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.mavibot.btree;
21
22
23 import java.io.IOException;
24
25 import org.apache.directory.mavibot.btree.exception.EndOfFileExceededException;
26
27
28 /**
29 * A Cursor is used to fetch elements in a BTree and is returned by the
30 * @see BTree#browse method. The cursor <strng>must</strong> be closed
31 * when the user is done with it.
32 * <p>
33 *
34 * @param <V> The type for the stored value
35 *
36 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
37 */
38 public interface ValueCursor<V> extends Cursor<V>
39 {
40 /**
41 * Find the next key/value
42 *
43 * @return A Tuple containing the found key and value
44 * @throws IOException
45 * @throws EndOfFileExceededException
46 */
47 V next() throws EndOfFileExceededException, IOException;
48
49
50 /**
51 * Find the previous key/value
52 *
53 * @return A Tuple containing the found key and value
54 * @throws IOException
55 * @throws EndOfFileExceededException
56 */
57 V prev() throws EndOfFileExceededException, IOException;
58
59
60 /**
61 * @return The number of elements stored in the cursor
62 */
63 int size();
64 }