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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 suppose 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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** Add the ability to override 'extern'
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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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/*
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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 support 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        "3.8.3.1"
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#define SQLITE_VERSION_NUMBER 3008003
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#define SQLITE_SOURCE_ID      "2014-02-11 14:52:19 ea3317a4803d71d88183b29f1d3086f46d68a00e"
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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 insure 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 *sqlite3_libversion(void);
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SQLITE_API const char *sqlite3_sourceid(void);
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SQLITE_API int sqlite3_libversion_number(void);
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/*
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** CAPI3REF: Run-Time Library Compilation Options Diagnostics
151
**
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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].
170
*/
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#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
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SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
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SQLITE_API const char *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.
182
**
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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, 
187
** 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.
198
**
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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_MUTEX].  ^(The return value of the
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** sqlite3_threadsafe() function shows only the compile-time setting of
206
** thread safety, not any run-time changes to that setting made by
207
** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
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** is unchanged by calls to sqlite3_config().)^
209
**
210
** See the [threading mode] documentation for additional information.
211
*/
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SQLITE_API int 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
220
** 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.
227
*/
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typedef struct sqlite3 sqlite3;
229

    
230
/*
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** CAPI3REF: 64-Bit Integer Types
232
** KEYWORDS: sqlite_int64 sqlite_uint64
233
**
234
** Because there is no cross-platform way to specify 64-bit integer types
235
** SQLite includes typedefs for 64-bit signed and unsigned integers.
236
**
237
** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
238
** The sqlite_int64 and sqlite_uint64 types are supported for backwards
239
** compatibility only.
240
**
241
** ^The sqlite3_int64 and sqlite_int64 types can store integer values
242
** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
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** sqlite3_uint64 and sqlite_uint64 types can store integer values 
244
** between 0 and +18446744073709551615 inclusive.
245
*/
246
#ifdef SQLITE_INT64_TYPE
247
  typedef SQLITE_INT64_TYPE sqlite_int64;
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  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
249
#elif defined(_MSC_VER) || defined(__BORLANDC__)
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  typedef __int64 sqlite_int64;
251
  typedef unsigned __int64 sqlite_uint64;
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#else
253
  typedef long long int sqlite_int64;
254
  typedef unsigned long long int sqlite_uint64;
255
#endif
256
typedef sqlite_int64 sqlite3_int64;
257
typedef sqlite_uint64 sqlite3_uint64;
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259
/*
260
** If compiling for a processor that lacks floating point support,
261
** substitute integer for floating-point.
262
*/
263
#ifdef SQLITE_OMIT_FLOATING_POINT
264
# define double sqlite3_int64
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#endif
266

    
267
/*
268
** CAPI3REF: Closing A Database Connection
269
**
270
** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
271
** for the [sqlite3] object.
272
** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if
273
** the [sqlite3] object is successfully destroyed and all associated
274
** resources are deallocated.
275
**
276
** ^If the database connection is associated with unfinalized prepared
277
** statements or unfinished sqlite3_backup objects then sqlite3_close()
278
** will leave the database connection open and return [SQLITE_BUSY].
279
** ^If sqlite3_close_v2() is called with unfinalized prepared statements
280
** and unfinished sqlite3_backups, then the database connection becomes
281
** an unusable "zombie" which will automatically be deallocated when the
282
** last prepared statement is finalized or the last sqlite3_backup is
283
** finished.  The sqlite3_close_v2() interface is intended for use with
284
** host languages that are garbage collected, and where the order in which
285
** destructors are called is arbitrary.
286
**
287
** Applications should [sqlite3_finalize | finalize] all [prepared statements],
288
** [sqlite3_blob_close | close] all [BLOB handles], and 
289
** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
290
** with the [sqlite3] object prior to attempting to close the object.  ^If
291
** sqlite3_close_v2() is called on a [database connection] that still has
292
** outstanding [prepared statements], [BLOB handles], and/or
293
** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation
294
** of resources is deferred until all [prepared statements], [BLOB handles],
295
** and [sqlite3_backup] objects are also destroyed.
296
**
297
** ^If an [sqlite3] object is destroyed while a transaction is open,
298
** the transaction is automatically rolled back.
299
**
300
** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
301
** must be either a NULL
302
** pointer or an [sqlite3] object pointer obtained
303
** from [sqlite3_open()], [sqlite3_open16()], or
304
** [sqlite3_open_v2()], and not previously closed.
305
** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
306
** argument is a harmless no-op.
307
*/
308
SQLITE_API int sqlite3_close(sqlite3*);
309
SQLITE_API int sqlite3_close_v2(sqlite3*);
310

    
311
/*
312
** The type for a callback function.
313
** This is legacy and deprecated.  It is included for historical
314
** compatibility and is not documented.
315
*/
316
typedef int (*sqlite3_callback)(void*,int,char**, char**);
317

    
318
/*
319
** CAPI3REF: One-Step Query Execution Interface
320
**
321
** The sqlite3_exec() interface is a convenience wrapper around
322
** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
323
** that allows an application to run multiple statements of SQL
324
** without having to use a lot of C code. 
325
**
326
** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
327
** semicolon-separate SQL statements passed into its 2nd argument,
328
** in the context of the [database connection] passed in as its 1st
329
** argument.  ^If the callback function of the 3rd argument to
330
** sqlite3_exec() is not NULL, then it is invoked for each result row
331
** coming out of the evaluated SQL statements.  ^The 4th argument to
332
** sqlite3_exec() is relayed through to the 1st argument of each
333
** callback invocation.  ^If the callback pointer to sqlite3_exec()
334
** is NULL, then no callback is ever invoked and result rows are
335
** ignored.
336
**
337
** ^If an error occurs while evaluating the SQL statements passed into
338
** sqlite3_exec(), then execution of the current statement stops and
339
** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
340
** is not NULL then any error message is written into memory obtained
341
** from [sqlite3_malloc()] and passed back through the 5th parameter.
342
** To avoid memory leaks, the application should invoke [sqlite3_free()]
343
** on error message strings returned through the 5th parameter of
344
** of sqlite3_exec() after the error message string is no longer needed.
345
** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
346
** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
347
** NULL before returning.
348
**
349
** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
350
** routine returns SQLITE_ABORT without invoking the callback again and
351
** without running any subsequent SQL statements.
352
**
353
** ^The 2nd argument to the sqlite3_exec() callback function is the
354
** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
355
** callback is an array of pointers to strings obtained as if from
356
** [sqlite3_column_text()], one for each column.  ^If an element of a
357
** result row is NULL then the corresponding string pointer for the
358
** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
359
** sqlite3_exec() callback is an array of pointers to strings where each
360
** entry represents the name of corresponding result column as obtained
361
** from [sqlite3_column_name()].
362
**
363
** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
364
** to an empty string, or a pointer that contains only whitespace and/or 
365
** SQL comments, then no SQL statements are evaluated and the database
366
** is not changed.
367
**
368
** Restrictions:
369
**
370
** <ul>
371
** <li> The application must insure that the 1st parameter to sqlite3_exec()
372
**      is a valid and open [database connection].
373
** <li> The application must not close the [database connection] specified by
374
**      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
375
** <li> The application must not modify the SQL statement text passed into
376
**      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
377
** </ul>
378
*/
379
SQLITE_API int sqlite3_exec(
380
  sqlite3*,                                  /* An open database */
381
  const char *sql,                           /* SQL to be evaluated */
382
  int (*callback)(void*,int,char**,char**),  /* Callback function */
383
  void *,                                    /* 1st argument to callback */
384
  char **errmsg                              /* Error msg written here */
385
);
386

    
387
/*
388
** CAPI3REF: Result Codes
389
** KEYWORDS: SQLITE_OK {error code} {error codes}
390
** KEYWORDS: {result code} {result codes}
391
**
392
** Many SQLite functions return an integer result code from the set shown
393
** here in order to indicate success or failure.
394
**
395
** New error codes may be added in future versions of SQLite.
396
**
397
** See also: [SQLITE_IOERR_READ | extended result codes],
398
** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
399
*/
400
#define SQLITE_OK           0   /* Successful result */
401
/* beginning-of-error-codes */
402
#define SQLITE_ERROR        1   /* SQL error or missing database */
403
#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
404
#define SQLITE_PERM         3   /* Access permission denied */
405
#define SQLITE_ABORT        4   /* Callback routine requested an abort */
406
#define SQLITE_BUSY         5   /* The database file is locked */
407
#define SQLITE_LOCKED       6   /* A table in the database is locked */
408
#define SQLITE_NOMEM        7   /* A malloc() failed */
409
#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
410
#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
411
#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
412
#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
413
#define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
414
#define SQLITE_FULL        13   /* Insertion failed because database is full */
415
#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
416
#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
417
#define SQLITE_EMPTY       16   /* Database is empty */
418
#define SQLITE_SCHEMA      17   /* The database schema changed */
419
#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
420
#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
421
#define SQLITE_MISMATCH    20   /* Data type mismatch */
422
#define SQLITE_MISUSE      21   /* Library used incorrectly */
423
#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
424
#define SQLITE_AUTH        23   /* Authorization denied */
425
#define SQLITE_FORMAT      24   /* Auxiliary database format error */
426
#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
427
#define SQLITE_NOTADB      26   /* File opened that is not a database file */
428
#define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
429
#define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
430
#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
431
#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
432
/* end-of-error-codes */
433

    
434
/*
435
** CAPI3REF: Extended Result Codes
436
** KEYWORDS: {extended error code} {extended error codes}
437
** KEYWORDS: {extended result code} {extended result codes}
438
**
439
** In its default configuration, SQLite API routines return one of 26 integer
440
** [SQLITE_OK | result codes].  However, experience has shown that many of
441
** these result codes are too coarse-grained.  They do not provide as
442
** much information about problems as programmers might like.  In an effort to
443
** address this, newer versions of SQLite (version 3.3.8 and later) include
444
** support for additional result codes that provide more detailed information
445
** about errors. The extended result codes are enabled or disabled
446
** on a per database connection basis using the
447
** [sqlite3_extended_result_codes()] API.
448
**
449
** Some of the available extended result codes are listed here.
450
** One may expect the number of extended result codes will increase
451
** over time.  Software that uses extended result codes should expect
452
** to see new result codes in future releases of SQLite.
453
**
454
** The SQLITE_OK result code will never be extended.  It will always
455
** be exactly zero.
456
*/
457
#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
458
#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
459
#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
460
#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
461
#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
462
#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
463
#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
464
#define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
465
#define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
466
#define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
467
#define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
468
#define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
469
#define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
470
#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
471
#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
472
#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
473
#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
474
#define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
475
#define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
476
#define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
477
#define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
478
#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
479
#define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
480
#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
481
#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
482
#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
483
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
484
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
485
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
486
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
487
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
488
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
489
#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
490
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
491
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
492
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
493
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
494
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
495
#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
496
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
497
#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
498
#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
499
#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
500
#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
501
#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
502
#define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))
503
#define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))
504
#define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
505
#define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))
506
#define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
507
#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
508
#define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
509

    
510
/*
511
** CAPI3REF: Flags For File Open Operations
512
**
513
** These bit values are intended for use in the
514
** 3rd parameter to the [sqlite3_open_v2()] interface and
515
** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
516
*/
517
#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
518
#define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
519
#define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
520
#define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
521
#define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
522
#define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
523
#define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
524
#define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
525
#define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
526
#define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
527
#define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
528
#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
529
#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
530
#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
531
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
532
#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
533
#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
534
#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
535
#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
536
#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
537

    
538
/* Reserved:                         0x00F00000 */
539

    
540
/*
541
** CAPI3REF: Device Characteristics
542
**
543
** The xDeviceCharacteristics method of the [sqlite3_io_methods]
544
** object returns an integer which is a vector of these
545
** bit values expressing I/O characteristics of the mass storage
546
** device that holds the file that the [sqlite3_io_methods]
547
** refers to.
548
**
549
** The SQLITE_IOCAP_ATOMIC property means that all writes of
550
** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
551
** mean that writes of blocks that are nnn bytes in size and
552
** are aligned to an address which is an integer multiple of
553
** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
554
** that when data is appended to a file, the data is appended
555
** first then the size of the file is extended, never the other
556
** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
557
** information is written to disk in the same order as calls
558
** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
559
** after reboot following a crash or power loss, the only bytes in a
560
** file that were written at the application level might have changed
561
** and that adjacent bytes, even bytes within the same sector are
562
** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
563
** flag indicate that a file cannot be deleted when open.
564
*/
565
#define SQLITE_IOCAP_ATOMIC                 0x00000001
566
#define SQLITE_IOCAP_ATOMIC512              0x00000002
567
#define SQLITE_IOCAP_ATOMIC1K               0x00000004
568
#define SQLITE_IOCAP_ATOMIC2K               0x00000008
569
#define SQLITE_IOCAP_ATOMIC4K               0x00000010
570
#define SQLITE_IOCAP_ATOMIC8K               0x00000020
571
#define SQLITE_IOCAP_ATOMIC16K              0x00000040
572
#define SQLITE_IOCAP_ATOMIC32K              0x00000080
573
#define SQLITE_IOCAP_ATOMIC64K              0x00000100
574
#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
575
#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
576
#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
577
#define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
578

    
579
/*
580
** CAPI3REF: File Locking Levels
581
**
582
** SQLite uses one of these integer values as the second
583
** argument to calls it makes to the xLock() and xUnlock() methods
584
** of an [sqlite3_io_methods] object.
585
*/
586
#define SQLITE_LOCK_NONE          0
587
#define SQLITE_LOCK_SHARED        1
588
#define SQLITE_LOCK_RESERVED      2
589
#define SQLITE_LOCK_PENDING       3
590
#define SQLITE_LOCK_EXCLUSIVE     4
591

    
592
/*
593
** CAPI3REF: Synchronization Type Flags
594
**
595
** When SQLite invokes the xSync() method of an
596
** [sqlite3_io_methods] object it uses a combination of
597
** these integer values as the second argument.
598
**
599
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
600
** sync operation only needs to flush data to mass storage.  Inode
601
** information need not be flushed. If the lower four bits of the flag
602
** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
603
** If the lower four bits equal SQLITE_SYNC_FULL, that means
604
** to use Mac OS X style fullsync instead of fsync().
605
**
606
** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
607
** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
608
** settings.  The [synchronous pragma] determines when calls to the
609
** xSync VFS method occur and applies uniformly across all platforms.
610
** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
611
** energetic or rigorous or forceful the sync operations are and
612
** only make a difference on Mac OSX for the default SQLite code.
613
** (Third-party VFS implementations might also make the distinction
614
** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
615
** operating systems natively supported by SQLite, only Mac OSX
616
** cares about the difference.)
617
*/
618
#define SQLITE_SYNC_NORMAL        0x00002
619
#define SQLITE_SYNC_FULL          0x00003
620
#define SQLITE_SYNC_DATAONLY      0x00010
621

    
622
/*
623
** CAPI3REF: OS Interface Open File Handle
624
**
625
** An [sqlite3_file] object represents an open file in the 
626
** [sqlite3_vfs | OS interface layer].  Individual OS interface
627
** implementations will
628
** want to subclass this object by appending additional fields
629
** for their own use.  The pMethods entry is a pointer to an
630
** [sqlite3_io_methods] object that defines methods for performing
631
** I/O operations on the open file.
632
*/
633
typedef struct sqlite3_file sqlite3_file;
634
struct sqlite3_file {
635
  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
636
};
637

    
638
/*
639
** CAPI3REF: OS Interface File Virtual Methods Object
640
**
641
** Every file opened by the [sqlite3_vfs.xOpen] method populates an
642
** [sqlite3_file] object (or, more commonly, a subclass of the
643
** [sqlite3_file] object) with a pointer to an instance of this object.
644
** This object defines the methods used to perform various operations
645
** against the open file represented by the [sqlite3_file] object.
646
**
647
** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 
648
** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
649
** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
650
** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
651
** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
652
** to NULL.
653
**
654
** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
655
** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
656
** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
657
** flag may be ORed in to indicate that only the data of the file
658
** and not its inode needs to be synced.
659
**
660
** The integer values to xLock() and xUnlock() are one of
661
** <ul>
662
** <li> [SQLITE_LOCK_NONE],
663
** <li> [SQLITE_LOCK_SHARED],
664
** <li> [SQLITE_LOCK_RESERVED],
665
** <li> [SQLITE_LOCK_PENDING], or
666
** <li> [SQLITE_LOCK_EXCLUSIVE].
667
** </ul>
668
** xLock() increases the lock. xUnlock() decreases the lock.
669
** The xCheckReservedLock() method checks whether any database connection,
670
** either in this process or in some other process, is holding a RESERVED,
671
** PENDING, or EXCLUSIVE lock on the file.  It returns true
672
** if such a lock exists and false otherwise.
673
**
674
** The xFileControl() method is a generic interface that allows custom
675
** VFS implementations to directly control an open file using the
676
** [sqlite3_file_control()] interface.  The second "op" argument is an
677
** integer opcode.  The third argument is a generic pointer intended to
678
** point to a structure that may contain arguments or space in which to
679
** write return values.  Potential uses for xFileControl() might be
680
** functions to enable blocking locks with timeouts, to change the
681
** locking strategy (for example to use dot-file locks), to inquire
682
** about the status of a lock, or to break stale locks.  The SQLite
683
** core reserves all opcodes less than 100 for its own use.
684
** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
685
** Applications that define a custom xFileControl method should use opcodes
686
** greater than 100 to avoid conflicts.  VFS implementations should
687
** return [SQLITE_NOTFOUND] for file control opcodes that they do not
688
** recognize.
689
**
690
** The xSectorSize() method returns the sector size of the
691
** device that underlies the file.  The sector size is the
692
** minimum write that can be performed without disturbing
693
** other bytes in the file.  The xDeviceCharacteristics()
694
** method returns a bit vector describing behaviors of the
695
** underlying device:
696
**
697
** <ul>
698
** <li> [SQLITE_IOCAP_ATOMIC]
699
** <li> [SQLITE_IOCAP_ATOMIC512]
700
** <li> [SQLITE_IOCAP_ATOMIC1K]
701
** <li> [SQLITE_IOCAP_ATOMIC2K]
702
** <li> [SQLITE_IOCAP_ATOMIC4K]
703
** <li> [SQLITE_IOCAP_ATOMIC8K]
704
** <li> [SQLITE_IOCAP_ATOMIC16K]
705
** <li> [SQLITE_IOCAP_ATOMIC32K]
706
** <li> [SQLITE_IOCAP_ATOMIC64K]
707
** <li> [SQLITE_IOCAP_SAFE_APPEND]
708
** <li> [SQLITE_IOCAP_SEQUENTIAL]
709
** </ul>
710
**
711
** The SQLITE_IOCAP_ATOMIC property means that all writes of
712
** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
713
** mean that writes of blocks that are nnn bytes in size and
714
** are aligned to an address which is an integer multiple of
715
** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
716
** that when data is appended to a file, the data is appended
717
** first then the size of the file is extended, never the other
718
** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
719
** information is written to disk in the same order as calls
720
** to xWrite().
721
**
722
** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
723
** in the unread portions of the buffer with zeros.  A VFS that
724
** fails to zero-fill short reads might seem to work.  However,
725
** failure to zero-fill short reads will eventually lead to
726
** database corruption.
727
*/
728
typedef struct sqlite3_io_methods sqlite3_io_methods;
729
struct sqlite3_io_methods {
730
  int iVersion;
731
  int (*xClose)(sqlite3_file*);
732
  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
733
  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
734
  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
735
  int (*xSync)(sqlite3_file*, int flags);
736
  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
737
  int (*xLock)(sqlite3_file*, int);
738
  int (*xUnlock)(sqlite3_file*, int);
739
  int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
740
  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
741
  int (*xSectorSize)(sqlite3_file*);
742
  int (*xDeviceCharacteristics)(sqlite3_file*);
743
  /* Methods above are valid for version 1 */
744
  int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
745
  int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
746
  void (*xShmBarrier)(sqlite3_file*);
747
  int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
748
  /* Methods above are valid for version 2 */
749
  int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
750
  int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
751
  /* Methods above are valid for version 3 */
752
  /* Additional methods may be added in future releases */
753
};
754

    
755
/*
756
** CAPI3REF: Standard File Control Opcodes
757
**
758
** These integer constants are opcodes for the xFileControl method
759
** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
760
** interface.
761
**
762
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
763
** opcode causes the xFileControl method to write the current state of
764
** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
765
** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
766
** into an integer that the pArg argument points to. This capability
767
** is used during testing and only needs to be supported when SQLITE_TEST
768
** is defined.
769
** <ul>
770
** <li>[[SQLITE_FCNTL_SIZE_HINT]]
771
** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
772
** layer a hint of how large the database file will grow to be during the
773
** current transaction.  This hint is not guaranteed to be accurate but it
774
** is often close.  The underlying VFS might choose to preallocate database
775
** file space based on this hint in order to help writes to the database
776
** file run faster.
777
**
778
** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
779
** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
780
** extends and truncates the database file in chunks of a size specified
781
** by the user. The fourth argument to [sqlite3_file_control()] should 
782
** point to an integer (type int) containing the new chunk-size to use
783
** for the nominated database. Allocating database file space in large
784
** chunks (say 1MB at a time), may reduce file-system fragmentation and
785
** improve performance on some systems.
786
**
787
** <li>[[SQLITE_FCNTL_FILE_POINTER]]
788
** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
789
** to the [sqlite3_file] object associated with a particular database
790
** connection.  See the [sqlite3_file_control()] documentation for
791
** additional information.
792
**
793
** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
794
** No longer in use.
795
**
796
** <li>[[SQLITE_FCNTL_SYNC]]
797
** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
798
** sent to the VFS immediately before the xSync method is invoked on a
799
** database file descriptor. Or, if the xSync method is not invoked 
800
** because the user has configured SQLite with 
801
** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 
802
** of the xSync method. In most cases, the pointer argument passed with
803
** this file-control is NULL. However, if the database file is being synced
804
** as part of a multi-database commit, the argument points to a nul-terminated
805
** string containing the transactions master-journal file name. VFSes that 
806
** do not need this signal should silently ignore this opcode. Applications 
807
** should not call [sqlite3_file_control()] with this opcode as doing so may 
808
** disrupt the operation of the specialized VFSes that do require it.  
809
**
810
** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
811
** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
812
** and sent to the VFS after a transaction has been committed immediately
813
** but before the database is unlocked. VFSes that do not need this signal
814
** should silently ignore this opcode. Applications should not call
815
** [sqlite3_file_control()] with this opcode as doing so may disrupt the 
816
** operation of the specialized VFSes that do require it.  
817
**
818
** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
819
** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
820
** retry counts and intervals for certain disk I/O operations for the
821
** windows [VFS] in order to provide robustness in the presence of
822
** anti-virus programs.  By default, the windows VFS will retry file read,
823
** file write, and file delete operations up to 10 times, with a delay
824
** of 25 milliseconds before the first retry and with the delay increasing
825
** by an additional 25 milliseconds with each subsequent retry.  This
826
** opcode allows these two values (10 retries and 25 milliseconds of delay)
827
** to be adjusted.  The values are changed for all database connections
828
** within the same process.  The argument is a pointer to an array of two
829
** integers where the first integer i the new retry count and the second
830
** integer is the delay.  If either integer is negative, then the setting
831
** is not changed but instead the prior value of that setting is written
832
** into the array entry, allowing the current retry settings to be
833
** interrogated.  The zDbName parameter is ignored.
834
**
835
** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
836
** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
837
** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
838
** write ahead log and shared memory files used for transaction control
839
** are automatically deleted when the latest connection to the database
840
** closes.  Setting persistent WAL mode causes those files to persist after
841
** close.  Persisting the files is useful when other processes that do not
842
** have write permission on the directory containing the database file want
843
** to read the database file, as the WAL and shared memory files must exist
844
** in order for the database to be readable.  The fourth parameter to
845
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
846
** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
847
** WAL mode.  If the integer is -1, then it is overwritten with the current
848
** WAL persistence setting.
849
**
850
** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
851
** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
852
** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
853
** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
854
** xDeviceCharacteristics methods. The fourth parameter to
855
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
856
** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
857
** mode.  If the integer is -1, then it is overwritten with the current
858
** zero-damage mode setting.
859
**
860
** <li>[[SQLITE_FCNTL_OVERWRITE]]
861
** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
862
** a write transaction to indicate that, unless it is rolled back for some
863
** reason, the entire database file will be overwritten by the current 
864
** transaction. This is used by VACUUM operations.
865
**
866
** <li>[[SQLITE_FCNTL_VFSNAME]]
867
** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
868
** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
869
** final bottom-level VFS are written into memory obtained from 
870
** [sqlite3_malloc()] and the result is stored in the char* variable
871
** that the fourth parameter of [sqlite3_file_control()] points to.
872
** The caller is responsible for freeing the memory when done.  As with
873
** all file-control actions, there is no guarantee that this will actually
874
** do anything.  Callers should initialize the char* variable to a NULL
875
** pointer in case this file-control is not implemented.  This file-control
876
** is intended for diagnostic use only.
877
**
878
** <li>[[SQLITE_FCNTL_PRAGMA]]
879
** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 
880
** file control is sent to the open [sqlite3_file] object corresponding
881
** to the database file to which the pragma statement refers. ^The argument
882
** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
883
** pointers to strings (char**) in which the second element of the array
884
** is the name of the pragma and the third element is the argument to the
885
** pragma or NULL if the pragma has no argument.  ^The handler for an
886
** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
887
** of the char** argument point to a string obtained from [sqlite3_mprintf()]
888
** or the equivalent and that string will become the result of the pragma or
889
** the error message if the pragma fails. ^If the
890
** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 
891
** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
892
** file control returns [SQLITE_OK], then the parser assumes that the
893
** VFS has handled the PRAGMA itself and the parser generates a no-op
894
** prepared statement.  ^If the [SQLITE_FCNTL_PRAGMA] file control returns
895
** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
896
** that the VFS encountered an error while handling the [PRAGMA] and the
897
** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
898
** file control occurs at the beginning of pragma statement analysis and so
899
** it is able to override built-in [PRAGMA] statements.
900
**
901
** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
902
** ^The [SQLITE_FCNTL_BUSYHANDLER]
903
** file-control may be invoked by SQLite on the database file handle
904
** shortly after it is opened in order to provide a custom VFS with access
905
** to the connections busy-handler callback. The argument is of type (void **)
906
** - an array of two (void *) values. The first (void *) actually points
907
** to a function of type (int (*)(void *)). In order to invoke the connections
908
** busy-handler, this function should be invoked with the second (void *) in
909
** the array as the only argument. If it returns non-zero, then the operation
910
** should be retried. If it returns zero, the custom VFS should abandon the
911
** current operation.
912
**
913
** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
914
** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
915
** to have SQLite generate a
916
** temporary filename using the same algorithm that is followed to generate
917
** temporary filenames for TEMP tables and other internal uses.  The
918
** argument should be a char** which will be filled with the filename
919
** written into memory obtained from [sqlite3_malloc()].  The caller should
920
** invoke [sqlite3_free()] on the result to avoid a memory leak.
921
**
922
** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
923
** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
924
** maximum number of bytes that will be used for memory-mapped I/O.
925
** The argument is a pointer to a value of type sqlite3_int64 that
926
** is an advisory maximum number of bytes in the file to memory map.  The
927
** pointer is overwritten with the old value.  The limit is not changed if
928
** the value originally pointed to is negative, and so the current limit 
929
** can be queried by passing in a pointer to a negative number.  This
930
** file-control is used internally to implement [PRAGMA mmap_size].
931
**
932
** <li>[[SQLITE_FCNTL_TRACE]]
933
** The [SQLITE_FCNTL_TRACE] file control provides advisory information
934
** to the VFS about what the higher layers of the SQLite stack are doing.
935
** This file control is used by some VFS activity tracing [shims].
936
** The argument is a zero-terminated string.  Higher layers in the
937
** SQLite stack may generate instances of this file control if
938
** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
939
**
940
** <li>[[SQLITE_FCNTL_HAS_MOVED]]
941
** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
942
** pointer to an integer and it writes a boolean into that integer depending
943
** on whether or not the file has been renamed, moved, or deleted since it
944
** was first opened.
945
**
946
** </ul>
947
*/
948
#define SQLITE_FCNTL_LOCKSTATE               1
949
#define SQLITE_GET_LOCKPROXYFILE             2
950
#define SQLITE_SET_LOCKPROXYFILE             3
951
#define SQLITE_LAST_ERRNO                    4
952
#define SQLITE_FCNTL_SIZE_HINT               5
953
#define SQLITE_FCNTL_CHUNK_SIZE              6
954
#define SQLITE_FCNTL_FILE_POINTER            7
955
#define SQLITE_FCNTL_SYNC_OMITTED            8
956
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
957
#define SQLITE_FCNTL_PERSIST_WAL            10
958
#define SQLITE_FCNTL_OVERWRITE              11
959
#define SQLITE_FCNTL_VFSNAME                12
960
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
961
#define SQLITE_FCNTL_PRAGMA                 14
962
#define SQLITE_FCNTL_BUSYHANDLER            15
963
#define SQLITE_FCNTL_TEMPFILENAME           16
964
#define SQLITE_FCNTL_MMAP_SIZE              18
965
#define SQLITE_FCNTL_TRACE                  19
966
#define SQLITE_FCNTL_HAS_MOVED              20
967
#define SQLITE_FCNTL_SYNC                   21
968
#define SQLITE_FCNTL_COMMIT_PHASETWO        22
969

    
970
/*
971
** CAPI3REF: Mutex Handle
972
**
973
** The mutex module within SQLite defines [sqlite3_mutex] to be an
974
** abstract type for a mutex object.  The SQLite core never looks
975
** at the internal representation of an [sqlite3_mutex].  It only
976
** deals with pointers to the [sqlite3_mutex] object.
977
**
978
** Mutexes are created using [sqlite3_mutex_alloc()].
979
*/
980
typedef struct sqlite3_mutex sqlite3_mutex;
981

    
982
/*
983
** CAPI3REF: OS Interface Object
984
**
985
** An instance of the sqlite3_vfs object defines the interface between
986
** the SQLite core and the underlying operating system.  The "vfs"
987
** in the name of the object stands for "virtual file system".  See
988
** the [VFS | VFS documentation] for further information.
989
**
990
** The value of the iVersion field is initially 1 but may be larger in
991
** future versions of SQLite.  Additional fields may be appended to this
992
** object when the iVersion value is increased.  Note that the structure
993
** of the sqlite3_vfs object changes in the transaction between
994
** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
995
** modified.
996
**
997
** The szOsFile field is the size of the subclassed [sqlite3_file]
998
** structure used by this VFS.  mxPathname is the maximum length of
999
** a pathname in this VFS.
1000
**
1001
** Registered sqlite3_vfs objects are kept on a linked list formed by
1002
** the pNext pointer.  The [sqlite3_vfs_register()]
1003
** and [sqlite3_vfs_unregister()] interfaces manage this list
1004
** in a thread-safe way.  The [sqlite3_vfs_find()] interface
1005
** searches the list.  Neither the application code nor the VFS
1006
** implementation should use the pNext pointer.
1007
**
1008
** The pNext field is the only field in the sqlite3_vfs
1009
** structure that SQLite will ever modify.  SQLite will only access
1010
** or modify this field while holding a particular static mutex.
1011
** The application should never modify anything within the sqlite3_vfs
1012
** object once the object has been registered.
1013
**
1014
** The zName field holds the name of the VFS module.  The name must
1015
** be unique across all VFS modules.
1016
**
1017
** [[sqlite3_vfs.xOpen]]
1018
** ^SQLite guarantees that the zFilename parameter to xOpen
1019
** is either a NULL pointer or string obtained
1020
** from xFullPathname() with an optional suffix added.
1021
** ^If a suffix is added to the zFilename parameter, it will
1022
** consist of a single "-" character followed by no more than
1023
** 11 alphanumeric and/or "-" characters.
1024
** ^SQLite further guarantees that
1025
** the string will be valid and unchanged until xClose() is
1026
** called. Because of the previous sentence,
1027
** the [sqlite3_file] can safely store a pointer to the
1028
** filename if it needs to remember the filename for some reason.
1029
** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1030
** must invent its own temporary name for the file.  ^Whenever the 
1031
** xFilename parameter is NULL it will also be the case that the
1032
** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1033
**
1034
** The flags argument to xOpen() includes all bits set in
1035
** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
1036
** or [sqlite3_open16()] is used, then flags includes at least
1037
** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 
1038
** If xOpen() opens a file read-only then it sets *pOutFlags to
1039
** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
1040
**
1041
** ^(SQLite will also add one of the following flags to the xOpen()
1042
** call, depending on the object being opened:
1043
**
1044
** <ul>
1045
** <li>  [SQLITE_OPEN_MAIN_DB]
1046
** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
1047
** <li>  [SQLITE_OPEN_TEMP_DB]
1048
** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
1049
** <li>  [SQLITE_OPEN_TRANSIENT_DB]
1050
** <li>  [SQLITE_OPEN_SUBJOURNAL]
1051
** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
1052
** <li>  [SQLITE_OPEN_WAL]
1053
** </ul>)^
1054
**
1055
** The file I/O implementation can use the object type flags to
1056
** change the way it deals with files.  For example, an application
1057
** that does not care about crash recovery or rollback might make
1058
** the open of a journal file a no-op.  Writes to this journal would
1059
** also be no-ops, and any attempt to read the journal would return
1060
** SQLITE_IOERR.  Or the implementation might recognize that a database
1061
** file will be doing page-aligned sector reads and writes in a random
1062
** order and set up its I/O subsystem accordingly.
1063
**
1064
** SQLite might also add one of the following flags to the xOpen method:
1065
**
1066
** <ul>
1067
** <li> [SQLITE_OPEN_DELETEONCLOSE]
1068
** <li> [SQLITE_OPEN_EXCLUSIVE]
1069
** </ul>
1070
**
1071
** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1072
** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
1073
** will be set for TEMP databases and their journals, transient
1074
** databases, and subjournals.
1075
**
1076
** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1077
** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1078
** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1079
** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 
1080
** SQLITE_OPEN_CREATE, is used to indicate that file should always
1081
** be created, and that it is an error if it already exists.
1082
** It is <i>not</i> used to indicate the file should be opened 
1083
** for exclusive access.
1084
**
1085
** ^At least szOsFile bytes of memory are allocated by SQLite
1086
** to hold the  [sqlite3_file] structure passed as the third
1087
** argument to xOpen.  The xOpen method does not have to
1088
** allocate the structure; it should just fill it in.  Note that
1089
** the xOpen method must set the sqlite3_file.pMethods to either
1090
** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
1091
** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
1092
** element will be valid after xOpen returns regardless of the success
1093
** or failure of the xOpen call.
1094
**
1095
** [[sqlite3_vfs.xAccess]]
1096
** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1097
** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1098
** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1099
** to test whether a file is at least readable.   The file can be a
1100
** directory.
1101
**
1102
** ^SQLite will always allocate at least mxPathname+1 bytes for the
1103
** output buffer xFullPathname.  The exact size of the output buffer
1104
** is also passed as a parameter to both  methods. If the output buffer
1105
** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1106
** handled as a fatal error by SQLite, vfs implementations should endeavor
1107
** to prevent this by setting mxPathname to a sufficiently large value.
1108
**
1109
** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1110
** interfaces are not strictly a part of the filesystem, but they are
1111
** included in the VFS structure for completeness.
1112
** The xRandomness() function attempts to return nBytes bytes
1113
** of good-quality randomness into zOut.  The return value is
1114
** the actual number of bytes of randomness obtained.
1115
** The xSleep() method causes the calling thread to sleep for at
1116
** least the number of microseconds given.  ^The xCurrentTime()
1117
** method returns a Julian Day Number for the current date and time as
1118
** a floating point value.
1119
** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1120
** Day Number multiplied by 86400000 (the number of milliseconds in 
1121
** a 24-hour day).  
1122
** ^SQLite will use the xCurrentTimeInt64() method to get the current
1123
** date and time if that method is available (if iVersion is 2 or 
1124
** greater and the function pointer is not NULL) and will fall back
1125
** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1126
**
1127
** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1128
** are not used by the SQLite core.  These optional interfaces are provided
1129
** by some VFSes to facilitate testing of the VFS code. By overriding 
1130
** system calls with functions under its control, a test program can
1131
** simulate faults and error conditions that would otherwise be difficult
1132
** or impossible to induce.  The set of system calls that can be overridden
1133
** varies from one VFS to another, and from one version of the same VFS to the
1134
** next.  Applications that use these interfaces must be prepared for any
1135
** or all of these interfaces to be NULL or for their behavior to change
1136
** from one release to the next.  Applications must not attempt to access
1137
** any of these methods if the iVersion of the VFS is less than 3.
1138
*/
1139
typedef struct sqlite3_vfs sqlite3_vfs;
1140
typedef void (*sqlite3_syscall_ptr)(void);
1141
struct sqlite3_vfs {
1142
  int iVersion;            /* Structure version number (currently 3) */
1143
  int szOsFile;            /* Size of subclassed sqlite3_file */
1144
  int mxPathname;          /* Maximum file pathname length */
1145
  sqlite3_vfs *pNext;      /* Next registered VFS */
1146
  const char *zName;       /* Name of this virtual file system */
1147
  void *pAppData;          /* Pointer to application-specific data */
1148
  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1149
               int flags, int *pOutFlags);
1150
  int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1151
  int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1152
  int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1153
  void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1154
  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1155
  void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1156
  void (*xDlClose)(sqlite3_vfs*, void*);
1157
  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1158
  int (*xSleep)(sqlite3_vfs*, int microseconds);
1159
  int (*xCurrentTime)(sqlite3_vfs*, double*);
1160
  int (*xGetLastError)(sqlite3_vfs*, int, char *);
1161
  /*
1162
  ** The methods above are in version 1 of the sqlite_vfs object
1163
  ** definition.  Those that follow are added in version 2 or later
1164
  */
1165
  int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1166
  /*
1167
  ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1168
  ** Those below are for version 3 and greater.
1169
  */
1170
  int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1171
  sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1172
  const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1173
  /*
1174
  ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1175
  ** New fields may be appended in figure versions.  The iVersion
1176
  ** value will increment whenever this happens. 
1177
  */
1178
};
1179

