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.asn1.util.Oid;
024import org.apache.directory.api.ldap.model.schema.LdapComparator;
025import org.apache.directory.api.util.Chars;
026import org.apache.directory.api.util.Strings;
027import org.slf4j.Logger;
028import org.slf4j.LoggerFactory;
029
030
031/**
032 * A comparator for Comparators. We compare the OIDs
033 * 
034 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
035 */
036public class ObjectIdentifierFirstComponentComparator extends LdapComparator<String>
037{
038    /** The serial version UID */
039    private static final long serialVersionUID = 2L;
040
041    /** A logger for this class */
042    private static final Logger LOG = LoggerFactory.getLogger( ObjectIdentifierFirstComponentComparator.class );
043
044
045    /**
046     * The ObjectIdentifierFirstComponentComparator constructor. Its OID is the 
047     * ObjectIdentifierFirstComponentMatch matching rule OID.
048     */
049    public ObjectIdentifierFirstComponentComparator( String oid )
050    {
051        super( oid );
052    }
053
054
055    /**
056     * Get the OID from the SchemaObject description
057     */
058    private String getNumericOid( String s )
059    {
060        // Get the OID from the strings now
061        int pos = 0;
062
063        if ( !Strings.isCharASCII( s, pos++, '(' ) )
064        {
065            return null;
066        }
067
068        while ( Strings.isCharASCII( s, pos, ' ' ) )
069        {
070            pos++;
071        }
072
073        int start = pos;
074
075        while ( Chars.isDigit( s, pos ) || Strings.isCharASCII( s, pos, '.' ) )
076        {
077            pos++;
078        }
079
080        String numericOid = s.substring( start, pos );
081
082        if ( Oid.isOid( numericOid ) )
083        {
084            return numericOid;
085        }
086        else
087        {
088            return null;
089        }
090    }
091
092
093    /**
094     * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
095     */
096    public int compare( String s1, String s2 )
097    {
098        LOG.debug( "comparing ObjectIdentifierFirstComponent objects '{}' with '{}'", s1, s2 );
099
100        // -------------------------------------------------------------------
101        // Handle some basis cases
102        // -------------------------------------------------------------------
103        if ( s1 == null )
104        {
105            return ( s2 == null ) ? 0 : -1;
106        }
107
108        if ( s2 == null )
109        {
110            return -1;
111        }
112
113        // Let's try to avoid a parse.
114        if ( s1.equals( s2 ) )
115        {
116            return 0;
117        }
118
119        // Get the OID from the strings now
120        String oid1 = getNumericOid( s1 );
121
122        if ( oid1 == null )
123        {
124            return -1;
125        }
126
127        String oid2 = getNumericOid( s2 );
128
129        if ( oid2 == null )
130        {
131            return -1;
132        }
133
134        if ( oid1.equals( oid2 ) )
135        {
136            return 0;
137        }
138        else
139        {
140            return -1;
141        }
142    }
143}