com.google.gerrit.server.git.MergeTip Maven / Gradle / Ivy
// Copyright (C) 2014 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.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.gerrit.common.Nullable;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import org.eclipse.jgit.lib.ObjectId;
/**
* Class describing a merge tip during merge operation.
*
* The current tip of a {@link MergeTip} may be null if the merge operation is against an unborn
* branch, and has not yet been attempted. This is distinct from a null {@link MergeTip} instance,
* which may be used to indicate that a merge failed or another error state.
*/
public class MergeTip {
private CodeReviewCommit initialTip;
private CodeReviewCommit branchTip;
private Map mergeResults;
/**
* @param initialTip tip before the merge operation; may be null, indicating an unborn branch.
* @param toMerge list of commits to be merged in merge operation; may not be null or empty.
*/
public MergeTip(@Nullable CodeReviewCommit initialTip, Collection toMerge) {
checkNotNull(toMerge, "toMerge may not be null");
checkArgument(!toMerge.isEmpty(), "toMerge may not be empty");
this.initialTip = initialTip;
this.branchTip = initialTip;
this.mergeResults = new HashMap<>();
// Assume fast-forward merge until opposite is proven.
for (CodeReviewCommit commit : toMerge) {
mergeResults.put(commit.copy(), commit.copy());
}
}
/**
* @return the initial tip of the branch before the merge operation started; may be null,
* indicating a previously unborn branch.
*/
public CodeReviewCommit getInitialTip() {
return initialTip;
}
/**
* Moves this MergeTip to newTip and appends mergeResult.
*
* @param newTip The new tip; may not be null.
* @param mergedFrom The result of the merge of {@code newTip}.
*/
public void moveTipTo(CodeReviewCommit newTip, ObjectId mergedFrom) {
checkArgument(newTip != null);
branchTip = newTip;
mergeResults.put(mergedFrom, newTip.copy());
}
/**
* The merge results of all the merges of this merge operation.
*
* @return The merge results of the merge operation as a map of SHA-1 to be merged to SHA-1 of the
* merge result.
*/
public Map getMergeResults() {
return mergeResults;
}
/**
* @return The current tip of the current merge operation; may be null, indicating an unborn
* branch.
*/
@Nullable
public CodeReviewCommit getCurrentTip() {
return branchTip;
}
}