** 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.
**
** @(#) $Id: sqlite.h.in,v 1.286 2008/02/21 02:09:45 drh Exp $
*/
#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++.
................................................................................
**          with which the header file is associated.
**
** {F10014} The SQLITE_VERSION_NUMBER #define resolves to an integer
**          with the value  (X*1000000 + Y*1000 + Z) where X, Y, and
**          Z are the major version, minor version, and release number.
*/
#define SQLITE_VERSION         "--VERS--"
#define SQLITE_VERSION_NUMBER --VERSION-NUMBER--

/*
** CAPI3REF: Run-Time Library Version Numbers {F10020}
** KEYWORDS: sqlite3_version
**
** These features provide the same information as the [SQLITE_VERSION]
** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated
................................................................................
**          allocated using the equivalent of [sqlite3_mprintf()] and
**          *errmsg is made to point to that message.
**
** {F12134} The [sqlite3_exec()] routine does not change the value of
**          *errmsg if errmsg is NULL or if there are no errors.
**
** {F12137} The [sqlite3_exec()] function sets the error code and message
**          accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].

**
** LIMITATIONS:
**
** {U12141} The first parameter to [sqlite3_exec()] must be an valid and open
**          [database connection].
**
** {U12142} The database connection must not be closed while
................................................................................
** versions of SQLite.  Additional fields may be appended to this
** object when the iVersion value is 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 vfs modules 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.
**
** The pNext field is the only fields in the sqlite3_vfs 
** structure that SQLite will ever modify.  SQLite will only access
................................................................................
** subsequent calls to other SQLite interface functions.
**
** INVARIANTS:
**
** {F12801} The [sqlite3_errcode(D)] interface returns the numeric
**          [SQLITE_OK | result code] or
**          [SQLITE_IOERR_READ | extended result code]
**          for the most recent failed interface call associated
**          with [sqlite3] handle D.
**
** {U12802} If a prior API call failed but the most recent API call
**          succeeded, the return value from [sqlite3_errcode()],
**          [sqlite3_errmsg()], and [sqlite3_errmsg16()] are undefined.
**
** {F12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)]
**          interfaces return English-language text that describes
**          the error in the mostly recently failed interface call,
**          encoded as either UTF8 or UTF16 respectively.
**
** {U12804} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()]
**          are only valid until the next SQLite interface call.
**
** {F12807} Calls to [sqlite3_errcode()], [sqlite3_errmsg()], and
**          [sqlite3_errmsg16()] themselves do not affect the
**          results of future invocations of these routines.
**
** {F12808} Calls to API routines that do not return an error code
**          (example: [sqlite3_data_count()]) do not
**          change the error code or message returned by
**          [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].
**
** {F12809} Interfaces that are not associated with a specific
................................................................................
*/
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;

/*



** A module is a class of virtual tables.  Each module is defined
** by an instance of the following structure.  This structure consists
** mostly of methods for the module.
*/
struct sqlite3_module {
  int iVersion;
  int (*xCreate)(sqlite3*, void *pAux,
................................................................................
                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
                       void **ppArg);

  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
};

/*



** The sqlite3_index_info structure and its substructures is used to
** pass information into and receive the reply from the xBestIndex
** method of an sqlite3_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
................................................................................
#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

/*


** This routine is used to register a new module name with an SQLite
** connection.  Module names must be registered before creating new
** virtual tables on the module, or before using preexisting virtual
** tables of the module.
*/
int sqlite3_create_module(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *,    /* Methods for the module */
  void *                     /* Client data for xCreate/xConnect */
);

/*


** This routine is identical to the sqlite3_create_module() method above,
** except that it allows a destructor function to be specified. It is
** even more experimental than the rest of the virtual tables API.
*/
int sqlite3_create_module_v2(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *,    /* Methods for the module */
  void *,                    /* Client data for xCreate/xConnect */
  void(*xDestroy)(void*)     /* Module destructor function */
);

/*



** Every module implementation uses a subclass of the following structure
** to describe a particular instance of the module.  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
................................................................................
struct sqlite3_vtab {
  const sqlite3_module *pModule;  /* The module for this virtual table */
  int nRef;                       /* Used internally */
  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
  /* Virtual table implementations will typically add additional fields */
};





/* Every 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
** xOpen method 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 */
};

/*


** The xCreate and xConnect methods of a module use the following API
** to declare the format (the names and datatypes of the columns) of
** the virtual tables they implement.
*/
int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);

