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Diffstat (limited to 'src/sqlite.h.in')
| -rw-r--r-- | src/sqlite.h.in | 10474 |
1 files changed, 10474 insertions, 0 deletions
diff --git a/src/sqlite.h.in b/src/sqlite.h.in new file mode 100644 index 0000000..0d3040a --- /dev/null +++ b/src/sqlite.h.in @@ -0,0 +1,10474 @@ +/* +** 2001-09-15 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** This header file defines the interface that the SQLite library +** presents to client programs. If a C-function, structure, datatype, +** or constant definition does not appear in this file, then it is +** not a published API of SQLite, is subject to change without +** notice, and should not be referenced by programs that use SQLite. +** +** Some of the definitions that are in this file are marked as +** "experimental". Experimental interfaces are normally new +** features recently added to SQLite. We do not anticipate changes +** to experimental interfaces but reserve the right to make minor changes +** if experience from use "in the wild" suggest such changes are prudent. +** +** The official C-language API documentation for SQLite is derived +** from comments in this file. This file is the authoritative source +** on how SQLite interfaces are supposed to operate. +** +** The name of this file under configuration management is "sqlite.h.in". +** The makefile makes some minor changes to this file (such as inserting +** the version number) and changes its name to "sqlite3.h" as +** part of the build process. +*/ +#ifndef SQLITE3_H +#define SQLITE3_H +#include <stdarg.h> /* Needed for the definition of va_list */ + +/* +** Make sure we can call this stuff from C++. +*/ +#ifdef __cplusplus +extern "C" { +#endif + + +/* +** Facilitate override of interface linkage and calling conventions. +** Be aware that these macros may not be used within this particular +** translation of the amalgamation and its associated header file. +** +** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the +** compiler that the target identifier should have external linkage. +** +** The SQLITE_CDECL macro is used to set the calling convention for +** public functions that accept a variable number of arguments. +** +** The SQLITE_APICALL macro is used to set the calling convention for +** public functions that accept a fixed number of arguments. +** +** The SQLITE_STDCALL macro is no longer used and is now deprecated. +** +** The SQLITE_CALLBACK macro is used to set the calling convention for +** function pointers. +** +** The SQLITE_SYSAPI macro is used to set the calling convention for +** functions provided by the operating system. +** +** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and +** SQLITE_SYSAPI macros are used only when building for environments +** that require non-default calling conventions. +*/ +#ifndef SQLITE_EXTERN +# define SQLITE_EXTERN extern +#endif +#ifndef SQLITE_API +# define SQLITE_API +#endif +#ifndef SQLITE_CDECL +# define SQLITE_CDECL +#endif +#ifndef SQLITE_APICALL +# define SQLITE_APICALL +#endif +#ifndef SQLITE_STDCALL +# define SQLITE_STDCALL SQLITE_APICALL +#endif +#ifndef SQLITE_CALLBACK +# define SQLITE_CALLBACK +#endif +#ifndef SQLITE_SYSAPI +# define SQLITE_SYSAPI +#endif + +/* +** These no-op macros are used in front of interfaces to mark those +** interfaces as either deprecated or experimental. New applications +** should not use deprecated interfaces - they are supported for backwards +** compatibility only. Application writers should be aware that +** experimental interfaces are subject to change in point releases. +** +** These macros used to resolve to various kinds of compiler magic that +** would generate warning messages when they were used. But that +** compiler magic ended up generating such a flurry of bug reports +** that we have taken it all out and gone back to using simple +** noop macros. +*/ +#define SQLITE_DEPRECATED +#define SQLITE_EXPERIMENTAL + +/* +** Ensure these symbols were not defined by some previous header file. +*/ +#ifdef SQLITE_VERSION +# undef SQLITE_VERSION +#endif +#ifdef SQLITE_VERSION_NUMBER +# undef SQLITE_VERSION_NUMBER +#endif + +/* +** CAPI3REF: Compile-Time Library Version Numbers +** +** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header +** evaluates to a string literal that is the SQLite version in the +** format "X.Y.Z" where X is the major version number (always 3 for +** SQLite3) and Y is the minor version number and Z is the release number.)^ +** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer +** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same +** numbers used in [SQLITE_VERSION].)^ +** The SQLITE_VERSION_NUMBER for any given release of SQLite will also +** be larger than the release from which it is derived. Either Y will +** be held constant and Z will be incremented or else Y will be incremented +** and Z will be reset to zero. +** +** Since [version 3.6.18] ([dateof:3.6.18]), +** SQLite source code has been stored in the +** <a href="http://www.fossil-scm.org/">Fossil configuration management +** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to +** a string which identifies a particular check-in of SQLite +** within its configuration management system. ^The SQLITE_SOURCE_ID +** string contains the date and time of the check-in (UTC) and a SHA1 +** or SHA3-256 hash of the entire source tree. If the source code has +** been edited in any way since it was last checked in, then the last +** four hexadecimal digits of the hash may be modified. +** +** See also: [sqlite3_libversion()], +** [sqlite3_libversion_number()], [sqlite3_sourceid()], +** [sqlite_version()] and [sqlite_source_id()]. +*/ +#define SQLITE_VERSION "--VERS--" +#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- +#define SQLITE_SOURCE_ID "--SOURCE-ID--" + +/* +** CAPI3REF: Run-Time Library Version Numbers +** KEYWORDS: sqlite3_version sqlite3_sourceid +** +** These interfaces provide the same information as the [SQLITE_VERSION], +** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros +** but are associated with the library instead of the header file. ^(Cautious +** programmers might include assert() statements in their application to +** verify that values returned by these interfaces match the macros in +** the header, and thus ensure that the application is +** compiled with matching library and header files. +** +** <blockquote><pre> +** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); +** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); +** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); +** </pre></blockquote>)^ +** +** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] +** macro. ^The sqlite3_libversion() function returns a pointer to the +** to the sqlite3_version[] string constant. The sqlite3_libversion() +** function is provided for use in DLLs since DLL users usually do not have +** direct access to string constants within the DLL. ^The +** sqlite3_libversion_number() function returns an integer equal to +** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns +** a pointer to a string constant whose value is the same as the +** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built +** using an edited copy of [the amalgamation], then the last four characters +** of the hash might be different from [SQLITE_SOURCE_ID].)^ +** +** See also: [sqlite_version()] and [sqlite_source_id()]. +*/ +SQLITE_EXTERN const char sqlite3_version[]; +const char *sqlite3_libversion(void); +const char *sqlite3_sourceid(void); +int sqlite3_libversion_number(void); + +/* +** CAPI3REF: Run-Time Library Compilation Options Diagnostics +** +** ^The sqlite3_compileoption_used() function returns 0 or 1 +** indicating whether the specified option was defined at +** compile time. ^The SQLITE_ prefix may be omitted from the +** option name passed to sqlite3_compileoption_used(). +** +** ^The sqlite3_compileoption_get() function allows iterating +** over the list of options that were defined at compile time by +** returning the N-th compile time option string. ^If N is out of range, +** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ +** prefix is omitted from any strings returned by +** sqlite3_compileoption_get(). +** +** ^Support for the diagnostic functions sqlite3_compileoption_used() +** and sqlite3_compileoption_get() may be omitted by specifying the +** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. +** +** See also: SQL functions [sqlite_compileoption_used()] and +** [sqlite_compileoption_get()] and the [compile_options pragma]. +*/ +#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS +int sqlite3_compileoption_used(const char *zOptName); +const char *sqlite3_compileoption_get(int N); +#else +# define sqlite3_compileoption_used(X) 0 +# define sqlite3_compileoption_get(X) ((void*)0) +#endif + +/* +** CAPI3REF: Test To See If The Library Is Threadsafe +** +** ^The sqlite3_threadsafe() function returns zero if and only if +** SQLite was compiled with mutexing code omitted due to the +** [SQLITE_THREADSAFE] compile-time option being set to 0. +** +** SQLite can be compiled with or without mutexes. When +** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes +** are enabled and SQLite is threadsafe. When the +** [SQLITE_THREADSAFE] macro is 0, +** the mutexes are omitted. Without the mutexes, it is not safe +** to use SQLite concurrently from more than one thread. +** +** Enabling mutexes incurs a measurable performance penalty. +** So if speed is of utmost importance, it makes sense to disable +** the mutexes. But for maximum safety, mutexes should be enabled. +** ^The default behavior is for mutexes to be enabled. +** +** This interface can be used by an application to make sure that the +** version of SQLite that it is linking against was compiled with +** the desired setting of the [SQLITE_THREADSAFE] macro. +** +** This interface only reports on the compile-time mutex setting +** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with +** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but +** can be fully or partially disabled using a call to [sqlite3_config()] +** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], +** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the +** sqlite3_threadsafe() function shows only the compile-time setting of +** thread safety, not any run-time changes to that setting made by +** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() +** is unchanged by calls to sqlite3_config().)^ +** +** See the [threading mode] documentation for additional information. +*/ +int sqlite3_threadsafe(void); + +/* +** CAPI3REF: Database Connection Handle +** KEYWORDS: {database connection} {database connections} +** +** Each open SQLite database is represented by a pointer to an instance of +** the opaque structure named "sqlite3". It is useful to think of an sqlite3 +** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and +** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] +** and [sqlite3_close_v2()] are its destructors. There are many other +** interfaces (such as +** [sqlite3_prepare_v2()], [sqlite3_create_function()], and +** [sqlite3_busy_timeout()] to name but three) that are methods on an +** sqlite3 object. +*/ +typedef struct sqlite3 sqlite3; + +/* +** CAPI3REF: 64-Bit Integer Types +** KEYWORDS: sqlite_int64 sqlite_uint64 +** +** Because there is no cross-platform way to specify 64-bit integer types +** SQLite includes typedefs for 64-bit signed and unsigned integers. +** +** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. +** The sqlite_int64 and sqlite_uint64 types are supported for backwards +** compatibility only. +** +** ^The sqlite3_int64 and sqlite_int64 types can store integer values +** between -9223372036854775808 and +9223372036854775807 inclusive. ^The +** sqlite3_uint64 and sqlite_uint64 types can store integer values +** between 0 and +18446744073709551615 inclusive. +*/ +#ifdef SQLITE_INT64_TYPE + typedef SQLITE_INT64_TYPE sqlite_int64; +# ifdef SQLITE_UINT64_TYPE + typedef SQLITE_UINT64_TYPE sqlite_uint64; +# else + typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; +# endif +#elif defined(_MSC_VER) || defined(__BORLANDC__) + typedef __int64 sqlite_int64; + typedef unsigned __int64 sqlite_uint64; +#else + typedef long long int sqlite_int64; + typedef unsigned long long int sqlite_uint64; +#endif +typedef sqlite_int64 sqlite3_int64; +typedef sqlite_uint64 sqlite3_uint64; + +/* +** If compiling for a processor that lacks floating point support, +** substitute integer for floating-point. +*/ +#ifdef SQLITE_OMIT_FLOATING_POINT +# define double sqlite3_int64 +#endif + +/* +** CAPI3REF: Closing A Database Connection +** DESTRUCTOR: sqlite3 +** +** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors +** for the [sqlite3] object. +** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if +** the [sqlite3] object is successfully destroyed and all associated +** resources are deallocated. +** +** Ideally, applications should [sqlite3_finalize | finalize] all +** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and +** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated +** with the [sqlite3] object prior to attempting to close the object. +** ^If the database connection is associated with unfinalized prepared +** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then +** sqlite3_close() will leave the database connection open and return +** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared +** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, +** it returns [SQLITE_OK] regardless, but instead of deallocating the database +** connection immediately, it marks the database connection as an unusable +** "zombie" and makes arrangements to automatically deallocate the database +** connection after all prepared statements are finalized, all BLOB handles +** are closed, and all backups have finished. The sqlite3_close_v2() interface +** is intended for use with host languages that are garbage collected, and +** where the order in which destructors are called is arbitrary. +** +** ^If an [sqlite3] object is destroyed while a transaction is open, +** the transaction is automatically rolled back. +** +** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] +** must be either a NULL +** pointer or an [sqlite3] object pointer obtained +** from [sqlite3_open()], [sqlite3_open16()], or +** [sqlite3_open_v2()], and not previously closed. +** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer +** argument is a harmless no-op. +*/ +int sqlite3_close(sqlite3*); +int sqlite3_close_v2(sqlite3*); + +/* +** The type for a callback function. +** This is legacy and deprecated. It is included for historical +** compatibility and is not documented. +*/ +typedef int (*sqlite3_callback)(void*,int,char**, char**); + +/* +** CAPI3REF: One-Step Query Execution Interface +** METHOD: sqlite3 +** +** The sqlite3_exec() interface is a convenience wrapper around +** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], +** that allows an application to run multiple statements of SQL +** without having to use a lot of C code. +** +** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, +** semicolon-separate SQL statements passed into its 2nd argument, +** in the context of the [database connection] passed in as its 1st +** argument. ^If the callback function of the 3rd argument to +** sqlite3_exec() is not NULL, then it is invoked for each result row +** coming out of the evaluated SQL statements. ^The 4th argument to +** sqlite3_exec() is relayed through to the 1st argument of each +** callback invocation. ^If the callback pointer to sqlite3_exec() +** is NULL, then no callback is ever invoked and result rows are +** ignored. +** +** ^If an error occurs while evaluating the SQL statements passed into +** sqlite3_exec(), then execution of the current statement stops and +** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() +** is not NULL then any error message is written into memory obtained +** from [sqlite3_malloc()] and passed back through the 5th parameter. +** To avoid memory leaks, the application should invoke [sqlite3_free()] +** on error message strings returned through the 5th parameter of +** sqlite3_exec() after the error message string is no longer needed. +** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors +** occur, then sqlite3_exec() sets the pointer in its 5th parameter to +** NULL before returning. +** +** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() +** routine returns SQLITE_ABORT without invoking the callback again and +** without running any subsequent SQL statements. +** +** ^The 2nd argument to the sqlite3_exec() callback function is the +** number of columns in the result. ^The 3rd argument to the sqlite3_exec() +** callback is an array of pointers to strings obtained as if from +** [sqlite3_column_text()], one for each column. ^If an element of a +** result row is NULL then the corresponding string pointer for the +** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the +** sqlite3_exec() callback is an array of pointers to strings where each +** entry represents the name of corresponding result column as obtained +** from [sqlite3_column_name()]. +** +** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer +** to an empty string, or a pointer that contains only whitespace and/or +** SQL comments, then no SQL statements are evaluated and the database +** is not changed. +** +** Restrictions: +** +** <ul> +** <li> The application must ensure that the 1st parameter to sqlite3_exec() +** is a valid and open [database connection]. +** <li> The application must not close the [database connection] specified by +** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. +** <li> The application must not modify the SQL statement text passed into +** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. +** </ul> +*/ +int sqlite3_exec( + sqlite3*, /* An open database */ + const char *sql, /* SQL to be evaluated */ + int (*callback)(void*,int,char**,char**), /* Callback function */ + void *, /* 1st argument to callback */ + char **errmsg /* Error msg written here */ +); + +/* +** CAPI3REF: Result Codes +** KEYWORDS: {result code definitions} +** +** Many SQLite functions return an integer result code from the set shown +** here in order to indicate success or failure. +** +** New error codes may be added in future versions of SQLite. +** +** See also: [extended result code definitions] +*/ +#define SQLITE_OK 0 /* Successful result */ +/* beginning-of-error-codes */ +#define SQLITE_ERROR 1 /* Generic error */ +#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ +#define SQLITE_PERM 3 /* Access permission denied */ +#define SQLITE_ABORT 4 /* Callback routine requested an abort */ +#define SQLITE_BUSY 5 /* The database file is locked */ +#define SQLITE_LOCKED 6 /* A table in the database is locked */ +#define SQLITE_NOMEM 7 /* A malloc() failed */ +#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ +#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ +#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ +#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ +#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ +#define SQLITE_FULL 13 /* Insertion failed because database is full */ +#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ +#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ +#define SQLITE_EMPTY 16 /* Internal use only */ +#define SQLITE_SCHEMA 17 /* The database schema changed */ +#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ +#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ +#define SQLITE_MISMATCH 20 /* Data type mismatch */ +#define SQLITE_MISUSE 21 /* Library used incorrectly */ +#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ +#define SQLITE_AUTH 23 /* Authorization denied */ +#define SQLITE_FORMAT 24 /* Not used */ +#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ +#define SQLITE_NOTADB 26 /* File opened that is not a database file */ +#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ +#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ +#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ +#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ +/* end-of-error-codes */ + +/* +** CAPI3REF: Extended Result Codes +** KEYWORDS: {extended result code definitions} +** +** In its default configuration, SQLite API routines return one of 30 integer +** [result codes]. However, experience has shown that many of +** these result codes are too coarse-grained. They do not provide as +** much information about problems as programmers might like. In an effort to +** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] +** and later) include +** support for additional result codes that provide more detailed information +** about errors. These [extended result codes] are enabled or disabled +** on a per database connection basis using the +** [sqlite3_extended_result_codes()] API. Or, the extended code for +** the most recent error can be obtained using +** [sqlite3_extended_errcode()]. +*/ +#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) +#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) +#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) +#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) +#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) +#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) +#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) +#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) +#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) +#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) +#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) +#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) +#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) +#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) +#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) +#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) +#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) +#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) +#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) +#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) +#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) +#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) +#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) +#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) +#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) +#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) +#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) +#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) +#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) +#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) +#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) +#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) +#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) +#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) +#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) +#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) +#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) +#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) +#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) +#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) +#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) +#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) +#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) +#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) +#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) +#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ +#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) +#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) +#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) +#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) +#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) +#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) +#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) +#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) +#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) +#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) +#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) +#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) +#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) +#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) +#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) +#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) +#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) +#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) +#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) +#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) +#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) +#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) +#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) +#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) +#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) +#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) +#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) +#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) +#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ + +/* +** CAPI3REF: Flags For File Open Operations +** +** These bit values are intended for use in the +** 3rd parameter to the [sqlite3_open_v2()] interface and +** in the 4th parameter to the [sqlite3_vfs.xOpen] method. +** +** Only those flags marked as "Ok for sqlite3_open_v2()" may be +** used as the third argument to the [sqlite3_open_v2()] interface. +** The other flags have historically been ignored by sqlite3_open_v2(), +** though future versions of SQLite might change so that an error is +** raised if any of the disallowed bits are passed into sqlite3_open_v2(). +** Applications should not depend on the historical behavior. +** +** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into +** [sqlite3_open_v2()] does *not* cause the underlying database file +** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into +** [sqlite3_open_v2()] has historically be a no-op and might become an +** error in future versions of SQLite. +*/ +#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ +#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ +#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ +#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ +#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ +#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ +#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ +#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ +#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ +#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ +#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ +#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ + +/* Reserved: 0x00F00000 */ +/* Legacy compatibility: */ +#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ + + +/* +** CAPI3REF: Device Characteristics +** +** The xDeviceCharacteristics method of the [sqlite3_io_methods] +** object returns an integer which is a vector of these +** bit values expressing I/O characteristics of the mass storage +** device that holds the file that the [sqlite3_io_methods] +** refers to. +** +** The SQLITE_IOCAP_ATOMIC property means that all writes of +** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values +** mean that writes of blocks that are nnn bytes in size and +** are aligned to an address which is an integer multiple of +** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means +** that when data is appended to a file, the data is appended +** first then the size of the file is extended, never the other +** way around. The SQLITE_IOCAP_SEQUENTIAL property means that +** information is written to disk in the same order as calls +** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that +** after reboot following a crash or power loss, the only bytes in a +** file that were written at the application level might have changed +** and that adjacent bytes, even bytes within the same sector are +** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN +** flag indicates that a file cannot be deleted when open. The +** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on +** read-only media and cannot be changed even by processes with +** elevated privileges. +** +** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying +** filesystem supports doing multiple write operations atomically when those +** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and +** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. +*/ +#define SQLITE_IOCAP_ATOMIC 0x00000001 +#define SQLITE_IOCAP_ATOMIC512 0x00000002 +#define SQLITE_IOCAP_ATOMIC1K 0x00000004 +#define SQLITE_IOCAP_ATOMIC2K 0x00000008 +#define SQLITE_IOCAP_ATOMIC4K 0x00000010 +#define SQLITE_IOCAP_ATOMIC8K 0x00000020 +#define SQLITE_IOCAP_ATOMIC16K 0x00000040 +#define SQLITE_IOCAP_ATOMIC32K 0x00000080 +#define SQLITE_IOCAP_ATOMIC64K 0x00000100 +#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 +#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 +#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 +#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 +#define SQLITE_IOCAP_IMMUTABLE 0x00002000 +#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 + +/* +** CAPI3REF: File Locking Levels +** +** SQLite uses one of these integer values as the second +** argument to calls it makes to the xLock() and xUnlock() methods +** of an [sqlite3_io_methods] object. These values are ordered from +** lest restrictive to most restrictive. +** +** The argument to xLock() is always SHARED or higher. The argument to +** xUnlock is either SHARED or NONE. +*/ +#define SQLITE_LOCK_NONE 0 /* xUnlock() only */ +#define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ +#define SQLITE_LOCK_RESERVED 2 /* xLock() only */ +#define SQLITE_LOCK_PENDING 3 /* xLock() only */ +#define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ + +/* +** CAPI3REF: Synchronization Type Flags +** +** When SQLite invokes the xSync() method of an +** [sqlite3_io_methods] object it uses a combination of +** these integer values as the second argument. +** +** When the SQLITE_SYNC_DATAONLY flag is used, it means that the +** sync operation only needs to flush data to mass storage. Inode +** information need not be flushed. If the lower four bits of the flag +** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. +** If the lower four bits equal SQLITE_SYNC_FULL, that means +** to use Mac OS X style fullsync instead of fsync(). +** +** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags +** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL +** settings. The [synchronous pragma] determines when calls to the +** xSync VFS method occur and applies uniformly across all platforms. +** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how +** energetic or rigorous or forceful the sync operations are and +** only make a difference on Mac OSX for the default SQLite code. +** (Third-party VFS implementations might also make the distinction +** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the +** operating systems natively supported by SQLite, only Mac OSX +** cares about the difference.) +*/ +#define SQLITE_SYNC_NORMAL 0x00002 +#define SQLITE_SYNC_FULL 0x00003 +#define SQLITE_SYNC_DATAONLY 0x00010 + +/* +** CAPI3REF: OS Interface Open File Handle +** +** An [sqlite3_file] object represents an open file in the +** [sqlite3_vfs | OS interface layer]. Individual OS interface +** implementations will +** want to subclass this object by appending additional fields +** for their own use. The pMethods entry is a pointer to an +** [sqlite3_io_methods] object that defines methods for performing +** I/O operations on the open file. +*/ +typedef struct sqlite3_file sqlite3_file; +struct sqlite3_file { + const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ +}; + +/* +** CAPI3REF: OS Interface File Virtual Methods Object +** +** Every file opened by the [sqlite3_vfs.xOpen] method populates an +** [sqlite3_file] object (or, more commonly, a subclass of the +** [sqlite3_file] object) with a pointer to an instance of this object. +** This object defines the methods used to perform various operations +** against the open file represented by the [sqlite3_file] object. +** +** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element +** to a non-NULL pointer, then the sqlite3_io_methods.xClose method +** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The +** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] +** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element +** to NULL. +** +** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or +** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). +** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] +** flag may be ORed in to indicate that only the data of the file +** and not its inode needs to be synced. +** +** The integer values to xLock() and xUnlock() are one of +** <ul> +** <li> [SQLITE_LOCK_NONE], +** <li> [SQLITE_LOCK_SHARED], +** <li> [SQLITE_LOCK_RESERVED], +** <li> [SQLITE_LOCK_PENDING], or +** <li> [SQLITE_LOCK_EXCLUSIVE]. +** </ul> +** xLock() upgrades the database file lock. In other words, xLock() moves the +** database file lock in the direction NONE toward EXCLUSIVE. The argument to +** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never +** SQLITE_LOCK_NONE. If the database file lock is already at or above the +** requested lock, then the call to xLock() is a no-op. +** xUnlock() downgrades the database file lock to either SHARED or NONE. +* If the lock is already at or below the requested lock state, then the call +** to xUnlock() is a no-op. +** The xCheckReservedLock() method checks whether any database connection, +** either in this process or in some other process, is holding a RESERVED, +** PENDING, or EXCLUSIVE lock on the file. It returns true +** if such a lock exists and false otherwise. +** +** The xFileControl() method is a generic interface that allows custom +** VFS implementations to directly control an open file using the +** [sqlite3_file_control()] interface. The second "op" argument is an +** integer opcode. The third argument is a generic pointer intended to +** point to a structure that may contain arguments or space in which to +** write return values. Potential uses for xFileControl() might be +** functions to enable blocking locks with timeouts, to change the +** locking strategy (for example to use dot-file locks), to inquire +** about the status of a lock, or to break stale locks. The SQLite +** core reserves all opcodes less than 100 for its own use. +** A [file control opcodes | list of opcodes] less than 100 is available. +** Applications that define a custom xFileControl method should use opcodes +** greater than 100 to avoid conflicts. VFS implementations should +** return [SQLITE_NOTFOUND] for file control opcodes that they do not +** recognize. +** +** The xSectorSize() method returns the sector size of the +** device that underlies the file. The sector size is the +** minimum write that can be performed without disturbing +** other bytes in the file. The xDeviceCharacteristics() +** method returns a bit vector describing behaviors of the +** underlying device: +** +** <ul> +** <li> [SQLITE_IOCAP_ATOMIC] +** <li> [SQLITE_IOCAP_ATOMIC512] +** <li> [SQLITE_IOCAP_ATOMIC1K] +** <li> [SQLITE_IOCAP_ATOMIC2K] +** <li> [SQLITE_IOCAP_ATOMIC4K] +** <li> [SQLITE_IOCAP_ATOMIC8K] +** <li> [SQLITE_IOCAP_ATOMIC16K] +** <li> [SQLITE_IOCAP_ATOMIC32K] +** <li> [SQLITE_IOCAP_ATOMIC64K] +** <li> [SQLITE_IOCAP_SAFE_APPEND] +** <li> [SQLITE_IOCAP_SEQUENTIAL] +** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] +** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] +** <li> [SQLITE_IOCAP_IMMUTABLE] +** <li> [SQLITE_IOCAP_BATCH_ATOMIC] +** </ul> +** +** The SQLITE_IOCAP_ATOMIC property means that all writes of +** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values +** mean that writes of blocks that are nnn bytes in size and +** are aligned to an address which is an integer multiple of +** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means +** that when data is appended to a file, the data is appended +** first then the size of the file is extended, never the other +** way around. The SQLITE_IOCAP_SEQUENTIAL property means that +** information is written to disk in the same order as calls +** to xWrite(). +** +** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill +** in the unread portions of the buffer with zeros. A VFS that +** fails to zero-fill short reads might seem to work. However, +** failure to zero-fill short reads will eventually lead to +** database corruption. +*/ +typedef struct sqlite3_io_methods sqlite3_io_methods; +struct sqlite3_io_methods { + int iVersion; + int (*xClose)(sqlite3_file*); + int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); + int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); + int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); + int (*xSync)(sqlite3_file*, int flags); + int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); + int (*xLock)(sqlite3_file*, int); + int (*xUnlock)(sqlite3_file*, int); + int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); + int (*xFileControl)(sqlite3_file*, int op, void *pArg); + int (*xSectorSize)(sqlite3_file*); + int (*xDeviceCharacteristics)(sqlite3_file*); + /* Methods above are valid for version 1 */ + int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); + int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); + void (*xShmBarrier)(sqlite3_file*); + int (*xShmUnmap)(sqlite3_file*, int deleteFlag); + /* Methods above are valid for version 2 */ + int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); + int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); + /* Methods above are valid for version 3 */ + /* Additional methods may be added in future releases */ +}; + +/* +** CAPI3REF: Standard File Control Opcodes +** KEYWORDS: {file control opcodes} {file control opcode} +** +** These integer constants are opcodes for the xFileControl method +** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] +** interface. +** +** <ul> +** <li>[[SQLITE_FCNTL_LOCKSTATE]] +** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This +** opcode causes the xFileControl method to write the current state of +** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], +** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) +** into an integer that the pArg argument points to. +** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. +** +** <li>[[SQLITE_FCNTL_SIZE_HINT]] +** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS +** layer a hint of how large the database file will grow to be during the +** current transaction. This hint is not guaranteed to be accurate but it +** is often close. The underlying VFS might choose to preallocate database +** file space based on this hint in order to help writes to the database +** file run faster. +** +** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] +** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that +** implements [sqlite3_deserialize()] to set an upper bound on the size +** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. +** If the integer pointed to is negative, then it is filled in with the +** current limit. Otherwise the limit is set to the larger of the value +** of the integer pointed to and the current database size. The integer +** pointed to is set to the new limit. +** +** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] +** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS +** extends and truncates the database file in chunks of a size specified +** by the user. The fourth argument to [sqlite3_file_control()] should +** point to an integer (type int) containing the new chunk-size to use +** for the nominated database. Allocating database file space in large +** chunks (say 1MB at a time), may reduce file-system fragmentation and +** improve performance on some systems. +** +** <li>[[SQLITE_FCNTL_FILE_POINTER]] +** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer +** to the [sqlite3_file] object associated with a particular database +** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. +** +** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] +** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer +** to the [sqlite3_file] object associated with the journal file (either +** the [rollback journal] or the [write-ahead log]) for a particular database +** connection. See also [SQLITE_FCNTL_FILE_POINTER]. +** +** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] +** No longer in use. +** +** <li>[[SQLITE_FCNTL_SYNC]] +** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and +** sent to the VFS immediately before the xSync method is invoked on a +** database file descriptor. Or, if the xSync method is not invoked +** because the user has configured SQLite with +** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place +** of the xSync method. In most cases, the pointer argument passed with +** this file-control is NULL. However, if the database file is being synced +** as part of a multi-database commit, the argument points to a nul-terminated +** string containing the transactions super-journal file name. VFSes that +** do not need this signal should silently ignore this opcode. Applications +** should not call [sqlite3_file_control()] with this opcode as doing so may +** disrupt the operation of the specialized VFSes that do require it. +** +** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] +** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite +** and sent to the VFS after a transaction has been committed immediately +** but before the database is unlocked. VFSes that do not need this signal +** should silently ignore this opcode. Applications should not call +** [sqlite3_file_control()] with this opcode as doing so may disrupt the +** operation of the specialized VFSes that do require it. +** +** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] +** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic +** retry counts and intervals for certain disk I/O operations for the +** windows [VFS] in order to provide robustness in the presence of +** anti-virus programs. By default, the windows VFS will retry file read, +** file write, and file delete operations up to 10 times, with a delay +** of 25 milliseconds before the first retry and with the delay increasing +** by an additional 25 milliseconds with each subsequent retry. This +** opcode allows these two values (10 retries and 25 milliseconds of delay) +** to be adjusted. The values are changed for all database connections +** within the same process. The argument is a pointer to an array of two +** integers where the first integer is the new retry count and the second +** integer is the delay. If either integer is negative, then the setting +** is not changed but instead the prior value of that setting is written +** into the array entry, allowing the current retry settings to be +** interrogated. The zDbName parameter is ignored. +** +** <li>[[SQLITE_FCNTL_PERSIST_WAL]] +** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the +** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary +** write ahead log ([WAL file]) and shared memory +** files used for transaction control +** are automatically deleted when the latest connection to the database +** closes. Setting persistent WAL mode causes those files to persist after +** close. Persisting the files is useful when other processes that do not +** have write permission on the directory containing the database file want +** to read the database file, as the WAL and shared memory files must exist +** in order for the database to be readable. The fourth parameter to +** [sqlite3_file_control()] for this opcode should be a pointer to an integer. +** That integer is 0 to disable persistent WAL mode or 1 to enable persistent +** WAL mode. If the integer is -1, then it is overwritten with the current +** WAL persistence setting. +** +** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] +** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the +** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting +** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the +** xDeviceCharacteristics methods. The fourth parameter to +** [sqlite3_file_control()] for this opcode should be a pointer to an integer. +** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage +** mode. If the integer is -1, then it is overwritten with the current +** zero-damage mode setting. +** +** <li>[[SQLITE_FCNTL_OVERWRITE]] +** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening +** a write transaction to indicate that, unless it is rolled back for some +** reason, the entire database file will be overwritten by the current +** transaction. This is used by VACUUM operations. +** +** <li>[[SQLITE_FCNTL_VFSNAME]] +** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of +** all [VFSes] in the VFS stack. The names are of all VFS shims and the +** final bottom-level VFS are written into memory obtained from +** [sqlite3_malloc()] and the result is stored in the char* variable +** that the fourth parameter of [sqlite3_file_control()] points to. +** The caller is responsible for freeing the memory when done. As with +** all file-control actions, there is no guarantee that this will actually +** do anything. Callers should initialize the char* variable to a NULL +** pointer in case this file-control is not implemented. This file-control +** is intended for diagnostic use only. +** +** <li>[[SQLITE_FCNTL_VFS_POINTER]] +** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level +** [VFSes] currently in use. ^(The argument X in +** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be +** of type "[sqlite3_vfs] **". This opcodes will set *X +** to a pointer to the top-level VFS.)^ +** ^When there are multiple VFS shims in the stack, this opcode finds the +** upper-most shim only. +** +** <li>[[SQLITE_FCNTL_PRAGMA]] +** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] +** file control is sent to the open [sqlite3_file] object corresponding +** to the database file to which the pragma statement refers. ^The argument +** to the [SQLITE_FCNTL_PRAGMA] file control is an array of +** pointers to strings (char**) in which the second element of the array +** is the name of the pragma and the third element is the argument to the +** pragma or NULL if the pragma has no argument. ^The handler for an +** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element +** of the char** argument point to a string obtained from [sqlite3_mprintf()] +** or the equivalent and that string will become the result of the pragma or +** the error message if the pragma fails. ^If the +** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal +** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] +** file control returns [SQLITE_OK], then the parser assumes that the +** VFS has handled the PRAGMA itself and the parser generates a no-op +** prepared statement if result string is NULL, or that returns a copy +** of the result string if the string is non-NULL. +** ^If the [SQLITE_FCNTL_PRAGMA] file control returns +** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means +** that the VFS encountered an error while handling the [PRAGMA] and the +** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] +** file control occurs at the beginning of pragma statement analysis and so +** it is able to override built-in [PRAGMA] statements. +** +** <li>[[SQLITE_FCNTL_BUSYHANDLER]] +** ^The [SQLITE_FCNTL_BUSYHANDLER] +** file-control may be invoked by SQLite on the database file handle +** shortly after it is opened in order to provide a custom VFS with access +** to the connection's busy-handler callback. The argument is of type (void**) +** - an array of two (void *) values. The first (void *) actually points +** to a function of type (int (*)(void *)). In order to invoke the connection's +** busy-handler, this function should be invoked with the second (void *) in +** the array as the only argument. If it returns non-zero, then the operation +** should be retried. If it returns zero, the custom VFS should abandon the +** current operation. +** +** <li>[[SQLITE_FCNTL_TEMPFILENAME]] +** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control +** to have SQLite generate a +** temporary filename using the same algorithm that is followed to generate +** temporary filenames for TEMP tables and other internal uses. The +** argument should be a char** which will be filled with the filename +** written into memory obtained from [sqlite3_malloc()]. The caller should +** invoke [sqlite3_free()] on the result to avoid a memory leak. +** +** <li>[[SQLITE_FCNTL_MMAP_SIZE]] +** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the +** maximum number of bytes that will be used for memory-mapped I/O. +** The argument is a pointer to a value of type sqlite3_int64 that +** is an advisory maximum number of bytes in the file to memory map. The +** pointer is overwritten with the old value. The limit is not changed if +** the value originally pointed to is negative, and so the current limit +** can be queried by passing in a pointer to a negative number. This +** file-control is used internally to implement [PRAGMA mmap_size]. +** +** <li>[[SQLITE_FCNTL_TRACE]] +** The [SQLITE_FCNTL_TRACE] file control provides advisory information +** to the VFS about what the higher layers of the SQLite stack are doing. +** This file control is used by some VFS activity tracing [shims]. +** The argument is a zero-terminated string. Higher layers in the +** SQLite stack may generate instances of this file control if +** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. +** +** <li>[[SQLITE_FCNTL_HAS_MOVED]] +** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a +** pointer to an integer and it writes a boolean into that integer depending +** on whether or not the file has been renamed, moved, or deleted since it +** was first opened. +** +** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] +** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the +** underlying native file handle associated with a file handle. This file +** control interprets its argument as a pointer to a native file handle and +** writes the resulting value there. +** +** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] +** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This +** opcode causes the xFileControl method to swap the file handle with the one +** pointed to by the pArg argument. This capability is used during testing +** and only needs to be supported when SQLITE_TEST is defined. +** +** <li>[[SQLITE_FCNTL_WAL_BLOCK]] +** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might +** be advantageous to block on the next WAL lock if the lock is not immediately +** available. The WAL subsystem issues this signal during rare +** circumstances in order to fix a problem with priority inversion. +** Applications should <em>not</em> use this file-control. +** +** <li>[[SQLITE_FCNTL_ZIPVFS]] +** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other +** VFS should return SQLITE_NOTFOUND for this opcode. +** +** <li>[[SQLITE_FCNTL_RBU]] +** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by +** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for +** this opcode. +** +** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] +** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then +** the file descriptor is placed in "batch write mode", which +** means all subsequent write operations will be deferred and done +** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems +** that do not support batch atomic writes will return SQLITE_NOTFOUND. +** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to +** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or +** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make +** no VFS interface calls on the same [sqlite3_file] file descriptor +** except for calls to the xWrite method and the xFileControl method +** with [SQLITE_FCNTL_SIZE_HINT]. +** +** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] +** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write +** operations since the previous successful call to +** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. +** This file control returns [SQLITE_OK] if and only if the writes were +** all performed successfully and have been committed to persistent storage. +** ^Regardless of whether or not it is successful, this file control takes +** the file descriptor out of batch write mode so that all subsequent +** write operations are independent. +** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without +** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. +** +** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] +** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write +** operations since the previous successful call to +** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. +** ^This file control takes the file descriptor out of batch write mode +** so that all subsequent write operations are independent. +** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without +** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. +** +** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] +** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS +** to block for up to M milliseconds before failing when attempting to +** obtain a file lock using the xLock or xShmLock methods of the VFS. +** The parameter is a pointer to a 32-bit signed integer that contains +** the value that M is to be set to. Before returning, the 32-bit signed +** integer is overwritten with the previous value of M. +** +** <li>[[SQLITE_FCNTL_DATA_VERSION]] +** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to +** a database file. The argument is a pointer to a 32-bit unsigned integer. +** The "data version" for the pager is written into the pointer. The +** "data version" changes whenever any change occurs to the corresponding +** database file, either through SQL statements on the same database +** connection or through transactions committed by separate database +** connections possibly in other processes. The [sqlite3_total_changes()] +** interface can be used to find if any database on the connection has changed, +** but that interface responds to changes on TEMP as well as MAIN and does +** not provide a mechanism to detect changes to MAIN only. Also, the +** [sqlite3_total_changes()] interface responds to internal changes only and +** omits changes made by other database connections. The +** [PRAGMA data_version] command provides a mechanism to detect changes to +** a single attached database that occur due to other database connections, +** but omits changes implemented by the database connection on which it is +** called. This file control is the only mechanism to detect changes that +** happen either internally or externally and that are associated with +** a particular attached database. +** +** <li>[[SQLITE_FCNTL_CKPT_START]] +** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint +** in wal mode before the client starts to copy pages from the wal +** file to the database file. +** +** <li>[[SQLITE_FCNTL_CKPT_DONE]] +** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint +** in wal mode after the client has finished copying pages from the wal +** file to the database file, but before the *-shm file is updated to +** record the fact that the pages have been checkpointed. +** </ul> +** +** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] +** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect +** whether or not there is a database client in another process with a wal-mode +** transaction open on the database or not. It is only available on unix.The +** (void*) argument passed with this file-control should be a pointer to a +** value of type (int). The integer value is set to 1 if the database is a wal +** mode database and there exists at least one client in another process that +** currently has an SQL transaction open on the database. It is set to 0 if +** the database is not a wal-mode db, or if there is no such connection in any +** other process. This opcode cannot be used to detect transactions opened +** by clients within the current process, only within other processes. +** </ul> +** +** <li>[[SQLITE_FCNTL_CKSM_FILE]] +** Used by the cksmvfs VFS module only. +** +** <li>[[SQLITE_FCNTL_RESET_CACHE]] +** If there is currently no transaction open on the database, and the +** database is not a temp db, then this file-control purges the contents +** of the in-memory page cache. If there is an open transaction, or if +** the db is a temp-db, it is a no-op, not an error. +** </ul> +*/ +#define SQLITE_FCNTL_LOCKSTATE 1 +#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 +#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 +#define SQLITE_FCNTL_LAST_ERRNO 4 +#define SQLITE_FCNTL_SIZE_HINT 5 +#define SQLITE_FCNTL_CHUNK_SIZE 6 +#define SQLITE_FCNTL_FILE_POINTER 7 +#define SQLITE_FCNTL_SYNC_OMITTED 8 +#define SQLITE_FCNTL_WIN32_AV_RETRY 9 +#define SQLITE_FCNTL_PERSIST_WAL 10 +#define SQLITE_FCNTL_OVERWRITE 11 +#define SQLITE_FCNTL_VFSNAME 12 +#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 +#define SQLITE_FCNTL_PRAGMA 14 +#define SQLITE_FCNTL_BUSYHANDLER 15 +#define SQLITE_FCNTL_TEMPFILENAME 16 +#define SQLITE_FCNTL_MMAP_SIZE 18 +#define SQLITE_FCNTL_TRACE 19 +#define SQLITE_FCNTL_HAS_MOVED 20 +#define SQLITE_FCNTL_SYNC 21 +#define SQLITE_FCNTL_COMMIT_PHASETWO 22 +#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 +#define SQLITE_FCNTL_WAL_BLOCK 24 +#define SQLITE_FCNTL_ZIPVFS 25 +#define SQLITE_FCNTL_RBU 26 +#define SQLITE_FCNTL_VFS_POINTER 27 +#define SQLITE_FCNTL_JOURNAL_POINTER 28 +#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 +#define SQLITE_FCNTL_PDB 30 +#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 +#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 +#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 +#define SQLITE_FCNTL_LOCK_TIMEOUT 34 +#define SQLITE_FCNTL_DATA_VERSION 35 +#define SQLITE_FCNTL_SIZE_LIMIT 36 +#define SQLITE_FCNTL_CKPT_DONE 37 +#define SQLITE_FCNTL_RESERVE_BYTES 38 +#define SQLITE_FCNTL_CKPT_START 39 +#define SQLITE_FCNTL_EXTERNAL_READER 40 +#define SQLITE_FCNTL_CKSM_FILE 41 +#define SQLITE_FCNTL_RESET_CACHE 42 + +/* deprecated names */ +#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE +#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE +#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO + + +/* +** CAPI3REF: Mutex Handle +** +** The mutex module within SQLite defines [sqlite3_mutex] to be an +** abstract type for a mutex object. The SQLite core never looks +** at the internal representation of an [sqlite3_mutex]. It only +** deals with pointers to the [sqlite3_mutex] object. +** +** Mutexes are created using [sqlite3_mutex_alloc()]. +*/ +typedef struct sqlite3_mutex sqlite3_mutex; + +/* +** CAPI3REF: Loadable Extension Thunk +** +** A pointer to the opaque sqlite3_api_routines structure is passed as +** the third parameter to entry points of [loadable extensions]. This +** structure must be typedefed in order to work around compiler warnings +** on some platforms. +*/ +typedef struct sqlite3_api_routines sqlite3_api_routines; + +/* +** CAPI3REF: File Name +** +** Type [sqlite3_filename] is used by SQLite to pass filenames to the +** xOpen method of a [VFS]. It may be cast to (const char*) and treated +** as a normal, nul-terminated, UTF-8 buffer containing the filename, but +** may also be passed to special APIs such as: +** +** <ul> +** <li> sqlite3_filename_database() +** <li> sqlite3_filename_journal() +** <li> sqlite3_filename_wal() +** <li> sqlite3_uri_parameter() +** <li> sqlite3_uri_boolean() +** <li> sqlite3_uri_int64() +** <li> sqlite3_uri_key() +** </ul> +*/ +typedef const char *sqlite3_filename; + +/* +** CAPI3REF: OS Interface Object +** +** An instance of the sqlite3_vfs object defines the interface between +** the SQLite core and the underlying operating system. The "vfs" +** in the name of the object stands for "virtual file system". See +** the [VFS | VFS documentation] for further information. +** +** The VFS interface is sometimes extended by adding new methods onto +** the end. Each time such an extension occurs, the iVersion field +** is incremented. The iVersion value started out as 1 in +** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 +** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased +** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields +** may be appended to the sqlite3_vfs object and the iVersion value +** may increase again in future versions of SQLite. +** Note that due to an oversight, the structure +** of the sqlite3_vfs object changed in the transition from +** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] +** and yet the iVersion