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.hdfs.server.protocol; 019 020import org.apache.hadoop.hdfs.StorageType; 021 022import java.util.UUID; 023 024/** 025 * Class captures information of a storage in Datanode. 026 */ 027public class DatanodeStorage { 028 /** The state of the storage. */ 029 public enum State { 030 NORMAL, 031 READ_ONLY 032 } 033 034 private final String storageID; 035 private final State state; 036 private final StorageType storageType; 037 038 /** 039 * Create a storage with {@link State#NORMAL} and {@link StorageType#DEFAULT}. 040 * 041 * @param storageID 042 */ 043 public DatanodeStorage(String storageID) { 044 this(storageID, State.NORMAL, StorageType.DEFAULT); 045 } 046 047 public DatanodeStorage(String sid, State s, StorageType sm) { 048 this.storageID = sid; 049 this.state = s; 050 this.storageType = sm; 051 } 052 053 public String getStorageID() { 054 return storageID; 055 } 056 057 public State getState() { 058 return state; 059 } 060 061 public StorageType getStorageType() { 062 return storageType; 063 } 064 065 /** 066 * Generate new storage ID. The format of this string can be changed 067 * in the future without requiring that old storage IDs be updated. 068 * 069 * @return unique storage ID 070 */ 071 public static String generateUuid() { 072 return "DS-" + UUID.randomUUID(); 073 } 074 075 @Override 076 public boolean equals(Object other){ 077 if (other == this) { 078 return true; 079 } 080 081 if ((other == null) || 082 !(other instanceof DatanodeStorage)) { 083 return false; 084 } 085 DatanodeStorage otherStorage = (DatanodeStorage) other; 086 return otherStorage.getStorageID().compareTo(getStorageID()) == 0; 087 } 088 089 @Override 090 public int hashCode() { 091 return getStorageID().hashCode(); 092 } 093}