/*


** Virtual tables can provide alternative implementations of functions
** using the xFindFunction method.  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
................................................................................
**
****** EXPERIMENTAL - subject to change without notice **************
*/

/*
** CAPI3REF: A Handle To An Open BLOB {F17800}
**
** An instance of the following opaque structure is used to 
** represent an blob-handle.  A blob-handle is 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 {F17810}
**
** {F17811} This interfaces opens a 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> {END}
**
** {F17812} If the flags parameter is non-zero, the blob is opened for 
** read and write access. If it is zero, the blob is opened for read 
** access. {END}
**
** {F17813} On success, [SQLITE_OK] is returned and the new 
** [sqlite3_blob | blob handle] is written to *ppBlob. 
** {F17814} Otherwise an error code is returned and 
** any value written to *ppBlob should not be used by the caller.
** {F17815} This function sets the database-handle error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
** <todo>We should go through and mark all interfaces that behave this
** way with a similar statement</todo>




















*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
  const char *zTable,
  const char *zColumn,
  sqlite3_int64 iRow,
................................................................................
);

/*
** CAPI3REF:  Close A BLOB Handle {F17830}
**
** Close an open [sqlite3_blob | blob handle].
**
** {F17831} Closing a BLOB shall cause the current transaction to commit
** if there are no other BLOBs, no pending prepared statements, and the
** database connection is in autocommit mode.
** {F17832} If any writes were made to the BLOB, they might be held in cache
** until the close operation if they will fit. {END}
** Closing the BLOB often forces the changes
** out to disk and so if any I/O errors occur, they will likely occur
** at the time when the BLOB is closed.  {F17833} Any errors that occur during
** closing are reported as a non-zero return value.
**
** {F17839} The BLOB is closed unconditionally.  Even if this routine returns
** an error code, the BLOB is still closed.


















*/
int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF:  Return The Size Of An Open BLOB {F17805}
**
** {F16806} Return the size in bytes of the blob accessible via the open 
** [sqlite3_blob | blob-handle] passed as an argument.






*/
int sqlite3_blob_bytes(sqlite3_blob *);

/*
** CAPI3REF:  Read Data From A BLOB Incrementally {F17850}
**
** This function is used to read data from an open 
** [sqlite3_blob | blob-handle] into a caller supplied buffer.
** {F17851} n bytes of data are copied into buffer
** z from the open blob, starting at offset iOffset.
**
** {F17852} If offset iOffset is less than n bytes from the end of the blob, 
** [SQLITE_ERROR] is returned and no data is read.  {F17853} If n is
** less than zero [SQLITE_ERROR] is returned and no data is read.
**
** {F17854} On success, SQLITE_OK is returned. Otherwise, an 
** [error code] or an [extended error code] is returned.



























*/
int sqlite3_blob_read(sqlite3_blob *, void *z, int n, int iOffset);

/*
** CAPI3REF:  Write Data Into A BLOB Incrementally {F17870}
**
** This function is used to write data into an open 
** [sqlite3_blob | blob-handle] from a user supplied buffer.
** {F17871} n bytes of data are copied from the buffer
** pointed to by z into the open blob, starting at offset iOffset.
**
** {F17872} If the [sqlite3_blob | 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].
**
** {F17873} This function may only modify the contents of the blob; it is
** not possible to increase the size of a blob using this API.
** {F17874} If offset iOffset is less than n bytes from the end of the blob, 
** [SQLITE_ERROR] is returned and no data is written.  {F17875} If n is
** less than zero [SQLITE_ERROR] is returned and no data is written.
**
** {F17876} On success, SQLITE_OK is returned. Otherwise, an 
** [error code] or an [extended error code] is returned.































*/
int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF:  Virtual File System Objects {F11200}
**
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
** that SQLite uses to interact
** with the underlying operating system.  Most 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.
**
** {F11201} The sqlite3_vfs_find() interface returns a pointer to 
** a VFS given its name.  {F11202} Names are case sensitive.
** {F11203} Names are zero-terminated UTF-8 strings.
** {F11204} If there is no match, a NULL
** pointer is returned. {F11205} If zVfsName is NULL then the default 
** VFS is returned. {END}
**
** {F11210} New VFSes are registered with sqlite3_vfs_register().
** {F11211} Each new VFS becomes the default VFS if the makeDflt flag is set.
** {F11212} The same VFS can be registered multiple times without injury.
** {F11213} To make an existing VFS into the default VFS, register it again
** with the makeDflt flag set. {U11214} If two different VFSes with the
** same name are registered, the behavior is undefined.  {U11215} If a
** VFS is registered with a name that is NULL or an empty string,
** then the behavior is undefined.
** 
** {F11220} Unregister a VFS with the sqlite3_vfs_unregister() interface.
** {F11221} 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 {F17000}

