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.xdbm;
21
22
23 import org.apache.directory.server.core.cursor.Cursor;
24
25
26 /**
27 * A Cursor introducing new advance methods designed to reduce some
28 * inefficiencies encountered when scanning over Tuples.
29 *
30 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
31 * @version $Rev$
32 */
33 public interface IndexCursor<V,E> extends Cursor<IndexEntry<V,E>>
34 {
35 /**
36 * An alternative to calling before(IndexEntry) which often may require
37 * wrapping an id and value in a newly created IndexEntry object that may
38 * be an unnecessary object creation. Some implementations may not
39 * support this operation and may throw an UnsupportedOperationEception.
40 *
41 * @param id the Long id for the entry
42 * @param indexValue the value to advance just before
43 * @throws Exception if there are faults peforming this operation
44 */
45 void beforeValue( Long id, V indexValue ) throws Exception;
46
47
48 /**
49 * An alternative to calling after(IndexEntry) which often may require
50 * wrapping an id and value in a newly created IndexEntry object that may
51 * be an unnecessary object creation. Some implementations may not
52 * support this operation and may throw an UnsupportedOperationEception.
53 *
54 * @param id the Long id for the entry
55 * @param indexValue the value to advance just after the last value
56 * @throws Exception if there are faults peforming this operation
57 */
58 void afterValue( Long id, V indexValue ) throws Exception;
59 }