field was not increased. +** +** The szOsFile field is the size of the subclassed [sqlite3_file] +** structure used by this VFS. mxPathname is the maximum length of +** a pathname in this VFS. +** +** Registered sqlite3_vfs objects are kept on a linked list formed by +** the pNext pointer. The [sqlite3_vfs_register()] +** and [sqlite3_vfs_unregister()] interfaces manage this list +** in a thread-safe way. The [sqlite3_vfs_find()] interface +** searches the list. Neither the application code nor the VFS +** implementation should use the pNext pointer. +** +** The pNext field is the only field in the sqlite3_vfs +** structure that SQLite will ever modify. SQLite will only access +** or modify this field while holding a particular static mutex. +** The application should never modify anything within the sqlite3_vfs +** object once the object has been registered. +** +** The zName field holds the name of the VFS module. The name must +** be unique across all VFS modules. +** +** [[sqlite3_vfs.xOpen]] +** ^SQLite guarantees that the zFilename parameter to xOpen +** is either a NULL pointer or string obtained +** from xFullPathname() with an optional suffix added. +** ^If a suffix is added to the zFilename parameter, it will +** consist of a single "-" character followed by no more than +** 11 alphanumeric and/or "-" characters. +** ^SQLite further guarantees that +** the string will be valid and unchanged until xClose() is +** called. Because of the previous sentence, +** the [sqlite3_file] can safely store a pointer to the +** filename if it needs to remember the filename for some reason. +** If the zFilename parameter to xOpen is a NULL pointer then xOpen +** must invent its own temporary name for the file. ^Whenever the +** xFilename parameter is NULL it will also be the case that the +** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. +** +** The flags argument to xOpen() includes all bits set in +** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] +** or [sqlite3_open16()] is used, then flags includes at least +** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. +** If xOpen() opens a file read-only then it sets *pOutFlags to +** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. +** +** ^(SQLite will also add one of the following flags to the xOpen() +** call, depending on the object being opened: +** +** <ul> +** <li> [SQLITE_OPEN_MAIN_DB] +** <li> [SQLITE_OPEN_MAIN_JOURNAL] +** <li> [SQLITE_OPEN_TEMP_DB] +** <li> [SQLITE_OPEN_TEMP_JOURNAL] +** <li> [SQLITE_OPEN_TRANSIENT_DB] +** <li> [SQLITE_OPEN_SUBJOURNAL] +** <li> [SQLITE_OPEN_SUPER_JOURNAL] +** <li> [SQLITE_OPEN_WAL] +** </ul>)^ +** +** The file I/O implementation can use the object type flags to +** change the way it deals with files. For example, an application +** that does not care about crash recovery or rollback might make +** the open of a journal file a no-op. Writes to this journal would +** also be no-ops, and any attempt to read the journal would return +** SQLITE_IOERR. Or the implementation might recognize that a database +** file will be doing page-aligned sector reads and writes in a random +** order and set up its I/O subsystem accordingly. +** +** SQLite might also add one of the following flags to the xOpen method: +** +** <ul> +** <li> [SQLITE_OPEN_DELETEONCLOSE] +** <li> [SQLITE_OPEN_EXCLUSIVE] +** </ul> +** +** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be +** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] +** will be set for TEMP databases and their journals, transient +** databases, and subjournals. +** +** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction +** with the [SQLITE_OPEN_CREATE] flag, which are both directly +** analogous to the O_EXCL and O_CREAT flags of the POSIX open() +** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the +** SQLITE_OPEN_CREATE, is used to indicate that file should always +** be created, and that it is an error if it already exists. +** It is <i>not</i> used to indicate the file should be opened +** for exclusive access. +** +** ^At least szOsFile bytes of memory are allocated by SQLite +** to hold the [sqlite3_file] structure passed as the third +** argument to xOpen. The xOpen method does not have to +** allocate the structure; it should just fill it in. Note that +** the xOpen method must set the sqlite3_file.pMethods to either +** a valid [sqlite3_io_methods] object or to NULL. xOpen must do +** this even if the open fails. SQLite expects that the sqlite3_file.pMethods +** element will be valid after xOpen returns regardless of the success +** or failure of the xOpen call. +** +** [[sqlite3_vfs.xAccess]] +** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] +** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to +** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] +** to test whether a file is at least readable. The SQLITE_ACCESS_READ +** flag is never actually used and is not implemented in the built-in +** VFSes of SQLite. The file is named by the second argument and can be a +** directory. The xAccess method returns [SQLITE_OK] on success or some +** non-zero error code if there is an I/O error or if the name of +** the file given in the second argument is illegal. If SQLITE_OK +** is returned, then non-zero or zero is written into *pResOut to indicate +** whether or not the file is accessible. +** +** ^SQLite will always allocate at least mxPathname+1 bytes for the +** output buffer xFullPathname. The exact size of the output buffer +** is also passed as a parameter to both methods. If the output buffer +** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is +** handled as a fatal error by SQLite, vfs implementations should endeavor +** to prevent this by setting mxPathname to a sufficiently large value. +** +** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() +** interfaces are not strictly a part of the filesystem, but they are +** included in the VFS structure for completeness. +** The xRandomness() function attempts to return nBytes bytes +** of good-quality randomness into zOut. The return value is +** the actual number of bytes of randomness obtained. +** The xSleep() method causes the calling thread to sleep for at +** least the number of microseconds given. ^The xCurrentTime() +** method returns a Julian Day Number for the current date and time as +** a floating point value. +** ^The xCurrentTimeInt64() method returns, as an integer, the Julian +** Day Number multiplied by 86400000 (the number of milliseconds in +** a 24-hour day). +** ^SQLite will use the xCurrentTimeInt64() method to get the current +** date and time if that method is available (if iVersion is 2 or +** greater and the function pointer is not NULL) and will fall back +** to xCurrentTime() if xCurrentTimeInt64() is unavailable. +** +** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces +** are not used by the SQLite core. These optional interfaces are provided +** by some VFSes to facilitate testing of the VFS code. By overriding +** system calls with functions under its control, a test program can +** simulate faults and error conditions that would otherwise be difficult +** or impossible to induce. The set of system calls that can be overridden +** varies from one VFS to another, and from one version of the same VFS to the +** next. Applications that use these interfaces must be prepared for any +** or all of these interfaces to be NULL or for their behavior to change +** from one release to the next. Applications must not attempt to access +** any of these methods if the iVersion of the VFS is less than 3. +*/ +typedef struct sqlite3_vfs sqlite3_vfs; +typedef void (*sqlite3_syscall_ptr)(void); +struct sqlite3_vfs { + int iVersion; /* Structure version number (currently 3) */ + int szOsFile; /* Size of subclassed sqlite3_file */ + int mxPathname; /* Maximum file pathname length */ + sqlite3_vfs *pNext; /* Next registered VFS */ + const char *zName; /* Name of this virtual file system */ + void *pAppData; /* Pointer to application-specific data */ + int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, + int flags, int *pOutFlags); + int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); + int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); + int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); + void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); + void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); + void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); + void (*xDlClose)(sqlite3_vfs*, void*); + int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); + int (*xSleep)(sqlite3_vfs*, int microseconds); + int (*xCurrentTime)(sqlite3_vfs*, double*); + int (*xGetLastError)(sqlite3_vfs*, int, char *); + /* + ** The methods above are in version 1 of the sqlite_vfs object + ** definition. Those that follow are added in version 2 or later + */ + int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); + /* + ** The methods above are in versions 1 and 2 of the sqlite_vfs object. + ** Those below are for version 3 and greater. + */ + int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); + sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); + const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); + /* + ** The methods above are in versions 1 through 3 of the sqlite_vfs object. + ** New fields may be appended in future versions. The iVersion + ** value will increment whenever this happens. + */ +}; + +/* +** CAPI3REF: Flags for the xAccess VFS method +** +** These integer constants can be used as the third parameter to +** the xAccess method of an [sqlite3_vfs] object. They determine +** what kind of permissions the xAccess method is looking for. +** With SQLITE_ACCESS_EXISTS, the xAccess method +** simply checks whether the file exists. +** With SQLITE_ACCESS_READWRITE, the xAccess method +** checks whether the named directory is both readable and writable +** (in other words, if files can be added, removed, and renamed within +** the directory). +** The SQLITE_ACCESS_READWRITE constant is currently used only by the +** [temp_store_directory pragma], though this could change in a future +** release of SQLite. +** With SQLITE_ACCESS_READ, the xAccess method +** checks whether the file is readable. The SQLITE_ACCESS_READ constant is +** currently unused, though it might be used in a future release of +** SQLite. +*/ +#define SQLITE_ACCESS_EXISTS 0 +#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ +#define SQLITE_ACCESS_READ 2 /* Unused */ + +/* +** CAPI3REF: Flags for the xShmLock VFS method +** +** These integer constants define the various locking operations +** allowed by the xShmLock method of [sqlite3_io_methods]. The +** following are the only legal combinations of flags to the +** xShmLock method: +** +** <ul> +** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED +** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE +** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED +** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE +** </ul> +** +** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as +** was given on the corresponding lock. +** +** The xShmLock method can transition between unlocked and SHARED or +** between unlocked and EXCLUSIVE. It cannot transition between SHARED +** and EXCLUSIVE. +*/ +#define SQLITE_SHM_UNLOCK 1 +#define SQLITE_SHM_LOCK 2 +#define SQLITE_SHM_SHARED 4 +#define SQLITE_SHM_EXCLUSIVE 8 + +/* +** CAPI3REF: Maximum xShmLock index +** +** The xShmLock method on [sqlite3_io_methods] may use values +** between 0 and this upper bound as its "offset" argument. +** The SQLite core will never attempt to acquire or release a +** lock outside of this range +*/ +#define SQLITE_SHM_NLOCK 8 + + +/* +** CAPI3REF: Initialize The SQLite Library +** +** ^The sqlite3_initialize() routine initializes the +** SQLite library. ^The sqlite3_shutdown() routine +** deallocates any resources that were allocated by sqlite3_initialize(). +** These routines are designed to aid in process initialization and +** shutdown on embedded systems. Workstation applications using +** SQLite normally do not need to invoke either of these routines. +** +** A call to sqlite3_initialize() is an "effective" call if it is +** the first time sqlite3_initialize() is invoked during the lifetime of +** the process, or if it is the first time sqlite3_initialize() is invoked +** following a call to sqlite3_shutdown(). ^(Only an effective call +** of sqlite3_initialize() does any initialization. All other calls +** are harmless no-ops.)^ +** +** A call to sqlite3_shutdown() is an "effective" call if it is the first +** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only +** an effective call to sqlite3_shutdown() does any deinitialization. +** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ +** +** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() +** is not. The sqlite3_shutdown() interface must only be called from a +** single thread. All open [database connections] must be closed and all +** other SQLite resources must be deallocated prior to invoking +** sqlite3_shutdown(). +** +** Among other things, ^sqlite3_initialize() will invoke +** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() +** will invoke sqlite3_os_end(). +** +** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. +** ^If for some reason, sqlite3_initialize() is unable to initialize +** the library (perhaps it is unable to allocate a needed resource such +** as a mutex) it returns an [error code] other than [SQLITE_OK]. +** +** ^The sqlite3_initialize() routine is called internally by many other +** SQLite interfaces so that an application usually does not need to +** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] +** calls sqlite3_initialize() so the SQLite library will be automatically +** initialized when [sqlite3_open()] is called if it has not be initialized +** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] +** compile-time option, then the automatic calls to sqlite3_initialize() +** are omitted and the application must call sqlite3_initialize() directly +** prior to using any other SQLite interface. For maximum portability, +** it is recommended that applications always invoke sqlite3_initialize() +** directly prior to using any other SQLite interface. Future releases +** of SQLite may require this. In other words, the behavior exhibited +** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the +** default behavior in some future release of SQLite. +** +** The sqlite3_os_init() routine does operating-system specific +** initialization of the SQLite library. The sqlite3_os_end() +** routine undoes the effect of sqlite3_os_init(). Typical tasks +** performed by these routines include allocation or deallocation +** of static resources, initialization of global variables, +** setting up a default [sqlite3_vfs] module, or setting up +** a default configuration using [sqlite3_config()]. +** +** The application should never invoke either sqlite3_os_init() +** or sqlite3_os_end() directly. The application should only invoke +** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() +** interface is called automatically by sqlite3_initialize() and +** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate +** implementations for sqlite3_os_init() and sqlite3_os_end() +** are built into SQLite when it is compiled for Unix, Windows, or OS/2. +** When [custom builds | built for other platforms] +** (using the [SQLITE_OS_OTHER=1] compile-time +** option) the application must supply a suitable implementation for +** sqlite3_os_init() and sqlite3_os_end(). An application-supplied +** implementation of sqlite3_os_init() or sqlite3_os_end() +** must return [SQLITE_OK] on success and some other [error code] upon +** failure. +*/ +int sqlite3_initialize(void); +int sqlite3_shutdown(void); +int sqlite3_os_init(void); +int sqlite3_os_end(void); + +/* +** CAPI3REF: Configuring The SQLite Library +** +** The sqlite3_config() interface is used to make global configuration +** changes to SQLite in order to tune SQLite to the specific needs of +** the application. The default configuration is recommended for most +** applications and so this routine is usually not necessary. It is +** provided to support rare applications with unusual needs. +** +** <b>The sqlite3_config() interface is not threadsafe. The application +** must ensure that no other SQLite interfaces are invoked by other +** threads while sqlite3_config() is running.</b> +** +** The sqlite3_config() interface +** may only be invoked prior to library initialization using +** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. +** ^If sqlite3_config() is called after [sqlite3_initialize()] and before +** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. +** Note, however, that ^sqlite3_config() can be called as part of the +** implementation of an application-defined [sqlite3_os_init()]. +** +** The first argument to sqlite3_config() is an integer +** [configuration option] that determines +** what property of SQLite is to be configured. Subsequent arguments +** vary depending on the [configuration option] +** in the first argument. +** +** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. +** ^If the option is unknown or SQLite is unable to set the option +** then this routine returns a non-zero [error code]. +*/ +int sqlite3_config(int, ...); + +/* +** CAPI3REF: Configure database connections +** METHOD: sqlite3 +** +** The sqlite3_db_config() interface is used to make configuration +** changes to a [database connection]. The interface is similar to +** [sqlite3_config()] except that the changes apply to a single +** [database connection] (specified in the first argument). +** +** The second argument to sqlite3_db_config(D,V,...) is the +** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code +** that indicates what aspect of the [database connection] is being configured. +** Subsequent arguments vary depending on the configuration verb. +** +** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if +** the call is considered successful. +*/ +int sqlite3_db_config(sqlite3*, int op, ...); + +/* +** CAPI3REF: Memory Allocation Routines +** +** An instance of this object defines the interface between SQLite +** and low-level memory allocation routines. +** +** This object is used in only one place in the SQLite interface. +** A pointer to an instance of this object is the argument to +** [sqlite3_config()] when the configuration option is +** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. +** By creating an instance of this object +** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) +** during configuration, an application can specify an alternative +** memory allocation subsystem for SQLite to use for all of its +** dynamic memory needs. +** +** Note that SQLite comes with several [built-in memory allocators] +** that are perfectly adequate for the overwhelming majority of applications +** and that this object is only useful to a tiny minority of applications +** with specialized memory allocation requirements. This object is +** also used during testing of SQLite in order to specify an alternative +** memory allocator that simulates memory out-of-memory conditions in +** order to verify that SQLite recovers gracefully from such +** conditions. +** +** The xMalloc, xRealloc, and xFree methods must work like the +** malloc(), realloc() and free() functions from the standard C library. +** ^SQLite guarantees that the second argument to +** xRealloc is always a value returned by a prior call to xRoundup. +** +** xSize should return the allocated size of a memory allocation +** previously obtained from xMalloc or xRealloc. The allocated size +** is always at least as big as the requested size but may be larger. +** +** The xRoundup method returns what would be the allocated size of +** a memory allocation given a particular requested size. Most memory +** allocators round up memory allocations at least to the next multiple +** of 8. Some allocators round up to a larger multiple or to a power of 2. +** Every memory allocation request coming in through [sqlite3_malloc()] +** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, +** that causes the corresponding memory allocation to fail. +** +** The xInit method initializes the memory allocator. For example, +** it might allocate any required mutexes or initialize internal data +** structures. The xShutdown method is invoked (indirectly) by +** [sqlite3_shutdown()] and should deallocate any resources acquired +** by xInit. The pAppData pointer is used as the only parameter to +** xInit and xShutdown. +** +** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes +** the xInit method, so the xInit method need not be threadsafe. The +** xShutdown method is only called from [sqlite3_shutdown()] so it does +** not need to be threadsafe either. For all other methods, SQLite +** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the +** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which +** it is by default) and so the methods are automatically serialized. +** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other +** methods must be threadsafe or else make their own arrangements for +** serialization. +** +** SQLite will never invoke xInit() more than once without an intervening +** call to xShutdown(). +*/ +typedef struct sqlite3_mem_methods sqlite3_mem_methods; +struct sqlite3_mem_methods { + void *(*xMalloc)(int); /* Memory allocation function */ + void (*xFree)(void*); /* Free a prior allocation */ + void *(*xRealloc)(void*,int); /* Resize an allocation */ + int (*xSize)(void*); /* Return the size of an allocation */ + int (*xRoundup)(int); /* Round up request size to allocation size */ + int (*xInit)(void*); /* Initialize the memory allocator */ + void (*xShutdown)(void*); /* Deinitialize the memory allocator */ + void *pAppData; /* Argument to xInit() and xShutdown() */ +}; + +/* +** CAPI3REF: Configuration Options +** KEYWORDS: {configuration option} +** +** These constants are the available integer configuration options that +** can be passed as the first argument to the [sqlite3_config()] interface. +** +** New configuration options may be added in future releases of SQLite. +** Existing configuration options might be discontinued. Applications +** should check the return code from [sqlite3_config()] to make sure that +** the call worked. The [sqlite3_config()] interface will return a +** non-zero [error code] if a discontinued or unsupported configuration option +** is invoked. +** +** <dl> +** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> +** <dd>There are no arguments to this option. ^This option sets the +** [threading mode] to Single-thread. In other words, it disables +** all mutexing and puts SQLite into a mode where it can only be used +** by a single thread. ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** it is not possible to change the [threading mode] from its default +** value of Single-thread and so [sqlite3_config()] will return +** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD +** configuration option.</dd> +** +** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> +** <dd>There are no arguments to this option. ^This option sets the +** [threading mode] to Multi-thread. In other words, it disables +** mutexing on [database connection] and [prepared statement] objects. +** The application is responsible for serializing access to +** [database connections] and [prepared statements]. But other mutexes +** are enabled so that SQLite will be safe to use in a multi-threaded +** environment as long as no two threads attempt to use the same +** [database connection] at the same time. ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** it is not possible to set the Multi-thread [threading mode] and +** [sqlite3_config()] will return [SQLITE_ERROR] if called with the +** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> +** +** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> +** <dd>There are no arguments to this option. ^This option sets the +** [threading mode] to Serialized. In other words, this option enables +** all mutexes including the recursive +** mutexes on [database connection] and [prepared statement] objects. +** In this mode (which is the default when SQLite is compiled with +** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access +** to [database connections] and [prepared statements] so that the +** application is free to use the same [database connection] or the +** same [prepared statement] in different threads at the same time. +** ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** it is not possible to set the Serialized [threading mode] and +** [sqlite3_config()] will return [SQLITE_ERROR] if called with the +** SQLITE_CONFIG_SERIALIZED configuration option.</dd> +** +** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> +** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is +** a pointer to an instance of the [sqlite3_mem_methods] structure. +** The argument specifies +** alternative low-level memory allocation routines to be used in place of +** the memory allocation routines built into SQLite.)^ ^SQLite makes +** its own private copy of the content of the [sqlite3_mem_methods] structure +** before the [sqlite3_config()] call returns.</dd> +** +** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> +** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which +** is a pointer to an instance of the [sqlite3_mem_methods] structure. +** The [sqlite3_mem_methods] +** structure is filled with the currently defined memory allocation routines.)^ +** This option can be used to overload the default memory allocation +** routines with a wrapper that simulations memory allocation failure or +** tracks memory usage, for example. </dd> +** +** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> +** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of +** type int, interpreted as a boolean, which if true provides a hint to +** SQLite that it should avoid large memory allocations if possible. +** SQLite will run faster if it is free to make large memory allocations, +** but some application might prefer to run slower in exchange for +** guarantees about memory fragmentation that are possible if large +** allocations are avoided. This hint is normally off. +** </dd> +** +** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> +** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, +** interpreted as a boolean, which enables or disables the collection of +** memory allocation statistics. ^(When memory allocation statistics are +** disabled, the following SQLite interfaces become non-operational: +** <ul> +** <li> [sqlite3_hard_heap_limit64()] +** <li> [sqlite3_memory_used()] +** <li> [sqlite3_memory_highwater()] +** <li> [sqlite3_soft_heap_limit64()] +** <li> [sqlite3_status64()] +** </ul>)^ +** ^Memory allocation statistics are enabled by default unless SQLite is +** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory +** allocation statistics are disabled by default. +** </dd> +** +** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> +** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. +** </dd> +** +** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> +** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool +** that SQLite can use for the database page cache with the default page +** cache implementation. +** This configuration option is a no-op if an application-defined page +** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. +** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to +** 8-byte aligned memory (pMem), the size of each page cache line (sz), +** and the number of cache lines (N). +** The sz argument should be the size of the largest database page +** (a power of two between 512 and 65536) plus some extra bytes for each +** page header. ^The number of extra bytes needed by the page header +** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. +** ^It is harmless, apart from the wasted memory, +** for the sz parameter to be larger than necessary. The pMem +** argument must be either a NULL pointer or a pointer to an 8-byte +** aligned block of memory of at least sz*N bytes, otherwise +** subsequent behavior is undefined. +** ^When pMem is not NULL, SQLite will strive to use the memory provided +** to satisfy page cache needs, falling back to [sqlite3_malloc()] if +** a page cache line is larger than sz bytes or if all of the pMem buffer +** is exhausted. +** ^If pMem is NULL and N is non-zero, then each database connection +** does an initial bulk allocation for page cache memory +** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or +** of -1024*N bytes if N is negative, . ^If additional +** page cache memory is needed beyond what is provided by the initial +** allocation, then SQLite goes to [sqlite3_malloc()] separately for each +** additional cache line. </dd> +** +** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> +** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer +** that SQLite will use for all of its dynamic memory allocation needs +** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. +** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled +** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns +** [SQLITE_ERROR] if invoked otherwise. +** ^There are three arguments to SQLITE_CONFIG_HEAP: +** An 8-byte aligned pointer to the memory, +** the number of bytes in the memory buffer, and the minimum allocation size. +** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts +** to using its default memory allocator (the system malloc() implementation), +** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the +** memory pointer is not NULL then the alternative memory +** allocator is engaged to handle all of SQLites memory allocation needs. +** The first pointer (the memory pointer) must be aligned to an 8-byte +** boundary or subsequent behavior of SQLite will be undefined. +** The minimum allocation size is capped at 2**12. Reasonable values +** for the minimum allocation size are 2**5 through 2**8.</dd> +** +** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> +** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a +** pointer to an instance of the [sqlite3_mutex_methods] structure. +** The argument specifies alternative low-level mutex routines to be used +** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of +** the content of the [sqlite3_mutex_methods] structure before the call to +** [sqlite3_config()] returns. ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** the entire mutexing subsystem is omitted from the build and hence calls to +** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will +** return [SQLITE_ERROR].</dd> +** +** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> +** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which +** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The +** [sqlite3_mutex_methods] +** structure is filled with the currently defined mutex routines.)^ +** This option can be used to overload the default mutex allocation +** routines with a wrapper used to track mutex usage for performance +** profiling or testing, for example. ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** the entire mutexing subsystem is omitted from the build and hence calls to +** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will +** return [SQLITE_ERROR].</dd> +** +** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> +** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine +** the default size of lookaside memory on each [database connection]. +** The first argument is the +** size of each lookaside buffer slot and the second is the number of +** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE +** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] +** option to [sqlite3_db_config()] can be used to change the lookaside +** configuration on individual connections.)^ </dd> +** +** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> +** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is +** a pointer to an [sqlite3_pcache_methods2] object. This object specifies +** the interface to a custom page cache implementation.)^ +** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> +** +** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> +** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which +** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of +** the current page cache implementation into that object.)^ </dd> +** +** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> +** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite +** global [error log]. +** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a +** function with a call signature of void(*)(void*,int,const char*), +** and a pointer to void. ^If the function pointer is not NULL, it is +** invoked by [sqlite3_log()] to process each logging event. ^If the +** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. +** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is +** passed through as the first parameter to the application-defined logger +** function whenever that function is invoked. ^The second parameter to +** the logger function is a copy of the first parameter to the corresponding +** [sqlite3_log()] call and is intended to be a [result code] or an +** [extended result code]. ^The third parameter passed to the logger is +** log message after formatting via [sqlite3_snprintf()]. +** The SQLite logging interface is not reentrant; the logger function +** supplied by the application must not invoke any SQLite interface. +** In a multi-threaded application, the application-defined logger +** function must be threadsafe. </dd> +** +** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI +** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. +** If non-zero, then URI handling is globally enabled. If the parameter is zero, +** then URI handling is globally disabled.)^ ^If URI handling is globally +** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], +** [sqlite3_open16()] or +** specified as part of [ATTACH] commands are interpreted as URIs, regardless +** of whether or not the [SQLITE_OPEN_URI] flag is set when the database +** connection is opened. ^If it is globally disabled, filenames are +** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the +** database connection is opened. ^(By default, URI handling is globally +** disabled. The default value may be changed by compiling with the +** [SQLITE_USE_URI] symbol defined.)^ +** +** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN +** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer +** argument which is interpreted as a boolean in order to enable or disable +** the use of covering indices for full table scans in the query optimizer. +** ^The default setting is determined +** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" +** if that compile-time option is omitted. +** The ability to disable the use of covering indices for full table scans +** is because some incorrectly coded legacy applications might malfunction +** when the optimization is enabled. Providing the ability to +** disable the optimization allows the older, buggy application code to work +** without change even with newer versions of SQLite. +** +** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] +** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE +** <dd> These options are obsolete and should not be used by new code. +** They are retained for backwards compatibility but are now no-ops. +** </dd> +** +** [[SQLITE_CONFIG_SQLLOG]] +** <dt>SQLITE_CONFIG_SQLLOG +** <dd>This option is only available if sqlite is compiled with the +** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should +** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). +** The second should be of type (void*). The callback is invoked by the library +** in three separate circumstances, identified by the value passed as the +** fourth parameter. If the fourth parameter is 0, then the database connection +** passed as the second argument has just been opened. The third argument +** points to a buffer containing the name of the main database file. If the +** fourth parameter is 1, then the SQL statement that the third parameter +** points to has just been executed. Or, if the fourth parameter is 2, then +** the connection being passed as the second parameter is being closed. The +** third parameter is passed NULL In this case. An example of using this +** configuration option can be seen in the "test_sqllog.c" source file in +** the canonical SQLite source tree.</dd> +** +** [[SQLITE_CONFIG_MMAP_SIZE]] +** <dt>SQLITE_CONFIG_MMAP_SIZE +** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values +** that are the default mmap size limit (the default setting for +** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. +** ^The default setting can be overridden by each database connection using +** either the [PRAGMA mmap_size] command, or by using the +** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size +** will be silently truncated if necessary so that it does not exceed the +** compile-time maximum mmap size set by the +** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ +** ^If either argument to this option is negative, then that argument is +** changed to its compile-time default. +** +** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] +** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE +** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is +** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro +** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value +** that specifies the maximum size of the created heap. +** +** [[SQLITE_CONFIG_PCACHE_HDRSZ]] +** <dt>SQLITE_CONFIG_PCACHE_HDRSZ +** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which +** is a pointer to an integer and writes into that integer the number of extra +** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. +** The amount of extra space required can change depending on the compiler, +** target platform, and SQLite version. +** +** [[SQLITE_CONFIG_PMASZ]] +** <dt>SQLITE_CONFIG_PMASZ +** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which +** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded +** sorter to that integer. The default minimum PMA Size is set by the +** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched +** to help with sort operations when multithreaded sorting +** is enabled (using the [PRAGMA threads] command) and the amount of content +** to be sorted exceeds the page size times the minimum of the +** [PRAGMA cache_size] setting and this value. +** +** [[SQLITE_CONFIG_STMTJRNL_SPILL]] +** <dt>SQLITE_CONFIG_STMTJRNL_SPILL +** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which +** becomes the [statement journal] spill-to-disk threshold. +** [Statement journals] are held in memory until their size (in bytes) +** exceeds this threshold, at which point they are written to disk. +** Or if the threshold is -1, statement journals are always held +** exclusively in memory. +** Since many statement journals never become large, setting the spill +** threshold to a value such as 64KiB can greatly reduce the amount of +** I/O required to support statement rollback. +** The default value for this setting is controlled by the +** [SQLITE_STMTJRNL_SPILL] compile-time option. +** +** [[SQLITE_CONFIG_SORTERREF_SIZE]] +** <dt>SQLITE_CONFIG_SORTERREF_SIZE +** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter +** of type (int) - the new value of the sorter-reference size threshold. +** Usually, when SQLite uses an external sort to order records according +** to an ORDER BY clause, all fields required by the caller are present in the +** sorted records. However, if SQLite determines based on the declared type +** of a table column that its values are likely to be very large - larger +** than the configured sorter-reference size threshold - then a reference +** is stored in each sorted record and the required column values loaded +** from the database as records are returned in sorted order. The default +** value for this option is to never use this optimization. Specifying a +** negative value for this option restores the default behaviour. +** This option is only available if SQLite is compiled with the +** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. +** +** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] +** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE +** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter +** [sqlite3_int64] parameter which is the default maximum size for an in-memory +** database created using [sqlite3_deserialize()]. This default maximum +** size can be adjusted up or down for individual databases using the +** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this +** configuration setting is never used, then the default maximum is determined +** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that +** compile-time option is not set, then the default maximum is 1073741824. +** </dl> +*/ +#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ +#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ +#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ +#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ +#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ +#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ +#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ +#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ +#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ +#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ +#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ +/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ +#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ +#define SQLITE_CONFIG_PCACHE 14 /* no-op */ +#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ +#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ +#define SQLITE_CONFIG_URI 17 /* int */ +#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ +#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ +#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ +#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ +#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ +#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ +#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ +#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ +#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ +#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ +#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ +#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ + +/* +** CAPI3REF: Database Connection Configuration Options +** +** These constants are the available integer configuration options that +** can be passed as the second argument to the [sqlite3_db_config()] interface. +** +** New configuration options may be added in future releases of SQLite. +** Existing configuration options might be discontinued. Applications +** should check the return code from [sqlite3_db_config()] to make sure that +** the call worked. ^The [sqlite3_db_config()] interface will return a +** non-zero [error code] if a discontinued or unsupported configuration option +** is invoked. +** +** <dl> +** [[SQLITE_DBCONFIG_LOOKASIDE]] +** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> +** <dd> ^This option takes three additional arguments that determine the +** [lookaside memory allocator] configuration for the [database connection]. +** ^The first argument (the third parameter to [sqlite3_db_config()] is a +** pointer to a memory buffer to use for lookaside memory. +** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb +** may be NULL in which case SQLite will allocate the +** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the +** size of each lookaside buffer slot. ^The third argument is the number of +** slots. The size of the buffer in the first argument must be greater than +** or equal to the product of the second and third arguments. The buffer +** must be aligned to an 8-byte boundary. ^If the second argument to +** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally +** rounded down to the next smaller multiple of 8. ^(The lookaside memory +** configuration for a database connection can only be changed when that +** connection is not currently using lookaside memory, or in other words +** when the "current value" returned by +** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. +** Any attempt to change the lookaside memory configuration when lookaside +** memory is in use leaves the configuration unchanged and returns +** [SQLITE_BUSY].)^</dd> +** +** [[SQLITE_DBCONFIG_ENABLE_FKEY]] +** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> +** <dd> ^This option is used to enable or disable the enforcement of +** [foreign key constraints]. There should be two additional arguments. +** The first argument is an integer which is 0 to disable FK enforcement, +** positive to enable FK enforcement or negative to leave FK enforcement +** unchanged. The second parameter is a pointer to an integer into which +** is written 0 or 1 to indicate whether FK enforcement is off or on +** following this call. The second parameter may be a NULL pointer, in +** which case the FK enforcement setting is not reported back. </dd> +** +** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] +** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> +** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. +** There should be two additional arguments. +** The first argument is an integer which is 0 to disable triggers, +** positive to enable triggers or negative to leave the setting unchanged. +** The second parameter is a pointer to an integer into which +** is written 0 or 1 to indicate whether triggers are disabled or enabled +** following this call. The second parameter may be a NULL pointer, in +** which case the trigger setting is not reported back. +** +** <p>Originally this option disabled all triggers. ^(However, since +** SQLite version 3.35.0, TEMP triggers are still allowed even if +** this option is off. So, in other words, this option now only disables +** triggers in the main database schema or in the schemas of ATTACH-ed +** databases.)^ </dd> +** +** [[SQLITE_DBCONFIG_ENABLE_VIEW]] +** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> +** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. +** There should be two additional arguments. +** The first argument is an integer which is 0 to disable views, +** positive to enable views or negative to leave the setting unchanged. +** The second parameter is a pointer to an integer into which +** is written 0 or 1 to indicate whether views are disabled or enabled +** following this call. The second parameter may be a NULL pointer, in +** which case the view setting is not reported back. +** +** <p>Originally this option disabled all views. ^(However, since +** SQLite version 3.35.0, TEMP views are still allowed even if +** this option is off. So, in other words, this option now only disables +** views in the main database schema or in the schemas of ATTACH-ed +** databases.)^ </dd> +** +** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] +** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> +** <dd> ^This option is used to enable or disable the +** [fts3_tokenizer()] function which is part of the +** [FTS3] full-text search engine extension. +** There should be two additional arguments. +** The first argument is an integer which is 0 to disable fts3_tokenizer() or +** positive to enable fts3_tokenizer() or negative to leave the setting +** unchanged. +** The second parameter is a pointer to an integer into which +** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled +** following this call. The second parameter may be a NULL pointer, in +** which case the new setting is not reported back. </dd> +** +** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] +** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> +** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] +** interface independently of the [load_extension()] SQL function. +** The [sqlite3_enable_load_extension()] API enables or disables both the +** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. +** There should be two additional arguments. +** When the first argument to this interface is 1, then only the C-API is +** enabled and the SQL function remains disabled. If the first argument to +** this interface is 0, then both the C-API and the SQL function are disabled. +** If the first argument is -1, then no changes are made to state of either the +** C-API or the SQL function. +** The second parameter is a pointer to an integer into which +** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface +** is disabled or enabled following this call. The second parameter may +** be a NULL pointer, in which case the new setting is not reported back. +** </dd> +** +** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> +** <dd> ^This option is used to change the name of the "main" database +** schema. ^The sole argument is a pointer to a constant UTF8 string +** which will become the new schema name in place of "main". ^SQLite +** does not make a copy of the new main schema name string, so the application +** must ensure that the argument passed into this DBCONFIG option is unchanged +** until after the database connection closes. +** </dd> +** +** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] +** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> +** <dd> Usually, when a database in wal mode is closed or detached from a +** database handle, SQLite checks if this will mean that there are now no +** connections at all to the database. If so, it performs a checkpoint +** operation before closing the connection. This option may be used to +** override this behaviour. The first parameter passed to this operation +** is an integer - positive to disable checkpoints-on-close, or zero (the +** default) to enable them, and negative to leave the setting unchanged. +** The second parameter is a pointer to an integer +** into which is written 0 or 1 to indicate whether checkpoints-on-close +** have been disabled - 0 if they are not disabled, 1 if they are. +** </dd> +** +** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> +** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates +** the [query planner stability guarantee] (QPSG). When the QPSG is active, +** a single SQL query statement will always use the same algorithm regardless +** of values of [bound parameters].)^ The QPSG disables some query optimizations +** that look at the values of bound parameters, which can make some queries +** slower. But the QPSG has the advantage of more predictable behavior. With +** the QPSG active, SQLite will always use the same query plan in the field as +** was used during testing in the lab. +** The first argument to this setting is an integer which is 0 to disable +** the QPSG, positive to enable QPSG, or negative to leave the setting +** unchanged. The second parameter is a pointer to an integer into which +** is written 0 or 1 to indicate whether the QPSG is disabled or enabled +** following this call. +** </dd> +** +** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> +** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not +** include output for any operations performed by trigger programs. This +** option is used to set or clear (the default) a flag that governs this +** behavior. The first parameter passed to this operation is an integer - +** positive to enable output for trigger programs, or zero to disable it, +** or negative to leave the setting unchanged. +** The second parameter is a pointer to an integer into which is written +** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if +** it is not disabled, 1 if it is. +** </dd> +** +** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> +** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run +** [VACUUM] in order to reset a database back to an empty database +** with no schema and no content. The following process works even for +** a badly corrupted database file: +** <ol> +** <li> If the database connection is newly opened, make sure it has read the +** database schema by preparing then discarding some query against the +** database, or calling sqlite3_table_column_metadata(), ignoring any +** errors. This step is only necessary if the application desires to keep +** the database in WAL mode after the reset if it was in WAL mode before +** the reset. +** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); +** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); +** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); +** </ol> +** Because resetting a database is destructive and irreversible, the +** process requires the use of this obscure API and multiple steps to help +** ensure that it does not happen by accident. +** +** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> +** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the +** "defensive" flag for a database connection. When the defensive +** flag is enabled, language features that allow ordinary SQL to +** deliberately corrupt the database file are disabled. The disabled +** features include but are not limited to the following: +** <ul> +** <li> The [PRAGMA writable_schema=ON] statement. +** <li> The [PRAGMA journal_mode=OFF] statement. +** <li> The [PRAGMA schema_version=N] statement. +** <li> Writes to the [sqlite_dbpage] virtual table. +** <li> Direct writes to [shadow tables]. +** </ul> +** </dd> +** +** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> +** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the +** "writable_schema" flag. This has the same effect and is logically equivalent +** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. +** The first argument to this setting is an integer which is 0 to disable +** the writable_schema, positive to enable writable_schema, or negative to +** leave the setting unchanged. The second parameter is a pointer to an +** integer into which is written 0 or 1 to indicate whether the writable_schema +** is enabled or disabled following this call. +** </dd> +** +** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] +** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> +** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates +** the legacy behavior of the [ALTER TABLE RENAME] command such it +** behaves as it did prior to [version 3.24.0] (2018-06-04). See the +** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for +** additional information. This feature can also be turned on and off +** using the [PRAGMA legacy_alter_table] statement. +** </dd> +** +** [[SQLITE_DBCONFIG_DQS_DML]] +** <dt>SQLITE_DBCONFIG_DQS_DML</td> +** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates +** the legacy [double-quoted string literal] misfeature for DML statements +** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The +** default value of this setting is determined by the [-DSQLITE_DQS] +** compile-time option. +** </dd> +** +** [[SQLITE_DBCONFIG_DQS_DDL]] +** <dt>SQLITE_DBCONFIG_DQS_DDL</td> +** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates +** the legacy [double-quoted string literal] misfeature for DDL statements, +** such as CREATE TABLE and CREATE INDEX. The +** default value of this setting is determined by the [-DSQLITE_DQS] +** compile-time option. +** </dd> +** +** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] +** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> +** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to +** assume that database schemas are untainted by malicious content. +** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite +** takes additional defensive steps to protect the application from harm +** including: +** <ul> +** <li> Prohibit the use of SQL functions inside triggers, views, +** CHECK constraints, DEFAULT clauses, expression indexes, +** partial indexes, or generated columns +** unless those functions are tagged with [SQLITE_INNOCUOUS]. +** <li> Prohibit the use of virtual tables inside of triggers or views +** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. +** </ul> +** This setting defaults to "on" for legacy compatibility, however +** all applications are advised to turn it off if possible. This setting +** can also be controlled using the [PRAGMA trusted_schema] statement. +** </dd> +** +** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] +** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> +** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates +** the legacy file format flag. When activated, this flag causes all newly +** created database file to have a schema format version number (the 4-byte +** integer found at offset 44 into the database header) of 1. This in turn +** means that the resulting database file will be readable and writable by +** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, +** newly created databases are generally not understandable by SQLite versions +** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there +** is now scarcely any need to generated database files that are compatible +** all the way back to version 3.0.0, and so this setting is of little +** practical use, but is provided so that SQLite can continue to claim the +** ability to generate new database files that are compatible with version +** 3.0.0. +** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, +** the [VACUUM] command will fail with an obscure error when attempting to +** process a table with generated columns and a descending index. This is +** not considered a bug since SQLite versions 3.3.0 and earlier do not support +** either generated columns or decending indexes. +** </dd> +** </dl> +*/ +#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ +#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ +#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ +#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ +#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ +#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ +#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ +#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ +#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ +#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ +#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ +#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ +#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ +#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ +#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ +#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ +#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ +#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ +#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ + +/* +** CAPI3REF: Enable Or Disable Extended Result Codes +** METHOD: sqlite3 +** +** ^The sqlite3_extended_result_codes() routine enables or disables the +** [extended result codes] feature of SQLite. ^The extended result +** codes are disabled by default for historical compatibility. +*/ +int sqlite3_extended_result_codes(sqlite3*, int onoff); + +/* +** CAPI3REF: Last Insert Rowid +** METHOD: sqlite3 +** +** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) +** has a unique 64-bit signed +** integer key called the [ROWID | "rowid"]. ^The rowid is always available +** as an undeclared column named ROWID, OID, or _ROWID_ as long as those +** names are not also used by explicitly declared columns. ^If +** the table has a column of type [INTEGER PRIMARY KEY] then that column +** is another alias for the rowid. +** +** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of +** the most recent successful [INSERT] into a rowid table or [virtual table] +** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not +** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred +** on the database connection D, then sqlite3_last_insert_rowid(D) returns +** zero. +** +** As well as being set automatically as rows are inserted into database +** tables, the value returned by this function may be set explicitly by +** [sqlite3_set_last_insert_rowid()] +** +** Some virtual table implementations may INSERT rows into rowid tables as +** part of committing a transaction (e.g. to flush data accumulated in memory +** to disk). In this case subsequent calls to this function return the rowid +** associated with these internal INSERT operations, which leads to +** unintuitive results. Virtual table implementations that do write to rowid +** tables in this way can avoid this problem by restoring the original +** rowid value using [sqlite3_set_last_insert_rowid()] before returning +** control to the user. +** +** ^(If an [INSERT] occurs within a trigger then this routine will +** return the [rowid] of the inserted row as long as the trigger is +** running. Once the trigger program ends, the value returned +** by this routine reverts to what it was before the trigger was fired.)