** 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.
**
** @(#) $Id: sqlite.h.in,v 1.287 2008/02/21 20:17:07 drh Exp $
*/
#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++.
................................................................................
**          with which the header file is associated.
**
** {F10014} The SQLITE_VERSION_NUMBER #define resolves to an integer
**          with the value  (X*1000000 + Y*1000 + Z) where X, Y, and
**          Z are the major version, minor version, and release number.
*/
#define SQLITE_VERSION         "--VERS--"
#define SQLITE_VERSION_NUMBER  --VERSION-NUMBER--

/*
** CAPI3REF: Run-Time Library Version Numbers {F10020}
** KEYWORDS: sqlite3_version
**
** These features provide the same information as the [SQLITE_VERSION]
** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated
................................................................................
**          allocated using the equivalent of [sqlite3_mprintf()] and
**          *errmsg is made to point to that message.
**
** {F12134} The [sqlite3_exec()] routine does not change the value of
**          *errmsg if errmsg is NULL or if there are no errors.
**
** {F12137} The [sqlite3_exec()] function sets the error code and message
**          accessible via [sqlite3_errcode()], [sqlite3_errmsg()], and
**          [sqlite3_errmsg16()].
**
** LIMITATIONS:
**
** {U12141} The first parameter to [sqlite3_exec()] must be an valid and open
**          [database connection].
**
** {U12142} The database connection must not be closed while
................................................................................
** versions of SQLite.  Additional fields may be appended to this
** object when the iVersion value is 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.
**
** The pNext field is the only fields in the sqlite3_vfs 
** structure that SQLite will ever modify.  SQLite will only access
................................................................................
** subsequent calls to other SQLite interface functions.
**
** INVARIANTS:
**
** {F12801} The [sqlite3_errcode(D)] interface returns the numeric
**          [SQLITE_OK | result code] or
**          [SQLITE_IOERR_READ | extended result code]
**          for the most recently failed interface call associated
**          with [database connection] D.




**
** {F12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)]
**          interfaces return English-language text that describes
**          the error in the mostly recently failed interface call,
**          encoded as either UTF8 or UTF16 respectively.
**
** {F12807} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()]
**          are valid until the next SQLite interface call.




**
** {F12808} Calls to API routines that do not return an error code
**          (example: [sqlite3_data_count()]) do not
**          change the error code or message returned by
**          [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].
**
** {F12809} Interfaces that are not associated with a specific
................................................................................
*/
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 {F18000}
** KEYWORDS: sqlite3_module
**
** A module is a class of virtual tables.  Each module is defined
** by an instance of the following structure.  This structure consists
** mostly of methods for the module.
*/
struct sqlite3_module {
  int iVersion;
  int (*xCreate)(sqlite3*, void *pAux,
................................................................................
                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
                       void **ppArg);

  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
};

/*
** CAPI3REF: Virtual Table Indexing Information {F18100}
** KEYWORDS: sqlite3_index_info
**
** The sqlite3_index_info structure and its substructures is used to
** pass information into and receive the reply from the xBestIndex
** method of an sqlite3_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
................................................................................
#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

/*
** CAPI3REF: Register A Virtual Table Implementation {F18200}
**
** This routine is used to register a new module name with an SQLite
** connection.  Module names must be registered before creating new
** virtual tables on the module, or before using preexisting virtual
** tables of the module.
*/
int sqlite3_create_module(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *,    /* Methods for the module */
  void *                     /* Client data for xCreate/xConnect */
);

/*
** CAPI3REF: Register A Virtual Table Implementation {F18210}
**
** This routine is identical to the sqlite3_create_module() method above,
** except that it allows a destructor function to be specified. It is
** even more experimental than the rest of the virtual tables API.
*/
int sqlite3_create_module_v2(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *,    /* Methods for the module */
  void *,                    /* Client data for xCreate/xConnect */
  void(*xDestroy)(void*)     /* Module destructor function */
);

