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.fs;
019
020import org.apache.hadoop.classification.InterfaceAudience;
021import org.apache.hadoop.classification.InterfaceStability;
022
023/**
024 * Opaque interface that identifies a disk location. Subclasses
025 * should implement {@link Comparable} and override both equals and hashCode.
026 */
027@InterfaceStability.Unstable
028@InterfaceAudience.Public
029public interface VolumeId extends Comparable<VolumeId> {
030
031  @Override
032  abstract public int compareTo(VolumeId arg0);
033
034  @Override
035  abstract public int hashCode();
036
037  @Override
038  abstract public boolean equals(Object obj);
039
040}