    
1180
/*
1181
** CAPI3REF: Flags for the xAccess VFS method
1182
**
1183
** These integer constants can be used as the third parameter to
1184
** the xAccess method of an [sqlite3_vfs] object.  They determine
1185
** what kind of permissions the xAccess method is looking for.
1186
** With SQLITE_ACCESS_EXISTS, the xAccess method
1187
** simply checks whether the file exists.
1188
** With SQLITE_ACCESS_READWRITE, the xAccess method
1189
** checks whether the named directory is both readable and writable
1190
** (in other words, if files can be added, removed, and renamed within
1191
** the directory).
1192
** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1193
** [temp_store_directory pragma], though this could change in a future
1194
** release of SQLite.
1195
** With SQLITE_ACCESS_READ, the xAccess method
1196
** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
1197
** currently unused, though it might be used in a future release of
1198
** SQLite.
1199
*/
1200
#define SQLITE_ACCESS_EXISTS    0
1201
#define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
1202
#define SQLITE_ACCESS_READ      2   /* Unused */
1203

    
1204
/*
1205
** CAPI3REF: Flags for the xShmLock VFS method
1206
**
1207
** These integer constants define the various locking operations
1208
** allowed by the xShmLock method of [sqlite3_io_methods].  The
1209
** following are the only legal combinations of flags to the
1210
** xShmLock method:
1211
**
1212
** <ul>
1213
** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1214
** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1215
** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1216
** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1217
** </ul>
1218
**
1219
** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1220
** was given no the corresponding lock.  
1221
**
1222
** The xShmLock method can transition between unlocked and SHARED or
1223
** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
1224
** and EXCLUSIVE.
1225
*/
1226
#define SQLITE_SHM_UNLOCK       1
1227
#define SQLITE_SHM_LOCK         2
1228
#define SQLITE_SHM_SHARED       4
1229
#define SQLITE_SHM_EXCLUSIVE    8
1230

    
1231
/*
1232
** CAPI3REF: Maximum xShmLock index
1233
**
1234
** The xShmLock method on [sqlite3_io_methods] may use values
1235
** between 0 and this upper bound as its "offset" argument.
1236
** The SQLite core will never attempt to acquire or release a
1237
** lock outside of this range
1238
*/
1239
#define SQLITE_SHM_NLOCK        8
1240

    
1241

    
1242
/*
1243
** CAPI3REF: Initialize The SQLite Library
1244
**
1245
** ^The sqlite3_initialize() routine initializes the
1246
** SQLite library.  ^The sqlite3_shutdown() routine
1247
** deallocates any resources that were allocated by sqlite3_initialize().
1248
** These routines are designed to aid in process initialization and
1249
** shutdown on embedded systems.  Workstation applications using
1250
** SQLite normally do not need to invoke either of these routines.
1251
**
1252
** A call to sqlite3_initialize() is an "effective" call if it is
1253
** the first time sqlite3_initialize() is invoked during the lifetime of
1254
** the process, or if it is the first time sqlite3_initialize() is invoked
1255
** following a call to sqlite3_shutdown().  ^(Only an effective call
1256
** of sqlite3_initialize() does any initialization.  All other calls
1257
** are harmless no-ops.)^
1258
**
1259
** A call to sqlite3_shutdown() is an "effective" call if it is the first
1260
** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
1261
** an effective call to sqlite3_shutdown() does any deinitialization.
1262
** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1263
**
1264
** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1265
** is not.  The sqlite3_shutdown() interface must only be called from a
1266
** single thread.  All open [database connections] must be closed and all
1267
** other SQLite resources must be deallocated prior to invoking
1268
** sqlite3_shutdown().
1269
**
1270
** Among other things, ^sqlite3_initialize() will invoke
1271
** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
1272
** will invoke sqlite3_os_end().
1273
**
1274
** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1275
** ^If for some reason, sqlite3_initialize() is unable to initialize
1276
** the library (perhaps it is unable to allocate a needed resource such
1277
** as a mutex) it returns an [error code] other than [SQLITE_OK].
1278
**
1279
** ^The sqlite3_initialize() routine is called internally by many other
1280
** SQLite interfaces so that an application usually does not need to
1281
** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
1282
** calls sqlite3_initialize() so the SQLite library will be automatically
1283
** initialized when [sqlite3_open()] is called if it has not be initialized
1284
** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1285
** compile-time option, then the automatic calls to sqlite3_initialize()
1286
** are omitted and the application must call sqlite3_initialize() directly
1287
** prior to using any other SQLite interface.  For maximum portability,
1288
** it is recommended that applications always invoke sqlite3_initialize()
1289
** directly prior to using any other SQLite interface.  Future releases
1290
** of SQLite may require this.  In other words, the behavior exhibited
1291
** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1292
** default behavior in some future release of SQLite.
1293
**
1294
** The sqlite3_os_init() routine does operating-system specific
1295
** initialization of the SQLite library.  The sqlite3_os_end()
1296
** routine undoes the effect of sqlite3_os_init().  Typical tasks
1297
** performed by these routines include allocation or deallocation
1298
** of static resources, initialization of global variables,
1299
** setting up a default [sqlite3_vfs] module, or setting up
1300
** a default configuration using [sqlite3_config()].
1301
**
1302
** The application should never invoke either sqlite3_os_init()
1303
** or sqlite3_os_end() directly.  The application should only invoke
1304
** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
1305
** interface is called automatically by sqlite3_initialize() and
1306
** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
1307
** implementations for sqlite3_os_init() and sqlite3_os_end()
1308
** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1309
** When [custom builds | built for other platforms]
1310
** (using the [SQLITE_OS_OTHER=1] compile-time
1311
** option) the application must supply a suitable implementation for
1312
** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
1313
** implementation of sqlite3_os_init() or sqlite3_os_end()
1314
** must return [SQLITE_OK] on success and some other [error code] upon
1315
** failure.
1316
*/
1317
SQLITE_API int sqlite3_initialize(void);
1318
SQLITE_API int sqlite3_shutdown(void);
1319
SQLITE_API int sqlite3_os_init(void);
1320
SQLITE_API int sqlite3_os_end(void);
1321

    
1322
/*
1323
** CAPI3REF: Configuring The SQLite Library
1324
**
1325
** The sqlite3_config() interface is used to make global configuration
1326
** changes to SQLite in order to tune SQLite to the specific needs of
1327
** the application.  The default configuration is recommended for most
1328
** applications and so this routine is usually not necessary.  It is
1329
** provided to support rare applications with unusual needs.
1330
**
1331
** The sqlite3_config() interface is not threadsafe.  The application
1332
** must insure that no other SQLite interfaces are invoked by other
1333
** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
1334
** may only be invoked prior to library initialization using
1335
** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1336
** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1337
** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1338
** Note, however, that ^sqlite3_config() can be called as part of the
1339
** implementation of an application-defined [sqlite3_os_init()].
1340
**
1341
** The first argument to sqlite3_config() is an integer
1342
** [configuration option] that determines
1343
** what property of SQLite is to be configured.  Subsequent arguments
1344
** vary depending on the [configuration option]
1345
** in the first argument.
1346
**
1347
** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1348
** ^If the option is unknown or SQLite is unable to set the option
1349
** then this routine returns a non-zero [error code].
1350
*/
1351
SQLITE_API int sqlite3_config(int, ...);
1352

    
1353
/*
1354
** CAPI3REF: Configure database connections
1355
**
1356
** The sqlite3_db_config() interface is used to make configuration
1357
** changes to a [database connection].  The interface is similar to
1358
** [sqlite3_config()] except that the changes apply to a single
1359
** [database connection] (specified in the first argument).
1360
**
1361
** The second argument to sqlite3_db_config(D,V,...)  is the
1362
** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 
1363
** that indicates what aspect of the [database connection] is being configured.
1364
** Subsequent arguments vary depending on the configuration verb.
1365
**
1366
** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1367
** the call is considered successful.
1368
*/
1369
SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1370

    
1371
/*
1372
** CAPI3REF: Memory Allocation Routines
1373
**
1374
** An instance of this object defines the interface between SQLite
1375
** and low-level memory allocation routines.
1376
**
1377
** This object is used in only one place in the SQLite interface.
1378
** A pointer to an instance of this object is the argument to
1379
** [sqlite3_config()] when the configuration option is
1380
** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].  
1381
** By creating an instance of this object
1382
** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1383
** during configuration, an application can specify an alternative
1384
** memory allocation subsystem for SQLite to use for all of its
1385
** dynamic memory needs.
1386
**
1387
** Note that SQLite comes with several [built-in memory allocators]
1388
** that are perfectly adequate for the overwhelming majority of applications
1389
** and that this object is only useful to a tiny minority of applications
1390
** with specialized memory allocation requirements.  This object is
1391
** also used during testing of SQLite in order to specify an alternative
1392
** memory allocator that simulates memory out-of-memory conditions in
1393
** order to verify that SQLite recovers gracefully from such
1394
** conditions.
1395
**
1396
** The xMalloc, xRealloc, and xFree methods must work like the
1397
** malloc(), realloc() and free() functions from the standard C library.
1398
** ^SQLite guarantees that the second argument to
1399
** xRealloc is always a value returned by a prior call to xRoundup.
1400
**
1401
** xSize should return the allocated size of a memory allocation
1402
** previously obtained from xMalloc or xRealloc.  The allocated size
1403
** is always at least as big as the requested size but may be larger.
1404
**
1405
** The xRoundup method returns what would be the allocated size of
1406
** a memory allocation given a particular requested size.  Most memory
1407
** allocators round up memory allocations at least to the next multiple
1408
** of 8.  Some allocators round up to a larger multiple or to a power of 2.
1409
** Every memory allocation request coming in through [sqlite3_malloc()]
1410
** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0, 
1411
** that causes the corresponding memory allocation to fail.
1412
**
1413
** The xInit method initializes the memory allocator.  For example,
1414
** it might allocate any require mutexes or initialize internal data
1415
** structures.  The xShutdown method is invoked (indirectly) by
1416
** [sqlite3_shutdown()] and should deallocate any resources acquired
1417
** by xInit.  The pAppData pointer is used as the only parameter to
1418
** xInit and xShutdown.
1419
**
1420
** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1421
** the xInit method, so the xInit method need not be threadsafe.  The
1422
** xShutdown method is only called from [sqlite3_shutdown()] so it does
1423
** not need to be threadsafe either.  For all other methods, SQLite
1424
** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1425
** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1426
** it is by default) and so the methods are automatically serialized.
1427
** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1428
** methods must be threadsafe or else make their own arrangements for
1429
** serialization.
1430
**
1431
** SQLite will never invoke xInit() more than once without an intervening
1432
** call to xShutdown().
1433
*/
1434
typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1435
struct sqlite3_mem_methods {
1436
  void *(*xMalloc)(int);         /* Memory allocation function */
1437
  void (*xFree)(void*);          /* Free a prior allocation */
1438
  void *(*xRealloc)(void*,int);  /* Resize an allocation */
1439
  int (*xSize)(void*);           /* Return the size of an allocation */
1440
  int (*xRoundup)(int);          /* Round up request size to allocation size */
1441
  int (*xInit)(void*);           /* Initialize the memory allocator */
1442
  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
1443
  void *pAppData;                /* Argument to xInit() and xShutdown() */
1444
};
1445

    
1446
/*
1447
** CAPI3REF: Configuration Options
1448
** KEYWORDS: {configuration option}
1449
**
1450
** These constants are the available integer configuration options that
1451
** can be passed as the first argument to the [sqlite3_config()] interface.
1452
**
1453
** New configuration options may be added in future releases of SQLite.
1454
** Existing configuration options might be discontinued.  Applications
1455
** should check the return code from [sqlite3_config()] to make sure that
1456
** the call worked.  The [sqlite3_config()] interface will return a
1457
** non-zero [error code] if a discontinued or unsupported configuration option
1458
** is invoked.
1459
**
1460
** <dl>
1461
** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1462
** <dd>There are no arguments to this option.  ^This option sets the
1463
** [threading mode] to Single-thread.  In other words, it disables
1464
** all mutexing and puts SQLite into a mode where it can only be used
1465
** by a single thread.   ^If SQLite is compiled with
1466
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1467
** it is not possible to change the [threading mode] from its default
1468
** value of Single-thread and so [sqlite3_config()] will return 
1469
** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1470
** configuration option.</dd>
1471
**
1472
** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1473
** <dd>There are no arguments to this option.  ^This option sets the
1474
** [threading mode] to Multi-thread.  In other words, it disables
1475
** mutexing on [database connection] and [prepared statement] objects.
1476
** The application is responsible for serializing access to
1477
** [database connections] and [prepared statements].  But other mutexes
1478
** are enabled so that SQLite will be safe to use in a multi-threaded
1479
** environment as long as no two threads attempt to use the same
1480
** [database connection] at the same time.  ^If SQLite is compiled with
1481
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1482
** it is not possible to set the Multi-thread [threading mode] and
1483
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1484
** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1485
**
1486
** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1487
** <dd>There are no arguments to this option.  ^This option sets the
1488
** [threading mode] to Serialized. In other words, this option enables
1489
** all mutexes including the recursive
1490
** mutexes on [database connection] and [prepared statement] objects.
1491
** In this mode (which is the default when SQLite is compiled with
1492
** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1493
** to [database connections] and [prepared statements] so that the
1494
** application is free to use the same [database connection] or the
1495
** same [prepared statement] in different threads at the same time.
1496
** ^If SQLite is compiled with
1497
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1498
** it is not possible to set the Serialized [threading mode] and
1499
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1500
** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1501
**
1502
** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1503
** <dd> ^(This option takes a single argument which is a pointer to an
1504
** instance of the [sqlite3_mem_methods] structure.  The argument specifies
1505
** alternative low-level memory allocation routines to be used in place of
1506
** the memory allocation routines built into SQLite.)^ ^SQLite makes
1507
** its own private copy of the content of the [sqlite3_mem_methods] structure
1508
** before the [sqlite3_config()] call returns.</dd>
1509
**
1510
** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1511
** <dd> ^(This option takes a single argument which is a pointer to an
1512
** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]
1513
** structure is filled with the currently defined memory allocation routines.)^
1514
** This option can be used to overload the default memory allocation
1515
** routines with a wrapper that simulations memory allocation failure or
1516
** tracks memory usage, for example. </dd>
1517
**
1518
** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1519
** <dd> ^This option takes single argument of type int, interpreted as a 
1520
** boolean, which enables or disables the collection of memory allocation 
1521
** statistics. ^(When memory allocation statistics are disabled, the 
1522
** following SQLite interfaces become non-operational:
1523
**   <ul>
1524
**   <li> [sqlite3_memory_used()]
1525
**   <li> [sqlite3_memory_highwater()]
1526
**   <li> [sqlite3_soft_heap_limit64()]
1527
**   <li> [sqlite3_status()]
1528
**   </ul>)^
1529
** ^Memory allocation statistics are enabled by default unless SQLite is
1530
** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1531
** allocation statistics are disabled by default.
1532
** </dd>
1533
**
1534
** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1535
** <dd> ^This option specifies a static memory buffer that SQLite can use for
1536
** scratch memory.  There are three arguments:  A pointer an 8-byte
1537
** aligned memory buffer from which the scratch allocations will be
1538
** drawn, the size of each scratch allocation (sz),
1539
** and the maximum number of scratch allocations (N).  The sz
1540
** argument must be a multiple of 16.
1541
** The first argument must be a pointer to an 8-byte aligned buffer
1542
** of at least sz*N bytes of memory.
1543
** ^SQLite will use no more than two scratch buffers per thread.  So
1544
** N should be set to twice the expected maximum number of threads.
1545
** ^SQLite will never require a scratch buffer that is more than 6
1546
** times the database page size. ^If SQLite needs needs additional
1547
** scratch memory beyond what is provided by this configuration option, then 
1548
** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
1549
**
1550
** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1551
** <dd> ^This option specifies a static memory buffer that SQLite can use for
1552
** the database page cache with the default page cache implementation.  
1553
** This configuration should not be used if an application-define page
1554
** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.
1555
** There are three arguments to this option: A pointer to 8-byte aligned
1556
** memory, the size of each page buffer (sz), and the number of pages (N).
1557
** The sz argument should be the size of the largest database page
1558
** (a power of two between 512 and 32768) plus a little extra for each
1559
** page header.  ^The page header size is 20 to 40 bytes depending on
1560
** the host architecture.  ^It is harmless, apart from the wasted memory,
1561
** to make sz a little too large.  The first
1562
** argument should point to an allocation of at least sz*N bytes of memory.
1563
** ^SQLite will use the memory provided by the first argument to satisfy its
1564
** memory needs for the first N pages that it adds to cache.  ^If additional
1565
** page cache memory is needed beyond what is provided by this option, then
1566
** SQLite goes to [sqlite3_malloc()] for the additional storage space.
1567
** The pointer in the first argument must
1568
** be aligned to an 8-byte boundary or subsequent behavior of SQLite
1569
** will be undefined.</dd>
1570
**
1571
** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1572
** <dd> ^This option specifies a static memory buffer that SQLite will use
1573
** for all of its dynamic memory allocation needs beyond those provided
1574
** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
1575
** There are three arguments: An 8-byte aligned pointer to the memory,
1576
** the number of bytes in the memory buffer, and the minimum allocation size.
1577
** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1578
** to using its default memory allocator (the system malloc() implementation),
1579
** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
1580
** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1581
** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
1582
** allocator is engaged to handle all of SQLites memory allocation needs.
1583
** The first pointer (the memory pointer) must be aligned to an 8-byte
1584
** boundary or subsequent behavior of SQLite will be undefined.
1585
** The minimum allocation size is capped at 2**12. Reasonable values
1586
** for the minimum allocation size are 2**5 through 2**8.</dd>
1587
**
1588
** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1589
** <dd> ^(This option takes a single argument which is a pointer to an
1590
** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
1591
** alternative low-level mutex routines to be used in place
1592
** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
1593
** content of the [sqlite3_mutex_methods] structure before the call to
1594
** [sqlite3_config()] returns. ^If SQLite is compiled with
1595
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1596
** the entire mutexing subsystem is omitted from the build and hence calls to
1597
** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1598
** return [SQLITE_ERROR].</dd>
1599
**
1600
** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1601
** <dd> ^(This option takes a single argument which is a pointer to an
1602
** instance of the [sqlite3_mutex_methods] structure.  The
1603
** [sqlite3_mutex_methods]
1604
** structure is filled with the currently defined mutex routines.)^
1605
** This option can be used to overload the default mutex allocation
1606
** routines with a wrapper used to track mutex usage for performance
1607
** profiling or testing, for example.   ^If SQLite is compiled with
1608
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1609
** the entire mutexing subsystem is omitted from the build and hence calls to
1610
** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1611
** return [SQLITE_ERROR].</dd>
1612
**
1613
** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1614
** <dd> ^(This option takes two arguments that determine the default
1615
** memory allocation for the lookaside memory allocator on each
1616
** [database connection].  The first argument is the
1617
** size of each lookaside buffer slot and the second is the number of
1618
** slots allocated to each database connection.)^  ^(This option sets the
1619
** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1620
** verb to [sqlite3_db_config()] can be used to change the lookaside
1621
** configuration on individual connections.)^ </dd>
1622
**
1623
** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1624
** <dd> ^(This option takes a single argument which is a pointer to
1625
** an [sqlite3_pcache_methods2] object.  This object specifies the interface
1626
** to a custom page cache implementation.)^  ^SQLite makes a copy of the
1627
** object and uses it for page cache memory allocations.</dd>
1628
**
1629
** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1630
** <dd> ^(This option takes a single argument which is a pointer to an
1631
** [sqlite3_pcache_methods2] object.  SQLite copies of the current
1632
** page cache implementation into that object.)^ </dd>
1633
**
1634
** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1635
** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1636
** global [error log].
1637
** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1638
** function with a call signature of void(*)(void*,int,const char*), 
1639
** and a pointer to void. ^If the function pointer is not NULL, it is
1640
** invoked by [sqlite3_log()] to process each logging event.  ^If the
1641
** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1642
** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1643
** passed through as the first parameter to the application-defined logger
1644
** function whenever that function is invoked.  ^The second parameter to
1645
** the logger function is a copy of the first parameter to the corresponding
1646
** [sqlite3_log()] call and is intended to be a [result code] or an
1647
** [extended result code].  ^The third parameter passed to the logger is
1648
** log message after formatting via [sqlite3_snprintf()].
1649
** The SQLite logging interface is not reentrant; the logger function
1650
** supplied by the application must not invoke any SQLite interface.
1651
** In a multi-threaded application, the application-defined logger
1652
** function must be threadsafe. </dd>
1653
**
1654
** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1655
** <dd>^(This option takes a single argument of type int. If non-zero, then
1656
** URI handling is globally enabled. If the parameter is zero, then URI handling
1657
** is globally disabled.)^ ^If URI handling is globally enabled, all filenames
1658
** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
1659
** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1660
** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1661
** connection is opened. ^If it is globally disabled, filenames are
1662
** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1663
** database connection is opened. ^(By default, URI handling is globally
1664
** disabled. The default value may be changed by compiling with the
1665
** [SQLITE_USE_URI] symbol defined.)^
1666
**
1667
** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1668
** <dd>^This option takes a single integer argument which is interpreted as
1669
** a boolean in order to enable or disable the use of covering indices for
1670
** full table scans in the query optimizer.  ^The default setting is determined
1671
** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1672
** if that compile-time option is omitted.
1673
** The ability to disable the use of covering indices for full table scans
1674
** is because some incorrectly coded legacy applications might malfunction
1675
** when the optimization is enabled.  Providing the ability to
1676
** disable the optimization allows the older, buggy application code to work
1677
** without change even with newer versions of SQLite.
1678
**
1679
** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1680
** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1681
** <dd> These options are obsolete and should not be used by new code.
1682
** They are retained for backwards compatibility but are now no-ops.
1683
** </dd>
1684
**
1685
** [[SQLITE_CONFIG_SQLLOG]]
1686
** <dt>SQLITE_CONFIG_SQLLOG
1687
** <dd>This option is only available if sqlite is compiled with the
1688
** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1689
** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1690
** The second should be of type (void*). The callback is invoked by the library
1691
** in three separate circumstances, identified by the value passed as the
1692
** fourth parameter. If the fourth parameter is 0, then the database connection
1693
** passed as the second argument has just been opened. The third argument
1694
** points to a buffer containing the name of the main database file. If the
1695
** fourth parameter is 1, then the SQL statement that the third parameter
1696
** points to has just been executed. Or, if the fourth parameter is 2, then
1697
** the connection being passed as the second parameter is being closed. The
1698
** third parameter is passed NULL In this case.  An example of using this
1699
** configuration option can be seen in the "test_sqllog.c" source file in
1700
** the canonical SQLite source tree.</dd>
1701
**
1702
** [[SQLITE_CONFIG_MMAP_SIZE]]
1703
** <dt>SQLITE_CONFIG_MMAP_SIZE
1704
** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1705
** that are the default mmap size limit (the default setting for
1706
** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1707
** ^The default setting can be overridden by each database connection using
1708
** either the [PRAGMA mmap_size] command, or by using the
1709
** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
1710
** cannot be changed at run-time.  Nor may the maximum allowed mmap size
1711
** exceed the compile-time maximum mmap size set by the
1712
** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1713
** ^If either argument to this option is negative, then that argument is
1714
** changed to its compile-time default.
1715
**
1716
** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1717
** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1718
** <dd>^This option is only available if SQLite is compiled for Windows
1719
** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined.
1720
** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1721
** that specifies the maximum size of the created heap.
1722
** </dl>
1723
*/
1724
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
1725
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
1726
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
1727
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
1728
#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
1729
#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
1730
#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
1731
#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
1732
#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
1733
#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
1734
#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
1735
/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 
1736
#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
1737
#define SQLITE_CONFIG_PCACHE       14  /* no-op */
1738
#define SQLITE_CONFIG_GETPCACHE    15  /* no-op */
1739
#define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
1740
#define SQLITE_CONFIG_URI          17  /* int */
1741
#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
1742
#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
1743
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
1744
#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
1745
#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
1746
#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
1747

    
1748
/*
1749
** CAPI3REF: Database Connection Configuration Options
1750
**
1751
** These constants are the available integer configuration options that
1752
** can be passed as the second argument to the [sqlite3_db_config()] interface.
1753
**
1754
** New configuration options may be added in future releases of SQLite.
1755
** Existing configuration options might be discontinued.  Applications
1756
** should check the return code from [sqlite3_db_config()] to make sure that
1757
** the call worked.  ^The [sqlite3_db_config()] interface will return a
1758
** non-zero [error code] if a discontinued or unsupported configuration option
1759
** is invoked.
1760
**
1761
** <dl>
1762
** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1763
** <dd> ^This option takes three additional arguments that determine the 
1764
** [lookaside memory allocator] configuration for the [database connection].
1765
** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1766
** pointer to a memory buffer to use for lookaside memory.
1767
** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1768
** may be NULL in which case SQLite will allocate the
1769
** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1770
** size of each lookaside buffer slot.  ^The third argument is the number of
1771
** slots.  The size of the buffer in the first argument must be greater than
1772
** or equal to the product of the second and third arguments.  The buffer
1773
** must be aligned to an 8-byte boundary.  ^If the second argument to
1774
** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1775
** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
1776
** configuration for a database connection can only be changed when that
1777
** connection is not currently using lookaside memory, or in other words
1778
** when the "current value" returned by
1779
** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1780
** Any attempt to change the lookaside memory configuration when lookaside
1781
** memory is in use leaves the configuration unchanged and returns 
1782
** [SQLITE_BUSY].)^</dd>
1783
**
1784
** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
1785
** <dd> ^This option is used to enable or disable the enforcement of
1786
** [foreign key constraints].  There should be two additional arguments.
1787
** The first argument is an integer which is 0 to disable FK enforcement,
1788
** positive to enable FK enforcement or negative to leave FK enforcement
1789
** unchanged.  The second parameter is a pointer to an integer into which
1790
** is written 0 or 1 to indicate whether FK enforcement is off or on
1791
** following this call.  The second parameter may be a NULL pointer, in
1792
** which case the FK enforcement setting is not reported back. </dd>
1793
**
1794
** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
1795
** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
1796
** There should be two additional arguments.
1797
** The first argument is an integer which is 0 to disable triggers,
1798
** positive to enable triggers or negative to leave the setting unchanged.
1799
** The second parameter is a pointer to an integer into which
1800
** is written 0 or 1 to indicate whether triggers are disabled or enabled
1801
** following this call.  The second parameter may be a NULL pointer, in
1802
** which case the trigger setting is not reported back. </dd>
1803
**
1804
** </dl>
1805
*/
1806
#define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
1807
#define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
1808
#define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
1809

    
1810

    
1811
/*
1812
** CAPI3REF: Enable Or Disable Extended Result Codes
1813
**
1814
** ^The sqlite3_extended_result_codes() routine enables or disables the
1815
** [extended result codes] feature of SQLite. ^The extended result
1816
** codes are disabled by default for historical compatibility.
1817
*/
1818
SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
1819

    
1820
/*
1821
** CAPI3REF: Last Insert Rowid
1822
**
1823
** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
1824
** has a unique 64-bit signed
1825
** integer key called the [ROWID | "rowid"]. ^The rowid is always available
1826
** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
1827
** names are not also used by explicitly declared columns. ^If
1828
** the table has a column of type [INTEGER PRIMARY KEY] then that column
1829
** is another alias for the rowid.
1830
**
1831
** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 
1832
** most recent successful [INSERT] into a rowid table or [virtual table]
1833
** on database connection D.
1834
** ^Inserts into [WITHOUT ROWID] tables are not recorded.
1835
** ^If no successful [INSERT]s into rowid tables
1836
** have ever occurred on the database connection D, 
1837
** then sqlite3_last_insert_rowid(D) returns zero.
1838
**
1839
** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
1840
** method, then this routine will return the [rowid] of the inserted
1841
** row as long as the trigger or virtual table method is running.
1842
** But once the trigger or virtual table method ends, the value returned 
1843
** by this routine reverts to what it was before the trigger or virtual
1844
** table method began.)^
1845
**
1846
** ^An [INSERT] that fails due to a constraint violation is not a
1847
** successful [INSERT] and does not change the value returned by this
1848
** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
1849
** and INSERT OR ABORT make no changes to the return value of this
1850
** routine when their insertion fails.  ^(When INSERT OR REPLACE
1851
** encounters a constraint violation, it does not fail.  The
1852
** INSERT continues to completion after deleting rows that caused
1853
** the constraint problem so INSERT OR REPLACE will always change
1854
** the return value of this interface.)^
1855
**
1856
** ^For the purposes of this routine, an [INSERT] is considered to
1857
** be successful even if it is subsequently rolled back.
1858
**
1859
** This function is accessible to SQL statements via the
1860
** [last_insert_rowid() SQL function].
1861
**
1862
** If a separate thread performs a new [INSERT] on the same
1863
** database connection while the [sqlite3_last_insert_rowid()]
1864
** function is running and thus changes the last insert [rowid],
1865
** then the value returned by [sqlite3_last_insert_rowid()] is
1866
** unpredictable and might not equal either the old or the new
1867
** last insert [rowid].
1868
*/
1869
SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
1870

    
1871
/*
1872
** CAPI3REF: Count The Number Of Rows Modified
1873
**
1874
** ^This function returns the number of database rows that were changed
1875
** or inserted or deleted by the most recently completed SQL statement
1876
** on the [database connection] specified by the first parameter.
1877
** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
1878
** or [DELETE] statement are counted.  Auxiliary changes caused by
1879
** triggers or [foreign key actions] are not counted.)^ Use the
1880
** [sqlite3_total_changes()] function to find the total number of changes
1881
** including changes caused by triggers and foreign key actions.
1882
**
1883
** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
1884
** are not counted.  Only real table changes are counted.
1885
**
1886
** ^(A "row change" is a change to a single row of a single table
1887
** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
1888
** are changed as side effects of [REPLACE] constraint resolution,
1889
** rollback, ABORT processing, [DROP TABLE], or by any other
1890
** mechanisms do not count as direct row changes.)^
1891
**
1892
** A "trigger context" is a scope of execution that begins and
1893
** ends with the script of a [CREATE TRIGGER | trigger]. 
1894
** Most SQL statements are
1895
** evaluated outside of any trigger.  This is the "top level"
1896
** trigger context.  If a trigger fires from the top level, a
1897
** new trigger context is entered for the duration of that one
1898
** trigger.  Subtriggers create subcontexts for their duration.
1899
**
1900
** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
1901
** not create a new trigger context.
1902
**
1903
** ^This function returns the number of direct row changes in the
1904
** most recent INSERT, UPDATE, or DELETE statement within the same
1905
** trigger context.
1906
**
1907
** ^Thus, when called from the top level, this function returns the
1908
** number of changes in the most recent INSERT, UPDATE, or DELETE
1909
** that also occurred at the top level.  ^(Within the body of a trigger,
1910
** the sqlite3_changes() interface can be called to find the number of
1911
** changes in the most recently completed INSERT, UPDATE, or DELETE
1912
** statement within the body of the same trigger.
1913
** However, the number returned does not include changes
1914
** caused by subtriggers since those have their own context.)^
1915
**
1916
** See also the [sqlite3_total_changes()] interface, the
1917
** [count_changes pragma], and the [changes() SQL function].
1918
**
1919
** If a separate thread makes changes on the same database connection
1920
** while [sqlite3_changes()] is running then the value returned
1921
** is unpredictable and not meaningful.
1922
*/
1923
SQLITE_API int sqlite3_changes(sqlite3*);
1924

    
1925
/*
1926
** CAPI3REF: Total Number Of Rows Modified
1927
**
1928
** ^This function returns the number of row changes caused by [INSERT],
1929
** [UPDATE] or [DELETE] statements since the [database connection] was opened.
1930
** ^(The count returned by sqlite3_total_changes() includes all changes
1931
** from all [CREATE TRIGGER | trigger] contexts and changes made by
1932
** [foreign key actions]. However,
1933
** the count does not include changes used to implement [REPLACE] constraints,
1934
** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
1935
** count does not include rows of views that fire an [INSTEAD OF trigger],
1936
** though if the INSTEAD OF trigger makes changes of its own, those changes 
1937
** are counted.)^
1938
** ^The sqlite3_total_changes() function counts the changes as soon as
1939
** the statement that makes them is completed (when the statement handle
1940
** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
1941
**
1942
** See also the [sqlite3_changes()] interface, the
1943
** [count_changes pragma], and the [total_changes() SQL function].
1944
**
1945
** If a separate thread makes changes on the same database connection
1946
** while [sqlite3_total_changes()] is running then the value
1947
** returned is unpredictable and not meaningful.
1948
*/
1949
SQLITE_API int sqlite3_total_changes(sqlite3*);
1950

    
1951
/*
1952
** CAPI3REF: Interrupt A Long-Running Query
1953
**
1954
** ^This function causes any pending database operation to abort and
1955
** return at its earliest opportunity. This routine is typically
1956
** called in response to a user action such as pressing "Cancel"
1957
** or Ctrl-C where the user wants a long query operation to halt
1958
** immediately.
1959
**
1960
** ^It is safe to call this routine from a thread different from the
1961
** thread that is currently running the database operation.  But it
1962
** is not safe to call this routine with a [database connection] that
1963
** is closed or might close before sqlite3_interrupt() returns.
1964
**
1965
** ^If an SQL operation is very nearly finished at the time when
1966
** sqlite3_interrupt() is called, then it might not have an opportunity
1967
** to be interrupted and might continue to completion.
1968
**
1969
** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
1970
** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
1971
** that is inside an explicit transaction, then the entire transaction
1972
** will be rolled back automatically.
1973
**
1974
** ^The sqlite3_interrupt(D) call is in effect until all currently running
1975
** SQL statements on [database connection] D complete.  ^Any new SQL statements
1976
** that are started after the sqlite3_interrupt() call and before the 
1977
** running statements reaches zero are interrupted as if they had been
1978
** running prior to the sqlite3_interrupt() call.  ^New SQL statements
1979
** that are started after the running statement count reaches zero are
1980
** not effected by the sqlite3_interrupt().
1981
** ^A call to sqlite3_interrupt(D) that occurs when there are no running
1982
** SQL statements is a no-op and has no effect on SQL statements
1983
** that are started after the sqlite3_interrupt() call returns.
1984
**
1985
** If the database connection closes while [sqlite3_interrupt()]
1986
** is running then bad things will likely happen.
1987
*/
1988
SQLITE_API void sqlite3_interrupt(sqlite3*);
1989

