1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 * 19 */ 20 package org.apache.directory.mavibot.btree; 21 22 23 import java.util.Comparator; 24 25 26 /** 27 * A comparator for the RevisionName class 28 * 29 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 30 */ 31 /* no qualifier*/class NameRevisionComparator implements Comparator<NameRevision> 32 { 33 /** A static instance of a NameRevisionComparator */ 34 public static final NameRevisionComparator INSTANCE = new NameRevisionComparator(); 35 36 /** 37 * A private constructor of the NameRevisionComparator class 38 */ 39 private NameRevisionComparator() 40 { 41 } 42 43 44 /** 45 * {@inheritDoc} 46 */ 47 public int compare( NameRevision rn1, NameRevision rn2 ) 48 { 49 if ( rn1 == rn2 ) 50 { 51 return 0; 52 } 53 54 // First compare the name 55 int comp = rn1.getName().compareTo( rn2.getName() ); 56 57 if ( comp < 0 ) 58 { 59 return -1; 60 } 61 else if ( comp > 0 ) 62 { 63 return 1; 64 } 65 66 if ( rn1.getRevision() < rn2.getRevision() ) 67 { 68 return -1; 69 } 70 else if ( rn1.getRevision() > rn2.getRevision() ) 71 { 72 return 1; 73 } 74 75 // The name are equal : check the revision 76 if ( rn1.getRevision() < rn2.getRevision() ) 77 { 78 return -1; 79 } 80 else if ( rn1.getRevision() > rn2.getRevision() ) 81 { 82 return 1; 83 } 84 85 return 0; 86 } 87 }