^ +** +** ^An [INSERT] that fails due to a constraint violation is not a +** successful [INSERT] and does not change the value returned by this +** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, +** and INSERT OR ABORT make no changes to the return value of this +** routine when their insertion fails. ^(When INSERT OR REPLACE +** encounters a constraint violation, it does not fail. The +** INSERT continues to completion after deleting rows that caused +** the constraint problem so INSERT OR REPLACE will always change +** the return value of this interface.)^ +** +** ^For the purposes of this routine, an [INSERT] is considered to +** be successful even if it is subsequently rolled back. +** +** This function is accessible to SQL statements via the +** [last_insert_rowid() SQL function]. +** +** If a separate thread performs a new [INSERT] on the same +** database connection while the [sqlite3_last_insert_rowid()] +** function is running and thus changes the last insert [rowid], +** then the value returned by [sqlite3_last_insert_rowid()] is +** unpredictable and might not equal either the old or the new +** last insert [rowid]. +*/ +sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); + +/* +** CAPI3REF: Set the Last Insert Rowid value. +** METHOD: sqlite3 +** +** The sqlite3_set_last_insert_rowid(D, R) method allows the application to +** set the value returned by calling sqlite3_last_insert_rowid(D) to R +** without inserting a row into the database. +*/ +void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); + +/* +** CAPI3REF: Count The Number Of Rows Modified +** METHOD: sqlite3 +** +** ^These functions return the number of rows modified, inserted or +** deleted by the most recently completed INSERT, UPDATE or DELETE +** statement on the database connection specified by the only parameter. +** The two functions are identical except for the type of the return value +** and that if the number of rows modified by the most recent INSERT, UPDATE +** or DELETE is greater than the maximum value supported by type "int", then +** the return value of sqlite3_changes() is undefined. ^Executing any other +** type of SQL statement does not modify the value returned by these functions. +** +** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are +** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], +** [foreign key actions] or [REPLACE] constraint resolution are not counted. +** +** Changes to a view that are intercepted by +** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value +** returned by sqlite3_changes() immediately after an INSERT, UPDATE or +** DELETE statement run on a view is always zero. Only changes made to real +** tables are counted. +** +** Things are more complicated if the sqlite3_changes() function is +** executed while a trigger program is running. This may happen if the +** program uses the [changes() SQL function], or if some other callback +** function invokes sqlite3_changes() directly. Essentially: +** +** <ul> +** <li> ^(Before entering a trigger program the value returned by +** sqlite3_changes() function is saved. After the trigger program +** has finished, the original value is restored.)^ +** +** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE +** statement sets the value returned by sqlite3_changes() +** upon completion as normal. Of course, this value will not include +** any changes performed by sub-triggers, as the sqlite3_changes() +** value will be saved and restored after each sub-trigger has run.)^ +** </ul> +** +** ^This means that if the changes() SQL function (or similar) is used +** by the first INSERT, UPDATE or DELETE statement within a trigger, it +** returns the value as set when the calling statement began executing. +** ^If it is used by the second or subsequent such statement within a trigger +** program, the value returned reflects the number of rows modified by the +** previous INSERT, UPDATE or DELETE statement within the same trigger. +** +** If a separate thread makes changes on the same database connection +** while [sqlite3_changes()] is running then the value returned +** is unpredictable and not meaningful. +** +** See also: +** <ul> +** <li> the [sqlite3_total_changes()] interface +** <li> the [count_changes pragma] +** <li> the [changes() SQL function] +** <li> the [data_version pragma] +** </ul> +*/ +int sqlite3_changes(sqlite3*); +sqlite3_int64 sqlite3_changes64(sqlite3*); + +/* +** CAPI3REF: Total Number Of Rows Modified +** METHOD: sqlite3 +** +** ^These functions return the total number of rows inserted, modified or +** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed +** since the database connection was opened, including those executed as +** part of trigger programs. The two functions are identical except for the +** type of the return value and that if the number of rows modified by the +** connection exceeds the maximum value supported by type "int", then +** the return value of sqlite3_total_changes() is undefined. ^Executing +** any other type of SQL statement does not affect the value returned by +** sqlite3_total_changes(). +** +** ^Changes made as part of [foreign key actions] are included in the +** count, but those made as part of REPLACE constraint resolution are +** not. ^Changes to a view that are intercepted by INSTEAD OF triggers +** are not counted. +** +** The [sqlite3_total_changes(D)] interface only reports the number +** of rows that changed due to SQL statement run against database +** connection D. Any changes by other database connections are ignored. +** To detect changes against a database file from other database +** connections use the [PRAGMA data_version] command or the +** [SQLITE_FCNTL_DATA_VERSION] [file control]. +** +** If a separate thread makes changes on the same database connection +** while [sqlite3_total_changes()] is running then the value +** returned is unpredictable and not meaningful. +** +** See also: +** <ul> +** <li> the [sqlite3_changes()] interface +** <li> the [count_changes pragma] +** <li> the [changes() SQL function] +** <li> the [data_version pragma] +** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] +** </ul> +*/ +int sqlite3_total_changes(sqlite3*); +sqlite3_int64 sqlite3_total_changes64(sqlite3*); + +/* +** CAPI3REF: Interrupt A Long-Running Query +** METHOD: sqlite3 +** +** ^This function causes any pending database operation to abort and +** return at its earliest opportunity. This routine is typically +** called in response to a user action such as pressing "Cancel" +** or Ctrl-C where the user wants a long query operation to halt +** immediately. +** +** ^It is safe to call this routine from a thread different from the +** thread that is currently running the database operation. But it +** is not safe to call this routine with a [database connection] that +** is closed or might close before sqlite3_interrupt() returns. +** +** ^If an SQL operation is very nearly finished at the time when +** sqlite3_interrupt() is called, then it might not have an opportunity +** to be interrupted and might continue to completion. +** +** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. +** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE +** that is inside an explicit transaction, then the entire transaction +** will be rolled back automatically. +** +** ^The sqlite3_interrupt(D) call is in effect until all currently running +** SQL statements on [database connection] D complete. ^Any new SQL statements +** that are started after the sqlite3_interrupt() call and before the +** running statement count reaches zero are interrupted as if they had been +** running prior to the sqlite3_interrupt() call. ^New SQL statements +** that are started after the running statement count reaches zero are +** not effected by the sqlite3_interrupt(). +** ^A call to sqlite3_interrupt(D) that occurs when there are no running +** SQL statements is a no-op and has no effect on SQL statements +** that are started after the sqlite3_interrupt() call returns. +*/ +void sqlite3_interrupt(sqlite3*); + +/* +** CAPI3REF: Determine If An SQL Statement Is Complete +** +** These routines are useful during command-line input to determine if the +** currently entered text seems to form a complete SQL statement or +** if additional input is needed before sending the text into +** SQLite for parsing. ^These routines return 1 if the input string +** appears to be a complete SQL statement. ^A statement is judged to be +** complete if it ends with a semicolon token and is not a prefix of a +** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within +** string literals or quoted identifier names or comments are not +** independent tokens (they are part of the token in which they are +** embedded) and thus do not count as a statement terminator. ^Whitespace +** and comments that follow the final semicolon are ignored. +** +** ^These routines return 0 if the statement is incomplete. ^If a +** memory allocation fails, then SQLITE_NOMEM is returned. +** +** ^These routines do not parse the SQL statements thus +** will not detect syntactically incorrect SQL. +** +** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior +** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked +** automatically by sqlite3_complete16(). If that initialization fails, +** then the return value from sqlite3_complete16() will be non-zero +** regardless of whether or not the input SQL is complete.)^ +** +** The input to [sqlite3_complete()] must be a zero-terminated +** UTF-8 string. +** +** The input to [sqlite3_complete16()] must be a zero-terminated +** UTF-16 string in native byte order. +*/ +int sqlite3_complete(const char *sql); +int sqlite3_complete16(const void *sql); + +/* +** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors +** KEYWORDS: {busy-handler callback} {busy handler} +** METHOD: sqlite3 +** +** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X +** that might be invoked with argument P whenever +** an attempt is made to access a database table associated with +** [database connection] D when another thread +** or process has the table locked. +** The sqlite3_busy_handler() interface is used to implement +** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. +** +** ^If the busy callback is NULL, then [SQLITE_BUSY] +** is returned immediately upon encountering the lock. ^If the busy callback +** is not NULL, then the callback might be invoked with two arguments. +** +** ^The first argument to the busy handler is a copy of the void* pointer which +** is the third argument to sqlite3_busy_handler(). ^The second argument to +** the busy handler callback is the number of times that the busy handler has +** been invoked previously for the same locking event. ^If the +** busy callback returns 0, then no additional attempts are made to +** access the database and [SQLITE_BUSY] is returned +** to the application. +** ^If the callback returns non-zero, then another attempt +** is made to access the database and the cycle repeats. +** +** The presence of a busy handler does not guarantee that it will be invoked +** when there is lock contention. ^If SQLite determines that invoking the busy +** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] +** to the application instead of invoking the +** busy handler. +** Consider a scenario where one process is holding a read lock that +** it is trying to promote to a reserved lock and +** a second process is holding a reserved lock that it is trying +** to promote to an exclusive lock. The first process cannot proceed +** because it is blocked by the second and the second process cannot +** proceed because it is blocked by the first. If both processes +** invoke the busy handlers, neither will make any progress. Therefore, +** SQLite returns [SQLITE_BUSY] for the first process, hoping that this +** will induce the first process to release its read lock and allow +** the second process to proceed. +** +** ^The default busy callback is NULL. +** +** ^(There can only be a single busy handler defined for each +** [database connection]. Setting a new busy handler clears any +** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] +** or evaluating [PRAGMA busy_timeout=N] will change the +** busy handler and thus clear any previously set busy handler. +** +** The busy callback should not take any actions which modify the +** database connection that invoked the busy handler. In other words, +** the busy handler is not reentrant. Any such actions +** result in undefined behavior. +** +** A busy handler must not close the database connection +** or [prepared statement] that invoked the busy handler. +*/ +int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); + +/* +** CAPI3REF: Set A Busy Timeout +** METHOD: sqlite3 +** +** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps +** for a specified amount of time when a table is locked. ^The handler +** will sleep multiple times until at least "ms" milliseconds of sleeping +** have accumulated. ^After at least "ms" milliseconds of sleeping, +** the handler returns 0 which causes [sqlite3_step()] to return +** [SQLITE_BUSY]. +** +** ^Calling this routine with an argument less than or equal to zero +** turns off all busy handlers. +** +** ^(There can only be a single busy handler for a particular +** [database connection] at any given moment. If another busy handler +** was defined (using [sqlite3_busy_handler()]) prior to calling +** this routine, that other busy handler is cleared.)^ +** +** See also: [PRAGMA busy_timeout] +*/ +int sqlite3_busy_timeout(sqlite3*, int ms); + +/* +** CAPI3REF: Convenience Routines For Running Queries +** METHOD: sqlite3 +** +** This is a legacy interface that is preserved for backwards compatibility. +** Use of this interface is not recommended. +** +** Definition: A <b>result table</b> is memory data structure created by the +** [sqlite3_get_table()] interface. A result table records the +** complete query results from one or more queries. +** +** The table conceptually has a number of rows and columns. But +** these numbers are not part of the result table itself. These +** numbers are obtained separately. Let N be the number of rows +** and M be the number of columns. +** +** A result table is an array of pointers to zero-terminated UTF-8 strings. +** There are (N+1)*M elements in the array. The first M pointers point +** to zero-terminated strings that contain the names of the columns. +** The remaining entries all point to query results. NULL values result +** in NULL pointers. All other values are in their UTF-8 zero-terminated +** string representation as returned by [sqlite3_column_text()]. +** +** A result table might consist of one or more memory allocations. +** It is not safe to pass a result table directly to [sqlite3_free()]. +** A result table should be deallocated using [sqlite3_free_table()]. +** +** ^(As an example of the result table format, suppose a query result +** is as follows: +** +** <blockquote><pre> +** Name | Age +** ----------------------- +** Alice | 43 +** Bob | 28 +** Cindy | 21 +** </pre></blockquote> +** +** There are two columns (M==2) and three rows (N==3). Thus the +** result table has 8 entries. Suppose the result table is stored +** in an array named azResult. Then azResult holds this content: +** +** <blockquote><pre> +** azResult[0] = "Name"; +** azResult[1] = "Age"; +** azResult[2] = "Alice"; +** azResult[3] = "43"; +** azResult[4] = "Bob"; +** azResult[5] = "28"; +** azResult[6] = "Cindy"; +** azResult[7] = "21"; +** </pre></blockquote>)^ +** +** ^The sqlite3_get_table() function evaluates one or more +** semicolon-separated SQL statements in the zero-terminated UTF-8 +** string of its 2nd parameter and returns a result table to the +** pointer given in its 3rd parameter. +** +** After the application has finished with the result from sqlite3_get_table(), +** it must pass the result table pointer to sqlite3_free_table() in order to +** release the memory that was malloced. Because of the way the +** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling +** function must not try to call [sqlite3_free()] directly. Only +** [sqlite3_free_table()] is able to release the memory properly and safely. +** +** The sqlite3_get_table() interface is implemented as a wrapper around +** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access +** to any internal data structures of SQLite. It uses only the public +** interface defined here. As a consequence, errors that occur in the +** wrapper layer outside of the internal [sqlite3_exec()] call are not +** reflected in subsequent calls to [sqlite3_errcode()] or +** [sqlite3_errmsg()]. +*/ +int sqlite3_get_table( + sqlite3 *db, /* An open database */ + const char *zSql, /* SQL to be evaluated */ + char ***pazResult, /* Results of the query */ + int *pnRow, /* Number of result rows written here */ + int *pnColumn, /* Number of result columns written here */ + char **pzErrmsg /* Error msg written here */ +); +void sqlite3_free_table(char **result); + +/* +** CAPI3REF: Formatted String Printing Functions +** +** These routines are work-alikes of the "printf()" family of functions +** from the standard C library. +** These routines understand most of the common formatting options from +** the standard library printf() +** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). +** See the [built-in printf()] documentation for details. +** +** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their +** results into memory obtained from [sqlite3_malloc64()]. +** The strings returned by these two routines should be +** released by [sqlite3_free()]. ^Both routines return a +** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough +** memory to hold the resulting string. +** +** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from +** the standard C library. The result is written into the +** buffer supplied as the second parameter whose size is given by +** the first parameter. Note that the order of the +** first two parameters is reversed from snprintf().)^ This is an +** historical accident that cannot be fixed without breaking +** backwards compatibility. ^(Note also that sqlite3_snprintf() +** returns a pointer to its buffer instead of the number of +** characters actually written into the buffer.)^ We admit that +** the number of characters written would be a more useful return +** value but we cannot change the implementation of sqlite3_snprintf() +** now without breaking compatibility. +** +** ^As long as the buffer size is greater than zero, sqlite3_snprintf() +** guarantees that the buffer is always zero-terminated. ^The first +** parameter "n" is the total size of the buffer, including space for +** the zero terminator. So the longest string that can be completely +** written will be n-1 characters. +** +** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). +** +** See also: [built-in printf()], [printf() SQL function] +*/ +char *sqlite3_mprintf(const char*,...); +char *sqlite3_vmprintf(const char*, va_list); +char *sqlite3_snprintf(int,char*,const char*, ...); +char *sqlite3_vsnprintf(int,char*,const char*, va_list); + +/* +** CAPI3REF: Memory Allocation Subsystem +** +** The SQLite core uses these three routines for all of its own +** internal memory allocation needs. "Core" in the previous sentence +** does not include operating-system specific [VFS] implementation. The +** Windows VFS uses native malloc() and free() for some operations. +** +** ^The sqlite3_malloc() routine returns a pointer to a block +** of memory at least N bytes in length, where N is the parameter. +** ^If sqlite3_malloc() is unable to obtain sufficient free +** memory, it returns a NULL pointer. ^If the parameter N to +** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns +** a NULL pointer. +** +** ^The sqlite3_malloc64(N) routine works just like +** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead +** of a signed 32-bit integer. +** +** ^Calling sqlite3_free() with a pointer previously returned +** by sqlite3_malloc() or sqlite3_realloc() releases that memory so +** that it might be reused. ^The sqlite3_free() routine is +** a no-op if is called with a NULL pointer. Passing a NULL pointer +** to sqlite3_free() is harmless. After being freed, memory +** should neither be read nor written. Even reading previously freed +** memory might result in a segmentation fault or other severe error. +** Memory corruption, a segmentation fault, or other severe error +** might result if sqlite3_free() is called with a non-NULL pointer that +** was not obtained from sqlite3_malloc() or sqlite3_realloc(). +** +** ^The sqlite3_realloc(X,N) interface attempts to resize a +** prior memory allocation X to be at least N bytes. +** ^If the X parameter to sqlite3_realloc(X,N) +** is a NULL pointer then its behavior is identical to calling +** sqlite3_malloc(N). +** ^If the N parameter to sqlite3_realloc(X,N) is zero or +** negative then the behavior is exactly the same as calling +** sqlite3_free(X). +** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation +** of at least N bytes in size or NULL if insufficient memory is available. +** ^If M is the size of the prior allocation, then min(N,M) bytes +** of the prior allocation are copied into the beginning of buffer returned +** by sqlite3_realloc(X,N) and the prior allocation is freed. +** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the +** prior allocation is not freed. +** +** ^The sqlite3_realloc64(X,N) interfaces works the same as +** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead +** of a 32-bit signed integer. +** +** ^If X is a memory allocation previously obtained from sqlite3_malloc(), +** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then +** sqlite3_msize(X) returns the size of that memory allocation in bytes. +** ^The value returned by sqlite3_msize(X) might be larger than the number +** of bytes requested when X was allocated. ^If X is a NULL pointer then +** sqlite3_msize(X) returns zero. If X points to something that is not +** the beginning of memory allocation, or if it points to a formerly +** valid memory allocation that has now been freed, then the behavior +** of sqlite3_msize(X) is undefined and possibly harmful. +** +** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), +** sqlite3_malloc64(), and sqlite3_realloc64() +** is always aligned to at least an 8 byte boundary, or to a +** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time +** option is used. +** +** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] +** must be either NULL or else pointers obtained from a prior +** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have +** not yet been released. +** +** The application must not read or write any part of +** a block of memory after it has been released using +** [sqlite3_free()] or [sqlite3_realloc()]. +*/ +void *sqlite3_malloc(int); +void *sqlite3_malloc64(sqlite3_uint64); +void *sqlite3_realloc(void*, int); +void *sqlite3_realloc64(void*, sqlite3_uint64); +void sqlite3_free(void*); +sqlite3_uint64 sqlite3_msize(void*); + +/* +** CAPI3REF: Memory Allocator Statistics +** +** SQLite provides these two interfaces for reporting on the status +** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] +** routines, which form the built-in memory allocation subsystem. +** +** ^The [sqlite3_memory_used()] routine returns the number of bytes +** of memory currently outstanding (malloced but not freed). +** ^The [sqlite3_memory_highwater()] routine returns the maximum +** value of [sqlite3_memory_used()] since the high-water mark +** was last reset. ^The values returned by [sqlite3_memory_used()] and +** [sqlite3_memory_highwater()] include any overhead +** added by SQLite in its implementation of [sqlite3_malloc()], +** but not overhead added by the any underlying system library +** routines that [sqlite3_malloc()] may call. +** +** ^The memory high-water mark is reset to the current value of +** [sqlite3_memory_used()] if and only if the parameter to +** [sqlite3_memory_highwater()] is true. ^The value returned +** by [sqlite3_memory_highwater(1)] is the high-water mark +** prior to the reset. +*/ +sqlite3_int64 sqlite3_memory_used(void); +sqlite3_int64 sqlite3_memory_highwater(int resetFlag); + +/* +** CAPI3REF: Pseudo-Random Number Generator +** +** SQLite contains a high-quality pseudo-random number generator (PRNG) used to +** select random [ROWID | ROWIDs] when inserting new records into a table that +** already uses the largest possible [ROWID]. The PRNG is also used for +** the built-in random() and randomblob() SQL functions. This interface allows +** applications to access the same PRNG for other purposes. +** +** ^A call to this routine stores N bytes of randomness into buffer P. +** ^The P parameter can be a NULL pointer. +** +** ^If this routine has not been previously called or if the previous +** call had N less than one or a NULL pointer for P, then the PRNG is +** seeded using randomness obtained from the xRandomness method of +** the default [sqlite3_vfs] object. +** ^If the previous call to this routine had an N of 1 or more and a +** non-NULL P then the pseudo-randomness is generated +** internally and without recourse to the [sqlite3_vfs] xRandomness +** method. +*/ +void sqlite3_randomness(int N, void *P); + +/* +** CAPI3REF: Compile-Time Authorization Callbacks +** METHOD: sqlite3 +** KEYWORDS: {authorizer callback} +** +** ^This routine registers an authorizer callback with a particular +** [database connection], supplied in the first argument. +** ^The authorizer callback is invoked as SQL statements are being compiled +** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], +** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], +** and [sqlite3_prepare16_v3()]. ^At various +** points during the compilation process, as logic is being created +** to perform various actions, the authorizer callback is invoked to +** see if those actions are allowed. ^The authorizer callback should +** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the +** specific action but allow the SQL statement to continue to be +** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be +** rejected with an error. ^If the authorizer callback returns +** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] +** then the [sqlite3_prepare_v2()] or equivalent call that triggered +** the authorizer will fail with an error message. +** +** When the callback returns [SQLITE_OK], that means the operation +** requested is ok. ^When the callback returns [SQLITE_DENY], the +** [sqlite3_prepare_v2()] or equivalent call that triggered the +** authorizer will fail with an error message explaining that +** access is denied. +** +** ^The first parameter to the authorizer callback is a copy of the third +** parameter to the sqlite3_set_authorizer() interface. ^The second parameter +** to the callback is an integer [SQLITE_COPY | action code] that specifies +** the particular action to be authorized. ^The third through sixth parameters +** to the callback are either NULL pointers or zero-terminated strings +** that contain additional details about the action to be authorized. +** Applications must always be prepared to encounter a NULL pointer in any +** of the third through the sixth parameters of the authorization callback. +** +** ^If the action code is [SQLITE_READ] +** and the callback returns [SQLITE_IGNORE] then the +** [prepared statement] statement is constructed to substitute +** a NULL value in place of the table column that would have +** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] +** return can be used to deny an untrusted user access to individual +** columns of a table. +** ^When a table is referenced by a [SELECT] but no column values are +** extracted from that table (for example in a query like +** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback +** is invoked once for that table with a column name that is an empty string. +** ^If the action code is [SQLITE_DELETE] and the callback returns +** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the +** [truncate optimization] is disabled and all rows are deleted individually. +** +** An authorizer is used when [sqlite3_prepare | preparing] +** SQL statements from an untrusted source, to ensure that the SQL statements +** do not try to access data they are not allowed to see, or that they do not +** try to execute malicious statements that damage the database. For +** example, an application may allow a user to enter arbitrary +** SQL queries for evaluation by a database. But the application does +** not want the user to be able to make arbitrary changes to the +** database. An authorizer could then be put in place while the +** user-entered SQL is being [sqlite3_prepare | prepared] that +** disallows everything except [SELECT] statements. +** +** Applications that need to process SQL from untrusted sources +** might also consider lowering resource limits using [sqlite3_limit()] +** and limiting database size using the [max_page_count] [PRAGMA] +** in addition to using an authorizer. +** +** ^(Only a single authorizer can be in place on a database connection +** at a time. Each call to sqlite3_set_authorizer overrides the +** previous call.)^ ^Disable the authorizer by installing a NULL callback. +** The authorizer is disabled by default. +** +** The authorizer callback must not do anything that will modify +** the database connection that invoked the authorizer callback. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the +** statement might be re-prepared during [sqlite3_step()] due to a +** schema change. Hence, the application should ensure that the +** correct authorizer callback remains in place during the [sqlite3_step()]. +** +** ^Note that the authorizer callback is invoked only during +** [sqlite3_prepare()] or its variants. Authorization is not +** performed during statement evaluation in [sqlite3_step()], unless +** as stated in the previous paragraph, sqlite3_step() invokes +** sqlite3_prepare_v2() to reprepare a statement after a schema change. +*/ +int sqlite3_set_authorizer( + sqlite3*, + int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), + void *pUserData +); + +/* +** CAPI3REF: Authorizer Return Codes +** +** The [sqlite3_set_authorizer | authorizer callback function] must +** return either [SQLITE_OK] or one of these two constants in order +** to signal SQLite whether or not the action is permitted. See the +** [sqlite3_set_authorizer | authorizer documentation] for additional +** information. +** +** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] +** returned from the [sqlite3_vtab_on_conflict()] interface. +*/ +#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ +#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ + +/* +** CAPI3REF: Authorizer Action Codes +** +** The [sqlite3_set_authorizer()] interface registers a callback function +** that is invoked to authorize certain SQL statement actions. The +** second parameter to the callback is an integer code that specifies +** what action is being authorized. These are the integer action codes that +** the authorizer callback may be passed. +** +** These action code values signify what kind of operation is to be +** authorized. The 3rd and 4th parameters to the authorization +** callback function will be parameters or NULL depending on which of these +** codes is used as the second parameter. ^(The 5th parameter to the +** authorizer callback is the name of the database ("main", "temp", +** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback +** is the name of the inner-most trigger or view that is responsible for +** the access attempt or NULL if this access attempt is directly from +** top-level SQL code. +*/ +/******************************************* 3rd ************ 4th ***********/ +#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ +#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ +#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ +#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ +#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ +#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ +#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ +#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ +#define SQLITE_DELETE 9 /* Table Name NULL */ +#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ +#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ +#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ +#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ +#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ +#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ +#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ +#define SQLITE_DROP_VIEW 17 /* View Name NULL */ +#define SQLITE_INSERT 18 /* Table Name NULL */ +#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ +#define SQLITE_READ 20 /* Table Name Column Name */ +#define SQLITE_SELECT 21 /* NULL NULL */ +#define SQLITE_TRANSACTION 22 /* Operation NULL */ +#define SQLITE_UPDATE 23 /* Table Name Column Name */ +#define SQLITE_ATTACH 24 /* Filename NULL */ +#define SQLITE_DETACH 25 /* Database Name NULL */ +#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ +#define SQLITE_REINDEX 27 /* Index Name NULL */ +#define SQLITE_ANALYZE 28 /* Table Name NULL */ +#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ +#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ +#define SQLITE_FUNCTION 31 /* NULL Function Name */ +#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ +#define SQLITE_COPY 0 /* No longer used */ +#define SQLITE_RECURSIVE 33 /* NULL NULL */ + +/* +** CAPI3REF: Tracing And Profiling Functions +** METHOD: sqlite3 +** +** These routines are deprecated. Use the [sqlite3_trace_v2()] interface +** instead of the routines described here. +** +** These routines register callback functions that can be used for +** tracing and profiling the execution of SQL statements. +** +** ^The callback function registered by sqlite3_trace() is invoked at +** various times when an SQL statement is being run by [sqlite3_step()]. +** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the +** SQL statement text as the statement first begins executing. +** ^(Additional sqlite3_trace() callbacks might occur +** as each triggered subprogram is entered. The callbacks for triggers +** contain a UTF-8 SQL comment that identifies the trigger.)^ +** +** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit +** the length of [bound parameter] expansion in the output of sqlite3_trace(). +** +** ^The callback function registered by sqlite3_profile() is invoked +** as each SQL statement finishes. ^The profile callback contains +** the original statement text and an estimate of wall-clock time +** of how long that statement took to run. ^The profile callback +** time is in units of nanoseconds, however the current implementation +** is only capable of millisecond resolution so the six least significant +** digits in the time are meaningless. Future versions of SQLite +** might provide greater resolution on the profiler callback. Invoking +** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the +** profile callback. +*/ +SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, + void(*xTrace)(void*,const char*), void*); +SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, + void(*xProfile)(void*,const char*,sqlite3_uint64), void*); + +/* +** CAPI3REF: SQL Trace Event Codes +** KEYWORDS: SQLITE_TRACE +** +** These constants identify classes of events that can be monitored +** using the [sqlite3_trace_v2()] tracing logic. The M argument +** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of +** the following constants. ^The first argument to the trace callback +** is one of the following constants. +** +** New tracing constants may be added in future releases. +** +** ^A trace callback has four arguments: xCallback(T,C,P,X). +** ^The T argument is one of the integer type codes above. +** ^The C argument is a copy of the context pointer passed in as the +** fourth argument to [sqlite3_trace_v2()]. +** The P and X arguments are pointers whose meanings depend on T. +** +** <dl> +** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> +** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement +** first begins running and possibly at other times during the +** execution of the prepared statement, such as at the start of each +** trigger subprogram. ^The P argument is a pointer to the +** [prepared statement]. ^The X argument is a pointer to a string which +** is the unexpanded SQL text of the prepared statement or an SQL comment +** that indicates the invocation of a trigger. ^The callback can compute +** the same text that would have been returned by the legacy [sqlite3_trace()] +** interface by using the X argument when X begins with "--" and invoking +** [sqlite3_expanded_sql(P)] otherwise. +** +** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> +** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same +** information as is provided by the [sqlite3_profile()] callback. +** ^The P argument is a pointer to the [prepared statement] and the +** X argument points to a 64-bit integer which is the estimated of +** the number of nanosecond that the prepared statement took to run. +** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. +** +** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> +** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared +** statement generates a single row of result. +** ^The P argument is a pointer to the [prepared statement] and the +** X argument is unused. +** +** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> +** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database +** connection closes. +** ^The P argument is a pointer to the [database connection] object +** and the X argument is unused. +** </dl> +*/ +#define SQLITE_TRACE_STMT 0x01 +#define SQLITE_TRACE_PROFILE 0x02 +#define SQLITE_TRACE_ROW 0x04 +#define SQLITE_TRACE_CLOSE 0x08 + +/* +** CAPI3REF: SQL Trace Hook +** METHOD: sqlite3 +** +** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback +** function X against [database connection] D, using property mask M +** and context pointer P. ^If the X callback is +** NULL or if the M mask is zero, then tracing is disabled. The +** M argument should be the bitwise OR-ed combination of +** zero or more [SQLITE_TRACE] constants. +** +** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides +** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). +** +** ^The X callback is invoked whenever any of the events identified by +** mask M occur. ^The integer return value from the callback is currently +** ignored, though this may change in future releases. Callback +** implementations should return zero to ensure future compatibility. +** +** ^A trace callback is invoked with four arguments: callback(T,C,P,X). +** ^The T argument is one of the [SQLITE_TRACE] +** constants to indicate why the callback was invoked. +** ^The C argument is a copy of the context pointer. +** The P and X arguments are pointers whose meanings depend on T. +** +** The sqlite3_trace_v2() interface is intended to replace the legacy +** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which +** are deprecated. +*/ +int sqlite3_trace_v2( + sqlite3*, + unsigned uMask, + int(*xCallback)(unsigned,void*,void*,void*), + void *pCtx +); + +/* +** CAPI3REF: Query Progress Callbacks +** METHOD: sqlite3 +** +** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback +** function X to be invoked periodically during long running calls to +** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for +** database connection D. An example use for this +** interface is to keep a GUI updated during a large query. +** +** ^The parameter P is passed through as the only parameter to the +** callback function X. ^The parameter N is the approximate number of +** [virtual machine instructions] that are evaluated between successive +** invocations of the callback X. ^If N is less than one then the progress +** handler is disabled. +** +** ^Only a single progress handler may be defined at one time per +** [database connection]; setting a new progress handler cancels the +** old one. ^Setting parameter X to NULL disables the progress handler. +** ^The progress handler is also disabled by setting N to a value less +** than 1. +** +** ^If the progress callback returns non-zero, the operation is +** interrupted. This feature can be used to implement a +** "Cancel" button on a GUI progress dialog box. +** +** The progress handler callback must not do anything that will modify +** the database connection that invoked the progress handler. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +*/ +void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); + +/* +** CAPI3REF: Opening A New Database Connection +** CONSTRUCTOR: sqlite3 +** +** ^These routines open an SQLite database file as specified by the +** filename argument. ^The filename argument is interpreted as UTF-8 for +** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte +** order for sqlite3_open16(). ^(A [database connection] handle is usually +** returned in *ppDb, even if an error occurs. The only exception is that +** if SQLite is unable to allocate memory to hold the [sqlite3] object, +** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] +** object.)^ ^(If the database is opened (and/or created) successfully, then +** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The +** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain +** an English language description of the error following a failure of any +** of the sqlite3_open() routines. +** +** ^The default encoding will be UTF-8 for databases created using +** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases +** created using sqlite3_open16() will be UTF-16 in the native byte order. +** +** Whether or not an error occurs when it is opened, resources +** associated with the [database connection] handle should be released by +** passing it to [sqlite3_close()] when it is no longer required. +** +** The sqlite3_open_v2() interface works like sqlite3_open() +** except that it accepts two additional parameters for additional control +** over the new database connection. ^(The flags parameter to +** sqlite3_open_v2() must include, at a minimum, one of the following +** three flag combinations:)^ +** +** <dl> +** ^(<dt>[SQLITE_OPEN_READONLY]</dt> +** <dd>The database is opened in read-only mode. If the database does not +** already exist, an error is returned.</dd>)^ +** +** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> +** <dd>The database is opened for reading and writing if possible, or reading +** only if the file is write protected by the operating system. In either +** case the database must already exist, otherwise an error is returned.</dd>)^ +** +** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> +** <dd>The database is opened for reading and writing, and is created if +** it does not already exist. This is the behavior that is always used for +** sqlite3_open() and sqlite3_open16().</dd>)^ +** </dl> +** +** In addition to the required flags, the following optional flags are +** also supported: +** +** <dl> +** ^(<dt>[SQLITE_OPEN_URI]</dt> +** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ +** +** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> +** <dd>The database will be opened as an in-memory database. The database +** is named by the "filename" argument for the purposes of cache-sharing, +** if shared cache mode is enabled, but the "filename" is otherwise ignored. +** </dd>)^ +** +** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> +** <dd>The new database connection will use the "multi-thread" +** [threading mode].)^ This means that separate threads are allowed +** to use SQLite at the same time, as long as each thread is using +** a different [database connection]. +** +** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> +** <dd>The new database connection will use the "serialized" +** [threading mode].)^ This means the multiple threads can safely +** attempt to use the same database connection at the same time. +** (Mutexes will block any actual concurrency, but in this mode +** there is no harm in trying.) +** +** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> +** <dd>The database is opened [shared cache] enabled, overriding +** the default shared cache setting provided by +** [sqlite3_enable_shared_cache()].)^ +** The [use of shared cache mode is discouraged] and hence shared cache +** capabilities may be omitted from many builds of SQLite. In such cases, +** this option is a no-op. +** +** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> +** <dd>The database is opened [shared cache] disabled, overriding +** the default shared cache setting provided by +** [sqlite3_enable_shared_cache()].)^ +** +** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> +** <dd>The database connection comes up in "extended result code mode". +** In other words, the database behaves has if +** [sqlite3_extended_result_codes(db,1)] where called on the database +** connection as soon as the connection is created. In addition to setting +** the extended result code mode, this flag also causes [sqlite3_open_v2()] +** to return an extended result code.</dd> +** +** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> +** <dd>The database filename is not allowed to contain a symbolic link</dd> +** </dl>)^ +** +** If the 3rd parameter to sqlite3_open_v2() is not one of the +** required combinations shown above optionally combined with other +** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] +** then the behavior is undefined. Historic versions of SQLite +** have silently ignored surplus bits in the flags parameter to +** sqlite3_open_v2(), however that behavior might not be carried through +** into future versions of SQLite and so applications should not rely +** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op +** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause +** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE +** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not +** by sqlite3_open_v2(). +** +** ^The fourth parameter to sqlite3_open_v2() is the name of the +** [sqlite3_vfs] object that defines the operating system interface that +** the new database connection should use. ^If the fourth parameter is +** a NULL pointer then the default [sqlite3_vfs] object is used. +** +** ^If the filename is ":memory:", then a private, temporary in-memory database +** is created for the connection. ^This in-memory database will vanish when +** the database connection is closed. Future versions of SQLite might +** make use of additional special filenames that begin with the ":" character. +** It is recommended that when a database filename actually does begin with +** a ":" character you should prefix the filename with a pathname such as +** "./" to avoid ambiguity. +** +** ^If the filename is an empty string, then a private, temporary +** on-disk database will be created. ^This private database will be +** automatically deleted as soon as the database connection is closed. +** +** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> +** +** ^If [URI filename] interpretation is enabled, and the filename argument +** begins with "file:", then the filename is interpreted as a URI. ^URI +** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is +** set in the third argument to sqlite3_open_v2(), or if it has +** been enabled globally using the [SQLITE_CONFIG_URI] option with the +** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. +** URI filename interpretation is turned off +** by default, but future releases of SQLite might enable URI filename +** interpretation by default. See "[URI filenames]" for additional +** information. +** +** URI filenames are parsed according to RFC 3986. ^If the URI contains an +** authority, then it must be either an empty string or the string +** "localhost". ^If the authority is not an empty string or "localhost", an +** error is returned to the caller. ^The fragment component of a URI, if +** present, is ignored. +** +** ^SQLite uses the path component of the URI as the name of the disk file +** which contains the database. ^If the path begins with a '/' character, +** then it is interpreted as an absolute path. ^If the path does not begin +** with a '/' (meaning that the authority section is omitted from the URI) +** then the path is interpreted as a relative path. +** ^(On windows, the first component of an absolute path +** is a drive specification (e.g. "C:").)^ +** +** [[core URI query parameters]] +** The query component of a URI may contain parameters that are interpreted +** either by SQLite itself, or by a [VFS | custom VFS implementation]. +** SQLite and its built-in [VFSes] interpret the +** following query parameters: +** +** <ul> +** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of +** a VFS object that provides the operating system interface that should +** be used to access the database file on disk. ^If this option is set to +** an empty string the default VFS object is used. ^Specifying an unknown +** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is +** present, then the VFS specified by the option takes precedence over +** the value passed as the fourth parameter to sqlite3_open_v2(). +** +** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", +** "rwc", or "memory". Attempting to set it to any other value is +** an error)^. +** ^If "ro" is specified, then the database is opened for read-only +** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the +** third argument to sqlite3_open_v2(). ^If the mode option is set to +** "rw", then the database is opened for read-write (but not create) +** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had +** been set. ^Value "rwc" is equivalent to setting both +** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is +** set to "memory" then a pure [in-memory database] that never reads +** or writes from disk is used. ^It is an error to specify a value for +** the mode parameter that is less restrictive than that specified by +** the flags passed in the third parameter to sqlite3_open_v2(). +** +** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or +** "private". ^Setting it to "shared" is equivalent to setting the +** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to +** sqlite3_open_v2(). ^Setting the cache parameter to "private" is +** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. +** ^If sqlite3_open_v2() is used and the "cache" parameter is present in +** a URI filename, its value overrides any behavior requested by setting +** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. +** +** <li> <b>psow</b>: ^The psow parameter indicates whether or not the +** [powersafe overwrite] property does or does not apply to the +** storage media on which the database file resides. +** +** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter +** which if set disables file locking in rollback journal modes. This +** is useful for accessing a database on a filesystem that does not +** support locking. Caution: Database corruption might result if two +** or more processes write to the same database and any one of those +** processes uses nolock=1. +** +** <li> <b>immutable</b>: ^The immutable parameter is a boolean query +** parameter that indicates that the database file is stored on +** read-only media. ^When immutable is set, SQLite assumes that the +** database file cannot be changed, even by a process with higher +** privilege, and so the database is opened read-only and all locking +** and change detection is disabled. Caution: Setting the immutable +** property on a database file that does in fact change can result +** in incorrect query results and/or [SQLITE_CORRUPT] errors. +** See also: [SQLITE_IOCAP_IMMUTABLE]. +** +** </ul> +** +** ^Specifying an unknown parameter in the query component of a URI is not an +** error. Future versions of SQLite might understand additional query +** parameters. See "[query parameters with special meaning to SQLite]" for +** additional information. +** +** [[URI filename examples]] <h3>URI filename examples</h3> +** +** <table border="1" align=center cellpadding=5> +** <tr><th> URI filenames <th> Results +** <tr><td> file:data.db <td> +** Open the file "data.db" in the current directory. +** <tr><td> file:/home/fred/data.db<br> +** file:///home/fred/data.db <br> +** file://localhost/home/fred/data.db <br> <td> +** Open the database file "/home/fred/data.db". +** <tr><td> file://darkstar/home/fred/data.db <td> +** An error. "darkstar" is not a recognized authority. +** <tr><td style="white-space:nowrap"> +** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db +** <td> Windows only: Open the file "data.db" on fred's desktop on drive +** C:. Note that the %20 escaping in this example is not strictly +** necessary - space characters can be used literally +** in URI filenames. +** <tr><td> file:data.db?mode=ro&cache=private <td> +** Open file "data.db" in the current directory for read-only access. +** Regardless of whether or not shared-cache mode is enabled by +** default, use a private cache. +** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> +** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" +** that uses dot-files in place of posix advisory locking. +** <tr><td> file:data.db?mode=readonly <td> +** An error. "readonly" is not a valid option for the "mode" parameter. +** Use "ro" instead: "file:data.db?mode=ro". +** </table> +** +** ^URI hexadecimal escape sequences (%HH) are supported within the path and +** query components of a URI. A hexadecimal escape sequence consists of a +** percent sign - "%" - followed by exactly two hexadecimal digits +** specifying an octet value. ^Before the path or query components of a +** URI filename are interpreted, they are encoded using UTF-8 and all +** hexadecimal escape sequences replaced by a single byte containing the +** corresponding octet. If this process generates an invalid UTF-8 encoding, +** the results are undefined. +** +** <b>Note to Windows users:</b> The encoding used for the filename argument +** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever +** codepage is currently defined. Filenames containing international +** characters must be converted to UTF-8 prior to passing them into +** sqlite3_open() or sqlite3_open_v2(). +** +** <b>Note to Windows Runtime users:</b> The temporary directory must be set +** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various +** features that require the use of temporary files may fail. +** +** See also: [sqlite3_temp_directory] +*/ +int sqlite3_open( + const char *filename, /* Database filename (UTF-8) */ + sqlite3 **ppDb /* OUT: SQLite db handle */ +); +int sqlite3_open16( + const void *filename, /* Database filename (UTF-16) */ + sqlite3 **ppDb /* OUT: SQLite db handle */ +); +int sqlite3_open_v2( + const char *filename, /* Database filename (UTF-8) */ + sqlite3 **ppDb, /* OUT: SQLite db handle */ + int flags, /* Flags */ + const char *zVfs /* Name of VFS module to use */ +); + +/* +** CAPI3REF: Obtain Values For URI Parameters +** +** These are utility routines, useful to [VFS|custom VFS implementations], +** that check if a database file was a URI that contained a specific query +** parameter, and if so obtains the value of that query parameter. +** +** The first parameter to these interfaces (hereafter referred to +** as F) must be one of: +** <ul> +** <li> A database filename pointer created by the SQLite core and +** passed into the xOpen() method of a VFS implemention, or +** <li> A filename obtained from [sqlite3_db_filename()], or +** <li> A new filename constructed using [sqlite3_create_filename()]. +** </ul> +** If the F parameter is not one of the above, then the behavior is +** undefined and probably undesirable. Older versions of SQLite were +** more tolerant of invalid F parameters than newer versions. +** +** If F is a suitable filename (as described in the previous paragraph) +** and if P is the name of the query parameter, then +** sqlite3_uri_parameter(F,P) returns the value of the P +** parameter if it exists or a NULL pointer if P does not appear as a +** query parameter on F. If P is a query parameter of F and it +** has no explicit value, then sqlite3_uri_parameter(F,P) returns +** a pointer to an empty string. +** +** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean +** parameter and returns true (1) or false (0) according to the value +** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the +** value of query parameter P is one of "yes", "true", or "on" in any +** case or if the value begins with a non-zero number. The +** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of +** query parameter P is one of "no", "false", or "off" in any case or +** if the value begins with a numeric zero. If P is not a query +** parameter on F or if the value of P does not match any of the +** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). +** +** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a +** 64-bit signed integer and returns that integer, or D if P does not +** exist. If the value of P is something other than an integer, then +** zero is returned. +** +** The sqlite3_uri_key(F,N) returns a pointer to the name (not +** the value) of the N-th query parameter for filename F, or a NULL +** pointer if N is less than zero or greater than the number of query +** parameters minus 1. The N value is zero-based so N should be 0 to obtain +** the name of the first query parameter, 1 for the second parameter, and +** so forth. +** +** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and +** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and +** is not a database file pathname pointer that the SQLite core passed +** into the xOpen VFS method, then the behavior of this routine is undefined +** and probably undesirable. +** +** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F +** parameter can also be the name of a rollback journal file or WAL file +** in addition to the main database file. Prior to version 3.31.0, these +** routines would only work if F was the name of the main database file. +** When the F parameter is the name of the rollback journal or WAL file, +** it has access to all the same query parameters as were found on the +** main database file. +** +** See the [URI filename] documentation for additional information. +*/ +const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); +int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); +sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); +const char *sqlite3_uri_key(sqlite3_filename z, int N); + +/* +** CAPI3REF: Translate filenames +** +** These routines are available to [VFS|custom VFS implementations] for +** translating filenames between the main database file, the journal file, +** and the WAL file. +** +** If F is the name of an sqlite database file, journal file, or WAL file +** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) +** returns the name of the corresponding database file. +** +** If F is the name of an sqlite database file, journal file, or WAL file +** passed by the SQLite core into the VFS, or if F is a database filename +** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) +** returns the name of the corresponding rollback journal file. +** +** If F is the name of an sqlite database file, journal file, or WAL file +** that was passed by the SQLite core into the VFS, or if F is a database +** filename obtained from [sqlite3_db_filename()], then +** sqlite3_filename_wal(F) returns the name of the corresponding +** WAL file. +** +** In all of the above, if F is not the name of a database, journal or WAL +** filename passed into the VFS from the SQLite core and F is not the +** return value from [sqlite3_db_filename()], then the result is +** undefined and is likely a memory access violation. +*/ +const char *sqlite3_filename_database(sqlite3_filename); +const char *sqlite3_filename_journal(sqlite3_filename); +const char *sqlite3_filename_wal(sqlite3_filename); + +/* +** CAPI3REF: Database File Corresponding To A Journal +** +** ^If X is the name of a rollback or WAL-mode journal file that is +** passed into the xOpen method of [sqlite3_vfs], then +** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] +** object that represents the main database file. +** +** This routine is intended for use in custom [VFS] implementations +** only. It is not a general-purpose interface. +** The argument sqlite3_file_object(X) must be a filename pointer that +** has been passed into [sqlite3_vfs].xOpen method where the +** flags parameter to xOpen contains one of the bits +** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use +** of this routine results in undefined and probably undesirable +** behavior. +*/ +sqlite3_file *sqlite3_database_file_object(const char*); + +/* +** CAPI3REF: Create and Destroy VFS Filenames +** +** These interfces are provided for use by [VFS shim] implementations and +** are not useful outside of that context. +** +** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of +** database filename D with corresponding journal file J and WAL file W and +** with N URI parameters key/values pairs in the array P. The result from +** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that +** is safe to pass to routines like: +** <ul> +** <li> [sqlite3_uri_parameter()], +** <li> [sqlite3_uri_boolean()], +** <li> [sqlite3_uri_int64()], +** <li> [sqlite3_uri_key()], +** <li> [sqlite3_filename_database()], +** <li> [sqlite3_filename_journal()], or +** <li> [sqlite3_filename_wal()]. +** </ul> +** If a memory allocation error occurs, sqlite3_create_filename() might +** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) +** must be released by a corresponding call to sqlite3_free_filename(Y). +** +** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array +** of 2*N pointers to strings. Each pair of pointers in this array corresponds +** to a key and value for a query parameter. The P parameter may be a NULL +** pointer if N is zero. None of the 2*N pointers in the P array may be +** NULL pointers and key pointers should not be empty strings. +** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may +** be NULL pointers, though they can be empty strings. +** +** The sqlite3_free_filename(Y) routine releases a memory allocation +** previously obtained from sqlite3_create_filename(). Invoking +** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. +** +** If the Y parameter to sqlite3_free_filename(Y) is anything other +** than a NULL pointer or a pointer previously acquired from +** sqlite3_create_filename(), then bad things such as heap +** corruption or segfaults may occur. The value Y should not be +** used again after sqlite3_free_filename(Y) has been called. This means +** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, +** then the corresponding [sqlite3_module.xClose() method should also be +** invoked prior to calling sqlite3_free_filename(Y). +*/ +sqlite3_filename sqlite3_create_filename( + const char *zDatabase, + const char *zJournal, + const char *zWal, + int nParam, + const char **azParam +); +void sqlite3_free_filename(sqlite3_filename); + +/* +** CAPI3REF: Error Codes And Messages +** METHOD: sqlite3 +** +** ^If the most recent sqlite3_* API call associated with +** [database connection] D failed, then the sqlite3_errcode(D) interface +** returns the numeric [result code] or [extended result code] for that +** API call. +** ^The sqlite3_extended_errcode() +** interface is the same except that it always returns the +** [extended result code] even when extended result codes are +** disabled. +** +** The values returned by sqlite3_errcode() and/or +** sqlite3_extended_errcode() might change with each API call. +** Except, there are some interfaces that are guaranteed to never +** change the value of the error code. The error-code preserving +** interfaces include the following: +** +** <ul> +** <li> sqlite3_errcode() +** <li> sqlite3_extended_errcode() +** <li> sqlite3_errmsg() +** <li> sqlite3_errmsg16() +** <li> sqlite3_error_offset() +** </ul> +** +** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language +** text that describes the error, as either UTF-8 or UTF-16 respectively. +** ^(Memory to hold the error message string is managed internally. +** The application does not need to worry about freeing the result. +** However, the error string might be overwritten or deallocated by +** subsequent calls to other SQLite interface functions.)