1 /*
2 * Copyright (C) 2011, Stefan Lay <stefan.lay@.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 package org.eclipse.jgit.diff;
44
45 import java.io.IOException;
46 import java.io.OutputStream;
47 import java.security.DigestOutputStream;
48 import java.security.MessageDigest;
49
50 import org.eclipse.jgit.lib.Constants;
51 import org.eclipse.jgit.lib.ObjectId;
52 import org.eclipse.jgit.util.io.NullOutputStream;
53
54 /**
55 * A DiffFormatter used to calculate the patch-id of the diff.
56 */
57 public class PatchIdDiffFormatter extends DiffFormatter {
58
59 private final MessageDigest digest;
60
61 /** Initialize a formatter to compute a patch id. */
62 public PatchIdDiffFormatter() {
63 super(new DigestOutputStream(NullOutputStream.INSTANCE,
64 Constants.newMessageDigest()));
65 digest = ((DigestOutputStream) getOutputStream()).getMessageDigest();
66 }
67
68 /**
69 * Should be called after having called one of the format methods
70 *
71 * @return the patch id calculated for the provided diff.
72 */
73 public ObjectId getCalulatedPatchId() {
74 return ObjectId.fromRaw(digest.digest());
75 }
76
77 @Override
78 protected void writeHunkHeader(int aStartLine, int aEndLine,
79 int bStartLine, int bEndLine) throws IOException {
80 // The hunk header is not taken into account for patch id calculation
81 }
82
83 @Override
84 protected void formatIndexLine(OutputStream o, DiffEntry ent)
85 throws IOException {
86 // The index line is not taken into account for patch id calculation
87 }
88 }