| // Copyright (C) 2016 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.util; |
| |
| import org.eclipse.jgit.errors.IncorrectObjectTypeException; |
| import org.eclipse.jgit.lib.ObjectId; |
| import org.eclipse.jgit.lib.Repository; |
| import org.eclipse.jgit.revwalk.RevCommit; |
| import org.eclipse.jgit.revwalk.RevWalk; |
| |
| import java.io.IOException; |
| |
| public class GitUtil { |
| |
| /** |
| * @param git |
| * @param commitId |
| * @param parentNum |
| * @return the {@code paretNo} parent of given commit or {@code null} |
| * when {@code parentNo} exceed number of {@code commitId} parents. |
| * @throws IncorrectObjectTypeException |
| * the supplied id is not a commit or an annotated tag. |
| * @throws IOException |
| * a pack file or loose object could not be read. |
| */ |
| public static RevCommit getParent(Repository git, |
| ObjectId commitId, int parentNum) throws IOException { |
| try (RevWalk walk = new RevWalk(git)) { |
| RevCommit commit = walk.parseCommit(commitId); |
| if (commit.getParentCount() > parentNum) { |
| return commit.getParent(parentNum); |
| } |
| } |
| return null; |
| } |
| |
| private GitUtil() { |
| } |
| } |