001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hdfs.server.datanode.fsdataset;
019
020import java.io.Closeable;
021import java.io.FileOutputStream;
022import java.io.OutputStream;
023import java.io.IOException;
024
025import org.apache.hadoop.io.IOUtils;
026import org.apache.hadoop.util.DataChecksum;
027
028/**
029 * Contains the output streams for the data and checksum of a replica.
030 */
031public class ReplicaOutputStreams implements Closeable {
032  private final OutputStream dataOut;
033  private final OutputStream checksumOut;
034  private final DataChecksum checksum;
035  private final boolean isTransientStorage;
036
037  /**
038   * Create an object with a data output stream, a checksum output stream
039   * and a checksum.
040   */
041  public ReplicaOutputStreams(OutputStream dataOut, OutputStream checksumOut,
042      DataChecksum checksum, boolean isTransientStorage) {
043    this.dataOut = dataOut;
044    this.checksumOut = checksumOut;
045    this.checksum = checksum;
046    this.isTransientStorage = isTransientStorage;
047  }
048
049  /** @return the data output stream. */
050  public OutputStream getDataOut() {
051    return dataOut;
052  }
053
054  /** @return the checksum output stream. */
055  public OutputStream getChecksumOut() {
056    return checksumOut;
057  }
058
059  /** @return the checksum. */
060  public DataChecksum getChecksum() {
061    return checksum;
062  }
063
064  /** @return is writing to a transient storage? */
065  public boolean isTransientStorage() {
066    return isTransientStorage;
067  }
068
069  @Override
070  public void close() {
071    IOUtils.closeStream(dataOut);
072    IOUtils.closeStream(checksumOut);
073  }
074
075  /**
076   * Sync the data stream if it supports it.
077   */
078  public void syncDataOut() throws IOException {
079    if (dataOut instanceof FileOutputStream) {
080      ((FileOutputStream)dataOut).getChannel().force(true);
081    }
082  }
083  
084  /**
085   * Sync the checksum stream if it supports it.
086   */
087  public void syncChecksumOut() throws IOException {
088    if (checksumOut instanceof FileOutputStream) {
089      ((FileOutputStream)checksumOut).getChannel().force(true);
090    }
091  }
092
093}