1 /*
2 * Copyright (C) 2011, Tomasz Zarna <Tomasz.Zarna@pl.ibm.com>
3 * and other copyright owners as documented in the project's IP log.
4 *
5 * This program and the accompanying materials are made available
6 * under the terms of the Eclipse Distribution License v1.0 which
7 * accompanies this distribution, is reproduced below, and is
8 * available at http://www.eclipse.org/org/documents/edl-v10.php
9 *
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 *
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials provided
22 * with the distribution.
23 *
24 * - Neither the name of the Eclipse Foundation, Inc. nor the
25 * names of its contributors may be used to endorse or promote
26 * products derived from this software without specific prior
27 * written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 */
43 package org.eclipse.jgit.revwalk.filter;
44
45 import java.io.IOException;
46
47 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
48 import org.eclipse.jgit.errors.MissingObjectException;
49 import org.eclipse.jgit.errors.StopWalkException;
50 import org.eclipse.jgit.internal.JGitText;
51 import org.eclipse.jgit.revwalk.RevCommit;
52 import org.eclipse.jgit.revwalk.RevWalk;
53
54 /**
55 * Filter that includes commits after a configured number are skipped.
56 */
57 public class SkipRevFilter extends RevFilter {
58
59 private final int skip;
60
61 private int count;
62
63 /**
64 * Create a new skip filter.
65 *
66 * @param skip
67 * the number of commits to skip
68 * @return a new filter
69 */
70 public static RevFilter create(int skip) {
71 if (skip < 0)
72 throw new IllegalArgumentException(
73 JGitText.get().skipMustBeNonNegative);
74 return new SkipRevFilter(skip);
75 }
76
77 private SkipRevFilter(int skip) {
78 this.skip = skip;
79 }
80
81 /** {@inheritDoc} */
82 @Override
83 public boolean include(RevWalk walker, RevCommit cmit)
84 throws StopWalkException, MissingObjectException,
85 IncorrectObjectTypeException, IOException {
86 if (skip > count++)
87 return false;
88 return true;
89 }
90
91 /** {@inheritDoc} */
92 @Override
93 public RevFilter clone() {
94 return new SkipRevFilter(skip);
95 }
96 }