/*

** 2001 September 15

**

** The author disclaims copyright to this source code.  In place of

** a legal notice, here is a blessing:

**

**    May you do good and not evil.

**    May you find forgiveness for yourself and forgive others.

**    May you share freely, never taking more than you give.

**

*************************************************************************

** This header file defines the interface that the SQLite 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 suppose 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

/*

** Add the ability to override 'extern'

*/

#ifndef SQLITE_EXTERN

# define SQLITE_EXTERN extern

#endif

#ifndef SQLITE_API

# define SQLITE_API

#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 support 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, 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 an SHA1

** hash of the entire source tree.

**

** See also: [sqlite3_libversion()],

** [sqlite3_libversion_number()], [sqlite3_sourceid()],

** [sqlite_version()] and [sqlite_source_id()].

*/

#define SQLITE_VERSION        "3.7.13"

#define SQLITE_VERSION_NUMBER 3007013

#define SQLITE_SOURCE_ID      "2012-06-11 02:05:22 f5b5a13f7394dc143aa136f1d4faba6839eaa6dc"

/*

** 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 insure that the application is

** compiled with matching library and header files.

**

** <blockquote><pre>

** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );

** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==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.

**

** See also: [sqlite_version()] and [sqlite_source_id()].

*/

SQLITE_API SQLITE_EXTERN const char sqlite3_version[];

SQLITE_API const char *sqlite3_libversion(void);

SQLITE_API const char *sqlite3_sourceid(void);

SQLITE_API 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

SQLITE_API int sqlite3_compileoption_used(const char *zOptName);

SQLITE_API const char *sqlite3_compileoption_get(int N);

#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_MUTEX].  ^(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.

*/

SQLITE_API 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()]

** is its destructor.  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;

  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;

#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

**

** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.

** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is

** successfully destroyed and all associated resources are deallocated.

**

** Applications must [sqlite3_finalize | finalize] all [prepared statements]

** and [sqlite3_blob_close | close] all [BLOB handles] associated with

** the [sqlite3] object prior to attempting to close the object.  ^If

** sqlite3_close() is called on a [database connection] that still has

** outstanding [prepared statements] or [BLOB handles], then it returns

** SQLITE_BUSY.

**

** ^If [sqlite3_close()] is invoked while a transaction is open,

** the transaction is automatically rolled back.

**

** The C parameter to [sqlite3_close(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() with a NULL pointer argument is a 

** harmless no-op.

*/

SQLITE_API int sqlite3_close(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

**

** 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

** 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 insure that the 1st parameter to sqlite3_exec()

**      is a valid and open [database connection].

** <li> The application must not close [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>

*/

SQLITE_API 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: SQLITE_OK {error code} {error codes}

** KEYWORDS: {result code} {result codes}

**

** 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: [SQLITE_IOERR_READ | extended result codes],

** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].

*/

#define SQLITE_OK           0   /* Successful result */

/* beginning-of-error-codes */

#define SQLITE_ERROR        1   /* SQL error or missing database */

#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   /* Database is empty */

#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   /* Auxiliary database format error */

#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_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 error code} {extended error codes}

** KEYWORDS: {extended result code} {extended result codes}

**

** In its default configuration, SQLite API routines return one of 26 integer

** [SQLITE_OK | 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 and later) include

** support for additional result codes that provide more detailed information

** about errors. The extended result codes are enabled or disabled

** on a per database connection basis using the

** [sqlite3_extended_result_codes()] API.

**

** Some of the available extended result codes are listed here.

** One may expect the number of extended result codes will be expand

** over time.  Software that uses extended result codes should expect

** to see new result codes in future releases of SQLite.

**

** The SQLITE_OK result code will never be extended.  It will always

** be exactly zero.

*/

#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_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))

#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))

#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))

#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))

#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))

#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))

#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))

#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))

/*

** 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.

*/

#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_MASTER_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 */

/* Reserved:                         0x00F00000 */

/*

** CAPI3REF: Device Characteristics

**

** The xDeviceCharacteristics method of the [sqlite3_io_methods]

** object returns an integer which is a vector of the 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.

*/

#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

/*

** 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.

*/

#define SQLITE_LOCK_NONE          0

#define SQLITE_LOCK_SHARED        1

#define SQLITE_LOCK_RESERVED      2

#define SQLITE_LOCK_PENDING       3

#define SQLITE_LOCK_EXCLUSIVE     4

/*

** 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() increases the lock. xUnlock() decreases the lock.

** 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 [SQLITE_FCNTL_LOCKSTATE | 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]

** </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 */

  /* Additional methods may be added in future releases */

};

/*

** CAPI3REF: Standard File Control Opcodes

**

** These integer constants are opcodes for the xFileControl method

** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]

** interface.

**

** 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 used during testing and only needs to be supported when SQLITE_TEST

** is defined.

** <ul>

** <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_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 the [sqlite3_file_control()] documentation for

** additional information.

**

** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]

** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by

** SQLite and sent to all VFSes in place of a call to the xSync method

** when the database connection has [PRAGMA synchronous] set to OFF.)^

** Some specialized VFSes need this signal in order to operate correctly

** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 

** VFSes do not need this signal and 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 i 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 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_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