^ +** +** ^The sqlite3_errstr() interface returns the English-language text +** that describes the [result code], as UTF-8. +** ^(Memory to hold the error message string is managed internally +** and must not be freed by the application)^. +** +** ^If the most recent error references a specific token in the input +** SQL, the sqlite3_error_offset() interface returns the byte offset +** of the start of that token. ^The byte offset returned by +** sqlite3_error_offset() assumes that the input SQL is UTF8. +** ^If the most recent error does not reference a specific token in the input +** SQL, then the sqlite3_error_offset() function returns -1. +** +** When the serialized [threading mode] is in use, it might be the +** case that a second error occurs on a separate thread in between +** the time of the first error and the call to these interfaces. +** When that happens, the second error will be reported since these +** interfaces always report the most recent result. To avoid +** this, each thread can obtain exclusive use of the [database connection] D +** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning +** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after +** all calls to the interfaces listed here are completed. +** +** If an interface fails with SQLITE_MISUSE, that means the interface +** was invoked incorrectly by the application. In that case, the +** error code and message may or may not be set. +*/ +int sqlite3_errcode(sqlite3 *db); +int sqlite3_extended_errcode(sqlite3 *db); +const char *sqlite3_errmsg(sqlite3*); +const void *sqlite3_errmsg16(sqlite3*); +const char *sqlite3_errstr(int); +int sqlite3_error_offset(sqlite3 *db); + +/* +** CAPI3REF: Prepared Statement Object +** KEYWORDS: {prepared statement} {prepared statements} +** +** An instance of this object represents a single SQL statement that +** has been compiled into binary form and is ready to be evaluated. +** +** Think of each SQL statement as a separate computer program. The +** original SQL text is source code. A prepared statement object +** is the compiled object code. All SQL must be converted into a +** prepared statement before it can be run. +** +** The life-cycle of a prepared statement object usually goes like this: +** +** <ol> +** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. +** <li> Bind values to [parameters] using the sqlite3_bind_*() +** interfaces. +** <li> Run the SQL by calling [sqlite3_step()] one or more times. +** <li> Reset the prepared statement using [sqlite3_reset()] then go back +** to step 2. Do this zero or more times. +** <li> Destroy the object using [sqlite3_finalize()]. +** </ol> +*/ +typedef struct sqlite3_stmt sqlite3_stmt; + +/* +** CAPI3REF: Run-time Limits +** METHOD: sqlite3 +** +** ^(This interface allows the size of various constructs to be limited +** on a connection by connection basis. The first parameter is the +** [database connection] whose limit is to be set or queried. The +** second parameter is one of the [limit categories] that define a +** class of constructs to be size limited. The third parameter is the +** new limit for that construct.)^ +** +** ^If the new limit is a negative number, the limit is unchanged. +** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a +** [limits | hard upper bound] +** set at compile-time by a C preprocessor macro called +** [limits | SQLITE_MAX_<i>NAME</i>]. +** (The "_LIMIT_" in the name is changed to "_MAX_".))^ +** ^Attempts to increase a limit above its hard upper bound are +** silently truncated to the hard upper bound. +** +** ^Regardless of whether or not the limit was changed, the +** [sqlite3_limit()] interface returns the prior value of the limit. +** ^Hence, to find the current value of a limit without changing it, +** simply invoke this interface with the third parameter set to -1. +** +** Run-time limits are intended for use in applications that manage +** both their own internal database and also databases that are controlled +** by untrusted external sources. An example application might be a +** web browser that has its own databases for storing history and +** separate databases controlled by JavaScript applications downloaded +** off the Internet. The internal databases can be given the +** large, default limits. Databases managed by external sources can +** be given much smaller limits designed to prevent a denial of service +** attack. Developers might also want to use the [sqlite3_set_authorizer()] +** interface to further control untrusted SQL. The size of the database +** created by an untrusted script can be contained using the +** [max_page_count] [PRAGMA]. +** +** New run-time limit categories may be added in future releases. +*/ +int sqlite3_limit(sqlite3*, int id, int newVal); + +/* +** CAPI3REF: Run-Time Limit Categories +** KEYWORDS: {limit category} {*limit categories} +** +** These constants define various performance limits +** that can be lowered at run-time using [sqlite3_limit()]. +** The synopsis of the meanings of the various limits is shown below. +** Additional information is available at [limits | Limits in SQLite]. +** +** <dl> +** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> +** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ +** +** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> +** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ +** +** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> +** <dd>The maximum number of columns in a table definition or in the +** result set of a [SELECT] or the maximum number of columns in an index +** or in an ORDER BY or GROUP BY clause.</dd>)^ +** +** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> +** <dd>The maximum depth of the parse tree on any expression.</dd>)^ +** +** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> +** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ +** +** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> +** <dd>The maximum number of instructions in a virtual machine program +** used to implement an SQL statement. If [sqlite3_prepare_v2()] or +** the equivalent tries to allocate space for more than this many opcodes +** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ +** +** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> +** <dd>The maximum number of arguments on a function.</dd>)^ +** +** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> +** <dd>The maximum number of [ATTACH | attached databases].)^</dd> +** +** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] +** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> +** <dd>The maximum length of the pattern argument to the [LIKE] or +** [GLOB] operators.</dd>)^ +** +** [[SQLITE_LIMIT_VARIABLE_NUMBER]] +** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> +** <dd>The maximum index number of any [parameter] in an SQL statement.)^ +** +** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> +** <dd>The maximum depth of recursion for triggers.</dd>)^ +** +** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> +** <dd>The maximum number of auxiliary worker threads that a single +** [prepared statement] may start.</dd>)^ +** </dl> +*/ +#define SQLITE_LIMIT_LENGTH 0 +#define SQLITE_LIMIT_SQL_LENGTH 1 +#define SQLITE_LIMIT_COLUMN 2 +#define SQLITE_LIMIT_EXPR_DEPTH 3 +#define SQLITE_LIMIT_COMPOUND_SELECT 4 +#define SQLITE_LIMIT_VDBE_OP 5 +#define SQLITE_LIMIT_FUNCTION_ARG 6 +#define SQLITE_LIMIT_ATTACHED 7 +#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 +#define SQLITE_LIMIT_VARIABLE_NUMBER 9 +#define SQLITE_LIMIT_TRIGGER_DEPTH 10 +#define SQLITE_LIMIT_WORKER_THREADS 11 + +/* +** CAPI3REF: Prepare Flags +** +** These constants define various flags that can be passed into +** "prepFlags" parameter of the [sqlite3_prepare_v3()] and +** [sqlite3_prepare16_v3()] interfaces. +** +** New flags may be added in future releases of SQLite. +** +** <dl> +** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> +** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner +** that the prepared statement will be retained for a long time and +** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] +** and [sqlite3_prepare16_v3()] assume that the prepared statement will +** be used just once or at most a few times and then destroyed using +** [sqlite3_finalize()] relatively soon. The current implementation acts +** on this hint by avoiding the use of [lookaside memory] so as not to +** deplete the limited store of lookaside memory. Future versions of +** SQLite may act on this hint differently. +** +** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> +** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used +** to be required for any prepared statement that wanted to use the +** [sqlite3_normalized_sql()] interface. However, the +** [sqlite3_normalized_sql()] interface is now available to all +** prepared statements, regardless of whether or not they use this +** flag. +** +** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> +** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler +** to return an error (error code SQLITE_ERROR) if the statement uses +** any virtual tables. +** </dl> +*/ +#define SQLITE_PREPARE_PERSISTENT 0x01 +#define SQLITE_PREPARE_NORMALIZE 0x02 +#define SQLITE_PREPARE_NO_VTAB 0x04 + +/* +** CAPI3REF: Compiling An SQL Statement +** KEYWORDS: {SQL statement compiler} +** METHOD: sqlite3 +** CONSTRUCTOR: sqlite3_stmt +** +** To execute an SQL statement, it must first be compiled into a byte-code +** program using one of these routines. Or, in other words, these routines +** are constructors for the [prepared statement] object. +** +** The preferred routine to use is [sqlite3_prepare_v2()]. The +** [sqlite3_prepare()] interface is legacy and should be avoided. +** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used +** for special purposes. +** +** The use of the UTF-8 interfaces is preferred, as SQLite currently +** does all parsing using UTF-8. The UTF-16 interfaces are provided +** as a convenience. The UTF-16 interfaces work by converting the +** input text into UTF-8, then invoking the corresponding UTF-8 interface. +** +** The first argument, "db", is a [database connection] obtained from a +** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or +** [sqlite3_open16()]. The database connection must not have been closed. +** +** The second argument, "zSql", is the statement to be compiled, encoded +** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), +** and sqlite3_prepare_v3() +** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), +** and sqlite3_prepare16_v3() use UTF-16. +** +** ^If the nByte argument is negative, then zSql is read up to the +** first zero terminator. ^If nByte is positive, then it is the +** number of bytes read from zSql. ^If nByte is zero, then no prepared +** statement is generated. +** If the caller knows that the supplied string is nul-terminated, then +** there is a small performance advantage to passing an nByte parameter that +** is the number of bytes in the input string <i>including</i> +** the nul-terminator. +** +** ^If pzTail is not NULL then *pzTail is made to point to the first byte +** past the end of the first SQL statement in zSql. These routines only +** compile the first statement in zSql, so *pzTail is left pointing to +** what remains uncompiled. +** +** ^*ppStmt is left pointing to a compiled [prepared statement] that can be +** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set +** to NULL. ^If the input text contains no SQL (if the input is an empty +** string or a comment) then *ppStmt is set to NULL. +** The calling procedure is responsible for deleting the compiled +** SQL statement using [sqlite3_finalize()] after it has finished with it. +** ppStmt may not be NULL. +** +** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; +** otherwise an [error code] is returned. +** +** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), +** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. +** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) +** are retained for backwards compatibility, but their use is discouraged. +** ^In the "vX" interfaces, the prepared statement +** that is returned (the [sqlite3_stmt] object) contains a copy of the +** original SQL text. This causes the [sqlite3_step()] interface to +** behave differently in three ways: +** +** <ol> +** <li> +** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it +** always used to do, [sqlite3_step()] will automatically recompile the SQL +** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] +** retries will occur before sqlite3_step() gives up and returns an error. +** </li> +** +** <li> +** ^When an error occurs, [sqlite3_step()] will return one of the detailed +** [error codes] or [extended error codes]. ^The legacy behavior was that +** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code +** and the application would have to make a second call to [sqlite3_reset()] +** in order to find the underlying cause of the problem. With the "v2" prepare +** interfaces, the underlying reason for the error is returned immediately. +** </li> +** +** <li> +** ^If the specific value bound to a [parameter | host parameter] in the +** WHERE clause might influence the choice of query plan for a statement, +** then the statement will be automatically recompiled, as if there had been +** a schema change, on the first [sqlite3_step()] call following any change +** to the [sqlite3_bind_text | bindings] of that [parameter]. +** ^The specific value of a WHERE-clause [parameter] might influence the +** choice of query plan if the parameter is the left-hand side of a [LIKE] +** or [GLOB] operator or if the parameter is compared to an indexed column +** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. +** </li> +** </ol> +** +** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having +** the extra prepFlags parameter, which is a bit array consisting of zero or +** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The +** sqlite3_prepare_v2() interface works exactly the same as +** sqlite3_prepare_v3() with a zero prepFlags parameter. +*/ +int sqlite3_prepare( + sqlite3 *db, /* Database handle */ + const char *zSql, /* SQL statement, UTF-8 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const char **pzTail /* OUT: Pointer to unused portion of zSql */ +); +int sqlite3_prepare_v2( + sqlite3 *db, /* Database handle */ + const char *zSql, /* SQL statement, UTF-8 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const char **pzTail /* OUT: Pointer to unused portion of zSql */ +); +int sqlite3_prepare_v3( + sqlite3 *db, /* Database handle */ + const char *zSql, /* SQL statement, UTF-8 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const char **pzTail /* OUT: Pointer to unused portion of zSql */ +); +int sqlite3_prepare16( + sqlite3 *db, /* Database handle */ + const void *zSql, /* SQL statement, UTF-16 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const void **pzTail /* OUT: Pointer to unused portion of zSql */ +); +int sqlite3_prepare16_v2( + sqlite3 *db, /* Database handle */ + const void *zSql, /* SQL statement, UTF-16 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const void **pzTail /* OUT: Pointer to unused portion of zSql */ +); +int sqlite3_prepare16_v3( + sqlite3 *db, /* Database handle */ + const void *zSql, /* SQL statement, UTF-16 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const void **pzTail /* OUT: Pointer to unused portion of zSql */ +); + +/* +** CAPI3REF: Retrieving Statement SQL +** METHOD: sqlite3_stmt +** +** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 +** SQL text used to create [prepared statement] P if P was +** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], +** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. +** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 +** string containing the SQL text of prepared statement P with +** [bound parameters] expanded. +** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 +** string containing the normalized SQL text of prepared statement P. The +** semantics used to normalize a SQL statement are unspecified and subject +** to change. At a minimum, literal values will be replaced with suitable +** placeholders. +** +** ^(For example, if a prepared statement is created using the SQL +** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 +** and parameter :xyz is unbound, then sqlite3_sql() will return +** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() +** will return "SELECT 2345,NULL".)^ +** +** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory +** is available to hold the result, or if the result would exceed the +** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. +** +** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of +** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time +** option causes sqlite3_expanded_sql() to always return NULL. +** +** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) +** are managed by SQLite and are automatically freed when the prepared +** statement is finalized. +** ^The string returned by sqlite3_expanded_sql(P), on the other hand, +** is obtained from [sqlite3_malloc()] and must be freed by the application +** by passing it to [sqlite3_free()]. +** +** ^The sqlite3_normalized_sql() interface is only available if +** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. +*/ +const char *sqlite3_sql(sqlite3_stmt *pStmt); +char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); +#ifdef SQLITE_ENABLE_NORMALIZE +const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); +#endif + +/* +** CAPI3REF: Determine If An SQL Statement Writes The Database +** METHOD: sqlite3_stmt +** +** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if +** and only if the [prepared statement] X makes no direct changes to +** the content of the database file. +** +** Note that [application-defined SQL functions] or +** [virtual tables] might change the database indirectly as a side effect. +** ^(For example, if an application defines a function "eval()" that +** calls [sqlite3_exec()], then the following SQL statement would +** change the database file through side-effects: +** +** <blockquote><pre> +** SELECT eval('DELETE FROM t1') FROM t2; +** </pre></blockquote> +** +** But because the [SELECT] statement does not change the database file +** directly, sqlite3_stmt_readonly() would still return true.)^ +** +** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], +** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, +** since the statements themselves do not actually modify the database but +** rather they control the timing of when other statements modify the +** database. ^The [ATTACH] and [DETACH] statements also cause +** sqlite3_stmt_readonly() to return true since, while those statements +** change the configuration of a database connection, they do not make +** changes to the content of the database files on disk. +** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since +** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and +** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so +** sqlite3_stmt_readonly() returns false for those commands. +** +** ^This routine returns false if there is any possibility that the +** statement might change the database file. ^A false return does +** not guarantee that the statement will change the database file. +** ^For example, an UPDATE statement might have a WHERE clause that +** makes it a no-op, but the sqlite3_stmt_readonly() result would still +** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a +** read-only no-op if the table already exists, but +** sqlite3_stmt_readonly() still returns false for such a statement. +** +** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] +** statement, then sqlite3_stmt_readonly(X) returns the same value as +** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. +*/ +int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement +** METHOD: sqlite3_stmt +** +** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the +** prepared statement S is an EXPLAIN statement, or 2 if the +** statement S is an EXPLAIN QUERY PLAN. +** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is +** an ordinary statement or a NULL pointer. +*/ +int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Determine If A Prepared Statement Has Been Reset +** METHOD: sqlite3_stmt +** +** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the +** [prepared statement] S has been stepped at least once using +** [sqlite3_step(S)] but has neither run to completion (returned +** [SQLITE_DONE] from [sqlite3_step(S)]) nor +** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) +** interface returns false if S is a NULL pointer. If S is not a +** NULL pointer and is not a pointer to a valid [prepared statement] +** object, then the behavior is undefined and probably undesirable. +** +** This interface can be used in combination [sqlite3_next_stmt()] +** to locate all prepared statements associated with a database +** connection that are in need of being reset. This can be used, +** for example, in diagnostic routines to search for prepared +** statements that are holding a transaction open. +*/ +int sqlite3_stmt_busy(sqlite3_stmt*); + +/* +** CAPI3REF: Dynamically Typed Value Object +** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} +** +** SQLite uses the sqlite3_value object to represent all values +** that can be stored in a database table. SQLite uses dynamic typing +** for the values it stores. ^Values stored in sqlite3_value objects +** can be integers, floating point values, strings, BLOBs, or NULL. +** +** An sqlite3_value object may be either "protected" or "unprotected". +** Some interfaces require a protected sqlite3_value. Other interfaces +** will accept either a protected or an unprotected sqlite3_value. +** Every interface that accepts sqlite3_value arguments specifies +** whether or not it requires a protected sqlite3_value. The +** [sqlite3_value_dup()] interface can be used to construct a new +** protected sqlite3_value from an unprotected sqlite3_value. +** +** The terms "protected" and "unprotected" refer to whether or not +** a mutex is held. An internal mutex is held for a protected +** sqlite3_value object but no mutex is held for an unprotected +** sqlite3_value object. If SQLite is compiled to be single-threaded +** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) +** or if SQLite is run in one of reduced mutex modes +** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] +** then there is no distinction between protected and unprotected +** sqlite3_value objects and they can be used interchangeably. However, +** for maximum code portability it is recommended that applications +** still make the distinction between protected and unprotected +** sqlite3_value objects even when not strictly required. +** +** ^The sqlite3_value objects that are passed as parameters into the +** implementation of [application-defined SQL functions] are protected. +** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] +** are protected. +** ^The sqlite3_value object returned by +** [sqlite3_column_value()] is unprotected. +** Unprotected sqlite3_value objects may only be used as arguments +** to [sqlite3_result_value()], [sqlite3_bind_value()], and +** [sqlite3_value_dup()]. +** The [sqlite3_value_blob | sqlite3_value_type()] family of +** interfaces require protected sqlite3_value objects. +*/ +typedef struct sqlite3_value sqlite3_value; + +/* +** CAPI3REF: SQL Function Context Object +** +** The context in which an SQL function executes is stored in an +** sqlite3_context object. ^A pointer to an sqlite3_context object +** is always first parameter to [application-defined SQL functions]. +** The application-defined SQL function implementation will pass this +** pointer through into calls to [sqlite3_result_int | sqlite3_result()], +** [sqlite3_aggregate_context()], [sqlite3_user_data()], +** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], +** and/or [sqlite3_set_auxdata()]. +*/ +typedef struct sqlite3_context sqlite3_context; + +/* +** CAPI3REF: Binding Values To Prepared Statements +** KEYWORDS: {host parameter} {host parameters} {host parameter name} +** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} +** METHOD: sqlite3_stmt +** +** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, +** literals may be replaced by a [parameter] that matches one of following +** templates: +** +** <ul> +** <li> ? +** <li> ?NNN +** <li> :VVV +** <li> @VVV +** <li> $VVV +** </ul> +** +** In the templates above, NNN represents an integer literal, +** and VVV represents an alphanumeric identifier.)^ ^The values of these +** parameters (also called "host parameter names" or "SQL parameters") +** can be set using the sqlite3_bind_*() routines defined here. +** +** ^The first argument to the sqlite3_bind_*() routines is always +** a pointer to the [sqlite3_stmt] object returned from +** [sqlite3_prepare_v2()] or its variants. +** +** ^The second argument is the index of the SQL parameter to be set. +** ^The leftmost SQL parameter has an index of 1. ^When the same named +** SQL parameter is used more than once, second and subsequent +** occurrences have the same index as the first occurrence. +** ^The index for named parameters can be looked up using the +** [sqlite3_bind_parameter_index()] API if desired. ^The index +** for "?NNN" parameters is the value of NNN. +** ^The NNN value must be between 1 and the [sqlite3_limit()] +** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). +** +** ^The third argument is the value to bind to the parameter. +** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() +** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter +** is ignored and the end result is the same as sqlite3_bind_null(). +** ^If the third parameter to sqlite3_bind_text() is not NULL, then +** it should be a pointer to well-formed UTF8 text. +** ^If the third parameter to sqlite3_bind_text16() is not NULL, then +** it should be a pointer to well-formed UTF16 text. +** ^If the third parameter to sqlite3_bind_text64() is not NULL, then +** it should be a pointer to a well-formed unicode string that is +** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 +** otherwise. +** +** [[byte-order determination rules]] ^The byte-order of +** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) +** found in first character, which is removed, or in the absence of a BOM +** the byte order is the native byte order of the host +** machine for sqlite3_bind_text16() or the byte order specified in +** the 6th parameter for sqlite3_bind_text64().)^ +** ^If UTF16 input text contains invalid unicode +** characters, then SQLite might change those invalid characters +** into the unicode replacement character: U+FFFD. +** +** ^(In those routines that have a fourth argument, its value is the +** number of bytes in the parameter. To be clear: the value is the +** number of <u>bytes</u> in the value, not the number of characters.)^ +** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() +** is negative, then the length of the string is +** the number of bytes up to the first zero terminator. +** If the fourth parameter to sqlite3_bind_blob() is negative, then +** the behavior is undefined. +** If a non-negative fourth parameter is provided to sqlite3_bind_text() +** or sqlite3_bind_text16() or sqlite3_bind_text64() then +** that parameter must be the byte offset +** where the NUL terminator would occur assuming the string were NUL +** terminated. If any NUL characters occurs at byte offsets less than +** the value of the fourth parameter then the resulting string value will +** contain embedded NULs. The result of expressions involving strings +** with embedded NULs is undefined. +** +** ^The fifth argument to the BLOB and string binding interfaces controls +** or indicates the lifetime of the object referenced by the third parameter. +** These three options exist: +** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished +** with it may be passed. ^It is called to dispose of the BLOB or string even +** if the call to the bind API fails, except the destructor is not called if +** the third parameter is a NULL pointer or the fourth parameter is negative. +** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that +** the application remains responsible for disposing of the object. ^In this +** case, the object and the provided pointer to it must remain valid until +** either the prepared statement is finalized or the same SQL parameter is +** bound to something else, whichever occurs sooner. +** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the +** object is to be copied prior to the return from sqlite3_bind_*(). ^The +** object and pointer to it must remain valid until then. ^SQLite will then +** manage the lifetime of its private copy. +** +** ^The sixth argument to sqlite3_bind_text64() must be one of +** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] +** to specify the encoding of the text in the third parameter. If +** the sixth argument to sqlite3_bind_text64() is not one of the +** allowed values shown above, or if the text encoding is different +** from the encoding specified by the sixth parameter, then the behavior +** is undefined. +** +** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that +** is filled with zeroes. ^A zeroblob uses a fixed amount of memory +** (just an integer to hold its size) while it is being processed. +** Zeroblobs are intended to serve as placeholders for BLOBs whose +** content is later written using +** [sqlite3_blob_open | incremental BLOB I/O] routines. +** ^A negative value for the zeroblob results in a zero-length BLOB. +** +** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in +** [prepared statement] S to have an SQL value of NULL, but to also be +** associated with the pointer P of type T. ^D is either a NULL pointer or +** a pointer to a destructor function for P. ^SQLite will invoke the +** destructor D with a single argument of P when it is finished using +** P. The T parameter should be a static string, preferably a string +** literal. The sqlite3_bind_pointer() routine is part of the +** [pointer passing interface] added for SQLite 3.20.0. +** +** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer +** for the [prepared statement] or with a prepared statement for which +** [sqlite3_step()] has been called more recently than [sqlite3_reset()], +** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() +** routine is passed a [prepared statement] that has been finalized, the +** result is undefined and probably harmful. +** +** ^Bindings are not cleared by the [sqlite3_reset()] routine. +** ^Unbound parameters are interpreted as NULL. +** +** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an +** [error code] if anything goes wrong. +** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB +** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or +** [SQLITE_MAX_LENGTH]. +** ^[SQLITE_RANGE] is returned if the parameter +** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. +** +** See also: [sqlite3_bind_parameter_count()], +** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. +*/ +int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); +int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, + void(*)(void*)); +int sqlite3_bind_double(sqlite3_stmt*, int, double); +int sqlite3_bind_int(sqlite3_stmt*, int, int); +int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); +int sqlite3_bind_null(sqlite3_stmt*, int); +int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); +int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); +int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, + void(*)(void*), unsigned char encoding); +int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); +int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); +int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); +int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); + +/* +** CAPI3REF: Number Of SQL Parameters +** METHOD: sqlite3_stmt +** +** ^This routine can be used to find the number of [SQL parameters] +** in a [prepared statement]. SQL parameters are tokens of the +** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as +** placeholders for values that are [sqlite3_bind_blob | bound] +** to the parameters at a later time. +** +** ^(This routine actually returns the index of the largest (rightmost) +** parameter. For all forms except ?NNN, this will correspond to the +** number of unique parameters. If parameters of the ?NNN form are used, +** there may be gaps in the list.)^ +** +** See also: [sqlite3_bind_blob|sqlite3_bind()], +** [sqlite3_bind_parameter_name()], and +** [sqlite3_bind_parameter_index()]. +*/ +int sqlite3_bind_parameter_count(sqlite3_stmt*); + +/* +** CAPI3REF: Name Of A Host Parameter +** METHOD: sqlite3_stmt +** +** ^The sqlite3_bind_parameter_name(P,N) interface returns +** the name of the N-th [SQL parameter] in the [prepared statement] P. +** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" +** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" +** respectively. +** In other words, the initial ":" or "$" or "@" or "?" +** is included as part of the name.)^ +** ^Parameters of the form "?" without a following integer have no name +** and are referred to as "nameless" or "anonymous parameters". +** +** ^The first host parameter has an index of 1, not 0. +** +** ^If the value N is out of range or if the N-th parameter is +** nameless, then NULL is returned. ^The returned string is +** always in UTF-8 encoding even if the named parameter was +** originally specified as UTF-16 in [sqlite3_prepare16()], +** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. +** +** See also: [sqlite3_bind_blob|sqlite3_bind()], +** [sqlite3_bind_parameter_count()], and +** [sqlite3_bind_parameter_index()]. +*/ +const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); + +/* +** CAPI3REF: Index Of A Parameter With A Given Name +** METHOD: sqlite3_stmt +** +** ^Return the index of an SQL parameter given its name. ^The +** index value returned is suitable for use as the second +** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero +** is returned if no matching parameter is found. ^The parameter +** name must be given in UTF-8 even if the original statement +** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or +** [sqlite3_prepare16_v3()]. +** +** See also: [sqlite3_bind_blob|sqlite3_bind()], +** [sqlite3_bind_parameter_count()], and +** [sqlite3_bind_parameter_name()]. +*/ +int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); + +/* +** CAPI3REF: Reset All Bindings On A Prepared Statement +** METHOD: sqlite3_stmt +** +** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset +** the [sqlite3_bind_blob | bindings] on a [prepared statement]. +** ^Use this routine to reset all host parameters to NULL. +*/ +int sqlite3_clear_bindings(sqlite3_stmt*); + +/* +** CAPI3REF: Number Of Columns In A Result Set +** METHOD: sqlite3_stmt +** +** ^Return the number of columns in the result set returned by the +** [prepared statement]. ^If this routine returns 0, that means the +** [prepared statement] returns no data (for example an [UPDATE]). +** ^However, just because this routine returns a positive number does not +** mean that one or more rows of data will be returned. ^A SELECT statement +** will always have a positive sqlite3_column_count() but depending on the +** WHERE clause constraints and the table content, it might return no rows. +** +** See also: [sqlite3_data_count()] +*/ +int sqlite3_column_count(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Column Names In A Result Set +** METHOD: sqlite3_stmt +** +** ^These routines return the name assigned to a particular column +** in the result set of a [SELECT] statement. ^The sqlite3_column_name() +** interface returns a pointer to a zero-terminated UTF-8 string +** and sqlite3_column_name16() returns a pointer to a zero-terminated +** UTF-16 string. ^The first parameter is the [prepared statement] +** that implements the [SELECT] statement. ^The second parameter is the +** column number. ^The leftmost column is number 0. +** +** ^The returned string pointer is valid until either the [prepared statement] +** is destroyed by [sqlite3_finalize()] or until the statement is automatically +** reprepared by the first call to [sqlite3_step()] for a particular run +** or until the next call to +** sqlite3_column_name() or sqlite3_column_name16() on the same column. +** +** ^If sqlite3_malloc() fails during the processing of either routine +** (for example during a conversion from UTF-8 to UTF-16) then a +** NULL pointer is returned. +** +** ^The name of a result column is the value of the "AS" clause for +** that column, if there is an AS clause. If there is no AS clause +** then the name of the column is unspecified and may change from +** one release of SQLite to the next. +*/ +const char *sqlite3_column_name(sqlite3_stmt*, int N); +const void *sqlite3_column_name16(sqlite3_stmt*, int N); + +/* +** CAPI3REF: Source Of Data In A Query Result +** METHOD: sqlite3_stmt +** +** ^These routines provide a means to determine the database, table, and +** table column that is the origin of a particular result column in +** [SELECT] statement. +** ^The name of the database or table or column can be returned as +** either a UTF-8 or UTF-16 string. ^The _database_ routines return +** the database name, the _table_ routines return the table name, and +** the origin_ routines return the column name. +** ^The returned string is valid until the [prepared statement] is destroyed +** using [sqlite3_finalize()] or until the statement is automatically +** reprepared by the first call to [sqlite3_step()] for a particular run +** or until the same information is requested +** again in a different encoding. +** +** ^The names returned are the original un-aliased names of the +** database, table, and column. +** +** ^The first argument to these interfaces is a [prepared statement]. +** ^These functions return information about the Nth result column returned by +** the statement, where N is the second function argument. +** ^The left-most column is column 0 for these routines. +** +** ^If the Nth column returned by the statement is an expression or +** subquery and is not a column value, then all of these functions return +** NULL. ^These routines might also return NULL if a memory allocation error +** occurs. ^Otherwise, they return the name of the attached database, table, +** or column that query result column was extracted from. +** +** ^As with all other SQLite APIs, those whose names end with "16" return +** UTF-16 encoded strings and the other functions return UTF-8. +** +** ^These APIs are only available if the library was compiled with the +** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. +** +** If two or more threads call one or more +** [sqlite3_column_database_name | column metadata interfaces] +** for the same [prepared statement] and result column +** at the same time then the results are undefined. +*/ +const char *sqlite3_column_database_name(sqlite3_stmt*,int); +const void *sqlite3_column_database_name16(sqlite3_stmt*,int); +const char *sqlite3_column_table_name(sqlite3_stmt*,int); +const void *sqlite3_column_table_name16(sqlite3_stmt*,int); +const char *sqlite3_column_origin_name(sqlite3_stmt*,int); +const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); + +/* +** CAPI3REF: Declared Datatype Of A Query Result +** METHOD: sqlite3_stmt +** +** ^(The first parameter is a [prepared statement]. +** If this statement is a [SELECT] statement and the Nth column of the +** returned result set of that [SELECT] is a table column (not an +** expression or subquery) then the declared type of the table +** column is returned.)^ ^If the Nth column of the result set is an +** expression or subquery, then a NULL pointer is returned. +** ^The returned string is always UTF-8 encoded. +** +** ^(For example, given the database schema: +** +** CREATE TABLE t1(c1 VARIANT); +** +** and the following statement to be compiled: +** +** SELECT c1 + 1, c1 FROM t1; +** +** this routine would return the string "VARIANT" for the second result +** column (i==1), and a NULL pointer for the first result column (i==0).)^ +** +** ^SQLite uses dynamic run-time typing. ^So just because a column +** is declared to contain a particular type does not mean that the +** data stored in that column is of the declared type. SQLite is +** strongly typed, but the typing is dynamic not static. ^Type +** is associated with individual values, not with the containers +** used to hold those values. +*/ +const char *sqlite3_column_decltype(sqlite3_stmt*,int); +const void *sqlite3_column_decltype16(sqlite3_stmt*,int); + +/* +** CAPI3REF: Evaluate An SQL Statement +** METHOD: sqlite3_stmt +** +** After a [prepared statement] has been prepared using any of +** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], +** or [sqlite3_prepare16_v3()] or one of the legacy +** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function +** must be called one or more times to evaluate the statement. +** +** The details of the behavior of the sqlite3_step() interface depend +** on whether the statement was prepared using the newer "vX" interfaces +** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], +** [sqlite3_prepare16_v2()] or the older legacy +** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the +** new "vX" interface is recommended for new applications but the legacy +** interface will continue to be supported. +** +** ^In the legacy interface, the return value will be either [SQLITE_BUSY], +** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. +** ^With the "v2" interface, any of the other [result codes] or +** [extended result codes] might be returned as well. +** +** ^[SQLITE_BUSY] means that the database engine was unable to acquire the +** database locks it needs to do its job. ^If the statement is a [COMMIT] +** or occurs outside of an explicit transaction, then you can retry the +** statement. If the statement is not a [COMMIT] and occurs within an +** explicit transaction then you should rollback the transaction before +** continuing. +** +** ^[SQLITE_DONE] means that the statement has finished executing +** successfully. sqlite3_step() should not be called again on this virtual +** machine without first calling [sqlite3_reset()] to reset the virtual +** machine back to its initial state. +** +** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] +** is returned each time a new row of data is ready for processing by the +** caller. The values may be accessed using the [column access functions]. +** sqlite3_step() is called again to retrieve the next row of data. +** +** ^[SQLITE_ERROR] means that a run-time error (such as a constraint +** violation) has occurred. sqlite3_step() should not be called again on +** the VM. More information may be found by calling [sqlite3_errmsg()]. +** ^With the legacy interface, a more specific error code (for example, +** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) +** can be obtained by calling [sqlite3_reset()] on the +** [prepared statement]. ^In the "v2" interface, +** the more specific error code is returned directly by sqlite3_step(). +** +** [SQLITE_MISUSE] means that the this routine was called inappropriately. +** Perhaps it was called on a [prepared statement] that has +** already been [sqlite3_finalize | finalized] or on one that had +** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could +** be the case that the same database connection is being used by two or +** more threads at the same moment in time. +** +** For all versions of SQLite up to and including 3.6.23.1, a call to +** [sqlite3_reset()] was required after sqlite3_step() returned anything +** other than [SQLITE_ROW] before any subsequent invocation of +** sqlite3_step(). Failure to reset the prepared statement using +** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from +** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], +** sqlite3_step() began +** calling [sqlite3_reset()] automatically in this circumstance rather +** than returning [SQLITE_MISUSE]. This is not considered a compatibility +** break because any application that ever receives an SQLITE_MISUSE error +** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option +** can be used to restore the legacy behavior. +** +** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() +** API always returns a generic error code, [SQLITE_ERROR], following any +** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call +** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the +** specific [error codes] that better describes the error. +** We admit that this is a goofy design. The problem has been fixed +** with the "v2" interface. If you prepare all of your SQL statements +** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] +** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead +** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, +** then the more specific [error codes] are returned directly +** by sqlite3_step(). The use of the "vX" interfaces is recommended. +*/ +int sqlite3_step(sqlite3_stmt*); + +/* +** CAPI3REF: Number of columns in a result set +** METHOD: sqlite3_stmt +** +** ^The sqlite3_data_count(P) interface returns the number of columns in the +** current row of the result set of [prepared statement] P. +** ^If prepared statement P does not have results ready to return +** (via calls to the [sqlite3_column_int | sqlite3_column()] family of +** interfaces) then sqlite3_data_count(P) returns 0. +** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. +** ^The sqlite3_data_count(P) routine returns 0 if the previous call to +** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) +** will return non-zero if previous call to [sqlite3_step](P) returned +** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] +** where it always returns zero since each step of that multi-step +** pragma returns 0 columns of data. +** +** See also: [sqlite3_column_count()] +*/ +int sqlite3_data_count(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Fundamental Datatypes +** KEYWORDS: SQLITE_TEXT +** +** ^(Every value in SQLite has one of five fundamental datatypes: +** +** <ul> +** <li> 64-bit signed integer +** <li> 64-bit IEEE floating point number +** <li> string +** <li> BLOB +** <li> NULL +** </ul>)^ +** +** These constants are codes for each of those types. +** +** Note that the SQLITE_TEXT constant was also used in SQLite version 2 +** for a completely different meaning. Software that links against both +** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not +** SQLITE_TEXT. +*/ +#define SQLITE_INTEGER 1 +#define SQLITE_FLOAT 2 +#define SQLITE_BLOB 4 +#define SQLITE_NULL 5 +#ifdef SQLITE_TEXT +# undef SQLITE_TEXT +#else +# define SQLITE_TEXT 3 +#endif +#define SQLITE3_TEXT 3 + +/* +** CAPI3REF: Result Values From A Query +** KEYWORDS: {column access functions} +** METHOD: sqlite3_stmt +** +** <b>Summary:</b> +** <blockquote><table border=0 cellpadding=0 cellspacing=0> +** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result +** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result +** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result +** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result +** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result +** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result +** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an +** [sqlite3_value|unprotected sqlite3_value] object. +** <tr><td> <td> <td> +** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB +** or a UTF-8 TEXT result in bytes +** <tr><td><b>sqlite3_column_bytes16 </b> +** <td>→ <td>Size of UTF-16 +** TEXT in bytes +** <tr><td><b>sqlite3_column_type</b><td>→<td>Default +** datatype of the result +** </table></blockquote> +** +** <b>Details:</b> +** +** ^These routines return information about a single column of the current +** result row of a query. ^In every case the first argument is a pointer +** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] +** that was returned from [sqlite3_prepare_v2()] or one of its variants) +** and the second argument is the index of the column for which information +** should be returned. ^The leftmost column of the result set has the index 0. +** ^The number of columns in the result can be determined using +** [sqlite3_column_count()]. +** +** If the SQL statement does not currently point to a valid row, or if the +** column index is out of range, the result is undefined. +** These routines may only be called when the most recent call to +** [sqlite3_step()] has returned [SQLITE_ROW] and neither +** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. +** If any of these routines are called after [sqlite3_reset()] or +** [sqlite3_finalize()] or after [sqlite3_step()] has returned +** something other than [SQLITE_ROW], the results are undefined. +** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] +** are called from a different thread while any of these routines +** are pending, then the results are undefined. +** +** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) +** each return the value of a result column in a specific data format. If +** the result column is not initially in the requested format (for example, +** if the query returns an integer but the sqlite3_column_text() interface +** is used to extract the value) then an automatic type conversion is performed. +** +** ^The sqlite3_column_type() routine returns the +** [SQLITE_INTEGER | datatype code] for the initial data type +** of the result column. ^The returned value is one of [SQLITE_INTEGER], +** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. +** The return value of sqlite3_column_type() can be used to decide which +** of the first six interface should be used to extract the column value. +** The value returned by sqlite3_column_type() is only meaningful if no +** automatic type conversions have occurred for the value in question. +** After a type conversion, the result of calling sqlite3_column_type() +** is undefined, though harmless. Future +** versions of SQLite may change the behavior of sqlite3_column_type() +** following a type conversion. +** +** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() +** or sqlite3_column_bytes16() interfaces can be used to determine the size +** of that BLOB or string. +** +** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() +** routine returns the number of bytes in that BLOB or string. +** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts +** the string to UTF-8 and then returns the number of bytes. +** ^If the result is a numeric value then sqlite3_column_bytes() uses +** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns +** the number of bytes in that string. +** ^If the result is NULL, then sqlite3_column_bytes() returns zero. +** +** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() +** routine returns the number of bytes in that BLOB or string. +** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts +** the string to UTF-16 and then returns the number of bytes. +** ^If the result is a numeric value then sqlite3_column_bytes16() uses +** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns +** the number of bytes in that string. +** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. +** +** ^The values returned by [sqlite3_column_bytes()] and +** [sqlite3_column_bytes16()] do not include the zero terminators at the end +** of the string. ^For clarity: the values returned by +** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of +** bytes in the string, not the number of characters. +** +** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), +** even empty strings, are always zero-terminated. ^The return +** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. +** +** ^Strings returned by sqlite3_column_text16() always have the endianness +** which is native to the platform, regardless of the text encoding set +** for the database. +** +** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an +** [unprotected sqlite3_value] object. In a multithreaded environment, +** an unprotected sqlite3_value object may only be used safely with +** [sqlite3_bind_value()] and [sqlite3_result_value()]. +** If the [unprotected sqlite3_value] object returned by +** [sqlite3_column_value()] is used in any other way, including calls +** to routines like [sqlite3_value_int()], [sqlite3_value_text()], +** or [sqlite3_value_bytes()], the behavior is not threadsafe. +** Hence, the sqlite3_column_value() interface +** is normally only useful within the implementation of +** [application-defined SQL functions] or [virtual tables], not within +** top-level application code. +** +** These routines may attempt to convert the datatype of the result. +** ^For example, if the internal representation is FLOAT and a text result +** is requested, [sqlite3_snprintf()] is used internally to perform the +** conversion automatically. ^(The following table details the conversions +** that are applied: +** +** <blockquote> +** <table border="1"> +** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion +** +** <tr><td> NULL <td> INTEGER <td> Result is 0 +** <tr><td> NULL <td> FLOAT <td> Result is 0.0 +** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer +** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer +** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float +** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer +** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT +** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER +** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float +** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB +** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER +** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL +** <tr><td> TEXT <td> BLOB <td> No change +** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER +** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL +** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator +** </table> +** </blockquote>)^ +** +** Note that when type conversions occur, pointers returned by prior +** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or +** sqlite3_column_text16() may be invalidated. +** Type conversions and pointer invalidations might occur +** in the following cases: +** +** <ul> +** <li> The initial content is a BLOB and sqlite3_column_text() or +** sqlite3_column_text16() is called. A zero-terminator might +** need to be added to the string.</li> +** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or +** sqlite3_column_text16() is called. The content must be converted +** to UTF-16.</li> +** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or +** sqlite3_column_text() is called. The content must be converted +** to UTF-8.