/**
  * Checks if the storage has a given temp block.
  *
  * @param blockId the temp block ID
  * @return true if the block is contained, false otherwise
  */
 public synchronized boolean hasTempBlockMeta(long blockId) {
   for (StorageTier tier : mTiers) {
     for (StorageDir dir : tier.getStorageDirs()) {
       if (dir.hasTempBlockMeta(blockId)) {
         return true;
       }
     }
   }
   return false;
 }
 /**
  * Gets the metadata of a temp block.
  *
  * @param blockId the ID of the temp block
  * @return metadata of the block or null
  * @throws NotFoundException when blockId can not be found
  */
 public synchronized TempBlockMeta getTempBlockMeta(long blockId) throws NotFoundException {
   for (StorageTier tier : mTiers) {
     for (StorageDir dir : tier.getStorageDirs()) {
       if (dir.hasTempBlockMeta(blockId)) {
         return dir.getTempBlockMeta(blockId);
       }
     }
   }
   throw new NotFoundException(
       "Failed to get TempBlockMeta: temp blockId " + blockId + " not found");
 }