RevWalkUtils.java
/*
* Copyright (C) 2011-2012, Robin Stocker <robin@nibor.org>
* 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
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*
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* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above
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package org.eclipse.jgit.revwalk;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.lib.Ref;
/**
* Utility methods for {@link org.eclipse.jgit.revwalk.RevWalk}.
*/
public final class RevWalkUtils {
private RevWalkUtils() {
// Utility class
}
/**
* Count the number of commits that are reachable from <code>start</code>
* until a commit that is reachable from <code>end</code> is encountered. In
* other words, count the number of commits that are in <code>start</code>,
* but not in <code>end</code>.
* <p>
* Note that this method calls
* {@link org.eclipse.jgit.revwalk.RevWalk#reset()} at the beginning. Also
* note that the existing rev filter on the walk is left as-is, so be sure
* to set the right rev filter before calling this method.
*
* @param walk
* the rev walk to use
* @param start
* the commit to start counting from
* @param end
* the commit where counting should end, or null if counting
* should be done until there are no more commits
* @return the number of commits
* @throws org.eclipse.jgit.errors.MissingObjectException
* @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
* @throws java.io.IOException
*/
public static int count(final RevWalk walk, final RevCommit start,
final RevCommit end) throws MissingObjectException,
IncorrectObjectTypeException, IOException {
return find(walk, start, end).size();
}
/**
* Find commits that are reachable from <code>start</code> until a commit
* that is reachable from <code>end</code> is encountered. In other words,
* Find of commits that are in <code>start</code>, but not in
* <code>end</code>.
* <p>
* Note that this method calls
* {@link org.eclipse.jgit.revwalk.RevWalk#reset()} at the beginning. Also
* note that the existing rev filter on the walk is left as-is, so be sure
* to set the right rev filter before calling this method.
*
* @param walk
* the rev walk to use
* @param start
* the commit to start counting from
* @param end
* the commit where counting should end, or null if counting
* should be done until there are no more commits
* @return the commits found
* @throws org.eclipse.jgit.errors.MissingObjectException
* @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
* @throws java.io.IOException
*/
public static List<RevCommit> find(final RevWalk walk,
final RevCommit start, final RevCommit end)
throws MissingObjectException, IncorrectObjectTypeException,
IOException {
walk.reset();
walk.markStart(start);
if (end != null)
walk.markUninteresting(end);
List<RevCommit> commits = new ArrayList<>();
for (RevCommit c : walk)
commits.add(c);
return commits;
}
/**
* Find the list of branches a given commit is reachable from when following
* parent.s
* <p>
* Note that this method calls
* {@link org.eclipse.jgit.revwalk.RevWalk#reset()} at the beginning.
* <p>
* In order to improve performance this method assumes clock skew among
* committers is never larger than 24 hours.
*
* @param commit
* the commit we are looking at
* @param revWalk
* The RevWalk to be used.
* @param refs
* the set of branches we want to see reachability from
* @return the list of branches a given commit is reachable from
* @throws org.eclipse.jgit.errors.MissingObjectException
* @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
* @throws java.io.IOException
*/
public static List<Ref> findBranchesReachableFrom(RevCommit commit,
RevWalk revWalk, Collection<Ref> refs)
throws MissingObjectException, IncorrectObjectTypeException,
IOException {
// Make sure commit is from the same RevWalk
commit = revWalk.parseCommit(commit.getId());
revWalk.reset();
List<Ref> result = new ArrayList<>();
final int SKEW = 24*3600; // one day clock skew
for (Ref ref : refs) {
RevObject maybehead = revWalk.parseAny(ref.getObjectId());
if (!(maybehead instanceof RevCommit))
continue;
RevCommit headCommit = (RevCommit) maybehead;
// if commit is in the ref branch, then the tip of ref should be
// newer than the commit we are looking for. Allow for a large
// clock skew.
if (headCommit.getCommitTime() + SKEW < commit.getCommitTime())
continue;
if (revWalk.isMergedInto(commit, headCommit))
result.add(ref);
}
return result;
}
}