/*
* Copyright (C) 2009, Google Inc.
* Copyright (C) 2012, Research In Motion Limited
* 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
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* 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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package org.eclipse.jgit.merge;
import java.io.IOException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.treewalk.AbstractTreeIterator;
import org.eclipse.jgit.treewalk.EmptyTreeIterator;
/** A merge of 2 trees, using a common base ancestor tree. */
public abstract class ThreeWayMerger extends Merger {
private RevTree baseTree;
private ObjectId baseCommitId;
/**
* Create a new merge instance for a repository.
*
* @param local
* the repository this merger will read and write data on.
*/
protected ThreeWayMerger(final Repository local) {
super(local);
}
/**
* Create a new merge instance for a repository.
*
* @param local
* the repository this merger will read and write data on.
* @param inCore
* perform the merge in core with no working folder involved
*/
protected ThreeWayMerger(final Repository local, boolean inCore) {
this(local);
}
/**
* Set the common ancestor tree.
*
* @param id
* common base treeish; null to automatically compute the common
* base from the input commits during
* {@link #merge(AnyObjectId...)}.
* @throws IncorrectObjectTypeException
* the object is not a treeish.
* @throws MissingObjectException
* the object does not exist.
* @throws IOException
* the object could not be read.
*/
public void setBase(final AnyObjectId id) throws MissingObjectException,
IncorrectObjectTypeException, IOException {
if (id != null) {
baseTree = walk.parseTree(id);
} else {
baseTree = null;
}
}
@Override
public boolean merge(final AnyObjectId... tips) throws IOException {
if (tips.length != 2)
return false;
return super.merge(tips);
}
@Override
public ObjectId getBaseCommitId() {
return baseCommitId;
}
/**
* Create an iterator to walk the merge base.
*
* @return an iterator over the caller-specified merge base, or the natural
* merge base of the two input commits.
* @throws IOException
*/
protected AbstractTreeIterator mergeBase() throws IOException {
if (baseTree != null)
return openTree(baseTree);
RevCommit baseCommit = (baseCommitId != null) ? walk
.parseCommit(baseCommitId) : getBaseCommit(sourceCommits[0],
sourceCommits[1]);
if (baseCommit == null) {
baseCommitId = null;
return new EmptyTreeIterator();
} else {
baseCommitId = baseCommit.toObjectId();
return openTree(baseCommit.getTree());
}
}
}