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.namenode.snapshot;
019    
020    import org.apache.hadoop.hdfs.server.namenode.INode;
021    import org.apache.hadoop.hdfs.server.namenode.INode.BlocksMapUpdateInfo;
022    import org.apache.hadoop.hdfs.server.namenode.INodeFile;
023    import org.apache.hadoop.hdfs.server.namenode.INodeFileAttributes;
024    import org.apache.hadoop.hdfs.server.namenode.Quota;
025    
026    import java.util.List;
027    
028    /**
029     * The difference of an {@link INodeFile} between two snapshots.
030     */
031    public class FileDiff extends
032        AbstractINodeDiff<INodeFile, INodeFileAttributes, FileDiff> {
033    
034      /** The file size at snapshot creation time. */
035      private final long fileSize;
036    
037      FileDiff(int snapshotId, INodeFile file) {
038        super(snapshotId, null, null);
039        fileSize = file.computeFileSize();
040      }
041    
042      /** Constructor used by FSImage loading */
043      FileDiff(int snapshotId, INodeFileAttributes snapshotINode,
044          FileDiff posteriorDiff, long fileSize) {
045        super(snapshotId, snapshotINode, posteriorDiff);
046        this.fileSize = fileSize;
047      }
048    
049      /** @return the file size in the snapshot. */
050      public long getFileSize() {
051        return fileSize;
052      }
053      
054      @Override
055      Quota.Counts combinePosteriorAndCollectBlocks(INodeFile currentINode,
056          FileDiff posterior, BlocksMapUpdateInfo collectedBlocks,
057          final List<INode> removedINodes) {
058        return currentINode.getFileWithSnapshotFeature()
059            .updateQuotaAndCollectBlocks(currentINode, posterior, collectedBlocks,
060                removedINodes);
061      }
062      
063      @Override
064      public String toString() {
065        return super.toString() + " fileSize=" + fileSize + ", rep="
066            + (snapshotINode == null? "?": snapshotINode.getFileReplication());
067      }
068    
069      @Override
070      Quota.Counts destroyDiffAndCollectBlocks(INodeFile currentINode,
071          BlocksMapUpdateInfo collectedBlocks, final List<INode> removedINodes) {
072        return currentINode.getFileWithSnapshotFeature()
073            .updateQuotaAndCollectBlocks(currentINode, this, collectedBlocks,
074                removedINodes);
075      }
076    }