SQLite

/*
** The default size of a disk sector
*/
#ifndef PAGER_SECTOR_SIZE
# define PAGER_SECTOR_SIZE 512
#endif

/*
** Return an integer that indices the type of lock currently held
** by this handle.  (Used for testing and analysis only.)
*/
static int os2LockState( OsFile *id ){
  return ((os2File*)id)->locktype;
}

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and it's journal file) that the sector size will be the
** same for both.
*/
static int os2SectorSize(OsFile *id){
  return PAGER_SECTOR_SIZE;
}

/*
** This vector defines all the methods that can operate on an OsFile
** for os2.
*/
static const IoMethod sqlite3Os2IoMethod = {
  os2Close,
  os2OpenDirectory,
  os2Read,
  os2Write,
  os2Seek,
  os2Truncate,
  os2Sync,
  os2SetFullSync,
  os2FileHandle,
  os2FileSize,
  os2Lock,
  os2Unlock,
  os2LockState,
  os2CheckReservedLock,
  os2SectorSize,
};

/*
** Allocate memory for an OsFile.  Initialize the new OsFile
** to the value given in pInit and return a pointer to the new
** OsFile.  If we run out of memory, close the file and return NULL.
*/

/*
** Return an integer that indices the type of lock currently held
** by this handle.  (Used for testing and analysis only.)
*/
static int unixLockState(OsFile *id){
  return ((unixFile*)id)->locktype;
}

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and it's journal file) that the sector size will be the
** same for both.
*/
static int unixSectorSize(OsFile *id){
  return PAGER_SECTOR_SIZE;
}

/*
** This vector defines all the methods that can operate on an OsFile
** for unix.
*/
static const IoMethod sqlite3UnixIoMethod = {
  unixClose,
  unixOpenDirectory,
  unixRead,
  unixWrite,
  unixSeek,
  unixTruncate,
  unixSync,
  unixSetFullSync,
  unixFileHandle,
  unixFileSize,
  unixLock,
  unixUnlock,
  unixLockState,
  unixCheckReservedLock,
  unixSectorSize,
};

#ifdef SQLITE_ENABLE_LOCKING_STYLE
/*
 ** This vector defines all the methods that can operate on an OsFile
 ** for unix with AFP style file locking.
 */

    unixSetFullSync,
    unixFileHandle,
    unixFileSize,
    afpUnixLock,
    afpUnixUnlock,
    unixLockState,
    afpUnixCheckReservedLock,
    unixSectorSize,
};

/*
 ** This vector defines all the methods that can operate on an OsFile
 ** for unix with flock() style file locking.
 */
static const IoMethod sqlite3FlockLockingUnixIoMethod = {

    unixSetFullSync,
    unixFileHandle,
    unixFileSize,
    flockUnixLock,
    flockUnixUnlock,
    unixLockState,
    flockUnixCheckReservedLock,
    unixSectorSize,
};

/*
 ** This vector defines all the methods that can operate on an OsFile
 ** for unix with dotlock style file locking.
 */
static const IoMethod sqlite3DotlockLockingUnixIoMethod = {

    unixSetFullSync,
    unixFileHandle,
    unixFileSize,
    dotlockUnixLock,
    dotlockUnixUnlock,
    unixLockState,
    dotlockUnixCheckReservedLock,
    unixSectorSize,
};

/*
 ** This vector defines all the methods that can operate on an OsFile
 ** for unix with dotlock style file locking.
 */
static const IoMethod sqlite3NolockLockingUnixIoMethod = {

  unixSetFullSync,
  unixFileHandle,
  unixFileSize,
  nolockUnixLock,
  nolockUnixUnlock,
  unixLockState,
  nolockUnixCheckReservedLock,
  unixSectorSize,
};

#endif /* SQLITE_ENABLE_LOCKING_STYLE */

/*
** Allocate memory for a new unixFile and initialize that unixFile.
** Write a pointer to the new unixFile into *pId.

/*
** Return an integer that indices the type of lock currently held
** by this handle.  (Used for testing and analysis only.)
*/
static int winLockState(OsFile *id){
  return ((winFile*)id)->locktype;
}

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and it's journal file) that the sector size will be the
** same for both.
*/
static int winSectorSize(OsFile *id){
  return PAGER_SECTOR_SIZE;
}

/*
** This vector defines all the methods that can operate on an OsFile
** for win32.
*/
static const IoMethod sqlite3WinIoMethod = {
  winClose,
  winOpenDirectory,
  winRead,
  winWrite,
  winSeek,
  winTruncate,
  winSync,
  winSetFullSync,
  winFileHandle,
  winFileSize,
  winLock,
  winUnlock,
  winLockState,
  winCheckReservedLock,
  winSectorSize,
};

/*
** Allocate memory for an OsFile.  Initialize the new OsFile
** to the value given in pInit and return a pointer to the new
** OsFile.  If we run out of memory, close the file and return NULL.
*/