</li> +** </ul> +** +** ^Conversions between UTF-16be and UTF-16le are always done in place and do +** not invalidate a prior pointer, though of course the content of the buffer +** that the prior pointer references will have been modified. Other kinds +** of conversion are done in place when it is possible, but sometimes they +** are not possible and in those cases prior pointers are invalidated. +** +** The safest policy is to invoke these routines +** in one of the following ways: +** +** <ul> +** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> +** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> +** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> +** </ul> +** +** In other words, you should call sqlite3_column_text(), +** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result +** into the desired format, then invoke sqlite3_column_bytes() or +** sqlite3_column_bytes16() to find the size of the result. Do not mix calls +** to sqlite3_column_text() or sqlite3_column_blob() with calls to +** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() +** with calls to sqlite3_column_bytes(). +** +** ^The pointers returned are valid until a type conversion occurs as +** described above, or until [sqlite3_step()] or [sqlite3_reset()] or +** [sqlite3_finalize()] is called. ^The memory space used to hold strings +** and BLOBs is freed automatically. Do not pass the pointers returned +** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into +** [sqlite3_free()]. +** +** As long as the input parameters are correct, these routines will only +** fail if an out-of-memory error occurs during a format conversion. +** Only the following subset of interfaces are subject to out-of-memory +** errors: +** +** <ul> +** <li> sqlite3_column_blob() +** <li> sqlite3_column_text() +** <li> sqlite3_column_text16() +** <li> sqlite3_column_bytes() +** <li> sqlite3_column_bytes16() +** </ul> +** +** If an out-of-memory error occurs, then the return value from these +** routines is the same as if the column had contained an SQL NULL value. +** Valid SQL NULL returns can be distinguished from out-of-memory errors +** by invoking the [sqlite3_errcode()] immediately after the suspect +** return value is obtained and before any +** other SQLite interface is called on the same [database connection]. +*/ +const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); +double sqlite3_column_double(sqlite3_stmt*, int iCol); +int sqlite3_column_int(sqlite3_stmt*, int iCol); +sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); +const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); +const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); +sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); +int sqlite3_column_bytes(sqlite3_stmt*, int iCol); +int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); +int sqlite3_column_type(sqlite3_stmt*, int iCol); + +/* +** CAPI3REF: Destroy A Prepared Statement Object +** DESTRUCTOR: sqlite3_stmt +** +** ^The sqlite3_finalize() function is called to delete a [prepared statement]. +** ^If the most recent evaluation of the statement encountered no errors +** or if the statement is never been evaluated, then sqlite3_finalize() returns +** SQLITE_OK. ^If the most recent evaluation of statement S failed, then +** sqlite3_finalize(S) returns the appropriate [error code] or +** [extended error code]. +** +** ^The sqlite3_finalize(S) routine can be called at any point during +** the life cycle of [prepared statement] S: +** before statement S is ever evaluated, after +** one or more calls to [sqlite3_reset()], or after any call +** to [sqlite3_step()] regardless of whether or not the statement has +** completed execution. +** +** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. +** +** The application must finalize every [prepared statement] in order to avoid +** resource leaks. It is a grievous error for the application to try to use +** a prepared statement after it has been finalized. Any use of a prepared +** statement after it has been finalized can result in undefined and +** undesirable behavior such as segfaults and heap corruption. +*/ +int sqlite3_finalize(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Reset A Prepared Statement Object +** METHOD: sqlite3_stmt +** +** The sqlite3_reset() function is called to reset a [prepared statement] +** object back to its initial state, ready to be re-executed. +** ^Any SQL statement variables that had values bound to them using +** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. +** Use [sqlite3_clear_bindings()] to reset the bindings. +** +** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S +** back to the beginning of its program. +** +** ^If the most recent call to [sqlite3_step(S)] for the +** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], +** or if [sqlite3_step(S)] has never before been called on S, +** then [sqlite3_reset(S)] returns [SQLITE_OK]. +** +** ^If the most recent call to [sqlite3_step(S)] for the +** [prepared statement] S indicated an error, then +** [sqlite3_reset(S)] returns an appropriate [error code]. +** +** ^The [sqlite3_reset(S)] interface does not change the values +** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. +*/ +int sqlite3_reset(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Create Or Redefine SQL Functions +** KEYWORDS: {function creation routines} +** METHOD: sqlite3 +** +** ^These functions (collectively known as "function creation routines") +** are used to add SQL functions or aggregates or to redefine the behavior +** of existing SQL functions or aggregates. The only differences between +** the three "sqlite3_create_function*" routines are the text encoding +** expected for the second parameter (the name of the function being +** created) and the presence or absence of a destructor callback for +** the application data pointer. Function sqlite3_create_window_function() +** is similar, but allows the user to supply the extra callback functions +** needed by [aggregate window functions]. +** +** ^The first parameter is the [database connection] to which the SQL +** function is to be added. ^If an application uses more than one database +** connection then application-defined SQL functions must be added +** to each database connection separately. +** +** ^The second parameter is the name of the SQL function to be created or +** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 +** representation, exclusive of the zero-terminator. ^Note that the name +** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. +** ^Any attempt to create a function with a longer name +** will result in [SQLITE_MISUSE] being returned. +** +** ^The third parameter (nArg) +** is the number of arguments that the SQL function or +** aggregate takes. ^If this parameter is -1, then the SQL function or +** aggregate may take any number of arguments between 0 and the limit +** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third +** parameter is less than -1 or greater than 127 then the behavior is +** undefined. +** +** ^The fourth parameter, eTextRep, specifies what +** [SQLITE_UTF8 | text encoding] this SQL function prefers for +** its parameters. The application should set this parameter to +** [SQLITE_UTF16LE] if the function implementation invokes +** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the +** implementation invokes [sqlite3_value_text16be()] on an input, or +** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] +** otherwise. ^The same SQL function may be registered multiple times using +** different preferred text encodings, with different implementations for +** each encoding. +** ^When multiple implementations of the same function are available, SQLite +** will pick the one that involves the least amount of data conversion. +** +** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] +** to signal that the function will always return the same result given +** the same inputs within a single SQL statement. Most SQL functions are +** deterministic. The built-in [random()] SQL function is an example of a +** function that is not deterministic. The SQLite query planner is able to +** perform additional optimizations on deterministic functions, so use +** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. +** +** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] +** flag, which if present prevents the function from being invoked from +** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, +** index expressions, or the WHERE clause of partial indexes. +** +** For best security, the [SQLITE_DIRECTONLY] flag is recommended for +** all application-defined SQL functions that do not need to be +** used inside of triggers, view, CHECK constraints, or other elements of +** the database schema. This flags is especially recommended for SQL +** functions that have side effects or reveal internal application state. +** Without this flag, an attacker might be able to modify the schema of +** a database file to include invocations of the function with parameters +** chosen by the attacker, which the application will then execute when +** the database file is opened and read. +** +** ^(The fifth parameter is an arbitrary pointer. The implementation of the +** function can gain access to this pointer using [sqlite3_user_data()].)^ +** +** ^The sixth, seventh and eighth parameters passed to the three +** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are +** pointers to C-language functions that implement the SQL function or +** aggregate. ^A scalar SQL function requires an implementation of the xFunc +** callback only; NULL pointers must be passed as the xStep and xFinal +** parameters. ^An aggregate SQL function requires an implementation of xStep +** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing +** SQL function or aggregate, pass NULL pointers for all three function +** callbacks. +** +** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue +** and xInverse) passed to sqlite3_create_window_function are pointers to +** C-language callbacks that implement the new function. xStep and xFinal +** must both be non-NULL. xValue and xInverse may either both be NULL, in +** which case a regular aggregate function is created, or must both be +** non-NULL, in which case the new function may be used as either an aggregate +** or aggregate window function. More details regarding the implementation +** of aggregate window functions are +** [user-defined window functions|available here]. +** +** ^(If the final parameter to sqlite3_create_function_v2() or +** sqlite3_create_window_function() is not NULL, then it is destructor for +** the application data pointer. The destructor is invoked when the function +** is deleted, either by being overloaded or when the database connection +** closes.)^ ^The destructor is also invoked if the call to +** sqlite3_create_function_v2() fails. ^When the destructor callback is +** invoked, it is passed a single argument which is a copy of the application +** data pointer which was the fifth parameter to sqlite3_create_function_v2(). +** +** ^It is permitted to register multiple implementations of the same +** functions with the same name but with either differing numbers of +** arguments or differing preferred text encodings. ^SQLite will use +** the implementation that most closely matches the way in which the +** SQL function is used. ^A function implementation with a non-negative +** nArg parameter is a better match than a function implementation with +** a negative nArg. ^A function where the preferred text encoding +** matches the database encoding is a better +** match than a function where the encoding is different. +** ^A function where the encoding difference is between UTF16le and UTF16be +** is a closer match than a function where the encoding difference is +** between UTF8 and UTF16. +** +** ^Built-in functions may be overloaded by new application-defined functions. +** +** ^An application-defined function is permitted to call other +** SQLite interfaces. However, such calls must not +** close the database connection nor finalize or reset the prepared +** statement in which the function is running. +*/ +int sqlite3_create_function( + sqlite3 *db, + const char *zFunctionName, + int nArg, + int eTextRep, + void *pApp, + void (*xFunc)(sqlite3_context*,int,sqlite3_value**), + void (*xStep)(sqlite3_context*,int,sqlite3_value**), + void (*xFinal)(sqlite3_context*) +); +int sqlite3_create_function16( + sqlite3 *db, + const void *zFunctionName, + int nArg, + int eTextRep, + void *pApp, + void (*xFunc)(sqlite3_context*,int,sqlite3_value**), + void (*xStep)(sqlite3_context*,int,sqlite3_value**), + void (*xFinal)(sqlite3_context*) +); +int sqlite3_create_function_v2( + sqlite3 *db, + const char *zFunctionName, + int nArg, + int eTextRep, + void *pApp, + void (*xFunc)(sqlite3_context*,int,sqlite3_value**), + void (*xStep)(sqlite3_context*,int,sqlite3_value**), + void (*xFinal)(sqlite3_context*), + void(*xDestroy)(void*) +); +int sqlite3_create_window_function( + sqlite3 *db, + const char *zFunctionName, + int nArg, + int eTextRep, + void *pApp, + void (*xStep)(sqlite3_context*,int,sqlite3_value**), + void (*xFinal)(sqlite3_context*), + void (*xValue)(sqlite3_context*), + void (*xInverse)(sqlite3_context*,int,sqlite3_value**), + void(*xDestroy)(void*) +); + +/* +** CAPI3REF: Text Encodings +** +** These constant define integer codes that represent the various +** text encodings supported by SQLite. +*/ +#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ +#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ +#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ +#define SQLITE_UTF16 4 /* Use native byte order */ +#define SQLITE_ANY 5 /* Deprecated */ +#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ + +/* +** CAPI3REF: Function Flags +** +** These constants may be ORed together with the +** [SQLITE_UTF8 | preferred text encoding] as the fourth argument +** to [sqlite3_create_function()], [sqlite3_create_function16()], or +** [sqlite3_create_function_v2()]. +** +** <dl> +** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> +** The SQLITE_DETERMINISTIC flag means that the new function always gives +** the same output when the input parameters are the same. +** The [abs|abs() function] is deterministic, for example, but +** [randomblob|randomblob()] is not. Functions must +** be deterministic in order to be used in certain contexts such as +** with the WHERE clause of [partial indexes] or in [generated columns]. +** SQLite might also optimize deterministic functions by factoring them +** out of inner loops. +** </dd> +** +** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> +** The SQLITE_DIRECTONLY flag means that the function may only be invoked +** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in +** schema structures such as [CHECK constraints], [DEFAULT clauses], +** [expression indexes], [partial indexes], or [generated columns]. +** The SQLITE_DIRECTONLY flags is a security feature which is recommended +** for all [application-defined SQL functions], and especially for functions +** that have side-effects or that could potentially leak sensitive +** information. +** </dd> +** +** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> +** The SQLITE_INNOCUOUS flag means that the function is unlikely +** to cause problems even if misused. An innocuous function should have +** no side effects and should not depend on any values other than its +** input parameters. The [abs|abs() function] is an example of an +** innocuous function. +** The [load_extension() SQL function] is not innocuous because of its +** side effects. +** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not +** exactly the same. The [random|random() function] is an example of a +** function that is innocuous but not deterministic. +** <p>Some heightened security settings +** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) +** disable the use of SQL functions inside views and triggers and in +** schema structures such as [CHECK constraints], [DEFAULT clauses], +** [expression indexes], [partial indexes], and [generated columns] unless +** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions +** are innocuous. Developers are advised to avoid using the +** SQLITE_INNOCUOUS flag for application-defined functions unless the +** function has been carefully audited and found to be free of potentially +** security-adverse side-effects and information-leaks. +** </dd> +** +** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> +** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call +** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. +** Specifying this flag makes no difference for scalar or aggregate user +** functions. However, if it is not specified for a user-defined window +** function, then any sub-types belonging to arguments passed to the window +** function may be discarded before the window function is called (i.e. +** sqlite3_value_subtype() will always return 0). +** </dd> +** </dl> +*/ +#define SQLITE_DETERMINISTIC 0x000000800 +#define SQLITE_DIRECTONLY 0x000080000 +#define SQLITE_SUBTYPE 0x000100000 +#define SQLITE_INNOCUOUS 0x000200000 + +/* +** CAPI3REF: Deprecated Functions +** DEPRECATED +** +** These functions are [deprecated]. In order to maintain +** backwards compatibility with older code, these functions continue +** to be supported. However, new applications should avoid +** the use of these functions. To encourage programmers to avoid +** these functions, we will not explain what they do. +*/ +#ifndef SQLITE_OMIT_DEPRECATED +SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); +SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); +SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); +SQLITE_DEPRECATED int sqlite3_global_recover(void); +SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); +SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), + void*,sqlite3_int64); +#endif + +/* +** CAPI3REF: Obtaining SQL Values +** METHOD: sqlite3_value +** +** <b>Summary:</b> +** <blockquote><table border=0 cellpadding=0 cellspacing=0> +** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value +** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value +** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value +** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value +** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value +** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value +** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in +** the native byteorder +** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value +** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value +** <tr><td> <td> <td> +** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB +** or a UTF-8 TEXT in bytes +** <tr><td><b>sqlite3_value_bytes16 </b> +** <td>→ <td>Size of UTF-16 +** TEXT in bytes +** <tr><td><b>sqlite3_value_type</b><td>→<td>Default +** datatype of the value +** <tr><td><b>sqlite3_value_numeric_type </b> +** <td>→ <td>Best numeric datatype of the value +** <tr><td><b>sqlite3_value_nochange </b> +** <td>→ <td>True if the column is unchanged in an UPDATE +** against a virtual table. +** <tr><td><b>sqlite3_value_frombind </b> +** <td>→ <td>True if value originated from a [bound parameter] +** </table></blockquote> +** +** <b>Details:</b> +** +** These routines extract type, size, and content information from +** [protected sqlite3_value] objects. Protected sqlite3_value objects +** are used to pass parameter information into the functions that +** implement [application-defined SQL functions] and [virtual tables]. +** +** These routines work only with [protected sqlite3_value] objects. +** Any attempt to use these routines on an [unprotected sqlite3_value] +** is not threadsafe. +** +** ^These routines work just like the corresponding [column access functions] +** except that these routines take a single [protected sqlite3_value] object +** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. +** +** ^The sqlite3_value_text16() interface extracts a UTF-16 string +** in the native byte-order of the host machine. ^The +** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces +** extract UTF-16 strings as big-endian and little-endian respectively. +** +** ^If [sqlite3_value] object V was initialized +** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] +** and if X and Y are strings that compare equal according to strcmp(X,Y), +** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, +** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() +** routine is part of the [pointer passing interface] added for SQLite 3.20.0. +** +** ^(The sqlite3_value_type(V) interface returns the +** [SQLITE_INTEGER | datatype code] for the initial datatype of the +** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], +** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ +** Other interfaces might change the datatype for an sqlite3_value object. +** For example, if the datatype is initially SQLITE_INTEGER and +** sqlite3_value_text(V) is called to extract a text value for that +** integer, then subsequent calls to sqlite3_value_type(V) might return +** SQLITE_TEXT. Whether or not a persistent internal datatype conversion +** occurs is undefined and may change from one release of SQLite to the next. +** +** ^(The sqlite3_value_numeric_type() interface attempts to apply +** numeric affinity to the value. This means that an attempt is +** made to convert the value to an integer or floating point. If +** such a conversion is possible without loss of information (in other +** words, if the value is a string that looks like a number) +** then the conversion is performed. Otherwise no conversion occurs. +** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ +** +** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], +** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current encoding +** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) +** returns something other than SQLITE_TEXT, then the return value from +** sqlite3_value_encoding(X) is meaningless. ^Calls to +** sqlite3_value_text(X), sqlite3_value_text16(X), sqlite3_value_text16be(X), +** sqlite3_value_text16le(X), sqlite3_value_bytes(X), or +** sqlite3_value_bytes16(X) might change the encoding of the value X and +** thus change the return from subsequent calls to sqlite3_value_encoding(X). +** +** ^Within the [xUpdate] method of a [virtual table], the +** sqlite3_value_nochange(X) interface returns true if and only if +** the column corresponding to X is unchanged by the UPDATE operation +** that the xUpdate method call was invoked to implement and if +** and the prior [xColumn] method call that was invoked to extracted +** the value for that column returned without setting a result (probably +** because it queried [sqlite3_vtab_nochange()] and found that the column +** was unchanging). ^Within an [xUpdate] method, any value for which +** sqlite3_value_nochange(X) is true will in all other respects appear +** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other +** than within an [xUpdate] method call for an UPDATE statement, then +** the return value is arbitrary and meaningless. +** +** ^The sqlite3_value_frombind(X) interface returns non-zero if the +** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] +** interfaces. ^If X comes from an SQL literal value, or a table column, +** or an expression, then sqlite3_value_frombind(X) returns zero. +** +** Please pay particular attention to the fact that the pointer returned +** from [sqlite3_value_blob()], [sqlite3_value_text()], or +** [sqlite3_value_text16()] can be invalidated by a subsequent call to +** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], +** or [sqlite3_value_text16()]. +** +** These routines must be called from the same thread as +** the SQL function that supplied the [sqlite3_value*] parameters. +** +** As long as the input parameter is correct, these routines can only +** fail if an out-of-memory error occurs during a format conversion. +** Only the following subset of interfaces are subject to out-of-memory +** errors: +** +** <ul> +** <li> sqlite3_value_blob() +** <li> sqlite3_value_text() +** <li> sqlite3_value_text16() +** <li> sqlite3_value_text16le() +** <li> sqlite3_value_text16be() +** <li> sqlite3_value_bytes() +** <li> sqlite3_value_bytes16() +** </ul> +** +** If an out-of-memory error occurs, then the return value from these +** routines is the same as if the column had contained an SQL NULL value. +** Valid SQL NULL returns can be distinguished from out-of-memory errors +** by invoking the [sqlite3_errcode()] immediately after the suspect +** return value is obtained and before any +** other SQLite interface is called on the same [database connection]. +*/ +const void *sqlite3_value_blob(sqlite3_value*); +double sqlite3_value_double(sqlite3_value*); +int sqlite3_value_int(sqlite3_value*); +sqlite3_int64 sqlite3_value_int64(sqlite3_value*); +void *sqlite3_value_pointer(sqlite3_value*, const char*); +const unsigned char *sqlite3_value_text(sqlite3_value*); +const void *sqlite3_value_text16(sqlite3_value*); +const void *sqlite3_value_text16le(sqlite3_value*); +const void *sqlite3_value_text16be(sqlite3_value*); +int sqlite3_value_bytes(sqlite3_value*); +int sqlite3_value_bytes16(sqlite3_value*); +int sqlite3_value_type(sqlite3_value*); +int sqlite3_value_numeric_type(sqlite3_value*); +int sqlite3_value_nochange(sqlite3_value*); +int sqlite3_value_frombind(sqlite3_value*); +int sqlite3_value_encoding(sqlite3_value*); + +/* +** CAPI3REF: Finding The Subtype Of SQL Values +** METHOD: sqlite3_value +** +** The sqlite3_value_subtype(V) function returns the subtype for +** an [application-defined SQL function] argument V. The subtype +** information can be used to pass a limited amount of context from +** one SQL function to another. Use the [sqlite3_result_subtype()] +** routine to set the subtype for the return value of an SQL function. +*/ +unsigned int sqlite3_value_subtype(sqlite3_value*); + +/* +** CAPI3REF: Copy And Free SQL Values +** METHOD: sqlite3_value +** +** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] +** object D and returns a pointer to that copy. ^The [sqlite3_value] returned +** is a [protected sqlite3_value] object even if the input is not. +** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a +** memory allocation fails. ^If V is a [pointer value], then the result +** of sqlite3_value_dup(V) is a NULL value. +** +** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object +** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer +** then sqlite3_value_free(V) is a harmless no-op. +*/ +sqlite3_value *sqlite3_value_dup(const sqlite3_value*); +void sqlite3_value_free(sqlite3_value*); + +/* +** CAPI3REF: Obtain Aggregate Function Context +** METHOD: sqlite3_context +** +** Implementations of aggregate SQL functions use this +** routine to allocate memory for storing their state. +** +** ^The first time the sqlite3_aggregate_context(C,N) routine is called +** for a particular aggregate function, SQLite allocates +** N bytes of memory, zeroes out that memory, and returns a pointer +** to the new memory. ^On second and subsequent calls to +** sqlite3_aggregate_context() for the same aggregate function instance, +** the same buffer is returned. Sqlite3_aggregate_context() is normally +** called once for each invocation of the xStep callback and then one +** last time when the xFinal callback is invoked. ^(When no rows match +** an aggregate query, the xStep() callback of the aggregate function +** implementation is never called and xFinal() is called exactly once. +** In those cases, sqlite3_aggregate_context() might be called for the +** first time from within xFinal().)^ +** +** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer +** when first called if N is less than or equal to zero or if a memory +** allocation error occurs. +** +** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is +** determined by the N parameter on first successful call. Changing the +** value of N in any subsequent call to sqlite3_aggregate_context() within +** the same aggregate function instance will not resize the memory +** allocation.)^ Within the xFinal callback, it is customary to set +** N=0 in calls to sqlite3_aggregate_context(C,N) so that no +** pointless memory allocations occur. +** +** ^SQLite automatically frees the memory allocated by +** sqlite3_aggregate_context() when the aggregate query concludes. +** +** The first parameter must be a copy of the +** [sqlite3_context | SQL function context] that is the first parameter +** to the xStep or xFinal callback routine that implements the aggregate +** function. +** +** This routine must be called from the same thread in which +** the aggregate SQL function is running. +*/ +void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); + +/* +** CAPI3REF: User Data For Functions +** METHOD: sqlite3_context +** +** ^The sqlite3_user_data() interface returns a copy of +** the pointer that was the pUserData parameter (the 5th parameter) +** of the [sqlite3_create_function()] +** and [sqlite3_create_function16()] routines that originally +** registered the application defined function. +** +** This routine must be called from the same thread in which +** the application-defined function is running. +*/ +void *sqlite3_user_data(sqlite3_context*); + +/* +** CAPI3REF: Database Connection For Functions +** METHOD: sqlite3_context +** +** ^The sqlite3_context_db_handle() interface returns a copy of +** the pointer to the [database connection] (the 1st parameter) +** of the [sqlite3_create_function()] +** and [sqlite3_create_function16()] routines that originally +** registered the application defined function. +*/ +sqlite3 *sqlite3_context_db_handle(sqlite3_context*); + +/* +** CAPI3REF: Function Auxiliary Data +** METHOD: sqlite3_context +** +** These functions may be used by (non-aggregate) SQL functions to +** associate metadata with argument values. If the same value is passed to +** multiple invocations of the same SQL function during query execution, under +** some circumstances the associated metadata may be preserved. An example +** of where this might be useful is in a regular-expression matching +** function. The compiled version of the regular expression can be stored as +** metadata associated with the pattern string. +** Then as long as the pattern string remains the same, +** the compiled regular expression can be reused on multiple +** invocations of the same function. +** +** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata +** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument +** value to the application-defined function. ^N is zero for the left-most +** function argument. ^If there is no metadata +** associated with the function argument, the sqlite3_get_auxdata(C,N) interface +** returns a NULL pointer. +** +** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th +** argument of the application-defined function. ^Subsequent +** calls to sqlite3_get_auxdata(C,N) return P from the most recent +** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or +** NULL if the metadata has been discarded. +** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, +** SQLite will invoke the destructor function X with parameter P exactly +** once, when the metadata is discarded. +** SQLite is free to discard the metadata at any time, including: <ul> +** <li> ^(when the corresponding function parameter changes)^, or +** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the +** SQL statement)^, or +** <li> ^(when sqlite3_set_auxdata() is invoked again on the same +** parameter)^, or +** <li> ^(during the original sqlite3_set_auxdata() call when a memory +** allocation error occurs.)^ </ul> +** +** Note the last bullet in particular. The destructor X in +** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the +** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() +** should be called near the end of the function implementation and the +** function implementation should not make any use of P after +** sqlite3_set_auxdata() has been called. +** +** ^(In practice, metadata is preserved between function calls for +** function parameters that are compile-time constants, including literal +** values and [parameters] and expressions composed from the same.)^ +** +** The value of the N parameter to these interfaces should be non-negative. +** Future enhancements may make use of negative N values to define new +** kinds of function caching behavior. +** +** These routines must be called from the same thread in which +** the SQL function is running. +*/ +void *sqlite3_get_auxdata(sqlite3_context*, int N); +void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); + + +/* +** CAPI3REF: Constants Defining Special Destructor Behavior +** +** These are special values for the destructor that is passed in as the +** final argument to routines like [sqlite3_result_blob()]. ^If the destructor +** argument is SQLITE_STATIC, it means that the content pointer is constant +** and will never change. It does not need to be destroyed. ^The +** SQLITE_TRANSIENT value means that the content will likely change in +** the near future and that SQLite should make its own private copy of +** the content before returning. +** +** The typedef is necessary to work around problems in certain +** C++ compilers. +*/ +typedef void (*sqlite3_destructor_type)(void*); +#define SQLITE_STATIC ((sqlite3_destructor_type)0) +#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) + +/* +** CAPI3REF: Setting The Result Of An SQL Function +** METHOD: sqlite3_context +** +** These routines are used by the xFunc or xFinal callbacks that +** implement SQL functions and aggregates. See +** [sqlite3_create_function()] and [sqlite3_create_function16()] +** for additional information. +** +** These functions work very much like the [parameter binding] family of +** functions used to bind values to host parameters in prepared statements. +** Refer to the [SQL parameter] documentation for additional information. +** +** ^The sqlite3_result_blob() interface sets the result from +** an application-defined function to be the BLOB whose content is pointed +** to by the second parameter and which is N bytes long where N is the +** third parameter. +** +** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) +** interfaces set the result of the application-defined function to be +** a BLOB containing all zero bytes and N bytes in size. +** +** ^The sqlite3_result_double() interface sets the result from +** an application-defined function to be a floating point value specified +** by its 2nd argument. +** +** ^The sqlite3_result_error() and sqlite3_result_error16() functions +** cause the implemented SQL function to throw an exception. +** ^SQLite uses the string pointed to by the +** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() +** as the text of an error message. ^SQLite interprets the error +** message string from sqlite3_result_error() as UTF-8. ^SQLite +** interprets the string from sqlite3_result_error16() as UTF-16 using +** the same [byte-order determination rules] as [sqlite3_bind_text16()]. +** ^If the third parameter to sqlite3_result_error() +** or sqlite3_result_error16() is negative then SQLite takes as the error +** message all text up through the first zero character. +** ^If the third parameter to sqlite3_result_error() or +** sqlite3_result_error16() is non-negative then SQLite takes that many +** bytes (not characters) from the 2nd parameter as the error message. +** ^The sqlite3_result_error() and sqlite3_result_error16() +** routines make a private copy of the error message text before +** they return. Hence, the calling function can deallocate or +** modify the text after they return without harm. +** ^The sqlite3_result_error_code() function changes the error code +** returned by SQLite as a result of an error in a function. ^By default, +** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() +** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. +** +** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an +** error indicating that a string or BLOB is too long to represent. +** +** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an +** error indicating that a memory allocation failed. +** +** ^The sqlite3_result_int() interface sets the return value +** of the application-defined function to be the 32-bit signed integer +** value given in the 2nd argument. +** ^The sqlite3_result_int64() interface sets the return value +** of the application-defined function to be the 64-bit signed integer +** value given in the 2nd argument. +** +** ^The sqlite3_result_null() interface sets the return value +** of the application-defined function to be NULL. +** +** ^The sqlite3_result_text(), sqlite3_result_text16(), +** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces +** set the return value of the application-defined function to be +** a text string which is represented as UTF-8, UTF-16 native byte order, +** UTF-16 little endian, or UTF-16 big endian, respectively. +** ^The sqlite3_result_text64() interface sets the return value of an +** application-defined function to be a text string in an encoding +** specified by the fifth (and last) parameter, which must be one +** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. +** ^SQLite takes the text result from the application from +** the 2nd parameter of the sqlite3_result_text* interfaces. +** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces +** other than sqlite3_result_text64() is negative, then SQLite computes +** the string length itself by searching the 2nd parameter for the first +** zero character. +** ^If the 3rd parameter to the sqlite3_result_text* interfaces +** is non-negative, then as many bytes (not characters) of the text +** pointed to by the 2nd parameter are taken as the application-defined +** function result. If the 3rd parameter is non-negative, then it +** must be the byte offset into the string where the NUL terminator would +** appear if the string where NUL terminated. If any NUL characters occur +** in the string at a byte offset that is less than the value of the 3rd +** parameter, then the resulting string will contain embedded NULs and the +** result of expressions operating on strings with embedded NULs is undefined. +** ^If the 4th parameter to the sqlite3_result_text* interfaces +** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that +** function as the destructor on the text or BLOB result when it has +** finished using that result. +** ^If the 4th parameter to the sqlite3_result_text* interfaces or to +** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite +** assumes that the text or BLOB result is in constant space and does not +** copy the content of the parameter nor call a destructor on the content +** when it has finished using that result. +** ^If the 4th parameter to the sqlite3_result_text* interfaces +** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT +** then SQLite makes a copy of the result into space obtained +** from [sqlite3_malloc()] before it returns. +** +** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and +** sqlite3_result_text16be() routines, and for sqlite3_result_text64() +** when the encoding is not UTF8, if the input UTF16 begins with a +** byte-order mark (BOM, U+FEFF) then the BOM is removed from the +** string and the rest of the string is interpreted according to the +** byte-order specified by the BOM. ^The byte-order specified by +** the BOM at the beginning of the text overrides the byte-order +** specified by the interface procedure. ^So, for example, if +** sqlite3_result_text16le() is invoked with text that begins +** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the +** first two bytes of input are skipped and the remaining input +** is interpreted as UTF16BE text. +** +** ^For UTF16 input text to the sqlite3_result_text16(), +** sqlite3_result_text16be(), sqlite3_result_text16le(), and +** sqlite3_result_text64() routines, if the text contains invalid +** UTF16 characters, the invalid characters might be converted +** into the unicode replacement character, U+FFFD. +** +** ^The sqlite3_result_value() interface sets the result of +** the application-defined function to be a copy of the +** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The +** sqlite3_result_value() interface makes a copy of the [sqlite3_value] +** so that the [sqlite3_value] specified in the parameter may change or +** be deallocated after sqlite3_result_value() returns without harm. +** ^A [protected sqlite3_value] object may always be used where an +** [unprotected sqlite3_value] object is required, so either +** kind of [sqlite3_value] object can be used with this interface. +** +** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an +** SQL NULL value, just like [sqlite3_result_null(C)], except that it +** also associates the host-language pointer P or type T with that +** NULL value such that the pointer can be retrieved within an +** [application-defined SQL function] using [sqlite3_value_pointer()]. +** ^If the D parameter is not NULL, then it is a pointer to a destructor +** for the P parameter. ^SQLite invokes D with P as its only argument +** when SQLite is finished with P. The T parameter should be a static +** string and preferably a string literal. The sqlite3_result_pointer() +** routine is part of the [pointer passing interface] added for SQLite 3.20.0. +** +** If these routines are called from within the different thread +** than the one containing the application-defined function that received +** the [sqlite3_context] pointer, the results are undefined. +*/ +void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); +void sqlite3_result_blob64(sqlite3_context*,const void*, + sqlite3_uint64,void(*)(void*)); +void sqlite3_result_double(sqlite3_context*, double); +void sqlite3_result_error(sqlite3_context*, const char*, int); +void sqlite3_result_error16(sqlite3_context*, const void*, int); +void sqlite3_result_error_toobig(sqlite3_context*); +void sqlite3_result_error_nomem(sqlite3_context*); +void sqlite3_result_error_code(sqlite3_context*, int); +void sqlite3_result_int(sqlite3_context*, int); +void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); +void sqlite3_result_null(sqlite3_context*); +void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); +void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, + void(*)(void*), unsigned char encoding); +void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); +void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); +void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); +void sqlite3_result_value(sqlite3_context*, sqlite3_value*); +void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); +void sqlite3_result_zeroblob(sqlite3_context*, int n); +int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); + + +/* +** CAPI3REF: Setting The Subtype Of An SQL Function +** METHOD: sqlite3_context +** +** The sqlite3_result_subtype(C,T) function causes the subtype of +** the result from the [application-defined SQL function] with +** [sqlite3_context] C to be the value T. Only the lower 8 bits +** of the subtype T are preserved in current versions of SQLite; +** higher order bits are discarded. +** The number of subtype bytes preserved by SQLite might increase +** in future releases of SQLite. +*/ +void sqlite3_result_subtype(sqlite3_context*,unsigned int); + +/* +** CAPI3REF: Define New Collating Sequences +** METHOD: sqlite3 +** +** ^These functions add, remove, or modify a [collation] associated +** with the [database connection] specified as the first argument. +** +** ^The name of the collation is a UTF-8 string +** for sqlite3_create_collation() and sqlite3_create_collation_v2() +** and a UTF-16 string in native byte order for sqlite3_create_collation16(). +** ^Collation names that compare equal according to [sqlite3_strnicmp()] are +** considered to be the same name. +** +** ^(The third argument (eTextRep) must be one of the constants: +** <ul> +** <li> [SQLITE_UTF8], +** <li> [SQLITE_UTF16LE], +** <li> [SQLITE_UTF16BE], +** <li> [SQLITE_UTF16], or +** <li> [SQLITE_UTF16_ALIGNED]. +** </ul>)^ +** ^The eTextRep argument determines the encoding of strings passed +** to the collating function callback, xCompare. +** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep +** force strings to be UTF16 with native byte order. +** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin +** on an even byte address. +** +** ^The fourth argument, pArg, is an application data pointer that is passed +** through as the first argument to the collating function callback. +** +** ^The fifth argument, xCompare, is a pointer to the collating function. +** ^Multiple collating functions can be registered using the same name but +** with different eTextRep parameters and SQLite will use whichever +** function requires the least amount of data transformation. +** ^If the xCompare argument is NULL then the collating function is +** deleted. ^When all collating functions having the same name are deleted, +** that collation is no longer usable. +** +** ^The collating function callback is invoked with a copy of the pArg +** application data pointer and with two strings in the encoding specified +** by the eTextRep argument. The two integer parameters to the collating +** function callback are the length of the two strings, in bytes. The collating +** function must return an integer that is negative, zero, or positive +** if the first string is less than, equal to, or greater than the second, +** respectively. A collating function must always return the same answer +** given the same inputs. If two or more collating functions are registered +** to the same collation name (using different eTextRep values) then all +** must give an equivalent answer when invoked with equivalent strings. +** The collating function must obey the following properties for all +** strings A, B, and C: +** +** <ol> +** <li> If A==B then B==A. +** <li> If A==B and B==C then A==C. +** <li> If A<B THEN B>A. +** <li> If A<B and B<C then A<C. +** </ol> +** +** If a collating function fails any of the above constraints and that +** collating function is registered and used, then the behavior of SQLite +** is undefined. +** +** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() +** with the addition that the xDestroy callback is invoked on pArg when +** the collating function is deleted. +** ^Collating functions are deleted when they are overridden by later +** calls to the collation creation functions or when the +** [database connection] is closed using [sqlite3_close()]. +** +** ^The xDestroy callback is <u>not</u> called if the +** sqlite3_create_collation_v2() function fails. Applications that invoke +** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should +** check the return code and dispose of the application data pointer +** themselves rather than expecting SQLite to deal with it for them. +** This is different from every other SQLite interface. The inconsistency +** is unfortunate but cannot be changed without breaking backwards +** compatibility. +** +** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. +*/ +int sqlite3_create_collation( + sqlite3*, + const char *zName, + int eTextRep, + void *pArg, + int(*xCompare)(void*,int,const void*,int,const void*) +); +int sqlite3_create_collation_v2( + sqlite3*, + const char *zName, + int eTextRep, + void *pArg, + int(*xCompare)(void*,int,const void*,int,const void*), + void(*xDestroy)(void*) +); +int sqlite3_create_collation16( + sqlite3*, + const void *zName, + int eTextRep, + void *pArg, + int(*xCompare)(void*,int,const void*,int,const void*) +); + +/* +** CAPI3REF: Collation Needed Callbacks +** METHOD: sqlite3 +** +** ^To avoid having to register all collation sequences before a database +** can be used, a single callback function may be registered with the +** [database connection] to be invoked whenever an undefined collation +** sequence is required. +** +** ^If the function is registered using the sqlite3_collation_needed() API, +** then it is passed the names of undefined collation sequences as strings +** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, +** the names are passed as UTF-16 in machine native byte order. +** ^A call to either function replaces the existing collation-needed callback. +** +** ^(When the callback is invoked, the first argument passed is a copy +** of the second argument to sqlite3_collation_needed() or +** sqlite3_collation_needed16(). The second argument is the database +** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], +** or [SQLITE_UTF16LE], indicating the most desirable form of the collation +** sequence function required. The fourth parameter is the name of the +** required collation sequence.)^ +** +** The callback function should register the desired collation using +** [sqlite3_create_collation()], [sqlite3_create_collation16()], or +** [sqlite3_create_collation_v2()]. +*/ +int sqlite3_collation_needed( + sqlite3*, + void*, + void(*)(void*,sqlite3*,int eTextRep,const char*) +); +int sqlite3_collation_needed16( + sqlite3*, + void*, + void(*)(void*,sqlite3*,int eTextRep,const void*) +); + +#ifdef SQLITE_ENABLE_CEROD +/* +** Specify the activation key for a CEROD database. Unless +** activated, none of the CEROD routines will work. +*/ +void sqlite3_activate_cerod( + const char *zPassPhrase /* Activation phrase */ +); +#endif + +/* +** CAPI3REF: Suspend Execution For A Short Time +** +** The sqlite3_sleep() function causes the current thread to suspend execution +** for at least a number of milliseconds specified in its parameter. +** +** If the operating system does not support sleep requests with +** millisecond time resolution, then the time will be rounded up to +** the nearest second. The number of milliseconds of sleep actually +** requested from the operating system is returned. +** +** ^SQLite implements this interface by calling the xSleep() +** method of the default [sqlite3_vfs] object. If the xSleep() method +** of the default VFS is not implemented correctly, or not implemented at +** all, then the behavior of sqlite3_sleep() may deviate from the description +** in the previous paragraphs. +*/ +int sqlite3_sleep(int); + +/* +** CAPI3REF: Name Of The Folder Holding Temporary Files +** +** ^(If this global variable is made to point to a string which is +** the name of a folder (a.k.a. directory), then all temporary files +** created by SQLite when using a built-in [sqlite3_vfs | VFS] +** will be placed in that directory.)^ ^If this variable +** is a NULL pointer, then SQLite performs a search for an appropriate +** temporary file directory. +** +** Applications are strongly discouraged from using this global variable. +** It is required to set a temporary folder on Windows Runtime (WinRT). +** But for all other platforms, it is highly recommended that applications +** neither read nor write this variable. This global variable is a relic +** that exists for backwards compatibility of legacy applications and should +** be avoided in new projects. +** +** It is not safe to read or modify this variable in more than one +** thread at a time. It is not safe to read or modify this variable +** if a [database connection] is being used at the same time in a separate +** thread. +** It is intended that this variable be set once +** as part of process initialization and before any SQLite interface +** routines have been called and that this variable remain unchanged +** thereafter. +** +** ^The [temp_store_directory pragma] may modify this variable and cause +** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, +** the [temp_store_directory pragma] always assumes that any string +** that this variable points to is held in memory obtained from +** [sqlite3_malloc] and the pragma may attempt to free that memory +** using [sqlite3_free]. +** Hence, if this variable is modified directly, either it should be +** made NULL or made to point to memory obtained from [sqlite3_malloc] +** or else the use of the [temp_store_directory pragma] should be avoided. +** Except when requested by the [temp_store_directory pragma], SQLite +** does not free the memory that sqlite3_temp_directory points to. If +** the application wants that memory to be freed, it must do +** so itself, taking care to only do so after all [database connection] +** objects have been destroyed. +** +** <b>Note to Windows Runtime users:</b> The temporary directory must be set +** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various +** features that require the use of temporary files may fail. Here is an +** example of how to do this using C++ with the Windows Runtime: +** +** <blockquote><pre> +** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> +** TemporaryFolder->Path->Data(); +** char zPathBuf[MAX_PATH + 1]; +** memset(zPathBuf, 0, sizeof(zPathBuf)); +** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), +** NULL, NULL); +** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); +** </pre></blockquote> +*/ +SQLITE_EXTERN char *sqlite3_temp_directory; + +/* +** CAPI3REF: Name Of The Folder Holding Database Files +** +** ^(If this global variable is made to point to a string which is +** the name of a folder (a.k.a. directory), then all database files +** specified with a relative pathname and created or accessed by +** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed +** to be relative to that directory.)^ ^If this variable is a NULL +** pointer, then SQLite assumes that all database files specified +** with a relative pathname are relative to the current directory +** for the process. Only the windows VFS makes use of this global +** variable; it is ignored by the unix VFS. +** +** Changing the value of this variable while a database connection is +** open can result in a corrupt database. +** +** It is not safe to read or modify this variable in more than one +** thread at a time. It is not safe to read or modify this variable +** if a [database connection] is being used at the same time in a separate +** thread. +** It is intended that this variable be set once +** as part of process initialization and before any SQLite interface +** routines have been called and that this variable remain unchanged +** thereafter. +** +** ^The [data_store_directory pragma] may modify this variable and cause +** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, +** the [data_store_directory pragma] always assumes that any string +** that this variable points to is held in memory obtained from +** [sqlite3_malloc] and the pragma may attempt to free that memory +** using [sqlite3_free]. +** Hence, if this variable is modified directly, either it should be +** made NULL or made to point to memory obtained from [sqlite3_malloc] +** or else the use of the [data_store_directory pragma] should be avoided. +*/ +SQLITE_EXTERN char *sqlite3_data_directory; + +/* +** CAPI3REF: Win32 Specific Interface +** +** These interfaces are available only on Windows. The +** [sqlite3_win32_set_directory] interface is used to set the value associated +** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to +** zValue, depending on the value of the type parameter. The zValue parameter +** should be NULL to cause the previous value to be freed via [sqlite3_free]; +** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] +** prior to being used. The [sqlite3_win32_set_directory] interface returns +** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, +** or [SQLITE_NOMEM] if memory could not be allocated. The value of the +** [sqlite3_data_directory] variable is intended to act as a replacement for +** the current directory on the sub-platforms of Win32 where that concept is +** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and +** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the +** sqlite3_win32_set_directory interface except the string parameter must be +** UTF-8 or UTF-16, respectively. +*/ +int sqlite3_win32_set_directory( + unsigned long type, /* Identifier for directory being set or reset */ + void *zValue /* New value for directory being set or reset */ +); +int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); +int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); + +/* +** CAPI3REF: Win32 Directory Types +** +** These macros are only available on Windows. They define the allowed values +** for the type argument to the [sqlite3_win32_set_directory] interface. +*/ +#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 +#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 + +/* +** CAPI3REF: Test For Auto-Commit Mode +** KEYWORDS: {autocommit mode} +** METHOD: sqlite3 +** +** ^The sqlite3_get_autocommit() interface returns non-zero or +** zero if the given database connection is or is not in autocommit mode, +** respectively. ^Autocommit mode is on by default. +** ^Autocommit mode is disabled by a [BEGIN] statement. +** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. +** +** If certain kinds of errors occur on a statement within a multi-statement +** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], +** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the +** transaction might be rolled back automatically. The only way to +** find out whether SQLite automatically rolled back the transaction after +** an error is to use this function. +** +** If another thread changes the autocommit status of the database +** connection while this routine is running, then the return value +** is undefined. +*/ +int sqlite3_get_autocommit(sqlite3*); + +/* +** CAPI3REF: Find The Database Handle Of A Prepared Statement +** METHOD: sqlite3_stmt +** +** ^The sqlite3_db_handle interface returns the [database connection] handle +** to which a [prepared statement] belongs. ^The [database connection] +** returned by sqlite3_db_handle is the same [database connection] +** that was the first argument +** to the [sqlite3_prepare_v2()] call (or its variants) that was used to +** create the statement in the first place. +*/ +sqlite3 *sqlite3_db_handle(sqlite3_stmt*); + +/* +** CAPI3REF: Return The Schema Name For A Database Connection +** METHOD: sqlite3 +** +** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name +** for the N-th database on database connection D, or a NULL pointer of N is +** out of range. An N value of 0 means the main database file. An N of 1 is +** the "temp" schema. Larger values of N correspond to various ATTACH-ed +** databases. +** +** Space to hold the string that is returned by sqlite3_db_name() is managed +** by SQLite itself. The string might be deallocated by any operation that +** changes the schema, including [ATTACH] or [DETACH] or calls to +** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that +** occur on a different thread. Applications that need to +** remember the string long-term should make their own copy. Applications that +** are accessing the same database connection simultaneously on multiple +** threads should mutex-protect calls to this API and should make their own +** private copy of the result prior to releasing the mutex. +*/ +const char *sqlite3_db_name(sqlite3 *db, int N); + +/* +** CAPI3REF: Return The Filename For A Database Connection +** METHOD: sqlite3 +** +** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename +** associated with database N of connection D. +** ^If there is no attached database N on the database +** connection D, or if database N is a temporary or in-memory database, then +** this function will return either a NULL pointer or an empty string. +** +** ^The string value returned by this routine is owned and managed by +** the database connection. ^The value will be valid until the database N +** is [DETACH]-ed or until the database connection closes. +** +** ^The filename returned by this function is the output of the +** xFullPathname method of the [VFS]. ^In other words, the filename +** will be an absolute pathname, even if the filename used +** to open the database originally was a URI or relative pathname. +** +** If the filename pointer returned by this routine is not NULL, then it +** can be used as the filename input parameter to these routines: +** <ul> +** <li> [sqlite3_uri_parameter()] +** <li> [sqlite3_uri_boolean()] +** <li> [sqlite3_uri_int64()] +** <li> [sqlite3_filename_database()] +** <li> [sqlite3_filename_journal()] +** <li> [sqlite3_filename_wal()] +** </ul> +*/ +sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); + +/* +** CAPI3REF: Determine if a database is read-only +** METHOD: sqlite3 +** +** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N +** of connection D is read-only, 0 if it is read/write, or -1 if N is not +** the name of a database on connection D. +*/ +int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); + +/* +** CAPI3REF: Determine the transaction state of a database +** METHOD: sqlite3 +** +** ^The sqlite3_txn_state(D,S) interface returns the current +** [transaction state] of schema S in database connection D. ^If S is NULL, +** then the highest transaction state of any schema on database connection D +** is returned. Transaction states are (in order of lowest to highest): +** <ol> +** <li value="0"> SQLITE_TXN_NONE +** <li value="1"> SQLITE_TXN_READ +** <li value="2"> SQLITE_TXN_WRITE +** </ol> +** ^If the S argument to sqlite3_txn_state(D,S) is not the name of +** a valid schema, then -1 is returned. +*/ +int sqlite3_txn_state(sqlite3*,const char *zSchema); + +/* +** CAPI3REF: Allowed return values from [sqlite3_txn_state()] +** KEYWORDS: {transaction state} +** +** These constants define the current transaction state of a database file. +** ^The [sqlite3_txn_state(D,S)] interface returns one of these +** constants in order to describe the transaction state of schema S +** in [database connection] D. +** +** <dl> +** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> +** <dd>The SQLITE_TXN_NONE state means that no transaction is currently +** pending.</dd> +** +** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> +** <dd>The SQLITE_TXN_READ state means that the database is currently +** in a read transaction. Content has been read from the database file +** but nothing in the database file has changed. The transaction state +** will advanced to SQLITE_TXN_WRITE if any changes occur and there are +** no other conflicting concurrent write transactions. The transaction +** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or +** [COMMIT].