/**
* 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;
}
/**
* Gets the amount of available space of given location in bytes. Master queries the total number
* of bytes available on each tier of the worker, and Evictor/Allocator often cares about the
* bytes at a {@link StorageDir}.
*
* @param location location the check available bytes
* @return available bytes
* @throws IllegalArgumentException when location does not belong to tiered storage
*/
public synchronized long getAvailableBytes(BlockStoreLocation location) {
long spaceAvailable = 0;
if (location.equals(BlockStoreLocation.anyTier())) {
for (StorageTier tier : mTiers) {
spaceAvailable += tier.getAvailableBytes();
}
return spaceAvailable;
}
int tierAlias = location.tierAlias();
StorageTier tier = getTier(tierAlias);
// TODO: This should probably be max of the capacity bytes in the dirs?
if (location.equals(BlockStoreLocation.anyDirInTier(tierAlias))) {
return tier.getAvailableBytes();
}
int dirIndex = location.dir();
StorageDir dir = tier.getDir(dirIndex);
return dir.getAvailableBytes();
}