Java Code Examples for org.apache.hadoop.fs.FSOutputSummer

The following examples show how to use org.apache.hadoop.fs.FSOutputSummer. These examples are extracted from open source projects. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source Project: RDFS   Source File: BlockXCodingMerger.java    License: Apache License 2.0 4 votes vote down vote up
@Override
void writePacket(DataTransferPacket packet) throws IOException {
	
	if (!writtenHeader) {
		writeChecksumHeader(checksum);
		writtenHeader = true;
	}
	
    boolean forceSync = packet.isForceSync();
    int dataLength = packet.dataLength;
    
    if (dataLength <= 0) {
      LOG.warn("NTar: writePacket: Receiving empty packet:" + 
    		  packet + " for block " + block);
    } else {
      dataLength = (int) Math.min(dataLength, this.length - this.writtenLength);
      setBlockPosition(offsetInBlock);  // adjust file position
      offsetInBlock += dataLength;
      this.writtenLength += dataLength;

      int checksumLength = (dataLength + bytesPerChecksum -1)/bytesPerChecksum 
    		  * checksumSize;
     
      byte[] pktBuf = new byte[checksumLength + dataLength];
      Arrays.fill(pktBuf, (byte)0);
      System.arraycopy(packet.buffer, 0, pktBuf, 
    		  checksumLength, dataLength);
      ChecksumUtil.updateChunkChecksum(pktBuf, 0,
    		  checksumLength, dataLength, checksum);
      
      try {
        if (!finalized) {
          long writeStartTime = System.currentTimeMillis();
          //finally write to the disk :
          out.write(pktBuf, checksumLength, dataLength);

          // If this is a partial chunk, then verify that this is the only
          // chunk in the packet. Calculate new crc for this chunk.
          if (partialCrc != null) {
            if (dataLength > bytesPerChecksum) {
              throw new IOException("Got wrong length during mergeBlock(" + 
                                    block + ") from " + childAddrs + " " +
                                    "A packet can have only one partial chunk."+
                                    " len = " + dataLength + 
                                    " bytesPerChecksum " + bytesPerChecksum);
            }
            partialCrc.update(pktBuf, checksumLength, dataLength);
            byte[] buf = FSOutputSummer.convertToByteStream(partialCrc, checksumSize);
            checksumOut.write(buf);
            LOG.debug("Writing out partial crc for data len " + dataLength);
            partialCrc = null;
          } else {
            checksumOut.write(pktBuf, 0, checksumLength);
          }
          datanode.myMetrics.bytesWritten.inc(dataLength);

          flush(forceSync);

          this.replicaBeingWritten.setBytesOnDisk(offsetInBlock);
          // Record time taken to write packet
          long writePacketDuration = System.currentTimeMillis() - writeStartTime;
          datanode.myMetrics.writePacketLatency.inc(writePacketDuration);
        }
      } catch (ClosedByInterruptException cix) {
        LOG.warn( "NTar: Thread interrupted when flushing bytes to disk."
        		+ "Might cause inconsistent sates", cix);
        throw cix;
      } catch (InterruptedIOException iix) {
        LOG.warn(
            "NTar: InterruptedIOException when flushing bytes to disk."
        		+ "Might cause inconsistent sates", iix);
        throw iix;
      } catch (IOException iex) {
        datanode.checkDiskError(iex);
        throw iex;
      }
    }
  }