</dd> +** +** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> +** <dd>The SQLITE_TXN_WRITE state means that the database is currently +** in a write transaction. Content has been written to the database file +** but has not yet committed. The transaction state will change to +** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> +*/ +#define SQLITE_TXN_NONE 0 +#define SQLITE_TXN_READ 1 +#define SQLITE_TXN_WRITE 2 + +/* +** CAPI3REF: Find the next prepared statement +** METHOD: sqlite3 +** +** ^This interface returns a pointer to the next [prepared statement] after +** pStmt associated with the [database connection] pDb. ^If pStmt is NULL +** then this interface returns a pointer to the first prepared statement +** associated with the database connection pDb. ^If no prepared statement +** satisfies the conditions of this routine, it returns NULL. +** +** The [database connection] pointer D in a call to +** [sqlite3_next_stmt(D,S)] must refer to an open database +** connection and in particular must not be a NULL pointer. +*/ +sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Commit And Rollback Notification Callbacks +** METHOD: sqlite3 +** +** ^The sqlite3_commit_hook() interface registers a callback +** function to be invoked whenever a transaction is [COMMIT | committed]. +** ^Any callback set by a previous call to sqlite3_commit_hook() +** for the same database connection is overridden. +** ^The sqlite3_rollback_hook() interface registers a callback +** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. +** ^Any callback set by a previous call to sqlite3_rollback_hook() +** for the same database connection is overridden. +** ^The pArg argument is passed through to the callback. +** ^If the callback on a commit hook function returns non-zero, +** then the commit is converted into a rollback. +** +** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions +** return the P argument from the previous call of the same function +** on the same [database connection] D, or NULL for +** the first call for each function on D. +** +** The commit and rollback hook callbacks are not reentrant. +** The callback implementation must not do anything that will modify +** the database connection that invoked the callback. Any actions +** to modify the database connection must be deferred until after the +** completion of the [sqlite3_step()] call that triggered the commit +** or rollback hook in the first place. +** Note that running any other SQL statements, including SELECT statements, +** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify +** the database connections for the meaning of "modify" in this paragraph. +** +** ^Registering a NULL function disables the callback. +** +** ^When the commit hook callback routine returns zero, the [COMMIT] +** operation is allowed to continue normally. ^If the commit hook +** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. +** ^The rollback hook is invoked on a rollback that results from a commit +** hook returning non-zero, just as it would be with any other rollback. +** +** ^For the purposes of this API, a transaction is said to have been +** rolled back if an explicit "ROLLBACK" statement is executed, or +** an error or constraint causes an implicit rollback to occur. +** ^The rollback callback is not invoked if a transaction is +** automatically rolled back because the database connection is closed. +** +** See also the [sqlite3_update_hook()] interface. +*/ +void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); +void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); + +/* +** CAPI3REF: Autovacuum Compaction Amount Callback +** METHOD: sqlite3 +** +** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback +** function C that is invoked prior to each autovacuum of the database +** file. ^The callback is passed a copy of the generic data pointer (P), +** the schema-name of the attached database that is being autovacuumed, +** the size of the database file in pages, the number of free pages, +** and the number of bytes per page, respectively. The callback should +** return the number of free pages that should be removed by the +** autovacuum. ^If the callback returns zero, then no autovacuum happens. +** ^If the value returned is greater than or equal to the number of +** free pages, then a complete autovacuum happens. +** +** <p>^If there are multiple ATTACH-ed database files that are being +** modified as part of a transaction commit, then the autovacuum pages +** callback is invoked separately for each file. +** +** <p><b>The callback is not reentrant.</b> The callback function should +** not attempt to invoke any other SQLite interface. If it does, bad +** things may happen, including segmentation faults and corrupt database +** files. The callback function should be a simple function that +** does some arithmetic on its input parameters and returns a result. +** +** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional +** destructor for the P parameter. ^If X is not NULL, then X(P) is +** invoked whenever the database connection closes or when the callback +** is overwritten by another invocation of sqlite3_autovacuum_pages(). +** +** <p>^There is only one autovacuum pages callback per database connection. +** ^Each call to the sqlite3_autovacuum_pages() interface overrides all +** previous invocations for that database connection. ^If the callback +** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, +** then the autovacuum steps callback is cancelled. The return value +** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might +** be some other error code if something goes wrong. The current +** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other +** return codes might be added in future releases. +** +** <p>If no autovacuum pages callback is specified (the usual case) or +** a NULL pointer is provided for the callback, +** then the default behavior is to vacuum all free pages. So, in other +** words, the default behavior is the same as if the callback function +** were something like this: +** +** <blockquote><pre> +** unsigned int demonstration_autovac_pages_callback( +** void *pClientData, +** const char *zSchema, +** unsigned int nDbPage, +** unsigned int nFreePage, +** unsigned int nBytePerPage +** ){ +** return nFreePage; +** } +** </pre></blockquote> +*/ +int sqlite3_autovacuum_pages( + sqlite3 *db, + unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), + void*, + void(*)(void*) +); + + +/* +** CAPI3REF: Data Change Notification Callbacks +** METHOD: sqlite3 +** +** ^The sqlite3_update_hook() interface registers a callback function +** with the [database connection] identified by the first argument +** to be invoked whenever a row is updated, inserted or deleted in +** a [rowid table]. +** ^Any callback set by a previous call to this function +** for the same database connection is overridden. +** +** ^The second argument is a pointer to the function to invoke when a +** row is updated, inserted or deleted in a rowid table. +** ^The first argument to the callback is a copy of the third argument +** to sqlite3_update_hook(). +** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], +** or [SQLITE_UPDATE], depending on the operation that caused the callback +** to be invoked. +** ^The third and fourth arguments to the callback contain pointers to the +** database and table name containing the affected row. +** ^The final callback parameter is the [rowid] of the row. +** ^In the case of an update, this is the [rowid] after the update takes place. +** +** ^(The update hook is not invoked when internal system tables are +** modified (i.e. sqlite_sequence).)^ +** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. +** +** ^In the current implementation, the update hook +** is not invoked when conflicting rows are deleted because of an +** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook +** invoked when rows are deleted using the [truncate optimization]. +** The exceptions defined in this paragraph might change in a future +** release of SQLite. +** +** The update hook implementation must not do anything that will modify +** the database connection that invoked the update hook. Any actions +** to modify the database connection must be deferred until after the +** completion of the [sqlite3_step()] call that triggered the update hook. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +** ^The sqlite3_update_hook(D,C,P) function +** returns the P argument from the previous call +** on the same [database connection] D, or NULL for +** the first call on D. +** +** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], +** and [sqlite3_preupdate_hook()] interfaces. +*/ +void *sqlite3_update_hook( + sqlite3*, + void(*)(void *,int ,char const *,char const *,sqlite3_int64), + void* +); + +/* +** CAPI3REF: Enable Or Disable Shared Pager Cache +** +** ^(This routine enables or disables the sharing of the database cache +** and schema data structures between [database connection | connections] +** to the same database. Sharing is enabled if the argument is true +** and disabled if the argument is false.)^ +** +** This interface is omitted if SQLite is compiled with +** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] +** compile-time option is recommended because the +** [use of shared cache mode is discouraged]. +** +** ^Cache sharing is enabled and disabled for an entire process. +** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). +** In prior versions of SQLite, +** sharing was enabled or disabled for each thread separately. +** +** ^(The cache sharing mode set by this interface effects all subsequent +** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. +** Existing database connections continue to use the sharing mode +** that was in effect at the time they were opened.)^ +** +** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled +** successfully. An [error code] is returned otherwise.)^ +** +** ^Shared cache is disabled by default. It is recommended that it stay +** that way. In other words, do not use this routine. This interface +** continues to be provided for historical compatibility, but its use is +** discouraged. Any use of shared cache is discouraged. If shared cache +** must be used, it is recommended that shared cache only be enabled for +** individual database connections using the [sqlite3_open_v2()] interface +** with the [SQLITE_OPEN_SHAREDCACHE] flag. +** +** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 +** and will always return SQLITE_MISUSE. On those systems, +** shared cache mode should be enabled per-database connection via +** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. +** +** This interface is threadsafe on processors where writing a +** 32-bit integer is atomic. +** +** See Also: [SQLite Shared-Cache Mode] +*/ +int sqlite3_enable_shared_cache(int); + +/* +** CAPI3REF: Attempt To Free Heap Memory +** +** ^The sqlite3_release_memory() interface attempts to free N bytes +** of heap memory by deallocating non-essential memory allocations +** held by the database library. Memory used to cache database +** pages to improve performance is an example of non-essential memory. +** ^sqlite3_release_memory() returns the number of bytes actually freed, +** which might be more or less than the amount requested. +** ^The sqlite3_release_memory() routine is a no-op returning zero +** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. +** +** See also: [sqlite3_db_release_memory()] +*/ +int sqlite3_release_memory(int); + +/* +** CAPI3REF: Free Memory Used By A Database Connection +** METHOD: sqlite3 +** +** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap +** memory as possible from database connection D. Unlike the +** [sqlite3_release_memory()] interface, this interface is in effect even +** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is +** omitted. +** +** See also: [sqlite3_release_memory()] +*/ +int sqlite3_db_release_memory(sqlite3*); + +/* +** CAPI3REF: Impose A Limit On Heap Size +** +** These interfaces impose limits on the amount of heap memory that will be +** by all database connections within a single process. +** +** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the +** soft limit on the amount of heap memory that may be allocated by SQLite. +** ^SQLite strives to keep heap memory utilization below the soft heap +** limit by reducing the number of pages held in the page cache +** as heap memory usages approaches the limit. +** ^The soft heap limit is "soft" because even though SQLite strives to stay +** below the limit, it will exceed the limit rather than generate +** an [SQLITE_NOMEM] error. In other words, the soft heap limit +** is advisory only. +** +** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of +** N bytes on the amount of memory that will be allocated. ^The +** sqlite3_hard_heap_limit64(N) interface is similar to +** sqlite3_soft_heap_limit64(N) except that memory allocations will fail +** when the hard heap limit is reached. +** +** ^The return value from both sqlite3_soft_heap_limit64() and +** sqlite3_hard_heap_limit64() is the size of +** the heap limit prior to the call, or negative in the case of an +** error. ^If the argument N is negative +** then no change is made to the heap limit. Hence, the current +** size of heap limits can be determined by invoking +** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). +** +** ^Setting the heap limits to zero disables the heap limiter mechanism. +** +** ^The soft heap limit may not be greater than the hard heap limit. +** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) +** is invoked with a value of N that is greater than the hard heap limit, +** the soft heap limit is set to the value of the hard heap limit. +** ^The soft heap limit is automatically enabled whenever the hard heap +** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and +** the soft heap limit is outside the range of 1..N, then the soft heap +** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the +** hard heap limit is enabled makes the soft heap limit equal to the +** hard heap limit. +** +** The memory allocation limits can also be adjusted using +** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. +** +** ^(The heap limits are not enforced in the current implementation +** if one or more of following conditions are true: +** +** <ul> +** <li> The limit value is set to zero. +** <li> Memory accounting is disabled using a combination of the +** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and +** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. +** <li> An alternative page cache implementation is specified using +** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). +** <li> The page cache allocates from its own memory pool supplied +** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than +** from the heap. +** </ul>)^ +** +** The circumstances under which SQLite will enforce the heap limits may +** changes in future releases of SQLite. +*/ +sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); +sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); + +/* +** CAPI3REF: Deprecated Soft Heap Limit Interface +** DEPRECATED +** +** This is a deprecated version of the [sqlite3_soft_heap_limit64()] +** interface. This routine is provided for historical compatibility +** only. All new applications should use the +** [sqlite3_soft_heap_limit64()] interface rather than this one. +*/ +SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); + + +/* +** CAPI3REF: Extract Metadata About A Column Of A Table +** METHOD: sqlite3 +** +** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns +** information about column C of table T in database D +** on [database connection] X.)^ ^The sqlite3_table_column_metadata() +** interface returns SQLITE_OK and fills in the non-NULL pointers in +** the final five arguments with appropriate values if the specified +** column exists. ^The sqlite3_table_column_metadata() interface returns +** SQLITE_ERROR if the specified column does not exist. +** ^If the column-name parameter to sqlite3_table_column_metadata() is a +** NULL pointer, then this routine simply checks for the existence of the +** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it +** does not. If the table name parameter T in a call to +** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is +** undefined behavior. +** +** ^The column is identified by the second, third and fourth parameters to +** this function. ^(The second parameter is either the name of the database +** (i.e. "main", "temp", or an attached database) containing the specified +** table or NULL.)^ ^If it is NULL, then all attached databases are searched +** for the table using the same algorithm used by the database engine to +** resolve unqualified table references. +** +** ^The third and fourth parameters to this function are the table and column +** name of the desired column, respectively. +** +** ^Metadata is returned by writing to the memory locations passed as the 5th +** and subsequent parameters to this function. ^Any of these arguments may be +** NULL, in which case the corresponding element of metadata is omitted. +** +** ^(<blockquote> +** <table border="1"> +** <tr><th> Parameter <th> Output<br>Type <th> Description +** +** <tr><td> 5th <td> const char* <td> Data type +** <tr><td> 6th <td> const char* <td> Name of default collation sequence +** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint +** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY +** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] +** </table> +** </blockquote>)^ +** +** ^The memory pointed to by the character pointers returned for the +** declaration type and collation sequence is valid until the next +** call to any SQLite API function. +** +** ^If the specified table is actually a view, an [error code] is returned. +** +** ^If the specified column is "rowid", "oid" or "_rowid_" and the table +** is not a [WITHOUT ROWID] table and an +** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output +** parameters are set for the explicitly declared column. ^(If there is no +** [INTEGER PRIMARY KEY] column, then the outputs +** for the [rowid] are set as follows: +** +** <pre> +** data type: "INTEGER" +** collation sequence: "BINARY" +** not null: 0 +** primary key: 1 +** auto increment: 0 +** </pre>)^ +** +** ^This function causes all database schemas to be read from disk and +** parsed, if that has not already been done, and returns an error if +** any errors are encountered while loading the schema. +*/ +int sqlite3_table_column_metadata( + sqlite3 *db, /* Connection handle */ + const char *zDbName, /* Database name or NULL */ + const char *zTableName, /* Table name */ + const char *zColumnName, /* Column name */ + char const **pzDataType, /* OUTPUT: Declared data type */ + char const **pzCollSeq, /* OUTPUT: Collation sequence name */ + int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ + int *pPrimaryKey, /* OUTPUT: True if column part of PK */ + int *pAutoinc /* OUTPUT: True if column is auto-increment */ +); + +/* +** CAPI3REF: Load An Extension +** METHOD: sqlite3 +** +** ^This interface loads an SQLite extension library from the named file. +** +** ^The sqlite3_load_extension() interface attempts to load an +** [SQLite extension] library contained in the file zFile. If +** the file cannot be loaded directly, attempts are made to load +** with various operating-system specific extensions added. +** So for example, if "samplelib" cannot be loaded, then names like +** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might +** be tried also. +** +** ^The entry point is zProc. +** ^(zProc may be 0, in which case SQLite will try to come up with an +** entry point name on its own. It first tries "sqlite3_extension_init". +** If that does not work, it constructs a name "sqlite3_X_init" where the +** X is consists of the lower-case equivalent of all ASCII alphabetic +** characters in the filename from the last "/" to the first following +** "." and omitting any initial "lib".)^ +** ^The sqlite3_load_extension() interface returns +** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. +** ^If an error occurs and pzErrMsg is not 0, then the +** [sqlite3_load_extension()] interface shall attempt to +** fill *pzErrMsg with error message text stored in memory +** obtained from [sqlite3_malloc()]. The calling function +** should free this memory by calling [sqlite3_free()]. +** +** ^Extension loading must be enabled using +** [sqlite3_enable_load_extension()] or +** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) +** prior to calling this API, +** otherwise an error will be returned. +** +** <b>Security warning:</b> It is recommended that the +** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this +** interface. The use of the [sqlite3_enable_load_extension()] interface +** should be avoided. This will keep the SQL function [load_extension()] +** disabled and prevent SQL injections from giving attackers +** access to extension loading capabilities. +** +** See also the [load_extension() SQL function]. +*/ +int sqlite3_load_extension( + sqlite3 *db, /* Load the extension into this database connection */ + const char *zFile, /* Name of the shared library containing extension */ + const char *zProc, /* Entry point. Derived from zFile if 0 */ + char **pzErrMsg /* Put error message here if not 0 */ +); + +/* +** CAPI3REF: Enable Or Disable Extension Loading +** METHOD: sqlite3 +** +** ^So as not to open security holes in older applications that are +** unprepared to deal with [extension loading], and as a means of disabling +** [extension loading] while evaluating user-entered SQL, the following API +** is provided to turn the [sqlite3_load_extension()] mechanism on and off. +** +** ^Extension loading is off by default. +** ^Call the sqlite3_enable_load_extension() routine with onoff==1 +** to turn extension loading on and call it with onoff==0 to turn +** it back off again. +** +** ^This interface enables or disables both the C-API +** [sqlite3_load_extension()] and the SQL function [load_extension()]. +** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) +** to enable or disable only the C-API.)^ +** +** <b>Security warning:</b> It is recommended that extension loading +** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method +** rather than this interface, so the [load_extension()] SQL function +** remains disabled. This will prevent SQL injections from giving attackers +** access to extension loading capabilities. +*/ +int sqlite3_enable_load_extension(sqlite3 *db, int onoff); + +/* +** CAPI3REF: Automatically Load Statically Linked Extensions +** +** ^This interface causes the xEntryPoint() function to be invoked for +** each new [database connection] that is created. The idea here is that +** xEntryPoint() is the entry point for a statically linked [SQLite extension] +** that is to be automatically loaded into all new database connections. +** +** ^(Even though the function prototype shows that xEntryPoint() takes +** no arguments and returns void, SQLite invokes xEntryPoint() with three +** arguments and expects an integer result as if the signature of the +** entry point where as follows: +** +** <blockquote><pre> +** int xEntryPoint( +** sqlite3 *db, +** const char **pzErrMsg, +** const struct sqlite3_api_routines *pThunk +** ); +** </pre></blockquote>)^ +** +** If the xEntryPoint routine encounters an error, it should make *pzErrMsg +** point to an appropriate error message (obtained from [sqlite3_mprintf()]) +** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg +** is NULL before calling the xEntryPoint(). ^SQLite will invoke +** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any +** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], +** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. +** +** ^Calling sqlite3_auto_extension(X) with an entry point X that is already +** on the list of automatic extensions is a harmless no-op. ^No entry point +** will be called more than once for each database connection that is opened. +** +** See also: [sqlite3_reset_auto_extension()] +** and [sqlite3_cancel_auto_extension()] +*/ +int sqlite3_auto_extension(void(*xEntryPoint)(void)); + +/* +** CAPI3REF: Cancel Automatic Extension Loading +** +** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the +** initialization routine X that was registered using a prior call to +** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] +** routine returns 1 if initialization routine X was successfully +** unregistered and it returns 0 if X was not on the list of initialization +** routines. +*/ +int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); + +/* +** CAPI3REF: Reset Automatic Extension Loading +** +** ^This interface disables all automatic extensions previously +** registered using [sqlite3_auto_extension()]. +*/ +void sqlite3_reset_auto_extension(void); + +/* +** The interface to the virtual-table mechanism is currently considered +** to be experimental. The interface might change in incompatible ways. +** If this is a problem for you, do not use the interface at this time. +** +** When the virtual-table mechanism stabilizes, we will declare the +** interface fixed, support it indefinitely, and remove this comment. +*/ + +/* +** Structures used by the virtual table interface +*/ +typedef struct sqlite3_vtab sqlite3_vtab; +typedef struct sqlite3_index_info sqlite3_index_info; +typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; +typedef struct sqlite3_module sqlite3_module; + +/* +** CAPI3REF: Virtual Table Object +** KEYWORDS: sqlite3_module {virtual table module} +** +** This structure, sometimes called a "virtual table module", +** defines the implementation of a [virtual table]. +** This structure consists mostly of methods for the module. +** +** ^A virtual table module is created by filling in a persistent +** instance of this structure and passing a pointer to that instance +** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. +** ^The registration remains valid until it is replaced by a different +** module or until the [database connection] closes. The content +** of this structure must not change while it is registered with +** any database connection. +*/ +struct sqlite3_module { + int iVersion; + int (*xCreate)(sqlite3*, void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVTab, char**); + int (*xConnect)(sqlite3*, void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVTab, char**); + int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); + int (*xDisconnect)(sqlite3_vtab *pVTab); + int (*xDestroy)(sqlite3_vtab *pVTab); + int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); + int (*xClose)(sqlite3_vtab_cursor*); + int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, + int argc, sqlite3_value **argv); + int (*xNext)(sqlite3_vtab_cursor*); + int (*xEof)(sqlite3_vtab_cursor*); + int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); + int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); + int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); + int (*xBegin)(sqlite3_vtab *pVTab); + int (*xSync)(sqlite3_vtab *pVTab); + int (*xCommit)(sqlite3_vtab *pVTab); + int (*xRollback)(sqlite3_vtab *pVTab); + int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, + void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), + void **ppArg); + int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); + /* The methods above are in version 1 of the sqlite_module object. Those + ** below are for version 2 and greater. */ + int (*xSavepoint)(sqlite3_vtab *pVTab, int); + int (*xRelease)(sqlite3_vtab *pVTab, int); + int (*xRollbackTo)(sqlite3_vtab *pVTab, int); + /* The methods above are in versions 1 and 2 of the sqlite_module object. + ** Those below are for version 3 and greater. */ + int (*xShadowName)(const char*); +}; + +/* +** CAPI3REF: Virtual Table Indexing Information +** KEYWORDS: sqlite3_index_info +** +** The sqlite3_index_info structure and its substructures is used as part +** of the [virtual table] interface to +** pass information into and receive the reply from the [xBestIndex] +** method of a [virtual table module]. The fields under **Inputs** are the +** inputs to xBestIndex and are read-only. xBestIndex inserts its +** results into the **Outputs** fields. +** +** ^(The aConstraint[] array records WHERE clause constraints of the form: +** +** <blockquote>column OP expr</blockquote> +** +** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is +** stored in aConstraint[].op using one of the +** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ +** ^(The index of the column is stored in +** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the +** expr on the right-hand side can be evaluated (and thus the constraint +** is usable) and false if it cannot.)^ +** +** ^The optimizer automatically inverts terms of the form "expr OP column" +** and makes other simplifications to the WHERE clause in an attempt to +** get as many WHERE clause terms into the form shown above as possible. +** ^The aConstraint[] array only reports WHERE clause terms that are +** relevant to the particular virtual table being queried. +** +** ^Information about the ORDER BY clause is stored in aOrderBy[]. +** ^Each term of aOrderBy records a column of the ORDER BY clause. +** +** The colUsed field indicates which columns of the virtual table may be +** required by the current scan. Virtual table columns are numbered from +** zero in the order in which they appear within the CREATE TABLE statement +** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), +** the corresponding bit is set within the colUsed mask if the column may be +** required by SQLite. If the table has at least 64 columns and any column +** to the right of the first 63 is required, then bit 63 of colUsed is also +** set. In other words, column iCol may be required if the expression +** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to +** non-zero. +** +** The [xBestIndex] method must fill aConstraintUsage[] with information +** about what parameters to pass to xFilter. ^If argvIndex>0 then +** the right-hand side of the corresponding aConstraint[] is evaluated +** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit +** is true, then the constraint is assumed to be fully handled by the +** virtual table and might not be checked again by the byte code.)^ ^(The +** aConstraintUsage[].omit flag is an optimization hint. When the omit flag +** is left in its default setting of false, the constraint will always be +** checked separately in byte code. If the omit flag is change to true, then +** the constraint may or may not be checked in byte code. In other words, +** when the omit flag is true there is no guarantee that the constraint will +** not be checked again using byte code.)^ +** +** ^The idxNum and idxPtr values are recorded and passed into the +** [xFilter] method. +** ^[sqlite3_free()] is used to free idxPtr if and only if +** needToFreeIdxPtr is true. +** +** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in +** the correct order to satisfy the ORDER BY clause so that no separate +** sorting step is required. +** +** ^The estimatedCost value is an estimate of the cost of a particular +** strategy. A cost of N indicates that the cost of the strategy is similar +** to a linear scan of an SQLite table with N rows. A cost of log(N) +** indicates that the expense of the operation is similar to that of a +** binary search on a unique indexed field of an SQLite table with N rows. +** +** ^The estimatedRows value is an estimate of the number of rows that +** will be returned by the strategy. +** +** The xBestIndex method may optionally populate the idxFlags field with a +** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - +** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite +** assumes that the strategy may visit at most one row. +** +** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then +** SQLite also assumes that if a call to the xUpdate() method is made as +** part of the same statement to delete or update a virtual table row and the +** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback +** any database changes. In other words, if the xUpdate() returns +** SQLITE_CONSTRAINT, the database contents must be exactly as they were +** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not +** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by +** the xUpdate method are automatically rolled back by SQLite. +** +** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info +** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). +** If a virtual table extension is +** used with an SQLite version earlier than 3.8.2, the results of attempting +** to read or write the estimatedRows field are undefined (but are likely +** to include crashing the application). The estimatedRows field should +** therefore only be used if [sqlite3_libversion_number()] returns a +** value greater than or equal to 3008002. Similarly, the idxFlags field +** was added for [version 3.9.0] ([dateof:3.9.0]). +** It may therefore only be used if +** sqlite3_libversion_number() returns a value greater than or equal to +** 3009000. +*/ +struct sqlite3_index_info { + /* Inputs */ + int nConstraint; /* Number of entries in aConstraint */ + struct sqlite3_index_constraint { + int iColumn; /* Column constrained. -1 for ROWID */ + unsigned char op; /* Constraint operator */ + unsigned char usable; /* True if this constraint is usable */ + int iTermOffset; /* Used internally - xBestIndex should ignore */ + } *aConstraint; /* Table of WHERE clause constraints */ + int nOrderBy; /* Number of terms in the ORDER BY clause */ + struct sqlite3_index_orderby { + int iColumn; /* Column number */ + unsigned char desc; /* True for DESC. False for ASC. */ + } *aOrderBy; /* The ORDER BY clause */ + /* Outputs */ + struct sqlite3_index_constraint_usage { + int argvIndex; /* if >0, constraint is part of argv to xFilter */ + unsigned char omit; /* Do not code a test for this constraint */ + } *aConstraintUsage; + int idxNum; /* Number used to identify the index */ + char *idxStr; /* String, possibly obtained from sqlite3_malloc */ + int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ + int orderByConsumed; /* True if output is already ordered */ + double estimatedCost; /* Estimated cost of using this index */ + /* Fields below are only available in SQLite 3.8.2 and later */ + sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ + /* Fields below are only available in SQLite 3.9.0 and later */ + int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ + /* Fields below are only available in SQLite 3.10.0 and later */ + sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ +}; + +/* +** CAPI3REF: Virtual Table Scan Flags +** +** Virtual table implementations are allowed to set the +** [sqlite3_index_info].idxFlags field to some combination of +** these bits. +*/ +#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ + +/* +** CAPI3REF: Virtual Table Constraint Operator Codes +** +** These macros define the allowed values for the +** [sqlite3_index_info].aConstraint[].op field. Each value represents +** an operator that is part of a constraint term in the WHERE clause of +** a query that uses a [virtual table]. +** +** ^The left-hand operand of the operator is given by the corresponding +** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand +** operand is the rowid. +** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET +** operators have no left-hand operand, and so for those operators the +** corresponding aConstraint[].iColumn is meaningless and should not be +** used. +** +** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through +** value 255 are reserved to represent functions that are overloaded +** by the [xFindFunction|xFindFunction method] of the virtual table +** implementation. +** +** The right-hand operands for each constraint might be accessible using +** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand +** operand is only available if it appears as a single constant literal +** in the input SQL. If the right-hand operand is another column or an +** expression (even a constant expression) or a parameter, then the +** sqlite3_vtab_rhs_value() probably will not be able to extract it. +** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and +** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand +** and hence calls to sqlite3_vtab_rhs_value() for those operators will +** always return SQLITE_NOTFOUND. +** +** The collating sequence to be used for comparison can be found using +** the [sqlite3_vtab_collation()] interface. For most real-world virtual +** tables, the collating sequence of constraints does not matter (for example +** because the constraints are numeric) and so the sqlite3_vtab_collation() +** interface is no commonly needed. +*/ +#define SQLITE_INDEX_CONSTRAINT_EQ 2 +#define SQLITE_INDEX_CONSTRAINT_GT 4 +#define SQLITE_INDEX_CONSTRAINT_LE 8 +#define SQLITE_INDEX_CONSTRAINT_LT 16 +#define SQLITE_INDEX_CONSTRAINT_GE 32 +#define SQLITE_INDEX_CONSTRAINT_MATCH 64 +#define SQLITE_INDEX_CONSTRAINT_LIKE 65 +#define SQLITE_INDEX_CONSTRAINT_GLOB 66 +#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 +#define SQLITE_INDEX_CONSTRAINT_NE 68 +#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 +#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 +#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 +#define SQLITE_INDEX_CONSTRAINT_IS 72 +#define SQLITE_INDEX_CONSTRAINT_LIMIT 73 +#define SQLITE_INDEX_CONSTRAINT_OFFSET 74 +#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 + +/* +** CAPI3REF: Register A Virtual Table Implementation +** METHOD: sqlite3 +** +** ^These routines are used to register a new [virtual table module] name. +** ^Module names must be registered before +** creating a new [virtual table] using the module and before using a +** preexisting [virtual table] for the module. +** +** ^The module name is registered on the [database connection] specified +** by the first parameter. ^The name of the module is given by the +** second parameter. ^The third parameter is a pointer to +** the implementation of the [virtual table module]. ^The fourth +** parameter is an arbitrary client data pointer that is passed through +** into the [xCreate] and [xConnect] methods of the virtual table module +** when a new virtual table is be being created or reinitialized. +** +** ^The sqlite3_create_module_v2() interface has a fifth parameter which +** is a pointer to a destructor for the pClientData. ^SQLite will +** invoke the destructor function (if it is not NULL) when SQLite +** no longer needs the pClientData pointer. ^The destructor will also +** be invoked if the call to sqlite3_create_module_v2() fails. +** ^The sqlite3_create_module() +** interface is equivalent to sqlite3_create_module_v2() with a NULL +** destructor. +** +** ^If the third parameter (the pointer to the sqlite3_module object) is +** NULL then no new module is created and any existing modules with the +** same name are dropped. +** +** See also: [sqlite3_drop_modules()] +*/ +int sqlite3_create_module( + sqlite3 *db, /* SQLite connection to register module with */ + const char *zName, /* Name of the module */ + const sqlite3_module *p, /* Methods for the module */ + void *pClientData /* Client data for xCreate/xConnect */ +); +int sqlite3_create_module_v2( + sqlite3 *db, /* SQLite connection to register module with */ + const char *zName, /* Name of the module */ + const sqlite3_module *p, /* Methods for the module */ + void *pClientData, /* Client data for xCreate/xConnect */ + void(*xDestroy)(void*) /* Module destructor function */ +); + +/* +** CAPI3REF: Remove Unnecessary Virtual Table Implementations +** METHOD: sqlite3 +** +** ^The sqlite3_drop_modules(D,L) interface removes all virtual +** table modules from database connection D except those named on list L. +** The L parameter must be either NULL or a pointer to an array of pointers +** to strings where the array is terminated by a single NULL pointer. +** ^If the L parameter is NULL, then all virtual table modules are removed. +** +** See also: [sqlite3_create_module()] +*/ +int sqlite3_drop_modules( + sqlite3 *db, /* Remove modules from this connection */ + const char **azKeep /* Except, do not remove the ones named here */ +); + +/* +** CAPI3REF: Virtual Table Instance Object +** KEYWORDS: sqlite3_vtab +** +** Every [virtual table module] implementation uses a subclass +** of this object to describe a particular instance +** of the [virtual table]. Each subclass will +** be tailored to the specific needs of the module implementation. +** The purpose of this superclass is to define certain fields that are +** common to all module implementations. +** +** ^Virtual tables methods can set an error message by assigning a +** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should +** take care that any prior string is freed by a call to [sqlite3_free()] +** prior to assigning a new string to zErrMsg. ^After the error message +** is delivered up to the client application, the string will be automatically +** freed by sqlite3_free() and the zErrMsg field will be zeroed. +*/ +struct sqlite3_vtab { + const sqlite3_module *pModule; /* The module for this virtual table */ + int nRef; /* Number of open cursors */ + char *zErrMsg; /* Error message from sqlite3_mprintf() */ + /* Virtual table implementations will typically add additional fields */ +}; + +/* +** CAPI3REF: Virtual Table Cursor Object +** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} +** +** Every [virtual table module] implementation uses a subclass of the +** following structure to describe cursors that point into the +** [virtual table] and are used +** to loop through the virtual table. Cursors are created using the +** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed +** by the [sqlite3_module.xClose | xClose] method. Cursors are used +** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods +** of the module. Each module implementation will define +** the content of a cursor structure to suit its own needs. +** +** This superclass exists in order to define fields of the cursor that +** are common to all implementations. +*/ +struct sqlite3_vtab_cursor { + sqlite3_vtab *pVtab; /* Virtual table of this cursor */ + /* Virtual table implementations will typically add additional fields */ +}; + +/* +** CAPI3REF: Declare The Schema Of A Virtual Table +** +** ^The [xCreate] and [xConnect] methods of a +** [virtual table module] call this interface +** to declare the format (the names and datatypes of the columns) of +** the virtual tables they implement. +*/ +int sqlite3_declare_vtab(sqlite3*, const char *zSQL); + +/* +** CAPI3REF: Overload A Function For A Virtual Table +** METHOD: sqlite3 +** +** ^(Virtual tables can provide alternative implementations of functions +** using the [xFindFunction] method of the [virtual table module]. +** But global versions of those functions +** must exist in order to be overloaded.)^ +** +** ^(This API makes sure a global version of a function with a particular +** name and number of parameters exists. If no such function exists +** before this API is called, a new function is created.)^ ^The implementation +** of the new function always causes an exception to be thrown. So +** the new function is not good for anything by itself. Its only +** purpose is to be a placeholder function that can be overloaded +** by a [virtual table]. +*/ +int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); + +/* +** The interface to the virtual-table mechanism defined above (back up +** to a comment remarkably similar to this one) is currently considered +** to be experimental. The interface might change in incompatible ways. +** If this is a problem for you, do not use the interface at this time. +** +** When the virtual-table mechanism stabilizes, we will declare the +** interface fixed, support it indefinitely, and remove this comment. +*/ + +/* +** CAPI3REF: A Handle To An Open BLOB +** KEYWORDS: {BLOB handle} {BLOB handles} +** +** An instance of this object represents an open BLOB on which +** [sqlite3_blob_open | incremental BLOB I/O] can be performed. +** ^Objects of this type are created by [sqlite3_blob_open()] +** and destroyed by [sqlite3_blob_close()]. +** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces +** can be used to read or write small subsections of the BLOB. +** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. +*/ +typedef struct sqlite3_blob sqlite3_blob; + +/* +** CAPI3REF: Open A BLOB For Incremental I/O +** METHOD: sqlite3 +** CONSTRUCTOR: sqlite3_blob +** +** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located +** in row iRow, column zColumn, table zTable in database zDb; +** in other words, the same BLOB that would be selected by: +** +** <pre> +** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; +** </pre>)^ +** +** ^(Parameter zDb is not the filename that contains the database, but +** rather the symbolic name of the database. For attached databases, this is +** the name that appears after the AS keyword in the [ATTACH] statement. +** For the main database file, the database name is "main". For TEMP +** tables, the database name is "temp".)^ +** +** ^If the flags parameter is non-zero, then the BLOB is opened for read +** and write access. ^If the flags parameter is zero, the BLOB is opened for +** read-only access. +** +** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored +** in *ppBlob. Otherwise an [error code] is returned and, unless the error +** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided +** the API is not misused, it is always safe to call [sqlite3_blob_close()] +** on *ppBlob after this function it returns. +** +** This function fails with SQLITE_ERROR if any of the following are true: +** <ul> +** <li> ^(Database zDb does not exist)^, +** <li> ^(Table zTable does not exist within database zDb)^, +** <li> ^(Table zTable is a WITHOUT ROWID table)^, +** <li> ^(Column zColumn does not exist)^, +** <li> ^(Row iRow is not present in the table)^, +** <li> ^(The specified column of row iRow contains a value that is not +** a TEXT or BLOB value)^, +** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE +** constraint and the blob is being opened for read/write access)^, +** <li> ^([foreign key constraints | Foreign key constraints] are enabled, +** column zColumn is part of a [child key] definition and the blob is +** being opened for read/write access)^. +** </ul> +** +** ^Unless it returns SQLITE_MISUSE, this function sets the +** [database connection] error code and message accessible via +** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. +** +** A BLOB referenced by sqlite3_blob_open() may be read using the +** [sqlite3_blob_read()] interface and modified by using +** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a +** different row of the same table using the [sqlite3_blob_reopen()] +** interface. However, the column, table, or database of a [BLOB handle] +** cannot be changed after the [BLOB handle] is opened. +** +** ^(If the row that a BLOB handle points to is modified by an +** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects +** then the BLOB handle is marked as "expired". +** This is true if any column of the row is changed, even a column +** other than the one the BLOB handle is open on.)^ +** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for +** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. +** ^(Changes written into a BLOB prior to the BLOB expiring are not +** rolled back by the expiration of the BLOB. Such changes will eventually +** commit if the transaction continues to completion.)^ +** +** ^Use the [sqlite3_blob_bytes()] interface to determine the size of +** the opened blob. ^The size of a blob may not be changed by this +** interface. Use the [UPDATE] SQL command to change the size of a +** blob. +** +** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces +** and the built-in [zeroblob] SQL function may be used to create a +** zero-filled blob to read or write using the incremental-blob interface. +** +** To avoid a resource leak, every open [BLOB handle] should eventually +** be released by a call to [sqlite3_blob_close()]. +** +** See also: [sqlite3_blob_close()], +** [sqlite3_blob_reopen()], [sqlite3_blob_read()], +** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. +*/ +int sqlite3_blob_open( + sqlite3*, + const char *zDb, + const char *zTable, + const char *zColumn, + sqlite3_int64 iRow, + int flags, + sqlite3_blob **ppBlob +); + +/* +** CAPI3REF: Move a BLOB Handle to a New Row +** METHOD: sqlite3_blob +** +** ^This function is used to move an existing [BLOB handle] so that it points +** to a different row of the same database table. ^The new row is identified +** by the rowid value passed as the second argument. Only the row can be +** changed. ^The database, table and column on which the blob handle is open +** remain the same. Moving an existing [BLOB handle] to a new row is +** faster than closing the existing handle and opening a new one. +** +** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - +** it must exist and there must be either a blob or text value stored in +** the nominated column.)^ ^If the new row is not present in the table, or if +** it does not contain a blob or text value, or if another error occurs, an +** SQLite error code is returned and the blob handle is considered aborted. +** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or +** [sqlite3_blob_reopen()] on an aborted blob handle immediately return +** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle +** always returns zero. +** +** ^This function sets the database handle error code and message. +*/ +int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); + +/* +** CAPI3REF: Close A BLOB Handle +** DESTRUCTOR: sqlite3_blob +** +** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed +** unconditionally. Even if this routine returns an error code, the +** handle is still closed.)^ +** +** ^If the blob handle being closed was opened for read-write access, and if +** the database is in auto-commit mode and there are no other open read-write +** blob handles or active write statements, the current transaction is +** committed. ^If an error occurs while committing the transaction, an error +** code is returned and the transaction rolled back. +** +** Calling this function with an argument that is not a NULL pointer or an +** open blob handle results in undefined behaviour. ^Calling this routine +** with a null pointer (such as would be returned by a failed call to +** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function +** is passed a valid open blob handle, the values returned by the +** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. +*/ +int sqlite3_blob_close(sqlite3_blob *); + +/* +** CAPI3REF: Return The Size Of An Open BLOB +** METHOD: sqlite3_blob +** +** ^Returns the size in bytes of the BLOB accessible via the +** successfully opened [BLOB handle] in its only argument. ^The +** incremental blob I/O routines can only read or overwriting existing +** blob content; they cannot change the size of a blob. +** +** This routine only works on a [BLOB handle] which has been created +** by a prior successful call to [sqlite3_blob_open()] and which has not +** been closed by [sqlite3_blob_close()]. Passing any other pointer in +** to this routine results in undefined and probably undesirable behavior. +*/ +int sqlite3_blob_bytes(sqlite3_blob *); + +/* +** CAPI3REF: Read Data From A BLOB Incrementally +** METHOD: sqlite3_blob +** +** ^(This function is used to read data from an open [BLOB handle] into a +** caller-supplied buffer. N bytes of data are copied into buffer Z +** from the open BLOB, starting at offset iOffset.)^ +** +** ^If offset iOffset is less than N bytes from the end of the BLOB, +** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is +** less than zero, [SQLITE_ERROR] is returned and no data is read. +** ^The size of the blob (and hence the maximum value of N+iOffset) +** can be determined using the [sqlite3_blob_bytes()] interface. +** +** ^An attempt to read from an expired [BLOB handle] fails with an +** error code of [SQLITE_ABORT]. +** +** ^(On success, sqlite3_blob_read() returns SQLITE_OK. +** Otherwise, an [error code] or an [extended error code] is returned.)^ +** +** This routine only works on a [BLOB handle] which has been created +** by a prior successful call to [sqlite3_blob_open()] and which has not +** been closed by [sqlite3_blob_close()]. Passing any other pointer in +** to this routine results in undefined and probably undesirable behavior. +** +** See also: [sqlite3_blob_write()]. +*/ +int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); + +/* +** CAPI3REF: Write Data Into A BLOB Incrementally +** METHOD: sqlite3_blob +** +** ^(This function is used to write data into an open [BLOB handle] from a +** caller-supplied buffer. N bytes of data are copied from the buffer Z +** into the open BLOB, starting at offset iOffset.)^ +** +** ^(On success, sqlite3_blob_write() returns SQLITE_OK. +** Otherwise, an [error code] or an [extended error code] is returned.)^ +** ^Unless SQLITE_MISUSE is returned, this function sets the +** [database connection] error code and message accessible via +** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. +** +** ^If the [BLOB handle] passed as the first argument was not opened for +** writing (the flags parameter to [sqlite3_blob_open()] was zero), +** this function returns [SQLITE_READONLY]. +** +** This function may only modify the contents of the BLOB; it is +** not possible to increase the size of a BLOB using this API. +** ^If offset iOffset is less than N bytes from the end of the BLOB, +** [SQLITE_ERROR] is returned and no data is written. The size of the +** BLOB (and hence the maximum value of N+iOffset) can be determined +** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less +** than zero [SQLITE_ERROR] is returned and no data is written. +** +** ^An attempt to write to an expired [BLOB handle] fails with an +** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred +** before the [BLOB handle] expired are not rolled back by the +** expiration of the handle, though of course those changes might +** have been overwritten by the statement that expired the BLOB handle +** or by other independent statements. +** +** This routine only works on a [BLOB handle] which has been created +** by a prior successful call to [sqlite3_blob_open()] and which has not +** been closed by [sqlite3_blob_close()]. Passing any other pointer in +** to this routine results in undefined and probably undesirable behavior. +** +** See also: [sqlite3_blob_read()]. +*/ +int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); + +/* +** CAPI3REF: Virtual File System Objects +** +** A virtual filesystem (VFS) is an [sqlite3_vfs] object +** that SQLite uses to interact +** with the underlying operating system. Most SQLite builds come with a +** single default VFS that is appropriate for the host computer. +** New VFSes can be registered and existing VFSes can be unregistered. +** The following interfaces are provided. +** +** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. +** ^Names are case sensitive. +** ^Names are zero-terminated UTF-8 strings. +** ^If there is no match, a NULL pointer is returned. +** ^If zVfsName is NULL then the default VFS is returned. +** +** ^New VFSes are registered with sqlite3_vfs_register(). +** ^Each new VFS becomes the default VFS if the makeDflt flag is set. +** ^The same VFS can be registered multiple times without injury. +** ^To make an existing VFS into the default VFS, register it again +** with the makeDflt flag set. If two different VFSes with the +** same name are registered, the behavior is undefined. If a +** VFS is registered with a name that is NULL or an empty string, +** then the behavior is undefined. +** +** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. +** ^(If the default VFS is unregistered, another VFS is chosen as +** the default. The choice for the new VFS is arbitrary.)^ +*/ +sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); +int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); +int sqlite3_vfs_unregister(sqlite3_vfs*); + +/* +** CAPI3REF: Mutexes +** +** The SQLite core uses these routines for thread +** synchronization. Though they are intended for internal +** use by SQLite, code that links against SQLite is +** permitted to use any of these routines. +** +** The SQLite source code contains multiple implementations +** of these mutex routines. An appropriate implementation +** is selected automatically at compile-time. The following +** implementations are available in the SQLite core: +** +** <ul> +** <li> SQLITE_MUTEX_PTHREADS +** <li> SQLITE_MUTEX_W32 +** <li> SQLITE_MUTEX_NOOP +** </ul> +** +** The SQLITE_MUTEX_NOOP implementation is a set of routines +** that does no real locking and is appropriate for use in +** a single-threaded application. The SQLITE_MUTEX_PTHREADS and +** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix +** and Windows. +** +** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor +** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex +** implementation is included with the library. In this case the +** application must supply a custom mutex implementation using the +** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function +** before calling sqlite3_initialize() or any other public sqlite3_ +** function that calls sqlite3_initialize(). +** +** ^The sqlite3_mutex_alloc() routine allocates a new +** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() +** routine returns NULL if it is unable to allocate the requested +** mutex. The argument to sqlite3_mutex_alloc() must one of these +** integer constants: +** +** <ul> +** <li> SQLITE_MUTEX_FAST +** <li> SQLITE_MUTEX_RECURSIVE +** <li> SQLITE_MUTEX_STATIC_MAIN +** <li> SQLITE_MUTEX_STATIC_MEM +** <li> SQLITE_MUTEX_STATIC_OPEN +** <li> SQLITE_MUTEX_STATIC_PRNG +** <li> SQLITE_MUTEX_STATIC_LRU +** <li> SQLITE_MUTEX_STATIC_PMEM +** <li> SQLITE_MUTEX_STATIC_APP1 +** <li> SQLITE_MUTEX_STATIC_APP2 +** <li> SQLITE_MUTEX_STATIC_APP3 +** <li> SQLITE_MUTEX_STATIC_VFS1 +** <li> SQLITE_MUTEX_STATIC_VFS2 +** <li> SQLITE_MUTEX_STATIC_VFS3 +** </ul> +** +** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) +** cause sqlite3_mutex_alloc() to create +** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE +** is used but not necessarily so when SQLITE_MUTEX_FAST is used. +** The mutex implementation does not need to make a distinction +** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does +** not want to. SQLite will only request a recursive mutex in +** cases where it really needs one. If a faster non-recursive mutex +** implementation is available on the host platform, the mutex subsystem +** might return such a mutex in response to SQLITE_MUTEX_FAST. +** +** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other +** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return +** a pointer to a static preexisting mutex. ^Nine static mutexes are +** used by the current version of SQLite. Future versions of SQLite +** may add additional static mutexes. Static mutexes are for internal +** use by SQLite only. Applications that use SQLite mutexes should +** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or +** SQLITE_MUTEX_RECURSIVE. +** +** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST +** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() +** returns a different mutex on every call. ^For the static +** mutex types, the same mutex is returned on every call that has +** the same type number. +** +** ^The sqlite3_mutex_free() routine deallocates a previously +** allocated dynamic mutex. Attempting to deallocate a static +** mutex results in undefined behavior. +** +** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt +** to enter a mutex. ^If another thread is already within the mutex, +** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return +** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] +** upon successful entry. ^(Mutexes created using +** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. +** In such cases, the +** mutex must be exited an equal number of times before another thread +** can enter.)^ If the same thread tries to enter any mutex other +** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. +** +** ^(Some systems (for example, Windows 95) do not support the operation +** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() +** will always return SQLITE_BUSY. The SQLite core only ever uses +** sqlite3_mutex_try() as an optimization so this is acceptable +** behavior.)