SQLite

** 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 1.359 2008/06/26 15:04:58 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++.

**
** On success, [SQLITE_OK] is returned and the new [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 connection] error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
**
** If the row that a BLOB handle points to is modified by an
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
** then the BLOB handle is marked as "expired".
** This is true if any column of the row is changed, even a column
** other than the one the BLOB handle is open on.
** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
** a expired BLOB handle fail with an return code of [SQLITE_ABORT].
** Changes written into a BLOB prior to the BLOB expiring are not
** rollback by the expiration of the BLOB.  Such changes will eventually
** commit if the transaction continues to completion.
**
** INVARIANTS:
**
** {F17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)]
**          interface shall open an [sqlite3_blob] object P on the BLOB
**          in column C of the table T in the database B on
**          the [database connection] D.
**
** {F17814} A successful invocation of [sqlite3_blob_open(D,...)] shall start
**          a new transaction on the [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 shall open
**          the BLOB for read and write access if and only if the F
**          parameter is non-zero.
**
** {F17819} The [sqlite3_blob_open()] interface shall return [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)] shall return
**          information appropriate for that error.
**
** {F17824} If any column in the row that a [sqlite3_blob] has open is
**          changed by a separate [UPDATE] or [DELETE] statement or by
**          an [ON CONFLICT] side effect, then the [sqlite3_blob] shall
**          be marked as invalid.
*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
  const char *zTable,
  const char *zColumn,
  sqlite3_int64 iRow,

**
** {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 [autocommit mode].
**
** {F17839} The [sqlite3_blob_close(P)] interfaces shall close 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}

** This function is used to read data from an open [BLOB handle] into a
** caller-supplied buffer. N bytes of data are copied into buffer Z
** from the open BLOB, starting at offset iOffset.
**
** If offset iOffset is less than N bytes from the end of the BLOB,
** [SQLITE_ERROR] is returned and no data is read.  If N or iOffset is
** less than zero, [SQLITE_ERROR] is returned and no data is read.
**
** An attempt to read from an expired [BLOB handle] fails with an
** error code of [SQLITE_ABORT].
**
** On success, SQLITE_OK is returned.
** Otherwise, an [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17853} A successful invocation of [sqlite3_blob_read(P,Z,N,X)] 
**          shall reads N bytes of data out of the BLOB referenced by
**          [BLOB handle] P beginning at offset X and store those 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 shall leave the
**          Z buffer unchanged and return [SQLITE_ERROR].
**
** {F17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero
**          then the function shall leave the Z buffer unchanged
**          and return [SQLITE_ERROR].
**
** {F17862} The [sqlite3_blob_read(P,Z,N,X)] interface shall return [SQLITE_OK]
**          if N bytes are successfully read into buffer Z.
**
** {F17863} If the [BLOB handle] P is expired and X and N are within bounds
**          then [sqlite3_blob_read(P,Z,N,X)] shall leave the Z buffer
**          unchanged and return [SQLITE_ABORT].
**
** {F17865} If the requested read could not be completed,
**          the [sqlite3_blob_read(P,Z,N,X)] interface shall return an
**          appropriate [error code] or [extended error code].
**
** {F17868} If an error occurs during evaluation of [sqlite3_blob_read(P,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return
**          information appropriate for that error, where D is the
**          [database connection] that was used to open the [BLOB handle] P.
*/
int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*
** CAPI3REF: Write Data Into A BLOB Incrementally {F17870}

**
** 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.
**
** An attempt to write to an expired [BLOB handle] fails with an
** error code of [SQLITE_ABORT].  Writes to the BLOB that occurred
** before the [BLOB handle] expired are not rolled back by the
** expiration of the handle, though of course those changes might
** have been overwritten by the statement that expired the BLOB handle
** or by other independent statements.
**
** On success, SQLITE_OK is returned.
** Otherwise, an  [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17873} A successful invocation of [sqlite3_blob_write(P,Z,N,X)]
**          shall write N bytes of data from buffer Z into the BLOB 
**          referenced by [BLOB handle] P beginning at offset X into
**          the BLOB.
**
** {F17874} In the absence of other overridding changes, the changes
**          written to a BLOB by [sqlite3_blob_write()] shall
**          remain in effect after the associated [BLOB handle] expires.
**
** {F17875} If the [BLOB handle] P was opened for reading only then
**          an invocation of [sqlite3_blob_write(P,Z,N,X)] shall leave
**          the referenced BLOB unchanged and return [SQLITE_READONLY].
**
** {F17876} If the size of the BLOB referenced by [BLOB handle] P is
**          less than N+X bytes then [sqlite3_blob_write(P,Z,N,X)] shall
**          leave the BLOB unchanged and return [SQLITE_ERROR].
**
** {F17877} If the [BLOB handle] P is expired and X and N are within bounds
**          then [sqlite3_blob_read(P,Z,N,X)] shall leave the BLOB
**          unchanged and return [SQLITE_ABORT].
**
** {F17879} If X or N are less than zero then [sqlite3_blob_write(P,Z,N,X)]
**          shall leave the BLOB referenced by [BLOB handle] P unchanged
**          and return [SQLITE_ERROR].
**
** {F17882} The [sqlite3_blob_write(P,Z,N,X)] interface shall return
**          [SQLITE_OK] if N bytes where successfully written into the BLOB.
**
** {F17885} If the requested write could not be completed,
**          the [sqlite3_blob_write(P,Z,N,X)] interface shall return 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)] shall return
**          information appropriate for that error.
*/
int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF: Virtual File System Objects {F11200}
**