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;
019
020import java.io.File;
021
022import org.apache.hadoop.hdfs.protocol.Block;
023import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
024import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
025
026/**
027 * This class represents a replica that is waiting to be recovered.
028 * After a datanode restart, any replica in "rbw" directory is loaded
029 * as a replica waiting to be recovered.
030 * A replica waiting to be recovered does not provision read nor
031 * participates in any pipeline recovery. It will become outdated if its
032 * client continues to write or be recovered as a result of
033 * lease recovery.
034 */
035public class ReplicaWaitingToBeRecovered extends ReplicaInfo {
036  private boolean unlinked;      // copy-on-write done for block
037
038  /**
039   * Constructor
040   * @param blockId block id
041   * @param len replica length
042   * @param genStamp replica generation stamp
043   * @param vol volume where replica is located
044   * @param dir directory path where block and meta files are located
045   */
046  public ReplicaWaitingToBeRecovered(long blockId, long len, long genStamp,
047      FsVolumeSpi vol, File dir) {
048    super(blockId, len, genStamp, vol, dir);
049  }
050  
051  /**
052   * Constructor
053   * @param block a block
054   * @param vol volume where replica is located
055   * @param dir directory path where block and meta files are located
056   */
057  public ReplicaWaitingToBeRecovered(Block block, FsVolumeSpi vol, File dir) {
058    super(block, vol, dir);
059  }
060  
061  /**
062   * Copy constructor.
063   * @param from
064   */
065  public ReplicaWaitingToBeRecovered(ReplicaWaitingToBeRecovered from) {
066    super(from);
067    this.unlinked = from.isUnlinked();
068  }
069
070  @Override //ReplicaInfo
071  public ReplicaState getState() {
072    return ReplicaState.RWR;
073  }
074  
075  @Override //ReplicaInfo
076  public boolean isUnlinked() {
077    return unlinked;
078  }
079
080  @Override //ReplicaInfo
081  public void setUnlinked() {
082    unlinked = true;
083  }
084  
085  @Override //ReplicaInfo
086  public long getVisibleLength() {
087    return -1;  //no bytes are visible
088  }
089  
090  @Override
091  public long getBytesOnDisk() {
092    return getNumBytes();
093  }
094
095  @Override  // Object
096  public boolean equals(Object o) {
097    return super.equals(o);
098  }
099  
100  @Override  // Object
101  public int hashCode() {
102    return super.hashCode();
103  }
104
105  @Override
106  public String toString() {
107    return super.toString()
108        + "\n  unlinked=" + unlinked;
109  }
110}