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     * @param oid The Comparator's OID
050     */
051    public ObjectIdentifierFirstComponentComparator( String oid )
052    {
053        super( oid );
054    }
055
056
057    /**
058     * Get the OID from the SchemaObject description
059     */
060    private String getNumericOid( String s )
061    {
062        // Get the OID from the strings now
063        int pos = 0;
064
065        if ( !Strings.isCharASCII( s, pos++, '(' ) )
066        {
067            return null;
068        }
069
070        while ( Strings.isCharASCII( s, pos, ' ' ) )
071        {
072            pos++;
073        }
074
075        int start = pos;
076
077        while ( Chars.isDigit( s, pos ) || Strings.isCharASCII( s, pos, '.' ) )
078        {
079            pos++;
080        }
081
082        String numericOid = s.substring( start, pos );
083
084        if ( Oid.isOid( numericOid ) )
085        {
086            return numericOid;
087        }
088        else
089        {
090            return null;
091        }
092    }
093
094
095    /**
096     * {@inheritDoc}
097     */
098    public int compare( String s1, String s2 )
099    {
100        LOG.debug( "comparing ObjectIdentifierFirstComponent objects '{}' with '{}'", s1, s2 );
101
102        // -------------------------------------------------------------------
103        // Handle some basis cases
104        // -------------------------------------------------------------------
105        if ( s1 == null )
106        {
107            return ( s2 == null ) ? 0 : -1;
108        }
109
110        if ( s2 == null )
111        {
112            return -1;
113        }
114
115        // Let's try to avoid a parse.
116        if ( s1.equals( s2 ) )
117        {
118            return 0;
119        }
120
121        // Get the OID from the strings now
122        String oid1 = getNumericOid( s1 );
123
124        if ( oid1 == null )
125        {
126            return -1;
127        }
128
129        String oid2 = getNumericOid( s2 );
130
131        if ( oid2 == null )
132        {
133            return -1;
134        }
135
136        if ( oid1.equals( oid2 ) )
137        {
138            return 0;
139        }
140        else
141        {
142            return -1;
143        }
144    }
145}