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.apache.directory.api.util.Strings;
025import org.slf4j.Logger;
026import 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 */
034public class ByteArrayComparator extends LdapComparator<byte[]>
035{
036    /** The serial version UID */
037    private static final long serialVersionUID = 2L;
038
039    /** A logger for this class */
040    private static final Logger LOG = LoggerFactory.getLogger( ByteArrayComparator.class );
041
042
043    /**
044     * The ByteArrayComparator constructor. Its OID is the OctetStringMatch matching
045     * rule OID.
046     * 
047     * @param oid The Comparator's OID
048     */
049    public ByteArrayComparator( String oid )
050    {
051        super( oid );
052    }
053
054
055    /**
056     * {@inheritDoc}
057     */
058    public int compare( byte[] b1, byte[] b2 )
059    {
060        LOG.debug( "comparing OctetString objects '{}' with '{}'",
061            Strings.dumpBytes( b1 ), Strings.dumpBytes( b2 ) );
062
063        // -------------------------------------------------------------------
064        // Handle some basis cases
065        // -------------------------------------------------------------------
066
067        if ( b1 == null )
068        {
069            return ( b2 == null ) ? 0 : -1;
070        }
071
072        if ( b2 == null )
073        {
074            return 1;
075        }
076
077        if ( b1.length == b2.length )
078        {
079            for ( int i = 0; i < b1.length; i++ )
080            {
081                if ( b1[i] > b2[i] )
082                {
083                    return 1;
084                }
085                else if ( b1[i] < b2[i] )
086                {
087                    return -1;
088                }
089            }
090
091            return 0;
092        }
093
094        int minLength = Math.min( b1.length, b2.length );
095
096        for ( int i = 0; i < minLength; i++ )
097        {
098            if ( b1[i] > b2[i] )
099            {
100                return 1;
101            }
102            else if ( b1[i] < b2[i] )
103            {
104                return -1;
105            }
106        }
107
108        // b2 is longer w/ b1 as prefix 
109        if ( b1.length == minLength )
110        {
111            return -1;
112        }
113
114        // b1 is longer w/ b2 as prefix
115        if ( b2.length == minLength )
116        {
117            return 1;
118        }
119
120        return 0;
121    }
122}