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1   /*
2    * Copyright (C) 2010, Sasa Zivkov <sasa.zivkov@sap.com>
3    * and other copyright owners as documented in the project's IP log.
4    *
5    * This program and the accompanying materials are made available
6    * under the terms of the Eclipse Distribution License v1.0 which
7    * accompanies this distribution, is reproduced below, and is
8    * available at http://www.eclipse.org/org/documents/edl-v10.php
9    *
10   * All rights reserved.
11   *
12   * Redistribution and use in source and binary forms, with or
13   * without modification, are permitted provided that the following
14   * conditions are met:
15   *
16   * - Redistributions of source code must retain the above copyright
17   *   notice, this list of conditions and the following disclaimer.
18   *
19   * - Redistributions in binary form must reproduce the above
20   *   copyright notice, this list of conditions and the following
21   *   disclaimer in the documentation and/or other materials provided
22   *   with the distribution.
23   *
24   * - Neither the name of the Eclipse Foundation, Inc. nor the
25   *   names of its contributors may be used to endorse or promote
26   *   products derived from this software without specific prior
27   *   written permission.
28   *
29   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42   */
43  
44  package org.eclipse.jgit.notes;
45  
46  import java.io.IOException;
47  
48  import org.eclipse.jgit.lib.Constants;
49  import org.eclipse.jgit.lib.ObjectId;
50  import org.eclipse.jgit.lib.ObjectInserter;
51  import org.eclipse.jgit.lib.ObjectLoader;
52  import org.eclipse.jgit.lib.ObjectReader;
53  import org.eclipse.jgit.util.io.UnionInputStream;
54  
55  /**
56   * Default implementation of the {@link org.eclipse.jgit.notes.NoteMerger}.
57   * <p>
58   * If ours and theirs are both non-null, which means they are either both edits
59   * or both adds, then this merger will simply join the content of ours and
60   * theirs (in that order) and return that as the merge result.
61   * <p>
62   * If one or ours/theirs is non-null and the other one is null then the non-null
63   * value is returned as the merge result. This means that an edit/delete
64   * conflict is resolved by keeping the edit version.
65   * <p>
66   * If both ours and theirs are null then the result of the merge is also null.
67   */
68  public class DefaultNoteMerger implements NoteMerger {
69  
70  	/** {@inheritDoc} */
71  	@Override
72  	public Notehref="../../../../org/eclipse/jgit/notes/Note.html#Note">Notehref="../../../../org/eclipse/jgit/notes/Note.html#Note">Notehref="../../../../org/eclipse/jgit/notes/Note.html#Note">Note merge(Notehref="../../../../org/eclipse/jgit/notes/Note.html#Note">Notehref="../../../../org/eclipse/jgit/notes/Note.html#Note">Note base, Notehref="../../../../org/eclipse/jgit/notes/Note.html#Note">Note ours, Note theirs, ObjectReader reader,
73  			ObjectInserter inserter) throws IOException {
74  		if (ours == null)
75  			return theirs;
76  
77  		if (theirs == null)
78  			return ours;
79  
80  		if (ours.getData().equals(theirs.getData()))
81  			return ours;
82  
83  		ObjectLoader lo = reader.open(ours.getData());
84  		ObjectLoader lt = reader.open(theirs.getData());
85  		try (UnionInputStreamream.html#UnionInputStream">UnionInputStream union = new UnionInputStream(lo.openStream(),
86  				lt.openStream())) {
87  			ObjectId noteData = inserter.insert(Constants.OBJ_BLOB,
88  					lo.getSize() + lt.getSize(), union);
89  			return new Note(ours, noteData);
90  		}
91  	}
92  }