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 <ifrade@google.com>tags/v5.4.0.201905221418-m3
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/* | |||
* 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<FileRepository> repository) { | |||
return new PedestrianReachabilityChecker(true, repository.getRevWalk()); | |||
} | |||
} |
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/* | |||
* 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<FileRepository> repository) throws Exception; | |||
TestRepository<FileRepository> 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<RevCommit> result) { | |||
assertFalse(msg, result.isPresent()); | |||
} | |||
private static void assertUnreachable(String msg, | |||
Optional<RevCommit> result) { | |||
assertTrue(msg, result.isPresent()); | |||
} | |||
} |
@@ -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<RevCommit> areAllReachable(Collection<RevCommit> targets, | |||
Collection<RevCommit> 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()); | |||
} | |||
} |
@@ -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. | |||
* <p> | |||
* 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. | |||
* <p> | |||
* 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<RevCommit> areAllReachable(Collection<RevCommit> targets, | |||
Collection<RevCommit> starters) | |||
throws MissingObjectException, IncorrectObjectTypeException, | |||
IOException; | |||
} |