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 * http://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.server.core.partition.impl.btree;
21
22
23 import java.io.Serializable;
24
25 import org.apache.directory.server.schema.SerializableComparator;
26
27
28 /**
29 * A TupleComparator that compares keys only.
30 *
31 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
32 * @version $Rev: 610243 $
33 */
34 public class KeyOnlyComparator<K,V> implements TupleComparator<K,V>, Serializable
35 {
36 private static final long serialVersionUID = 3544956549803161397L;
37
38 private SerializableComparator<K> keyComparator;
39
40
41 public KeyOnlyComparator( SerializableComparator<K> comparator )
42 {
43 keyComparator = comparator;
44 }
45
46
47 /**
48 * Gets the comparator used to compare keys. May be null in which
49 * case the compareKey method will throw an UnsupportedOperationException.
50 *
51 * @return the comparator for comparing keys.
52 */
53 public SerializableComparator<K> getKeyComparator()
54 {
55 return keyComparator;
56 }
57
58
59 /**
60 * Will throw an UnsupportedOperationException every time.
61 */
62 public SerializableComparator<V> getValueComparator()
63 {
64 throw new UnsupportedOperationException();
65 }
66
67
68 /**
69 * Compares key Object to determine their sorting order returning a
70 * value = to, < or > than 0.
71 *
72 * @param key1 the first key to compare
73 * @param key2 the other key to compare to the first
74 * @return 0 if both are equal, a negative value less than 0 if the first
75 * is less than the second, or a postive value if the first is greater than
76 * the second byte array.
77 */
78 public int compareKey( K key1, K key2 )
79 {
80 return keyComparator.compare( key1, key2 );
81 }
82
83
84 /**
85 * Comparse value Objects to determine their sorting order returning a
86 * value = to, < or > than 0.
87 *
88 * @param value1 the first value to compare
89 * @param value2 the other value to compare to the first
90 * @return 0 if both are equal, a negative value less than 0 if the first
91 * is less than the second, or a postive value if the first is greater than
92 * the second Object.
93 */
94 public int compareValue( V value1, V value2 )
95 {
96 throw new UnsupportedOperationException();
97 }
98 }