    
1990
/*
1991
** CAPI3REF: Determine If An SQL Statement Is Complete
1992
**
1993
** These routines are useful during command-line input to determine if the
1994
** currently entered text seems to form a complete SQL statement or
1995
** if additional input is needed before sending the text into
1996
** SQLite for parsing.  ^These routines return 1 if the input string
1997
** appears to be a complete SQL statement.  ^A statement is judged to be
1998
** complete if it ends with a semicolon token and is not a prefix of a
1999
** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
2000
** string literals or quoted identifier names or comments are not
2001
** independent tokens (they are part of the token in which they are
2002
** embedded) and thus do not count as a statement terminator.  ^Whitespace
2003
** and comments that follow the final semicolon are ignored.
2004
**
2005
** ^These routines return 0 if the statement is incomplete.  ^If a
2006
** memory allocation fails, then SQLITE_NOMEM is returned.
2007
**
2008
** ^These routines do not parse the SQL statements thus
2009
** will not detect syntactically incorrect SQL.
2010
**
2011
** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 
2012
** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2013
** automatically by sqlite3_complete16().  If that initialization fails,
2014
** then the return value from sqlite3_complete16() will be non-zero
2015
** regardless of whether or not the input SQL is complete.)^
2016
**
2017
** The input to [sqlite3_complete()] must be a zero-terminated
2018
** UTF-8 string.
2019
**
2020
** The input to [sqlite3_complete16()] must be a zero-terminated
2021
** UTF-16 string in native byte order.
2022
*/
2023
SQLITE_API int sqlite3_complete(const char *sql);
2024
SQLITE_API int sqlite3_complete16(const void *sql);
2025

    
2026
/*
2027
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2028
**
2029
** ^This routine sets a callback function that might be invoked whenever
2030
** an attempt is made to open a database table that another thread
2031
** or process has locked.
2032
**
2033
** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
2034
** is returned immediately upon encountering the lock.  ^If the busy callback
2035
** is not NULL, then the callback might be invoked with two arguments.
2036
**
2037
** ^The first argument to the busy handler is a copy of the void* pointer which
2038
** is the third argument to sqlite3_busy_handler().  ^The second argument to
2039
** the busy handler callback is the number of times that the busy handler has
2040
** been invoked for this locking event.  ^If the
2041
** busy callback returns 0, then no additional attempts are made to
2042
** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
2043
** ^If the callback returns non-zero, then another attempt
2044
** is made to open the database for reading and the cycle repeats.
2045
**
2046
** The presence of a busy handler does not guarantee that it will be invoked
2047
** when there is lock contention. ^If SQLite determines that invoking the busy
2048
** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2049
** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
2050
** Consider a scenario where one process is holding a read lock that
2051
** it is trying to promote to a reserved lock and
2052
** a second process is holding a reserved lock that it is trying
2053
** to promote to an exclusive lock.  The first process cannot proceed
2054
** because it is blocked by the second and the second process cannot
2055
** proceed because it is blocked by the first.  If both processes
2056
** invoke the busy handlers, neither will make any progress.  Therefore,
2057
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2058
** will induce the first process to release its read lock and allow
2059
** the second process to proceed.
2060
**
2061
** ^The default busy callback is NULL.
2062
**
2063
** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
2064
** when SQLite is in the middle of a large transaction where all the
2065
** changes will not fit into the in-memory cache.  SQLite will
2066
** already hold a RESERVED lock on the database file, but it needs
2067
** to promote this lock to EXCLUSIVE so that it can spill cache
2068
** pages into the database file without harm to concurrent
2069
** readers.  ^If it is unable to promote the lock, then the in-memory
2070
** cache will be left in an inconsistent state and so the error
2071
** code is promoted from the relatively benign [SQLITE_BUSY] to
2072
** the more severe [SQLITE_IOERR_BLOCKED].  ^This error code promotion
2073
** forces an automatic rollback of the changes.  See the
2074
** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
2075
** CorruptionFollowingBusyError</a> wiki page for a discussion of why
2076
** this is important.
2077
**
2078
** ^(There can only be a single busy handler defined for each
2079
** [database connection].  Setting a new busy handler clears any
2080
** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
2081
** will also set or clear the busy handler.
2082
**
2083
** The busy callback should not take any actions which modify the
2084
** database connection that invoked the busy handler.  Any such actions
2085
** result in undefined behavior.
2086
** 
2087
** A busy handler must not close the database connection
2088
** or [prepared statement] that invoked the busy handler.
2089
*/
2090
SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
2091

    
2092
/*
2093
** CAPI3REF: Set A Busy Timeout
2094
**
2095
** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2096
** for a specified amount of time when a table is locked.  ^The handler
2097
** will sleep multiple times until at least "ms" milliseconds of sleeping
2098
** have accumulated.  ^After at least "ms" milliseconds of sleeping,
2099
** the handler returns 0 which causes [sqlite3_step()] to return
2100
** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
2101
**
2102
** ^Calling this routine with an argument less than or equal to zero
2103
** turns off all busy handlers.
2104
**
2105
** ^(There can only be a single busy handler for a particular
2106
** [database connection] any any given moment.  If another busy handler
2107
** was defined  (using [sqlite3_busy_handler()]) prior to calling
2108
** this routine, that other busy handler is cleared.)^
2109
*/
2110
SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2111

    
2112
/*
2113
** CAPI3REF: Convenience Routines For Running Queries
2114
**
2115
** This is a legacy interface that is preserved for backwards compatibility.
2116
** Use of this interface is not recommended.
2117
**
2118
** Definition: A <b>result table</b> is memory data structure created by the
2119
** [sqlite3_get_table()] interface.  A result table records the
2120
** complete query results from one or more queries.
2121
**
2122
** The table conceptually has a number of rows and columns.  But
2123
** these numbers are not part of the result table itself.  These
2124
** numbers are obtained separately.  Let N be the number of rows
2125
** and M be the number of columns.
2126
**
2127
** A result table is an array of pointers to zero-terminated UTF-8 strings.
2128
** There are (N+1)*M elements in the array.  The first M pointers point
2129
** to zero-terminated strings that  contain the names of the columns.
2130
** The remaining entries all point to query results.  NULL values result
2131
** in NULL pointers.  All other values are in their UTF-8 zero-terminated
2132
** string representation as returned by [sqlite3_column_text()].
2133
**
2134
** A result table might consist of one or more memory allocations.
2135
** It is not safe to pass a result table directly to [sqlite3_free()].
2136
** A result table should be deallocated using [sqlite3_free_table()].
2137
**
2138
** ^(As an example of the result table format, suppose a query result
2139
** is as follows:
2140
**
2141
** <blockquote><pre>
2142
**        Name        | Age
2143
**        -----------------------
2144
**        Alice       | 43
2145
**        Bob         | 28
2146
**        Cindy       | 21
2147
** </pre></blockquote>
2148
**
2149
** There are two column (M==2) and three rows (N==3).  Thus the
2150
** result table has 8 entries.  Suppose the result table is stored
2151
** in an array names azResult.  Then azResult holds this content:
2152
**
2153
** <blockquote><pre>
2154
**        azResult&#91;0] = "Name";
2155
**        azResult&#91;1] = "Age";
2156
**        azResult&#91;2] = "Alice";
2157
**        azResult&#91;3] = "43";
2158
**        azResult&#91;4] = "Bob";
2159
**        azResult&#91;5] = "28";
2160
**        azResult&#91;6] = "Cindy";
2161
**        azResult&#91;7] = "21";
2162
** </pre></blockquote>)^
2163
**
2164
** ^The sqlite3_get_table() function evaluates one or more
2165
** semicolon-separated SQL statements in the zero-terminated UTF-8
2166
** string of its 2nd parameter and returns a result table to the
2167
** pointer given in its 3rd parameter.
2168
**
2169
** After the application has finished with the result from sqlite3_get_table(),
2170
** it must pass the result table pointer to sqlite3_free_table() in order to
2171
** release the memory that was malloced.  Because of the way the
2172
** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2173
** function must not try to call [sqlite3_free()] directly.  Only
2174
** [sqlite3_free_table()] is able to release the memory properly and safely.
2175
**
2176
** The sqlite3_get_table() interface is implemented as a wrapper around
2177
** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
2178
** to any internal data structures of SQLite.  It uses only the public
2179
** interface defined here.  As a consequence, errors that occur in the
2180
** wrapper layer outside of the internal [sqlite3_exec()] call are not
2181
** reflected in subsequent calls to [sqlite3_errcode()] or
2182
** [sqlite3_errmsg()].
2183
*/
2184
SQLITE_API int sqlite3_get_table(
2185
  sqlite3 *db,          /* An open database */
2186
  const char *zSql,     /* SQL to be evaluated */
2187
  char ***pazResult,    /* Results of the query */
2188
  int *pnRow,           /* Number of result rows written here */
2189
  int *pnColumn,        /* Number of result columns written here */
2190
  char **pzErrmsg       /* Error msg written here */
2191
);
2192
SQLITE_API void sqlite3_free_table(char **result);
2193

    
2194
/*
2195
** CAPI3REF: Formatted String Printing Functions
2196
**
2197
** These routines are work-alikes of the "printf()" family of functions
2198
** from the standard C library.
2199
**
2200
** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2201
** results into memory obtained from [sqlite3_malloc()].
2202
** The strings returned by these two routines should be
2203
** released by [sqlite3_free()].  ^Both routines return a
2204
** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2205
** memory to hold the resulting string.
2206
**
2207
** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2208
** the standard C library.  The result is written into the
2209
** buffer supplied as the second parameter whose size is given by
2210
** the first parameter. Note that the order of the
2211
** first two parameters is reversed from snprintf().)^  This is an
2212
** historical accident that cannot be fixed without breaking
2213
** backwards compatibility.  ^(Note also that sqlite3_snprintf()
2214
** returns a pointer to its buffer instead of the number of
2215
** characters actually written into the buffer.)^  We admit that
2216
** the number of characters written would be a more useful return
2217
** value but we cannot change the implementation of sqlite3_snprintf()
2218
** now without breaking compatibility.
2219
**
2220
** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2221
** guarantees that the buffer is always zero-terminated.  ^The first
2222
** parameter "n" is the total size of the buffer, including space for
2223
** the zero terminator.  So the longest string that can be completely
2224
** written will be n-1 characters.
2225
**
2226
** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2227
**
2228
** These routines all implement some additional formatting
2229
** options that are useful for constructing SQL statements.
2230
** All of the usual printf() formatting options apply.  In addition, there
2231
** is are "%q", "%Q", and "%z" options.
2232
**
2233
** ^(The %q option works like %s in that it substitutes a nul-terminated
2234
** string from the argument list.  But %q also doubles every '\'' character.
2235
** %q is designed for use inside a string literal.)^  By doubling each '\''
2236
** character it escapes that character and allows it to be inserted into
2237
** the string.
2238
**
2239
** For example, assume the string variable zText contains text as follows:
2240
**
2241
** <blockquote><pre>
2242
**  char *zText = "It's a happy day!";
2243
** </pre></blockquote>
2244
**
2245
** One can use this text in an SQL statement as follows:
2246
**
2247
** <blockquote><pre>
2248
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2249
**  sqlite3_exec(db, zSQL, 0, 0, 0);
2250
**  sqlite3_free(zSQL);
2251
** </pre></blockquote>
2252
**
2253
** Because the %q format string is used, the '\'' character in zText
2254
** is escaped and the SQL generated is as follows:
2255
**
2256
** <blockquote><pre>
2257
**  INSERT INTO table1 VALUES('It''s a happy day!')
2258
** </pre></blockquote>
2259
**
2260
** This is correct.  Had we used %s instead of %q, the generated SQL
2261
** would have looked like this:
2262
**
2263
** <blockquote><pre>
2264
**  INSERT INTO table1 VALUES('It's a happy day!');
2265
** </pre></blockquote>
2266
**
2267
** This second example is an SQL syntax error.  As a general rule you should
2268
** always use %q instead of %s when inserting text into a string literal.
2269
**
2270
** ^(The %Q option works like %q except it also adds single quotes around
2271
** the outside of the total string.  Additionally, if the parameter in the
2272
** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2273
** single quotes).)^  So, for example, one could say:
2274
**
2275
** <blockquote><pre>
2276
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2277
**  sqlite3_exec(db, zSQL, 0, 0, 0);
2278
**  sqlite3_free(zSQL);
2279
** </pre></blockquote>
2280
**
2281
** The code above will render a correct SQL statement in the zSQL
2282
** variable even if the zText variable is a NULL pointer.
2283
**
2284
** ^(The "%z" formatting option works like "%s" but with the
2285
** addition that after the string has been read and copied into
2286
** the result, [sqlite3_free()] is called on the input string.)^
2287
*/
2288
SQLITE_API char *sqlite3_mprintf(const char*,...);
2289
SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2290
SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2291
SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2292

    
2293
/*
2294
** CAPI3REF: Memory Allocation Subsystem
2295
**
2296
** The SQLite core uses these three routines for all of its own
2297
** internal memory allocation needs. "Core" in the previous sentence
2298
** does not include operating-system specific VFS implementation.  The
2299
** Windows VFS uses native malloc() and free() for some operations.
2300
**
2301
** ^The sqlite3_malloc() routine returns a pointer to a block
2302
** of memory at least N bytes in length, where N is the parameter.
2303
** ^If sqlite3_malloc() is unable to obtain sufficient free
2304
** memory, it returns a NULL pointer.  ^If the parameter N to
2305
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2306
** a NULL pointer.
2307
**
2308
** ^Calling sqlite3_free() with a pointer previously returned
2309
** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2310
** that it might be reused.  ^The sqlite3_free() routine is
2311
** a no-op if is called with a NULL pointer.  Passing a NULL pointer
2312
** to sqlite3_free() is harmless.  After being freed, memory
2313
** should neither be read nor written.  Even reading previously freed
2314
** memory might result in a segmentation fault or other severe error.
2315
** Memory corruption, a segmentation fault, or other severe error
2316
** might result if sqlite3_free() is called with a non-NULL pointer that
2317
** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2318
**
2319
** ^(The sqlite3_realloc() interface attempts to resize a
2320
** prior memory allocation to be at least N bytes, where N is the
2321
** second parameter.  The memory allocation to be resized is the first
2322
** parameter.)^ ^ If the first parameter to sqlite3_realloc()
2323
** is a NULL pointer then its behavior is identical to calling
2324
** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
2325
** ^If the second parameter to sqlite3_realloc() is zero or
2326
** negative then the behavior is exactly the same as calling
2327
** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
2328
** ^sqlite3_realloc() returns a pointer to a memory allocation
2329
** of at least N bytes in size or NULL if sufficient memory is unavailable.
2330
** ^If M is the size of the prior allocation, then min(N,M) bytes
2331
** of the prior allocation are copied into the beginning of buffer returned
2332
** by sqlite3_realloc() and the prior allocation is freed.
2333
** ^If sqlite3_realloc() returns NULL, then the prior allocation
2334
** is not freed.
2335
**
2336
** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
2337
** is always aligned to at least an 8 byte boundary, or to a
2338
** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2339
** option is used.
2340
**
2341
** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2342
** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2343
** implementation of these routines to be omitted.  That capability
2344
** is no longer provided.  Only built-in memory allocators can be used.
2345
**
2346
** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2347
** the system malloc() and free() directly when converting
2348
** filenames between the UTF-8 encoding used by SQLite
2349
** and whatever filename encoding is used by the particular Windows
2350
** installation.  Memory allocation errors were detected, but
2351
** they were reported back as [SQLITE_CANTOPEN] or
2352
** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2353
**
2354
** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2355
** must be either NULL or else pointers obtained from a prior
2356
** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2357
** not yet been released.
2358
**
2359
** The application must not read or write any part of
2360
** a block of memory after it has been released using
2361
** [sqlite3_free()] or [sqlite3_realloc()].
2362
*/
2363
SQLITE_API void *sqlite3_malloc(int);
2364
SQLITE_API void *sqlite3_realloc(void*, int);
2365
SQLITE_API void sqlite3_free(void*);
2366

    
2367
/*
2368
** CAPI3REF: Memory Allocator Statistics
2369
**
2370
** SQLite provides these two interfaces for reporting on the status
2371
** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2372
** routines, which form the built-in memory allocation subsystem.
2373
**
2374
** ^The [sqlite3_memory_used()] routine returns the number of bytes
2375
** of memory currently outstanding (malloced but not freed).
2376
** ^The [sqlite3_memory_highwater()] routine returns the maximum
2377
** value of [sqlite3_memory_used()] since the high-water mark
2378
** was last reset.  ^The values returned by [sqlite3_memory_used()] and
2379
** [sqlite3_memory_highwater()] include any overhead
2380
** added by SQLite in its implementation of [sqlite3_malloc()],
2381
** but not overhead added by the any underlying system library
2382
** routines that [sqlite3_malloc()] may call.
2383
**
2384
** ^The memory high-water mark is reset to the current value of
2385
** [sqlite3_memory_used()] if and only if the parameter to
2386
** [sqlite3_memory_highwater()] is true.  ^The value returned
2387
** by [sqlite3_memory_highwater(1)] is the high-water mark
2388
** prior to the reset.
2389
*/
2390
SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2391
SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2392

    
2393
/*
2394
** CAPI3REF: Pseudo-Random Number Generator
2395
**
2396
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2397
** select random [ROWID | ROWIDs] when inserting new records into a table that
2398
** already uses the largest possible [ROWID].  The PRNG is also used for
2399
** the build-in random() and randomblob() SQL functions.  This interface allows
2400
** applications to access the same PRNG for other purposes.
2401
**
2402
** ^A call to this routine stores N bytes of randomness into buffer P.
2403
** ^If N is less than one, then P can be a NULL pointer.
2404
**
2405
** ^If this routine has not been previously called or if the previous
2406
** call had N less than one, then the PRNG is seeded using randomness
2407
** obtained from the xRandomness method of the default [sqlite3_vfs] object.
2408
** ^If the previous call to this routine had an N of 1 or more then
2409
** the pseudo-randomness is generated
2410
** internally and without recourse to the [sqlite3_vfs] xRandomness
2411
** method.
2412
*/
2413
SQLITE_API void sqlite3_randomness(int N, void *P);
2414

    
2415
/*
2416
** CAPI3REF: Compile-Time Authorization Callbacks
2417
**
2418
** ^This routine registers an authorizer callback with a particular
2419
** [database connection], supplied in the first argument.
2420
** ^The authorizer callback is invoked as SQL statements are being compiled
2421
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2422
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
2423
** points during the compilation process, as logic is being created
2424
** to perform various actions, the authorizer callback is invoked to
2425
** see if those actions are allowed.  ^The authorizer callback should
2426
** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2427
** specific action but allow the SQL statement to continue to be
2428
** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2429
** rejected with an error.  ^If the authorizer callback returns
2430
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2431
** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2432
** the authorizer will fail with an error message.
2433
**
2434
** When the callback returns [SQLITE_OK], that means the operation
2435
** requested is ok.  ^When the callback returns [SQLITE_DENY], the
2436
** [sqlite3_prepare_v2()] or equivalent call that triggered the
2437
** authorizer will fail with an error message explaining that
2438
** access is denied. 
2439
**
2440
** ^The first parameter to the authorizer callback is a copy of the third
2441
** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2442
** to the callback is an integer [SQLITE_COPY | action code] that specifies
2443
** the particular action to be authorized. ^The third through sixth parameters
2444
** to the callback are zero-terminated strings that contain additional
2445
** details about the action to be authorized.
2446
**
2447
** ^If the action code is [SQLITE_READ]
2448
** and the callback returns [SQLITE_IGNORE] then the
2449
** [prepared statement] statement is constructed to substitute
2450
** a NULL value in place of the table column that would have
2451
** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
2452
** return can be used to deny an untrusted user access to individual
2453
** columns of a table.
2454
** ^If the action code is [SQLITE_DELETE] and the callback returns
2455
** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2456
** [truncate optimization] is disabled and all rows are deleted individually.
2457
**
2458
** An authorizer is used when [sqlite3_prepare | preparing]
2459
** SQL statements from an untrusted source, to ensure that the SQL statements
2460
** do not try to access data they are not allowed to see, or that they do not
2461
** try to execute malicious statements that damage the database.  For
2462
** example, an application may allow a user to enter arbitrary
2463
** SQL queries for evaluation by a database.  But the application does
2464
** not want the user to be able to make arbitrary changes to the
2465
** database.  An authorizer could then be put in place while the
2466
** user-entered SQL is being [sqlite3_prepare | prepared] that
2467
** disallows everything except [SELECT] statements.
2468
**
2469
** Applications that need to process SQL from untrusted sources
2470
** might also consider lowering resource limits using [sqlite3_limit()]
2471
** and limiting database size using the [max_page_count] [PRAGMA]
2472
** in addition to using an authorizer.
2473
**
2474
** ^(Only a single authorizer can be in place on a database connection
2475
** at a time.  Each call to sqlite3_set_authorizer overrides the
2476
** previous call.)^  ^Disable the authorizer by installing a NULL callback.
2477
** The authorizer is disabled by default.
2478
**
2479
** The authorizer callback must not do anything that will modify
2480
** the database connection that invoked the authorizer callback.
2481
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2482
** database connections for the meaning of "modify" in this paragraph.
2483
**
2484
** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2485
** statement might be re-prepared during [sqlite3_step()] due to a 
2486
** schema change.  Hence, the application should ensure that the
2487
** correct authorizer callback remains in place during the [sqlite3_step()].
2488
**
2489
** ^Note that the authorizer callback is invoked only during
2490
** [sqlite3_prepare()] or its variants.  Authorization is not
2491
** performed during statement evaluation in [sqlite3_step()], unless
2492
** as stated in the previous paragraph, sqlite3_step() invokes
2493
** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2494
*/
2495
SQLITE_API int sqlite3_set_authorizer(
2496
  sqlite3*,
2497
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2498
  void *pUserData
2499
);
2500

    
2501
/*
2502
** CAPI3REF: Authorizer Return Codes
2503
**
2504
** The [sqlite3_set_authorizer | authorizer callback function] must
2505
** return either [SQLITE_OK] or one of these two constants in order
2506
** to signal SQLite whether or not the action is permitted.  See the
2507
** [sqlite3_set_authorizer | authorizer documentation] for additional
2508
** information.
2509
**
2510
** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
2511
** from the [sqlite3_vtab_on_conflict()] interface.
2512
*/
2513
#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
2514
#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
2515

    
2516
/*
2517
** CAPI3REF: Authorizer Action Codes
2518
**
2519
** The [sqlite3_set_authorizer()] interface registers a callback function
2520
** that is invoked to authorize certain SQL statement actions.  The
2521
** second parameter to the callback is an integer code that specifies
2522
** what action is being authorized.  These are the integer action codes that
2523
** the authorizer callback may be passed.
2524
**
2525
** These action code values signify what kind of operation is to be
2526
** authorized.  The 3rd and 4th parameters to the authorization
2527
** callback function will be parameters or NULL depending on which of these
2528
** codes is used as the second parameter.  ^(The 5th parameter to the
2529
** authorizer callback is the name of the database ("main", "temp",
2530
** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
2531
** is the name of the inner-most trigger or view that is responsible for
2532
** the access attempt or NULL if this access attempt is directly from
2533
** top-level SQL code.
2534
*/
2535
/******************************************* 3rd ************ 4th ***********/
2536
#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
2537
#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
2538
#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
2539
#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
2540
#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
2541
#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
2542
#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
2543
#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
2544
#define SQLITE_DELETE                9   /* Table Name      NULL            */
2545
#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
2546
#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
2547
#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
2548
#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
2549
#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
2550
#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
2551
#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
2552
#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
2553
#define SQLITE_INSERT               18   /* Table Name      NULL            */
2554
#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
2555
#define SQLITE_READ                 20   /* Table Name      Column Name     */
2556
#define SQLITE_SELECT               21   /* NULL            NULL            */
2557
#define SQLITE_TRANSACTION          22   /* Operation       NULL            */
2558
#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
2559
#define SQLITE_ATTACH               24   /* Filename        NULL            */
2560
#define SQLITE_DETACH               25   /* Database Name   NULL            */
2561
#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
2562
#define SQLITE_REINDEX              27   /* Index Name      NULL            */
2563
#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
2564
#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
2565
#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
2566
#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
2567
#define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
2568
#define SQLITE_COPY                  0   /* No longer used */
2569
#define SQLITE_RECURSIVE            33   /* NULL            NULL            */
2570

    
2571
/*
2572
** CAPI3REF: Tracing And Profiling Functions
2573
**
2574
** These routines register callback functions that can be used for
2575
** tracing and profiling the execution of SQL statements.
2576
**
2577
** ^The callback function registered by sqlite3_trace() is invoked at
2578
** various times when an SQL statement is being run by [sqlite3_step()].
2579
** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2580
** SQL statement text as the statement first begins executing.
2581
** ^(Additional sqlite3_trace() callbacks might occur
2582
** as each triggered subprogram is entered.  The callbacks for triggers
2583
** contain a UTF-8 SQL comment that identifies the trigger.)^
2584
**
2585
** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2586
** the length of [bound parameter] expansion in the output of sqlite3_trace().
2587
**
2588
** ^The callback function registered by sqlite3_profile() is invoked
2589
** as each SQL statement finishes.  ^The profile callback contains
2590
** the original statement text and an estimate of wall-clock time
2591
** of how long that statement took to run.  ^The profile callback
2592
** time is in units of nanoseconds, however the current implementation
2593
** is only capable of millisecond resolution so the six least significant
2594
** digits in the time are meaningless.  Future versions of SQLite
2595
** might provide greater resolution on the profiler callback.  The
2596
** sqlite3_profile() function is considered experimental and is
2597
** subject to change in future versions of SQLite.
2598
*/
2599
SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2600
SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
2601
   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2602

    
2603
/*
2604
** CAPI3REF: Query Progress Callbacks
2605
**
2606
** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2607
** function X to be invoked periodically during long running calls to
2608
** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2609
** database connection D.  An example use for this
2610
** interface is to keep a GUI updated during a large query.
2611
**
2612
** ^The parameter P is passed through as the only parameter to the 
2613
** callback function X.  ^The parameter N is the approximate number of 
2614
** [virtual machine instructions] that are evaluated between successive
2615
** invocations of the callback X.  ^If N is less than one then the progress
2616
** handler is disabled.
2617
**
2618
** ^Only a single progress handler may be defined at one time per
2619
** [database connection]; setting a new progress handler cancels the
2620
** old one.  ^Setting parameter X to NULL disables the progress handler.
2621
** ^The progress handler is also disabled by setting N to a value less
2622
** than 1.
2623
**
2624
** ^If the progress callback returns non-zero, the operation is
2625
** interrupted.  This feature can be used to implement a
2626
** "Cancel" button on a GUI progress dialog box.
2627
**
2628
** The progress handler callback must not do anything that will modify
2629
** the database connection that invoked the progress handler.
2630
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2631
** database connections for the meaning of "modify" in this paragraph.
2632
**
2633
*/
2634
SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2635

    
2636
/*
2637
** CAPI3REF: Opening A New Database Connection
2638
**
2639
** ^These routines open an SQLite database file as specified by the 
2640
** filename argument. ^The filename argument is interpreted as UTF-8 for
2641
** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2642
** order for sqlite3_open16(). ^(A [database connection] handle is usually
2643
** returned in *ppDb, even if an error occurs.  The only exception is that
2644
** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2645
** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2646
** object.)^ ^(If the database is opened (and/or created) successfully, then
2647
** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
2648
** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2649
** an English language description of the error following a failure of any
2650
** of the sqlite3_open() routines.
2651
**
2652
** ^The default encoding for the database will be UTF-8 if
2653
** sqlite3_open() or sqlite3_open_v2() is called and
2654
** UTF-16 in the native byte order if sqlite3_open16() is used.
2655
**
2656
** Whether or not an error occurs when it is opened, resources
2657
** associated with the [database connection] handle should be released by
2658
** passing it to [sqlite3_close()] when it is no longer required.
2659
**
2660
** The sqlite3_open_v2() interface works like sqlite3_open()
2661
** except that it accepts two additional parameters for additional control
2662
** over the new database connection.  ^(The flags parameter to
2663
** sqlite3_open_v2() can take one of
2664
** the following three values, optionally combined with the 
2665
** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
2666
** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
2667
**
2668
** <dl>
2669
** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
2670
** <dd>The database is opened in read-only mode.  If the database does not
2671
** already exist, an error is returned.</dd>)^
2672
**
2673
** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
2674
** <dd>The database is opened for reading and writing if possible, or reading
2675
** only if the file is write protected by the operating system.  In either
2676
** case the database must already exist, otherwise an error is returned.</dd>)^
2677
**
2678
** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
2679
** <dd>The database is opened for reading and writing, and is created if
2680
** it does not already exist. This is the behavior that is always used for
2681
** sqlite3_open() and sqlite3_open16().</dd>)^
2682
** </dl>
2683
**
2684
** If the 3rd parameter to sqlite3_open_v2() is not one of the
2685
** combinations shown above optionally combined with other
2686
** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
2687
** then the behavior is undefined.
2688
**
2689
** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
2690
** opens in the multi-thread [threading mode] as long as the single-thread
2691
** mode has not been set at compile-time or start-time.  ^If the
2692
** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2693
** in the serialized [threading mode] unless single-thread was
2694
** previously selected at compile-time or start-time.
2695
** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
2696
** eligible to use [shared cache mode], regardless of whether or not shared
2697
** cache is enabled using [sqlite3_enable_shared_cache()].  ^The
2698
** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2699
** participate in [shared cache mode] even if it is enabled.
2700
**
2701
** ^The fourth parameter to sqlite3_open_v2() is the name of the
2702
** [sqlite3_vfs] object that defines the operating system interface that
2703
** the new database connection should use.  ^If the fourth parameter is
2704
** a NULL pointer then the default [sqlite3_vfs] object is used.
2705
**
2706
** ^If the filename is ":memory:", then a private, temporary in-memory database
2707
** is created for the connection.  ^This in-memory database will vanish when
2708
** the database connection is closed.  Future versions of SQLite might
2709
** make use of additional special filenames that begin with the ":" character.
2710
** It is recommended that when a database filename actually does begin with
2711
** a ":" character you should prefix the filename with a pathname such as
2712
** "./" to avoid ambiguity.
2713
**
2714
** ^If the filename is an empty string, then a private, temporary
2715
** on-disk database will be created.  ^This private database will be
2716
** automatically deleted as soon as the database connection is closed.
2717
**
2718
** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
2719
**
2720
** ^If [URI filename] interpretation is enabled, and the filename argument
2721
** begins with "file:", then the filename is interpreted as a URI. ^URI
2722
** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
2723
** set in the fourth argument to sqlite3_open_v2(), or if it has
2724
** been enabled globally using the [SQLITE_CONFIG_URI] option with the
2725
** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
2726
** As of SQLite version 3.7.7, URI filename interpretation is turned off
2727
** by default, but future releases of SQLite might enable URI filename
2728
** interpretation by default.  See "[URI filenames]" for additional
2729
** information.
2730
**
2731
** URI filenames are parsed according to RFC 3986. ^If the URI contains an
2732
** authority, then it must be either an empty string or the string 
2733
** "localhost". ^If the authority is not an empty string or "localhost", an 
2734
** error is returned to the caller. ^The fragment component of a URI, if 
2735
** present, is ignored.
2736
**
2737
** ^SQLite uses the path component of the URI as the name of the disk file
2738
** which contains the database. ^If the path begins with a '/' character, 
2739
** then it is interpreted as an absolute path. ^If the path does not begin 
2740
** with a '/' (meaning that the authority section is omitted from the URI)
2741
** then the path is interpreted as a relative path. 
2742
** ^On windows, the first component of an absolute path 
2743
** is a drive specification (e.g. "C:").
2744
**
2745
** [[core URI query parameters]]
2746
** The query component of a URI may contain parameters that are interpreted
2747
** either by SQLite itself, or by a [VFS | custom VFS implementation].
2748
** SQLite interprets the following three query parameters:
2749
**
2750
** <ul>
2751
**   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
2752
**     a VFS object that provides the operating system interface that should
2753
**     be used to access the database file on disk. ^If this option is set to
2754
**     an empty string the default VFS object is used. ^Specifying an unknown
2755
**     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
2756
**     present, then the VFS specified by the option takes precedence over
2757
**     the value passed as the fourth parameter to sqlite3_open_v2().
2758
**
2759
**   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
2760
**     "rwc", or "memory". Attempting to set it to any other value is
2761
**     an error)^. 
2762
**     ^If "ro" is specified, then the database is opened for read-only 
2763
**     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 
2764
**     third argument to sqlite3_open_v2(). ^If the mode option is set to 
2765
**     "rw", then the database is opened for read-write (but not create) 
2766
**     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 
2767
**     been set. ^Value "rwc" is equivalent to setting both 
2768
**     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE.  ^If the mode option is
2769
**     set to "memory" then a pure [in-memory database] that never reads
2770
**     or writes from disk is used. ^It is an error to specify a value for
2771
**     the mode parameter that is less restrictive than that specified by
2772
**     the flags passed in the third parameter to sqlite3_open_v2().
2773
**
2774
**   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
2775
**     "private". ^Setting it to "shared" is equivalent to setting the
2776
**     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
2777
**     sqlite3_open_v2(). ^Setting the cache parameter to "private" is 
2778
**     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
2779
**     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
2780
**     a URI filename, its value overrides any behavior requested by setting
2781
**     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
2782
** </ul>
2783
**
2784
** ^Specifying an unknown parameter in the query component of a URI is not an
2785
** error.  Future versions of SQLite might understand additional query
2786
** parameters.  See "[query parameters with special meaning to SQLite]" for
2787
** additional information.
2788
**
2789
** [[URI filename examples]] <h3>URI filename examples</h3>
2790
**
2791
** <table border="1" align=center cellpadding=5>
2792
** <tr><th> URI filenames <th> Results
2793
** <tr><td> file:data.db <td> 
2794
**          Open the file "data.db" in the current directory.
2795
** <tr><td> file:/home/fred/data.db<br>
2796
**          file:///home/fred/data.db <br> 
2797
**          file://localhost/home/fred/data.db <br> <td> 
2798
**          Open the database file "/home/fred/data.db".
2799
** <tr><td> file://darkstar/home/fred/data.db <td> 
2800
**          An error. "darkstar" is not a recognized authority.
2801
** <tr><td style="white-space:nowrap"> 
2802
**          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
2803
**     <td> Windows only: Open the file "data.db" on fred's desktop on drive
2804
**          C:. Note that the %20 escaping in this example is not strictly 
2805
**          necessary - space characters can be used literally
2806
**          in URI filenames.
2807
** <tr><td> file:data.db?mode=ro&cache=private <td> 
2808
**          Open file "data.db" in the current directory for read-only access.
2809
**          Regardless of whether or not shared-cache mode is enabled by
2810
**          default, use a private cache.
2811
** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
2812
**          Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
2813
** <tr><td> file:data.db?mode=readonly <td> 
2814
**          An error. "readonly" is not a valid option for the "mode" parameter.
2815
** </table>
2816
**
2817
** ^URI hexadecimal escape sequences (%HH) are supported within the path and
2818
** query components of a URI. A hexadecimal escape sequence consists of a
2819
** percent sign - "%" - followed by exactly two hexadecimal digits 
2820
** specifying an octet value. ^Before the path or query components of a
2821
** URI filename are interpreted, they are encoded using UTF-8 and all 
2822
** hexadecimal escape sequences replaced by a single byte containing the
2823
** corresponding octet. If this process generates an invalid UTF-8 encoding,
2824
** the results are undefined.
2825
**
2826
** <b>Note to Windows users:</b>  The encoding used for the filename argument
2827
** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
2828
** codepage is currently defined.  Filenames containing international
2829
** characters must be converted to UTF-8 prior to passing them into
2830
** sqlite3_open() or sqlite3_open_v2().
2831
**
2832
** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
2833
** prior to calling sqlite3_open() or sqlite3_open_v2().  Otherwise, various
2834
** features that require the use of temporary files may fail.
2835
**
2836
** See also: [sqlite3_temp_directory]
2837
*/
2838
SQLITE_API int sqlite3_open(
2839
  const char *filename,   /* Database filename (UTF-8) */
2840
  sqlite3 **ppDb          /* OUT: SQLite db handle */
2841
);
2842
SQLITE_API int sqlite3_open16(
2843
  const void *filename,   /* Database filename (UTF-16) */
2844
  sqlite3 **ppDb          /* OUT: SQLite db handle */
2845
);
2846
SQLITE_API int sqlite3_open_v2(
2847
  const char *filename,   /* Database filename (UTF-8) */
2848
  sqlite3 **ppDb,         /* OUT: SQLite db handle */
2849
  int flags,              /* Flags */
2850
  const char *zVfs        /* Name of VFS module to use */
2851
);
2852

