os_os2.c

嵌入式数据系统软件！

    }
  }

  /* Acquire a shared lock
  */
  if( locktype==SHARED_LOCK && res == NO_ERROR ){
    assert( pFile->locktype==NO_LOCK );
    res = getReadLock(pFile);
    if( res == NO_ERROR ){
      newLocktype = SHARED_LOCK;
    }
    OSTRACE3( "LOCK %d acquire shared lock. res=%d\n", pFile->h, res );
  }

  /* Acquire a RESERVED lock
  */
  if( locktype==RESERVED_LOCK && res == NO_ERROR ){
    assert( pFile->locktype==SHARED_LOCK );
    LockArea.lOffset = RESERVED_BYTE;
    LockArea.lRange = 1L;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    if( res == NO_ERROR ){
      newLocktype = RESERVED_LOCK;
    }
    OSTRACE3( "LOCK %d acquire reserved lock. res=%d\n", pFile->h, res );
  }

  /* Acquire a PENDING lock
  */
  if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
    newLocktype = PENDING_LOCK;
    gotPendingLock = 0;
    OSTRACE2( "LOCK %d acquire pending lock. pending lock boolean unset.\n", pFile->h );
  }

  /* Acquire an EXCLUSIVE lock
  */
  if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
    assert( pFile->locktype>=SHARED_LOCK );
    res = unlockReadLock(pFile);
    OSTRACE2( "unreadlock = %d\n", res );
    LockArea.lOffset = SHARED_FIRST;
    LockArea.lRange = SHARED_SIZE;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    if( res == NO_ERROR ){
      newLocktype = EXCLUSIVE_LOCK;
    }else{
      OSTRACE2( "OS/2 error-code = %d\n", res );
      getReadLock(pFile);
    }
    OSTRACE3( "LOCK %d acquire exclusive lock.  res=%d\n", pFile->h, res );
  }

  /* If we are holding a PENDING lock that ought to be released, then
  ** release it now.
  */
  if( gotPendingLock && locktype==SHARED_LOCK ){
    int r;
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = PENDING_BYTE;
    UnlockArea.lRange = 1L;
    r = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "LOCK %d unlocking pending/is shared. r=%d\n", pFile->h, r );
  }

  /* Update the state of the lock has held in the file descriptor then
  ** return the appropriate result code.
  */
  if( res == NO_ERROR ){
    rc = SQLITE_OK;
  }else{
    OSTRACE4( "LOCK FAILED %d trying for %d but got %d\n", pFile->h,
              locktype, newLocktype );
    rc = SQLITE_BUSY;
  }
  pFile->locktype = newLocktype;
  OSTRACE3( "LOCK %d now %d\n", pFile->h, pFile->locktype );
  return rc;
}

/*
** This routine checks if there is a RESERVED lock held on the specified
** file by this or any other process. If such a lock is held, return
** non-zero, otherwise zero.
*/
int os2CheckReservedLock( sqlite3_file *id ){
  APIRET rc = NO_ERROR;
  os2File *pFile = (os2File*)id;
  assert( pFile!=0 );
  if( pFile->locktype>=RESERVED_LOCK ){
    rc = 1;
    OSTRACE3( "TEST WR-LOCK %d %d (local)\n", pFile->h, rc );
  }else{
    FILELOCK  LockArea,
              UnlockArea;
    memset(&LockArea, 0, sizeof(LockArea));
    memset(&UnlockArea, 0, sizeof(UnlockArea));
    LockArea.lOffset = RESERVED_BYTE;
    LockArea.lRange = 1L;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;
    rc = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "TEST WR-LOCK %d lock reserved byte rc=%d\n", pFile->h, rc );
    if( rc == NO_ERROR ){
      int r;
      LockArea.lOffset = 0L;
      LockArea.lRange = 0L;
      UnlockArea.lOffset = RESERVED_BYTE;
      UnlockArea.lRange = 1L;
      r = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
      OSTRACE3( "TEST WR-LOCK %d unlock reserved byte r=%d\n", pFile->h, r );
    }
    OSTRACE3( "TEST WR-LOCK %d %d (remote)\n", pFile->h, rc );
  }
  return rc;
}

