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