1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.directory.api.ldap.model.schema.comparators;
21
22
23 import org.apache.directory.api.i18n.I18n;
24 import org.apache.directory.api.ldap.model.schema.LdapComparator;
25 import org.slf4j.Logger;
26 import org.slf4j.LoggerFactory;
27
28
29 /**
30 * A class for the bitStringMatch matchingRule (RFC 4517, par. 4.2.1)
31 *
32 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
33 */
34 public class BitStringComparator extends LdapComparator<String>
35 {
36 /** The serial version UID */
37 private static final long serialVersionUID = 2L;
38
39 /** A logger for this class */
40 private static final Logger LOG = LoggerFactory.getLogger( BitStringComparator.class );
41
42
43 /**
44 * The BitStringComparator constructor. Its OID is the IntegerOrderingMatch matching
45 * rule OID.
46 *
47 * @param oid The Comparator's OID
48 */
49 public BitStringComparator( String oid )
50 {
51 super( oid );
52 }
53
54
55 /**
56 * {@inheritDoc}
57 */
58 public int compare( String bs1, String bs2 )
59 {
60 if ( LOG.isDebugEnabled() )
61 {
62 LOG.debug( I18n.msg( I18n.MSG_13743_COMPARING_BITSTRING, bs1, bs2 ) );
63 }
64
65 // First, shortcut the process by comparing
66 // references. If they are equals, then bs1 and bs2
67 // reference the same object
68 if ( bs1 == bs2 )
69 {
70 return 0;
71 }
72
73 // Then, deal with one of bs1 or bs2 being null
74 // Both can't be null, because then they would
75 // have been caught by the previous test
76 if ( ( bs1 == null ) || ( bs2 == null ) )
77 {
78 return bs1 == null ? -1 : 1;
79 }
80
81 // We have to get rid of 0 from left of each BitString
82 char[] array1 = bs1.toCharArray();
83 char[] array2 = bs2.toCharArray();
84
85 int pos1 = bs1.indexOf( '1' );
86 int pos2 = bs2.indexOf( '1' );
87
88 if ( pos1 == -1 )
89 {
90 if ( pos2 == -1 )
91 {
92 return 0;
93 }
94 else
95 {
96 return -1;
97 }
98 }
99 else if ( pos2 == -1 )
100 {
101 return 1;
102 }
103
104 int length1 = array1.length - pos1;
105 int length2 = array2.length - pos2;
106
107 if ( length1 == length2 )
108 {
109 for ( int i = 0; i < length1; i++ )
110 {
111 int i1 = i + pos1;
112 int i2 = i + pos2;
113
114 if ( array1[i1] < array2[i2] )
115 {
116 return -1;
117 }
118 else if ( array1[i1] > array2[i2] )
119 {
120 return 1;
121 }
122 }
123
124 return 0;
125 }
126
127 if ( length1 < length2 )
128 {
129 return -1;
130 }
131 else
132 {
133 return 1;
134 }
135 }
136 }