diff options
Diffstat (limited to 'org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalkUtils.java')
-rw-r--r-- | org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalkUtils.java | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalkUtils.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalkUtils.java index 94400b06ed..83f5f924e5 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalkUtils.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalkUtils.java @@ -45,10 +45,16 @@ package org.eclipse.jgit.revwalk; import java.io.IOException; import java.util.ArrayList; +import java.util.Arrays; +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.AnyObjectId; +import org.eclipse.jgit.lib.ObjectId; +import org.eclipse.jgit.lib.ObjectIdSubclassMap; +import org.eclipse.jgit.lib.Ref; /** * Utility methods for {@link RevWalk}. @@ -124,4 +130,71 @@ public final class RevWalkUtils { 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 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 MissingObjectException + * @throws IncorrectObjectTypeException + * @throws IOException + */ + public static List<Ref> findBranchesReachableFrom(RevCommit commit, + RevWalk revWalk, Collection<Ref> refs) + throws MissingObjectException, IncorrectObjectTypeException, + IOException { + + List<Ref> result = new ArrayList<Ref>(); + // searches from branches can be cut off early if any parent of the + // search-for commit is found. This is quite likely, so optimize for this. + revWalk.markStart(Arrays.asList(commit.getParents())); + ObjectIdSubclassMap<ObjectId> cutOff = new ObjectIdSubclassMap<ObjectId>(); + + final int SKEW = 24*3600; // one day clock skew + + for (Ref ref : refs) { + RevCommit headCommit = revWalk.parseCommit(ref.getObjectId()); + + // 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; + + List<ObjectId> maybeCutOff = new ArrayList<ObjectId>(cutOff.size()); // guess rough size + revWalk.resetRetain(); + revWalk.markStart(headCommit); + RevCommit current; + Ref found = null; + while ((current = revWalk.next()) != null) { + if (AnyObjectId.equals(current, commit)) { + found = ref; + break; + } + if (cutOff.contains(current)) + break; + maybeCutOff.add(current.toObjectId()); + } + if (found != null) + result.add(ref); + else + for (ObjectId id : maybeCutOff) + cutOff.addIfAbsent(id); + + } + return result; + } + } |