1 /*
2 * Copyright (C) 2011, Google Inc.
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
44 package org.eclipse.jgit.blame;
45
46 import java.io.IOException;
47
48 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
49 import org.eclipse.jgit.errors.MissingObjectException;
50 import org.eclipse.jgit.lib.AnyObjectId;
51 import org.eclipse.jgit.lib.Repository;
52 import org.eclipse.jgit.revwalk.RevCommit;
53 import org.eclipse.jgit.revwalk.RevWalk;
54
55 final class ReverseWalk extends RevWalk {
56 ReverseWalk(Repository repo) {
57 super(repo);
58 }
59
60 @Override
61 public ReverseCommit next() throws MissingObjectException,
62 IncorrectObjectTypeException, IOException {
63 ReverseCommit c = (ReverseCommit) super.next();
64 if (c == null)
65 return null;
66 for (int pIdx = 0; pIdx < c.getParentCount(); pIdx++)
67 ((ReverseCommit) c.getParent(pIdx)).addChild(c);
68 return c;
69 }
70
71 @Override
72 protected RevCommit createCommit(AnyObjectId id) {
73 return new ReverseCommit(id);
74 }
75
76 static final class ReverseCommit extends RevCommit {
77 private static final ReverseCommit[] NO_CHILDREN = {};
78
79 private ReverseCommit[] children = NO_CHILDREN;
80
81 ReverseCommit(AnyObjectId id) {
82 super(id);
83 }
84
85 void addChild(ReverseCommit c) {
86 // Always put the most recent child onto the front of the list.
87 // This works correctly because our ReverseWalk parent (above)
88 // runs in COMMIT_TIME_DESC order. Older commits will be popped
89 // later and should go in front of the children list so they are
90 // visited first by BlameGenerator when considering candidates.
91
92 int cnt = children.length;
93 if (cnt == 0)
94 children = new ReverseCommit[] { c };
95 else if (cnt == 1)
96 children = new ReverseCommit[] { c, children[0] };
97 else {
98 ReverseCommit[] n = new ReverseCommit[1 + cnt];
99 n[0] = c;
100 System.arraycopy(children, 0, n, 1, cnt);
101 children = n;
102 }
103 }
104
105 int getChildCount() {
106 return children.length;
107 }
108
109 ReverseCommit getChild(final int nth) {
110 return children[nth];
111 }
112 }
113 }