1 /*
2 * Copyright (C) 2019, Google LLC.
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;
44
45 import java.io.IOException;
46 import java.util.Collection;
47 import java.util.Optional;
48
49 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
50 import org.eclipse.jgit.errors.MissingObjectException;
51
52 /**
53 * Checks the reachability walking the graph from the starters towards the
54 * target.
55 */
56 class PedestrianReachabilityChecker implements ReachabilityChecker {
57
58 private final boolean topoSort;
59
60 private final RevWalk walk;
61
62 /**
63 * New instance of the reachability checker using a existing walk.
64 *
65 * @param topoSort
66 * walk commits in topological order
67 * @param walk
68 * RevWalk instance to reuse. Caller retains ownership.
69 */
70 public PedestrianReachabilityChecker(boolean topoSort,
71 RevWalk walk) {
72 this.topoSort = topoSort;
73 this.walk = walk;
74 }
75
76 @Override
77 public Optional<RevCommit> areAllReachable(Collection<RevCommit> targets,
78 Collection<RevCommit> starters)
79 throws MissingObjectException, IncorrectObjectTypeException,
80 IOException {
81 walk.reset();
82 if (topoSort) {
83 walk.sort(RevSort.TOPO);
84 }
85
86 for (RevCommit target: targets) {
87 walk.markStart(target);
88 }
89
90 for (RevCommit starter : starters) {
91 walk.markUninteresting(starter);
92 }
93
94 return Optional.ofNullable(walk.next());
95 }
96 }