    
2853
/*
2854
** CAPI3REF: Obtain Values For URI Parameters
2855
**
2856
** These are utility routines, useful to VFS implementations, that check
2857
** to see if a database file was a URI that contained a specific query 
2858
** parameter, and if so obtains the value of that query parameter.
2859
**
2860
** If F is the database filename pointer passed into the xOpen() method of 
2861
** a VFS implementation when the flags parameter to xOpen() has one or 
2862
** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
2863
** P is the name of the query parameter, then
2864
** sqlite3_uri_parameter(F,P) returns the value of the P
2865
** parameter if it exists or a NULL pointer if P does not appear as a 
2866
** query parameter on F.  If P is a query parameter of F
2867
** has no explicit value, then sqlite3_uri_parameter(F,P) returns
2868
** a pointer to an empty string.
2869
**
2870
** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
2871
** parameter and returns true (1) or false (0) according to the value
2872
** of P.  The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
2873
** value of query parameter P is one of "yes", "true", or "on" in any
2874
** case or if the value begins with a non-zero number.  The 
2875
** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
2876
** query parameter P is one of "no", "false", or "off" in any case or
2877
** if the value begins with a numeric zero.  If P is not a query
2878
** parameter on F or if the value of P is does not match any of the
2879
** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
2880
**
2881
** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
2882
** 64-bit signed integer and returns that integer, or D if P does not
2883
** exist.  If the value of P is something other than an integer, then
2884
** zero is returned.
2885
** 
2886
** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
2887
** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
2888
** is not a database file pathname pointer that SQLite passed into the xOpen
2889
** VFS method, then the behavior of this routine is undefined and probably
2890
** undesirable.
2891
*/
2892
SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
2893
SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
2894
SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
2895

    
2896

    
2897
/*
2898
** CAPI3REF: Error Codes And Messages
2899
**
2900
** ^The sqlite3_errcode() interface returns the numeric [result code] or
2901
** [extended result code] for the most recent failed sqlite3_* API call
2902
** associated with a [database connection]. If a prior API call failed
2903
** but the most recent API call succeeded, the return value from
2904
** sqlite3_errcode() is undefined.  ^The sqlite3_extended_errcode()
2905
** interface is the same except that it always returns the 
2906
** [extended result code] even when extended result codes are
2907
** disabled.
2908
**
2909
** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
2910
** text that describes the error, as either UTF-8 or UTF-16 respectively.
2911
** ^(Memory to hold the error message string is managed internally.
2912
** The application does not need to worry about freeing the result.
2913
** However, the error string might be overwritten or deallocated by
2914
** subsequent calls to other SQLite interface functions.)^
2915
**
2916
** ^The sqlite3_errstr() interface returns the English-language text
2917
** that describes the [result code], as UTF-8.
2918
** ^(Memory to hold the error message string is managed internally
2919
** and must not be freed by the application)^.
2920
**
2921
** When the serialized [threading mode] is in use, it might be the
2922
** case that a second error occurs on a separate thread in between
2923
** the time of the first error and the call to these interfaces.
2924
** When that happens, the second error will be reported since these
2925
** interfaces always report the most recent result.  To avoid
2926
** this, each thread can obtain exclusive use of the [database connection] D
2927
** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
2928
** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
2929
** all calls to the interfaces listed here are completed.
2930
**
2931
** If an interface fails with SQLITE_MISUSE, that means the interface
2932
** was invoked incorrectly by the application.  In that case, the
2933
** error code and message may or may not be set.
2934
*/
2935
SQLITE_API int sqlite3_errcode(sqlite3 *db);
2936
SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
2937
SQLITE_API const char *sqlite3_errmsg(sqlite3*);
2938
SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
2939
SQLITE_API const char *sqlite3_errstr(int);
2940

    
2941
/*
2942
** CAPI3REF: SQL Statement Object
2943
** KEYWORDS: {prepared statement} {prepared statements}
2944
**
2945
** An instance of this object represents a single SQL statement.
2946
** This object is variously known as a "prepared statement" or a
2947
** "compiled SQL statement" or simply as a "statement".
2948
**
2949
** The life of a statement object goes something like this:
2950
**
2951
** <ol>
2952
** <li> Create the object using [sqlite3_prepare_v2()] or a related
2953
**      function.
2954
** <li> Bind values to [host parameters] using the sqlite3_bind_*()
2955
**      interfaces.
2956
** <li> Run the SQL by calling [sqlite3_step()] one or more times.
2957
** <li> Reset the statement using [sqlite3_reset()] then go back
2958
**      to step 2.  Do this zero or more times.
2959
** <li> Destroy the object using [sqlite3_finalize()].
2960
** </ol>
2961
**
2962
** Refer to documentation on individual methods above for additional
2963
** information.
2964
*/
2965
typedef struct sqlite3_stmt sqlite3_stmt;
2966

    
2967
/*
2968
** CAPI3REF: Run-time Limits
2969
**
2970
** ^(This interface allows the size of various constructs to be limited
2971
** on a connection by connection basis.  The first parameter is the
2972
** [database connection] whose limit is to be set or queried.  The
2973
** second parameter is one of the [limit categories] that define a
2974
** class of constructs to be size limited.  The third parameter is the
2975
** new limit for that construct.)^
2976
**
2977
** ^If the new limit is a negative number, the limit is unchanged.
2978
** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 
2979
** [limits | hard upper bound]
2980
** set at compile-time by a C preprocessor macro called
2981
** [limits | SQLITE_MAX_<i>NAME</i>].
2982
** (The "_LIMIT_" in the name is changed to "_MAX_".))^
2983
** ^Attempts to increase a limit above its hard upper bound are
2984
** silently truncated to the hard upper bound.
2985
**
2986
** ^Regardless of whether or not the limit was changed, the 
2987
** [sqlite3_limit()] interface returns the prior value of the limit.
2988
** ^Hence, to find the current value of a limit without changing it,
2989
** simply invoke this interface with the third parameter set to -1.
2990
**
2991
** Run-time limits are intended for use in applications that manage
2992
** both their own internal database and also databases that are controlled
2993
** by untrusted external sources.  An example application might be a
2994
** web browser that has its own databases for storing history and
2995
** separate databases controlled by JavaScript applications downloaded
2996
** off the Internet.  The internal databases can be given the
2997
** large, default limits.  Databases managed by external sources can
2998
** be given much smaller limits designed to prevent a denial of service
2999
** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
3000
** interface to further control untrusted SQL.  The size of the database
3001
** created by an untrusted script can be contained using the
3002
** [max_page_count] [PRAGMA].
3003
**
3004
** New run-time limit categories may be added in future releases.
3005
*/
3006
SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3007

    
3008
/*
3009
** CAPI3REF: Run-Time Limit Categories
3010
** KEYWORDS: {limit category} {*limit categories}
3011
**
3012
** These constants define various performance limits
3013
** that can be lowered at run-time using [sqlite3_limit()].
3014
** The synopsis of the meanings of the various limits is shown below.
3015
** Additional information is available at [limits | Limits in SQLite].
3016
**
3017
** <dl>
3018
** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3019
** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3020
**
3021
** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3022
** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3023
**
3024
** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3025
** <dd>The maximum number of columns in a table definition or in the
3026
** result set of a [SELECT] or the maximum number of columns in an index
3027
** or in an ORDER BY or GROUP BY clause.</dd>)^
3028
**
3029
** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3030
** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3031
**
3032
** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3033
** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3034
**
3035
** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3036
** <dd>The maximum number of instructions in a virtual machine program
3037
** used to implement an SQL statement.  This limit is not currently
3038
** enforced, though that might be added in some future release of
3039
** SQLite.</dd>)^
3040
**
3041
** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3042
** <dd>The maximum number of arguments on a function.</dd>)^
3043
**
3044
** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3045
** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3046
**
3047
** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3048
** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3049
** <dd>The maximum length of the pattern argument to the [LIKE] or
3050
** [GLOB] operators.</dd>)^
3051
**
3052
** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3053
** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3054
** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3055
**
3056
** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3057
** <dd>The maximum depth of recursion for triggers.</dd>)^
3058
** </dl>
3059
*/
3060
#define SQLITE_LIMIT_LENGTH                    0
3061
#define SQLITE_LIMIT_SQL_LENGTH                1
3062
#define SQLITE_LIMIT_COLUMN                    2
3063
#define SQLITE_LIMIT_EXPR_DEPTH                3
3064
#define SQLITE_LIMIT_COMPOUND_SELECT           4
3065
#define SQLITE_LIMIT_VDBE_OP                   5
3066
#define SQLITE_LIMIT_FUNCTION_ARG              6
3067
#define SQLITE_LIMIT_ATTACHED                  7
3068
#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
3069
#define SQLITE_LIMIT_VARIABLE_NUMBER           9
3070
#define SQLITE_LIMIT_TRIGGER_DEPTH            10
3071

    
3072
/*
3073
** CAPI3REF: Compiling An SQL Statement
3074
** KEYWORDS: {SQL statement compiler}
3075
**
3076
** To execute an SQL query, it must first be compiled into a byte-code
3077
** program using one of these routines.
3078
**
3079
** The first argument, "db", is a [database connection] obtained from a
3080
** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3081
** [sqlite3_open16()].  The database connection must not have been closed.
3082
**
3083
** The second argument, "zSql", is the statement to be compiled, encoded
3084
** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
3085
** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
3086
** use UTF-16.
3087
**
3088
** ^If the nByte argument is less than zero, then zSql is read up to the
3089
** first zero terminator. ^If nByte is non-negative, then it is the maximum
3090
** number of  bytes read from zSql.  ^When nByte is non-negative, the
3091
** zSql string ends at either the first '\000' or '\u0000' character or
3092
** the nByte-th byte, whichever comes first. If the caller knows
3093
** that the supplied string is nul-terminated, then there is a small
3094
** performance advantage to be gained by passing an nByte parameter that
3095
** is equal to the number of bytes in the input string <i>including</i>
3096
** the nul-terminator bytes as this saves SQLite from having to
3097
** make a copy of the input string.
3098
**
3099
** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3100
** past the end of the first SQL statement in zSql.  These routines only
3101
** compile the first statement in zSql, so *pzTail is left pointing to
3102
** what remains uncompiled.
3103
**
3104
** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3105
** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
3106
** to NULL.  ^If the input text contains no SQL (if the input is an empty
3107
** string or a comment) then *ppStmt is set to NULL.
3108
** The calling procedure is responsible for deleting the compiled
3109
** SQL statement using [sqlite3_finalize()] after it has finished with it.
3110
** ppStmt may not be NULL.
3111
**
3112
** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3113
** otherwise an [error code] is returned.
3114
**
3115
** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
3116
** recommended for all new programs. The two older interfaces are retained
3117
** for backwards compatibility, but their use is discouraged.
3118
** ^In the "v2" interfaces, the prepared statement
3119
** that is returned (the [sqlite3_stmt] object) contains a copy of the
3120
** original SQL text. This causes the [sqlite3_step()] interface to
3121
** behave differently in three ways:
3122
**
3123
** <ol>
3124
** <li>
3125
** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3126
** always used to do, [sqlite3_step()] will automatically recompile the SQL
3127
** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3128
** retries will occur before sqlite3_step() gives up and returns an error.
3129
** </li>
3130
**
3131
** <li>
3132
** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3133
** [error codes] or [extended error codes].  ^The legacy behavior was that
3134
** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3135
** and the application would have to make a second call to [sqlite3_reset()]
3136
** in order to find the underlying cause of the problem. With the "v2" prepare
3137
** interfaces, the underlying reason for the error is returned immediately.
3138
** </li>
3139
**
3140
** <li>
3141
** ^If the specific value bound to [parameter | host parameter] in the 
3142
** WHERE clause might influence the choice of query plan for a statement,
3143
** then the statement will be automatically recompiled, as if there had been 
3144
** a schema change, on the first  [sqlite3_step()] call following any change
3145
** to the [sqlite3_bind_text | bindings] of that [parameter]. 
3146
** ^The specific value of WHERE-clause [parameter] might influence the 
3147
** choice of query plan if the parameter is the left-hand side of a [LIKE]
3148
** or [GLOB] operator or if the parameter is compared to an indexed column
3149
** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3150
** </li>
3151
** </ol>
3152
*/
3153
SQLITE_API int sqlite3_prepare(
3154
  sqlite3 *db,            /* Database handle */
3155
  const char *zSql,       /* SQL statement, UTF-8 encoded */
3156
  int nByte,              /* Maximum length of zSql in bytes. */
3157
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3158
  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3159
);
3160
SQLITE_API int sqlite3_prepare_v2(
3161
  sqlite3 *db,            /* Database handle */
3162
  const char *zSql,       /* SQL statement, UTF-8 encoded */
3163
  int nByte,              /* Maximum length of zSql in bytes. */
3164
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3165
  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3166
);
3167
SQLITE_API int sqlite3_prepare16(
3168
  sqlite3 *db,            /* Database handle */
3169
  const void *zSql,       /* SQL statement, UTF-16 encoded */
3170
  int nByte,              /* Maximum length of zSql in bytes. */
3171
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3172
  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3173
);
3174
SQLITE_API int sqlite3_prepare16_v2(
3175
  sqlite3 *db,            /* Database handle */
3176
  const void *zSql,       /* SQL statement, UTF-16 encoded */
3177
  int nByte,              /* Maximum length of zSql in bytes. */
3178
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3179
  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3180
);
3181

    
3182
/*
3183
** CAPI3REF: Retrieving Statement SQL
3184
**
3185
** ^This interface can be used to retrieve a saved copy of the original
3186
** SQL text used to create a [prepared statement] if that statement was
3187
** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3188
*/
3189
SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3190

    
3191
/*
3192
** CAPI3REF: Determine If An SQL Statement Writes The Database
3193
**
3194
** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3195
** and only if the [prepared statement] X makes no direct changes to
3196
** the content of the database file.
3197
**
3198
** Note that [application-defined SQL functions] or
3199
** [virtual tables] might change the database indirectly as a side effect.  
3200
** ^(For example, if an application defines a function "eval()" that 
3201
** calls [sqlite3_exec()], then the following SQL statement would
3202
** change the database file through side-effects:
3203
**
3204
** <blockquote><pre>
3205
**    SELECT eval('DELETE FROM t1') FROM t2;
3206
** </pre></blockquote>
3207
**
3208
** But because the [SELECT] statement does not change the database file
3209
** directly, sqlite3_stmt_readonly() would still return true.)^
3210
**
3211
** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3212
** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3213
** since the statements themselves do not actually modify the database but
3214
** rather they control the timing of when other statements modify the 
3215
** database.  ^The [ATTACH] and [DETACH] statements also cause
3216
** sqlite3_stmt_readonly() to return true since, while those statements
3217
** change the configuration of a database connection, they do not make 
3218
** changes to the content of the database files on disk.
3219
*/
3220
SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3221

    
3222
/*
3223
** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3224
**
3225
** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3226
** [prepared statement] S has been stepped at least once using 
3227
** [sqlite3_step(S)] but has not run to completion and/or has not 
3228
** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)
3229
** interface returns false if S is a NULL pointer.  If S is not a 
3230
** NULL pointer and is not a pointer to a valid [prepared statement]
3231
** object, then the behavior is undefined and probably undesirable.
3232
**
3233
** This interface can be used in combination [sqlite3_next_stmt()]
3234
** to locate all prepared statements associated with a database 
3235
** connection that are in need of being reset.  This can be used,
3236
** for example, in diagnostic routines to search for prepared 
3237
** statements that are holding a transaction open.
3238
*/
3239
SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3240

    
3241
/*
3242
** CAPI3REF: Dynamically Typed Value Object
3243
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3244
**
3245
** SQLite uses the sqlite3_value object to represent all values
3246
** that can be stored in a database table. SQLite uses dynamic typing
3247
** for the values it stores.  ^Values stored in sqlite3_value objects
3248
** can be integers, floating point values, strings, BLOBs, or NULL.
3249
**
3250
** An sqlite3_value object may be either "protected" or "unprotected".
3251
** Some interfaces require a protected sqlite3_value.  Other interfaces
3252
** will accept either a protected or an unprotected sqlite3_value.
3253
** Every interface that accepts sqlite3_value arguments specifies
3254
** whether or not it requires a protected sqlite3_value.
3255
**
3256
** The terms "protected" and "unprotected" refer to whether or not
3257
** a mutex is held.  An internal mutex is held for a protected
3258
** sqlite3_value object but no mutex is held for an unprotected
3259
** sqlite3_value object.  If SQLite is compiled to be single-threaded
3260
** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3261
** or if SQLite is run in one of reduced mutex modes 
3262
** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3263
** then there is no distinction between protected and unprotected
3264
** sqlite3_value objects and they can be used interchangeably.  However,
3265
** for maximum code portability it is recommended that applications
3266
** still make the distinction between protected and unprotected
3267
** sqlite3_value objects even when not strictly required.
3268
**
3269
** ^The sqlite3_value objects that are passed as parameters into the
3270
** implementation of [application-defined SQL functions] are protected.
3271
** ^The sqlite3_value object returned by
3272
** [sqlite3_column_value()] is unprotected.
3273
** Unprotected sqlite3_value objects may only be used with
3274
** [sqlite3_result_value()] and [sqlite3_bind_value()].
3275
** The [sqlite3_value_blob | sqlite3_value_type()] family of
3276
** interfaces require protected sqlite3_value objects.
3277
*/
3278
typedef struct Mem sqlite3_value;
3279

    
3280
/*
3281
** CAPI3REF: SQL Function Context Object
3282
**
3283
** The context in which an SQL function executes is stored in an
3284
** sqlite3_context object.  ^A pointer to an sqlite3_context object
3285
** is always first parameter to [application-defined SQL functions].
3286
** The application-defined SQL function implementation will pass this
3287
** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3288
** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3289
** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3290
** and/or [sqlite3_set_auxdata()].
3291
*/
3292
typedef struct sqlite3_context sqlite3_context;
3293

    
3294
/*
3295
** CAPI3REF: Binding Values To Prepared Statements
3296
** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3297
** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3298
**
3299
** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3300
** literals may be replaced by a [parameter] that matches one of following
3301
** templates:
3302
**
3303
** <ul>
3304
** <li>  ?
3305
** <li>  ?NNN
3306
** <li>  :VVV
3307
** <li>  @VVV
3308
** <li>  $VVV
3309
** </ul>
3310
**
3311
** In the templates above, NNN represents an integer literal,
3312
** and VVV represents an alphanumeric identifier.)^  ^The values of these
3313
** parameters (also called "host parameter names" or "SQL parameters")
3314
** can be set using the sqlite3_bind_*() routines defined here.
3315
**
3316
** ^The first argument to the sqlite3_bind_*() routines is always
3317
** a pointer to the [sqlite3_stmt] object returned from
3318
** [sqlite3_prepare_v2()] or its variants.
3319
**
3320
** ^The second argument is the index of the SQL parameter to be set.
3321
** ^The leftmost SQL parameter has an index of 1.  ^When the same named
3322
** SQL parameter is used more than once, second and subsequent
3323
** occurrences have the same index as the first occurrence.
3324
** ^The index for named parameters can be looked up using the
3325
** [sqlite3_bind_parameter_index()] API if desired.  ^The index
3326
** for "?NNN" parameters is the value of NNN.
3327
** ^The NNN value must be between 1 and the [sqlite3_limit()]
3328
** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3329
**
3330
** ^The third argument is the value to bind to the parameter.
3331
** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3332
** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3333
** is ignored and the end result is the same as sqlite3_bind_null().
3334
**
3335
** ^(In those routines that have a fourth argument, its value is the
3336
** number of bytes in the parameter.  To be clear: the value is the
3337
** number of <u>bytes</u> in the value, not the number of characters.)^
3338
** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3339
** is negative, then the length of the string is
3340
** the number of bytes up to the first zero terminator.
3341
** If the fourth parameter to sqlite3_bind_blob() is negative, then
3342
** the behavior is undefined.
3343
** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3344
** or sqlite3_bind_text16() then that parameter must be the byte offset
3345
** where the NUL terminator would occur assuming the string were NUL
3346
** terminated.  If any NUL characters occur at byte offsets less than 
3347
** the value of the fourth parameter then the resulting string value will
3348
** contain embedded NULs.  The result of expressions involving strings
3349
** with embedded NULs is undefined.
3350
**
3351
** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
3352
** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
3353
** string after SQLite has finished with it.  ^The destructor is called
3354
** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
3355
** sqlite3_bind_text(), or sqlite3_bind_text16() fails.  
3356
** ^If the fifth argument is
3357
** the special value [SQLITE_STATIC], then SQLite assumes that the
3358
** information is in static, unmanaged space and does not need to be freed.
3359
** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3360
** SQLite makes its own private copy of the data immediately, before
3361
** the sqlite3_bind_*() routine returns.
3362
**
3363
** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3364
** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
3365
** (just an integer to hold its size) while it is being processed.
3366
** Zeroblobs are intended to serve as placeholders for BLOBs whose
3367
** content is later written using
3368
** [sqlite3_blob_open | incremental BLOB I/O] routines.
3369
** ^A negative value for the zeroblob results in a zero-length BLOB.
3370
**
3371
** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3372
** for the [prepared statement] or with a prepared statement for which
3373
** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3374
** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
3375
** routine is passed a [prepared statement] that has been finalized, the
3376
** result is undefined and probably harmful.
3377
**
3378
** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3379
** ^Unbound parameters are interpreted as NULL.
3380
**
3381
** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3382
** [error code] if anything goes wrong.
3383
** ^[SQLITE_RANGE] is returned if the parameter
3384
** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
3385
**
3386
** See also: [sqlite3_bind_parameter_count()],
3387
** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3388
*/
3389
SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3390
SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3391
SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3392
SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3393
SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
3394
SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
3395
SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3396
SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3397
SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3398

    
3399
/*
3400
** CAPI3REF: Number Of SQL Parameters
3401
**
3402
** ^This routine can be used to find the number of [SQL parameters]
3403
** in a [prepared statement].  SQL parameters are tokens of the
3404
** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3405
** placeholders for values that are [sqlite3_bind_blob | bound]
3406
** to the parameters at a later time.
3407
**
3408
** ^(This routine actually returns the index of the largest (rightmost)
3409
** parameter. For all forms except ?NNN, this will correspond to the
3410
** number of unique parameters.  If parameters of the ?NNN form are used,
3411
** there may be gaps in the list.)^
3412
**
3413
** See also: [sqlite3_bind_blob|sqlite3_bind()],
3414
** [sqlite3_bind_parameter_name()], and
3415
** [sqlite3_bind_parameter_index()].
3416
*/
3417
SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
3418

    
3419
/*
3420
** CAPI3REF: Name Of A Host Parameter
3421
**
3422
** ^The sqlite3_bind_parameter_name(P,N) interface returns
3423
** the name of the N-th [SQL parameter] in the [prepared statement] P.
3424
** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3425
** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3426
** respectively.
3427
** In other words, the initial ":" or "$" or "@" or "?"
3428
** is included as part of the name.)^
3429
** ^Parameters of the form "?" without a following integer have no name
3430
** and are referred to as "nameless" or "anonymous parameters".
3431
**
3432
** ^The first host parameter has an index of 1, not 0.
3433
**
3434
** ^If the value N is out of range or if the N-th parameter is
3435
** nameless, then NULL is returned.  ^The returned string is
3436
** always in UTF-8 encoding even if the named parameter was
3437
** originally specified as UTF-16 in [sqlite3_prepare16()] or
3438
** [sqlite3_prepare16_v2()].
3439
**
3440
** See also: [sqlite3_bind_blob|sqlite3_bind()],
3441
** [sqlite3_bind_parameter_count()], and
3442
** [sqlite3_bind_parameter_index()].
3443
*/
3444
SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3445

    
3446
/*
3447
** CAPI3REF: Index Of A Parameter With A Given Name
3448
**
3449
** ^Return the index of an SQL parameter given its name.  ^The
3450
** index value returned is suitable for use as the second
3451
** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
3452
** is returned if no matching parameter is found.  ^The parameter
3453
** name must be given in UTF-8 even if the original statement
3454
** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3455
**
3456
** See also: [sqlite3_bind_blob|sqlite3_bind()],
3457
** [sqlite3_bind_parameter_count()], and
3458
** [sqlite3_bind_parameter_index()].
3459
*/
3460
SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3461

    
3462
/*
3463
** CAPI3REF: Reset All Bindings On A Prepared Statement
3464
**
3465
** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3466
** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3467
** ^Use this routine to reset all host parameters to NULL.
3468
*/
3469
SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
3470

    
3471
/*
3472
** CAPI3REF: Number Of Columns In A Result Set
3473
**
3474
** ^Return the number of columns in the result set returned by the
3475
** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3476
** statement that does not return data (for example an [UPDATE]).
3477
**
3478
** See also: [sqlite3_data_count()]
3479
*/
3480
SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
3481

    
3482
/*
3483
** CAPI3REF: Column Names In A Result Set
3484
**
3485
** ^These routines return the name assigned to a particular column
3486
** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
3487
** interface returns a pointer to a zero-terminated UTF-8 string
3488
** and sqlite3_column_name16() returns a pointer to a zero-terminated
3489
** UTF-16 string.  ^The first parameter is the [prepared statement]
3490
** that implements the [SELECT] statement. ^The second parameter is the
3491
** column number.  ^The leftmost column is number 0.
3492
**
3493
** ^The returned string pointer is valid until either the [prepared statement]
3494
** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3495
** reprepared by the first call to [sqlite3_step()] for a particular run
3496
** or until the next call to
3497
** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3498
**
3499
** ^If sqlite3_malloc() fails during the processing of either routine
3500
** (for example during a conversion from UTF-8 to UTF-16) then a
3501
** NULL pointer is returned.
3502
**
3503
** ^The name of a result column is the value of the "AS" clause for
3504
** that column, if there is an AS clause.  If there is no AS clause
3505
** then the name of the column is unspecified and may change from
3506
** one release of SQLite to the next.
3507
*/
3508
SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
3509
SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3510

    
3511
/*
3512
** CAPI3REF: Source Of Data In A Query Result
3513
**
3514
** ^These routines provide a means to determine the database, table, and
3515
** table column that is the origin of a particular result column in
3516
** [SELECT] statement.
3517
** ^The name of the database or table or column can be returned as
3518
** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
3519
** the database name, the _table_ routines return the table name, and
3520
** the origin_ routines return the column name.
3521
** ^The returned string is valid until the [prepared statement] is destroyed
3522
** using [sqlite3_finalize()] or until the statement is automatically
3523
** reprepared by the first call to [sqlite3_step()] for a particular run
3524
** or until the same information is requested
3525
** again in a different encoding.
3526
**
3527
** ^The names returned are the original un-aliased names of the
3528
** database, table, and column.
3529
**
3530
** ^The first argument to these interfaces is a [prepared statement].
3531
** ^These functions return information about the Nth result column returned by
3532
** the statement, where N is the second function argument.
3533
** ^The left-most column is column 0 for these routines.
3534
**
3535
** ^If the Nth column returned by the statement is an expression or
3536
** subquery and is not a column value, then all of these functions return
3537
** NULL.  ^These routine might also return NULL if a memory allocation error
3538
** occurs.  ^Otherwise, they return the name of the attached database, table,
3539
** or column that query result column was extracted from.
3540
**
3541
** ^As with all other SQLite APIs, those whose names end with "16" return
3542
** UTF-16 encoded strings and the other functions return UTF-8.
3543
**
3544
** ^These APIs are only available if the library was compiled with the
3545
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3546
**
3547
** If two or more threads call one or more of these routines against the same
3548
** prepared statement and column at the same time then the results are
3549
** undefined.
3550
**
3551
** If two or more threads call one or more
3552
** [sqlite3_column_database_name | column metadata interfaces]
3553
** for the same [prepared statement] and result column
3554
** at the same time then the results are undefined.
3555
*/
3556
SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
3557
SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
3558
SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
3559
SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
3560
SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
3561
SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
3562

    
3563
/*
3564
** CAPI3REF: Declared Datatype Of A Query Result
3565
**
3566
** ^(The first parameter is a [prepared statement].
3567
** If this statement is a [SELECT] statement and the Nth column of the
3568
** returned result set of that [SELECT] is a table column (not an
3569
** expression or subquery) then the declared type of the table
3570
** column is returned.)^  ^If the Nth column of the result set is an
3571
** expression or subquery, then a NULL pointer is returned.
3572
** ^The returned string is always UTF-8 encoded.
3573
**
3574
** ^(For example, given the database schema:
3575
**
3576
** CREATE TABLE t1(c1 VARIANT);
3577
**
3578
** and the following statement to be compiled:
3579
**
3580
** SELECT c1 + 1, c1 FROM t1;
3581
**
3582
** this routine would return the string "VARIANT" for the second result
3583
** column (i==1), and a NULL pointer for the first result column (i==0).)^
3584
**
3585
** ^SQLite uses dynamic run-time typing.  ^So just because a column
3586
** is declared to contain a particular type does not mean that the
3587
** data stored in that column is of the declared type.  SQLite is
3588
** strongly typed, but the typing is dynamic not static.  ^Type
3589
** is associated with individual values, not with the containers
3590
** used to hold those values.
3591
*/
3592
SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
3593
SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
3594

    
3595
/*
3596
** CAPI3REF: Evaluate An SQL Statement
3597
**
3598
** After a [prepared statement] has been prepared using either
3599
** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3600
** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3601
** must be called one or more times to evaluate the statement.
3602
**
3603
** The details of the behavior of the sqlite3_step() interface depend
3604
** on whether the statement was prepared using the newer "v2" interface
3605
** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3606
** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
3607
** new "v2" interface is recommended for new applications but the legacy
3608
** interface will continue to be supported.
3609
**
3610
** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
3611
** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
3612
** ^With the "v2" interface, any of the other [result codes] or
3613
** [extended result codes] might be returned as well.
3614
**
3615
** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
3616
** database locks it needs to do its job.  ^If the statement is a [COMMIT]
3617
** or occurs outside of an explicit transaction, then you can retry the
3618
** statement.  If the statement is not a [COMMIT] and occurs within an
3619
** explicit transaction then you should rollback the transaction before
3620
** continuing.
3621
**
3622
** ^[SQLITE_DONE] means that the statement has finished executing
3623
** successfully.  sqlite3_step() should not be called again on this virtual
3624
** machine without first calling [sqlite3_reset()] to reset the virtual
3625
** machine back to its initial state.
3626
**
3627
** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
3628
** is returned each time a new row of data is ready for processing by the
3629
** caller. The values may be accessed using the [column access functions].
3630
** sqlite3_step() is called again to retrieve the next row of data.
3631
**
3632
** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
3633
** violation) has occurred.  sqlite3_step() should not be called again on
3634
** the VM. More information may be found by calling [sqlite3_errmsg()].
3635
** ^With the legacy interface, a more specific error code (for example,
3636
** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
3637
** can be obtained by calling [sqlite3_reset()] on the
3638
** [prepared statement].  ^In the "v2" interface,
3639
** the more specific error code is returned directly by sqlite3_step().
3640
**
3641
** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3642
** Perhaps it was called on a [prepared statement] that has
3643
** already been [sqlite3_finalize | finalized] or on one that had
3644
** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
3645
** be the case that the same database connection is being used by two or
3646
** more threads at the same moment in time.
3647
**
3648
** For all versions of SQLite up to and including 3.6.23.1, a call to
3649
** [sqlite3_reset()] was required after sqlite3_step() returned anything
3650
** other than [SQLITE_ROW] before any subsequent invocation of
3651
** sqlite3_step().  Failure to reset the prepared statement using 
3652
** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
3653
** sqlite3_step().  But after version 3.6.23.1, sqlite3_step() began
3654
** calling [sqlite3_reset()] automatically in this circumstance rather
3655
** than returning [SQLITE_MISUSE].  This is not considered a compatibility
3656
** break because any application that ever receives an SQLITE_MISUSE error
3657
** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
3658
** can be used to restore the legacy behavior.
3659
**
3660
** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3661
** API always returns a generic error code, [SQLITE_ERROR], following any
3662
** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
3663
** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3664
** specific [error codes] that better describes the error.
3665
** We admit that this is a goofy design.  The problem has been fixed
3666
** with the "v2" interface.  If you prepare all of your SQL statements
3667
** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3668
** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3669
** then the more specific [error codes] are returned directly
3670
** by sqlite3_step().  The use of the "v2" interface is recommended.
3671
*/
3672
SQLITE_API int sqlite3_step(sqlite3_stmt*);
3673

    
3674
/*
3675
** CAPI3REF: Number of columns in a result set
3676
**
3677
** ^The sqlite3_data_count(P) interface returns the number of columns in the
3678
** current row of the result set of [prepared statement] P.
3679
** ^If prepared statement P does not have results ready to return
3680
** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
3681
** interfaces) then sqlite3_data_count(P) returns 0.
3682
** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
3683
** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
3684
** [sqlite3_step](P) returned [SQLITE_DONE].  ^The sqlite3_data_count(P)
3685
** will return non-zero if previous call to [sqlite3_step](P) returned
3686
** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
3687
** where it always returns zero since each step of that multi-step
3688
** pragma returns 0 columns of data.
3689
**
3690
** See also: [sqlite3_column_count()]
3691
*/
3692
SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
3693

    
3694
/*
3695
** CAPI3REF: Fundamental Datatypes
3696
** KEYWORDS: SQLITE_TEXT
3697
**
3698
** ^(Every value in SQLite has one of five fundamental datatypes:
3699
**
3700
** <ul>
3701
** <li> 64-bit signed integer
3702
** <li> 64-bit IEEE floating point number
3703
** <li> string
3704
** <li> BLOB
3705
** <li> NULL
3706
** </ul>)^
3707
**
3708
** These constants are codes for each of those types.
3709
**
3710
** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3711
** for a completely different meaning.  Software that links against both
3712
** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3713
** SQLITE_TEXT.
3714
*/
3715
#define SQLITE_INTEGER  1
3716
#define SQLITE_FLOAT    2
3717
#define SQLITE_BLOB     4
3718
#define SQLITE_NULL     5
3719
#ifdef SQLITE_TEXT
3720
# undef SQLITE_TEXT
3721
#else
3722
# define SQLITE_TEXT     3
3723
#endif
3724
#define SQLITE3_TEXT     3
3725

