edouard@491
  2495
** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
Edouard@491
  2496
** prior allocation is not freed.
Edouard@491
  2497
**
Edouard@491
  2498
** ^The sqlite3_realloc64(X,N) interfaces works the same as
Edouard@491
  2499
** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
Edouard@491
  2500
** of a 32-bit signed integer.
Edouard@491
  2501
**
Edouard@491
  2502
** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
Edouard@491
  2503
** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
Edouard@491
  2504
** sqlite3_msize(X) returns the size of that memory allocation in bytes.
Edouard@491
  2505
** ^The value returned by sqlite3_msize(X) might be larger than the number
Edouard@491
  2506
** of bytes requested when X was allocated.  ^If X is a NULL pointer then
Edouard@491
  2507
** sqlite3_msize(X) returns zero.  If X points to something that is not
Edouard@491
  2508
** the beginning of memory allocation, or if it points to a formerly
Edouard@491
  2509
** valid memory allocation that has now been freed, then the behavior
Edouard@491
  2510
** of sqlite3_msize(X) is undefined and possibly harmful.
Edouard@491
  2511
**
Edouard@491
  2512
** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
Edouard@491
  2513
** sqlite3_malloc64(), and sqlite3_realloc64()
vb@130
  2514
** is always aligned to at least an 8 byte boundary, or to a
vb@130
  2515
** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
vb@130
  2516
** option is used.
vb@130
  2517
**
vb@130
  2518
** In SQLite version 3.5.0 and 3.5.1, it was possible to define
vb@130
  2519
** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
vb@130
  2520
** implementation of these routines to be omitted.  That capability
vb@130
  2521
** is no longer provided.  Only built-in memory allocators can be used.
vb@130
  2522
**
vb@130
  2523
** Prior to SQLite version 3.7.10, the Windows OS interface layer called
vb@130
  2524
** the system malloc() and free() directly when converting
vb@130
  2525
** filenames between the UTF-8 encoding used by SQLite
vb@130
  2526
** and whatever filename encoding is used by the particular Windows
vb@130
  2527
** installation.  Memory allocation errors were detected, but
vb@130
  2528
** they were reported back as [SQLITE_CANTOPEN] or
vb@130
  2529
** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
vb@130
  2530
**
vb@130
  2531
** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
vb@130
  2532
** must be either NULL or else pointers obtained from a prior
vb@130
  2533
** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
vb@130
  2534
** not yet been released.
vb@130
  2535
**
vb@130
  2536
** The application must not read or write any part of
vb@130
  2537
** a block of memory after it has been released using
vb@130
  2538
** [sqlite3_free()] or [sqlite3_realloc()].
vb@130
  2539
*/
Edouard@491
  2540
SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int);
Edouard@491
  2541
SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64);
Edouard@491
  2542
SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int);
Edouard@491
  2543
SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64);
Edouard@491
  2544
SQLITE_API void SQLITE_STDCALL sqlite3_free(void*);
Edouard@491
  2545
SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*);