/*
** CAPI3REF: Virtual Table Instance Object {F18010}
** KEYWORDS: sqlite3_vtab
**
** Every module implementation uses a subclass of the following structure
** to describe a particular instance of the module.  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
................................................................................
struct sqlite3_vtab {
  const sqlite3_module *pModule;  /* The module for this virtual table */
  int nRef;                       /* Used internally */
  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
  /* Virtual table implementations will typically add additional fields */
};

/*
** CAPI3REF: Virtual Table Cursor Object  {F18020}
** KEYWORDS: sqlite3_vtab_cursor
**
** Every 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
** xOpen method 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 {F18280}
**
** The xCreate and xConnect methods of a module use the following API
** to declare the format (the names and datatypes of the columns) of
** the virtual tables they implement.
*/
int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);

/*
** CAPI3REF: Overload A Function For A Virtual Table {F18300}
**
** Virtual tables can provide alternative implementations of functions
** using the xFindFunction method.  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
................................................................................
**
****** EXPERIMENTAL - subject to change without notice **************
*/

/*
** CAPI3REF: A Handle To An Open BLOB {F17800}
**
** An instance of this object represents an open BLOB on which
** incremental I/O can be preformed.
** 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 {F17810}
**
** This interfaces opens a 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> {END}
**
** If the flags parameter is non-zero, the blob is opened for 
** read and write access. If it is zero, the blob is opened for read 
** access.
**
** On success, [SQLITE_OK] is returned and the new 
** [sqlite3_blob | blob handle] is written to *ppBlob. 
** Otherwise an error code is returned and 
** any value written to *ppBlob should not be used by the caller.
** This function sets the database-handle error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
** 
** INVARIANTS:
**
** {F17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)]
**          interface opens an [sqlite3_blob] object P on the blob
**          in column C of table T in database B on [database connection] D.
**
** {F17814} A successful invocation of [sqlite3_blob_open(D,...)] starts
**          a new transaction on [database connection] D if that connection
**          is not already in a transaction.
**
** {F17816} The [sqlite3_blob_open(D,B,T,C,R,F,P)] interface opens the blob
**          for read and write access if and only if the F parameter
**          is non-zero.
**
** {F17819} The [sqlite3_blob_open()] interface returns [SQLITE_OK] on 
**          success and an appropriate [error code] on failure.
**
** {F17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
**          information approprate for that error.
*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
  const char *zTable,
  const char *zColumn,
  sqlite3_int64 iRow,
................................................................................
);

/*
** CAPI3REF:  Close A BLOB Handle {F17830}
**
** Close an open [sqlite3_blob | blob handle].
**
** Closing a BLOB shall cause the current transaction to commit
** if there are no other BLOBs, no pending prepared statements, and the
** database connection is in autocommit mode.
** If any writes were made to the BLOB, they might be held in cache
** until the close operation if they will fit. {END}
** Closing the BLOB often forces the changes
** out to disk and so if any I/O errors occur, they will likely occur
** at the time when the BLOB is closed.  {F17833} Any errors that occur during
** closing are reported as a non-zero return value.
**
** The BLOB is closed unconditionally.  Even if this routine returns
** an error code, the BLOB is still closed.
**
** INVARIANTS:
**
** {F17833} The [sqlite3_blob_close(P)] interface closes an
**          [sqlite3_blob] object P previously opened using
**          [sqlite3_blob_open()].
**
** {F17836} Closing an [sqlite3_blob] object using
**          [sqlite3_blob_close()] shall cause the current transaction to
**          commit if there are no other open [sqlite3_blob] objects
**          or [prepared statements] on the same [database connection] and
**          the [database connection] is in
**          [sqlite3_get_autocommit | autocommit mode].
**
** {F17839} The [sqlite3_blob_close(P)] interfaces closes the 
**          [sqlite3_blob] object P unconditionally, even if
**          [sqlite3_blob_close(P)] returns something other than [SQLITE_OK].
**          
*/
int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF:  Return The Size Of An Open BLOB {F17840}
**
** Return the size in bytes of the blob accessible via the open 
** [sqlite3_blob] object in its only argument.
**
** INVARIANTS:
**
** {F17843} The [sqlite3_blob_bytes(P)] interface returns the size
**          in bytes of the BLOB that the [sqlite3_blob] object P
**          refers to.
*/
int sqlite3_blob_bytes(sqlite3_blob *);