    
3726
/*
3727
** CAPI3REF: Result Values From A Query
3728
** KEYWORDS: {column access functions}
3729
**
3730
** These routines form the "result set" interface.
3731
**
3732
** ^These routines return information about a single column of the current
3733
** result row of a query.  ^In every case the first argument is a pointer
3734
** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3735
** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3736
** and the second argument is the index of the column for which information
3737
** should be returned. ^The leftmost column of the result set has the index 0.
3738
** ^The number of columns in the result can be determined using
3739
** [sqlite3_column_count()].
3740
**
3741
** If the SQL statement does not currently point to a valid row, or if the
3742
** column index is out of range, the result is undefined.
3743
** These routines may only be called when the most recent call to
3744
** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3745
** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3746
** If any of these routines are called after [sqlite3_reset()] or
3747
** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3748
** something other than [SQLITE_ROW], the results are undefined.
3749
** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
3750
** are called from a different thread while any of these routines
3751
** are pending, then the results are undefined.
3752
**
3753
** ^The sqlite3_column_type() routine returns the
3754
** [SQLITE_INTEGER | datatype code] for the initial data type
3755
** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
3756
** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
3757
** returned by sqlite3_column_type() is only meaningful if no type
3758
** conversions have occurred as described below.  After a type conversion,
3759
** the value returned by sqlite3_column_type() is undefined.  Future
3760
** versions of SQLite may change the behavior of sqlite3_column_type()
3761
** following a type conversion.
3762
**
3763
** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
3764
** routine returns the number of bytes in that BLOB or string.
3765
** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
3766
** the string to UTF-8 and then returns the number of bytes.
3767
** ^If the result is a numeric value then sqlite3_column_bytes() uses
3768
** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
3769
** the number of bytes in that string.
3770
** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
3771
**
3772
** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
3773
** routine returns the number of bytes in that BLOB or string.
3774
** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
3775
** the string to UTF-16 and then returns the number of bytes.
3776
** ^If the result is a numeric value then sqlite3_column_bytes16() uses
3777
** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
3778
** the number of bytes in that string.
3779
** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
3780
**
3781
** ^The values returned by [sqlite3_column_bytes()] and 
3782
** [sqlite3_column_bytes16()] do not include the zero terminators at the end
3783
** of the string.  ^For clarity: the values returned by
3784
** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
3785
** bytes in the string, not the number of characters.
3786
**
3787
** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
3788
** even empty strings, are always zero-terminated.  ^The return
3789
** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
3790
**
3791
** ^The object returned by [sqlite3_column_value()] is an
3792
** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
3793
** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
3794
** If the [unprotected sqlite3_value] object returned by
3795
** [sqlite3_column_value()] is used in any other way, including calls
3796
** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
3797
** or [sqlite3_value_bytes()], then the behavior is undefined.
3798
**
3799
** These routines attempt to convert the value where appropriate.  ^For
3800
** example, if the internal representation is FLOAT and a text result
3801
** is requested, [sqlite3_snprintf()] is used internally to perform the
3802
** conversion automatically.  ^(The following table details the conversions
3803
** that are applied:
3804
**
3805
** <blockquote>
3806
** <table border="1">
3807
** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
3808
**
3809
** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
3810
** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
3811
** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer
3812
** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer
3813
** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
3814
** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
3815
** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
3816
** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER
3817
** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
3818
** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB
3819
** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER
3820
** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL
3821
** <tr><td>  TEXT    <td>   BLOB    <td> No change
3822
** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER
3823
** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL
3824
** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
3825
** </table>
3826
** </blockquote>)^
3827
**
3828
** The table above makes reference to standard C library functions atoi()
3829
** and atof().  SQLite does not really use these functions.  It has its
3830
** own equivalent internal routines.  The atoi() and atof() names are
3831
** used in the table for brevity and because they are familiar to most
3832
** C programmers.
3833
**
3834
** Note that when type conversions occur, pointers returned by prior
3835
** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
3836
** sqlite3_column_text16() may be invalidated.
3837
** Type conversions and pointer invalidations might occur
3838
** in the following cases:
3839
**
3840
** <ul>
3841
** <li> The initial content is a BLOB and sqlite3_column_text() or
3842
**      sqlite3_column_text16() is called.  A zero-terminator might
3843
**      need to be added to the string.</li>
3844
** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
3845
**      sqlite3_column_text16() is called.  The content must be converted
3846
**      to UTF-16.</li>
3847
** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
3848
**      sqlite3_column_text() is called.  The content must be converted
3849
**      to UTF-8.</li>
3850
** </ul>
3851
**
3852
** ^Conversions between UTF-16be and UTF-16le are always done in place and do
3853
** not invalidate a prior pointer, though of course the content of the buffer
3854
** that the prior pointer references will have been modified.  Other kinds
3855
** of conversion are done in place when it is possible, but sometimes they
3856
** are not possible and in those cases prior pointers are invalidated.
3857
**
3858
** The safest and easiest to remember policy is to invoke these routines
3859
** in one of the following ways:
3860
**
3861
** <ul>
3862
**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
3863
**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
3864
**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
3865
** </ul>
3866
**
3867
** In other words, you should call sqlite3_column_text(),
3868
** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
3869
** into the desired format, then invoke sqlite3_column_bytes() or
3870
** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
3871
** to sqlite3_column_text() or sqlite3_column_blob() with calls to
3872
** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
3873
** with calls to sqlite3_column_bytes().
3874
**
3875
** ^The pointers returned are valid until a type conversion occurs as
3876
** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
3877
** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
3878
** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
3879
** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
3880
** [sqlite3_free()].
3881
**
3882
** ^(If a memory allocation error occurs during the evaluation of any
3883
** of these routines, a default value is returned.  The default value
3884
** is either the integer 0, the floating point number 0.0, or a NULL
3885
** pointer.  Subsequent calls to [sqlite3_errcode()] will return
3886
** [SQLITE_NOMEM].)^
3887
*/
3888
SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
3889
SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
3890
SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
3891
SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
3892
SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
3893
SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
3894
SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
3895
SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
3896
SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
3897
SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
3898

    
3899
/*
3900
** CAPI3REF: Destroy A Prepared Statement Object
3901
**
3902
** ^The sqlite3_finalize() function is called to delete a [prepared statement].
3903
** ^If the most recent evaluation of the statement encountered no errors
3904
** or if the statement is never been evaluated, then sqlite3_finalize() returns
3905
** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
3906
** sqlite3_finalize(S) returns the appropriate [error code] or
3907
** [extended error code].
3908
**
3909
** ^The sqlite3_finalize(S) routine can be called at any point during
3910
** the life cycle of [prepared statement] S:
3911
** before statement S is ever evaluated, after
3912
** one or more calls to [sqlite3_reset()], or after any call
3913
** to [sqlite3_step()] regardless of whether or not the statement has
3914
** completed execution.
3915
**
3916
** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
3917
**
3918
** The application must finalize every [prepared statement] in order to avoid
3919
** resource leaks.  It is a grievous error for the application to try to use
3920
** a prepared statement after it has been finalized.  Any use of a prepared
3921
** statement after it has been finalized can result in undefined and
3922
** undesirable behavior such as segfaults and heap corruption.
3923
*/
3924
SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
3925

    
3926
/*
3927
** CAPI3REF: Reset A Prepared Statement Object
3928
**
3929
** The sqlite3_reset() function is called to reset a [prepared statement]
3930
** object back to its initial state, ready to be re-executed.
3931
** ^Any SQL statement variables that had values bound to them using
3932
** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
3933
** Use [sqlite3_clear_bindings()] to reset the bindings.
3934
**
3935
** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
3936
** back to the beginning of its program.
3937
**
3938
** ^If the most recent call to [sqlite3_step(S)] for the
3939
** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
3940
** or if [sqlite3_step(S)] has never before been called on S,
3941
** then [sqlite3_reset(S)] returns [SQLITE_OK].
3942
**
3943
** ^If the most recent call to [sqlite3_step(S)] for the
3944
** [prepared statement] S indicated an error, then
3945
** [sqlite3_reset(S)] returns an appropriate [error code].
3946
**
3947
** ^The [sqlite3_reset(S)] interface does not change the values
3948
** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
3949
*/
3950
SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
3951

    
3952
/*
3953
** CAPI3REF: Create Or Redefine SQL Functions
3954
** KEYWORDS: {function creation routines}
3955
** KEYWORDS: {application-defined SQL function}
3956
** KEYWORDS: {application-defined SQL functions}
3957
**
3958
** ^These functions (collectively known as "function creation routines")
3959
** are used to add SQL functions or aggregates or to redefine the behavior
3960
** of existing SQL functions or aggregates.  The only differences between
3961
** these routines are the text encoding expected for
3962
** the second parameter (the name of the function being created)
3963
** and the presence or absence of a destructor callback for
3964
** the application data pointer.
3965
**
3966
** ^The first parameter is the [database connection] to which the SQL
3967
** function is to be added.  ^If an application uses more than one database
3968
** connection then application-defined SQL functions must be added
3969
** to each database connection separately.
3970
**
3971
** ^The second parameter is the name of the SQL function to be created or
3972
** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
3973
** representation, exclusive of the zero-terminator.  ^Note that the name
3974
** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.  
3975
** ^Any attempt to create a function with a longer name
3976
** will result in [SQLITE_MISUSE] being returned.
3977
**
3978
** ^The third parameter (nArg)
3979
** is the number of arguments that the SQL function or
3980
** aggregate takes. ^If this parameter is -1, then the SQL function or
3981
** aggregate may take any number of arguments between 0 and the limit
3982
** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
3983
** parameter is less than -1 or greater than 127 then the behavior is
3984
** undefined.
3985
**
3986
** ^The fourth parameter, eTextRep, specifies what
3987
** [SQLITE_UTF8 | text encoding] this SQL function prefers for
3988
** its parameters.  The application should set this parameter to
3989
** [SQLITE_UTF16LE] if the function implementation invokes 
3990
** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
3991
** implementation invokes [sqlite3_value_text16be()] on an input, or
3992
** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
3993
** otherwise.  ^The same SQL function may be registered multiple times using
3994
** different preferred text encodings, with different implementations for
3995
** each encoding.
3996
** ^When multiple implementations of the same function are available, SQLite
3997
** will pick the one that involves the least amount of data conversion.
3998
**
3999
** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4000
** to signal that the function will always return the same result given
4001
** the same inputs within a single SQL statement.  Most SQL functions are
4002
** deterministic.  The built-in [random()] SQL function is an example of a
4003
** function that is not deterministic.  The SQLite query planner is able to
4004
** perform additional optimizations on deterministic functions, so use
4005
** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4006
**
4007
** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
4008
** function can gain access to this pointer using [sqlite3_user_data()].)^
4009
**
4010
** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
4011
** pointers to C-language functions that implement the SQL function or
4012
** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4013
** callback only; NULL pointers must be passed as the xStep and xFinal
4014
** parameters. ^An aggregate SQL function requires an implementation of xStep
4015
** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4016
** SQL function or aggregate, pass NULL pointers for all three function
4017
** callbacks.
4018
**
4019
** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
4020
** then it is destructor for the application data pointer. 
4021
** The destructor is invoked when the function is deleted, either by being
4022
** overloaded or when the database connection closes.)^
4023
** ^The destructor is also invoked if the call to
4024
** sqlite3_create_function_v2() fails.
4025
** ^When the destructor callback of the tenth parameter is invoked, it
4026
** is passed a single argument which is a copy of the application data 
4027
** pointer which was the fifth parameter to sqlite3_create_function_v2().
4028
**
4029
** ^It is permitted to register multiple implementations of the same
4030
** functions with the same name but with either differing numbers of
4031
** arguments or differing preferred text encodings.  ^SQLite will use
4032
** the implementation that most closely matches the way in which the
4033
** SQL function is used.  ^A function implementation with a non-negative
4034
** nArg parameter is a better match than a function implementation with
4035
** a negative nArg.  ^A function where the preferred text encoding
4036
** matches the database encoding is a better
4037
** match than a function where the encoding is different.  
4038
** ^A function where the encoding difference is between UTF16le and UTF16be
4039
** is a closer match than a function where the encoding difference is
4040
** between UTF8 and UTF16.
4041
**
4042
** ^Built-in functions may be overloaded by new application-defined functions.
4043
**
4044
** ^An application-defined function is permitted to call other
4045
** SQLite interfaces.  However, such calls must not
4046
** close the database connection nor finalize or reset the prepared
4047
** statement in which the function is running.
4048
*/
4049
SQLITE_API int sqlite3_create_function(
4050
  sqlite3 *db,
4051
  const char *zFunctionName,
4052
  int nArg,
4053
  int eTextRep,
4054
  void *pApp,
4055
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4056
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4057
  void (*xFinal)(sqlite3_context*)
4058
);
4059
SQLITE_API int sqlite3_create_function16(
4060
  sqlite3 *db,
4061
  const void *zFunctionName,
4062
  int nArg,
4063
  int eTextRep,
4064
  void *pApp,
4065
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4066
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4067
  void (*xFinal)(sqlite3_context*)
4068
);
4069
SQLITE_API int sqlite3_create_function_v2(
4070
  sqlite3 *db,
4071
  const char *zFunctionName,
4072
  int nArg,
4073
  int eTextRep,
4074
  void *pApp,
4075
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4076
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4077
  void (*xFinal)(sqlite3_context*),
4078
  void(*xDestroy)(void*)
4079
);
4080

    
4081
/*
4082
** CAPI3REF: Text Encodings
4083
**
4084
** These constant define integer codes that represent the various
4085
** text encodings supported by SQLite.
4086
*/
4087
#define SQLITE_UTF8           1
4088
#define SQLITE_UTF16LE        2
4089
#define SQLITE_UTF16BE        3
4090
#define SQLITE_UTF16          4    /* Use native byte order */
4091
#define SQLITE_ANY            5    /* Deprecated */
4092
#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
4093

    
4094
/*
4095
** CAPI3REF: Function Flags
4096
**
4097
** These constants may be ORed together with the 
4098
** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4099
** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4100
** [sqlite3_create_function_v2()].
4101
*/
4102
#define SQLITE_DETERMINISTIC    0x800
4103

    
4104
/*
4105
** CAPI3REF: Deprecated Functions
4106
** DEPRECATED
4107
**
4108
** These functions are [deprecated].  In order to maintain
4109
** backwards compatibility with older code, these functions continue 
4110
** to be supported.  However, new applications should avoid
4111
** the use of these functions.  To help encourage people to avoid
4112
** using these functions, we are not going to tell you what they do.
4113
*/
4114
#ifndef SQLITE_OMIT_DEPRECATED
4115
SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4116
SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4117
SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4118
SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4119
SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4120
SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4121
                      void*,sqlite3_int64);
4122
#endif
4123

    
4124
/*
4125
** CAPI3REF: Obtaining SQL Function Parameter Values
4126
**
4127
** The C-language implementation of SQL functions and aggregates uses
4128
** this set of interface routines to access the parameter values on
4129
** the function or aggregate.
4130
**
4131
** The xFunc (for scalar functions) or xStep (for aggregates) parameters
4132
** to [sqlite3_create_function()] and [sqlite3_create_function16()]
4133
** define callbacks that implement the SQL functions and aggregates.
4134
** The 3rd parameter to these callbacks is an array of pointers to
4135
** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
4136
** each parameter to the SQL function.  These routines are used to
4137
** extract values from the [sqlite3_value] objects.
4138
**
4139
** These routines work only with [protected sqlite3_value] objects.
4140
** Any attempt to use these routines on an [unprotected sqlite3_value]
4141
** object results in undefined behavior.
4142
**
4143
** ^These routines work just like the corresponding [column access functions]
4144
** except that  these routines take a single [protected sqlite3_value] object
4145
** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4146
**
4147
** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4148
** in the native byte-order of the host machine.  ^The
4149
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4150
** extract UTF-16 strings as big-endian and little-endian respectively.
4151
**
4152
** ^(The sqlite3_value_numeric_type() interface attempts to apply
4153
** numeric affinity to the value.  This means that an attempt is
4154
** made to convert the value to an integer or floating point.  If
4155
** such a conversion is possible without loss of information (in other
4156
** words, if the value is a string that looks like a number)
4157
** then the conversion is performed.  Otherwise no conversion occurs.
4158
** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4159
**
4160
** Please pay particular attention to the fact that the pointer returned
4161
** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4162
** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4163
** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4164
** or [sqlite3_value_text16()].
4165
**
4166
** These routines must be called from the same thread as
4167
** the SQL function that supplied the [sqlite3_value*] parameters.
4168
*/
4169
SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
4170
SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
4171
SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
4172
SQLITE_API double sqlite3_value_double(sqlite3_value*);
4173
SQLITE_API int sqlite3_value_int(sqlite3_value*);
4174
SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4175
SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4176
SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
4177
SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
4178
SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
4179
SQLITE_API int sqlite3_value_type(sqlite3_value*);
4180
SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
4181

    
4182
/*
4183
** CAPI3REF: Obtain Aggregate Function Context
4184
**
4185
** Implementations of aggregate SQL functions use this
4186
** routine to allocate memory for storing their state.
4187
**
4188
** ^The first time the sqlite3_aggregate_context(C,N) routine is called 
4189
** for a particular aggregate function, SQLite
4190
** allocates N of memory, zeroes out that memory, and returns a pointer
4191
** to the new memory. ^On second and subsequent calls to
4192
** sqlite3_aggregate_context() for the same aggregate function instance,
4193
** the same buffer is returned.  Sqlite3_aggregate_context() is normally
4194
** called once for each invocation of the xStep callback and then one
4195
** last time when the xFinal callback is invoked.  ^(When no rows match
4196
** an aggregate query, the xStep() callback of the aggregate function
4197
** implementation is never called and xFinal() is called exactly once.
4198
** In those cases, sqlite3_aggregate_context() might be called for the
4199
** first time from within xFinal().)^
4200
**
4201
** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 
4202
** when first called if N is less than or equal to zero or if a memory
4203
** allocate error occurs.
4204
**
4205
** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4206
** determined by the N parameter on first successful call.  Changing the
4207
** value of N in subsequent call to sqlite3_aggregate_context() within
4208
** the same aggregate function instance will not resize the memory
4209
** allocation.)^  Within the xFinal callback, it is customary to set
4210
** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 
4211
** pointless memory allocations occur.
4212
**
4213
** ^SQLite automatically frees the memory allocated by 
4214
** sqlite3_aggregate_context() when the aggregate query concludes.
4215
**
4216
** The first parameter must be a copy of the
4217
** [sqlite3_context | SQL function context] that is the first parameter
4218
** to the xStep or xFinal callback routine that implements the aggregate
4219
** function.
4220
**
4221
** This routine must be called from the same thread in which
4222
** the aggregate SQL function is running.
4223
*/
4224
SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4225

    
4226
/*
4227
** CAPI3REF: User Data For Functions
4228
**
4229
** ^The sqlite3_user_data() interface returns a copy of
4230
** the pointer that was the pUserData parameter (the 5th parameter)
4231
** of the [sqlite3_create_function()]
4232
** and [sqlite3_create_function16()] routines that originally
4233
** registered the application defined function.
4234
**
4235
** This routine must be called from the same thread in which
4236
** the application-defined function is running.
4237
*/
4238
SQLITE_API void *sqlite3_user_data(sqlite3_context*);
4239

    
4240
/*
4241
** CAPI3REF: Database Connection For Functions
4242
**
4243
** ^The sqlite3_context_db_handle() interface returns a copy of
4244
** the pointer to the [database connection] (the 1st parameter)
4245
** of the [sqlite3_create_function()]
4246
** and [sqlite3_create_function16()] routines that originally
4247
** registered the application defined function.
4248
*/
4249
SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
4250

    
4251
/*
4252
** CAPI3REF: Function Auxiliary Data
4253
**
4254
** These functions may be used by (non-aggregate) SQL functions to
4255
** associate metadata with argument values. If the same value is passed to
4256
** multiple invocations of the same SQL function during query execution, under
4257
** some circumstances the associated metadata may be preserved.  An example
4258
** of where this might be useful is in a regular-expression matching
4259
** function. The compiled version of the regular expression can be stored as
4260
** metadata associated with the pattern string.  
4261
** Then as long as the pattern string remains the same,
4262
** the compiled regular expression can be reused on multiple
4263
** invocations of the same function.
4264
**
4265
** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4266
** associated by the sqlite3_set_auxdata() function with the Nth argument
4267
** value to the application-defined function. ^If there is no metadata
4268
** associated with the function argument, this sqlite3_get_auxdata() interface
4269
** returns a NULL pointer.
4270
**
4271
** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
4272
** argument of the application-defined function.  ^Subsequent
4273
** calls to sqlite3_get_auxdata(C,N) return P from the most recent
4274
** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
4275
** NULL if the metadata has been discarded.
4276
** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
4277
** SQLite will invoke the destructor function X with parameter P exactly
4278
** once, when the metadata is discarded.
4279
** SQLite is free to discard the metadata at any time, including: <ul>
4280
** <li> when the corresponding function parameter changes, or
4281
** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
4282
**      SQL statement, or
4283
** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
4284
** <li> during the original sqlite3_set_auxdata() call when a memory 
4285
**      allocation error occurs. </ul>)^
4286
**
4287
** Note the last bullet in particular.  The destructor X in 
4288
** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
4289
** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()
4290
** should be called near the end of the function implementation and the
4291
** function implementation should not make any use of P after
4292
** sqlite3_set_auxdata() has been called.
4293
**
4294
** ^(In practice, metadata is preserved between function calls for
4295
** function parameters that are compile-time constants, including literal
4296
** values and [parameters] and expressions composed from the same.)^
4297
**
4298
** These routines must be called from the same thread in which
4299
** the SQL function is running.
4300
*/
4301
SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
4302
SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4303

    
4304

    
4305
/*
4306
** CAPI3REF: Constants Defining Special Destructor Behavior
4307
**
4308
** These are special values for the destructor that is passed in as the
4309
** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
4310
** argument is SQLITE_STATIC, it means that the content pointer is constant
4311
** and will never change.  It does not need to be destroyed.  ^The
4312
** SQLITE_TRANSIENT value means that the content will likely change in
4313
** the near future and that SQLite should make its own private copy of
4314
** the content before returning.
4315
**
4316
** The typedef is necessary to work around problems in certain
4317
** C++ compilers.
4318
*/
4319
typedef void (*sqlite3_destructor_type)(void*);
4320
#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
4321
#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
4322

    
4323
/*
4324
** CAPI3REF: Setting The Result Of An SQL Function
4325
**
4326
** These routines are used by the xFunc or xFinal callbacks that
4327
** implement SQL functions and aggregates.  See
4328
** [sqlite3_create_function()] and [sqlite3_create_function16()]
4329
** for additional information.
4330
**
4331
** These functions work very much like the [parameter binding] family of
4332
** functions used to bind values to host parameters in prepared statements.
4333
** Refer to the [SQL parameter] documentation for additional information.
4334
**
4335
** ^The sqlite3_result_blob() interface sets the result from
4336
** an application-defined function to be the BLOB whose content is pointed
4337
** to by the second parameter and which is N bytes long where N is the
4338
** third parameter.
4339
**
4340
** ^The sqlite3_result_zeroblob() interfaces set the result of
4341
** the application-defined function to be a BLOB containing all zero
4342
** bytes and N bytes in size, where N is the value of the 2nd parameter.
4343
**
4344
** ^The sqlite3_result_double() interface sets the result from
4345
** an application-defined function to be a floating point value specified
4346
** by its 2nd argument.
4347
**
4348
** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4349
** cause the implemented SQL function to throw an exception.
4350
** ^SQLite uses the string pointed to by the
4351
** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4352
** as the text of an error message.  ^SQLite interprets the error
4353
** message string from sqlite3_result_error() as UTF-8. ^SQLite
4354
** interprets the string from sqlite3_result_error16() as UTF-16 in native
4355
** byte order.  ^If the third parameter to sqlite3_result_error()
4356
** or sqlite3_result_error16() is negative then SQLite takes as the error
4357
** message all text up through the first zero character.
4358
** ^If the third parameter to sqlite3_result_error() or
4359
** sqlite3_result_error16() is non-negative then SQLite takes that many
4360
** bytes (not characters) from the 2nd parameter as the error message.
4361
** ^The sqlite3_result_error() and sqlite3_result_error16()
4362
** routines make a private copy of the error message text before
4363
** they return.  Hence, the calling function can deallocate or
4364
** modify the text after they return without harm.
4365
** ^The sqlite3_result_error_code() function changes the error code
4366
** returned by SQLite as a result of an error in a function.  ^By default,
4367
** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
4368
** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4369
**
4370
** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
4371
** error indicating that a string or BLOB is too long to represent.
4372
**
4373
** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
4374
** error indicating that a memory allocation failed.
4375
**
4376
** ^The sqlite3_result_int() interface sets the return value
4377
** of the application-defined function to be the 32-bit signed integer
4378
** value given in the 2nd argument.
4379
** ^The sqlite3_result_int64() interface sets the return value
4380
** of the application-defined function to be the 64-bit signed integer
4381
** value given in the 2nd argument.
4382
**
4383
** ^The sqlite3_result_null() interface sets the return value
4384
** of the application-defined function to be NULL.
4385
**
4386
** ^The sqlite3_result_text(), sqlite3_result_text16(),
4387
** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4388
** set the return value of the application-defined function to be
4389
** a text string which is represented as UTF-8, UTF-16 native byte order,
4390
** UTF-16 little endian, or UTF-16 big endian, respectively.
4391
** ^SQLite takes the text result from the application from
4392
** the 2nd parameter of the sqlite3_result_text* interfaces.
4393
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4394
** is negative, then SQLite takes result text from the 2nd parameter
4395
** through the first zero character.
4396
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4397
** is non-negative, then as many bytes (not characters) of the text
4398
** pointed to by the 2nd parameter are taken as the application-defined
4399
** function result.  If the 3rd parameter is non-negative, then it
4400
** must be the byte offset into the string where the NUL terminator would
4401
** appear if the string where NUL terminated.  If any NUL characters occur
4402
** in the string at a byte offset that is less than the value of the 3rd
4403
** parameter, then the resulting string will contain embedded NULs and the
4404
** result of expressions operating on strings with embedded NULs is undefined.
4405
** ^If the 4th parameter to the sqlite3_result_text* interfaces
4406
** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4407
** function as the destructor on the text or BLOB result when it has
4408
** finished using that result.
4409
** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4410
** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4411
** assumes that the text or BLOB result is in constant space and does not
4412
** copy the content of the parameter nor call a destructor on the content
4413
** when it has finished using that result.
4414
** ^If the 4th parameter to the sqlite3_result_text* interfaces
4415
** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4416
** then SQLite makes a copy of the result into space obtained from
4417
** from [sqlite3_malloc()] before it returns.
4418
**
4419
** ^The sqlite3_result_value() interface sets the result of
4420
** the application-defined function to be a copy the
4421
** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
4422
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4423
** so that the [sqlite3_value] specified in the parameter may change or
4424
** be deallocated after sqlite3_result_value() returns without harm.
4425
** ^A [protected sqlite3_value] object may always be used where an
4426
** [unprotected sqlite3_value] object is required, so either
4427
** kind of [sqlite3_value] object can be used with this interface.
4428
**
4429
** If these routines are called from within the different thread
4430
** than the one containing the application-defined function that received
4431
** the [sqlite3_context] pointer, the results are undefined.
4432
*/
4433
SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4434
SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
4435
SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
4436
SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
4437
SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
4438
SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
4439
SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
4440
SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
4441
SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4442
SQLITE_API void sqlite3_result_null(sqlite3_context*);
4443
SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4444
SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4445
SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4446
SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4447
SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4448
SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
4449

    
4450
/*
4451
** CAPI3REF: Define New Collating Sequences
4452
**
4453
** ^These functions add, remove, or modify a [collation] associated
4454
** with the [database connection] specified as the first argument.
4455
**
4456
** ^The name of the collation is a UTF-8 string
4457
** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4458
** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4459
** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4460
** considered to be the same name.
4461
**
4462
** ^(The third argument (eTextRep) must be one of the constants:
4463
** <ul>
4464
** <li> [SQLITE_UTF8],
4465
** <li> [SQLITE_UTF16LE],
4466
** <li> [SQLITE_UTF16BE],
4467
** <li> [SQLITE_UTF16], or
4468
** <li> [SQLITE_UTF16_ALIGNED].
4469
** </ul>)^
4470
** ^The eTextRep argument determines the encoding of strings passed
4471
** to the collating function callback, xCallback.
4472
** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4473
** force strings to be UTF16 with native byte order.
4474
** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4475
** on an even byte address.
4476
**
4477
** ^The fourth argument, pArg, is an application data pointer that is passed
4478
** through as the first argument to the collating function callback.
4479
**
4480
** ^The fifth argument, xCallback, is a pointer to the collating function.
4481
** ^Multiple collating functions can be registered using the same name but
4482
** with different eTextRep parameters and SQLite will use whichever
4483
** function requires the least amount of data transformation.
4484
** ^If the xCallback argument is NULL then the collating function is
4485
** deleted.  ^When all collating functions having the same name are deleted,
4486
** that collation is no longer usable.
4487
**
4488
** ^The collating function callback is invoked with a copy of the pArg 
4489
** application data pointer and with two strings in the encoding specified
4490
** by the eTextRep argument.  The collating function must return an
4491
** integer that is negative, zero, or positive
4492
** if the first string is less than, equal to, or greater than the second,
4493
** respectively.  A collating function must always return the same answer
4494
** given the same inputs.  If two or more collating functions are registered
4495
** to the same collation name (using different eTextRep values) then all
4496
** must give an equivalent answer when invoked with equivalent strings.
4497
** The collating function must obey the following properties for all
4498
** strings A, B, and C:
4499
**
4500
** <ol>
4501
** <li> If A==B then B==A.
4502
** <li> If A==B and B==C then A==C.
4503
** <li> If A&lt;B THEN B&gt;A.
4504
** <li> If A&lt;B and B&lt;C then A&lt;C.
4505
** </ol>
4506
**
4507
** If a collating function fails any of the above constraints and that
4508
** collating function is  registered and used, then the behavior of SQLite
4509
** is undefined.
4510
**
4511
** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4512
** with the addition that the xDestroy callback is invoked on pArg when
4513
** the collating function is deleted.
4514
** ^Collating functions are deleted when they are overridden by later
4515
** calls to the collation creation functions or when the
4516
** [database connection] is closed using [sqlite3_close()].
4517
**
4518
** ^The xDestroy callback is <u>not</u> called if the 
4519
** sqlite3_create_collation_v2() function fails.  Applications that invoke
4520
** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 
4521
** check the return code and dispose of the application data pointer
4522
** themselves rather than expecting SQLite to deal with it for them.
4523
** This is different from every other SQLite interface.  The inconsistency 
4524
** is unfortunate but cannot be changed without breaking backwards 
4525
** compatibility.
4526
**
4527
** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4528
*/
4529
SQLITE_API int sqlite3_create_collation(
4530
  sqlite3*, 
4531
  const char *zName, 
4532
  int eTextRep, 
4533
  void *pArg,
4534
  int(*xCompare)(void*,int,const void*,int,const void*)
4535
);
4536
SQLITE_API int sqlite3_create_collation_v2(
4537
  sqlite3*, 
4538
  const char *zName, 
4539
  int eTextRep, 
4540
  void *pArg,
4541
  int(*xCompare)(void*,int,const void*,int,const void*),
4542
  void(*xDestroy)(void*)
4543
);
4544
SQLITE_API int sqlite3_create_collation16(
4545
  sqlite3*, 
4546
  const void *zName,
4547
  int eTextRep, 
4548
  void *pArg,
4549
  int(*xCompare)(void*,int,const void*,int,const void*)
4550
);
4551

    
4552
/*
4553
** CAPI3REF: Collation Needed Callbacks
4554
**
4555
** ^To avoid having to register all collation sequences before a database
4556
** can be used, a single callback function may be registered with the
4557
** [database connection] to be invoked whenever an undefined collation
4558
** sequence is required.
4559
**
4560
** ^If the function is registered using the sqlite3_collation_needed() API,
4561
** then it is passed the names of undefined collation sequences as strings
4562
** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
4563
** the names are passed as UTF-16 in machine native byte order.
4564
** ^A call to either function replaces the existing collation-needed callback.
4565
**
4566
** ^(When the callback is invoked, the first argument passed is a copy
4567
** of the second argument to sqlite3_collation_needed() or
4568
** sqlite3_collation_needed16().  The second argument is the database
4569
** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4570
** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4571
** sequence function required.  The fourth parameter is the name of the
4572
** required collation sequence.)^
4573
**
4574
** The callback function should register the desired collation using
4575
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4576
** [sqlite3_create_collation_v2()].
4577
*/
4578
SQLITE_API int sqlite3_collation_needed(
4579
  sqlite3*, 
4580
  void*, 
4581
  void(*)(void*,sqlite3*,int eTextRep,const char*)
4582
);
4583
SQLITE_API int sqlite3_collation_needed16(
4584
  sqlite3*, 
4585
  void*,
4586
  void(*)(void*,sqlite3*,int eTextRep,const void*)
4587
);
4588

    
4589
#ifdef SQLITE_HAS_CODEC
4590
/*
4591
** Specify the key for an encrypted database.  This routine should be
4592
** called right after sqlite3_open().
4593
**
4594
** The code to implement this API is not available in the public release
4595
** of SQLite.
4596
*/
4597
SQLITE_API int sqlite3_key(
4598
  sqlite3 *db,                   /* Database to be rekeyed */
4599
  const void *pKey, int nKey     /* The key */
4600
);
4601
SQLITE_API int sqlite3_key_v2(
4602
  sqlite3 *db,                   /* Database to be rekeyed */
4603
  const char *zDbName,           /* Name of the database */
4604
  const void *pKey, int nKey     /* The key */
4605
);
4606

    
4607
/*
4608
** Change the key on an open database.  If the current database is not
4609
** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
4610
** database is decrypted.
4611
**
4612
** The code to implement this API is not available in the public release
4613
** of SQLite.
4614
*/
4615
SQLITE_API int sqlite3_rekey(
4616
  sqlite3 *db,                   /* Database to be rekeyed */
4617
  const void *pKey, int nKey     /* The new key */
4618
);
4619
SQLITE_API int sqlite3_rekey_v2(
4620
  sqlite3 *db,                   /* Database to be rekeyed */
4621
  const char *zDbName,           /* Name of the database */
4622
  const void *pKey, int nKey     /* The new key */
4623
);
4624

    
4625
/*
4626
** Specify the activation key for a SEE database.  Unless 
4627
** activated, none of the SEE routines will work.
4628
*/
4629
SQLITE_API void sqlite3_activate_see(
4630
  const char *zPassPhrase        /* Activation phrase */
4631
);
4632
#endif
4633

    
4634
#ifdef SQLITE_ENABLE_CEROD
4635
/*
4636
** Specify the activation key for a CEROD database.  Unless 
4637
** activated, none of the CEROD routines will work.
4638
*/
4639
SQLITE_API void sqlite3_activate_cerod(
4640
  const char *zPassPhrase        /* Activation phrase */
4641
);
4642
#endif
4643

    
4644
/*
4645
** CAPI3REF: Suspend Execution For A Short Time
4646
**
4647
** The sqlite3_sleep() function causes the current thread to suspend execution
4648
** for at least a number of milliseconds specified in its parameter.
4649
**
4650
** If the operating system does not support sleep requests with
4651
** millisecond time resolution, then the time will be rounded up to
4652
** the nearest second. The number of milliseconds of sleep actually
4653
** requested from the operating system is returned.
4654
**
4655
** ^SQLite implements this interface by calling the xSleep()
4656
** method of the default [sqlite3_vfs] object.  If the xSleep() method
4657
** of the default VFS is not implemented correctly, or not implemented at
4658
** all, then the behavior of sqlite3_sleep() may deviate from the description
4659
** in the previous paragraphs.
4660
*/
4661
SQLITE_API int sqlite3_sleep(int);
4662

    
4663
/*
4664
** CAPI3REF: Name Of The Folder Holding Temporary Files
4665
**
4666
** ^(If this global variable is made to point to a string which is
4667
** the name of a folder (a.k.a. directory), then all temporary files
4668
** created by SQLite when using a built-in [sqlite3_vfs | VFS]
4669
** will be placed in that directory.)^  ^If this variable
4670
** is a NULL pointer, then SQLite performs a search for an appropriate
4671
** temporary file directory.
4672
**
4673
** It is not safe to read or modify this variable in more than one
4674
** thread at a time.  It is not safe to read or modify this variable
4675
** if a [database connection] is being used at the same time in a separate
4676
** thread.
4677
** It is intended that this variable be set once
4678
** as part of process initialization and before any SQLite interface
4679
** routines have been called and that this variable remain unchanged
4680
** thereafter.
4681
**
4682
** ^The [temp_store_directory pragma] may modify this variable and cause
4683
** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
4684
** the [temp_store_directory pragma] always assumes that any string
4685
** that this variable points to is held in memory obtained from 
4686
** [sqlite3_malloc] and the pragma may attempt to free that memory
4687
** using [sqlite3_free].
4688
** Hence, if this variable is modified directly, either it should be
4689
** made NULL or made to point to memory obtained from [sqlite3_malloc]
4690
** or else the use of the [temp_store_directory pragma] should be avoided.
4691
**
4692
** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
4693
** prior to calling [sqlite3_open] or [sqlite3_open_v2].  Otherwise, various
4694
** features that require the use of temporary files may fail.  Here is an
4695
** example of how to do this using C++ with the Windows Runtime:
4696
**
4697
** <blockquote><pre>
4698
** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
4699
** &nbsp;     TemporaryFolder->Path->Data();
4700
** char zPathBuf&#91;MAX_PATH + 1&#93;;
4701
** memset(zPathBuf, 0, sizeof(zPathBuf));
4702
** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
4703
** &nbsp;     NULL, NULL);
4704
** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
4705
** </pre></blockquote>
4706
*/
4707
SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
4708

