/**
* Initialize meta data for existing blocks in this StorageDir
*
* <p>Only paths satisfying the contract defined in {@link BlockMetaBase#commitPath} are legal,
* should be in format like {dir}/{blockId}. other paths will be deleted.
*
* @throws IOException when meta data of existing committed blocks can not be loaded
*/
private void initializeMeta() throws IOException {
File dir = new File(mDirPath);
File[] paths = dir.listFiles();
if (paths == null) {
return;
}
for (File path : paths) {
if (!path.isFile()) {
LOG.error("{} in StorageDir is not a file", path.getAbsolutePath());
try {
FileUtils.deleteDirectory(path);
} catch (IOException ioe) {
LOG.error("can not delete directory {}: {}", path.getAbsolutePath(), ioe);
}
} else {
try {
long blockId = Long.valueOf(path.getName());
addBlockMeta(new BlockMeta(blockId, path.length(), this));
} catch (NumberFormatException nfe) {
LOG.error(
"filename of {} in StorageDir can not be parsed into long", path.getAbsolutePath());
if (path.delete()) {
LOG.warn("file {} has been deleted", path.getAbsolutePath());
} else {
LOG.error("can not delete file {}", path.getAbsolutePath());
}
} catch (IOException ioe) {
LOG.error("can not add block meta of file {}: {}", path.getAbsolutePath(), ioe);
throw ioe;
}
}
}
}
/**
* Commits a temp block.
*
* @param tempBlockMeta the meta data of the temp block to commit
* @throws OutOfSpaceException when no more space left to hold the block
* @throws AlreadyExistsException when the block already exists in committed blocks
* @throws NotFoundException when temp block can not be found
*/
public synchronized void commitTempBlockMeta(TempBlockMeta tempBlockMeta)
throws OutOfSpaceException, AlreadyExistsException, NotFoundException {
BlockMeta block = new BlockMeta(Preconditions.checkNotNull(tempBlockMeta));
StorageDir dir = tempBlockMeta.getParentDir();
dir.removeTempBlockMeta(tempBlockMeta);
dir.addBlockMeta(block);
}
/**
* Moves the metadata of an existing block to another location or throws IOExceptions.
*
* @param blockMeta the meta data of the block to move
* @param newLocation new location of the block
* @return the new block metadata if success, absent otherwise
* @throws IllegalArgumentException when the newLocation is not in the tiered storage
* @throws NotFoundException when the block to move is not found
* @throws AlreadyExistsException when the block to move already exists in the destination
* @throws OutOfSpaceException when destination have no extra space to hold the block to move
*/
public synchronized BlockMeta moveBlockMeta(BlockMeta blockMeta, BlockStoreLocation newLocation)
throws NotFoundException, AlreadyExistsException, OutOfSpaceException {
// If existing location belongs to the target location, simply return the current block meta.
BlockStoreLocation oldLocation = blockMeta.getBlockLocation();
if (oldLocation.belongTo(newLocation)) {
LOG.info("moveBlockMeta: moving {} to {} is a noop", oldLocation, newLocation);
return blockMeta;
}
long blockSize = blockMeta.getBlockSize();
int newTierAlias = newLocation.tierAlias();
StorageTier newTier = getTier(newTierAlias);
StorageDir newDir = null;
if (newLocation.equals(BlockStoreLocation.anyDirInTier(newTierAlias))) {
for (StorageDir dir : newTier.getStorageDirs()) {
if (dir.getAvailableBytes() >= blockSize) {
newDir = dir;
break;
}
}
} else {
StorageDir dir = newTier.getDir(newLocation.dir());
if (dir.getAvailableBytes() >= blockSize) {
newDir = dir;
}
}
if (newDir == null) {
throw new OutOfSpaceException(
"Failed to move BlockMeta: newLocation "
+ newLocation
+ " does not have enough space for "
+ blockSize
+ " bytes");
}
StorageDir oldDir = blockMeta.getParentDir();
oldDir.removeBlockMeta(blockMeta);
BlockMeta newBlockMeta = new BlockMeta(blockMeta.getBlockId(), blockSize, newDir);
newDir.addBlockMeta(newBlockMeta);
return newBlockMeta;
}