/*
** Lower the locking level on file descriptor id to locktype.  locktype
** must be either NO_LOCK or SHARED_LOCK.
**
** If the locking level of the file descriptor is already at or below
** the requested locking level, this routine is a no-op.
**
** It is not possible for this routine to fail if the second argument
** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
** might return SQLITE_IOERR;
*/
int os2Unlock( sqlite3_file *id, int locktype ){
  int type;
  os2File *pFile = (os2File*)id;
  APIRET rc = SQLITE_OK;
  APIRET res = NO_ERROR;
  FILELOCK  LockArea,
            UnlockArea;
  memset(&LockArea, 0, sizeof(LockArea));
  memset(&UnlockArea, 0, sizeof(UnlockArea));
  assert( pFile!=0 );
  assert( locktype<=SHARED_LOCK );
  OSTRACE4( "UNLOCK %d to %d was %d\n", pFile->h, locktype, pFile->locktype );
  type = pFile->locktype;
  if( type>=EXCLUSIVE_LOCK ){
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = SHARED_FIRST;
    UnlockArea.lRange = SHARED_SIZE;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "UNLOCK %d exclusive lock res=%d\n", pFile->h, res );
    if( locktype==SHARED_LOCK && getReadLock(pFile) != NO_ERROR ){
      /* This should never happen.  We should always be able to
      ** reacquire the read lock */
      OSTRACE3( "UNLOCK %d to %d getReadLock() failed\n", pFile->h, locktype );
      rc = SQLITE_IOERR_UNLOCK;
    }
  }
  if( type>=RESERVED_LOCK ){
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = RESERVED_BYTE;
    UnlockArea.lRange = 1L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "UNLOCK %d reserved res=%d\n", pFile->h, res );
  }
  if( locktype==NO_LOCK && type>=SHARED_LOCK ){
    res = unlockReadLock(pFile);
    OSTRACE5( "UNLOCK %d is %d want %d res=%d\n", pFile->h, type, locktype, res );
  }
  if( type>=PENDING_LOCK ){
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = PENDING_BYTE;
    UnlockArea.lRange = 1L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "UNLOCK %d pending res=%d\n", pFile->h, res );
  }
  pFile->locktype = locktype;
  OSTRACE3( "UNLOCK %d now %d\n", pFile->h, pFile->locktype );
  return rc;
}

/*
** Control and query of the open file handle.
*/
static int os2FileControl(sqlite3_file *id, int op, void *pArg){
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = ((os2File*)id)->locktype;
      OSTRACE3( "FCNTL_LOCKSTATE %d lock=%d\n", ((os2File*)id)->h, ((os2File*)id)->locktype );
      return SQLITE_OK;
    }
  }
  return SQLITE_ERROR;
}

/*
** 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 its journal file) that the sector size will be the
** same for both.
*/
static int os2SectorSize(sqlite3_file *id){
  return SQLITE_DEFAULT_SECTOR_SIZE;
}

/*
** Return a vector of device characteristics.
*/
static int os2DeviceCharacteristics(sqlite3_file *id){
  return 0;
}

/*
** This vector defines all the methods that can operate on an
** sqlite3_file for os2.
*/
static const sqlite3_io_methods os2IoMethod = {
  1,                        /* iVersion */
  os2Close,
  os2Read,
  os2Write,
  os2Truncate,
  os2Sync,
  os2FileSize,
  os2Lock,
  os2Unlock,
  os2CheckReservedLock,
  os2FileControl,
  os2SectorSize,
  os2DeviceCharacteristics
};

/***************************************************************************
** Here ends the I/O methods that form the sqlite3_io_methods object.
**
** The next block of code implements the VFS methods.
****************************************************************************/

/*
** Open a file.
*/
static int os2Open(
  sqlite3_vfs *pVfs,            /* Not used */
  const char *zName,            /* Name of the file */
  sqlite3_file *id,             /* Write the SQLite file handle here */
  int flags,                    /* Open mode flags */
  int *pOutFlags                /* Status return flags */
){
  HFILE h;
  ULONG ulFileAttribute = 0;
  ULONG ulOpenFlags = 0;
  ULONG ulOpenMode = 0;
  os2File *pFile = (os2File*)id;
  APIRET rc = NO_ERROR;
  ULONG ulAction;

  memset(pFile, 0, sizeof(*pFile));

  OSTRACE2( "OPEN want %d\n", flags );