    
4709
/*
4710
** CAPI3REF: Name Of The Folder Holding Database Files
4711
**
4712
** ^(If this global variable is made to point to a string which is
4713
** the name of a folder (a.k.a. directory), then all database files
4714
** specified with a relative pathname and created or accessed by
4715
** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
4716
** to be relative to that directory.)^ ^If this variable is a NULL
4717
** pointer, then SQLite assumes that all database files specified
4718
** with a relative pathname are relative to the current directory
4719
** for the process.  Only the windows VFS makes use of this global
4720
** variable; it is ignored by the unix VFS.
4721
**
4722
** Changing the value of this variable while a database connection is
4723
** open can result in a corrupt database.
4724
**
4725
** It is not safe to read or modify this variable in more than one
4726
** thread at a time.  It is not safe to read or modify this variable
4727
** if a [database connection] is being used at the same time in a separate
4728
** thread.
4729
** It is intended that this variable be set once
4730
** as part of process initialization and before any SQLite interface
4731
** routines have been called and that this variable remain unchanged
4732
** thereafter.
4733
**
4734
** ^The [data_store_directory pragma] may modify this variable and cause
4735
** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
4736
** the [data_store_directory pragma] always assumes that any string
4737
** that this variable points to is held in memory obtained from 
4738
** [sqlite3_malloc] and the pragma may attempt to free that memory
4739
** using [sqlite3_free].
4740
** Hence, if this variable is modified directly, either it should be
4741
** made NULL or made to point to memory obtained from [sqlite3_malloc]
4742
** or else the use of the [data_store_directory pragma] should be avoided.
4743
*/
4744
SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
4745

    
4746
/*
4747
** CAPI3REF: Test For Auto-Commit Mode
4748
** KEYWORDS: {autocommit mode}
4749
**
4750
** ^The sqlite3_get_autocommit() interface returns non-zero or
4751
** zero if the given database connection is or is not in autocommit mode,
4752
** respectively.  ^Autocommit mode is on by default.
4753
** ^Autocommit mode is disabled by a [BEGIN] statement.
4754
** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
4755
**
4756
** If certain kinds of errors occur on a statement within a multi-statement
4757
** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
4758
** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
4759
** transaction might be rolled back automatically.  The only way to
4760
** find out whether SQLite automatically rolled back the transaction after
4761
** an error is to use this function.
4762
**
4763
** If another thread changes the autocommit status of the database
4764
** connection while this routine is running, then the return value
4765
** is undefined.
4766
*/
4767
SQLITE_API int sqlite3_get_autocommit(sqlite3*);
4768

    
4769
/*
4770
** CAPI3REF: Find The Database Handle Of A Prepared Statement
4771
**
4772
** ^The sqlite3_db_handle interface returns the [database connection] handle
4773
** to which a [prepared statement] belongs.  ^The [database connection]
4774
** returned by sqlite3_db_handle is the same [database connection]
4775
** that was the first argument
4776
** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
4777
** create the statement in the first place.
4778
*/
4779
SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
4780

    
4781
/*
4782
** CAPI3REF: Return The Filename For A Database Connection
4783
**
4784
** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
4785
** associated with database N of connection D.  ^The main database file
4786
** has the name "main".  If there is no attached database N on the database
4787
** connection D, or if database N is a temporary or in-memory database, then
4788
** a NULL pointer is returned.
4789
**
4790
** ^The filename returned by this function is the output of the
4791
** xFullPathname method of the [VFS].  ^In other words, the filename
4792
** will be an absolute pathname, even if the filename used
4793
** to open the database originally was a URI or relative pathname.
4794
*/
4795
SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
4796

    
4797
/*
4798
** CAPI3REF: Determine if a database is read-only
4799
**
4800
** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
4801
** of connection D is read-only, 0 if it is read/write, or -1 if N is not
4802
** the name of a database on connection D.
4803
*/
4804
SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
4805

    
4806
/*
4807
** CAPI3REF: Find the next prepared statement
4808
**
4809
** ^This interface returns a pointer to the next [prepared statement] after
4810
** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
4811
** then this interface returns a pointer to the first prepared statement
4812
** associated with the database connection pDb.  ^If no prepared statement
4813
** satisfies the conditions of this routine, it returns NULL.
4814
**
4815
** The [database connection] pointer D in a call to
4816
** [sqlite3_next_stmt(D,S)] must refer to an open database
4817
** connection and in particular must not be a NULL pointer.
4818
*/
4819
SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
4820

    
4821
/*
4822
** CAPI3REF: Commit And Rollback Notification Callbacks
4823
**
4824
** ^The sqlite3_commit_hook() interface registers a callback
4825
** function to be invoked whenever a transaction is [COMMIT | committed].
4826
** ^Any callback set by a previous call to sqlite3_commit_hook()
4827
** for the same database connection is overridden.
4828
** ^The sqlite3_rollback_hook() interface registers a callback
4829
** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
4830
** ^Any callback set by a previous call to sqlite3_rollback_hook()
4831
** for the same database connection is overridden.
4832
** ^The pArg argument is passed through to the callback.
4833
** ^If the callback on a commit hook function returns non-zero,
4834
** then the commit is converted into a rollback.
4835
**
4836
** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
4837
** return the P argument from the previous call of the same function
4838
** on the same [database connection] D, or NULL for
4839
** the first call for each function on D.
4840
**
4841
** The commit and rollback hook callbacks are not reentrant.
4842
** The callback implementation must not do anything that will modify
4843
** the database connection that invoked the callback.  Any actions
4844
** to modify the database connection must be deferred until after the
4845
** completion of the [sqlite3_step()] call that triggered the commit
4846
** or rollback hook in the first place.
4847
** Note that running any other SQL statements, including SELECT statements,
4848
** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
4849
** the database connections for the meaning of "modify" in this paragraph.
4850
**
4851
** ^Registering a NULL function disables the callback.
4852
**
4853
** ^When the commit hook callback routine returns zero, the [COMMIT]
4854
** operation is allowed to continue normally.  ^If the commit hook
4855
** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
4856
** ^The rollback hook is invoked on a rollback that results from a commit
4857
** hook returning non-zero, just as it would be with any other rollback.
4858
**
4859
** ^For the purposes of this API, a transaction is said to have been
4860
** rolled back if an explicit "ROLLBACK" statement is executed, or
4861
** an error or constraint causes an implicit rollback to occur.
4862
** ^The rollback callback is not invoked if a transaction is
4863
** automatically rolled back because the database connection is closed.
4864
**
4865
** See also the [sqlite3_update_hook()] interface.
4866
*/
4867
SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
4868
SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
4869

    
4870
/*
4871
** CAPI3REF: Data Change Notification Callbacks
4872
**
4873
** ^The sqlite3_update_hook() interface registers a callback function
4874
** with the [database connection] identified by the first argument
4875
** to be invoked whenever a row is updated, inserted or deleted in
4876
** a rowid table.
4877
** ^Any callback set by a previous call to this function
4878
** for the same database connection is overridden.
4879
**
4880
** ^The second argument is a pointer to the function to invoke when a
4881
** row is updated, inserted or deleted in a rowid table.
4882
** ^The first argument to the callback is a copy of the third argument
4883
** to sqlite3_update_hook().
4884
** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
4885
** or [SQLITE_UPDATE], depending on the operation that caused the callback
4886
** to be invoked.
4887
** ^The third and fourth arguments to the callback contain pointers to the
4888
** database and table name containing the affected row.
4889
** ^The final callback parameter is the [rowid] of the row.
4890
** ^In the case of an update, this is the [rowid] after the update takes place.
4891
**
4892
** ^(The update hook is not invoked when internal system tables are
4893
** modified (i.e. sqlite_master and sqlite_sequence).)^
4894
** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
4895
**
4896
** ^In the current implementation, the update hook
4897
** is not invoked when duplication rows are deleted because of an
4898
** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
4899
** invoked when rows are deleted using the [truncate optimization].
4900
** The exceptions defined in this paragraph might change in a future
4901
** release of SQLite.
4902
**
4903
** The update hook implementation must not do anything that will modify
4904
** the database connection that invoked the update hook.  Any actions
4905
** to modify the database connection must be deferred until after the
4906
** completion of the [sqlite3_step()] call that triggered the update hook.
4907
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
4908
** database connections for the meaning of "modify" in this paragraph.
4909
**
4910
** ^The sqlite3_update_hook(D,C,P) function
4911
** returns the P argument from the previous call
4912
** on the same [database connection] D, or NULL for
4913
** the first call on D.
4914
**
4915
** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
4916
** interfaces.
4917
*/
4918
SQLITE_API void *sqlite3_update_hook(
4919
  sqlite3*, 
4920
  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
4921
  void*
4922
);
4923

    
4924
/*
4925
** CAPI3REF: Enable Or Disable Shared Pager Cache
4926
**
4927
** ^(This routine enables or disables the sharing of the database cache
4928
** and schema data structures between [database connection | connections]
4929
** to the same database. Sharing is enabled if the argument is true
4930
** and disabled if the argument is false.)^
4931
**
4932
** ^Cache sharing is enabled and disabled for an entire process.
4933
** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
4934
** sharing was enabled or disabled for each thread separately.
4935
**
4936
** ^(The cache sharing mode set by this interface effects all subsequent
4937
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
4938
** Existing database connections continue use the sharing mode
4939
** that was in effect at the time they were opened.)^
4940
**
4941
** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
4942
** successfully.  An [error code] is returned otherwise.)^
4943
**
4944
** ^Shared cache is disabled by default. But this might change in
4945
** future releases of SQLite.  Applications that care about shared
4946
** cache setting should set it explicitly.
4947
**
4948
** This interface is threadsafe on processors where writing a
4949
** 32-bit integer is atomic.
4950
**
4951
** See Also:  [SQLite Shared-Cache Mode]
4952
*/
4953
SQLITE_API int sqlite3_enable_shared_cache(int);
4954

    
4955
/*
4956
** CAPI3REF: Attempt To Free Heap Memory
4957
**
4958
** ^The sqlite3_release_memory() interface attempts to free N bytes
4959
** of heap memory by deallocating non-essential memory allocations
4960
** held by the database library.   Memory used to cache database
4961
** pages to improve performance is an example of non-essential memory.
4962
** ^sqlite3_release_memory() returns the number of bytes actually freed,
4963
** which might be more or less than the amount requested.
4964
** ^The sqlite3_release_memory() routine is a no-op returning zero
4965
** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
4966
**
4967
** See also: [sqlite3_db_release_memory()]
4968
*/
4969
SQLITE_API int sqlite3_release_memory(int);
4970

    
4971
/*
4972
** CAPI3REF: Free Memory Used By A Database Connection
4973
**
4974
** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
4975
** memory as possible from database connection D. Unlike the
4976
** [sqlite3_release_memory()] interface, this interface is in effect even
4977
** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
4978
** omitted.
4979
**
4980
** See also: [sqlite3_release_memory()]
4981
*/
4982
SQLITE_API int sqlite3_db_release_memory(sqlite3*);
4983

    
4984
/*
4985
** CAPI3REF: Impose A Limit On Heap Size
4986
**
4987
** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
4988
** soft limit on the amount of heap memory that may be allocated by SQLite.
4989
** ^SQLite strives to keep heap memory utilization below the soft heap
4990
** limit by reducing the number of pages held in the page cache
4991
** as heap memory usages approaches the limit.
4992
** ^The soft heap limit is "soft" because even though SQLite strives to stay
4993
** below the limit, it will exceed the limit rather than generate
4994
** an [SQLITE_NOMEM] error.  In other words, the soft heap limit 
4995
** is advisory only.
4996
**
4997
** ^The return value from sqlite3_soft_heap_limit64() is the size of
4998
** the soft heap limit prior to the call, or negative in the case of an
4999
** error.  ^If the argument N is negative
5000
** then no change is made to the soft heap limit.  Hence, the current
5001
** size of the soft heap limit can be determined by invoking
5002
** sqlite3_soft_heap_limit64() with a negative argument.
5003
**
5004
** ^If the argument N is zero then the soft heap limit is disabled.
5005
**
5006
** ^(The soft heap limit is not enforced in the current implementation
5007
** if one or more of following conditions are true:
5008
**
5009
** <ul>
5010
** <li> The soft heap limit is set to zero.
5011
** <li> Memory accounting is disabled using a combination of the
5012
**      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5013
**      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
5014
** <li> An alternative page cache implementation is specified using
5015
**      [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
5016
** <li> The page cache allocates from its own memory pool supplied
5017
**      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5018
**      from the heap.
5019
** </ul>)^
5020
**
5021
** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
5022
** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5023
** compile-time option is invoked.  With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5024
** the soft heap limit is enforced on every memory allocation.  Without
5025
** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5026
** when memory is allocated by the page cache.  Testing suggests that because
5027
** the page cache is the predominate memory user in SQLite, most
5028
** applications will achieve adequate soft heap limit enforcement without
5029
** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5030
**
5031
** The circumstances under which SQLite will enforce the soft heap limit may
5032
** changes in future releases of SQLite.
5033
*/
5034
SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
5035

    
5036
/*
5037
** CAPI3REF: Deprecated Soft Heap Limit Interface
5038
** DEPRECATED
5039
**
5040
** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5041
** interface.  This routine is provided for historical compatibility
5042
** only.  All new applications should use the
5043
** [sqlite3_soft_heap_limit64()] interface rather than this one.
5044
*/
5045
SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
5046

    
5047

    
5048
/*
5049
** CAPI3REF: Extract Metadata About A Column Of A Table
5050
**
5051
** ^This routine returns metadata about a specific column of a specific
5052
** database table accessible using the [database connection] handle
5053
** passed as the first function argument.
5054
**
5055
** ^The column is identified by the second, third and fourth parameters to
5056
** this function. ^The second parameter is either the name of the database
5057
** (i.e. "main", "temp", or an attached database) containing the specified
5058
** table or NULL. ^If it is NULL, then all attached databases are searched
5059
** for the table using the same algorithm used by the database engine to
5060
** resolve unqualified table references.
5061
**
5062
** ^The third and fourth parameters to this function are the table and column
5063
** name of the desired column, respectively. Neither of these parameters
5064
** may be NULL.
5065
**
5066
** ^Metadata is returned by writing to the memory locations passed as the 5th
5067
** and subsequent parameters to this function. ^Any of these arguments may be
5068
** NULL, in which case the corresponding element of metadata is omitted.
5069
**
5070
** ^(<blockquote>
5071
** <table border="1">
5072
** <tr><th> Parameter <th> Output<br>Type <th>  Description
5073
**
5074
** <tr><td> 5th <td> const char* <td> Data type
5075
** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5076
** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
5077
** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
5078
** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
5079
** </table>
5080
** </blockquote>)^
5081
**
5082
** ^The memory pointed to by the character pointers returned for the
5083
** declaration type and collation sequence is valid only until the next
5084
** call to any SQLite API function.
5085
**
5086
** ^If the specified table is actually a view, an [error code] is returned.
5087
**
5088
** ^If the specified column is "rowid", "oid" or "_rowid_" and an
5089
** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5090
** parameters are set for the explicitly declared column. ^(If there is no
5091
** explicitly declared [INTEGER PRIMARY KEY] column, then the output
5092
** parameters are set as follows:
5093
**
5094
** <pre>
5095
**     data type: "INTEGER"
5096
**     collation sequence: "BINARY"
5097
**     not null: 0
5098
**     primary key: 1
5099
**     auto increment: 0
5100
** </pre>)^
5101
**
5102
** ^(This function may load one or more schemas from database files. If an
5103
** error occurs during this process, or if the requested table or column
5104
** cannot be found, an [error code] is returned and an error message left
5105
** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
5106
**
5107
** ^This API is only available if the library was compiled with the
5108
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
5109
*/
5110
SQLITE_API int sqlite3_table_column_metadata(
5111
  sqlite3 *db,                /* Connection handle */
5112
  const char *zDbName,        /* Database name or NULL */
5113
  const char *zTableName,     /* Table name */
5114
  const char *zColumnName,    /* Column name */
5115
  char const **pzDataType,    /* OUTPUT: Declared data type */
5116
  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
5117
  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
5118
  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
5119
  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
5120
);
5121

    
5122
/*
5123
** CAPI3REF: Load An Extension
5124
**
5125
** ^This interface loads an SQLite extension library from the named file.
5126
**
5127
** ^The sqlite3_load_extension() interface attempts to load an
5128
** [SQLite extension] library contained in the file zFile.  If
5129
** the file cannot be loaded directly, attempts are made to load
5130
** with various operating-system specific extensions added.
5131
** So for example, if "samplelib" cannot be loaded, then names like
5132
** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
5133
** be tried also.
5134
**
5135
** ^The entry point is zProc.
5136
** ^(zProc may be 0, in which case SQLite will try to come up with an
5137
** entry point name on its own.  It first tries "sqlite3_extension_init".
5138
** If that does not work, it constructs a name "sqlite3_X_init" where the
5139
** X is consists of the lower-case equivalent of all ASCII alphabetic
5140
** characters in the filename from the last "/" to the first following
5141
** "." and omitting any initial "lib".)^
5142
** ^The sqlite3_load_extension() interface returns
5143
** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5144
** ^If an error occurs and pzErrMsg is not 0, then the
5145
** [sqlite3_load_extension()] interface shall attempt to
5146
** fill *pzErrMsg with error message text stored in memory
5147
** obtained from [sqlite3_malloc()]. The calling function
5148
** should free this memory by calling [sqlite3_free()].
5149
**
5150
** ^Extension loading must be enabled using
5151
** [sqlite3_enable_load_extension()] prior to calling this API,
5152
** otherwise an error will be returned.
5153
**
5154
** See also the [load_extension() SQL function].
5155
*/
5156
SQLITE_API int sqlite3_load_extension(
5157
  sqlite3 *db,          /* Load the extension into this database connection */
5158
  const char *zFile,    /* Name of the shared library containing extension */
5159
  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
5160
  char **pzErrMsg       /* Put error message here if not 0 */
5161
);
5162

    
5163
/*
5164
** CAPI3REF: Enable Or Disable Extension Loading
5165
**
5166
** ^So as not to open security holes in older applications that are
5167
** unprepared to deal with [extension loading], and as a means of disabling
5168
** [extension loading] while evaluating user-entered SQL, the following API
5169
** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5170
**
5171
** ^Extension loading is off by default.
5172
** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5173
** to turn extension loading on and call it with onoff==0 to turn
5174
** it back off again.
5175
*/
5176
SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5177

    
5178
/*
5179
** CAPI3REF: Automatically Load Statically Linked Extensions
5180
**
5181
** ^This interface causes the xEntryPoint() function to be invoked for
5182
** each new [database connection] that is created.  The idea here is that
5183
** xEntryPoint() is the entry point for a statically linked [SQLite extension]
5184
** that is to be automatically loaded into all new database connections.
5185
**
5186
** ^(Even though the function prototype shows that xEntryPoint() takes
5187
** no arguments and returns void, SQLite invokes xEntryPoint() with three
5188
** arguments and expects and integer result as if the signature of the
5189
** entry point where as follows:
5190
**
5191
** <blockquote><pre>
5192
** &nbsp;  int xEntryPoint(
5193
** &nbsp;    sqlite3 *db,
5194
** &nbsp;    const char **pzErrMsg,
5195
** &nbsp;    const struct sqlite3_api_routines *pThunk
5196
** &nbsp;  );
5197
** </pre></blockquote>)^
5198
**
5199
** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5200
** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5201
** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
5202
** is NULL before calling the xEntryPoint().  ^SQLite will invoke
5203
** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
5204
** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5205
** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5206
**
5207
** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5208
** on the list of automatic extensions is a harmless no-op. ^No entry point
5209
** will be called more than once for each database connection that is opened.
5210
**
5211
** See also: [sqlite3_reset_auto_extension()]
5212
** and [sqlite3_cancel_auto_extension()]
5213
*/
5214
SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
5215

    
5216
/*
5217
** CAPI3REF: Cancel Automatic Extension Loading
5218
**
5219
** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
5220
** initialization routine X that was registered using a prior call to
5221
** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]
5222
** routine returns 1 if initialization routine X was successfully 
5223
** unregistered and it returns 0 if X was not on the list of initialization
5224
** routines.
5225
*/
5226
SQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void));
5227

    
5228
/*
5229
** CAPI3REF: Reset Automatic Extension Loading
5230
**
5231
** ^This interface disables all automatic extensions previously
5232
** registered using [sqlite3_auto_extension()].
5233
*/
5234
SQLITE_API void sqlite3_reset_auto_extension(void);
5235

    
5236
/*
5237
** The interface to the virtual-table mechanism is currently considered
5238
** to be experimental.  The interface might change in incompatible ways.
5239
** If this is a problem for you, do not use the interface at this time.
5240
**
5241
** When the virtual-table mechanism stabilizes, we will declare the
5242
** interface fixed, support it indefinitely, and remove this comment.
5243
*/
5244

    
5245
/*
5246
** Structures used by the virtual table interface
5247
*/
5248
typedef struct sqlite3_vtab sqlite3_vtab;
5249
typedef struct sqlite3_index_info sqlite3_index_info;
5250
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5251
typedef struct sqlite3_module sqlite3_module;
5252

    
5253
/*
5254
** CAPI3REF: Virtual Table Object
5255
** KEYWORDS: sqlite3_module {virtual table module}
5256
**
5257
** This structure, sometimes called a "virtual table module", 
5258
** defines the implementation of a [virtual tables].  
5259
** This structure consists mostly of methods for the module.
5260
**
5261
** ^A virtual table module is created by filling in a persistent
5262
** instance of this structure and passing a pointer to that instance
5263
** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5264
** ^The registration remains valid until it is replaced by a different
5265
** module or until the [database connection] closes.  The content
5266
** of this structure must not change while it is registered with
5267
** any database connection.
5268
*/
5269
struct sqlite3_module {
5270
  int iVersion;
5271
  int (*xCreate)(sqlite3*, void *pAux,
5272
               int argc, const char *const*argv,
5273
               sqlite3_vtab **ppVTab, char**);
5274
  int (*xConnect)(sqlite3*, void *pAux,
5275
               int argc, const char *const*argv,
5276
               sqlite3_vtab **ppVTab, char**);
5277
  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5278
  int (*xDisconnect)(sqlite3_vtab *pVTab);
5279
  int (*xDestroy)(sqlite3_vtab *pVTab);
5280
  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5281
  int (*xClose)(sqlite3_vtab_cursor*);
5282
  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5283
                int argc, sqlite3_value **argv);
5284
  int (*xNext)(sqlite3_vtab_cursor*);
5285
  int (*xEof)(sqlite3_vtab_cursor*);
5286
  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5287
  int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5288
  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5289
  int (*xBegin)(sqlite3_vtab *pVTab);
5290
  int (*xSync)(sqlite3_vtab *pVTab);
5291
  int (*xCommit)(sqlite3_vtab *pVTab);
5292
  int (*xRollback)(sqlite3_vtab *pVTab);
5293
  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5294
                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5295
                       void **ppArg);
5296
  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5297
  /* The methods above are in version 1 of the sqlite_module object. Those 
5298
  ** below are for version 2 and greater. */
5299
  int (*xSavepoint)(sqlite3_vtab *pVTab, int);
5300
  int (*xRelease)(sqlite3_vtab *pVTab, int);
5301
  int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5302
};
5303

    
5304
/*
5305
** CAPI3REF: Virtual Table Indexing Information
5306
** KEYWORDS: sqlite3_index_info
5307
**
5308
** The sqlite3_index_info structure and its substructures is used as part
5309
** of the [virtual table] interface to
5310
** pass information into and receive the reply from the [xBestIndex]
5311
** method of a [virtual table module].  The fields under **Inputs** are the
5312
** inputs to xBestIndex and are read-only.  xBestIndex inserts its
5313
** results into the **Outputs** fields.
5314
**
5315
** ^(The aConstraint[] array records WHERE clause constraints of the form:
5316
**
5317
** <blockquote>column OP expr</blockquote>
5318
**
5319
** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
5320
** stored in aConstraint[].op using one of the
5321
** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
5322
** ^(The index of the column is stored in
5323
** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
5324
** expr on the right-hand side can be evaluated (and thus the constraint
5325
** is usable) and false if it cannot.)^
5326
**
5327
** ^The optimizer automatically inverts terms of the form "expr OP column"
5328
** and makes other simplifications to the WHERE clause in an attempt to
5329
** get as many WHERE clause terms into the form shown above as possible.
5330
** ^The aConstraint[] array only reports WHERE clause terms that are
5331
** relevant to the particular virtual table being queried.
5332
**
5333
** ^Information about the ORDER BY clause is stored in aOrderBy[].
5334
** ^Each term of aOrderBy records a column of the ORDER BY clause.
5335
**
5336
** The [xBestIndex] method must fill aConstraintUsage[] with information
5337
** about what parameters to pass to xFilter.  ^If argvIndex>0 then
5338
** the right-hand side of the corresponding aConstraint[] is evaluated
5339
** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
5340
** is true, then the constraint is assumed to be fully handled by the
5341
** virtual table and is not checked again by SQLite.)^
5342
**
5343
** ^The idxNum and idxPtr values are recorded and passed into the
5344
** [xFilter] method.
5345
** ^[sqlite3_free()] is used to free idxPtr if and only if
5346
** needToFreeIdxPtr is true.
5347
**
5348
** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5349
** the correct order to satisfy the ORDER BY clause so that no separate
5350
** sorting step is required.
5351
**
5352
** ^The estimatedCost value is an estimate of the cost of a particular
5353
** strategy. A cost of N indicates that the cost of the strategy is similar
5354
** to a linear scan of an SQLite table with N rows. A cost of log(N) 
5355
** indicates that the expense of the operation is similar to that of a
5356
** binary search on a unique indexed field of an SQLite table with N rows.
5357
**
5358
** ^The estimatedRows value is an estimate of the number of rows that
5359
** will be returned by the strategy.
5360
**
5361
** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
5362
** structure for SQLite version 3.8.2. If a virtual table extension is
5363
** used with an SQLite version earlier than 3.8.2, the results of attempting 
5364
** to read or write the estimatedRows field are undefined (but are likely 
5365
** to included crashing the application). The estimatedRows field should
5366
** therefore only be used if [sqlite3_libversion_number()] returns a
5367
** value greater than or equal to 3008002.
5368
*/
5369
struct sqlite3_index_info {
5370
  /* Inputs */
5371
  int nConstraint;           /* Number of entries in aConstraint */
5372
  struct sqlite3_index_constraint {
5373
     int iColumn;              /* Column on left-hand side of constraint */
5374
     unsigned char op;         /* Constraint operator */
5375
     unsigned char usable;     /* True if this constraint is usable */
5376
     int iTermOffset;          /* Used internally - xBestIndex should ignore */
5377
  } *aConstraint;            /* Table of WHERE clause constraints */
5378
  int nOrderBy;              /* Number of terms in the ORDER BY clause */
5379
  struct sqlite3_index_orderby {
5380
     int iColumn;              /* Column number */
5381
     unsigned char desc;       /* True for DESC.  False for ASC. */
5382
  } *aOrderBy;               /* The ORDER BY clause */
5383
  /* Outputs */
5384
  struct sqlite3_index_constraint_usage {
5385
    int argvIndex;           /* if >0, constraint is part of argv to xFilter */
5386
    unsigned char omit;      /* Do not code a test for this constraint */
5387
  } *aConstraintUsage;
5388
  int idxNum;                /* Number used to identify the index */
5389
  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
5390
  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
5391
  int orderByConsumed;       /* True if output is already ordered */
5392
  double estimatedCost;           /* Estimated cost of using this index */
5393
  /* Fields below are only available in SQLite 3.8.2 and later */
5394
  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
5395
};
5396

    
5397
/*
5398
** CAPI3REF: Virtual Table Constraint Operator Codes
5399
**
5400
** These macros defined the allowed values for the
5401
** [sqlite3_index_info].aConstraint[].op field.  Each value represents
5402
** an operator that is part of a constraint term in the wHERE clause of
5403
** a query that uses a [virtual table].
5404
*/
5405
#define SQLITE_INDEX_CONSTRAINT_EQ    2
5406
#define SQLITE_INDEX_CONSTRAINT_GT    4
5407
#define SQLITE_INDEX_CONSTRAINT_LE    8
5408
#define SQLITE_INDEX_CONSTRAINT_LT    16
5409
#define SQLITE_INDEX_CONSTRAINT_GE    32
5410
#define SQLITE_INDEX_CONSTRAINT_MATCH 64
5411

    
5412
/*
5413
** CAPI3REF: Register A Virtual Table Implementation
5414
**
5415
** ^These routines are used to register a new [virtual table module] name.
5416
** ^Module names must be registered before
5417
** creating a new [virtual table] using the module and before using a
5418
** preexisting [virtual table] for the module.
5419
**
5420
** ^The module name is registered on the [database connection] specified
5421
** by the first parameter.  ^The name of the module is given by the 
5422
** second parameter.  ^The third parameter is a pointer to
5423
** the implementation of the [virtual table module].   ^The fourth
5424
** parameter is an arbitrary client data pointer that is passed through
5425
** into the [xCreate] and [xConnect] methods of the virtual table module
5426
** when a new virtual table is be being created or reinitialized.
5427
**
5428
** ^The sqlite3_create_module_v2() interface has a fifth parameter which
5429
** is a pointer to a destructor for the pClientData.  ^SQLite will
5430
** invoke the destructor function (if it is not NULL) when SQLite
5431
** no longer needs the pClientData pointer.  ^The destructor will also
5432
** be invoked if the call to sqlite3_create_module_v2() fails.
5433
** ^The sqlite3_create_module()
5434
** interface is equivalent to sqlite3_create_module_v2() with a NULL
5435
** destructor.
5436
*/
5437
SQLITE_API int sqlite3_create_module(
5438
  sqlite3 *db,               /* SQLite connection to register module with */
5439
  const char *zName,         /* Name of the module */
5440
  const sqlite3_module *p,   /* Methods for the module */
5441
  void *pClientData          /* Client data for xCreate/xConnect */
5442
);
5443
SQLITE_API int sqlite3_create_module_v2(
5444
  sqlite3 *db,               /* SQLite connection to register module with */
5445
  const char *zName,         /* Name of the module */
5446
  const sqlite3_module *p,   /* Methods for the module */
5447
  void *pClientData,         /* Client data for xCreate/xConnect */
5448
  void(*xDestroy)(void*)     /* Module destructor function */
5449
);
5450

    
5451
/*
5452
** CAPI3REF: Virtual Table Instance Object
5453
** KEYWORDS: sqlite3_vtab
5454
**
5455
** Every [virtual table module] implementation uses a subclass
5456
** of this object to describe a particular instance
5457
** of the [virtual table].  Each subclass will
5458
** be tailored to the specific needs of the module implementation.
5459
** The purpose of this superclass is to define certain fields that are
5460
** common to all module implementations.
5461
**
5462
** ^Virtual tables methods can set an error message by assigning a
5463
** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
5464
** take care that any prior string is freed by a call to [sqlite3_free()]
5465
** prior to assigning a new string to zErrMsg.  ^After the error message
5466
** is delivered up to the client application, the string will be automatically
5467
** freed by sqlite3_free() and the zErrMsg field will be zeroed.
5468
*/
5469
struct sqlite3_vtab {
5470
  const sqlite3_module *pModule;  /* The module for this virtual table */
5471
  int nRef;                       /* NO LONGER USED */
5472
  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
5473
  /* Virtual table implementations will typically add additional fields */
5474
};
5475

    
5476
/*
5477
** CAPI3REF: Virtual Table Cursor Object
5478
** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
5479
**
5480
** Every [virtual table module] implementation uses a subclass of the
5481
** following structure to describe cursors that point into the
5482
** [virtual table] and are used
5483
** to loop through the virtual table.  Cursors are created using the
5484
** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
5485
** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
5486
** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
5487
** of the module.  Each module implementation will define
5488
** the content of a cursor structure to suit its own needs.
5489
**
5490
** This superclass exists in order to define fields of the cursor that
5491
** are common to all implementations.
5492
*/
5493
struct sqlite3_vtab_cursor {
5494
  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
5495
  /* Virtual table implementations will typically add additional fields */
5496
};
5497

    
5498
/*
5499
** CAPI3REF: Declare The Schema Of A Virtual Table
5500
**
5501
** ^The [xCreate] and [xConnect] methods of a
5502
** [virtual table module] call this interface
5503
** to declare the format (the names and datatypes of the columns) of
5504
** the virtual tables they implement.
5505
*/
5506
SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
5507

    
5508
/*
5509
** CAPI3REF: Overload A Function For A Virtual Table
5510
**
5511
** ^(Virtual tables can provide alternative implementations of functions
5512
** using the [xFindFunction] method of the [virtual table module].  
5513
** But global versions of those functions
5514
** must exist in order to be overloaded.)^
5515
**
5516
** ^(This API makes sure a global version of a function with a particular
5517
** name and number of parameters exists.  If no such function exists
5518
** before this API is called, a new function is created.)^  ^The implementation
5519
** of the new function always causes an exception to be thrown.  So
5520
** the new function is not good for anything by itself.  Its only
5521
** purpose is to be a placeholder function that can be overloaded
5522
** by a [virtual table].
5523
*/
5524
SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
5525

    
5526
/*
5527
** The interface to the virtual-table mechanism defined above (back up
5528
** to a comment remarkably similar to this one) is currently considered
5529
** to be experimental.  The interface might change in incompatible ways.
5530
** If this is a problem for you, do not use the interface at this time.
5531
**
5532
** When the virtual-table mechanism stabilizes, we will declare the
5533
** interface fixed, support it indefinitely, and remove this comment.
5534
*/
5535

    
5536
/*
5537
** CAPI3REF: A Handle To An Open BLOB
5538
** KEYWORDS: {BLOB handle} {BLOB handles}
5539
**
5540
** An instance of this object represents an open BLOB on which
5541
** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5542
** ^Objects of this type are created by [sqlite3_blob_open()]
5543
** and destroyed by [sqlite3_blob_close()].
5544
** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5545
** can be used to read or write small subsections of the BLOB.
5546
** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5547
*/
5548
typedef struct sqlite3_blob sqlite3_blob;
5549

    
5550
/*
5551
** CAPI3REF: Open A BLOB For Incremental I/O
5552
**
5553
** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
5554
** in row iRow, column zColumn, table zTable in database zDb;
5555
** in other words, the same BLOB that would be selected by:
5556
**
5557
** <pre>
5558
**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
5559
** </pre>)^
5560
**
5561
** ^If the flags parameter is non-zero, then the BLOB is opened for read
5562
** and write access. ^If it is zero, the BLOB is opened for read access.
5563
** ^It is not possible to open a column that is part of an index or primary 
5564
** key for writing. ^If [foreign key constraints] are enabled, it is 
5565
** not possible to open a column that is part of a [child key] for writing.
5566
**
5567
** ^Note that the database name is not the filename that contains
5568
** the database but rather the symbolic name of the database that
5569
** appears after the AS keyword when the database is connected using [ATTACH].
5570
** ^For the main database file, the database name is "main".
5571
** ^For TEMP tables, the database name is "temp".
5572
**
5573
** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
5574
** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
5575
** to be a null pointer.)^
5576
** ^This function sets the [database connection] error code and message
5577
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
5578
** functions. ^Note that the *ppBlob variable is always initialized in a
5579
** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
5580
** regardless of the success or failure of this routine.
5581
**
5582
** ^(If the row that a BLOB handle points to is modified by an
5583
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
5584
** then the BLOB handle is marked as "expired".
5585
** This is true if any column of the row is changed, even a column
5586
** other than the one the BLOB handle is open on.)^
5587
** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
5588
** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
5589
** ^(Changes written into a BLOB prior to the BLOB expiring are not
5590
** rolled back by the expiration of the BLOB.  Such changes will eventually
5591
** commit if the transaction continues to completion.)^
5592
**
5593
** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
5594
** the opened blob.  ^The size of a blob may not be changed by this
5595
** interface.  Use the [UPDATE] SQL command to change the size of a
5596
** blob.
5597
**
5598
** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID]
5599
** table.  Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables.
5600
**
5601
** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
5602
** and the built-in [zeroblob] SQL function can be used, if desired,
5603
** to create an empty, zero-filled blob in which to read or write using
5604
** this interface.
5605
**
5606
** To avoid a resource leak, every open [BLOB handle] should eventually
5607
** be released by a call to [sqlite3_blob_close()].
5608
*/
5609
SQLITE_API int sqlite3_blob_open(
5610
  sqlite3*,
5611
  const char *zDb,
5612
  const char *zTable,
5613
  const char *zColumn,
5614
  sqlite3_int64 iRow,
5615
  int flags,
5616
  sqlite3_blob **ppBlob
5617
);
5618

