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     */
018    package org.apache.hadoop.hdfs.server.datanode;
019    
020    import java.io.File;
021    
022    import org.apache.hadoop.hdfs.protocol.Block;
023    import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
024    import 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 It will become outdated if its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     */
035    public 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 where to copy 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    }