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.server.common.HdfsServerConstants.ReplicaState;
023    import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
024    import org.apache.hadoop.hdfs.server.protocol.ReplicaRecoveryInfo;
025    
026    /**
027     * This class represents replicas that are under block recovery
028     * It has a recovery id that is equal to the generation stamp 
029     * that the replica will be bumped to after recovery
030     * The recovery id is used to handle multiple concurrent block recoveries.
031     * A recovery with higher recovery id preempts recoveries with a lower id.
032     *
033     */
034    public class ReplicaUnderRecovery extends ReplicaInfo {
035      private ReplicaInfo original; // the original replica that needs to be recovered
036      private long recoveryId; // recovery id; it is also the generation stamp 
037                               // that the replica will be bumped to after recovery
038    
039      public ReplicaUnderRecovery(ReplicaInfo replica, long recoveryId) {
040        super(replica.getBlockId(), replica.getNumBytes(), replica.getGenerationStamp(),
041            replica.getVolume(), replica.getDir());
042        if ( replica.getState() != ReplicaState.FINALIZED &&
043             replica.getState() != ReplicaState.RBW &&
044             replica.getState() != ReplicaState.RWR ) {
045          throw new IllegalArgumentException("Cannot recover replica: " + replica);
046        }
047        this.original = replica;
048        this.recoveryId = recoveryId;
049      }
050    
051      /**
052       * Copy constructor.
053       * @param from
054       */
055      public ReplicaUnderRecovery(ReplicaUnderRecovery from) {
056        super(from);
057        this.original = from.getOriginalReplica();
058        this.recoveryId = from.getRecoveryID();
059      }
060    
061      /** 
062       * Get the recovery id
063       * @return the generation stamp that the replica will be bumped to 
064       */
065      public long getRecoveryID() {
066        return recoveryId;
067      }
068    
069      /** 
070       * Set the recovery id
071       * @param recoveryId the new recoveryId
072       */
073      public void setRecoveryID(long recoveryId) {
074        if (recoveryId > this.recoveryId) {
075          this.recoveryId = recoveryId;
076        } else {
077          throw new IllegalArgumentException("The new rcovery id: " + recoveryId
078              + " must be greater than the current one: " + this.recoveryId);
079        }
080      }
081    
082      /**
083       * Get the original replica that's under recovery
084       * @return the original replica under recovery
085       */
086      public ReplicaInfo getOriginalReplica() {
087        return original;
088      }
089    
090      @Override //ReplicaInfo
091      public boolean isUnlinked() {
092        return original.isUnlinked();
093      }
094    
095      @Override //ReplicaInfo
096      public void setUnlinked() {
097        original.setUnlinked();
098      }
099      
100      @Override //ReplicaInfo
101      public ReplicaState getState() {
102        return ReplicaState.RUR;
103      }
104      
105      @Override
106      public long getVisibleLength() {
107        return original.getVisibleLength();
108      }
109    
110      @Override
111      public long getBytesOnDisk() {
112        return original.getBytesOnDisk();
113      }
114    
115      @Override  //org.apache.hadoop.hdfs.protocol.Block
116      public void setBlockId(long blockId) {
117        super.setBlockId(blockId);
118        original.setBlockId(blockId);
119      }
120    
121      @Override //org.apache.hadoop.hdfs.protocol.Block
122      public void setGenerationStamp(long gs) {
123        super.setGenerationStamp(gs);
124        original.setGenerationStamp(gs);
125      }
126      
127      @Override //org.apache.hadoop.hdfs.protocol.Block
128      public void setNumBytes(long numBytes) {
129        super.setNumBytes(numBytes);
130        original.setNumBytes(numBytes);
131      }
132      
133      @Override //ReplicaInfo
134      public void setDir(File dir) {
135        super.setDir(dir);
136        original.setDir(dir);
137      }
138      
139      @Override //ReplicaInfo
140      void setVolume(FsVolumeSpi vol) {
141        super.setVolume(vol);
142        original.setVolume(vol);
143      }
144      
145      @Override  // Object
146      public boolean equals(Object o) {
147        return super.equals(o);
148      }
149      
150      @Override  // Object
151      public int hashCode() {
152        return super.hashCode();
153      }
154    
155      @Override
156      public String toString() {
157        return super.toString()
158            + "\n  recoveryId=" + recoveryId
159            + "\n  original=" + original;
160      }
161    
162      public ReplicaRecoveryInfo createInfo() {
163        return new ReplicaRecoveryInfo(original.getBlockId(), 
164            original.getBytesOnDisk(), original.getGenerationStamp(),
165            original.getState()); 
166      }
167    }