    
5619
/*
5620
** CAPI3REF: Move a BLOB Handle to a New Row
5621
**
5622
** ^This function is used to move an existing blob handle so that it points
5623
** to a different row of the same database table. ^The new row is identified
5624
** by the rowid value passed as the second argument. Only the row can be
5625
** changed. ^The database, table and column on which the blob handle is open
5626
** remain the same. Moving an existing blob handle to a new row can be
5627
** faster than closing the existing handle and opening a new one.
5628
**
5629
** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
5630
** it must exist and there must be either a blob or text value stored in
5631
** the nominated column.)^ ^If the new row is not present in the table, or if
5632
** it does not contain a blob or text value, or if another error occurs, an
5633
** SQLite error code is returned and the blob handle is considered aborted.
5634
** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
5635
** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
5636
** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
5637
** always returns zero.
5638
**
5639
** ^This function sets the database handle error code and message.
5640
*/
5641
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
5642

    
5643
/*
5644
** CAPI3REF: Close A BLOB Handle
5645
**
5646
** ^Closes an open [BLOB handle].
5647
**
5648
** ^Closing a BLOB shall cause the current transaction to commit
5649
** if there are no other BLOBs, no pending prepared statements, and the
5650
** database connection is in [autocommit mode].
5651
** ^If any writes were made to the BLOB, they might be held in cache
5652
** until the close operation if they will fit.
5653
**
5654
** ^(Closing the BLOB often forces the changes
5655
** out to disk and so if any I/O errors occur, they will likely occur
5656
** at the time when the BLOB is closed.  Any errors that occur during
5657
** closing are reported as a non-zero return value.)^
5658
**
5659
** ^(The BLOB is closed unconditionally.  Even if this routine returns
5660
** an error code, the BLOB is still closed.)^
5661
**
5662
** ^Calling this routine with a null pointer (such as would be returned
5663
** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
5664
*/
5665
SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
5666

    
5667
/*
5668
** CAPI3REF: Return The Size Of An Open BLOB
5669
**
5670
** ^Returns the size in bytes of the BLOB accessible via the 
5671
** successfully opened [BLOB handle] in its only argument.  ^The
5672
** incremental blob I/O routines can only read or overwriting existing
5673
** blob content; they cannot change the size of a blob.
5674
**
5675
** This routine only works on a [BLOB handle] which has been created
5676
** by a prior successful call to [sqlite3_blob_open()] and which has not
5677
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5678
** to this routine results in undefined and probably undesirable behavior.
5679
*/
5680
SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
5681

    
5682
/*
5683
** CAPI3REF: Read Data From A BLOB Incrementally
5684
**
5685
** ^(This function is used to read data from an open [BLOB handle] into a
5686
** caller-supplied buffer. N bytes of data are copied into buffer Z
5687
** from the open BLOB, starting at offset iOffset.)^
5688
**
5689
** ^If offset iOffset is less than N bytes from the end of the BLOB,
5690
** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
5691
** less than zero, [SQLITE_ERROR] is returned and no data is read.
5692
** ^The size of the blob (and hence the maximum value of N+iOffset)
5693
** can be determined using the [sqlite3_blob_bytes()] interface.
5694
**
5695
** ^An attempt to read from an expired [BLOB handle] fails with an
5696
** error code of [SQLITE_ABORT].
5697
**
5698
** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
5699
** Otherwise, an [error code] or an [extended error code] is returned.)^
5700
**
5701
** This routine only works on a [BLOB handle] which has been created
5702
** by a prior successful call to [sqlite3_blob_open()] and which has not
5703
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5704
** to this routine results in undefined and probably undesirable behavior.
5705
**
5706
** See also: [sqlite3_blob_write()].
5707
*/
5708
SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
5709

    
5710
/*
5711
** CAPI3REF: Write Data Into A BLOB Incrementally
5712
**
5713
** ^This function is used to write data into an open [BLOB handle] from a
5714
** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
5715
** into the open BLOB, starting at offset iOffset.
5716
**
5717
** ^If the [BLOB handle] passed as the first argument was not opened for
5718
** writing (the flags parameter to [sqlite3_blob_open()] was zero),
5719
** this function returns [SQLITE_READONLY].
5720
**
5721
** ^This function may only modify the contents of the BLOB; it is
5722
** not possible to increase the size of a BLOB using this API.
5723
** ^If offset iOffset is less than N bytes from the end of the BLOB,
5724
** [SQLITE_ERROR] is returned and no data is written.  ^If N is
5725
** less than zero [SQLITE_ERROR] is returned and no data is written.
5726
** The size of the BLOB (and hence the maximum value of N+iOffset)
5727
** can be determined using the [sqlite3_blob_bytes()] interface.
5728
**
5729
** ^An attempt to write to an expired [BLOB handle] fails with an
5730
** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
5731
** before the [BLOB handle] expired are not rolled back by the
5732
** expiration of the handle, though of course those changes might
5733
** have been overwritten by the statement that expired the BLOB handle
5734
** or by other independent statements.
5735
**
5736
** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
5737
** Otherwise, an  [error code] or an [extended error code] is returned.)^
5738
**
5739
** This routine only works on a [BLOB handle] which has been created
5740
** by a prior successful call to [sqlite3_blob_open()] and which has not
5741
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5742
** to this routine results in undefined and probably undesirable behavior.
5743
**
5744
** See also: [sqlite3_blob_read()].
5745
*/
5746
SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
5747

    
5748
/*
5749
** CAPI3REF: Virtual File System Objects
5750
**
5751
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
5752
** that SQLite uses to interact
5753
** with the underlying operating system.  Most SQLite builds come with a
5754
** single default VFS that is appropriate for the host computer.
5755
** New VFSes can be registered and existing VFSes can be unregistered.
5756
** The following interfaces are provided.
5757
**
5758
** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
5759
** ^Names are case sensitive.
5760
** ^Names are zero-terminated UTF-8 strings.
5761
** ^If there is no match, a NULL pointer is returned.
5762
** ^If zVfsName is NULL then the default VFS is returned.
5763
**
5764
** ^New VFSes are registered with sqlite3_vfs_register().
5765
** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
5766
** ^The same VFS can be registered multiple times without injury.
5767
** ^To make an existing VFS into the default VFS, register it again
5768
** with the makeDflt flag set.  If two different VFSes with the
5769
** same name are registered, the behavior is undefined.  If a
5770
** VFS is registered with a name that is NULL or an empty string,
5771
** then the behavior is undefined.
5772
**
5773
** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
5774
** ^(If the default VFS is unregistered, another VFS is chosen as
5775
** the default.  The choice for the new VFS is arbitrary.)^
5776
*/
5777
SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
5778
SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
5779
SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
5780

    
5781
/*
5782
** CAPI3REF: Mutexes
5783
**
5784
** The SQLite core uses these routines for thread
5785
** synchronization. Though they are intended for internal
5786
** use by SQLite, code that links against SQLite is
5787
** permitted to use any of these routines.
5788
**
5789
** The SQLite source code contains multiple implementations
5790
** of these mutex routines.  An appropriate implementation
5791
** is selected automatically at compile-time.  ^(The following
5792
** implementations are available in the SQLite core:
5793
**
5794
** <ul>
5795
** <li>   SQLITE_MUTEX_PTHREADS
5796
** <li>   SQLITE_MUTEX_W32
5797
** <li>   SQLITE_MUTEX_NOOP
5798
** </ul>)^
5799
**
5800
** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
5801
** that does no real locking and is appropriate for use in
5802
** a single-threaded application.  ^The SQLITE_MUTEX_PTHREADS and
5803
** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
5804
** and Windows.
5805
**
5806
** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
5807
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
5808
** implementation is included with the library. In this case the
5809
** application must supply a custom mutex implementation using the
5810
** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
5811
** before calling sqlite3_initialize() or any other public sqlite3_
5812
** function that calls sqlite3_initialize().)^
5813
**
5814
** ^The sqlite3_mutex_alloc() routine allocates a new
5815
** mutex and returns a pointer to it. ^If it returns NULL
5816
** that means that a mutex could not be allocated.  ^SQLite
5817
** will unwind its stack and return an error.  ^(The argument
5818
** to sqlite3_mutex_alloc() is one of these integer constants:
5819
**
5820
** <ul>
5821
** <li>  SQLITE_MUTEX_FAST
5822
** <li>  SQLITE_MUTEX_RECURSIVE
5823
** <li>  SQLITE_MUTEX_STATIC_MASTER
5824
** <li>  SQLITE_MUTEX_STATIC_MEM
5825
** <li>  SQLITE_MUTEX_STATIC_MEM2
5826
** <li>  SQLITE_MUTEX_STATIC_PRNG
5827
** <li>  SQLITE_MUTEX_STATIC_LRU
5828
** <li>  SQLITE_MUTEX_STATIC_LRU2
5829
** </ul>)^
5830
**
5831
** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
5832
** cause sqlite3_mutex_alloc() to create
5833
** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
5834
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
5835
** The mutex implementation does not need to make a distinction
5836
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
5837
** not want to.  ^SQLite will only request a recursive mutex in
5838
** cases where it really needs one.  ^If a faster non-recursive mutex
5839
** implementation is available on the host platform, the mutex subsystem
5840
** might return such a mutex in response to SQLITE_MUTEX_FAST.
5841
**
5842
** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
5843
** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
5844
** a pointer to a static preexisting mutex.  ^Six static mutexes are
5845
** used by the current version of SQLite.  Future versions of SQLite
5846
** may add additional static mutexes.  Static mutexes are for internal
5847
** use by SQLite only.  Applications that use SQLite mutexes should
5848
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
5849
** SQLITE_MUTEX_RECURSIVE.
5850
**
5851
** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
5852
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
5853
** returns a different mutex on every call.  ^But for the static
5854
** mutex types, the same mutex is returned on every call that has
5855
** the same type number.
5856
**
5857
** ^The sqlite3_mutex_free() routine deallocates a previously
5858
** allocated dynamic mutex.  ^SQLite is careful to deallocate every
5859
** dynamic mutex that it allocates.  The dynamic mutexes must not be in
5860
** use when they are deallocated.  Attempting to deallocate a static
5861
** mutex results in undefined behavior.  ^SQLite never deallocates
5862
** a static mutex.
5863
**
5864
** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
5865
** to enter a mutex.  ^If another thread is already within the mutex,
5866
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
5867
** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
5868
** upon successful entry.  ^(Mutexes created using
5869
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
5870
** In such cases the,
5871
** mutex must be exited an equal number of times before another thread
5872
** can enter.)^  ^(If the same thread tries to enter any other
5873
** kind of mutex more than once, the behavior is undefined.
5874
** SQLite will never exhibit
5875
** such behavior in its own use of mutexes.)^
5876
**
5877
** ^(Some systems (for example, Windows 95) do not support the operation
5878
** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
5879
** will always return SQLITE_BUSY.  The SQLite core only ever uses
5880
** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
5881
**
5882
** ^The sqlite3_mutex_leave() routine exits a mutex that was
5883
** previously entered by the same thread.   ^(The behavior
5884
** is undefined if the mutex is not currently entered by the
5885
** calling thread or is not currently allocated.  SQLite will
5886
** never do either.)^
5887
**
5888
** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
5889
** sqlite3_mutex_leave() is a NULL pointer, then all three routines
5890
** behave as no-ops.
5891
**
5892
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
5893
*/
5894
SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
5895
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
5896
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
5897
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
5898
SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
5899

    
5900
/*
5901
** CAPI3REF: Mutex Methods Object
5902
**
5903
** An instance of this structure defines the low-level routines
5904
** used to allocate and use mutexes.
5905
**
5906
** Usually, the default mutex implementations provided by SQLite are
5907
** sufficient, however the user has the option of substituting a custom
5908
** implementation for specialized deployments or systems for which SQLite
5909
** does not provide a suitable implementation. In this case, the user
5910
** creates and populates an instance of this structure to pass
5911
** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
5912
** Additionally, an instance of this structure can be used as an
5913
** output variable when querying the system for the current mutex
5914
** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
5915
**
5916
** ^The xMutexInit method defined by this structure is invoked as
5917
** part of system initialization by the sqlite3_initialize() function.
5918
** ^The xMutexInit routine is called by SQLite exactly once for each
5919
** effective call to [sqlite3_initialize()].
5920
**
5921
** ^The xMutexEnd method defined by this structure is invoked as
5922
** part of system shutdown by the sqlite3_shutdown() function. The
5923
** implementation of this method is expected to release all outstanding
5924
** resources obtained by the mutex methods implementation, especially
5925
** those obtained by the xMutexInit method.  ^The xMutexEnd()
5926
** interface is invoked exactly once for each call to [sqlite3_shutdown()].
5927
**
5928
** ^(The remaining seven methods defined by this structure (xMutexAlloc,
5929
** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
5930
** xMutexNotheld) implement the following interfaces (respectively):
5931
**
5932
** <ul>
5933
**   <li>  [sqlite3_mutex_alloc()] </li>
5934
**   <li>  [sqlite3_mutex_free()] </li>
5935
**   <li>  [sqlite3_mutex_enter()] </li>
5936
**   <li>  [sqlite3_mutex_try()] </li>
5937
**   <li>  [sqlite3_mutex_leave()] </li>
5938
**   <li>  [sqlite3_mutex_held()] </li>
5939
**   <li>  [sqlite3_mutex_notheld()] </li>
5940
** </ul>)^
5941
**
5942
** The only difference is that the public sqlite3_XXX functions enumerated
5943
** above silently ignore any invocations that pass a NULL pointer instead
5944
** of a valid mutex handle. The implementations of the methods defined
5945
** by this structure are not required to handle this case, the results
5946
** of passing a NULL pointer instead of a valid mutex handle are undefined
5947
** (i.e. it is acceptable to provide an implementation that segfaults if
5948
** it is passed a NULL pointer).
5949
**
5950
** The xMutexInit() method must be threadsafe.  ^It must be harmless to
5951
** invoke xMutexInit() multiple times within the same process and without
5952
** intervening calls to xMutexEnd().  Second and subsequent calls to
5953
** xMutexInit() must be no-ops.
5954
**
5955
** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
5956
** and its associates).  ^Similarly, xMutexAlloc() must not use SQLite memory
5957
** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
5958
** memory allocation for a fast or recursive mutex.
5959
**
5960
** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
5961
** called, but only if the prior call to xMutexInit returned SQLITE_OK.
5962
** If xMutexInit fails in any way, it is expected to clean up after itself
5963
** prior to returning.
5964
*/
5965
typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
5966
struct sqlite3_mutex_methods {
5967
  int (*xMutexInit)(void);
5968
  int (*xMutexEnd)(void);
5969
  sqlite3_mutex *(*xMutexAlloc)(int);
5970
  void (*xMutexFree)(sqlite3_mutex *);
5971
  void (*xMutexEnter)(sqlite3_mutex *);
5972
  int (*xMutexTry)(sqlite3_mutex *);
5973
  void (*xMutexLeave)(sqlite3_mutex *);
5974
  int (*xMutexHeld)(sqlite3_mutex *);
5975
  int (*xMutexNotheld)(sqlite3_mutex *);
5976
};
5977

    
5978
/*
5979
** CAPI3REF: Mutex Verification Routines
5980
**
5981
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
5982
** are intended for use inside assert() statements.  ^The SQLite core
5983
** never uses these routines except inside an assert() and applications
5984
** are advised to follow the lead of the core.  ^The SQLite core only
5985
** provides implementations for these routines when it is compiled
5986
** with the SQLITE_DEBUG flag.  ^External mutex implementations
5987
** are only required to provide these routines if SQLITE_DEBUG is
5988
** defined and if NDEBUG is not defined.
5989
**
5990
** ^These routines should return true if the mutex in their argument
5991
** is held or not held, respectively, by the calling thread.
5992
**
5993
** ^The implementation is not required to provide versions of these
5994
** routines that actually work. If the implementation does not provide working
5995
** versions of these routines, it should at least provide stubs that always
5996
** return true so that one does not get spurious assertion failures.
5997
**
5998
** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
5999
** the routine should return 1.   This seems counter-intuitive since
6000
** clearly the mutex cannot be held if it does not exist.  But
6001
** the reason the mutex does not exist is because the build is not
6002
** using mutexes.  And we do not want the assert() containing the
6003
** call to sqlite3_mutex_held() to fail, so a non-zero return is
6004
** the appropriate thing to do.  ^The sqlite3_mutex_notheld()
6005
** interface should also return 1 when given a NULL pointer.
6006
*/
6007
#ifndef NDEBUG
6008
SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
6009
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
6010
#endif
6011

    
6012
/*
6013
** CAPI3REF: Mutex Types
6014
**
6015
** The [sqlite3_mutex_alloc()] interface takes a single argument
6016
** which is one of these integer constants.
6017
**
6018
** The set of static mutexes may change from one SQLite release to the
6019
** next.  Applications that override the built-in mutex logic must be
6020
** prepared to accommodate additional static mutexes.
6021
*/
6022
#define SQLITE_MUTEX_FAST             0
6023
#define SQLITE_MUTEX_RECURSIVE        1
6024
#define SQLITE_MUTEX_STATIC_MASTER    2
6025
#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
6026
#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
6027
#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
6028
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
6029
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
6030
#define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
6031
#define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
6032

    
6033
/*
6034
** CAPI3REF: Retrieve the mutex for a database connection
6035
**
6036
** ^This interface returns a pointer the [sqlite3_mutex] object that 
6037
** serializes access to the [database connection] given in the argument
6038
** when the [threading mode] is Serialized.
6039
** ^If the [threading mode] is Single-thread or Multi-thread then this
6040
** routine returns a NULL pointer.
6041
*/
6042
SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
6043

    
6044
/*
6045
** CAPI3REF: Low-Level Control Of Database Files
6046
**
6047
** ^The [sqlite3_file_control()] interface makes a direct call to the
6048
** xFileControl method for the [sqlite3_io_methods] object associated
6049
** with a particular database identified by the second argument. ^The
6050
** name of the database is "main" for the main database or "temp" for the
6051
** TEMP database, or the name that appears after the AS keyword for
6052
** databases that are added using the [ATTACH] SQL command.
6053
** ^A NULL pointer can be used in place of "main" to refer to the
6054
** main database file.
6055
** ^The third and fourth parameters to this routine
6056
** are passed directly through to the second and third parameters of
6057
** the xFileControl method.  ^The return value of the xFileControl
6058
** method becomes the return value of this routine.
6059
**
6060
** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
6061
** a pointer to the underlying [sqlite3_file] object to be written into
6062
** the space pointed to by the 4th parameter.  ^The SQLITE_FCNTL_FILE_POINTER
6063
** case is a short-circuit path which does not actually invoke the
6064
** underlying sqlite3_io_methods.xFileControl method.
6065
**
6066
** ^If the second parameter (zDbName) does not match the name of any
6067
** open database file, then SQLITE_ERROR is returned.  ^This error
6068
** code is not remembered and will not be recalled by [sqlite3_errcode()]
6069
** or [sqlite3_errmsg()].  The underlying xFileControl method might
6070
** also return SQLITE_ERROR.  There is no way to distinguish between
6071
** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6072
** xFileControl method.
6073
**
6074
** See also: [SQLITE_FCNTL_LOCKSTATE]
6075
*/
6076
SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6077

    
6078
/*
6079
** CAPI3REF: Testing Interface
6080
**
6081
** ^The sqlite3_test_control() interface is used to read out internal
6082
** state of SQLite and to inject faults into SQLite for testing
6083
** purposes.  ^The first parameter is an operation code that determines
6084
** the number, meaning, and operation of all subsequent parameters.
6085
**
6086
** This interface is not for use by applications.  It exists solely
6087
** for verifying the correct operation of the SQLite library.  Depending
6088
** on how the SQLite library is compiled, this interface might not exist.
6089
**
6090
** The details of the operation codes, their meanings, the parameters
6091
** they take, and what they do are all subject to change without notice.
6092
** Unlike most of the SQLite API, this function is not guaranteed to
6093
** operate consistently from one release to the next.
6094
*/
6095
SQLITE_API int sqlite3_test_control(int op, ...);
6096

    
6097
/*
6098
** CAPI3REF: Testing Interface Operation Codes
6099
**
6100
** These constants are the valid operation code parameters used
6101
** as the first argument to [sqlite3_test_control()].
6102
**
6103
** These parameters and their meanings are subject to change
6104
** without notice.  These values are for testing purposes only.
6105
** Applications should not use any of these parameters or the
6106
** [sqlite3_test_control()] interface.
6107
*/
6108
#define SQLITE_TESTCTRL_FIRST                    5
6109
#define SQLITE_TESTCTRL_PRNG_SAVE                5
6110
#define SQLITE_TESTCTRL_PRNG_RESTORE             6
6111
#define SQLITE_TESTCTRL_PRNG_RESET               7
6112
#define SQLITE_TESTCTRL_BITVEC_TEST              8
6113
#define SQLITE_TESTCTRL_FAULT_INSTALL            9
6114
#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
6115
#define SQLITE_TESTCTRL_PENDING_BYTE            11
6116
#define SQLITE_TESTCTRL_ASSERT                  12
6117
#define SQLITE_TESTCTRL_ALWAYS                  13
6118
#define SQLITE_TESTCTRL_RESERVE                 14
6119
#define SQLITE_TESTCTRL_OPTIMIZATIONS           15
6120
#define SQLITE_TESTCTRL_ISKEYWORD               16
6121
#define SQLITE_TESTCTRL_SCRATCHMALLOC           17
6122
#define SQLITE_TESTCTRL_LOCALTIME_FAULT         18
6123
#define SQLITE_TESTCTRL_EXPLAIN_STMT            19
6124
#define SQLITE_TESTCTRL_NEVER_CORRUPT           20
6125
#define SQLITE_TESTCTRL_LAST                    20
6126

    
6127
/*
6128
** CAPI3REF: SQLite Runtime Status
6129
**
6130
** ^This interface is used to retrieve runtime status information
6131
** about the performance of SQLite, and optionally to reset various
6132
** highwater marks.  ^The first argument is an integer code for
6133
** the specific parameter to measure.  ^(Recognized integer codes
6134
** are of the form [status parameters | SQLITE_STATUS_...].)^
6135
** ^The current value of the parameter is returned into *pCurrent.
6136
** ^The highest recorded value is returned in *pHighwater.  ^If the
6137
** resetFlag is true, then the highest record value is reset after
6138
** *pHighwater is written.  ^(Some parameters do not record the highest
6139
** value.  For those parameters
6140
** nothing is written into *pHighwater and the resetFlag is ignored.)^
6141
** ^(Other parameters record only the highwater mark and not the current
6142
** value.  For these latter parameters nothing is written into *pCurrent.)^
6143
**
6144
** ^The sqlite3_status() routine returns SQLITE_OK on success and a
6145
** non-zero [error code] on failure.
6146
**
6147
** This routine is threadsafe but is not atomic.  This routine can be
6148
** called while other threads are running the same or different SQLite
6149
** interfaces.  However the values returned in *pCurrent and
6150
** *pHighwater reflect the status of SQLite at different points in time
6151
** and it is possible that another thread might change the parameter
6152
** in between the times when *pCurrent and *pHighwater are written.
6153
**
6154
** See also: [sqlite3_db_status()]
6155
*/
6156
SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6157

    
6158

    
6159
/*
6160
** CAPI3REF: Status Parameters
6161
** KEYWORDS: {status parameters}
6162
**
6163
** These integer constants designate various run-time status parameters
6164
** that can be returned by [sqlite3_status()].
6165
**
6166
** <dl>
6167
** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
6168
** <dd>This parameter is the current amount of memory checked out
6169
** using [sqlite3_malloc()], either directly or indirectly.  The
6170
** figure includes calls made to [sqlite3_malloc()] by the application
6171
** and internal memory usage by the SQLite library.  Scratch memory
6172
** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6173
** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6174
** this parameter.  The amount returned is the sum of the allocation
6175
** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
6176
**
6177
** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
6178
** <dd>This parameter records the largest memory allocation request
6179
** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6180
** internal equivalents).  Only the value returned in the
6181
** *pHighwater parameter to [sqlite3_status()] is of interest.  
6182
** The value written into the *pCurrent parameter is undefined.</dd>)^
6183
**
6184
** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
6185
** <dd>This parameter records the number of separate memory allocations
6186
** currently checked out.</dd>)^
6187
**
6188
** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
6189
** <dd>This parameter returns the number of pages used out of the
6190
** [pagecache memory allocator] that was configured using 
6191
** [SQLITE_CONFIG_PAGECACHE].  The
6192
** value returned is in pages, not in bytes.</dd>)^
6193
**
6194
** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 
6195
** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
6196
** <dd>This parameter returns the number of bytes of page cache
6197
** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
6198
** buffer and where forced to overflow to [sqlite3_malloc()].  The
6199
** returned value includes allocations that overflowed because they
6200
** where too large (they were larger than the "sz" parameter to
6201
** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6202
** no space was left in the page cache.</dd>)^
6203
**
6204
** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
6205
** <dd>This parameter records the largest memory allocation request
6206
** handed to [pagecache memory allocator].  Only the value returned in the
6207
** *pHighwater parameter to [sqlite3_status()] is of interest.  
6208
** The value written into the *pCurrent parameter is undefined.</dd>)^
6209
**
6210
** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
6211
** <dd>This parameter returns the number of allocations used out of the
6212
** [scratch memory allocator] configured using
6213
** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
6214
** in bytes.  Since a single thread may only have one scratch allocation
6215
** outstanding at time, this parameter also reports the number of threads
6216
** using scratch memory at the same time.</dd>)^
6217
**
6218
** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
6219
** <dd>This parameter returns the number of bytes of scratch memory
6220
** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6221
** buffer and where forced to overflow to [sqlite3_malloc()].  The values
6222
** returned include overflows because the requested allocation was too
6223
** larger (that is, because the requested allocation was larger than the
6224
** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6225
** slots were available.
6226
** </dd>)^
6227
**
6228
** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
6229
** <dd>This parameter records the largest memory allocation request
6230
** handed to [scratch memory allocator].  Only the value returned in the
6231
** *pHighwater parameter to [sqlite3_status()] is of interest.  
6232
** The value written into the *pCurrent parameter is undefined.</dd>)^
6233
**
6234
** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
6235
** <dd>This parameter records the deepest parser stack.  It is only
6236
** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6237
** </dl>
6238
**
6239
** New status parameters may be added from time to time.
6240
*/
6241
#define SQLITE_STATUS_MEMORY_USED          0
6242
#define SQLITE_STATUS_PAGECACHE_USED       1
6243
#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
6244
#define SQLITE_STATUS_SCRATCH_USED         3
6245
#define SQLITE_STATUS_SCRATCH_OVERFLOW     4
6246
#define SQLITE_STATUS_MALLOC_SIZE          5
6247
#define SQLITE_STATUS_PARSER_STACK         6
6248
#define SQLITE_STATUS_PAGECACHE_SIZE       7
6249
#define SQLITE_STATUS_SCRATCH_SIZE         8
6250
#define SQLITE_STATUS_MALLOC_COUNT         9
6251

    
6252
/*
6253
** CAPI3REF: Database Connection Status
6254
**
6255
** ^This interface is used to retrieve runtime status information 
6256
** about a single [database connection].  ^The first argument is the
6257
** database connection object to be interrogated.  ^The second argument
6258
** is an integer constant, taken from the set of
6259
** [SQLITE_DBSTATUS options], that
6260
** determines the parameter to interrogate.  The set of 
6261
** [SQLITE_DBSTATUS options] is likely
6262
** to grow in future releases of SQLite.
6263
**
6264
** ^The current value of the requested parameter is written into *pCur
6265
** and the highest instantaneous value is written into *pHiwtr.  ^If
6266
** the resetFlg is true, then the highest instantaneous value is
6267
** reset back down to the current value.
6268
**
6269
** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6270
** non-zero [error code] on failure.
6271
**
6272
** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6273
*/
6274
SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6275

    
6276
/*
6277
** CAPI3REF: Status Parameters for database connections
6278
** KEYWORDS: {SQLITE_DBSTATUS options}
6279
**
6280
** These constants are the available integer "verbs" that can be passed as
6281
** the second argument to the [sqlite3_db_status()] interface.
6282
**
6283
** New verbs may be added in future releases of SQLite. Existing verbs
6284
** might be discontinued. Applications should check the return code from
6285
** [sqlite3_db_status()] to make sure that the call worked.
6286
** The [sqlite3_db_status()] interface will return a non-zero error code
6287
** if a discontinued or unsupported verb is invoked.
6288
**
6289
** <dl>
6290
** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
6291
** <dd>This parameter returns the number of lookaside memory slots currently
6292
** checked out.</dd>)^
6293
**
6294
** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
6295
** <dd>This parameter returns the number malloc attempts that were 
6296
** satisfied using lookaside memory. Only the high-water value is meaningful;
6297
** the current value is always zero.)^
6298
**
6299
** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
6300
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
6301
** <dd>This parameter returns the number malloc attempts that might have
6302
** been satisfied using lookaside memory but failed due to the amount of
6303
** memory requested being larger than the lookaside slot size.
6304
** Only the high-water value is meaningful;
6305
** the current value is always zero.)^
6306
**
6307
** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
6308
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
6309
** <dd>This parameter returns the number malloc attempts that might have
6310
** been satisfied using lookaside memory but failed due to all lookaside
6311
** memory already being in use.
6312
** Only the high-water value is meaningful;
6313
** the current value is always zero.)^
6314
**
6315
** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
6316
** <dd>This parameter returns the approximate number of of bytes of heap
6317
** memory used by all pager caches associated with the database connection.)^
6318
** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
6319
**
6320
** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
6321
** <dd>This parameter returns the approximate number of of bytes of heap
6322
** memory used to store the schema for all databases associated
6323
** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 
6324
** ^The full amount of memory used by the schemas is reported, even if the
6325
** schema memory is shared with other database connections due to
6326
** [shared cache mode] being enabled.
6327
** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
6328
**
6329
** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
6330
** <dd>This parameter returns the approximate number of of bytes of heap
6331
** and lookaside memory used by all prepared statements associated with
6332
** the database connection.)^
6333
** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
6334
** </dd>
6335
**
6336
** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
6337
** <dd>This parameter returns the number of pager cache hits that have
6338
** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 
6339
** is always 0.
6340
** </dd>
6341
**
6342
** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
6343
** <dd>This parameter returns the number of pager cache misses that have
6344
** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 
6345
** is always 0.
6346
** </dd>
6347
**
6348
** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
6349
** <dd>This parameter returns the number of dirty cache entries that have
6350
** been written to disk. Specifically, the number of pages written to the
6351
** wal file in wal mode databases, or the number of pages written to the
6352
** database file in rollback mode databases. Any pages written as part of
6353
** transaction rollback or database recovery operations are not included.
6354
** If an IO or other error occurs while writing a page to disk, the effect
6355
** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
6356
** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
6357
** </dd>
6358
**
6359
** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
6360
** <dd>This parameter returns zero for the current value if and only if
6361
** all foreign key constraints (deferred or immediate) have been
6362
** resolved.)^  ^The highwater mark is always 0.
6363
** </dd>
6364
** </dl>
6365
*/
6366
#define SQLITE_DBSTATUS_LOOKASIDE_USED       0
6367
#define SQLITE_DBSTATUS_CACHE_USED           1
6368
#define SQLITE_DBSTATUS_SCHEMA_USED          2
6369
#define SQLITE_DBSTATUS_STMT_USED            3
6370
#define SQLITE_DBSTATUS_LOOKASIDE_HIT        4
6371
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5
6372
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
6373
#define SQLITE_DBSTATUS_CACHE_HIT            7
6374
#define SQLITE_DBSTATUS_CACHE_MISS           8
6375
#define SQLITE_DBSTATUS_CACHE_WRITE          9
6376
#define SQLITE_DBSTATUS_DEFERRED_FKS        10
6377
#define SQLITE_DBSTATUS_MAX                 10   /* Largest defined DBSTATUS */
6378

    
6379

    
6380
/*
6381
** CAPI3REF: Prepared Statement Status
6382
**
6383
** ^(Each prepared statement maintains various
6384
** [SQLITE_STMTSTATUS counters] that measure the number
6385
** of times it has performed specific operations.)^  These counters can
6386
** be used to monitor the performance characteristics of the prepared
6387
** statements.  For example, if the number of table steps greatly exceeds
6388
** the number of table searches or result rows, that would tend to indicate
6389
** that the prepared statement is using a full table scan rather than
6390
** an index.  
6391
**
6392
** ^(This interface is used to retrieve and reset counter values from
6393
** a [prepared statement].  The first argument is the prepared statement
6394
** object to be interrogated.  The second argument
6395
** is an integer code for a specific [SQLITE_STMTSTATUS counter]
6396
** to be interrogated.)^
6397
** ^The current value of the requested counter is returned.
6398
** ^If the resetFlg is true, then the counter is reset to zero after this
6399
** interface call returns.
6400
**
6401
** See also: [sqlite3_status()] and [sqlite3_db_status()].
6402
*/
6403
SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
6404

    
6405
/*
6406
** CAPI3REF: Status Parameters for prepared statements
6407
** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
6408
**
6409
** These preprocessor macros define integer codes that name counter
6410
** values associated with the [sqlite3_stmt_status()] interface.
6411
** The meanings of the various counters are as follows:
6412
**
6413
** <dl>
6414
** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
6415
** <dd>^This is the number of times that SQLite has stepped forward in
6416
** a table as part of a full table scan.  Large numbers for this counter
6417
** may indicate opportunities for performance improvement through 
6418
** careful use of indices.</dd>
6419
**
6420
** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
6421
** <dd>^This is the number of sort operations that have occurred.
6422
** A non-zero value in this counter may indicate an opportunity to
6423
** improvement performance through careful use of indices.</dd>
6424
**
6425
** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
6426
** <dd>^This is the number of rows inserted into transient indices that
6427
** were created automatically in order to help joins run faster.
6428
** A non-zero value in this counter may indicate an opportunity to
6429
** improvement performance by adding permanent indices that do not
6430
** need to be reinitialized each time the statement is run.</dd>
6431
**
6432
** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
6433
** <dd>^This is the number of virtual machine operations executed
6434
** by the prepared statement if that number is less than or equal
6435
** to 2147483647.  The number of virtual machine operations can be 
6436
** used as a proxy for the total work done by the prepared statement.
6437
** If the number of virtual machine operations exceeds 2147483647
6438
** then the value returned by this statement status code is undefined.
6439
** </dd>
6440
** </dl>
6441
*/
6442
#define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
6443
#define SQLITE_STMTSTATUS_SORT              2
6444
#define SQLITE_STMTSTATUS_AUTOINDEX         3
6445
#define SQLITE_STMTSTATUS_VM_STEP           4
6446

    
6447
/*
6448
** CAPI3REF: Custom Page Cache Object
6449
**
6450
** The sqlite3_pcache type is opaque.  It is implemented by
6451
** the pluggable module.  The SQLite core has no knowledge of
6452
** its size or internal structure and never deals with the
6453
** sqlite3_pcache object except by holding and passing pointers
6454
** to the object.
6455
**
6456
** See [sqlite3_pcache_methods2] for additional information.
6457
*/
6458
typedef struct sqlite3_pcache sqlite3_pcache;
6459

    
6460
/*
6461
** CAPI3REF: Custom Page Cache Object
6462
**
6463
** The sqlite3_pcache_page object represents a single page in the
6464
** page cache.  The page cache will allocate instances of this
6465
** object.  Various methods of the page cache use pointers to instances
6466
** of this object as parameters or as their return value.
6467
**
6468
** See [sqlite3_pcache_methods2] for additional information.
6469
*/
6470
typedef struct sqlite3_pcache_page sqlite3_pcache_page;
6471
struct sqlite3_pcache_page {
6472
  void *pBuf;        /* The content of the page */
6473
  void *pExtra;      /* Extra information associated with the page */
6474
};
6475