vb@130
  2546
vb@130
  2547
/*
vb@130
  2548
** CAPI3REF: Memory Allocator Statistics
vb@130
  2549
**
vb@130
  2550
** SQLite provides these two interfaces for reporting on the status
vb@130
  2551
** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
vb@130
  2552
** routines, which form the built-in memory allocation subsystem.
vb@130
  2553
**
vb@130
  2554
** ^The [sqlite3_memory_used()] routine returns the number of bytes
vb@130
  2555
** of memory currently outstanding (malloced but not freed).
vb@130
  2556
** ^The [sqlite3_memory_highwater()] routine returns the maximum
vb@130
  2557
** value of [sqlite3_memory_used()] since the high-water mark
vb@130
  2558
** was last reset.  ^The values returned by [sqlite3_memory_used()] and
vb@130
  2559
** [sqlite3_memory_highwater()] include any overhead
vb@130
  2560
** added by SQLite in its implementation of [sqlite3_malloc()],
vb@130
  2561
** but not overhead added by the any underlying system library
vb@130
  2562
** routines that [sqlite3_malloc()] may call.
vb@130
  2563
**
vb@130
  2564
** ^The memory high-water mark is reset to the current value of
vb@130
  2565
** [sqlite3_memory_used()] if and only if the parameter to
vb@130
  2566
** [sqlite3_memory_highwater()] is true.  ^The value returned
vb@130
  2567
** by [sqlite3_memory_highwater(1)] is the high-water mark
vb@130
  2568
** prior to the reset.
vb@130
  2569
*/
Edouard@491
  2570
SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void);
Edouard@491
  2571
SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag);
vb@130
  2572
vb@130
  2573
/*
vb@130
  2574
** CAPI3REF: Pseudo-Random Number Generator
vb@130
  2575
**
vb@130
  2576
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
vb@130
  2577
** select random [ROWID | ROWIDs] when inserting new records into a table that
vb@130
  2578
** already uses the largest possible [ROWID].  The PRNG is also used for
vb@130
  2579
** the build-in random() and randomblob() SQL functions.  This interface allows
vb@130
  2580
** applications to access the same PRNG for other purposes.
vb@130
  2581
**
vb@130
  2582
** ^A call to this routine stores N bytes of randomness into buffer P.
Edouard@491
  2583
** ^The P parameter can be a NULL pointer.
vb@130
  2584
**
vb@130
  2585
** ^If this routine has not been previously called or if the previous
Edouard@491
  2586
** call had N less than one or a NULL pointer for P, then the PRNG is
Edouard@491
  2587
** seeded using randomness obtained from the xRandomness method of
Edouard@491
  2588
** the default [sqlite3_vfs] object.
Edouard@491
  2589
** ^If the previous call to this routine had an N of 1 or more and a
Edouard@491
  2590
** non-NULL P then the pseudo-randomness is generated
vb@130
  2591
** internally and without recourse to the [sqlite3_vfs] xRandomness
vb@130
  2592
** method.
vb@130
  2593
*/
Edouard@491
  2594
SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P);