^ +** +** ^The sqlite3_mutex_leave() routine exits a mutex that was +** previously entered by the same thread. The behavior +** is undefined if the mutex is not currently entered by the +** calling thread or is not currently allocated. +** +** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or +** sqlite3_mutex_leave() is a NULL pointer, then all three routines +** behave as no-ops. +** +** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. +*/ +sqlite3_mutex *sqlite3_mutex_alloc(int); +void sqlite3_mutex_free(sqlite3_mutex*); +void sqlite3_mutex_enter(sqlite3_mutex*); +int sqlite3_mutex_try(sqlite3_mutex*); +void sqlite3_mutex_leave(sqlite3_mutex*); + +/* +** CAPI3REF: Mutex Methods Object +** +** An instance of this structure defines the low-level routines +** used to allocate and use mutexes. +** +** Usually, the default mutex implementations provided by SQLite are +** sufficient, however the application has the option of substituting a custom +** implementation for specialized deployments or systems for which SQLite +** does not provide a suitable implementation. In this case, the application +** creates and populates an instance of this structure to pass +** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. +** Additionally, an instance of this structure can be used as an +** output variable when querying the system for the current mutex +** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. +** +** ^The xMutexInit method defined by this structure is invoked as +** part of system initialization by the sqlite3_initialize() function. +** ^The xMutexInit routine is called by SQLite exactly once for each +** effective call to [sqlite3_initialize()]. +** +** ^The xMutexEnd method defined by this structure is invoked as +** part of system shutdown by the sqlite3_shutdown() function. The +** implementation of this method is expected to release all outstanding +** resources obtained by the mutex methods implementation, especially +** those obtained by the xMutexInit method. ^The xMutexEnd() +** interface is invoked exactly once for each call to [sqlite3_shutdown()]. +** +** ^(The remaining seven methods defined by this structure (xMutexAlloc, +** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and +** xMutexNotheld) implement the following interfaces (respectively): +** +** <ul> +** <li> [sqlite3_mutex_alloc()] </li> +** <li> [sqlite3_mutex_free()] </li> +** <li> [sqlite3_mutex_enter()] </li> +** <li> [sqlite3_mutex_try()] </li> +** <li> [sqlite3_mutex_leave()] </li> +** <li> [sqlite3_mutex_held()] </li> +** <li> [sqlite3_mutex_notheld()] </li> +** </ul>)^ +** +** The only difference is that the public sqlite3_XXX functions enumerated +** above silently ignore any invocations that pass a NULL pointer instead +** of a valid mutex handle. The implementations of the methods defined +** by this structure are not required to handle this case. The results +** of passing a NULL pointer instead of a valid mutex handle are undefined +** (i.e. it is acceptable to provide an implementation that segfaults if +** it is passed a NULL pointer). +** +** The xMutexInit() method must be threadsafe. It must be harmless to +** invoke xMutexInit() multiple times within the same process and without +** intervening calls to xMutexEnd(). Second and subsequent calls to +** xMutexInit() must be no-ops. +** +** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] +** and its associates). Similarly, xMutexAlloc() must not use SQLite memory +** allocation for a static mutex. ^However xMutexAlloc() may use SQLite +** memory allocation for a fast or recursive mutex. +** +** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is +** called, but only if the prior call to xMutexInit returned SQLITE_OK. +** If xMutexInit fails in any way, it is expected to clean up after itself +** prior to returning. +*/ +typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; +struct sqlite3_mutex_methods { + int (*xMutexInit)(void); + int (*xMutexEnd)(void); + sqlite3_mutex *(*xMutexAlloc)(int); + void (*xMutexFree)(sqlite3_mutex *); + void (*xMutexEnter)(sqlite3_mutex *); + int (*xMutexTry)(sqlite3_mutex *); + void (*xMutexLeave)(sqlite3_mutex *); + int (*xMutexHeld)(sqlite3_mutex *); + int (*xMutexNotheld)(sqlite3_mutex *); +}; + +/* +** CAPI3REF: Mutex Verification Routines +** +** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines +** are intended for use inside assert() statements. The SQLite core +** never uses these routines except inside an assert() and applications +** are advised to follow the lead of the core. The SQLite core only +** provides implementations for these routines when it is compiled +** with the SQLITE_DEBUG flag. External mutex implementations +** are only required to provide these routines if SQLITE_DEBUG is +** defined and if NDEBUG is not defined. +** +** These routines should return true if the mutex in their argument +** is held or not held, respectively, by the calling thread. +** +** The implementation is not required to provide versions of these +** routines that actually work. If the implementation does not provide working +** versions of these routines, it should at least provide stubs that always +** return true so that one does not get spurious assertion failures. +** +** If the argument to sqlite3_mutex_held() is a NULL pointer then +** the routine should return 1. This seems counter-intuitive since +** clearly the mutex cannot be held if it does not exist. But +** the reason the mutex does not exist is because the build is not +** using mutexes. And we do not want the assert() containing the +** call to sqlite3_mutex_held() to fail, so a non-zero return is +** the appropriate thing to do. The sqlite3_mutex_notheld() +** interface should also return 1 when given a NULL pointer. +*/ +#ifndef NDEBUG +int sqlite3_mutex_held(sqlite3_mutex*); +int sqlite3_mutex_notheld(sqlite3_mutex*); +#endif + +/* +** CAPI3REF: Mutex Types +** +** The [sqlite3_mutex_alloc()] interface takes a single argument +** which is one of these integer constants. +** +** The set of static mutexes may change from one SQLite release to the +** next. Applications that override the built-in mutex logic must be +** prepared to accommodate additional static mutexes. +*/ +#define SQLITE_MUTEX_FAST 0 +#define SQLITE_MUTEX_RECURSIVE 1 +#define SQLITE_MUTEX_STATIC_MAIN 2 +#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ +#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ +#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ +#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ +#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ +#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ +#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ +#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ +#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ +#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ +#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ +#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ +#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ + +/* Legacy compatibility: */ +#define SQLITE_MUTEX_STATIC_MASTER 2 + + +/* +** CAPI3REF: Retrieve the mutex for a database connection +** METHOD: sqlite3 +** +** ^This interface returns a pointer the [sqlite3_mutex] object that +** serializes access to the [database connection] given in the argument +** when the [threading mode] is Serialized. +** ^If the [threading mode] is Single-thread or Multi-thread then this +** routine returns a NULL pointer. +*/ +sqlite3_mutex *sqlite3_db_mutex(sqlite3*); + +/* +** CAPI3REF: Low-Level Control Of Database Files +** METHOD: sqlite3 +** KEYWORDS: {file control} +** +** ^The [sqlite3_file_control()] interface makes a direct call to the +** xFileControl method for the [sqlite3_io_methods] object associated +** with a particular database identified by the second argument. ^The +** name of the database is "main" for the main database or "temp" for the +** TEMP database, or the name that appears after the AS keyword for +** databases that are added using the [ATTACH] SQL command. +** ^A NULL pointer can be used in place of "main" to refer to the +** main database file. +** ^The third and fourth parameters to this routine +** are passed directly through to the second and third parameters of +** the xFileControl method. ^The return value of the xFileControl +** method becomes the return value of this routine. +** +** A few opcodes for [sqlite3_file_control()] are handled directly +** by the SQLite core and never invoke the +** sqlite3_io_methods.xFileControl method. +** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes +** a pointer to the underlying [sqlite3_file] object to be written into +** the space pointed to by the 4th parameter. The +** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns +** the [sqlite3_file] object associated with the journal file instead of +** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns +** a pointer to the underlying [sqlite3_vfs] object for the file. +** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter +** from the pager. +** +** ^If the second parameter (zDbName) does not match the name of any +** open database file, then SQLITE_ERROR is returned. ^This error +** code is not remembered and will not be recalled by [sqlite3_errcode()] +** or [sqlite3_errmsg()]. The underlying xFileControl method might +** also return SQLITE_ERROR. There is no way to distinguish between +** an incorrect zDbName and an SQLITE_ERROR return from the underlying +** xFileControl method. +** +** See also: [file control opcodes] +*/ +int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); + +/* +** CAPI3REF: Testing Interface +** +** ^The sqlite3_test_control() interface is used to read out internal +** state of SQLite and to inject faults into SQLite for testing +** purposes. ^The first parameter is an operation code that determines +** the number, meaning, and operation of all subsequent parameters. +** +** This interface is not for use by applications. It exists solely +** for verifying the correct operation of the SQLite library. Depending +** on how the SQLite library is compiled, this interface might not exist. +** +** The details of the operation codes, their meanings, the parameters +** they take, and what they do are all subject to change without notice. +** Unlike most of the SQLite API, this function is not guaranteed to +** operate consistently from one release to the next. +*/ +int sqlite3_test_control(int op, ...); + +/* +** CAPI3REF: Testing Interface Operation Codes +** +** These constants are the valid operation code parameters used +** as the first argument to [sqlite3_test_control()]. +** +** These parameters and their meanings are subject to change +** without notice. These values are for testing purposes only. +** Applications should not use any of these parameters or the +** [sqlite3_test_control()] interface. +*/ +#define SQLITE_TESTCTRL_FIRST 5 +#define SQLITE_TESTCTRL_PRNG_SAVE 5 +#define SQLITE_TESTCTRL_PRNG_RESTORE 6 +#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ +#define SQLITE_TESTCTRL_BITVEC_TEST 8 +#define SQLITE_TESTCTRL_FAULT_INSTALL 9 +#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 +#define SQLITE_TESTCTRL_PENDING_BYTE 11 +#define SQLITE_TESTCTRL_ASSERT 12 +#define SQLITE_TESTCTRL_ALWAYS 13 +#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ +#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 +#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ +#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ +#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 +#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 +#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ +#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 +#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 +#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 +#define SQLITE_TESTCTRL_BYTEORDER 22 +#define SQLITE_TESTCTRL_ISINIT 23 +#define SQLITE_TESTCTRL_SORTER_MMAP 24 +#define SQLITE_TESTCTRL_IMPOSTER 25 +#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 +#define SQLITE_TESTCTRL_RESULT_INTREAL 27 +#define SQLITE_TESTCTRL_PRNG_SEED 28 +#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 +#define SQLITE_TESTCTRL_SEEK_COUNT 30 +#define SQLITE_TESTCTRL_TRACEFLAGS 31 +#define SQLITE_TESTCTRL_TUNE 32 +#define SQLITE_TESTCTRL_LOGEST 33 +#define SQLITE_TESTCTRL_LAST 33 /* Largest TESTCTRL */ + +/* +** CAPI3REF: SQL Keyword Checking +** +** These routines provide access to the set of SQL language keywords +** recognized by SQLite. Applications can uses these routines to determine +** whether or not a specific identifier needs to be escaped (for example, +** by enclosing in double-quotes) so as not to confuse the parser. +** +** The sqlite3_keyword_count() interface returns the number of distinct +** keywords understood by SQLite. +** +** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and +** makes *Z point to that keyword expressed as UTF8 and writes the number +** of bytes in the keyword into *L. The string that *Z points to is not +** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns +** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z +** or L are NULL or invalid pointers then calls to +** sqlite3_keyword_name(N,Z,L) result in undefined behavior. +** +** The sqlite3_keyword_check(Z,L) interface checks to see whether or not +** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero +** if it is and zero if not. +** +** The parser used by SQLite is forgiving. It is often possible to use +** a keyword as an identifier as long as such use does not result in a +** parsing ambiguity. For example, the statement +** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and +** creates a new table named "BEGIN" with three columns named +** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid +** using keywords as identifiers. Common techniques used to avoid keyword +** name collisions include: +** <ul> +** <li> Put all identifier names inside double-quotes. This is the official +** SQL way to escape identifier names. +** <li> Put identifier names inside [...]. This is not standard SQL, +** but it is what SQL Server does and so lots of programmers use this +** technique. +** <li> Begin every identifier with the letter "Z" as no SQL keywords start +** with "Z". +** <li> Include a digit somewhere in every identifier name. +** </ul> +** +** Note that the number of keywords understood by SQLite can depend on +** compile-time options. For example, "VACUUM" is not a keyword if +** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, +** new keywords may be added to future releases of SQLite. +*/ +int sqlite3_keyword_count(void); +int sqlite3_keyword_name(int,const char**,int*); +int sqlite3_keyword_check(const char*,int); + +/* +** CAPI3REF: Dynamic String Object +** KEYWORDS: {dynamic string} +** +** An instance of the sqlite3_str object contains a dynamically-sized +** string under construction. +** +** The lifecycle of an sqlite3_str object is as follows: +** <ol> +** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. +** <li> ^Text is appended to the sqlite3_str object using various +** methods, such as [sqlite3_str_appendf()]. +** <li> ^The sqlite3_str object is destroyed and the string it created +** is returned using the [sqlite3_str_finish()] interface. +** </ol> +*/ +typedef struct sqlite3_str sqlite3_str; + +/* +** CAPI3REF: Create A New Dynamic String Object +** CONSTRUCTOR: sqlite3_str +** +** ^The [sqlite3_str_new(D)] interface allocates and initializes +** a new [sqlite3_str] object. To avoid memory leaks, the object returned by +** [sqlite3_str_new()] must be freed by a subsequent call to +** [sqlite3_str_finish(X)]. +** +** ^The [sqlite3_str_new(D)] interface always returns a pointer to a +** valid [sqlite3_str] object, though in the event of an out-of-memory +** error the returned object might be a special singleton that will +** silently reject new text, always return SQLITE_NOMEM from +** [sqlite3_str_errcode()], always return 0 for +** [sqlite3_str_length()], and always return NULL from +** [sqlite3_str_finish(X)]. It is always safe to use the value +** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter +** to any of the other [sqlite3_str] methods. +** +** The D parameter to [sqlite3_str_new(D)] may be NULL. If the +** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum +** length of the string contained in the [sqlite3_str] object will be +** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead +** of [SQLITE_MAX_LENGTH]. +*/ +sqlite3_str *sqlite3_str_new(sqlite3*); + +/* +** CAPI3REF: Finalize A Dynamic String +** DESTRUCTOR: sqlite3_str +** +** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X +** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] +** that contains the constructed string. The calling application should +** pass the returned value to [sqlite3_free()] to avoid a memory leak. +** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any +** errors were encountered during construction of the string. ^The +** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the +** string in [sqlite3_str] object X is zero bytes long. +*/ +char *sqlite3_str_finish(sqlite3_str*); + +/* +** CAPI3REF: Add Content To A Dynamic String +** METHOD: sqlite3_str +** +** These interfaces add content to an sqlite3_str object previously obtained +** from [sqlite3_str_new()]. +** +** ^The [sqlite3_str_appendf(X,F,...)] and +** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] +** functionality of SQLite to append formatted text onto the end of +** [sqlite3_str] object X. +** +** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S +** onto the end of the [sqlite3_str] object X. N must be non-negative. +** S must contain at least N non-zero bytes of content. To append a +** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] +** method instead. +** +** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of +** zero-terminated string S onto the end of [sqlite3_str] object X. +** +** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the +** single-byte character C onto the end of [sqlite3_str] object X. +** ^This method can be used, for example, to add whitespace indentation. +** +** ^The [sqlite3_str_reset(X)] method resets the string under construction +** inside [sqlite3_str] object X back to zero bytes in length. +** +** These methods do not return a result code. ^If an error occurs, that fact +** is recorded in the [sqlite3_str] object and can be recovered by a +** subsequent call to [sqlite3_str_errcode(X)]. +*/ +void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); +void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); +void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); +void sqlite3_str_appendall(sqlite3_str*, const char *zIn); +void sqlite3_str_appendchar(sqlite3_str*, int N, char C); +void sqlite3_str_reset(sqlite3_str*); + +/* +** CAPI3REF: Status Of A Dynamic String +** METHOD: sqlite3_str +** +** These interfaces return the current status of an [sqlite3_str] object. +** +** ^If any prior errors have occurred while constructing the dynamic string +** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return +** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns +** [SQLITE_NOMEM] following any out-of-memory error, or +** [SQLITE_TOOBIG] if the size of the dynamic string exceeds +** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. +** +** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, +** of the dynamic string under construction in [sqlite3_str] object X. +** ^The length returned by [sqlite3_str_length(X)] does not include the +** zero-termination byte. +** +** ^The [sqlite3_str_value(X)] method returns a pointer to the current +** content of the dynamic string under construction in X. The value +** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X +** and might be freed or altered by any subsequent method on the same +** [sqlite3_str] object. Applications must not used the pointer returned +** [sqlite3_str_value(X)] after any subsequent method call on the same +** object. ^Applications may change the content of the string returned +** by [sqlite3_str_value(X)] as long as they do not write into any bytes +** outside the range of 0 to [sqlite3_str_length(X)] and do not read or +** write any byte after any subsequent sqlite3_str method call. +*/ +int sqlite3_str_errcode(sqlite3_str*); +int sqlite3_str_length(sqlite3_str*); +char *sqlite3_str_value(sqlite3_str*); + +/* +** CAPI3REF: SQLite Runtime Status +** +** ^These interfaces are used to retrieve runtime status information +** about the performance of SQLite, and optionally to reset various +** highwater marks. ^The first argument is an integer code for +** the specific parameter to measure. ^(Recognized integer codes +** are of the form [status parameters | SQLITE_STATUS_...].)^ +** ^The current value of the parameter is returned into *pCurrent. +** ^The highest recorded value is returned in *pHighwater. ^If the +** resetFlag is true, then the highest record value is reset after +** *pHighwater is written. ^(Some parameters do not record the highest +** value. For those parameters +** nothing is written into *pHighwater and the resetFlag is ignored.)^ +** ^(Other parameters record only the highwater mark and not the current +** value. For these latter parameters nothing is written into *pCurrent.)^ +** +** ^The sqlite3_status() and sqlite3_status64() routines return +** SQLITE_OK on success and a non-zero [error code] on failure. +** +** If either the current value or the highwater mark is too large to +** be represented by a 32-bit integer, then the values returned by +** sqlite3_status() are undefined. +** +** See also: [sqlite3_db_status()] +*/ +int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); +int sqlite3_status64( + int op, + sqlite3_int64 *pCurrent, + sqlite3_int64 *pHighwater, + int resetFlag +); + + +/* +** CAPI3REF: Status Parameters +** KEYWORDS: {status parameters} +** +** These integer constants designate various run-time status parameters +** that can be returned by [sqlite3_status()]. +** +** <dl> +** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> +** <dd>This parameter is the current amount of memory checked out +** using [sqlite3_malloc()], either directly or indirectly. The +** figure includes calls made to [sqlite3_malloc()] by the application +** and internal memory usage by the SQLite library. Auxiliary page-cache +** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in +** this parameter. The amount returned is the sum of the allocation +** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ +** +** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> +** <dd>This parameter records the largest memory allocation request +** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their +** internal equivalents). Only the value returned in the +** *pHighwater parameter to [sqlite3_status()] is of interest. +** The value written into the *pCurrent parameter is undefined.</dd>)^ +** +** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> +** <dd>This parameter records the number of separate memory allocations +** currently checked out.</dd>)^ +** +** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> +** <dd>This parameter returns the number of pages used out of the +** [pagecache memory allocator] that was configured using +** [SQLITE_CONFIG_PAGECACHE]. The +** value returned is in pages, not in bytes.</dd>)^ +** +** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] +** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> +** <dd>This parameter returns the number of bytes of page cache +** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] +** buffer and where forced to overflow to [sqlite3_malloc()]. The +** returned value includes allocations that overflowed because they +** where too large (they were larger than the "sz" parameter to +** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because +** no space was left in the page cache.</dd>)^ +** +** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> +** <dd>This parameter records the largest memory allocation request +** handed to the [pagecache memory allocator]. Only the value returned in the +** *pHighwater parameter to [sqlite3_status()] is of interest. +** The value written into the *pCurrent parameter is undefined.</dd>)^ +** +** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> +** <dd>No longer used.</dd> +** +** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> +** <dd>No longer used.</dd> +** +** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> +** <dd>No longer used.</dd> +** +** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> +** <dd>The *pHighwater parameter records the deepest parser stack. +** The *pCurrent value is undefined. The *pHighwater value is only +** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ +** </dl> +** +** New status parameters may be added from time to time. +*/ +#define SQLITE_STATUS_MEMORY_USED 0 +#define SQLITE_STATUS_PAGECACHE_USED 1 +#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 +#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ +#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ +#define SQLITE_STATUS_MALLOC_SIZE 5 +#define SQLITE_STATUS_PARSER_STACK 6 +#define SQLITE_STATUS_PAGECACHE_SIZE 7 +#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ +#define SQLITE_STATUS_MALLOC_COUNT 9 + +/* +** CAPI3REF: Database Connection Status +** METHOD: sqlite3 +** +** ^This interface is used to retrieve runtime status information +** about a single [database connection]. ^The first argument is the +** database connection object to be interrogated. ^The second argument +** is an integer constant, taken from the set of +** [SQLITE_DBSTATUS options], that +** determines the parameter to interrogate. The set of +** [SQLITE_DBSTATUS options] is likely +** to grow in future releases of SQLite. +** +** ^The current value of the requested parameter is written into *pCur +** and the highest instantaneous value is written into *pHiwtr. ^If +** the resetFlg is true, then the highest instantaneous value is +** reset back down to the current value. +** +** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a +** non-zero [error code] on failure. +** +** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. +*/ +int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); + +/* +** CAPI3REF: Status Parameters for database connections +** KEYWORDS: {SQLITE_DBSTATUS options} +** +** These constants are the available integer "verbs" that can be passed as +** the second argument to the [sqlite3_db_status()] interface. +** +** New verbs may be added in future releases of SQLite. Existing verbs +** might be discontinued. Applications should check the return code from +** [sqlite3_db_status()] to make sure that the call worked. +** The [sqlite3_db_status()] interface will return a non-zero error code +** if a discontinued or unsupported verb is invoked. +** +** <dl> +** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> +** <dd>This parameter returns the number of lookaside memory slots currently +** checked out.</dd>)^ +** +** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> +** <dd>This parameter returns the number of malloc attempts that were +** satisfied using lookaside memory. Only the high-water value is meaningful; +** the current value is always zero.)^ +** +** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] +** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> +** <dd>This parameter returns the number malloc attempts that might have +** been satisfied using lookaside memory but failed due to the amount of +** memory requested being larger than the lookaside slot size. +** Only the high-water value is meaningful; +** the current value is always zero.)^ +** +** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] +** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> +** <dd>This parameter returns the number malloc attempts that might have +** been satisfied using lookaside memory but failed due to all lookaside +** memory already being in use. +** Only the high-water value is meaningful; +** the current value is always zero.)^ +** +** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> +** <dd>This parameter returns the approximate number of bytes of heap +** memory used by all pager caches associated with the database connection.)^ +** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. +** +** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] +** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> +** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a +** pager cache is shared between two or more connections the bytes of heap +** memory used by that pager cache is divided evenly between the attached +** connections.)^ In other words, if none of the pager caches associated +** with the database connection are shared, this request returns the same +** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are +** shared, the value returned by this call will be smaller than that returned +** by DBSTATUS_CACHE_USED. ^The highwater mark associated with +** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. +** +** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> +** <dd>This parameter returns the approximate number of bytes of heap +** memory used to store the schema for all databases associated +** with the connection - main, temp, and any [ATTACH]-ed databases.)^ +** ^The full amount of memory used by the schemas is reported, even if the +** schema memory is shared with other database connections due to +** [shared cache mode] being enabled. +** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. +** +** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> +** <dd>This parameter returns the approximate number of bytes of heap +** and lookaside memory used by all prepared statements associated with +** the database connection.)^ +** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. +** </dd> +** +** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> +** <dd>This parameter returns the number of pager cache hits that have +** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT +** is always 0. +** </dd> +** +** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> +** <dd>This parameter returns the number of pager cache misses that have +** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS +** is always 0. +** </dd> +** +** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> +** <dd>This parameter returns the number of dirty cache entries that have +** been written to disk. Specifically, the number of pages written to the +** wal file in wal mode databases, or the number of pages written to the +** database file in rollback mode databases. Any pages written as part of +** transaction rollback or database recovery operations are not included. +** If an IO or other error occurs while writing a page to disk, the effect +** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The +** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. +** </dd> +** +** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> +** <dd>This parameter returns the number of dirty cache entries that have +** been written to disk in the middle of a transaction due to the page +** cache overflowing. Transactions are more efficient if they are written +** to disk all at once. When pages spill mid-transaction, that introduces +** additional overhead. This parameter can be used help identify +** inefficiencies that can be resolved by increasing the cache size. +** </dd> +** +** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> +** <dd>This parameter returns zero for the current value if and only if +** all foreign key constraints (deferred or immediate) have been +** resolved.)^ ^The highwater mark is always 0. +** </dd> +** </dl> +*/ +#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 +#define SQLITE_DBSTATUS_CACHE_USED 1 +#define SQLITE_DBSTATUS_SCHEMA_USED 2 +#define SQLITE_DBSTATUS_STMT_USED 3 +#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 +#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 +#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 +#define SQLITE_DBSTATUS_CACHE_HIT 7 +#define SQLITE_DBSTATUS_CACHE_MISS 8 +#define SQLITE_DBSTATUS_CACHE_WRITE 9 +#define SQLITE_DBSTATUS_DEFERRED_FKS 10 +#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 +#define SQLITE_DBSTATUS_CACHE_SPILL 12 +#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ + + +/* +** CAPI3REF: Prepared Statement Status +** METHOD: sqlite3_stmt +** +** ^(Each prepared statement maintains various +** [SQLITE_STMTSTATUS counters] that measure the number +** of times it has performed specific operations.)^ These counters can +** be used to monitor the performance characteristics of the prepared +** statements. For example, if the number of table steps greatly exceeds +** the number of table searches or result rows, that would tend to indicate +** that the prepared statement is using a full table scan rather than +** an index. +** +** ^(This interface is used to retrieve and reset counter values from +** a [prepared statement]. The first argument is the prepared statement +** object to be interrogated. The second argument +** is an integer code for a specific [SQLITE_STMTSTATUS counter] +** to be interrogated.)^ +** ^The current value of the requested counter is returned. +** ^If the resetFlg is true, then the counter is reset to zero after this +** interface call returns. +** +** See also: [sqlite3_status()] and [sqlite3_db_status()]. +*/ +int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); + +/* +** CAPI3REF: Status Parameters for prepared statements +** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} +** +** These preprocessor macros define integer codes that name counter +** values associated with the [sqlite3_stmt_status()] interface. +** The meanings of the various counters are as follows: +** +** <dl> +** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> +** <dd>^This is the number of times that SQLite has stepped forward in +** a table as part of a full table scan. Large numbers for this counter +** may indicate opportunities for performance improvement through +** careful use of indices.</dd> +** +** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> +** <dd>^This is the number of sort operations that have occurred. +** A non-zero value in this counter may indicate an opportunity to +** improvement performance through careful use of indices.</dd> +** +** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> +** <dd>^This is the number of rows inserted into transient indices that +** were created automatically in order to help joins run faster. +** A non-zero value in this counter may indicate an opportunity to +** improvement performance by adding permanent indices that do not +** need to be reinitialized each time the statement is run.</dd> +** +** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> +** <dd>^This is the number of virtual machine operations executed +** by the prepared statement if that number is less than or equal +** to 2147483647. The number of virtual machine operations can be +** used as a proxy for the total work done by the prepared statement. +** If the number of virtual machine operations exceeds 2147483647 +** then the value returned by this statement status code is undefined. +** +** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> +** <dd>^This is the number of times that the prepare statement has been +** automatically regenerated due to schema changes or changes to +** [bound parameters] that might affect the query plan. +** +** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> +** <dd>^This is the number of times that the prepared statement has +** been run. A single "run" for the purposes of this counter is one +** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. +** The counter is incremented on the first [sqlite3_step()] call of each +** cycle. +** +** [[SQLITE_STMTSTATUS_FILTER_MISS]] +** [[SQLITE_STMTSTATUS_FILTER HIT]] +** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> +** SQLITE_STMTSTATUS_FILTER_MISS</dt> +** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join +** step was bypassed because a Bloom filter returned not-found. The +** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of +** times that the Bloom filter returned a find, and thus the join step +** had to be processed as normal. +** +** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> +** <dd>^This is the approximate number of bytes of heap memory +** used to store the prepared statement. ^This value is not actually +** a counter, and so the resetFlg parameter to sqlite3_stmt_status() +** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. +** </dd> +** </dl> +*/ +#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 +#define SQLITE_STMTSTATUS_SORT 2 +#define SQLITE_STMTSTATUS_AUTOINDEX 3 +#define SQLITE_STMTSTATUS_VM_STEP 4 +#define SQLITE_STMTSTATUS_REPREPARE 5 +#define SQLITE_STMTSTATUS_RUN 6 +#define SQLITE_STMTSTATUS_FILTER_MISS 7 +#define SQLITE_STMTSTATUS_FILTER_HIT 8 +#define SQLITE_STMTSTATUS_MEMUSED 99 + +/* +** CAPI3REF: Custom Page Cache Object +** +** The sqlite3_pcache type is opaque. It is implemented by +** the pluggable module. The SQLite core has no knowledge of +** its size or internal structure and never deals with the +** sqlite3_pcache object except by holding and passing pointers +** to the object. +** +** See [sqlite3_pcache_methods2] for additional information. +*/ +typedef struct sqlite3_pcache sqlite3_pcache; + +/* +** CAPI3REF: Custom Page Cache Object +** +** The sqlite3_pcache_page object represents a single page in the +** page cache. The page cache will allocate instances of this +** object. Various methods of the page cache use pointers to instances +** of this object as parameters or as their return value. +** +** See [sqlite3_pcache_methods2] for additional information. +*/ +typedef struct sqlite3_pcache_page sqlite3_pcache_page; +struct sqlite3_pcache_page { + void *pBuf; /* The content of the page */ + void *pExtra; /* Extra information associated with the page */ +}; + +/* +** CAPI3REF: Application Defined Page Cache. +** KEYWORDS: {page cache} +** +** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can +** register an alternative page cache implementation by passing in an +** instance of the sqlite3_pcache_methods2 structure.)^ +** In many applications, most of the heap memory allocated by +** SQLite is used for the page cache. +** By implementing a +** custom page cache using this API, an application can better control +** the amount of memory consumed by SQLite, the way in which +** that memory is allocated and released, and the policies used to +** determine exactly which parts of a database file are cached and for +** how long. +** +** The alternative page cache mechanism is an +** extreme measure that is only needed by the most demanding applications. +** The built-in page cache is recommended for most uses. +** +** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an +** internal buffer by SQLite within the call to [sqlite3_config]. Hence +** the application may discard the parameter after the call to +** [sqlite3_config()] returns.)^ +** +** [[the xInit() page cache method]] +** ^(The xInit() method is called once for each effective +** call to [sqlite3_initialize()])^ +** (usually only once during the lifetime of the process). ^(The xInit() +** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ +** The intent of the xInit() method is to set up global data structures +** required by the custom page cache implementation. +** ^(If the xInit() method is NULL, then the +** built-in default page cache is used instead of the application defined +** page cache.)^ +** +** [[the xShutdown() page cache method]] +** ^The xShutdown() method is called by [sqlite3_shutdown()]. +** It can be used to clean up +** any outstanding resources before process shutdown, if required. +** ^The xShutdown() method may be NULL. +** +** ^SQLite automatically serializes calls to the xInit method, +** so the xInit method need not be threadsafe. ^The +** xShutdown method is only called from [sqlite3_shutdown()] so it does +** not need to be threadsafe either. All other methods must be threadsafe +** in multithreaded applications. +** +** ^SQLite will never invoke xInit() more than once without an intervening +** call to xShutdown(). +** +** [[the xCreate() page cache methods]] +** ^SQLite invokes the xCreate() method to construct a new cache instance. +** SQLite will typically create one cache instance for each open database file, +** though this is not guaranteed. ^The +** first parameter, szPage, is the size in bytes of the pages that must +** be allocated by the cache. ^szPage will always a power of two. ^The +** second parameter szExtra is a number of bytes of extra storage +** associated with each page cache entry. ^The szExtra parameter will +** a number less than 250. SQLite will use the +** extra szExtra bytes on each page to store metadata about the underlying +** database page on disk. The value passed into szExtra depends +** on the SQLite version, the target platform, and how SQLite was compiled. +** ^The third argument to xCreate(), bPurgeable, is true if the cache being +** created will be used to cache database pages of a file stored on disk, or +** false if it is used for an in-memory database. The cache implementation +** does not have to do anything special based with the value of bPurgeable; +** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will +** never invoke xUnpin() except to deliberately delete a page. +** ^In other words, calls to xUnpin() on a cache with bPurgeable set to +** false will always have the "discard" flag set to true. +** ^Hence, a cache created with bPurgeable false will +** never contain any unpinned pages. +** +** [[the xCachesize() page cache method]] +** ^(The xCachesize() method may be called at any time by SQLite to set the +** suggested maximum cache-size (number of pages stored by) the cache +** instance passed as the first argument. This is the value configured using +** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable +** parameter, the implementation is not required to do anything with this +** value; it is advisory only. +** +** [[the xPagecount() page cache methods]] +** The xPagecount() method must return the number of pages currently +** stored in the cache, both pinned and unpinned. +** +** [[the xFetch() page cache methods]] +** The xFetch() method locates a page in the cache and returns a pointer to +** an sqlite3_pcache_page object associated with that page, or a NULL pointer. +** The pBuf element of the returned sqlite3_pcache_page object will be a +** pointer to a buffer of szPage bytes used to store the content of a +** single database page. The pExtra element of sqlite3_pcache_page will be +** a pointer to the szExtra bytes of extra storage that SQLite has requested +** for each entry in the page cache. +** +** The page to be fetched is determined by the key. ^The minimum key value +** is 1. After it has been retrieved using xFetch, the page is considered +** to be "pinned". +** +** If the requested page is already in the page cache, then the page cache +** implementation must return a pointer to the page buffer with its content +** intact. If the requested page is not already in the cache, then the +** cache implementation should use the value of the createFlag +** parameter to help it determined what action to take: +** +** <table border=1 width=85% align=center> +** <tr><th> createFlag <th> Behavior when page is not already in cache +** <tr><td> 0 <td> Do not allocate a new page. Return NULL. +** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. +** Otherwise return NULL. +** <tr><td> 2 <td> Make every effort to allocate a new page. Only return +** NULL if allocating a new page is effectively impossible. +** </table> +** +** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite +** will only use a createFlag of 2 after a prior call with a createFlag of 1 +** failed.)^ In between the xFetch() calls, SQLite may +** attempt to unpin one or more cache pages by spilling the content of +** pinned pages to disk and synching the operating system disk cache. +** +** [[the xUnpin() page cache method]] +** ^xUnpin() is called by SQLite with a pointer to a currently pinned page +** as its second argument. If the third parameter, discard, is non-zero, +** then the page must be evicted from the cache. +** ^If the discard parameter is +** zero, then the page may be discarded or retained at the discretion of +** page cache implementation. ^The page cache implementation +** may choose to evict unpinned pages at any time. +** +** The cache must not perform any reference counting. A single +** call to xUnpin() unpins the page regardless of the number of prior calls +** to xFetch(). +** +** [[the xRekey() page cache methods]] +** The xRekey() method is used to change the key value associated with the +** page passed as the second argument. If the cache +** previously contains an entry associated with newKey, it must be +** discarded. ^Any prior cache entry associated with newKey is guaranteed not +** to be pinned. +** +** When SQLite calls the xTruncate() method, the cache must discard all +** existing cache entries with page numbers (keys) greater than or equal +** to the value of the iLimit parameter passed to xTruncate(). If any +** of these pages are pinned, they are implicitly unpinned, meaning that +** they can be safely discarded. +** +** [[the xDestroy() page cache method]] +** ^The xDestroy() method is used to delete a cache allocated by xCreate(). +** All resources associated with the specified cache should be freed. ^After +** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] +** handle invalid, and will not use it with any other sqlite3_pcache_methods2 +** functions. +** +** [[the xShrink() page cache method]] +** ^SQLite invokes the xShrink() method when it wants the page cache to +** free up as much of heap memory as possible. The page cache implementation +** is not obligated to free any memory, but well-behaved implementations should +** do their best. +*/ +typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; +struct sqlite3_pcache_methods2 { + int iVersion; + void *pArg; + int (*xInit)(void*); + void (*xShutdown)(void*); + sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); + void (*xCachesize)(sqlite3_pcache*, int nCachesize); + int (*xPagecount)(sqlite3_pcache*); + sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); + void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); + void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, + unsigned oldKey, unsigned newKey); + void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); + void (*xDestroy)(sqlite3_pcache*); + void (*xShrink)(sqlite3_pcache*); +}; + +/* +** This is the obsolete pcache_methods object that has now been replaced +** by sqlite3_pcache_methods2. This object is not used by SQLite. It is +** retained in the header file for backwards compatibility only. +*/ +typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; +struct sqlite3_pcache_methods { + void *pArg; + int (*xInit)(void*); + void (*xShutdown)(void*); + sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); + void (*xCachesize)(sqlite3_pcache*, int nCachesize); + int (*xPagecount)(sqlite3_pcache*); + void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); + void (*xUnpin)(sqlite3_pcache*, void*, int discard); + void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); + void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); + void (*xDestroy)(sqlite3_pcache*); +}; + + +/* +** CAPI3REF: Online Backup Object +** +** The sqlite3_backup object records state information about an ongoing +** online backup operation. ^The sqlite3_backup object is created by +** a call to [sqlite3_backup_init()] and is destroyed by a call to +** [sqlite3_backup_finish()]. +** +** See Also: [Using the SQLite Online Backup API] +*/ +typedef struct sqlite3_backup sqlite3_backup; + +/* +** CAPI3REF: Online Backup API. +** +** The backup API copies the content of one database into another. +** It is useful either for creating backups of databases or +** for copying in-memory databases to or from persistent files. +** +** See Also: [Using the SQLite Online Backup API] +** +** ^SQLite holds a write transaction open on the destination database file +** for the duration of the backup operation. +** ^The source database is read-locked only while it is being read; +** it is not locked continuously for the entire backup operation. +** ^Thus, the backup may be performed on a live source database without +** preventing other database connections from +** reading or writing to the source database while the backup is underway. +** +** ^(To perform a backup operation: +** <ol> +** <li><b>sqlite3_backup_init()</b> is called once to initialize the +** backup, +** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer +** the data between the two databases, and finally +** <li><b>sqlite3_backup_finish()</b> is called to release all resources +** associated with the backup operation. +** </ol>)^ +** There should be exactly one call to sqlite3_backup_finish() for each +** successful call to sqlite3_backup_init(). +** +** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> +** +** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the +** [database connection] associated with the destination database +** and the database name, respectively. +** ^The database name is "main" for the main database, "temp" for the +** temporary database, or the name specified after the AS keyword in +** an [ATTACH] statement for an attached database. +** ^The S and M arguments passed to +** sqlite3_backup_init(D,N,S,M) identify the [database connection] +** and database name of the source database, respectively. +** ^The source and destination [database connections] (parameters S and D) +** must be different or else sqlite3_backup_init(D,N,S,M) will fail with +** an error. +** +** ^A call to sqlite3_backup_init() will fail, returning NULL, if +** there is already a read or read-write transaction open on the +** destination database. +** +** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is +** returned and an error code and error message are stored in the +** destination [database connection] D. +** ^The error code and message for the failed call to sqlite3_backup_init() +** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or +** [sqlite3_errmsg16()] functions. +** ^A successful call to sqlite3_backup_init() returns a pointer to an +** [sqlite3_backup] object. +** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and +** sqlite3_backup_finish() functions to perform the specified backup +** operation. +** +** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> +** +** ^Function sqlite3_backup_step(B,N) will copy up to N pages between +** the source and destination databases specified by [sqlite3_backup] object B. +** ^If N is negative, all remaining source pages are copied. +** ^If sqlite3_backup_step(B,N) successfully copies N pages and there +** are still more pages to be copied, then the function returns [SQLITE_OK]. +** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages +** from source to destination, then it returns [SQLITE_DONE]. +** ^If an error occurs while running sqlite3_backup_step(B,N), +** then an [error code] is returned. ^As well as [SQLITE_OK] and +** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], +** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an +** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. +** +** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if +** <ol> +** <li> the destination database was opened read-only, or +** <li> the destination database is using write-ahead-log journaling +** and the destination and source page sizes differ, or +** <li> the destination database is an in-memory database and the +** destination and source page sizes differ. +** </ol>)^ +** +** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then +** the [sqlite3_busy_handler | busy-handler function] +** is invoked (if one is specified). ^If the +** busy-handler returns non-zero before the lock is available, then +** [SQLITE_BUSY] is returned to the caller. ^In this case the call to +** sqlite3_backup_step() can be retried later. ^If the source +** [database connection] +** is being used to write to the source database when sqlite3_backup_step() +** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this +** case the call to sqlite3_backup_step() can be retried later on. ^(If +** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or +** [SQLITE_READONLY] is returned, then +** there is no point in retrying the call to sqlite3_backup_step(). These +** errors are considered fatal.)^ The application must accept +** that the backup operation has failed and pass the backup operation handle +** to the sqlite3_backup_finish() to release associated resources. +** +** ^The first call to sqlite3_backup_step() obtains an exclusive lock +** on the destination file. ^The exclusive lock is not released until either +** sqlite3_backup_finish() is called or the backup operation is complete +** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to +** sqlite3_backup_step() obtains a [shared lock] on the source database that +** lasts for the duration of the sqlite3_backup_step() call. +** ^Because the source database is not locked between calls to +** sqlite3_backup_step(), the source database may be modified mid-way +** through the backup process. ^If the source database is modified by an +** external process or via a database connection other than the one being +** used by the backup operation, then the backup will be automatically +** restarted by the next call to sqlite3_backup_step(). ^If the source +** database is modified by the using the same database connection as is used +** by the backup operation, then the backup database is automatically +** updated at the same time. +** +** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> +** +** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the +** application wishes to abandon the backup operation, the application +** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). +** ^The sqlite3_backup_finish() interfaces releases all +** resources associated with the [sqlite3_backup] object. +** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any +** active write-transaction on the destination database is rolled back. +** The [sqlite3_backup] object is invalid +** and may not be used following a call to sqlite3_backup_finish(). +** +** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no +** sqlite3_backup_step() errors occurred, regardless or whether or not +** sqlite3_backup_step() completed. +** ^If an out-of-memory condition or IO error occurred during any prior +** sqlite3_backup_step() call on the same [sqlite3_backup] object, then +** sqlite3_backup_finish() returns the corresponding [error code]. +** +** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() +** is not a permanent error and does not affect the return value of +** sqlite3_backup_finish(). +** +** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] +** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> +** +** ^The sqlite3_backup_remaining() routine returns the number of pages still +** to be backed up at the conclusion of the most recent sqlite3_backup_step(). +** ^The sqlite3_backup_pagecount() routine returns the total number of pages +** in the source database at the conclusion of the most recent +** sqlite3_backup_step(). +** ^(The values returned by these functions are only updated by +** sqlite3_backup_step(). If the source database is modified in a way that +** changes the size of the source database or the number of pages remaining, +** those changes are not reflected in the output of sqlite3_backup_pagecount() +** and sqlite3_backup_remaining() until after the next +** sqlite3_backup_step().)^ +** +** <b>Concurrent Usage of Database Handles</b> +** +** ^The source [database connection] may be used by the application for other +** purposes while a backup operation is underway or being initialized. +** ^If SQLite is compiled and configured to support threadsafe database +** connections, then the source database connection may be used concurrently +** from within other threads. +** +** However, the application must guarantee that the destination +** [database connection] is not passed to any other API (by any thread) after +** sqlite3_backup_init() is called and before the corresponding call to +** sqlite3_backup_finish(). SQLite does not currently check to see +** if the application incorrectly accesses the destination [database connection] +** and so no error code is reported, but the operations may malfunction +** nevertheless. Use of the destination database connection while a +** backup is in progress might also cause a mutex deadlock. +** +** If running in [shared cache mode], the application must +** guarantee that the shared cache used by the destination database +** is not accessed while the backup is running. In practice this means +** that the application must guarantee that the disk file being +** backed up to is not accessed by any connection within the process, +** not just the specific connection that was passed to sqlite3_backup_init(). +** +** The [sqlite3_backup] object itself is partially threadsafe. Multiple +** threads may safely make multiple concurrent calls to sqlite3_backup_step(). +** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() +** APIs are not strictly speaking threadsafe. If they are invoked at the +** same time as another thread is invoking sqlite3_backup_step() it is +** possible that they return invalid values. +*/ +sqlite3_backup *sqlite3_backup_init( + sqlite3 *pDest, /* Destination database handle */ + const char *zDestName, /* Destination database name */ + sqlite3 *pSource, /* Source database handle */ + const char *zSourceName /* Source database name */ +); +int sqlite3_backup_step(sqlite3_backup *p, int nPage); +int sqlite3_backup_finish(sqlite3_backup *p); +int sqlite3_backup_remaining(sqlite3_backup *p); +int sqlite3_backup_pagecount(sqlite3_backup *p); + +/* +** CAPI3REF: Unlock Notification +** METHOD: sqlite3 +** +** ^When running in shared-cache mode, a database operation may fail with +** an [SQLITE_LOCKED] error if the required locks on the shared-cache or +** individual tables within the shared-cache cannot be obtained. See +** [SQLite Shared-Cache Mode] for a description of shared-cache locking. +** ^This API may be used to register a callback that SQLite will invoke +** when the connection currently holding the required lock relinquishes it. +** ^This API is only available if the library was compiled with the +** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. +** +** See Also: [Using the SQLite Unlock Notification Feature]. +** +** ^Shared-cache locks are released when a database connection concludes +** its current transaction, either by committing it or rolling it back. +** +** ^When a connection (known as the blocked connection) fails to obtain a +** shared-cache lock and SQLITE_LOCKED is returned to the caller, the +** identity of the database connection (the blocking connection) that +** has locked the required resource is stored internally. ^After an +** application receives an SQLITE_LOCKED error, it may call the +** sqlite3_unlock_notify() method with the blocked connection handle as +** the first argument to register for a callback that will be invoked +** when the blocking connections current transaction is concluded. ^The +** callback is invoked from within the [sqlite3_step] or [sqlite3_close] +** call that concludes the blocking connection's transaction. +** +** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, +** there is a chance that the blocking connection will have already +** concluded its transaction by the time sqlite3_unlock_notify() is invoked. +** If this happens, then the specified callback is invoked immediately, +** from within the call to sqlite3_unlock_notify().)^ +** +** ^If the blocked connection is attempting to obtain a write-lock on a +** shared-cache table, and more than one other connection currently holds +** a read-lock on the same table, then SQLite arbitrarily selects one of +** the other connections to use as the blocking connection. +** +** ^(There may be at most one unlock-notify callback registered by a +** blocked connection. If sqlite3_unlock_notify() is called when the +** blocked connection already has a registered unlock-notify callback, +** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is +** called with a NULL pointer as its second argument, then any existing +** unlock-notify callback is canceled. ^The blocked connections +** unlock-notify callback may also be canceled by closing the blocked +** connection using [sqlite3_close()]. +** +** The unlock-notify callback is not reentrant. If an application invokes +** any sqlite3_xxx API functions from within an unlock-notify callback, a +** crash or deadlock may be the result. +** +** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always +** returns SQLITE_OK. +** +** <b>Callback Invocation Details</b> +** +** When an unlock-notify callback is registered, the application provides a +** single void* pointer that is passed to the callback when it is invoked. +** However, the signature of the callback function allows SQLite to pass +** it an array of void* context pointers. The first argument passed to +** an unlock-notify callback is a pointer to an array of void* pointers, +** and the second is the number of entries in the array. +** +** When a blocking connection's transaction is concluded, there may be +** more than one blocked connection that has registered for an unlock-notify +** callback. ^If two or more such blocked connections have specified the +** same callback function, then instead of invoking the callback function +** multiple times, it is invoked once with the set of void* context pointers +** specified by the blocked connections bundled together into an array. +** This gives the application an opportunity to prioritize any actions +** related to the set of unblocked database connections. +** +** <b>Deadlock Detection</b> +** +** Assuming that after registering for an unlock-notify callback a +** database waits for the callback to be issued before taking any further +** action (a reasonable assumption), then using this API may cause the +** application to deadlock. For example, if connection X is waiting for +** connection Y's transaction to be concluded, and similarly connection +** Y is waiting on connection X's transaction, then neither connection +** will proceed and the system may remain deadlocked indefinitely. +** +** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock +** detection. ^If a given call to sqlite3_unlock_notify() would put the +** system in a deadlocked state, then SQLITE_LOCKED is returned and no +** unlock-notify callback is registered. The system is said to be in +** a deadlocked state if connection A has registered for an unlock-notify +** callback on the conclusion of connection B's transaction, and connection +** B has itself registered for an unlock-notify callback when connection +** A's transaction is concluded. ^Indirect deadlock is also detected, so +** the system is also considered to be deadlocked if connection B has +** registered for an unlock-notify callback on the conclusion of connection +** C's transaction, where connection C is waiting on connection A. ^Any +** number of levels of indirection are allowed. +** +** <b>The "DROP TABLE" Exception</b> +** +** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost +** always appropriate to call sqlite3_unlock_notify(). There is however, +** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, +** SQLite checks if there are any currently executing SELECT statements +** that belong to the same connection. If there are, SQLITE_LOCKED is +** returned. In this case there is no "blocking connection", so invoking +** sqlite3_unlock_notify() results in the unlock-notify callback being +** invoked immediately. If the application then re-attempts the "DROP TABLE" +** or "DROP INDEX" query, an infinite loop might be the result. +** +** One way around this problem is to check the extended error code returned +** by an sqlite3_step() call. ^(If there is a blocking connection, then the +** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in +** the special "DROP TABLE/INDEX" case, the extended error code is just +** SQLITE_LOCKED.)