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.fs; 019 020 import org.apache.commons.codec.binary.Base64; 021 import org.apache.commons.lang.builder.EqualsBuilder; 022 import org.apache.commons.lang.builder.HashCodeBuilder; 023 import org.apache.hadoop.classification.InterfaceAudience; 024 import org.apache.hadoop.classification.InterfaceStability; 025 026 /** 027 * HDFS-specific volume identifier which implements {@link VolumeId}. Can be 028 * used to differentiate between the data directories on a single datanode. This 029 * identifier is only unique on a per-datanode basis. 030 */ 031 @InterfaceStability.Unstable 032 @InterfaceAudience.Public 033 public class HdfsVolumeId implements VolumeId { 034 035 private final byte[] id; 036 private final boolean isValid; 037 038 public HdfsVolumeId(byte[] id, boolean isValid) { 039 this.id = id; 040 this.isValid = isValid; 041 } 042 043 @Override 044 public boolean isValid() { 045 return isValid; 046 } 047 048 @Override 049 public int compareTo(VolumeId arg0) { 050 return hashCode() - arg0.hashCode(); 051 } 052 053 @Override 054 public int hashCode() { 055 return new HashCodeBuilder().append(id).toHashCode(); 056 } 057 058 @Override 059 public boolean equals(Object obj) { 060 if (obj == null || obj.getClass() != getClass()) { 061 return false; 062 } 063 if (obj == this) { 064 return true; 065 } 066 067 HdfsVolumeId that = (HdfsVolumeId) obj; 068 return new EqualsBuilder().append(this.id, that.id).isEquals(); 069 } 070 071 @Override 072 public String toString() { 073 return Base64.encodeBase64String(id); 074 } 075 }