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, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020package org.apache.directory.api.ldap.model.schema.comparators; 021 022 023import org.apache.directory.api.ldap.model.schema.LdapComparator; 024import org.slf4j.Logger; 025import org.slf4j.LoggerFactory; 026 027 028/** 029 * A class for the bitStringMatch matchingRule (RFC 4517, par. 4.2.1) 030 * 031 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 032 */ 033public class BitStringComparator extends LdapComparator<String> 034{ 035 /** The serial version UID */ 036 private static final long serialVersionUID = 2L; 037 038 /** A logger for this class */ 039 private static final Logger LOG = LoggerFactory.getLogger( BitStringComparator.class ); 040 041 042 /** 043 * The BitStringComparator constructor. Its OID is the IntegerOrderingMatch matching 044 * rule OID. 045 * 046 * @param oid The Comparator's OID 047 */ 048 public BitStringComparator( String oid ) 049 { 050 super( oid ); 051 } 052 053 054 /** 055 * {@inheritDoc} 056 */ 057 public int compare( String bs1, String bs2 ) 058 { 059 LOG.debug( "comparing BitString objects '{}' with '{}'", bs1, bs2 ); 060 061 // First, shortcut the process by comparing 062 // references. If they are equals, then bs1 and bs2 063 // reference the same object 064 if ( bs1 == bs2 ) 065 { 066 return 0; 067 } 068 069 // Then, deal with one of bs1 or bs2 being null 070 // Both can't be null, because then they would 071 // have been caught by the previous test 072 if ( ( bs1 == null ) || ( bs2 == null ) ) 073 { 074 return bs1 == null ? -1 : 1; 075 } 076 077 // We have to get rid of 0 from left of each BitString 078 char[] array1 = bs1.toCharArray(); 079 char[] array2 = bs2.toCharArray(); 080 081 int pos1 = bs1.indexOf( '1' ); 082 int pos2 = bs2.indexOf( '1' ); 083 084 if ( pos1 == -1 ) 085 { 086 if ( pos2 == -1 ) 087 { 088 return 0; 089 } 090 else 091 { 092 return -1; 093 } 094 } 095 else if ( pos2 == -1 ) 096 { 097 return 1; 098 } 099 100 int length1 = array1.length - pos1; 101 int length2 = array2.length - pos2; 102 103 if ( length1 == length2 ) 104 { 105 for ( int i = 0; i < length1; i++ ) 106 { 107 int i1 = i + pos1; 108 int i2 = i + pos2; 109 110 if ( array1[i1] < array2[i2] ) 111 { 112 return -1; 113 } 114 else if ( array1[i1] > array2[i2] ) 115 { 116 return 1; 117 } 118 } 119 120 return 0; 121 } 122 123 if ( length1 < length2 ) 124 { 125 return -1; 126 } 127 else 128 { 129 return 1; 130 } 131 } 132}