1 /*
2 * Copyright (C) 2011-2012, Robin Stocker <robin@nibor.org>
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.revwalk;
45
46 import java.io.IOException;
47 import java.util.ArrayList;
48 import java.util.Collection;
49 import java.util.List;
50
51 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
52 import org.eclipse.jgit.errors.MissingObjectException;
53 import org.eclipse.jgit.lib.Ref;
54
55 /**
56 * Utility methods for {@link org.eclipse.jgit.revwalk.RevWalk}.
57 */
58 public final class RevWalkUtils {
59
60 private RevWalkUtils() {
61 // Utility class
62 }
63
64 /**
65 * Count the number of commits that are reachable from <code>start</code>
66 * until a commit that is reachable from <code>end</code> is encountered. In
67 * other words, count the number of commits that are in <code>start</code>,
68 * but not in <code>end</code>.
69 * <p>
70 * Note that this method calls
71 * {@link org.eclipse.jgit.revwalk.RevWalk#reset()} at the beginning. Also
72 * note that the existing rev filter on the walk is left as-is, so be sure
73 * to set the right rev filter before calling this method.
74 *
75 * @param walk
76 * the rev walk to use
77 * @param start
78 * the commit to start counting from
79 * @param end
80 * the commit where counting should end, or null if counting
81 * should be done until there are no more commits
82 * @return the number of commits
83 * @throws org.eclipse.jgit.errors.MissingObjectException
84 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
85 * @throws java.io.IOException
86 */
87 public static int count(final RevWalk walk, final RevCommit start,
88 final RevCommit end) throws MissingObjectException,
89 IncorrectObjectTypeException, IOException {
90 return find(walk, start, end).size();
91 }
92
93 /**
94 * Find commits that are reachable from <code>start</code> until a commit
95 * that is reachable from <code>end</code> is encountered. In other words,
96 * Find of commits that are in <code>start</code>, but not in
97 * <code>end</code>.
98 * <p>
99 * Note that this method calls
100 * {@link org.eclipse.jgit.revwalk.RevWalk#reset()} at the beginning. Also
101 * note that the existing rev filter on the walk is left as-is, so be sure
102 * to set the right rev filter before calling this method.
103 *
104 * @param walk
105 * the rev walk to use
106 * @param start
107 * the commit to start counting from
108 * @param end
109 * the commit where counting should end, or null if counting
110 * should be done until there are no more commits
111 * @return the commits found
112 * @throws org.eclipse.jgit.errors.MissingObjectException
113 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
114 * @throws java.io.IOException
115 */
116 public static List<RevCommit> find(final RevWalk walk,
117 final RevCommit start, final RevCommit end)
118 throws MissingObjectException, IncorrectObjectTypeException,
119 IOException {
120 walk.reset();
121 walk.markStart(start);
122 if (end != null)
123 walk.markUninteresting(end);
124
125 List<RevCommit> commits = new ArrayList<>();
126 for (RevCommit c : walk)
127 commits.add(c);
128 return commits;
129 }
130
131 /**
132 * Find the list of branches a given commit is reachable from when following
133 * parent.s
134 * <p>
135 * Note that this method calls
136 * {@link org.eclipse.jgit.revwalk.RevWalk#reset()} at the beginning.
137 * <p>
138 * In order to improve performance this method assumes clock skew among
139 * committers is never larger than 24 hours.
140 *
141 * @param commit
142 * the commit we are looking at
143 * @param revWalk
144 * The RevWalk to be used.
145 * @param refs
146 * the set of branches we want to see reachability from
147 * @return the list of branches a given commit is reachable from
148 * @throws org.eclipse.jgit.errors.MissingObjectException
149 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
150 * @throws java.io.IOException
151 */
152 public static List<Ref> findBranchesReachableFrom(RevCommit commit,
153 RevWalk revWalk, Collection<Ref> refs)
154 throws MissingObjectException, IncorrectObjectTypeException,
155 IOException {
156
157 // Make sure commit is from the same RevWalk
158 commit = revWalk.parseCommit(commit.getId());
159 revWalk.reset();
160 List<Ref> result = new ArrayList<>();
161
162 final int SKEW = 24*3600; // one day clock skew
163
164 for (Ref ref : refs) {
165 RevObject maybehead = revWalk.parseAny(ref.getObjectId());
166 if (!(maybehead instanceof RevCommit))
167 continue;
168 RevCommit headCommit = (RevCommit) maybehead;
169
170 // if commit is in the ref branch, then the tip of ref should be
171 // newer than the commit we are looking for. Allow for a large
172 // clock skew.
173 if (headCommit.getCommitTime() + SKEW < commit.getCommitTime())
174 continue;
175
176 if (revWalk.isMergedInto(commit, headCommit))
177 result.add(ref);
178 }
179 return result;
180 }
181
182 }