From 4e196faa1bbe8b4c061662d70479d2b189b4082f Mon Sep 17 00:00:00 2001 From: Ivan Frade Date: Mon, 22 Apr 2019 11:37:43 -0700 Subject: [PATCH] ReachabilityChecker: Default implementation with a RevWalk It is common to check if a certain commit is reachable from some starting points. For example gitiles does it to check if a commit is visible to a user based on its permissions. Offer this functionality in JGit. Split the interface as the next commit will introduce an implementation using bitmap indices. Change-Id: I0933b305c8d734f7a64502910ff4d9ef4fc92ae1 Signed-off-by: Ivan Frade --- .../PedestrianReachabilityCheckerTest.java | 57 ++++++ .../revwalk/ReachabilityCheckerTestCase.java | 168 ++++++++++++++++++ .../PedestrianReachabilityChecker.java | 98 ++++++++++ .../jgit/revwalk/ReachabilityChecker.java | 90 ++++++++++ 4 files changed, 413 insertions(+) create mode 100644 org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/PedestrianReachabilityCheckerTest.java create mode 100644 org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/ReachabilityCheckerTestCase.java create mode 100644 org.eclipse.jgit/src/org/eclipse/jgit/revwalk/PedestrianReachabilityChecker.java create mode 100644 org.eclipse.jgit/src/org/eclipse/jgit/revwalk/ReachabilityChecker.java diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/PedestrianReachabilityCheckerTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/PedestrianReachabilityCheckerTest.java new file mode 100644 index 000000000..8d3e78c1f --- /dev/null +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/PedestrianReachabilityCheckerTest.java @@ -0,0 +1,57 @@ +/* + * Copyright (C) 2019, Google LLC. + * and other copyright owners as documented in the project's IP log. + * + * This program and the accompanying materials are made available + * under the terms of the Eclipse Distribution License v1.0 which + * accompanies this distribution, is reproduced below, and is + * available at http://www.eclipse.org/org/documents/edl-v10.php + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * - Neither the name of the Eclipse Foundation, Inc. nor the + * names of its contributors may be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +package org.eclipse.jgit.revwalk; + +import org.eclipse.jgit.internal.storage.file.FileRepository; +import org.eclipse.jgit.junit.TestRepository; + +public class PedestrianReachabilityCheckerTest + extends ReachabilityCheckerTestCase { + + @Override + protected ReachabilityChecker getChecker( + TestRepository repository) { + return new PedestrianReachabilityChecker(true, repository.getRevWalk()); + } + +} diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/ReachabilityCheckerTestCase.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/ReachabilityCheckerTestCase.java new file mode 100644 index 000000000..dd73e3572 --- /dev/null +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/ReachabilityCheckerTestCase.java @@ -0,0 +1,168 @@ +/* + * Copyright (C) 2019, Google LLC. + * and other copyright owners as documented in the project's IP log. + * + * This program and the accompanying materials are made available + * under the terms of the Eclipse Distribution License v1.0 which + * accompanies this distribution, is reproduced below, and is + * available at http://www.eclipse.org/org/documents/edl-v10.php + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * - Neither the name of the Eclipse Foundation, Inc. nor the + * names of its contributors may be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +package org.eclipse.jgit.revwalk; + +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertTrue; + +import java.util.Arrays; +import java.util.Optional; + +import org.eclipse.jgit.internal.storage.file.FileRepository; +import org.eclipse.jgit.junit.LocalDiskRepositoryTestCase; +import org.eclipse.jgit.junit.TestRepository; +import org.junit.Before; +import org.junit.Test; + +public abstract class ReachabilityCheckerTestCase + extends LocalDiskRepositoryTestCase { + + protected abstract ReachabilityChecker getChecker( + TestRepository repository) throws Exception; + + TestRepository repo; + + /** {@inheritDoc} */ + @Override + @Before + public void setUp() throws Exception { + super.setUp(); + FileRepository db = createWorkRepository(); + repo = new TestRepository<>(db); + } + + @Test + public void reachable() throws Exception { + RevCommit a = repo.commit().create(); + RevCommit b1 = repo.commit(a); + RevCommit b2 = repo.commit(b1); + RevCommit c1 = repo.commit(a); + RevCommit c2 = repo.commit(c1); + repo.update("refs/heads/checker", b2); + + ReachabilityChecker checker = getChecker(repo); + + assertReachable("reachable from one tip", + checker.areAllReachable(Arrays.asList(a), Arrays.asList(c2))); + assertReachable("reachable from another tip", + checker.areAllReachable(Arrays.asList(a), Arrays.asList(b2))); + assertReachable("reachable from itself", + checker.areAllReachable(Arrays.asList(a), Arrays.asList(b2))); + } + + @Test + public void reachable_merge() throws Exception { + RevCommit a = repo.commit().create(); + RevCommit b1 = repo.commit(a); + RevCommit b2 = repo.commit(b1); + RevCommit c1 = repo.commit(a); + RevCommit c2 = repo.commit(c1); + RevCommit merge = repo.commit(c2, b2); + repo.update("refs/heads/checker", merge); + + ReachabilityChecker checker = getChecker(repo); + + assertReachable("reachable through one branch", + checker.areAllReachable(Arrays.asList(b1), + Arrays.asList(merge))); + assertReachable("reachable through another branch", + checker.areAllReachable(Arrays.asList(c1), + Arrays.asList(merge))); + assertReachable("reachable, before the branching", + checker.areAllReachable(Arrays.asList(a), + Arrays.asList(merge))); + } + + @Test + public void unreachable_isLaterCommit() throws Exception { + RevCommit a = repo.commit().create(); + RevCommit b1 = repo.commit(a); + RevCommit b2 = repo.commit(b1); + repo.update("refs/heads/checker", b2); + + ReachabilityChecker checker = getChecker(repo); + + assertUnreachable("unreachable from the future", + checker.areAllReachable(Arrays.asList(b2), Arrays.asList(b1))); + } + + @Test + public void unreachable_differentBranch() throws Exception { + RevCommit a = repo.commit().create(); + RevCommit b1 = repo.commit(a); + RevCommit b2 = repo.commit(b1); + RevCommit c1 = repo.commit(a); + repo.update("refs/heads/checker", b2); + + ReachabilityChecker checker = getChecker(repo); + + assertUnreachable("unreachable from different branch", + checker.areAllReachable(Arrays.asList(c1), Arrays.asList(b2))); + } + + @Test + public void reachable_longChain() throws Exception { + RevCommit root = repo.commit().create(); + RevCommit head = root; + for (int i = 0; i < 10000; i++) { + head = repo.commit(head); + } + repo.update("refs/heads/master", head); + + ReachabilityChecker checker = getChecker(repo); + + assertReachable("reachable with long chain in the middle", checker + .areAllReachable(Arrays.asList(root), Arrays.asList(head))); + } + + private static void assertReachable(String msg, + Optional result) { + assertFalse(msg, result.isPresent()); + } + + private static void assertUnreachable(String msg, + Optional result) { + assertTrue(msg, result.isPresent()); + } + +} diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/PedestrianReachabilityChecker.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/PedestrianReachabilityChecker.java new file mode 100644 index 000000000..2704b69cb --- /dev/null +++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/PedestrianReachabilityChecker.java @@ -0,0 +1,98 @@ +/* + * Copyright (C) 2019, Google LLC. + * and other copyright owners as documented in the project's IP log. + * + * This program and the accompanying materials are made available + * under the terms of the Eclipse Distribution License v1.0 which + * accompanies this distribution, is reproduced below, and is + * available at http://www.eclipse.org/org/documents/edl-v10.php + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * - Neither the name of the Eclipse Foundation, Inc. nor the + * names of its contributors may be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +package org.eclipse.jgit.revwalk; + +import java.io.IOException; +import java.util.Collection; +import java.util.Optional; + +import org.eclipse.jgit.errors.IncorrectObjectTypeException; +import org.eclipse.jgit.errors.MissingObjectException; + +/** + * Checks the reachability walking the graph from the starters towards the + * target. + * + * @since 5.5 + */ +public class PedestrianReachabilityChecker implements ReachabilityChecker { + + private final boolean topoSort; + + private final RevWalk walk; + + /** + * New instance of the reachability checker using a existing walk. + * + * @param topoSort + * walk commits in topological order + * @param walk + * RevWalk instance to reuse. Caller retains ownership. + */ + public PedestrianReachabilityChecker(boolean topoSort, + RevWalk walk) { + this.topoSort = topoSort; + this.walk = walk; + } + + @Override + public Optional areAllReachable(Collection targets, + Collection starters) + throws MissingObjectException, IncorrectObjectTypeException, + IOException { + walk.reset(); + if (topoSort) { + walk.sort(RevSort.TOPO); + } + + for (RevCommit target: targets) { + walk.markStart(target); + } + + for (RevCommit starter : starters) { + walk.markUninteresting(starter); + } + + return Optional.ofNullable(walk.next()); + } +} diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/ReachabilityChecker.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/ReachabilityChecker.java new file mode 100644 index 000000000..cf5f4a28c --- /dev/null +++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/ReachabilityChecker.java @@ -0,0 +1,90 @@ +/* + * Copyright (C) 2019, Google LLC. + * and other copyright owners as documented in the project's IP log. + * + * This program and the accompanying materials are made available + * under the terms of the Eclipse Distribution License v1.0 which + * accompanies this distribution, is reproduced below, and is + * available at http://www.eclipse.org/org/documents/edl-v10.php + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * - Neither the name of the Eclipse Foundation, Inc. nor the + * names of its contributors may be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +package org.eclipse.jgit.revwalk; + +import java.io.IOException; +import java.util.Collection; +import java.util.Optional; + +import org.eclipse.jgit.errors.IncorrectObjectTypeException; +import org.eclipse.jgit.errors.MissingObjectException; + +/** + * Check if a commit is reachable from a collection of starting commits. + *

+ * Note that this checks the reachability of commits (and tags). Trees, blobs or + * any other object will cause IncorrectObjectTypeException exceptions. + * + * @since 5.5 + */ +public interface ReachabilityChecker { + + /** + * Check if all targets are reachable from the {@code starter} commits. + *

+ * Caller should parse the objectIds (preferably with + * {@code walk.parseCommit()} and handle missing/incorrect type objects + * before calling this method. + * + * @param targets + * commits to reach. + * @param starters + * known starting points. + * @return An unreachable target if at least one of the targets is + * unreachable. An empty optional if all targets are reachable from + * the starters. + * + * @throws MissingObjectException + * if any of the incoming objects doesn't exist in the + * repository. + * @throws IncorrectObjectTypeException + * if any of the incoming objects is not a commit or a tag. + * @throws IOException + * if any of the underlying indexes or readers can not be + * opened. + */ + Optional areAllReachable(Collection targets, + Collection starters) + throws MissingObjectException, IncorrectObjectTypeException, + IOException; +}