https://www.eclipse.org/jgit//org.eclipse.jgit: Repository access and algorithms (Eclipse JGit Project)
  • Eclipse Distribution License (New BSD License)
  • Andrey Loskutov
  • Christian Halstrick
  • Dave Borowitz
  • David Pursehouse
  • Gunnar Wagenknecht
  • Jonathan Nieder
  • Jonathan Tan
  • Matthias Sohn
  • Sasa Zivkov
  • Terry Parker
  • Thomas Wolf 
/*
 * Copyright (C) 2010, Sasa Zivkov <sasa.zivkov@sap.com> and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.eclipse.jgit.notes;

import java.io.IOException;

import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectInserter;
import org.eclipse.jgit.lib.ObjectLoader;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.util.io.UnionInputStream;


Default implementation of the NoteMerger. 

If ours and theirs are both non-null, which means they are either both edits
or both adds, then this merger will simply join the content of ours and
theirs (in that order) and return that as the merge result.


If one or ours/theirs is non-null and the other one is null then the non-null
value is returned as the merge result. This means that an edit/delete
conflict is resolved by keeping the edit version.


If both ours and theirs are null then the result of the merge is also null.

/**
 * Default implementation of the {@link org.eclipse.jgit.notes.NoteMerger}.
 * <p>
 * If ours and theirs are both non-null, which means they are either both edits
 * or both adds, then this merger will simply join the content of ours and
 * theirs (in that order) and return that as the merge result.
 * <p>
 * If one or ours/theirs is non-null and the other one is null then the non-null
 * value is returned as the merge result. This means that an edit/delete
 * conflict is resolved by keeping the edit version.
 * <p>
 * If both ours and theirs are null then the result of the merge is also null.
 */
public class DefaultNoteMerger implements NoteMerger {

	
{@inheritDoc} 
/** {@inheritDoc} */
	@Override
	public Note merge(Note base, Note ours, Note theirs, ObjectReader reader,
			ObjectInserter inserter) throws IOException {
		if (ours == null)
			return theirs;

		if (theirs == null)
			return ours;

		if (ours.getData().equals(theirs.getData()))
			return ours;

		ObjectLoader lo = reader.open(ours.getData());
		ObjectLoader lt = reader.open(theirs.getData());
		try (UnionInputStream union = new UnionInputStream(lo.openStream(),
				lt.openStream())) {
			ObjectId noteData = inserter.insert(Constants.OBJ_BLOB,
					lo.getSize() + lt.getSize(), union);
			return new Note(ours, noteData);
		}
	}
}