/*

** 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(

);

/*

** 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_IOERR_IN_PAGE (SQLITE_IOERR | (34<<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_NOTICE_RBU (SQLITE_NOTICE | (3<<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 {

};

/*

** 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.

**