[HDFS-13246] FileInputStream redundant closes in readReplicasFromCache

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.2.0
• Fix Version/s: 3.1.0
• Component/s: datanode
• Hadoop Flags: Reviewed
• Assignee: liaoyuxiangqin
• Reporter: liaoyuxiangqin
• Created: 08/Mar/18 06:20
• Updated: 19/Mar/18 18:31
• Resolved: 15/Mar/18 05:00

Description

When i read the readReplicasFromCache() of BlockPoolSlice class in datanode, I found the following code closes fileinputstream redundant, I think  IOUtils.closeStream(inputStream) in finally code block could guarantee close the inputStream correctly, So the

inputStream.close() can remove. Thanks.

 

BlockPoolSlice.java

FileInputStream inputStream = null;
    try {
      inputStream = fileIoProvider.getFileInputStream(volume, replicaFile);
      BlockListAsLongs blocksList =
          BlockListAsLongs.readFrom(inputStream, maxDataLength);
      if (blocksList == null) {
        return false;
      }

      for (BlockReportReplica replica : blocksList) {
        switch (replica.getState()) {
        case FINALIZED:
          addReplicaToReplicasMap(replica, tmpReplicaMap, lazyWriteReplicaMap, true);
          break;
        case RUR:
        case RBW:
        case RWR:
          addReplicaToReplicasMap(replica, tmpReplicaMap, lazyWriteReplicaMap, false);
          break;
        default:
          break;
        }
      }
      inputStream.close();

      // Now it is safe to add the replica into volumeMap
      // In case of any exception during parsing this cache file, fall back
      // to scan all the files on disk.
      for (Iterator<ReplicaInfo> iter =
          tmpReplicaMap.replicas(bpid).iterator(); iter.hasNext(); ) {
        ReplicaInfo info = iter.next();
        // We use a lightweight GSet to store replicaInfo, we need to remove
        // it from one GSet before adding to another.
        iter.remove();
        volumeMap.add(bpid, info);
      }
      LOG.info("Successfully read replica from cache file : "
          + replicaFile.getPath());
      return true;
    } catch (Exception e) {
      // Any exception we need to revert back to read from disk
      // Log the error and return false
      LOG.info("Exception occurred while reading the replicas cache file: "
          + replicaFile.getPath(), e );
      return false;
    }
    finally {
      if (!fileIoProvider.delete(volume, replicaFile)) {
        LOG.info("Failed to delete replica cache file: " +
            replicaFile.getPath());
      }

      // close the inputStream
      IOUtils.closeStream(inputStream);
    }