com.google.gerrit.server.git.NotesBranchUtil Maven / Gradle / Ivy
// Copyright (C) 2012 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.gerrit.server.git;
import static com.google.common.base.MoreObjects.firstNonNull;
import com.google.gerrit.reviewdb.client.Project;
import com.google.gerrit.server.GerritPersonIdent;
import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
import com.google.gerrit.server.update.RefUpdateUtil;
import com.google.inject.Inject;
import com.google.inject.assistedinject.Assisted;
import java.io.IOException;
import org.eclipse.jgit.lib.BatchRefUpdate;
import org.eclipse.jgit.lib.CommitBuilder;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectInserter;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.notes.Note;
import org.eclipse.jgit.notes.NoteMap;
import org.eclipse.jgit.notes.NoteMerger;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.transport.ReceiveCommand;
/** A utility class for updating a notes branch with automatic merge of note trees. */
public class NotesBranchUtil {
public interface Factory {
NotesBranchUtil create(Project.NameKey project, Repository db, ObjectInserter inserter);
}
private final PersonIdent gerritIdent;
private final GitReferenceUpdated gitRefUpdated;
private final Project.NameKey project;
private final Repository db;
private final ObjectInserter inserter;
private RevCommit baseCommit;
private NoteMap base;
private RevCommit oursCommit;
private NoteMap ours;
private RevWalk revWalk;
private ObjectReader reader;
private boolean overwrite;
private ReviewNoteMerger noteMerger;
@Inject
public NotesBranchUtil(
@GerritPersonIdent PersonIdent gerritIdent,
GitReferenceUpdated gitRefUpdated,
@Assisted Project.NameKey project,
@Assisted Repository db,
@Assisted ObjectInserter inserter) {
this.gerritIdent = gerritIdent;
this.gitRefUpdated = gitRefUpdated;
this.project = project;
this.db = db;
this.inserter = inserter;
}
/**
* Create a new commit in the {@code notesBranch} by updating existing or creating new notes from
* the {@code notes} map.
*
* Does not retry in the case of lock failure; callers may use {@link
* com.google.gerrit.server.update.RetryHelper}.
*
* @param notes map of notes
* @param notesBranch notes branch to update
* @param commitAuthor author of the commit in the notes branch
* @param commitMessage for the commit in the notes branch
* @throws LockFailureException if committing the notes failed due to a lock failure on the notes
* branch
* @throws IOException if committing the notes failed for any other reason
*/
public final void commitAllNotes(
NoteMap notes, String notesBranch, PersonIdent commitAuthor, String commitMessage)
throws IOException {
this.overwrite = true;
commitNotes(notes, notesBranch, commitAuthor, commitMessage);
}
/**
* Create a new commit in the {@code notesBranch} by creating not yet existing notes from the
* {@code notes} map. The notes from the {@code notes} map which already exist in the note-tree of
* the tip of the {@code notesBranch} will not be updated.
*
*
Does not retry in the case of lock failure; callers may use {@link
* com.google.gerrit.server.update.RetryHelper}.
*
* @param notes map of notes
* @param notesBranch notes branch to update
* @param commitAuthor author of the commit in the notes branch
* @param commitMessage for the commit in the notes branch
* @return map with those notes from the {@code notes} that were newly created
* @throws LockFailureException if committing the notes failed due to a lock failure on the notes
* branch
* @throws IOException if committing the notes failed for any other reason
*/
public final NoteMap commitNewNotes(
NoteMap notes, String notesBranch, PersonIdent commitAuthor, String commitMessage)
throws IOException {
this.overwrite = false;
commitNotes(notes, notesBranch, commitAuthor, commitMessage);
NoteMap newlyCreated = NoteMap.newEmptyMap();
for (Note n : notes) {
if (base == null || !base.contains(n)) {
newlyCreated.set(n, n.getData());
}
}
return newlyCreated;
}
private void commitNotes(
NoteMap notes, String notesBranch, PersonIdent commitAuthor, String commitMessage)
throws LockFailureException, IOException {
try {
revWalk = new RevWalk(db);
reader = db.newObjectReader();
loadBase(notesBranch);
if (overwrite) {
addAllNotes(notes);
} else {
addNewNotes(notes);
}
if (base != null) {
oursCommit = createCommit(ours, commitAuthor, commitMessage, baseCommit);
} else {
oursCommit = createCommit(ours, commitAuthor, commitMessage);
}
updateRef(notesBranch);
} finally {
revWalk.close();
reader.close();
}
}
private void addNewNotes(NoteMap notes) throws IOException {
for (Note n : notes) {
if (!ours.contains(n)) {
ours.set(n, n.getData());
}
}
}
private void addAllNotes(NoteMap notes) throws IOException {
for (Note n : notes) {
if (ours.contains(n)) {
// Merge the existing and the new note as if they are both new,
// means: base == null
// There is no really a common ancestry for these two note revisions
ObjectId noteContent =
getNoteMerger().merge(null, n, ours.getNote(n), reader, inserter).getData();
ours.set(n, noteContent);
} else {
ours.set(n, n.getData());
}
}
}
private NoteMerger getNoteMerger() {
if (noteMerger == null) {
noteMerger = new ReviewNoteMerger();
}
return noteMerger;
}
private void loadBase(String notesBranch) throws IOException {
Ref branch = db.getRefDatabase().exactRef(notesBranch);
if (branch != null) {
baseCommit = revWalk.parseCommit(branch.getObjectId());
base = NoteMap.read(revWalk.getObjectReader(), baseCommit);
}
if (baseCommit != null) {
ours = NoteMap.read(revWalk.getObjectReader(), baseCommit);
} else {
ours = NoteMap.newEmptyMap();
}
}
private RevCommit createCommit(
NoteMap map, PersonIdent author, String message, RevCommit... parents) throws IOException {
CommitBuilder b = new CommitBuilder();
b.setTreeId(map.writeTree(inserter));
b.setAuthor(author != null ? author : gerritIdent);
b.setCommitter(gerritIdent);
if (parents.length > 0) {
b.setParentIds(parents);
}
b.setMessage(message);
ObjectId commitId = inserter.insert(b);
inserter.flush();
return revWalk.parseCommit(commitId);
}
private void updateRef(String notesBranch) throws LockFailureException, IOException {
if (baseCommit != null && oursCommit.getTree().equals(baseCommit.getTree())) {
// If the trees are identical, there is no change in the notes.
// Avoid saving this commit as it has no new information.
return;
}
BatchRefUpdate bru = db.getRefDatabase().newBatchUpdate();
bru.addCommand(
new ReceiveCommand(firstNonNull(baseCommit, ObjectId.zeroId()), oursCommit, notesBranch));
RefUpdateUtil.executeChecked(bru, revWalk);
gitRefUpdated.fire(project, bru, null);
}
}