/*
* Copyright (C) 2010, Sasa Zivkov <sasa.zivkov@sap.com>
* and other copyright owners as documented in the project's IP log.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Distribution License v1.0 which
* accompanies this distribution, is reproduced below, and is
* available at http://www.eclipse.org/org/documents/edl-v10.php
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* - Neither the name of the Eclipse Foundation, Inc. nor the
* names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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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 {@link 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 {
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());
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);
}
}