Package com.google.gerrit.server.patch

Class AutoMerger

java.lang.Object

com.google.gerrit.server.patch.AutoMerger

public class AutoMerger
extends Object

Utility class for creating an auto-merge commit of a merge commit.

An auto-merge commit is the result of merging the 2 parents of a merge commit automatically. If there are conflicts the auto-merge commit contains Git conflict markers that indicate these conflicts.

Creating auto-merge commits for octopus merges (merge commits with more than 2 parents) is not supported. In this case the auto-merge is created between the first 2 parent commits.

All created auto-merge commits are stored in the repository of their merge commit as refs/cache-automerge/ branches. These branches serve:

• as a cache so that the each auto-merge gets computed only once
• as base for merge commits on which users can comment

The second point means that these commits are referenced from NoteDb. The consequence of this is that these refs should never be deleted.

Field Summary

Fields

Modifier and Type	Field	Description
static String	AUTO_MERGE_MSG_PREFIX

Method Summary

Modifier and Type	Method	Description
static boolean	cacheAutomerge(org.eclipse.jgit.lib.Config cfg)
Optional<org.eclipse.jgit.transport.ReceiveCommand>	createAutoMergeCommitIfNecessary(RepoView repoView, org.eclipse.jgit.revwalk.RevWalk rw, org.eclipse.jgit.lib.ObjectInserter ins, org.eclipse.jgit.revwalk.RevCommit maybeMergeCommit)	Creates an auto merge commit for the provided commit in case it is a merge commit.
org.eclipse.jgit.revwalk.RevCommit	lookupFromGitOrMergeInMemory(org.eclipse.jgit.lib.Repository repo, org.eclipse.jgit.revwalk.RevWalk rw, InMemoryInserter ins, org.eclipse.jgit.revwalk.RevCommit merge, org.eclipse.jgit.merge.ThreeWayMergeStrategy mergeStrategy)	Reads or creates an auto-merge commit of the parents of the given merge commit.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

AUTO_MERGE_MSG_PREFIX

public static final String AUTO_MERGE_MSG_PREFIX

See Also:

Constant Field Values

Method Detail

cacheAutomerge

public static boolean cacheAutomerge(org.eclipse.jgit.lib.Config cfg)

lookupFromGitOrMergeInMemory

public org.eclipse.jgit.revwalk.RevCommit lookupFromGitOrMergeInMemory(org.eclipse.jgit.lib.Repository repo,
                                                                       org.eclipse.jgit.revwalk.RevWalk rw,
                                                                       InMemoryInserter ins,
                                                                       org.eclipse.jgit.revwalk.RevCommit merge,
                                                                       org.eclipse.jgit.merge.ThreeWayMergeStrategy mergeStrategy)
                                                                throws IOException

Reads or creates an auto-merge commit of the parents of the given merge commit.

The result is read from Git or computed in-memory and not written back to Git. This method exists for backwards compatibility only. All new changes have their auto-merge commits written transactionally when the change or patch set is created.

Returns:

auto-merge commit. Headers of the returned RevCommit are parsed.

Throws:

IOException

createAutoMergeCommitIfNecessary

public Optional<org.eclipse.jgit.transport.ReceiveCommand> createAutoMergeCommitIfNecessary(RepoView repoView,
                                                                                            org.eclipse.jgit.revwalk.RevWalk rw,
                                                                                            org.eclipse.jgit.lib.ObjectInserter ins,
                                                                                            org.eclipse.jgit.revwalk.RevCommit maybeMergeCommit)
                                                                                     throws IOException

Creates an auto merge commit for the provided commit in case it is a merge commit. To be used whenever Gerrit creates new patch sets.

Callers need to include the returned ReceiveCommand in their ref transaction.

Returns:

A ReceiveCommand wrapped in an Optional to be used in a BatchRefUpdate. Optional.empty() in case we don't need an auto merge commit.

Throws:

IOException