/**
* Lock the blocks. The blocks are locked in ascending block id order to avoid deadlocks.
*
* @param isWrite if true, the block should be locked for writing
*/
public void lock() throws SQLException {
if (_isNonLocking) return;
if (_isLocked) {
throw new IllegalStateException(L.l("blocks are already locked"));
}
_isLocked = true;
if (_thread != Thread.currentThread()) throw new IllegalStateException();
int len = _tableIterators.length;
for (int i = 0; i < len; i++) {
Block bestBlock = null;
long bestId = Long.MAX_VALUE;
loop:
for (int j = 0; j < len; j++) {
TableIterator iter = _tableIterators[j];
if (iter == null) continue;
Block block = iter.getBlock();
if (block == null) continue;
long id = block.getBlockId();
if (bestId <= id) continue;
for (int k = 0; k < i; k++) {
if (_blockLocks[k] == block) continue loop;
}
bestId = id;
bestBlock = block;
}
try {
if (bestBlock == null) {
} else if (_isWrite) {
bestBlock.getWriteLock().tryLock(_xa.getTimeout(), TimeUnit.MILLISECONDS);
} else {
bestBlock.getReadLock().tryLock(_xa.getTimeout(), TimeUnit.MILLISECONDS);
}
} catch (Exception e) {
throw new IllegalStateException(e);
}
// assignment must be after obtaining lock because the unlock
// requires a lock
_blockLocks[i] = bestBlock;
}
}
/** Returns the following block. */
public boolean nextBlock() throws IOException {
byte[] buffer = _buffer;
Block block = _block;
_block = null;
_buffer = null;
if (block != null) {
block.free();
}
_blockId = _table.firstRowBlock(_blockId + Table.BLOCK_SIZE);
if (_blockId < 0) {
return false;
}
block = _xa.readBlock(_table, _blockId);
buffer = block.getBuffer();
_block = block;
_buffer = buffer;
_rowOffset = 0;
return true;
}
public void close() throws SQLException {
Thread thread = _thread;
_thread = null;
unlock();
if (thread != null && thread != Thread.currentThread()) {
throw new IllegalStateException();
}
DbTransaction xa = _xa;
_xa = null;
// db/0a10
if (xa != null && xa.isAutoCommit()) xa.commit();
}
/**
* Unlock the blocks. The blocks are unlocked in descending order.
*
* @param isWrite if true, the block should be unlocked for writing
*/
public void unlock() throws SQLException {
if (_isNonLocking) return;
if (!_isLocked) {
return;
}
_isLocked = false;
if (_thread != null && _thread != Thread.currentThread())
throw new IllegalStateException(
String.valueOf(_thread) + " current " + Thread.currentThread());
int len = _blockLocks.length;
// need to unlock first since the writeData/commit will wait for
// write locks to clear before committing
for (int i = len - 1; i >= 0; i--) {
Block block = _blockLocks[i];
if (block == null) {
} else if (_isWrite) {
block.getWriteLock().unlock();
} else {
block.getReadLock().unlock();
}
}
try {
_xa.writeData();
} finally {
for (int i = len - 1; i >= 0; i--) {
Block block = _blockLocks[i];
_blockLocks[i] = null;
if (block == null) {
} else if (_isWrite) {
try {
block.commit();
} catch (Exception e) {
log.log(Level.FINE, e.toString(), e);
}
}
}
}
}
/** Sets the next row. */
public void setRow(long rowAddr) throws IOException {
long blockId = _table.addressToBlockId(rowAddr);
if (blockId != _blockId) {
_blockId = blockId;
Block block = _block;
_block = null;
_buffer = null;
if (block != null) {
block.free();
}
_block = _xa.readBlock(_table, _blockId);
_buffer = _block.getBuffer();
}
_rowOffset = (int) (rowAddr & BlockStore.BLOCK_OFFSET_MASK);
}
public void setDirty() throws SQLException {
_xa.addUpdateBlock(_block);
_block.setDirty(_rowOffset, _rowOffset + _rowLength);
}
