// Copyright (C) 2015 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.change;
import com.google.common.collect.ListMultimap;
import com.google.common.collect.MultimapBuilder;
import com.google.gerrit.extensions.common.BlameInfo;
import com.google.gerrit.extensions.common.RangeInfo;
import com.google.gerrit.extensions.restapi.BadRequestException;
import com.google.gerrit.extensions.restapi.CacheControl;
import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
import com.google.gerrit.extensions.restapi.Response;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.extensions.restapi.RestReadView;
import com.google.gerrit.reviewdb.client.Project;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.gerrit.server.git.MergeUtil;
import com.google.gerrit.server.patch.AutoMerger;
import com.google.gerrit.server.project.InvalidChangeOperationException;
import com.google.gitiles.blame.BlameCache;
import com.google.gitiles.blame.Region;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import org.eclipse.jgit.lib.Config;
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.merge.ThreeWayMergeStrategy;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
import org.kohsuke.args4j.Option;
public class GetBlame implements RestReadView<FileResource> {
private final GitRepositoryManager repoManager;
private final BlameCache blameCache;
private final boolean allowBlame;
private final ThreeWayMergeStrategy mergeStrategy;
private final AutoMerger autoMerger;
@Option(
name = "--base",
aliases = {"-b"},
usage =
"whether to load the blame of the base revision (the direct"
+ " parent of the change) instead of the change"
)
private boolean base;
@Inject
GetBlame(
GitRepositoryManager repoManager,
BlameCache blameCache,
@GerritServerConfig Config cfg,
AutoMerger autoMerger) {
this.repoManager = repoManager;
this.blameCache = blameCache;
this.mergeStrategy = MergeUtil.getMergeStrategy(cfg);
this.autoMerger = autoMerger;
allowBlame = cfg.getBoolean("change", "allowBlame", true);
}
@Override
public Response<List<BlameInfo>> apply(FileResource resource)
throws RestApiException, OrmException, IOException, InvalidChangeOperationException {
if (!allowBlame) {
throw new BadRequestException("blame is disabled");
}
Project.NameKey project = resource.getRevision().getChange().getProject();
try (Repository repository = repoManager.openRepository(project);
ObjectInserter ins = repository.newObjectInserter();
ObjectReader reader = ins.newReader();
RevWalk revWalk = new RevWalk(reader)) {
String refName =
resource.getRevision().getEdit().isPresent()
? resource.getRevision().getEdit().get().getRefName()
: resource.getRevision().getPatchSet().getRefName();
Ref ref = repository.findRef(refName);
if (ref == null) {
throw new ResourceNotFoundException("unknown ref " + refName);
}
ObjectId objectId = ref.getObjectId();
RevCommit revCommit = revWalk.parseCommit(objectId);
RevCommit[] parents = revCommit.getParents();
String path = resource.getPatchKey().getFileName();
List<BlameInfo> result;
if (!base) {
result = blame(revCommit, path, repository, revWalk);
} else if (parents.length == 0) {
throw new ResourceNotFoundException("Initial commit doesn't have base");
} else if (parents.length == 1) {
result = blame(parents[0], path, repository, revWalk);
} else if (parents.length == 2) {
ObjectId automerge = autoMerger.merge(repository, revWalk, ins, revCommit, mergeStrategy);
result = blame(automerge, path, repository, revWalk);
} else {
throw new ResourceNotFoundException(
"Cannot generate blame for merge commit with more than 2 parents");
}
Response<List<BlameInfo>> r = Response.ok(result);
if (resource.isCacheable()) {
r.caching(CacheControl.PRIVATE(7, TimeUnit.DAYS));
}
return r;
}
}
private List<BlameInfo> blame(ObjectId id, String path, Repository repository, RevWalk revWalk)
throws IOException {
ListMultimap<BlameInfo, RangeInfo> ranges =
MultimapBuilder.hashKeys().arrayListValues().build();
List<BlameInfo> result = new ArrayList<>();
if (blameCache.findLastCommit(repository, id, path) == null) {
return result;
}
List<Region> blameRegions = blameCache.get(repository, id, path);
int from = 1;
for (Region region : blameRegions) {
RevCommit commit = revWalk.parseCommit(region.getSourceCommit());
BlameInfo blameInfo = toBlameInfo(commit, region.getSourceAuthor());
ranges.put(blameInfo, new RangeInfo(from, from + region.getCount() - 1));
from += region.getCount();
}
for (BlameInfo key : ranges.keySet()) {
key.ranges = ranges.get(key);
result.add(key);
}
return result;
}
private static BlameInfo toBlameInfo(RevCommit commit, PersonIdent sourceAuthor) {
BlameInfo blameInfo = new BlameInfo();
blameInfo.author = sourceAuthor.getName();
blameInfo.id = commit.getName();
blameInfo.commitMsg = commit.getFullMessage();
blameInfo.time = commit.getCommitTime();
return blameInfo;
}
}