^ +*/ +int sqlite3_unlock_notify( + sqlite3 *pBlocked, /* Waiting connection */ + void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ + void *pNotifyArg /* Argument to pass to xNotify */ +); + + +/* +** CAPI3REF: String Comparison +** +** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications +** and extensions to compare the contents of two buffers containing UTF-8 +** strings in a case-independent fashion, using the same definition of "case +** independence" that SQLite uses internally when comparing identifiers. +*/ +int sqlite3_stricmp(const char *, const char *); +int sqlite3_strnicmp(const char *, const char *, int); + +/* +** CAPI3REF: String Globbing +* +** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if +** string X matches the [GLOB] pattern P. +** ^The definition of [GLOB] pattern matching used in +** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the +** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function +** is case sensitive. +** +** Note that this routine returns zero on a match and non-zero if the strings +** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. +** +** See also: [sqlite3_strlike()]. +*/ +int sqlite3_strglob(const char *zGlob, const char *zStr); + +/* +** CAPI3REF: String LIKE Matching +* +** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if +** string X matches the [LIKE] pattern P with escape character E. +** ^The definition of [LIKE] pattern matching used in +** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" +** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without +** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. +** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case +** insensitive - equivalent upper and lower case ASCII characters match +** one another. +** +** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though +** only ASCII characters are case folded. +** +** Note that this routine returns zero on a match and non-zero if the strings +** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. +** +** See also: [sqlite3_strglob()]. +*/ +int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); + +/* +** CAPI3REF: Error Logging Interface +** +** ^The [sqlite3_log()] interface writes a message into the [error log] +** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. +** ^If logging is enabled, the zFormat string and subsequent arguments are +** used with [sqlite3_snprintf()] to generate the final output string. +** +** The sqlite3_log() interface is intended for use by extensions such as +** virtual tables, collating functions, and SQL functions. While there is +** nothing to prevent an application from calling sqlite3_log(), doing so +** is considered bad form. +** +** The zFormat string must not be NULL. +** +** To avoid deadlocks and other threading problems, the sqlite3_log() routine +** will not use dynamically allocated memory. The log message is stored in +** a fixed-length buffer on the stack. If the log message is longer than +** a few hundred characters, it will be truncated to the length of the +** buffer. +*/ +void sqlite3_log(int iErrCode, const char *zFormat, ...); + +/* +** CAPI3REF: Write-Ahead Log Commit Hook +** METHOD: sqlite3 +** +** ^The [sqlite3_wal_hook()] function is used to register a callback that +** is invoked each time data is committed to a database in wal mode. +** +** ^(The callback is invoked by SQLite after the commit has taken place and +** the associated write-lock on the database released)^, so the implementation +** may read, write or [checkpoint] the database as required. +** +** ^The first parameter passed to the callback function when it is invoked +** is a copy of the third parameter passed to sqlite3_wal_hook() when +** registering the callback. ^The second is a copy of the database handle. +** ^The third parameter is the name of the database that was written to - +** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter +** is the number of pages currently in the write-ahead log file, +** including those that were just committed. +** +** The callback function should normally return [SQLITE_OK]. ^If an error +** code is returned, that error will propagate back up through the +** SQLite code base to cause the statement that provoked the callback +** to report an error, though the commit will have still occurred. If the +** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value +** that does not correspond to any valid SQLite error code, the results +** are undefined. +** +** A single database handle may have at most a single write-ahead log callback +** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any +** previously registered write-ahead log callback. ^The return value is +** a copy of the third parameter from the previous call, if any, or 0. +** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the +** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will +** overwrite any prior [sqlite3_wal_hook()] settings. +*/ +void *sqlite3_wal_hook( + sqlite3*, + int(*)(void *,sqlite3*,const char*,int), + void* +); + +/* +** CAPI3REF: Configure an auto-checkpoint +** METHOD: sqlite3 +** +** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around +** [sqlite3_wal_hook()] that causes any database on [database connection] D +** to automatically [checkpoint] +** after committing a transaction if there are N or +** more frames in the [write-ahead log] file. ^Passing zero or +** a negative value as the nFrame parameter disables automatic +** checkpoints entirely. +** +** ^The callback registered by this function replaces any existing callback +** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback +** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism +** configured by this function. +** +** ^The [wal_autocheckpoint pragma] can be used to invoke this interface +** from SQL. +** +** ^Checkpoints initiated by this mechanism are +** [sqlite3_wal_checkpoint_v2|PASSIVE]. +** +** ^Every new [database connection] defaults to having the auto-checkpoint +** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] +** pages. The use of this interface +** is only necessary if the default setting is found to be suboptimal +** for a particular application. +*/ +int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); + +/* +** CAPI3REF: Checkpoint a database +** METHOD: sqlite3 +** +** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to +** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ +** +** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the +** [write-ahead log] for database X on [database connection] D to be +** transferred into the database file and for the write-ahead log to +** be reset. See the [checkpointing] documentation for addition +** information. +** +** This interface used to be the only way to cause a checkpoint to +** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] +** interface was added. This interface is retained for backwards +** compatibility and as a convenience for applications that need to manually +** start a callback but which do not need the full power (and corresponding +** complication) of [sqlite3_wal_checkpoint_v2()]. +*/ +int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); + +/* +** CAPI3REF: Checkpoint a database +** METHOD: sqlite3 +** +** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint +** operation on database X of [database connection] D in mode M. Status +** information is written back into integers pointed to by L and C.)^ +** ^(The M parameter must be a valid [checkpoint mode]:)^ +** +** <dl> +** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> +** ^Checkpoint as many frames as possible without waiting for any database +** readers or writers to finish, then sync the database file if all frames +** in the log were checkpointed. ^The [busy-handler callback] +** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. +** ^On the other hand, passive mode might leave the checkpoint unfinished +** if there are concurrent readers or writers. +** +** <dt>SQLITE_CHECKPOINT_FULL<dd> +** ^This mode blocks (it invokes the +** [sqlite3_busy_handler|busy-handler callback]) until there is no +** database writer and all readers are reading from the most recent database +** snapshot. ^It then checkpoints all frames in the log file and syncs the +** database file. ^This mode blocks new database writers while it is pending, +** but new database readers are allowed to continue unimpeded. +** +** <dt>SQLITE_CHECKPOINT_RESTART<dd> +** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition +** that after checkpointing the log file it blocks (calls the +** [busy-handler callback]) +** until all readers are reading from the database file only. ^This ensures +** that the next writer will restart the log file from the beginning. +** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new +** database writer attempts while it is pending, but does not impede readers. +** +** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> +** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the +** addition that it also truncates the log file to zero bytes just prior +** to a successful return. +** </dl> +** +** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in +** the log file or to -1 if the checkpoint could not run because +** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not +** NULL,then *pnCkpt is set to the total number of checkpointed frames in the +** log file (including any that were already checkpointed before the function +** was called) or to -1 if the checkpoint could not run due to an error or +** because the database is not in WAL mode. ^Note that upon successful +** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been +** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. +** +** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If +** any other process is running a checkpoint operation at the same time, the +** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a +** busy-handler configured, it will not be invoked in this case. +** +** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the +** exclusive "writer" lock on the database file. ^If the writer lock cannot be +** obtained immediately, and a busy-handler is configured, it is invoked and +** the writer lock retried until either the busy-handler returns 0 or the lock +** is successfully obtained. ^The busy-handler is also invoked while waiting for +** database readers as described above. ^If the busy-handler returns 0 before +** the writer lock is obtained or while waiting for database readers, the +** checkpoint operation proceeds from that point in the same way as +** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible +** without blocking any further. ^SQLITE_BUSY is returned in this case. +** +** ^If parameter zDb is NULL or points to a zero length string, then the +** specified operation is attempted on all WAL databases [attached] to +** [database connection] db. In this case the +** values written to output parameters *pnLog and *pnCkpt are undefined. ^If +** an SQLITE_BUSY error is encountered when processing one or more of the +** attached WAL databases, the operation is still attempted on any remaining +** attached databases and SQLITE_BUSY is returned at the end. ^If any other +** error occurs while processing an attached database, processing is abandoned +** and the error code is returned to the caller immediately. ^If no error +** (SQLITE_BUSY or otherwise) is encountered while processing the attached +** databases, SQLITE_OK is returned. +** +** ^If database zDb is the name of an attached database that is not in WAL +** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If +** zDb is not NULL (or a zero length string) and is not the name of any +** attached database, SQLITE_ERROR is returned to the caller. +** +** ^Unless it returns SQLITE_MISUSE, +** the sqlite3_wal_checkpoint_v2() interface +** sets the error information that is queried by +** [sqlite3_errcode()] and [sqlite3_errmsg()]. +** +** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface +** from SQL. +*/ +int sqlite3_wal_checkpoint_v2( + sqlite3 *db, /* Database handle */ + const char *zDb, /* Name of attached database (or NULL) */ + int eMode, /* SQLITE_CHECKPOINT_* value */ + int *pnLog, /* OUT: Size of WAL log in frames */ + int *pnCkpt /* OUT: Total number of frames checkpointed */ +); + +/* +** CAPI3REF: Checkpoint Mode Values +** KEYWORDS: {checkpoint mode} +** +** These constants define all valid values for the "checkpoint mode" passed +** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. +** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the +** meaning of each of these checkpoint modes. +*/ +#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ +#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ +#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ +#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ + +/* +** CAPI3REF: Virtual Table Interface Configuration +** +** This function may be called by either the [xConnect] or [xCreate] method +** of a [virtual table] implementation to configure +** various facets of the virtual table interface. +** +** If this interface is invoked outside the context of an xConnect or +** xCreate virtual table method then the behavior is undefined. +** +** In the call sqlite3_vtab_config(D,C,...) the D parameter is the +** [database connection] in which the virtual table is being created and +** which is passed in as the first argument to the [xConnect] or [xCreate] +** method that is invoking sqlite3_vtab_config(). The C parameter is one +** of the [virtual table configuration options]. The presence and meaning +** of parameters after C depend on which [virtual table configuration option] +** is used. +*/ +int sqlite3_vtab_config(sqlite3*, int op, ...); + +/* +** CAPI3REF: Virtual Table Configuration Options +** KEYWORDS: {virtual table configuration options} +** KEYWORDS: {virtual table configuration option} +** +** These macros define the various options to the +** [sqlite3_vtab_config()] interface that [virtual table] implementations +** can use to customize and optimize their behavior. +** +** <dl> +** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] +** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> +** <dd>Calls of the form +** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, +** where X is an integer. If X is zero, then the [virtual table] whose +** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not +** support constraints. In this configuration (which is the default) if +** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire +** statement is rolled back as if [ON CONFLICT | OR ABORT] had been +** specified as part of the users SQL statement, regardless of the actual +** ON CONFLICT mode specified. +** +** If X is non-zero, then the virtual table implementation guarantees +** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before +** any modifications to internal or persistent data structures have been made. +** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite +** is able to roll back a statement or database transaction, and abandon +** or continue processing the current SQL statement as appropriate. +** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns +** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode +** had been ABORT. +** +** Virtual table implementations that are required to handle OR REPLACE +** must do so within the [xUpdate] method. If a call to the +** [sqlite3_vtab_on_conflict()] function indicates that the current ON +** CONFLICT policy is REPLACE, the virtual table implementation should +** silently replace the appropriate rows within the xUpdate callback and +** return SQLITE_OK. Or, if this is not possible, it may return +** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT +** constraint handling. +** </dd> +** +** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> +** <dd>Calls of the form +** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the +** the [xConnect] or [xCreate] methods of a [virtual table] implmentation +** prohibits that virtual table from being used from within triggers and +** views. +** </dd> +** +** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> +** <dd>Calls of the form +** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the +** the [xConnect] or [xCreate] methods of a [virtual table] implmentation +** identify that virtual table as being safe to use from within triggers +** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the +** virtual table can do no serious harm even if it is controlled by a +** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS +** flag unless absolutely necessary. +** </dd> +** </dl> +*/ +#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 +#define SQLITE_VTAB_INNOCUOUS 2 +#define SQLITE_VTAB_DIRECTONLY 3 + +/* +** CAPI3REF: Determine The Virtual Table Conflict Policy +** +** This function may only be called from within a call to the [xUpdate] method +** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The +** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], +** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode +** of the SQL statement that triggered the call to the [xUpdate] method of the +** [virtual table]. +*/ +int sqlite3_vtab_on_conflict(sqlite3 *); + +/* +** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE +** +** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] +** method of a [virtual table], then it might return true if the +** column is being fetched as part of an UPDATE operation during which the +** column value will not change. The virtual table implementation can use +** this hint as permission to substitute a return value that is less +** expensive to compute and that the corresponding +** [xUpdate] method understands as a "no-change" value. +** +** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that +** the column is not changed by the UPDATE statement, then the xColumn +** method can optionally return without setting a result, without calling +** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. +** In that case, [sqlite3_value_nochange(X)] will return true for the +** same column in the [xUpdate] method. +** +** The sqlite3_vtab_nochange() routine is an optimization. Virtual table +** implementations should continue to give a correct answer even if the +** sqlite3_vtab_nochange() interface were to always return false. In the +** current implementation, the sqlite3_vtab_nochange() interface does always +** returns false for the enhanced [UPDATE FROM] statement. +*/ +int sqlite3_vtab_nochange(sqlite3_context*); + +/* +** CAPI3REF: Determine The Collation For a Virtual Table Constraint +** METHOD: sqlite3_index_info +** +** This function may only be called from within a call to the [xBestIndex] +** method of a [virtual table]. This function returns a pointer to a string +** that is the name of the appropriate collation sequence to use for text +** comparisons on the constraint identified by its arguments. +** +** The first argument must be the pointer to the [sqlite3_index_info] object +** that is the first parameter to the xBestIndex() method. The second argument +** must be an index into the aConstraint[] array belonging to the +** sqlite3_index_info structure passed to xBestIndex. +** +** Important: +** The first parameter must be the same pointer that is passed into the +** xBestMethod() method. The first parameter may not be a pointer to a +** different [sqlite3_index_info] object, even an exact copy. +** +** The return value is computed as follows: +** +** <ol> +** <li><p> If the constraint comes from a WHERE clause expression that contains +** a [COLLATE operator], then the name of the collation specified by +** that COLLATE operator is returned. +** <li><p> If there is no COLLATE operator, but the column that is the subject +** of the constraint specifies an alternative collating sequence via +** a [COLLATE clause] on the column definition within the CREATE TABLE +** statement that was passed into [sqlite3_declare_vtab()], then the +** name of that alternative collating sequence is returned. +** <li><p> Otherwise, "BINARY" is returned. +** </ol> +*/ +SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); + +/* +** CAPI3REF: Determine if a virtual table query is DISTINCT +** METHOD: sqlite3_index_info +** +** This API may only be used from within an [xBestIndex|xBestIndex method] +** of a [virtual table] implementation. The result of calling this +** interface from outside of xBestIndex() is undefined and probably harmful. +** +** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and +** 3. The integer returned by sqlite3_vtab_distinct() +** gives the virtual table additional information about how the query +** planner wants the output to be ordered. As long as the virtual table +** can meet the ordering requirements of the query planner, it may set +** the "orderByConsumed" flag. +** +** <ol><li value="0"><p> +** ^If the sqlite3_vtab_distinct() interface returns 0, that means +** that the query planner needs the virtual table to return all rows in the +** sort order defined by the "nOrderBy" and "aOrderBy" fields of the +** [sqlite3_index_info] object. This is the default expectation. If the +** virtual table outputs all rows in sorted order, then it is always safe for +** the xBestIndex method to set the "orderByConsumed" flag, regardless of +** the return value from sqlite3_vtab_distinct(). +** <li value="1"><p> +** ^(If the sqlite3_vtab_distinct() interface returns 1, that means +** that the query planner does not need the rows to be returned in sorted order +** as long as all rows with the same values in all columns identified by the +** "aOrderBy" field are adjacent.)^ This mode is used when the query planner +** is doing a GROUP BY. +** <li value="2"><p> +** ^(If the sqlite3_vtab_distinct() interface returns 2, that means +** that the query planner does not need the rows returned in any particular +** order, as long as rows with the same values in all "aOrderBy" columns +** are adjacent.)^ ^(Furthermore, only a single row for each particular +** combination of values in the columns identified by the "aOrderBy" field +** needs to be returned.)^ ^It is always ok for two or more rows with the same +** values in all "aOrderBy" columns to be returned, as long as all such rows +** are adjacent. ^The virtual table may, if it chooses, omit extra rows +** that have the same value for all columns identified by "aOrderBy". +** ^However omitting the extra rows is optional. +** This mode is used for a DISTINCT query. +** <li value="3"><p> +** ^(If the sqlite3_vtab_distinct() interface returns 3, that means +** that the query planner needs only distinct rows but it does need the +** rows to be sorted.)^ ^The virtual table implementation is free to omit +** rows that are identical in all aOrderBy columns, if it wants to, but +** it is not required to omit any rows. This mode is used for queries +** that have both DISTINCT and ORDER BY clauses. +** </ol> +** +** ^For the purposes of comparing virtual table output values to see if the +** values are same value for sorting purposes, two NULL values are considered +** to be the same. In other words, the comparison operator is "IS" +** (or "IS NOT DISTINCT FROM") and not "==". +** +** If a virtual table implementation is unable to meet the requirements +** specified above, then it must not set the "orderByConsumed" flag in the +** [sqlite3_index_info] object or an incorrect answer may result. +** +** ^A virtual table implementation is always free to return rows in any order +** it wants, as long as the "orderByConsumed" flag is not set. ^When the +** the "orderByConsumed" flag is unset, the query planner will add extra +** [bytecode] to ensure that the final results returned by the SQL query are +** ordered correctly. The use of the "orderByConsumed" flag and the +** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful +** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" +** flag might help queries against a virtual table to run faster. Being +** overly aggressive and setting the "orderByConsumed" flag when it is not +** valid to do so, on the other hand, might cause SQLite to return incorrect +** results. +*/ +int sqlite3_vtab_distinct(sqlite3_index_info*); + +/* +** CAPI3REF: Identify and handle IN constraints in xBestIndex +** +** This interface may only be used from within an +** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. +** The result of invoking this interface from any other context is +** undefined and probably harmful. +** +** ^(A constraint on a virtual table of the form +** "[IN operator|column IN (...)]" is +** communicated to the xBestIndex method as a +** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use +** this constraint, it must set the corresponding +** aConstraintUsage[].argvIndex to a postive integer. ^(Then, under +** the usual mode of handling IN operators, SQLite generates [bytecode] +** that invokes the [xFilter|xFilter() method] once for each value +** on the right-hand side of the IN operator.)^ Thus the virtual table +** only sees a single value from the right-hand side of the IN operator +** at a time. +** +** In some cases, however, it would be advantageous for the virtual +** table to see all values on the right-hand of the IN operator all at +** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: +** +** <ol> +** <li><p> +** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) +** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint +** is an [IN operator] that can be processed all at once. ^In other words, +** sqlite3_vtab_in() with -1 in the third argument is a mechanism +** by which the virtual table can ask SQLite if all-at-once processing +** of the IN operator is even possible. +** +** <li><p> +** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates +** to SQLite that the virtual table does or does not want to process +** the IN operator all-at-once, respectively. ^Thus when the third +** parameter (F) is non-negative, this interface is the mechanism by +** which the virtual table tells SQLite how it wants to process the +** IN operator. +** </ol> +** +** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times +** within the same xBestIndex method call. ^For any given P,N pair, +** the return value from sqlite3_vtab_in(P,N,F) will always be the same +** within the same xBestIndex call. ^If the interface returns true +** (non-zero), that means that the constraint is an IN operator +** that can be processed all-at-once. ^If the constraint is not an IN +** operator or cannot be processed all-at-once, then the interface returns +** false. +** +** ^(All-at-once processing of the IN operator is selected if both of the +** following conditions are met: +** +** <ol> +** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive +** integer. This is how the virtual table tells SQLite that it wants to +** use the N-th constraint. +** +** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was +** non-negative had F>=1. +** </ol>)^ +** +** ^If either or both of the conditions above are false, then SQLite uses +** the traditional one-at-a-time processing strategy for the IN constraint. +** ^If both conditions are true, then the argvIndex-th parameter to the +** xFilter method will be an [sqlite3_value] that appears to be NULL, +** but which can be passed to [sqlite3_vtab_in_first()] and +** [sqlite3_vtab_in_next()] to find all values on the right-hand side +** of the IN constraint. +*/ +int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); + +/* +** CAPI3REF: Find all elements on the right-hand side of an IN constraint. +** +** These interfaces are only useful from within the +** [xFilter|xFilter() method] of a [virtual table] implementation. +** The result of invoking these interfaces from any other context +** is undefined and probably harmful. +** +** The X parameter in a call to sqlite3_vtab_in_first(X,P) or +** sqlite3_vtab_in_next(X,P) must be one of the parameters to the +** xFilter method which invokes these routines, and specifically +** a parameter that was previously selected for all-at-once IN constraint +** processing use the [sqlite3_vtab_in()] interface in the +** [xBestIndex|xBestIndex method]. ^(If the X parameter is not +** an xFilter argument that was selected for all-at-once IN constraint +** processing, then these routines return [SQLITE_MISUSE])^ or perhaps +** exhibit some other undefined or harmful behavior. +** +** ^(Use these routines to access all values on the right-hand side +** of the IN constraint using code like the following: +** +** <blockquote><pre> +** for(rc=sqlite3_vtab_in_first(pList, &pVal); +** rc==SQLITE_OK && pVal +** rc=sqlite3_vtab_in_next(pList, &pVal) +** ){ +** // do something with pVal +** } +** if( rc!=SQLITE_OK ){ +** // an error has occurred +** } +** </pre></blockquote>)^ +** +** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) +** routines return SQLITE_OK and set *P to point to the first or next value +** on the RHS of the IN constraint. ^If there are no more values on the +** right hand side of the IN constraint, then *P is set to NULL and these +** routines return [SQLITE_DONE]. ^The return value might be +** some other value, such as SQLITE_NOMEM, in the event of a malfunction. +** +** The *ppOut values returned by these routines are only valid until the +** next call to either of these routines or until the end of the xFilter +** method from which these routines were called. If the virtual table +** implementation needs to retain the *ppOut values for longer, it must make +** copies. The *ppOut values are [protected sqlite3_value|protected]. +*/ +int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); +int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); + +/* +** CAPI3REF: Constraint values in xBestIndex() +** METHOD: sqlite3_index_info +** +** This API may only be used from within the [xBestIndex|xBestIndex method] +** of a [virtual table] implementation. The result of calling this interface +** from outside of an xBestIndex method are undefined and probably harmful. +** +** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within +** the [xBestIndex] method of a [virtual table] implementation, with P being +** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and +** J being a 0-based index into P->aConstraint[], then this routine +** attempts to set *V to the value of the right-hand operand of +** that constraint if the right-hand operand is known. ^If the +** right-hand operand is not known, then *V is set to a NULL pointer. +** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if +** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) +** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th +** constraint is not available. ^The sqlite3_vtab_rhs_value() interface +** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if +** something goes wrong. +** +** The sqlite3_vtab_rhs_value() interface is usually only successful if +** the right-hand operand of a constraint is a literal value in the original +** SQL statement. If the right-hand operand is an expression or a reference +** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() +** will probably return [SQLITE_NOTFOUND]. +** +** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and +** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such +** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ +** +** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value +** and remains valid for the duration of the xBestIndex method call. +** ^When xBestIndex returns, the sqlite3_value object returned by +** sqlite3_vtab_rhs_value() is automatically deallocated. +** +** The "_rhs_" in the name of this routine is an abbreviation for +** "Right-Hand Side". +*/ +int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); + +/* +** CAPI3REF: Conflict resolution modes +** KEYWORDS: {conflict resolution mode} +** +** These constants are returned by [sqlite3_vtab_on_conflict()] to +** inform a [virtual table] implementation what the [ON CONFLICT] mode +** is for the SQL statement being evaluated. +** +** Note that the [SQLITE_IGNORE] constant is also used as a potential +** return value from the [sqlite3_set_authorizer()] callback and that +** [SQLITE_ABORT] is also a [result code]. +*/ +#define SQLITE_ROLLBACK 1 +/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ +#define SQLITE_FAIL 3 +/* #define SQLITE_ABORT 4 // Also an error code */ +#define SQLITE_REPLACE 5 + +/* +** CAPI3REF: Prepared Statement Scan Status Opcodes +** KEYWORDS: {scanstatus options} +** +** The following constants can be used for the T parameter to the +** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a +** different metric for sqlite3_stmt_scanstatus() to return. +** +** When the value returned to V is a string, space to hold that string is +** managed by the prepared statement S and will be automatically freed when +** S is finalized. +** +** <dl> +** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> +** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be +** set to the total number of times that the X-th loop has run.</dd> +** +** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> +** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set +** to the total number of rows examined by all iterations of the X-th loop.</dd> +** +** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> +** <dd>^The "double" variable pointed to by the V parameter will be set to the +** query planner's estimate for the average number of rows output from each +** iteration of the X-th loop. If the query planner's estimates was accurate, +** then this value will approximate the quotient NVISIT/NLOOP and the +** product of this value for all prior loops with the same SELECTID will +** be the NLOOP value for the current loop. +** +** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> +** <dd>^The "const char *" variable pointed to by the V parameter will be set +** to a zero-terminated UTF-8 string containing the name of the index or table +** used for the X-th loop. +** +** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> +** <dd>^The "const char *" variable pointed to by the V parameter will be set +** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] +** description for the X-th loop. +** +** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> +** <dd>^The "int" variable pointed to by the V parameter will be set to the +** "select-id" for the X-th loop. The select-id identifies which query or +** subquery the loop is part of. The main query has a select-id of zero. +** The select-id is the same value as is output in the first column +** of an [EXPLAIN QUERY PLAN] query. +** </dl> +*/ +#define SQLITE_SCANSTAT_NLOOP 0 +#define SQLITE_SCANSTAT_NVISIT 1 +#define SQLITE_SCANSTAT_EST 2 +#define SQLITE_SCANSTAT_NAME 3 +#define SQLITE_SCANSTAT_EXPLAIN 4 +#define SQLITE_SCANSTAT_SELECTID 5 + +/* +** CAPI3REF: Prepared Statement Scan Status +** METHOD: sqlite3_stmt +** +** This interface returns information about the predicted and measured +** performance for pStmt. Advanced applications can use this +** interface to compare the predicted and the measured performance and +** issue warnings and/or rerun [ANALYZE] if discrepancies are found. +** +** Since this interface is expected to be rarely used, it is only +** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] +** compile-time option. +** +** The "iScanStatusOp" parameter determines which status information to return. +** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior +** of this interface is undefined. +** ^The requested measurement is written into a variable pointed to by +** the "pOut" parameter. +** Parameter "idx" identifies the specific loop to retrieve statistics for. +** Loops are numbered starting from zero. ^If idx is out of range - less than +** zero or greater than or equal to the total number of loops used to implement +** the statement - a non-zero value is returned and the variable that pOut +** points to is unchanged. +** +** ^Statistics might not be available for all loops in all statements. ^In cases +** where there exist loops with no available statistics, this function behaves +** as if the loop did not exist - it returns non-zero and leave the variable +** that pOut points to unchanged. +** +** See also: [sqlite3_stmt_scanstatus_reset()] +*/ +int sqlite3_stmt_scanstatus( + sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ + int idx, /* Index of loop to report on */ + int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ + void *pOut /* Result written here */ +); + +/* +** CAPI3REF: Zero Scan-Status Counters +** METHOD: sqlite3_stmt +** +** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. +** +** This API is only available if the library is built with pre-processor +** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. +*/ +void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); + +/* +** CAPI3REF: Flush caches to disk mid-transaction +** METHOD: sqlite3 +** +** ^If a write-transaction is open on [database connection] D when the +** [sqlite3_db_cacheflush(D)] interface invoked, any dirty +** pages in the pager-cache that are not currently in use are written out +** to disk. A dirty page may be in use if a database cursor created by an +** active SQL statement is reading from it, or if it is page 1 of a database +** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] +** interface flushes caches for all schemas - "main", "temp", and +** any [attached] databases. +** +** ^If this function needs to obtain extra database locks before dirty pages +** can be flushed to disk, it does so. ^If those locks cannot be obtained +** immediately and there is a busy-handler callback configured, it is invoked +** in the usual manner. ^If the required lock still cannot be obtained, then +** the database is skipped and an attempt made to flush any dirty pages +** belonging to the next (if any) database. ^If any databases are skipped +** because locks cannot be obtained, but no other error occurs, this +** function returns SQLITE_BUSY. +** +** ^If any other error occurs while flushing dirty pages to disk (for +** example an IO error or out-of-memory condition), then processing is +** abandoned and an SQLite [error code] is returned to the caller immediately. +** +** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. +** +** ^This function does not set the database handle error code or message +** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. +*/ +int sqlite3_db_cacheflush(sqlite3*); + +/* +** CAPI3REF: The pre-update hook. +** METHOD: sqlite3 +** +** ^These interfaces are only available if SQLite is compiled using the +** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. +** +** ^The [sqlite3_preupdate_hook()] interface registers a callback function +** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation +** on a database table. +** ^At most one preupdate hook may be registered at a time on a single +** [database connection]; each call to [sqlite3_preupdate_hook()] overrides +** the previous setting. +** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] +** with a NULL pointer as the second parameter. +** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as +** the first parameter to callbacks. +** +** ^The preupdate hook only fires for changes to real database tables; the +** preupdate hook is not invoked for changes to [virtual tables] or to +** system tables like sqlite_sequence or sqlite_stat1. +** +** ^The second parameter to the preupdate callback is a pointer to +** the [database connection] that registered the preupdate hook. +** ^The third parameter to the preupdate callback is one of the constants +** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the +** kind of update operation that is about to occur. +** ^(The fourth parameter to the preupdate callback is the name of the +** database within the database connection that is being modified. This +** will be "main" for the main database or "temp" for TEMP tables or +** the name given after the AS keyword in the [ATTACH] statement for attached +** databases.)^ +** ^The fifth parameter to the preupdate callback is the name of the +** table that is being modified. +** +** For an UPDATE or DELETE operation on a [rowid table], the sixth +** parameter passed to the preupdate callback is the initial [rowid] of the +** row being modified or deleted. For an INSERT operation on a rowid table, +** or any operation on a WITHOUT ROWID table, the value of the sixth +** parameter is undefined. For an INSERT or UPDATE on a rowid table the +** seventh parameter is the final rowid value of the row being inserted +** or updated. The value of the seventh parameter passed to the callback +** function is not defined for operations on WITHOUT ROWID tables, or for +** DELETE operations on rowid tables. +** +** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], +** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces +** provide additional information about a preupdate event. These routines +** may only be called from within a preupdate callback. Invoking any of +** these routines from outside of a preupdate callback or with a +** [database connection] pointer that is different from the one supplied +** to the preupdate callback results in undefined and probably undesirable +** behavior. +** +** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns +** in the row that is being inserted, updated, or deleted. +** +** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to +** a [protected sqlite3_value] that contains the value of the Nth column of +** the table row before it is updated. The N parameter must be between 0 +** and one less than the number of columns or the behavior will be +** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE +** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the +** behavior is undefined. The [sqlite3_value] that P points to +** will be destroyed when the preupdate callback returns. +** +** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to +** a [protected sqlite3_value] that contains the value of the Nth column of +** the table row after it is updated. The N parameter must be between 0 +** and one less than the number of columns or the behavior will be +** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE +** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the +** behavior is undefined. The [sqlite3_value] that P points to +** will be destroyed when the preupdate callback returns. +** +** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate +** callback was invoked as a result of a direct insert, update, or delete +** operation; or 1 for inserts, updates, or deletes invoked by top-level +** triggers; or 2 for changes resulting from triggers called by top-level +** triggers; and so forth. +** +** When the [sqlite3_blob_write()] API is used to update a blob column, +** the pre-update hook is invoked with SQLITE_DELETE. This is because the +** in this case the new values are not available. In this case, when a +** callback made with op==SQLITE_DELETE is actuall a write using the +** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns +** the index of the column being written. In other cases, where the +** pre-update hook is being invoked for some other reason, including a +** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. +** +** See also: [sqlite3_update_hook()] +*/ +#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) +void *sqlite3_preupdate_hook( + sqlite3 *db, + void(*xPreUpdate)( + void *pCtx, /* Copy of third arg to preupdate_hook() */ + sqlite3 *db, /* Database handle */ + int op, /* SQLITE_UPDATE, DELETE or INSERT */ + char const *zDb, /* Database name */ + char const *zName, /* Table name */ + sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ + sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ + ), + void* +); +int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); +int sqlite3_preupdate_count(sqlite3 *); +int sqlite3_preupdate_depth(sqlite3 *); +int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); +int sqlite3_preupdate_blobwrite(sqlite3 *); +#endif + +/* +** CAPI3REF: Low-level system error code +** METHOD: sqlite3 +** +** ^Attempt to return the underlying operating system error code or error +** number that caused the most recent I/O error or failure to open a file. +** The return value is OS-dependent. For example, on unix systems, after +** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be +** called to get back the underlying "errno" that caused the problem, such +** as ENOSPC, EAUTH, EISDIR, and so forth. +*/ +int sqlite3_system_errno(sqlite3*); + +/* +** CAPI3REF: Database Snapshot +** KEYWORDS: {snapshot} {sqlite3_snapshot} +** +** An instance of the snapshot object records the state of a [WAL mode] +** database for some specific point in history. +** +** In [WAL mode], multiple [database connections] that are open on the +** same database file can each be reading a different historical version +** of the database file. When a [database connection] begins a read +** transaction, that connection sees an unchanging copy of the database +** as it existed for the point in time when the transaction first started. +** Subsequent changes to the database from other connections are not seen +** by the reader until a new read transaction is started. +** +** The sqlite3_snapshot object records state information about an historical +** version of the database file so that it is possible to later open a new read +** transaction that sees that historical version of the database rather than +** the most recent version. +*/ +typedef struct sqlite3_snapshot { + unsigned char hidden[48]; +} sqlite3_snapshot; + +/* +** CAPI3REF: Record A Database Snapshot +** CONSTRUCTOR: sqlite3_snapshot +** +** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a +** new [sqlite3_snapshot] object that records the current state of +** schema S in database connection D. ^On success, the +** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly +** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. +** If there is not already a read-transaction open on schema S when +** this function is called, one is opened automatically. +** +** The following must be true for this function to succeed. If any of +** the following statements are false when sqlite3_snapshot_get() is +** called, SQLITE_ERROR is returned. The final value of *P is undefined +** in this case. +** +** <ul> +** <li> The database handle must not be in [autocommit mode]. +** +** <li> Schema S of [database connection] D must be a [WAL mode] database. +** +** <li> There must not be a write transaction open on schema S of database +** connection D. +** +** <li> One or more transactions must have been written to the current wal +** file since it was created on disk (by any connection). This means +** that a snapshot cannot be taken on a wal mode database with no wal +** file immediately after it is first opened. At least one transaction +** must be written to it first. +** </ul> +** +** This function may also return SQLITE_NOMEM. If it is called with the +** database handle in autocommit mode but fails for some other reason, +** whether or not a read transaction is opened on schema S is undefined. +** +** The [sqlite3_snapshot] object returned from a successful call to +** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] +** to avoid a memory leak. +** +** The [sqlite3_snapshot_get()] interface is only available when the +** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. +*/ +SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( + sqlite3 *db, + const char *zSchema, + sqlite3_snapshot **ppSnapshot +); + +/* +** CAPI3REF: Start a read transaction on an historical snapshot +** METHOD: sqlite3_snapshot +** +** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read +** transaction or upgrades an existing one for schema S of +** [database connection] D such that the read transaction refers to +** historical [snapshot] P, rather than the most recent change to the +** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK +** on success or an appropriate [error code] if it fails. +** +** ^In order to succeed, the database connection must not be in +** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there +** is already a read transaction open on schema S, then the database handle +** must have no active statements (SELECT statements that have been passed +** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). +** SQLITE_ERROR is returned if either of these conditions is violated, or +** if schema S does not exist, or if the snapshot object is invalid. +** +** ^A call to sqlite3_snapshot_open() will fail to open if the specified +** snapshot has been overwritten by a [checkpoint]. In this case +** SQLITE_ERROR_SNAPSHOT is returned. +** +** If there is already a read transaction open when this function is +** invoked, then the same read transaction remains open (on the same +** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT +** is returned. If another error code - for example SQLITE_PROTOCOL or an +** SQLITE_IOERR error code - is returned, then the final state of the +** read transaction is undefined. If SQLITE_OK is returned, then the +** read transaction is now open on database snapshot P. +** +** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the +** database connection D does not know that the database file for +** schema S is in [WAL mode]. A database connection might not know +** that the database file is in [WAL mode] if there has been no prior +** I/O on that database connection, or if the database entered [WAL mode] +** after the most recent I/O on the database connection.)^ +** (Hint: Run "[PRAGMA application_id]" against a newly opened +** database connection in order to make it ready to use snapshots.) +** +** The [sqlite3_snapshot_open()] interface is only available when the +** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. +*/ +SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( + sqlite3 *db, + const char *zSchema, + sqlite3_snapshot *pSnapshot +); + +/* +** CAPI3REF: Destroy a snapshot +** DESTRUCTOR: sqlite3_snapshot +** +** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. +** The application must eventually free every [sqlite3_snapshot] object +** using this routine to avoid a memory leak. +** +** The [sqlite3_snapshot_free()] interface is only available when the +** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. +*/ +SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); + +/* +** CAPI3REF: Compare the ages of two snapshot handles. +** METHOD: sqlite3_snapshot +** +** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages +** of two valid snapshot handles. +** +** If the two snapshot handles are not associated with the same database +** file, the result of the comparison is undefined. +** +** Additionally, the result of the comparison is only valid if both of the +** snapshot handles were obtained by calling sqlite3_snapshot_get() since the +** last time the wal file was deleted. The wal file is deleted when the +** database is changed back to rollback mode or when the number of database +** clients drops to zero. If either snapshot handle was obtained before the +** wal file was last deleted, the value returned by this function +** is undefined. +** +** Otherwise, this API returns a negative value if P1 refers to an older +** snapshot than P2, zero if the two handles refer to the same database +** snapshot, and a positive value if P1 is a newer snapshot than P2. +** +** This interface is only available if SQLite is compiled with the +** [SQLITE_ENABLE_SNAPSHOT] option. +*/ +SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( + sqlite3_snapshot *p1, + sqlite3_snapshot *p2 +); + +/* +** CAPI3REF: Recover snapshots from a wal file +** METHOD: sqlite3_snapshot +** +** If a [WAL file] remains on disk after all database connections close +** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] +** or because the last process to have the database opened exited without +** calling [sqlite3_close()]) and a new connection is subsequently opened +** on that database and [WAL file], the [sqlite3_snapshot_open()] interface +** will only be able to open the last transaction added to the WAL file +** even though the WAL file contains other valid transactions. +** +** This function attempts to scan the WAL file associated with database zDb +** of database handle db and make all valid snapshots available to +** sqlite3_snapshot_open(). It is an error if there is already a read +** transaction open on the database, or if the database is not a WAL mode +** database. +** +** SQLITE_OK is returned if successful, or an SQLite error code otherwise. +** +** This interface is only available if SQLite is compiled with the +** [SQLITE_ENABLE_SNAPSHOT] option. +*/ +SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); + +/* +** CAPI3REF: Serialize a database +** +** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory +** that is a serialization of the S database on [database connection] D. +** If P is not a NULL pointer, then the size of the database in bytes +** is written into *P. +** +** For an ordinary on-disk database file, the serialization is just a +** copy of the disk file. For an in-memory database or a "TEMP" database, +** the serialization is the same sequence of bytes which would be written +** to disk if that database where backed up to disk. +** +** The usual case is that sqlite3_serialize() copies the serialization of +** the database into memory obtained from [sqlite3_malloc64()] and returns +** a pointer to that memory. The caller is responsible for freeing the +** returned value to avoid a memory leak. However, if the F argument +** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations +** are made, and the sqlite3_serialize() function will return a pointer +** to the contiguous memory representation of the database that SQLite +** is currently using for that database, or NULL if the no such contiguous +** memory representation of the database exists. A contiguous memory +** representation of the database will usually only exist if there has +** been a prior call to [sqlite3_deserialize(D,S,...)] with the same +** values of D and S. +** The size of the database is written into *P even if the +** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy +** of the database exists. +** +** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the +** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory +** allocation error occurs. +** +** This interface is omitted if SQLite is compiled with the +** [SQLITE_OMIT_DESERIALIZE] option. +*/ +unsigned char *sqlite3_serialize( + sqlite3 *db, /* The database connection */ + const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ + sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ + unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ +); + +/* +** CAPI3REF: Flags for sqlite3_serialize +** +** Zero or more of the following constants can be OR-ed together for +** the F argument to [sqlite3_serialize(D,S,P,F)]. +** +** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return +** a pointer to contiguous in-memory database that it is currently using, +** without making a copy of the database. If SQLite is not currently using +** a contiguous in-memory database, then this option causes +** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be +** using a contiguous in-memory database if it has been initialized by a +** prior call to [sqlite3_deserialize()]. +*/ +#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ + +/* +** CAPI3REF: Deserialize a database +** +** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the +** [database connection] D to disconnect from database S and then +** reopen S as an in-memory database based on the serialization contained +** in P. The serialized database P is N bytes in size. M is the size of +** the buffer P, which might be larger than N. If M is larger than N, and +** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is +** permitted to add content to the in-memory database as long as the total +** size does not exceed M bytes. +** +** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will +** invoke sqlite3_free() on the serialization buffer when the database +** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then +** SQLite will try to increase the buffer size using sqlite3_realloc64() +** if writes on the database cause it to grow larger than M bytes. +** +** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the +** database is currently in a read transaction or is involved in a backup +** operation. +** +** It is not possible to deserialized into the TEMP database. If the +** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the +** function returns SQLITE_ERROR. +** +** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the +** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then +** [sqlite3_free()] is invoked on argument P prior to returning. +** +** This interface is omitted if SQLite is compiled with the +** [SQLITE_OMIT_DESERIALIZE] option. +*/ +int sqlite3_deserialize( + sqlite3 *db, /* The database connection */ + const char *zSchema, /* Which DB to reopen with the deserialization */ + unsigned char *pData, /* The serialized database content */ + sqlite3_int64 szDb, /* Number bytes in the deserialization */ + sqlite3_int64 szBuf, /* Total size of buffer pData[] */ + unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ +); + +/* +** CAPI3REF: Flags for sqlite3_deserialize() +** +** The following are allowed values for 6th argument (the F argument) to +** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. +** +** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization +** in the P argument is held in memory obtained from [sqlite3_malloc64()] +** and that SQLite should take ownership of this memory and automatically +** free it when it has finished using it. Without this flag, the caller +** is responsible for freeing any dynamically allocated memory. +** +** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to +** grow the size of the database using calls to [sqlite3_realloc64()]. This +** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. +** Without this flag, the deserialized database cannot increase in size beyond +** the number of bytes specified by the M parameter. +** +** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database +** should be treated as read-only. +*/ +#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ +#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ +#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ + +/* +** Undo the hack that converts floating point types to integer for +** builds on processors without floating point support. +*/ +#ifdef SQLITE_OMIT_FLOATING_POINT +# undef double +#endif + +#ifdef __cplusplus +} /* End of the 'extern "C"' block */ +#endif +#endif /* SQLITE3_H */ |