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 */
020 package org.apache.directory.shared.ldap.schema.comparators;
021
022
023 import org.apache.directory.shared.ldap.schema.LdapComparator;
024 import org.apache.directory.shared.ldap.util.StringTools;
025 import org.slf4j.Logger;
026 import org.slf4j.LoggerFactory;
027
028
029 /**
030 * A comparator for byte[]s.
031 *
032 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
033 * @version $Rev$
034 */
035 public class ByteArrayComparator extends LdapComparator<byte[]>
036 {
037 /** A logger for this class */
038 private static final Logger LOG = LoggerFactory.getLogger( ByteArrayComparator.class );
039
040 /** The serialVersionUID */
041 private static final long serialVersionUID = 1L;
042
043 /**
044 * The ByteArrayComparator constructor. Its OID is the OctetStringMatch matching
045 * rule OID.
046 */
047 public ByteArrayComparator( String oid )
048 {
049 super( oid );
050 }
051
052 /**
053 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
054 */
055 public int compare( byte[] b1, byte[] b2 )
056 {
057 LOG.debug( "comparing OctetString objects '{}' with '{}'",
058 StringTools.dumpBytes( b1 ), StringTools.dumpBytes( b2 ) );
059
060 // -------------------------------------------------------------------
061 // Handle some basis cases
062 // -------------------------------------------------------------------
063
064 if ( b1 == null )
065 {
066 return ( b2 == null ) ? 0 : -1;
067 }
068
069 if ( b2 == null )
070 {
071 return 1;
072 }
073
074 if ( b1.length == b2.length )
075 {
076 for ( int i = 0; i < b1.length; i++ )
077 {
078 if ( b1[i] > b2[i] )
079 {
080 return 1;
081 }
082 else if ( b1[i] < b2[i] )
083 {
084 return -1;
085 }
086 }
087
088 return 0;
089 }
090
091 int minLength = Math.min( b1.length, b2.length );
092
093 for ( int i = 0; i < minLength; i++ )
094 {
095 if ( b1[i] > b2[i] )
096 {
097 return 1;
098 }
099 else if ( b1[i] < b2[i] )
100 {
101 return -1;
102 }
103 }
104
105 // b2 is longer w/ b1 as prefix
106 if ( b1.length == minLength )
107 {
108 return -1;
109 }
110
111 // b1 is longer w/ b2 as prefix
112 if ( b2.length == minLength )
113 {
114 return 1;
115 }
116
117 return 0;
118 }
119 }