vb@130
  2595
vb@130
  2596
/*
vb@130
  2597
** CAPI3REF: Compile-Time Authorization Callbacks
Edouard@491
  2598
** METHOD: sqlite3
vb@130
  2599
**
vb@130
  2600
** ^This routine registers an authorizer callback with a particular
vb@130
  2601
** [database connection], supplied in the first argument.
vb@130
  2602
** ^The authorizer callback is invoked as SQL statements are being compiled
vb@130
  2603
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
vb@130
  2604
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
vb@130
  2605
** points during the compilation process, as logic is being created
vb@130
  2606
** to perform various actions, the authorizer callback is invoked to
vb@130
  2607
** see if those actions are allowed.  ^The authorizer callback should
vb@130
  2608
** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
vb@130
  2609
** specific action but allow the SQL statement to continue to be
vb@130
  2610
** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
vb@130
  2611
** rejected with an error.  ^If the authorizer callback returns
vb@130
  2612
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
vb@130
  2613
** then the [sqlite3_prepare_v2()] or equivalent call that triggered
vb@130
  2614
** the authorizer will fail with an error message.
vb@130
  2615
**
vb@130
  2616
** When the callback returns [SQLITE_OK], that means the operation
vb@130
  2617
** requested is ok.  ^When the callback returns [SQLITE_DENY], the
vb@130
  2618
** [sqlite3_prepare_v2()] or equivalent call that triggered the
vb@130
  2619
** authorizer will fail with an error message explaining that
vb@130
  2620
** access is denied. 
vb@130
  2621
**
vb@130
  2622
** ^The first parameter to the authorizer callback is a copy of the third
vb@130
  2623
** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
vb@130
  2624
** to the callback is an integer [SQLITE_COPY | action code] that specifies
vb@130
  2625
** the particular action to be authorized. ^The third through sixth parameters
vb@130
  2626
** to the callback are zero-terminated strings that contain additional
vb@130
  2627
** details about the action to be authorized.
vb@130
  2628
**
vb@130
  2629
** ^If the action code is [SQLITE_READ]
vb@130
  2630
** and the callback returns [SQLITE_IGNORE] then the
vb@130
  2631
** [prepared statement] statement is constructed to substitute
vb@130
  2632
** a NULL value in place of the table column that would have
vb@130
  2633
** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
vb@130
  2634
** return can be used to deny an untrusted user access to individual
vb@130
  2635
** columns of a table.
vb@130
  2636
** ^If the action code is [SQLITE_DELETE] and the callback returns
vb@130
  2637
** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
vb@130
  2638
** [truncate optimization] is disabled and all rows are deleted individually.
vb@130
  2639
**
vb@130
  2640
** An authorizer is used when [sqlite3_prepare | preparing]
vb@130
  2641
** SQL statements from an untrusted source, to ensure that the SQL statements
vb@130
  2642
** do not try to access data they are not allowed to see, or that they do not
vb@130
  2643
** try to execute malicious statements that damage the database.  For
vb@130
  2644
** example, an application may allow a user to enter arbitrary
vb@130
  2645
** SQL queries for evaluation by a database.  But the application does
vb@130
  2646
** not want the user to be able to make arbitrary changes to the
vb@130
  2647
** database.  An authorizer could then be put in place while the
vb@130
  2648
** user-entered SQL is being [sqlite3_prepare | prepared] that
vb@130
  2649
** disallows everything except [SELECT] statements.
vb@130
  2650
**
vb@130
  2651
** Applications that need to process SQL from untrusted sources
vb@130
  2652
** might also consider lowering resource limits using [sqlite3_limit()]
vb@130
  2653
** and limiting database size using the [max_page_count] [PRAGMA]
vb@130
  2654
** in addition to using an authorizer.
vb@130
  2655
**
vb@130
  2656
** ^(Only a single authorizer can be in place on a database connection
vb@130
  2657
** at a time.  Each call to sqlite3_set_authorizer overrides the
vb@130
  2658
** previous call.)^  ^Disable the authorizer by installing a NULL callback.
vb@130
  2659
** The authorizer is disabled by default.
vb@130
  2660
**
vb@130
  2661
** The authorizer callback must not do anything that will modify
vb@130
  2662
** the database connection that invoked the authorizer callback.
vb@130
  2663
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
vb@130
  2664
** database connections for the meaning of "modify" in this paragraph.
vb@130
  2665
**
vb@130
  2666
** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
vb@130
  2667
** statement might be re-prepared during [sqlite3_step()] due to a 
vb@130
  2668
** schema change.  Hence, the application should ensure that the
vb@130
  2669
** correct authorizer callback remains in place during the [sqlite3_step()].
vb@130
  2670
**
vb@130
  2671
** ^Note that the authorizer callback is invoked only during
vb@130
  2672
** [sqlite3_prepare()] or its variants.  Authorization is not
vb@130
  2673
** performed during statement evaluation in [sqlite3_step()], unless
vb@130
  2674
** as stated in the previous paragraph, sqlite3_step() invokes
vb@130
  2675
** sqlite3_prepare_v2() to reprepare a statement after a schema change.
vb@130
  2676
*/
Edouard@491
  2677
SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer(
vb@130
  2678
  sqlite3*,
vb@130
  2679
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
vb@130
  2680
  void *pUserData
vb@130
  2681
);
vb@130
  2682
vb@130
  2683
/*
vb@130
  2684
** CAPI3REF: Authorizer Return Codes
vb@130
  2685
**
vb@130
  2686
** The [sqlite3_set_authorizer | authorizer callback function] must
vb@130
  2687
** return either [SQLITE_OK] or one of these two constants in order
vb@130
  2688
** to signal SQLite whether or not the action is permitted.  See the
vb@130
  2689
** [sqlite3_set_authorizer | authorizer documentation] for additional
vb@130
  2690
** information.
vb@130
  2691
**
vb@130
  2692
** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
vb@130
  2693
** returned from the [sqlite3_vtab_on_conflict()] interface.
vb@130
  2694
*/
vb@130
  2695
#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
vb@130
  2696
#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */