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.hbase.io.hfile;
019
020import org.apache.hadoop.fs.Path;
021import org.apache.hadoop.hbase.io.HeapSize;
022import org.apache.hadoop.hbase.util.ClassSize;
023import org.apache.yetus.audience.InterfaceAudience;
024
025/**
026 * Cache Key for use with implementations of {@link BlockCache}
027 */
028@InterfaceAudience.Private
029public class BlockCacheKey implements HeapSize, java.io.Serializable {
030  private static final long serialVersionUID = -5199992013113130534L;
031  private final String hfileName;
032  private final long offset;
033  private BlockType blockType;
034  private final boolean isPrimaryReplicaBlock;
035  private Path filePath;
036
037  /**
038   * Construct a new BlockCacheKey
039   * @param hfileName The name of the HFile this block belongs to.
040   * @param offset    Offset of the block into the file
041   */
042  public BlockCacheKey(String hfileName, long offset) {
043    this(hfileName, offset, true, BlockType.DATA);
044  }
045
046  public BlockCacheKey(String hfileName, long offset, boolean isPrimaryReplica,
047    BlockType blockType) {
048    this.isPrimaryReplicaBlock = isPrimaryReplica;
049    this.hfileName = hfileName;
050    this.offset = offset;
051    this.blockType = blockType;
052  }
053
054  public BlockCacheKey(Path hfilePath, long offset, boolean isPrimaryReplica, BlockType blockType) {
055    this.filePath = hfilePath;
056    this.isPrimaryReplicaBlock = isPrimaryReplica;
057    this.hfileName = hfilePath.getName();
058    this.offset = offset;
059    this.blockType = blockType;
060  }
061
062  @Override
063  public int hashCode() {
064    return hfileName.hashCode() * 127 + (int) (offset ^ (offset >>> 32));
065  }
066
067  @Override
068  public boolean equals(Object o) {
069    if (o instanceof BlockCacheKey) {
070      BlockCacheKey k = (BlockCacheKey) o;
071      return offset == k.offset
072        && (hfileName == null ? k.hfileName == null : hfileName.equals(k.hfileName));
073    } else {
074      return false;
075    }
076  }
077
078  @Override
079  public String toString() {
080    return this.hfileName + '_' + this.offset;
081  }
082
083  public static final long FIXED_OVERHEAD = ClassSize.estimateBase(BlockCacheKey.class, false);
084
085  /**
086   * Strings have two bytes per character due to default Java Unicode encoding (hence length times
087   * 2).
088   */
089  @Override
090  public long heapSize() {
091    return ClassSize.align(FIXED_OVERHEAD + ClassSize.STRING + 2 * hfileName.length());
092  }
093
094  // can't avoid this unfortunately
095  /** Returns The hfileName portion of this cache key */
096  public String getHfileName() {
097    return hfileName;
098  }
099
100  public boolean isPrimary() {
101    return isPrimaryReplicaBlock;
102  }
103
104  public long getOffset() {
105    return offset;
106  }
107
108  public BlockType getBlockType() {
109    return blockType;
110  }
111
112  public void setBlockType(BlockType blockType) {
113    this.blockType = blockType;
114  }
115
116  public Path getFilePath() {
117    return filePath;
118  }
119
120}