/*
** CAPI3REF:  Read Data From A BLOB Incrementally {F17850}
**
** This function is used to read data from an open 
** [sqlite3_blob | 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.
**
** On success, SQLITE_OK is returned. Otherwise, an 
** [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17853} The [sqlite3_blob_read(P,Z,N,X)] interface reads N bytes
**          beginning at offset X from
**          the blob that [sqlite3_blob] object P refers to
**          and writes those N bytes into buffer Z.
**
** {F17856} In [sqlite3_blob_read(P,Z,N,X)] if the size of the blob
**          is less than N+X bytes, then the function returns [SQLITE_ERROR]
**          and nothing is read from the blob.
**
** {F17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero
**          then the function returns [SQLITE_ERROR]
**          and nothing is read from the blob.
**
** {F17862} The [sqlite3_blob_read(P,Z,N,X)] interface returns [SQLITE_OK]
**          if N bytes where successfully read into buffer Z.
**
** {F17865} If the requested read could not be completed,
**          the [sqlite3_blob_read(P,Z,N,X)] interface returns an
**          appropriate [error code] or [extended error code].
**
** {F17868} If an error occurs during evaluation of [sqlite3_blob_read(D,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
**          information approprate for that error.
*/
int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*
** CAPI3REF:  Write Data Into A BLOB Incrementally {F17870}
**
** This function is used to write data into an open 
** [sqlite3_blob | blob-handle] from a user supplied buffer.
** n bytes of data are copied from the buffer
** pointed to by z into the open blob, starting at offset iOffset.
**
** If the [sqlite3_blob | 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.  If n is
** less than zero [SQLITE_ERROR] is returned and no data is written.
**
** On success, SQLITE_OK is returned. Otherwise, an 
** [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17873} The [sqlite3_blob_write(P,Z,N,X)] interface writes N bytes
**          from buffer Z into
**          the blob that [sqlite3_blob] object P refers to
**          beginning at an offset of X into the blob.
**
** {F17875} The [sqlite3_blob_write(P,Z,N,X)] interface returns
**          [SQLITE_READONLY] if the [sqlite3_blob] object P was
**          [sqlite3_blob_open | opened] for reading only.
**
** {F17876} In [sqlite3_blob_write(P,Z,N,X)] if the size of the blob
**          is less than N+X bytes, then the function returns [SQLITE_ERROR]
**          and nothing is written into the blob.
**
** {F17879} In [sqlite3_blob_write(P,Z,N,X)] if X or N is less than zero
**          then the function returns [SQLITE_ERROR]
**          and nothing is written into the blob.
**
** {F17882} The [sqlite3_blob_write(P,Z,N,X)] interface returns [SQLITE_OK]
**          if N bytes where successfully written into blob.
**
** {F17885} If the requested write could not be completed,
**          the [sqlite3_blob_write(P,Z,N,X)] interface returns an
**          appropriate [error code] or [extended error code].
**
** {F17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
**          information approprate for that error.
*/
int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF:  Virtual File System Objects {F11200}
**
** 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.
**
** INVARIANTS:
**
** {F11203} The [sqlite3_vfs_find(N)] interface returns a pointer to the
**          registered [sqlite3_vfs] object whose name exactly matches
**          the zero-terminated UTF-8 string N, or it returns NULL if
**          there is no match.
**
** {F11206} If the N parameter to [sqlite3_vfs_find(N)] is NULL then
**          the function returns a pointer to the default [sqlite3_vfs]
**          object if there is one, or NULL if there is no default 
**          [sqlite3_vfs] object.
**
** {F11209} The [sqlite3_vfs_register(P,F)] interface registers the
**          well-formed [sqlite3_vfs] object P using the name given
**          by the zName field of the object.
**
** {F11212} Using the [sqlite3_vfs_register(P,F)] interface to register
**          the same [sqlite3_vfs] object multiple times is a harmless no-op.
**
** {F11215} The [sqlite3_vfs_register(P,F)] interface makes the
**          the [sqlite3_vfs] object P the default [sqlite3_vfs] object
**          if F is non-zero.
**
** {F11218} The [sqlite3_vfs_unregister(P)] interface unregisters the
**          [sqlite3_vfs] object P so that it is no longer returned by
**          subsequent calls to [sqlite3_vfs_find()].
*/
sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
int sqlite3_vfs_unregister(sqlite3_vfs*);

/*
** CAPI3REF: Mutexes {F17000}