blob: fd81396691b288d524dc3814708c6dd27e0ea653 [file] [log] [blame]
// Copyright 2019 Google LLC
//
// 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
//
// https://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.gitiles;
import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.util.Collection;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.RefDatabase;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
/**
* Checks for object visibility
*
* <p>Objects are visible if they are reachable from any of the references visible to the user.
*/
public class VisibilityChecker {
/**
* Check if any of the refs in {@code refDb} points to the object {@code id}.
*
* @param refDb a reference database
* @param id object we are looking for
* @return true if the any of the references in the db points directly to the id
* @throws IOException the reference space cannot be accessed
*/
protected boolean isTipOfBranch(RefDatabase refDb, ObjectId id) throws IOException {
// If any reference directly points at the requested object, permit display. Common for displays
// of pending patch sets in Gerrit Code Review, or bookmarks to the commit a tag points at.
return !refDb.getTipsWithSha1(id).isEmpty();
}
/**
* Check if {@code commit} is reachable starting from {@code starters}.
*
* @param description Description of the ids (e.g. "heads"). Mainly for tracing.
* @param walk The walk to use for the reachability check
* @param commit The starting commit. It *MUST* come from the walk in use
* @param starters visible commits. Anything reachable from these commits is visible. Missing ids
* or ids referring to other kinds of objects are ignored.
* @return true if we can get to {@code commit} from the {@code starters}
* @throws IOException a pack file or loose object could not be read
*/
protected boolean isReachableFrom(
String description, RevWalk walk, RevCommit commit, Collection<ObjectId> starters)
throws IOException {
if (starters.isEmpty()) {
return false;
}
ImmutableList<RevCommit> startCommits = objectIdsToCommits(walk, starters);
if (startCommits.isEmpty()) {
return false;
}
return !walk.createReachabilityChecker()
.areAllReachable(ImmutableList.of(commit), startCommits)
.isPresent();
}
private static ImmutableList<RevCommit> objectIdsToCommits(RevWalk walk, Collection<ObjectId> ids)
throws IOException {
ImmutableList.Builder<RevCommit> commits = ImmutableList.builder();
for (ObjectId id : ids) {
try {
commits.add(walk.parseCommit(id));
} catch (MissingObjectException e) {
// TODO(ifrade): ResolveParser has already checked that the object exists in the repo.
// Report as AssertionError.
} catch (IncorrectObjectTypeException e) {
// Ignore, doesn't affect commit reachability
}
}
return commits.build();
}
}