    
6476
/*
6477
** CAPI3REF: Application Defined Page Cache.
6478
** KEYWORDS: {page cache}
6479
**
6480
** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
6481
** register an alternative page cache implementation by passing in an 
6482
** instance of the sqlite3_pcache_methods2 structure.)^
6483
** In many applications, most of the heap memory allocated by 
6484
** SQLite is used for the page cache.
6485
** By implementing a 
6486
** custom page cache using this API, an application can better control
6487
** the amount of memory consumed by SQLite, the way in which 
6488
** that memory is allocated and released, and the policies used to 
6489
** determine exactly which parts of a database file are cached and for 
6490
** how long.
6491
**
6492
** The alternative page cache mechanism is an
6493
** extreme measure that is only needed by the most demanding applications.
6494
** The built-in page cache is recommended for most uses.
6495
**
6496
** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
6497
** internal buffer by SQLite within the call to [sqlite3_config].  Hence
6498
** the application may discard the parameter after the call to
6499
** [sqlite3_config()] returns.)^
6500
**
6501
** [[the xInit() page cache method]]
6502
** ^(The xInit() method is called once for each effective 
6503
** call to [sqlite3_initialize()])^
6504
** (usually only once during the lifetime of the process). ^(The xInit()
6505
** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
6506
** The intent of the xInit() method is to set up global data structures 
6507
** required by the custom page cache implementation. 
6508
** ^(If the xInit() method is NULL, then the 
6509
** built-in default page cache is used instead of the application defined
6510
** page cache.)^
6511
**
6512
** [[the xShutdown() page cache method]]
6513
** ^The xShutdown() method is called by [sqlite3_shutdown()].
6514
** It can be used to clean up 
6515
** any outstanding resources before process shutdown, if required.
6516
** ^The xShutdown() method may be NULL.
6517
**
6518
** ^SQLite automatically serializes calls to the xInit method,
6519
** so the xInit method need not be threadsafe.  ^The
6520
** xShutdown method is only called from [sqlite3_shutdown()] so it does
6521
** not need to be threadsafe either.  All other methods must be threadsafe
6522
** in multithreaded applications.
6523
**
6524
** ^SQLite will never invoke xInit() more than once without an intervening
6525
** call to xShutdown().
6526
**
6527
** [[the xCreate() page cache methods]]
6528
** ^SQLite invokes the xCreate() method to construct a new cache instance.
6529
** SQLite will typically create one cache instance for each open database file,
6530
** though this is not guaranteed. ^The
6531
** first parameter, szPage, is the size in bytes of the pages that must
6532
** be allocated by the cache.  ^szPage will always a power of two.  ^The
6533
** second parameter szExtra is a number of bytes of extra storage 
6534
** associated with each page cache entry.  ^The szExtra parameter will
6535
** a number less than 250.  SQLite will use the
6536
** extra szExtra bytes on each page to store metadata about the underlying
6537
** database page on disk.  The value passed into szExtra depends
6538
** on the SQLite version, the target platform, and how SQLite was compiled.
6539
** ^The third argument to xCreate(), bPurgeable, is true if the cache being
6540
** created will be used to cache database pages of a file stored on disk, or
6541
** false if it is used for an in-memory database. The cache implementation
6542
** does not have to do anything special based with the value of bPurgeable;
6543
** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
6544
** never invoke xUnpin() except to deliberately delete a page.
6545
** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
6546
** false will always have the "discard" flag set to true.  
6547
** ^Hence, a cache created with bPurgeable false will
6548
** never contain any unpinned pages.
6549
**
6550
** [[the xCachesize() page cache method]]
6551
** ^(The xCachesize() method may be called at any time by SQLite to set the
6552
** suggested maximum cache-size (number of pages stored by) the cache
6553
** instance passed as the first argument. This is the value configured using
6554
** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
6555
** parameter, the implementation is not required to do anything with this
6556
** value; it is advisory only.
6557
**
6558
** [[the xPagecount() page cache methods]]
6559
** The xPagecount() method must return the number of pages currently
6560
** stored in the cache, both pinned and unpinned.
6561
** 
6562
** [[the xFetch() page cache methods]]
6563
** The xFetch() method locates a page in the cache and returns a pointer to 
6564
** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
6565
** The pBuf element of the returned sqlite3_pcache_page object will be a
6566
** pointer to a buffer of szPage bytes used to store the content of a 
6567
** single database page.  The pExtra element of sqlite3_pcache_page will be
6568
** a pointer to the szExtra bytes of extra storage that SQLite has requested
6569
** for each entry in the page cache.
6570
**
6571
** The page to be fetched is determined by the key. ^The minimum key value
6572
** is 1.  After it has been retrieved using xFetch, the page is considered
6573
** to be "pinned".
6574
**
6575
** If the requested page is already in the page cache, then the page cache
6576
** implementation must return a pointer to the page buffer with its content
6577
** intact.  If the requested page is not already in the cache, then the
6578
** cache implementation should use the value of the createFlag
6579
** parameter to help it determined what action to take:
6580
**
6581
** <table border=1 width=85% align=center>
6582
** <tr><th> createFlag <th> Behavior when page is not already in cache
6583
** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
6584
** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
6585
**                 Otherwise return NULL.
6586
** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
6587
**                 NULL if allocating a new page is effectively impossible.
6588
** </table>
6589
**
6590
** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
6591
** will only use a createFlag of 2 after a prior call with a createFlag of 1
6592
** failed.)^  In between the to xFetch() calls, SQLite may
6593
** attempt to unpin one or more cache pages by spilling the content of
6594
** pinned pages to disk and synching the operating system disk cache.
6595
**
6596
** [[the xUnpin() page cache method]]
6597
** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
6598
** as its second argument.  If the third parameter, discard, is non-zero,
6599
** then the page must be evicted from the cache.
6600
** ^If the discard parameter is
6601
** zero, then the page may be discarded or retained at the discretion of
6602
** page cache implementation. ^The page cache implementation
6603
** may choose to evict unpinned pages at any time.
6604
**
6605
** The cache must not perform any reference counting. A single 
6606
** call to xUnpin() unpins the page regardless of the number of prior calls 
6607
** to xFetch().
6608
**
6609
** [[the xRekey() page cache methods]]
6610
** The xRekey() method is used to change the key value associated with the
6611
** page passed as the second argument. If the cache
6612
** previously contains an entry associated with newKey, it must be
6613
** discarded. ^Any prior cache entry associated with newKey is guaranteed not
6614
** to be pinned.
6615
**
6616
** When SQLite calls the xTruncate() method, the cache must discard all
6617
** existing cache entries with page numbers (keys) greater than or equal
6618
** to the value of the iLimit parameter passed to xTruncate(). If any
6619
** of these pages are pinned, they are implicitly unpinned, meaning that
6620
** they can be safely discarded.
6621
**
6622
** [[the xDestroy() page cache method]]
6623
** ^The xDestroy() method is used to delete a cache allocated by xCreate().
6624
** All resources associated with the specified cache should be freed. ^After
6625
** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
6626
** handle invalid, and will not use it with any other sqlite3_pcache_methods2
6627
** functions.
6628
**
6629
** [[the xShrink() page cache method]]
6630
** ^SQLite invokes the xShrink() method when it wants the page cache to
6631
** free up as much of heap memory as possible.  The page cache implementation
6632
** is not obligated to free any memory, but well-behaved implementations should
6633
** do their best.
6634
*/
6635
typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
6636
struct sqlite3_pcache_methods2 {
6637
  int iVersion;
6638
  void *pArg;
6639
  int (*xInit)(void*);
6640
  void (*xShutdown)(void*);
6641
  sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
6642
  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6643
  int (*xPagecount)(sqlite3_pcache*);
6644
  sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6645
  void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
6646
  void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 
6647
      unsigned oldKey, unsigned newKey);
6648
  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6649
  void (*xDestroy)(sqlite3_pcache*);
6650
  void (*xShrink)(sqlite3_pcache*);
6651
};
6652

    
6653
/*
6654
** This is the obsolete pcache_methods object that has now been replaced
6655
** by sqlite3_pcache_methods2.  This object is not used by SQLite.  It is
6656
** retained in the header file for backwards compatibility only.
6657
*/
6658
typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
6659
struct sqlite3_pcache_methods {
6660
  void *pArg;
6661
  int (*xInit)(void*);
6662
  void (*xShutdown)(void*);
6663
  sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
6664
  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6665
  int (*xPagecount)(sqlite3_pcache*);
6666
  void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6667
  void (*xUnpin)(sqlite3_pcache*, void*, int discard);
6668
  void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
6669
  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6670
  void (*xDestroy)(sqlite3_pcache*);
6671
};
6672

    
6673

    
6674
/*
6675
** CAPI3REF: Online Backup Object
6676
**
6677
** The sqlite3_backup object records state information about an ongoing
6678
** online backup operation.  ^The sqlite3_backup object is created by
6679
** a call to [sqlite3_backup_init()] and is destroyed by a call to
6680
** [sqlite3_backup_finish()].
6681
**
6682
** See Also: [Using the SQLite Online Backup API]
6683
*/
6684
typedef struct sqlite3_backup sqlite3_backup;
6685

    
6686
/*
6687
** CAPI3REF: Online Backup API.
6688
**
6689
** The backup API copies the content of one database into another.
6690
** It is useful either for creating backups of databases or
6691
** for copying in-memory databases to or from persistent files. 
6692
**
6693
** See Also: [Using the SQLite Online Backup API]
6694
**
6695
** ^SQLite holds a write transaction open on the destination database file
6696
** for the duration of the backup operation.
6697
** ^The source database is read-locked only while it is being read;
6698
** it is not locked continuously for the entire backup operation.
6699
** ^Thus, the backup may be performed on a live source database without
6700
** preventing other database connections from
6701
** reading or writing to the source database while the backup is underway.
6702
** 
6703
** ^(To perform a backup operation: 
6704
**   <ol>
6705
**     <li><b>sqlite3_backup_init()</b> is called once to initialize the
6706
**         backup, 
6707
**     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 
6708
**         the data between the two databases, and finally
6709
**     <li><b>sqlite3_backup_finish()</b> is called to release all resources 
6710
**         associated with the backup operation. 
6711
**   </ol>)^
6712
** There should be exactly one call to sqlite3_backup_finish() for each
6713
** successful call to sqlite3_backup_init().
6714
**
6715
** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
6716
**
6717
** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 
6718
** [database connection] associated with the destination database 
6719
** and the database name, respectively.
6720
** ^The database name is "main" for the main database, "temp" for the
6721
** temporary database, or the name specified after the AS keyword in
6722
** an [ATTACH] statement for an attached database.
6723
** ^The S and M arguments passed to 
6724
** sqlite3_backup_init(D,N,S,M) identify the [database connection]
6725
** and database name of the source database, respectively.
6726
** ^The source and destination [database connections] (parameters S and D)
6727
** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
6728
** an error.
6729
**
6730
** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
6731
** returned and an error code and error message are stored in the
6732
** destination [database connection] D.
6733
** ^The error code and message for the failed call to sqlite3_backup_init()
6734
** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
6735
** [sqlite3_errmsg16()] functions.
6736
** ^A successful call to sqlite3_backup_init() returns a pointer to an
6737
** [sqlite3_backup] object.
6738
** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
6739
** sqlite3_backup_finish() functions to perform the specified backup 
6740
** operation.
6741
**
6742
** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
6743
**
6744
** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 
6745
** the source and destination databases specified by [sqlite3_backup] object B.
6746
** ^If N is negative, all remaining source pages are copied. 
6747
** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
6748
** are still more pages to be copied, then the function returns [SQLITE_OK].
6749
** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
6750
** from source to destination, then it returns [SQLITE_DONE].
6751
** ^If an error occurs while running sqlite3_backup_step(B,N),
6752
** then an [error code] is returned. ^As well as [SQLITE_OK] and
6753
** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
6754
** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
6755
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
6756
**
6757
** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
6758
** <ol>
6759
** <li> the destination database was opened read-only, or
6760
** <li> the destination database is using write-ahead-log journaling
6761
** and the destination and source page sizes differ, or
6762
** <li> the destination database is an in-memory database and the
6763
** destination and source page sizes differ.
6764
** </ol>)^
6765
**
6766
** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
6767
** the [sqlite3_busy_handler | busy-handler function]
6768
** is invoked (if one is specified). ^If the 
6769
** busy-handler returns non-zero before the lock is available, then 
6770
** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
6771
** sqlite3_backup_step() can be retried later. ^If the source
6772
** [database connection]
6773
** is being used to write to the source database when sqlite3_backup_step()
6774
** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
6775
** case the call to sqlite3_backup_step() can be retried later on. ^(If
6776
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
6777
** [SQLITE_READONLY] is returned, then 
6778
** there is no point in retrying the call to sqlite3_backup_step(). These 
6779
** errors are considered fatal.)^  The application must accept 
6780
** that the backup operation has failed and pass the backup operation handle 
6781
** to the sqlite3_backup_finish() to release associated resources.
6782
**
6783
** ^The first call to sqlite3_backup_step() obtains an exclusive lock
6784
** on the destination file. ^The exclusive lock is not released until either 
6785
** sqlite3_backup_finish() is called or the backup operation is complete 
6786
** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
6787
** sqlite3_backup_step() obtains a [shared lock] on the source database that
6788
** lasts for the duration of the sqlite3_backup_step() call.
6789
** ^Because the source database is not locked between calls to
6790
** sqlite3_backup_step(), the source database may be modified mid-way
6791
** through the backup process.  ^If the source database is modified by an
6792
** external process or via a database connection other than the one being
6793
** used by the backup operation, then the backup will be automatically
6794
** restarted by the next call to sqlite3_backup_step(). ^If the source 
6795
** database is modified by the using the same database connection as is used
6796
** by the backup operation, then the backup database is automatically
6797
** updated at the same time.
6798
**
6799
** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
6800
**
6801
** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 
6802
** application wishes to abandon the backup operation, the application
6803
** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
6804
** ^The sqlite3_backup_finish() interfaces releases all
6805
** resources associated with the [sqlite3_backup] object. 
6806
** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
6807
** active write-transaction on the destination database is rolled back.
6808
** The [sqlite3_backup] object is invalid
6809
** and may not be used following a call to sqlite3_backup_finish().
6810
**
6811
** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
6812
** sqlite3_backup_step() errors occurred, regardless or whether or not
6813
** sqlite3_backup_step() completed.
6814
** ^If an out-of-memory condition or IO error occurred during any prior
6815
** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
6816
** sqlite3_backup_finish() returns the corresponding [error code].
6817
**
6818
** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
6819
** is not a permanent error and does not affect the return value of
6820
** sqlite3_backup_finish().
6821
**
6822
** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
6823
** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
6824
**
6825
** ^Each call to sqlite3_backup_step() sets two values inside
6826
** the [sqlite3_backup] object: the number of pages still to be backed
6827
** up and the total number of pages in the source database file.
6828
** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
6829
** retrieve these two values, respectively.
6830
**
6831
** ^The values returned by these functions are only updated by
6832
** sqlite3_backup_step(). ^If the source database is modified during a backup
6833
** operation, then the values are not updated to account for any extra
6834
** pages that need to be updated or the size of the source database file
6835
** changing.
6836
**
6837
** <b>Concurrent Usage of Database Handles</b>
6838
**
6839
** ^The source [database connection] may be used by the application for other
6840
** purposes while a backup operation is underway or being initialized.
6841
** ^If SQLite is compiled and configured to support threadsafe database
6842
** connections, then the source database connection may be used concurrently
6843
** from within other threads.
6844
**
6845
** However, the application must guarantee that the destination 
6846
** [database connection] is not passed to any other API (by any thread) after 
6847
** sqlite3_backup_init() is called and before the corresponding call to
6848
** sqlite3_backup_finish().  SQLite does not currently check to see
6849
** if the application incorrectly accesses the destination [database connection]
6850
** and so no error code is reported, but the operations may malfunction
6851
** nevertheless.  Use of the destination database connection while a
6852
** backup is in progress might also also cause a mutex deadlock.
6853
**
6854
** If running in [shared cache mode], the application must
6855
** guarantee that the shared cache used by the destination database
6856
** is not accessed while the backup is running. In practice this means
6857
** that the application must guarantee that the disk file being 
6858
** backed up to is not accessed by any connection within the process,
6859
** not just the specific connection that was passed to sqlite3_backup_init().
6860
**
6861
** The [sqlite3_backup] object itself is partially threadsafe. Multiple 
6862
** threads may safely make multiple concurrent calls to sqlite3_backup_step().
6863
** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
6864
** APIs are not strictly speaking threadsafe. If they are invoked at the
6865
** same time as another thread is invoking sqlite3_backup_step() it is
6866
** possible that they return invalid values.
6867
*/
6868
SQLITE_API sqlite3_backup *sqlite3_backup_init(
6869
  sqlite3 *pDest,                        /* Destination database handle */
6870
  const char *zDestName,                 /* Destination database name */
6871
  sqlite3 *pSource,                      /* Source database handle */
6872
  const char *zSourceName                /* Source database name */
6873
);
6874
SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
6875
SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
6876
SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
6877
SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
6878

    
6879
/*
6880
** CAPI3REF: Unlock Notification
6881
**
6882
** ^When running in shared-cache mode, a database operation may fail with
6883
** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
6884
** individual tables within the shared-cache cannot be obtained. See
6885
** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 
6886
** ^This API may be used to register a callback that SQLite will invoke 
6887
** when the connection currently holding the required lock relinquishes it.
6888
** ^This API is only available if the library was compiled with the
6889
** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
6890
**
6891
** See Also: [Using the SQLite Unlock Notification Feature].
6892
**
6893
** ^Shared-cache locks are released when a database connection concludes
6894
** its current transaction, either by committing it or rolling it back. 
6895
**
6896
** ^When a connection (known as the blocked connection) fails to obtain a
6897
** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
6898
** identity of the database connection (the blocking connection) that
6899
** has locked the required resource is stored internally. ^After an 
6900
** application receives an SQLITE_LOCKED error, it may call the
6901
** sqlite3_unlock_notify() method with the blocked connection handle as 
6902
** the first argument to register for a callback that will be invoked
6903
** when the blocking connections current transaction is concluded. ^The
6904
** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
6905
** call that concludes the blocking connections transaction.
6906
**
6907
** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
6908
** there is a chance that the blocking connection will have already
6909
** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
6910
** If this happens, then the specified callback is invoked immediately,
6911
** from within the call to sqlite3_unlock_notify().)^
6912
**
6913
** ^If the blocked connection is attempting to obtain a write-lock on a
6914
** shared-cache table, and more than one other connection currently holds
6915
** a read-lock on the same table, then SQLite arbitrarily selects one of 
6916
** the other connections to use as the blocking connection.
6917
**
6918
** ^(There may be at most one unlock-notify callback registered by a 
6919
** blocked connection. If sqlite3_unlock_notify() is called when the
6920
** blocked connection already has a registered unlock-notify callback,
6921
** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
6922
** called with a NULL pointer as its second argument, then any existing
6923
** unlock-notify callback is canceled. ^The blocked connections 
6924
** unlock-notify callback may also be canceled by closing the blocked
6925
** connection using [sqlite3_close()].
6926
**
6927
** The unlock-notify callback is not reentrant. If an application invokes
6928
** any sqlite3_xxx API functions from within an unlock-notify callback, a
6929
** crash or deadlock may be the result.
6930
**
6931
** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
6932
** returns SQLITE_OK.
6933
**
6934
** <b>Callback Invocation Details</b>
6935
**
6936
** When an unlock-notify callback is registered, the application provides a 
6937
** single void* pointer that is passed to the callback when it is invoked.
6938
** However, the signature of the callback function allows SQLite to pass
6939
** it an array of void* context pointers. The first argument passed to
6940
** an unlock-notify callback is a pointer to an array of void* pointers,
6941
** and the second is the number of entries in the array.
6942
**
6943
** When a blocking connections transaction is concluded, there may be
6944
** more than one blocked connection that has registered for an unlock-notify
6945
** callback. ^If two or more such blocked connections have specified the
6946
** same callback function, then instead of invoking the callback function
6947
** multiple times, it is invoked once with the set of void* context pointers
6948
** specified by the blocked connections bundled together into an array.
6949
** This gives the application an opportunity to prioritize any actions 
6950
** related to the set of unblocked database connections.
6951
**
6952
** <b>Deadlock Detection</b>
6953
**
6954
** Assuming that after registering for an unlock-notify callback a 
6955
** database waits for the callback to be issued before taking any further
6956
** action (a reasonable assumption), then using this API may cause the
6957
** application to deadlock. For example, if connection X is waiting for
6958
** connection Y's transaction to be concluded, and similarly connection
6959
** Y is waiting on connection X's transaction, then neither connection
6960
** will proceed and the system may remain deadlocked indefinitely.
6961
**
6962
** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
6963
** detection. ^If a given call to sqlite3_unlock_notify() would put the
6964
** system in a deadlocked state, then SQLITE_LOCKED is returned and no
6965
** unlock-notify callback is registered. The system is said to be in
6966
** a deadlocked state if connection A has registered for an unlock-notify
6967
** callback on the conclusion of connection B's transaction, and connection
6968
** B has itself registered for an unlock-notify callback when connection
6969
** A's transaction is concluded. ^Indirect deadlock is also detected, so
6970
** the system is also considered to be deadlocked if connection B has
6971
** registered for an unlock-notify callback on the conclusion of connection
6972
** C's transaction, where connection C is waiting on connection A. ^Any
6973
** number of levels of indirection are allowed.
6974
**
6975
** <b>The "DROP TABLE" Exception</b>
6976
**
6977
** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 
6978
** always appropriate to call sqlite3_unlock_notify(). There is however,
6979
** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
6980
** SQLite checks if there are any currently executing SELECT statements
6981
** that belong to the same connection. If there are, SQLITE_LOCKED is
6982
** returned. In this case there is no "blocking connection", so invoking
6983
** sqlite3_unlock_notify() results in the unlock-notify callback being
6984
** invoked immediately. If the application then re-attempts the "DROP TABLE"
6985
** or "DROP INDEX" query, an infinite loop might be the result.
6986
**
6987
** One way around this problem is to check the extended error code returned
6988
** by an sqlite3_step() call. ^(If there is a blocking connection, then the
6989
** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
6990
** the special "DROP TABLE/INDEX" case, the extended error code is just 
6991
** SQLITE_LOCKED.)^
6992
*/
6993
SQLITE_API int sqlite3_unlock_notify(
6994
  sqlite3 *pBlocked,                          /* Waiting connection */
6995
  void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
6996
  void *pNotifyArg                            /* Argument to pass to xNotify */
6997
);
6998

    
6999

    
7000
/*
7001
** CAPI3REF: String Comparison
7002
**
7003
** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
7004
** and extensions to compare the contents of two buffers containing UTF-8
7005
** strings in a case-independent fashion, using the same definition of "case
7006
** independence" that SQLite uses internally when comparing identifiers.
7007
*/
7008
SQLITE_API int sqlite3_stricmp(const char *, const char *);
7009
SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
7010

    
7011
/*
7012
** CAPI3REF: String Globbing
7013
*
7014
** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches
7015
** the glob pattern P, and it returns non-zero if string X does not match
7016
** the glob pattern P.  ^The definition of glob pattern matching used in
7017
** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
7018
** SQL dialect used by SQLite.  ^The sqlite3_strglob(P,X) function is case
7019
** sensitive.
7020
**
7021
** Note that this routine returns zero on a match and non-zero if the strings
7022
** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7023
*/
7024
SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
7025

    
7026
/*
7027
** CAPI3REF: Error Logging Interface
7028
**
7029
** ^The [sqlite3_log()] interface writes a message into the [error log]
7030
** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
7031
** ^If logging is enabled, the zFormat string and subsequent arguments are
7032
** used with [sqlite3_snprintf()] to generate the final output string.
7033
**
7034
** The sqlite3_log() interface is intended for use by extensions such as
7035
** virtual tables, collating functions, and SQL functions.  While there is
7036
** nothing to prevent an application from calling sqlite3_log(), doing so
7037
** is considered bad form.
7038
**
7039
** The zFormat string must not be NULL.
7040
**
7041
** To avoid deadlocks and other threading problems, the sqlite3_log() routine
7042
** will not use dynamically allocated memory.  The log message is stored in
7043
** a fixed-length buffer on the stack.  If the log message is longer than
7044
** a few hundred characters, it will be truncated to the length of the
7045
** buffer.
7046
*/
7047
SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
7048

    
7049
/*
7050
** CAPI3REF: Write-Ahead Log Commit Hook
7051
**
7052
** ^The [sqlite3_wal_hook()] function is used to register a callback that
7053
** will be invoked each time a database connection commits data to a
7054
** [write-ahead log] (i.e. whenever a transaction is committed in
7055
** [journal_mode | journal_mode=WAL mode]). 
7056
**
7057
** ^The callback is invoked by SQLite after the commit has taken place and 
7058
** the associated write-lock on the database released, so the implementation 
7059
** may read, write or [checkpoint] the database as required.
7060
**
7061
** ^The first parameter passed to the callback function when it is invoked
7062
** is a copy of the third parameter passed to sqlite3_wal_hook() when
7063
** registering the callback. ^The second is a copy of the database handle.
7064
** ^The third parameter is the name of the database that was written to -
7065
** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
7066
** is the number of pages currently in the write-ahead log file,
7067
** including those that were just committed.
7068
**
7069
** The callback function should normally return [SQLITE_OK].  ^If an error
7070
** code is returned, that error will propagate back up through the
7071
** SQLite code base to cause the statement that provoked the callback
7072
** to report an error, though the commit will have still occurred. If the
7073
** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
7074
** that does not correspond to any valid SQLite error code, the results
7075
** are undefined.
7076
**
7077
** A single database handle may have at most a single write-ahead log callback 
7078
** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
7079
** previously registered write-ahead log callback. ^Note that the
7080
** [sqlite3_wal_autocheckpoint()] interface and the
7081
** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
7082
** those overwrite any prior [sqlite3_wal_hook()] settings.
7083
*/
7084
SQLITE_API void *sqlite3_wal_hook(
7085
  sqlite3*, 
7086
  int(*)(void *,sqlite3*,const char*,int),
7087
  void*
7088
);
7089

    
7090
/*
7091
** CAPI3REF: Configure an auto-checkpoint
7092
**
7093
** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
7094
** [sqlite3_wal_hook()] that causes any database on [database connection] D
7095
** to automatically [checkpoint]
7096
** after committing a transaction if there are N or
7097
** more frames in the [write-ahead log] file.  ^Passing zero or 
7098
** a negative value as the nFrame parameter disables automatic
7099
** checkpoints entirely.
7100
**
7101
** ^The callback registered by this function replaces any existing callback
7102
** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
7103
** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
7104
** configured by this function.
7105
**
7106
** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
7107
** from SQL.
7108
**
7109
** ^Every new [database connection] defaults to having the auto-checkpoint
7110
** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
7111
** pages.  The use of this interface
7112
** is only necessary if the default setting is found to be suboptimal
7113
** for a particular application.
7114
*/
7115
SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
7116

    
7117
/*
7118
** CAPI3REF: Checkpoint a database
7119
**
7120
** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
7121
** on [database connection] D to be [checkpointed].  ^If X is NULL or an
7122
** empty string, then a checkpoint is run on all databases of
7123
** connection D.  ^If the database connection D is not in
7124
** [WAL | write-ahead log mode] then this interface is a harmless no-op.
7125
**
7126
** ^The [wal_checkpoint pragma] can be used to invoke this interface
7127
** from SQL.  ^The [sqlite3_wal_autocheckpoint()] interface and the
7128
** [wal_autocheckpoint pragma] can be used to cause this interface to be
7129
** run whenever the WAL reaches a certain size threshold.
7130
**
7131
** See also: [sqlite3_wal_checkpoint_v2()]
7132
*/
7133
SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
7134

    
7135
/*
7136
** CAPI3REF: Checkpoint a database
7137
**
7138
** Run a checkpoint operation on WAL database zDb attached to database 
7139
** handle db. The specific operation is determined by the value of the 
7140
** eMode parameter:
7141
**
7142
** <dl>
7143
** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
7144
**   Checkpoint as many frames as possible without waiting for any database 
7145
**   readers or writers to finish. Sync the db file if all frames in the log
7146
**   are checkpointed. This mode is the same as calling 
7147
**   sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
7148
**
7149
** <dt>SQLITE_CHECKPOINT_FULL<dd>
7150
**   This mode blocks (calls the busy-handler callback) until there is no
7151
**   database writer and all readers are reading from the most recent database
7152
**   snapshot. It then checkpoints all frames in the log file and syncs the
7153
**   database file. This call blocks database writers while it is running,
7154
**   but not database readers.
7155
**
7156
** <dt>SQLITE_CHECKPOINT_RESTART<dd>
7157
**   This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 
7158
**   checkpointing the log file it blocks (calls the busy-handler callback)
7159
**   until all readers are reading from the database file only. This ensures 
7160
**   that the next client to write to the database file restarts the log file 
7161
**   from the beginning. This call blocks database writers while it is running,
7162
**   but not database readers.
7163
** </dl>
7164
**
7165
** If pnLog is not NULL, then *pnLog is set to the total number of frames in
7166
** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
7167
** the total number of checkpointed frames (including any that were already
7168
** checkpointed when this function is called). *pnLog and *pnCkpt may be
7169
** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
7170
** If no values are available because of an error, they are both set to -1
7171
** before returning to communicate this to the caller.
7172
**
7173
** All calls obtain an exclusive "checkpoint" lock on the database file. If
7174
** any other process is running a checkpoint operation at the same time, the 
7175
** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 
7176
** busy-handler configured, it will not be invoked in this case.
7177
**
7178
** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 
7179
** "writer" lock on the database file. If the writer lock cannot be obtained
7180
** immediately, and a busy-handler is configured, it is invoked and the writer
7181
** lock retried until either the busy-handler returns 0 or the lock is
7182
** successfully obtained. The busy-handler is also invoked while waiting for
7183
** database readers as described above. If the busy-handler returns 0 before
7184
** the writer lock is obtained or while waiting for database readers, the
7185
** checkpoint operation proceeds from that point in the same way as 
7186
** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 
7187
** without blocking any further. SQLITE_BUSY is returned in this case.
7188
**
7189
** If parameter zDb is NULL or points to a zero length string, then the
7190
** specified operation is attempted on all WAL databases. In this case the
7191
** values written to output parameters *pnLog and *pnCkpt are undefined. If 
7192
** an SQLITE_BUSY error is encountered when processing one or more of the 
7193
** attached WAL databases, the operation is still attempted on any remaining 
7194
** attached databases and SQLITE_BUSY is returned to the caller. If any other 
7195
** error occurs while processing an attached database, processing is abandoned 
7196
** and the error code returned to the caller immediately. If no error 
7197
** (SQLITE_BUSY or otherwise) is encountered while processing the attached 
7198
** databases, SQLITE_OK is returned.
7199
**
7200
** If database zDb is the name of an attached database that is not in WAL
7201
** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
7202
** zDb is not NULL (or a zero length string) and is not the name of any
7203
** attached database, SQLITE_ERROR is returned to the caller.
7204
*/
7205
SQLITE_API int sqlite3_wal_checkpoint_v2(
7206
  sqlite3 *db,                    /* Database handle */
7207
  const char *zDb,                /* Name of attached database (or NULL) */
7208
  int eMode,                      /* SQLITE_CHECKPOINT_* value */
7209
  int *pnLog,                     /* OUT: Size of WAL log in frames */
7210
  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
7211
);
7212

    
7213
/*
7214
** CAPI3REF: Checkpoint operation parameters
7215
**
7216
** These constants can be used as the 3rd parameter to
7217
** [sqlite3_wal_checkpoint_v2()].  See the [sqlite3_wal_checkpoint_v2()]
7218
** documentation for additional information about the meaning and use of
7219
** each of these values.
7220
*/
7221
#define SQLITE_CHECKPOINT_PASSIVE 0
7222
#define SQLITE_CHECKPOINT_FULL    1
7223
#define SQLITE_CHECKPOINT_RESTART 2
7224

    
7225
/*
7226
** CAPI3REF: Virtual Table Interface Configuration
7227
**
7228
** This function may be called by either the [xConnect] or [xCreate] method
7229
** of a [virtual table] implementation to configure
7230
** various facets of the virtual table interface.
7231
**
7232
** If this interface is invoked outside the context of an xConnect or
7233
** xCreate virtual table method then the behavior is undefined.
7234
**
7235
** At present, there is only one option that may be configured using
7236
** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options
7237
** may be added in the future.
7238
*/
7239
SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
7240

    
7241
/*
7242
** CAPI3REF: Virtual Table Configuration Options
7243
**
7244
** These macros define the various options to the
7245
** [sqlite3_vtab_config()] interface that [virtual table] implementations
7246
** can use to customize and optimize their behavior.
7247
**
7248
** <dl>
7249
** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
7250
** <dd>Calls of the form
7251
** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
7252
** where X is an integer.  If X is zero, then the [virtual table] whose
7253
** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
7254
** support constraints.  In this configuration (which is the default) if
7255
** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
7256
** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
7257
** specified as part of the users SQL statement, regardless of the actual
7258
** ON CONFLICT mode specified.
7259
**
7260
** If X is non-zero, then the virtual table implementation guarantees
7261
** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
7262
** any modifications to internal or persistent data structures have been made.
7263
** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 
7264
** is able to roll back a statement or database transaction, and abandon
7265
** or continue processing the current SQL statement as appropriate. 
7266
** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
7267
** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
7268
** had been ABORT.
7269
**
7270
** Virtual table implementations that are required to handle OR REPLACE
7271
** must do so within the [xUpdate] method. If a call to the 
7272
** [sqlite3_vtab_on_conflict()] function indicates that the current ON 
7273
** CONFLICT policy is REPLACE, the virtual table implementation should 
7274
** silently replace the appropriate rows within the xUpdate callback and
7275
** return SQLITE_OK. Or, if this is not possible, it may return
7276
** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 
7277
** constraint handling.
7278
** </dl>
7279
*/
7280
#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
7281

    
7282
/*
7283
** CAPI3REF: Determine The Virtual Table Conflict Policy
7284
**
7285
** This function may only be called from within a call to the [xUpdate] method
7286
** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
7287
** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
7288
** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
7289
** of the SQL statement that triggered the call to the [xUpdate] method of the
7290
** [virtual table].
7291
*/
7292
SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
7293

    
7294
/*
7295
** CAPI3REF: Conflict resolution modes
7296
**
7297
** These constants are returned by [sqlite3_vtab_on_conflict()] to
7298
** inform a [virtual table] implementation what the [ON CONFLICT] mode
7299
** is for the SQL statement being evaluated.
7300
**
7301
** Note that the [SQLITE_IGNORE] constant is also used as a potential
7302
** return value from the [sqlite3_set_authorizer()] callback and that
7303
** [SQLITE_ABORT] is also a [result code].
7304
*/
7305
#define SQLITE_ROLLBACK 1
7306
/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
7307
#define SQLITE_FAIL     3
7308
/* #define SQLITE_ABORT 4  // Also an error code */
7309
#define SQLITE_REPLACE  5
7310

    
7311

    
7312

    
7313
/*
7314
** Undo the hack that converts floating point types to integer for
7315
** builds on processors without floating point support.
7316
*/
7317
#ifdef SQLITE_OMIT_FLOATING_POINT
7318
# undef double
7319
#endif
7320

    
7321
#ifdef __cplusplus
7322
}  /* End of the 'extern "C"' block */
7323
#endif
7324
#endif /* _SQLITE3_H_ */
7325

    
7326
/*
7327
** 2010 August 30
7328
**
7329
** The author disclaims copyright to this source code.  In place of
7330
** a legal notice, here is a blessing:
7331
**
7332
**    May you do good and not evil.
7333
**    May you find forgiveness for yourself and forgive others.
7334
**    May you share freely, never taking more than you give.
7335
**
7336
*************************************************************************
7337
*/
7338

    
7339
#ifndef _SQLITE3RTREE_H_
7340
#define _SQLITE3RTREE_H_
7341

    
7342

    
7343
#ifdef __cplusplus
7344
extern "C" {
7345
#endif
7346

    
7347
typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
7348

    
7349
/*
7350
** Register a geometry callback named zGeom that can be used as part of an
7351
** R-Tree geometry query as follows:
7352
**
7353
**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
7354
*/
7355
SQLITE_API int sqlite3_rtree_geometry_callback(
7356
  sqlite3 *db,
7357
  const char *zGeom,
7358
#ifdef SQLITE_RTREE_INT_ONLY
7359
  int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes),
7360
#else
7361
  int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes),
7362
#endif
7363
  void *pContext
7364
);
7365

    
7366

    
7367
/*
7368
** A pointer to a structure of the following type is passed as the first
7369
** argument to callbacks registered using rtree_geometry_callback().
7370
*/
7371
struct sqlite3_rtree_geometry {
7372
  void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
7373
  int nParam;                     /* Size of array aParam[] */
7374
  double *aParam;                 /* Parameters passed to SQL geom function */
7375
  void *pUser;                    /* Callback implementation user data */
7376
  void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
7377
};
7378

    
7379

    
7380
#ifdef __cplusplus
7381
}  /* end of the 'extern "C"' block */
7382
#endif
7383

    
7384
#endif  /* ifndef _SQLITE3RTREE_H_ */
7385