  //ulOpenMode = flags & SQLITE_OPEN_READWRITE ? OPEN_ACCESS_READWRITE : OPEN_ACCESS_READONLY;
  if( flags & SQLITE_OPEN_READWRITE ){
    ulOpenMode |= OPEN_ACCESS_READWRITE;
    OSTRACE1( "OPEN read/write\n" );
  }else{
    ulOpenMode |= OPEN_ACCESS_READONLY;
    OSTRACE1( "OPEN read only\n" );
  }

  //ulOpenFlags = flags & SQLITE_OPEN_CREATE ? OPEN_ACTION_CREATE_IF_NEW : OPEN_ACTION_FAIL_IF_NEW;
  if( flags & SQLITE_OPEN_CREATE ){
    ulOpenFlags |= OPEN_ACTION_OPEN_IF_EXISTS | OPEN_ACTION_CREATE_IF_NEW;
    OSTRACE1( "OPEN open new/create\n" );
  }else{
    ulOpenFlags |= OPEN_ACTION_OPEN_IF_EXISTS | OPEN_ACTION_FAIL_IF_NEW;
    OSTRACE1( "OPEN open existing\n" );
  }

  //ulOpenMode |= flags & SQLITE_OPEN_MAIN_DB ? OPEN_SHARE_DENYNONE : OPEN_SHARE_DENYWRITE;
  if( flags & SQLITE_OPEN_MAIN_DB ){
    ulOpenMode |= OPEN_SHARE_DENYNONE;
    OSTRACE1( "OPEN share read/write\n" );
  }else{
    ulOpenMode |= OPEN_SHARE_DENYWRITE;
    OSTRACE1( "OPEN share read only\n" );
  }

  if( flags & (SQLITE_OPEN_TEMP_DB | SQLITE_OPEN_TEMP_JOURNAL
               | SQLITE_OPEN_SUBJOURNAL) ){
    //ulFileAttribute = FILE_HIDDEN;  //for debugging, we want to make sure it is deleted
    ulFileAttribute = FILE_NORMAL;
    pFile->delOnClose = 1;
    pFile->pathToDel = (char*)malloc(sizeof(char) * pVfs->mxPathname);
    sqlite3OsFullPathname(pVfs, zName, pVfs->mxPathname, pFile->pathToDel);
    OSTRACE1( "OPEN hidden/delete on close file attributes\n" );
  }else{
    ulFileAttribute = FILE_ARCHIVED | FILE_NORMAL;
    pFile->delOnClose = 0;
    pFile->pathToDel = NULL;
    OSTRACE1( "OPEN normal file attribute\n" );
  }

  //ulOpenMode |= flags & (SQLITE_OPEN_MAIN_DB | SQLITE_OPEN_TEMP_DB) ?
  //                  OPEN_FLAGS_RANDOM : OPEN_FLAGS_SEQUENTIAL;
  if( flags & (SQLITE_OPEN_MAIN_DB | SQLITE_OPEN_TEMP_DB) ){
    ulOpenMode |= OPEN_FLAGS_RANDOM;
    OSTRACE1( "OPEN random access\n" );
  }else{
    ulOpenMode |= OPEN_FLAGS_SEQUENTIAL;
    OSTRACE1( "OPEN sequential access\n" );
  }
  ulOpenMode |= OPEN_FLAGS_FAIL_ON_ERROR;

  rc = DosOpen( (PSZ)zName,
                &h,
                &ulAction,
                0L,
                ulFileAttribute,
                ulOpenFlags,
                ulOpenMode,
                (PEAOP2)NULL );
  if( rc != NO_ERROR ){
    OSTRACE7( "OPEN Invalid handle rc=%d: zName=%s, ulAction=%#lx, ulAttr=%#lx, ulFlags=%#lx, ulMode=%#lx\n",
              rc, zName, ulAction, ulFileAttribute, ulOpenFlags, ulOpenMode );
    if( flags & SQLITE_OPEN_READWRITE ){
      OSTRACE2( "OPEN %d Invalid handle\n", ((flags | SQLITE_OPEN_READONLY) & ~SQLITE_OPEN_READWRITE) );
      return os2Open( 0, zName, id,
                      ((flags | SQLITE_OPEN_READONLY) & ~SQLITE_OPEN_READWRITE),
                      pOutFlags );
    }else{