/**
* Aborts a temp block.
*
* @param sessionId the id of session
* @param blockId the id of block
* @throws BlockDoesNotExistException if block id can not be found in temporary blocks
* @throws BlockAlreadyExistsException if block id already exists in committed blocks
* @throws InvalidWorkerStateException if block id is not owned by session id
* @throws IOException if I/O errors occur when deleting the block file
*/
private void abortBlockInternal(long sessionId, long blockId)
throws BlockDoesNotExistException, BlockAlreadyExistsException, InvalidWorkerStateException,
IOException {
long lockId = mLockManager.lockBlock(sessionId, blockId, BlockLockType.WRITE);
try {
String path;
TempBlockMeta tempBlockMeta;
mMetadataReadLock.lock();
try {
checkTempBlockOwnedBySession(sessionId, blockId);
tempBlockMeta = mMetaManager.getTempBlockMeta(blockId);
path = tempBlockMeta.getPath();
} finally {
mMetadataReadLock.unlock();
}
// Heavy IO is guarded by block lock but not metadata lock. This may throw IOException.
Files.delete(Paths.get(path));
mMetadataWriteLock.lock();
try {
mMetaManager.abortTempBlockMeta(tempBlockMeta);
} catch (BlockDoesNotExistException e) {
throw Throwables.propagate(e); // We shall never reach here
} finally {
mMetadataWriteLock.unlock();
}
} finally {
mLockManager.unlockBlock(lockId);
}
}
/**
* Checks if block id is a temporary block and owned by session id. This method must be enclosed
* by {@link #mMetadataLock}.
*
* @param sessionId the id of session
* @param blockId the id of block
* @throws BlockDoesNotExistException if block id can not be found in temporary blocks
* @throws BlockAlreadyExistsException if block id already exists in committed blocks
* @throws InvalidWorkerStateException if block id is not owned by session id
*/
private void checkTempBlockOwnedBySession(long sessionId, long blockId)
throws BlockDoesNotExistException, BlockAlreadyExistsException, InvalidWorkerStateException {
if (mMetaManager.hasBlockMeta(blockId)) {
throw new BlockAlreadyExistsException(ExceptionMessage.TEMP_BLOCK_ID_COMMITTED, blockId);
}
TempBlockMeta tempBlockMeta = mMetaManager.getTempBlockMeta(blockId);
long ownerSessionId = tempBlockMeta.getSessionId();
if (ownerSessionId != sessionId) {
throw new InvalidWorkerStateException(
ExceptionMessage.BLOCK_ID_FOR_DIFFERENT_SESSION, blockId, ownerSessionId, sessionId);
}
}
@Override
public BlockWriter getBlockWriter(long sessionId, long blockId)
throws BlockDoesNotExistException, IOException {
// NOTE: a temp block is supposed to only be visible by its own writer, unnecessary to acquire
// block lock here since no sharing
// TODO(bin): Handle the case where multiple writers compete for the same block.
mMetadataReadLock.lock();
try {
TempBlockMeta tempBlockMeta = mMetaManager.getTempBlockMeta(blockId);
return new LocalFileBlockWriter(tempBlockMeta.getPath());
} finally {
mMetadataReadLock.unlock();
}
}
/**
* Commits a temp block.
*
* @param sessionId the id of session
* @param blockId the id of block
* @return destination location to move the block
* @throws BlockDoesNotExistException if block id can not be found in temporary blocks
* @throws BlockAlreadyExistsException if block id already exists in committed blocks
* @throws InvalidWorkerStateException if block id is not owned by session id
* @throws IOException if I/O errors occur when deleting the block file
*/
private BlockStoreLocation commitBlockInternal(long sessionId, long blockId)
throws BlockAlreadyExistsException, InvalidWorkerStateException, BlockDoesNotExistException,
IOException {
long lockId = mLockManager.lockBlock(sessionId, blockId, BlockLockType.WRITE);
try {
// When committing TempBlockMeta, the final BlockMeta calculates the block size according to
// the actual file size of this TempBlockMeta. Therefore, commitTempBlockMeta must happen
// after moving actual block file to its committed path.
BlockStoreLocation loc;
String srcPath;
String dstPath;
TempBlockMeta tempBlockMeta;
mMetadataReadLock.lock();
try {
checkTempBlockOwnedBySession(sessionId, blockId);
tempBlockMeta = mMetaManager.getTempBlockMeta(blockId);
srcPath = tempBlockMeta.getPath();
dstPath = tempBlockMeta.getCommitPath();
loc = tempBlockMeta.getBlockLocation();
} finally {
mMetadataReadLock.unlock();
}
// Heavy IO is guarded by block lock but not metadata lock. This may throw IOException.
FileUtils.move(srcPath, dstPath);
mMetadataWriteLock.lock();
try {
mMetaManager.commitTempBlockMeta(tempBlockMeta);
} catch (BlockAlreadyExistsException e) {
throw Throwables.propagate(e); // we shall never reach here
} catch (BlockDoesNotExistException e) {
throw Throwables.propagate(e); // we shall never reach here
} catch (WorkerOutOfSpaceException e) {
throw Throwables.propagate(e); // we shall never reach here
} finally {
mMetadataWriteLock.unlock();
}
return loc;
} finally {
mLockManager.unlockBlock(lockId);
}
}
/**
* Increases the temp block size only if this temp block's parent dir has enough available space.
*
* @param blockId block Id
* @param additionalBytes additional bytes to request for this block
* @return a pair of boolean and {@link BlockStoreLocation}. The boolean indicates if the
* operation succeeds and the {@link BlockStoreLocation} denotes where to free more space if
* it fails.
* @throws BlockDoesNotExistException if this block is not found
*/
private Pair<Boolean, BlockStoreLocation> requestSpaceInternal(long blockId, long additionalBytes)
throws BlockDoesNotExistException {
// NOTE: a temp block is supposed to be visible for its own writer, unnecessary to acquire
// block lock here since no sharing
mMetadataWriteLock.lock();
try {
TempBlockMeta tempBlockMeta = mMetaManager.getTempBlockMeta(blockId);
if (tempBlockMeta.getParentDir().getAvailableBytes() < additionalBytes) {
return new Pair<Boolean, BlockStoreLocation>(false, tempBlockMeta.getBlockLocation());
}
// Increase the size of this temp block
try {
mMetaManager.resizeTempBlockMeta(
tempBlockMeta, tempBlockMeta.getBlockSize() + additionalBytes);
} catch (InvalidWorkerStateException e) {
throw Throwables.propagate(e); // we shall never reach here
}
return new Pair<Boolean, BlockStoreLocation>(true, null);
} finally {
mMetadataWriteLock.unlock();
}
}