How to use

getChecksumOut

method

in

org.apache.hadoop.hdfs.server.datanode.fsdataset.ReplicaOutputStreams

/**
 * Sets the offset in the meta file so that the
 * last checksum will be overwritten.
 */
@Override // FsDatasetSpi
public void adjustCrcChannelPosition(ExtendedBlock b, ReplicaOutputStreams streams, 
  int checksumSize) throws IOException {
 FileOutputStream file = (FileOutputStream)streams.getChecksumOut();
 FileChannel channel = file.getChannel();
 long oldPos = channel.position();
 long newPos = oldPos - checksumSize;
 if (LOG.isDebugEnabled()) {
  LOG.debug("Changing meta file offset of block " + b + " from " +
    oldPos + " to " + newPos);
 }
 channel.position(newPos);
}

streams.getChecksumOut(), DFSUtilClient.getSmallBufferSize(
datanode.getConf())));

/**
 * Sets the offset in the meta file so that the
 * last checksum will be overwritten.
 */
@Override // FsDatasetSpi
public void adjustCrcChannelPosition(ExtendedBlock b, ReplicaOutputStreams streams, 
  int checksumSize) throws IOException {
 FileOutputStream file = (FileOutputStream)streams.getChecksumOut();
 FileChannel channel = file.getChannel();
 long oldPos = channel.position();
 long newPos = oldPos - checksumSize;
 if (LOG.isDebugEnabled()) {
  LOG.debug("Changing meta file offset of block " + b + " from " +
    oldPos + " to " + newPos);
 }
 channel.position(newPos);
}

/**
 * Sets the offset in the meta file so that the
 * last checksum will be overwritten.
 */
@Override // FsDatasetSpi
public void adjustCrcChannelPosition(ExtendedBlock b, ReplicaOutputStreams streams, 
  int checksumSize) throws IOException {
 FileOutputStream file = (FileOutputStream)streams.getChecksumOut();
 FileChannel channel = file.getChannel();
 long oldPos = channel.position();
 long newPos = oldPos - checksumSize;
 if (LOG.isDebugEnabled()) {
  LOG.debug("Changing meta file offset of block " + b + " from " +
    oldPos + " to " + newPos);
 }
 channel.position(newPos);
}

streams.getChecksumOut(), HdfsConstants.SMALL_BUFFER_SIZE));

streams = replicaInfo.createStreams(true,
  DataChecksum.newDataChecksum(DataChecksum.Type.CRC32, 512));
streams.getChecksumOut().write('a');
dn.data.initReplicaRecovery(new RecoveringBlock(block, null, RECOVERY_ID+1));
try {

streams.getChecksumOut(), HdfsConstants.SMALL_BUFFER_SIZE));