1 /*
2 * Copyright (C) 2015, Matthias Sohn <matthias.sohn@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 package org.eclipse.jgit.lfs.internal;
44
45 import java.io.IOException;
46 import java.io.OutputStream;
47 import java.nio.file.Path;
48 import java.security.DigestOutputStream;
49 import java.text.MessageFormat;
50
51 import org.eclipse.jgit.annotations.Nullable;
52 import org.eclipse.jgit.internal.storage.file.LockFile;
53 import org.eclipse.jgit.lfs.errors.CorruptLongObjectException;
54 import org.eclipse.jgit.lfs.lib.AnyLongObjectId;
55 import org.eclipse.jgit.lfs.lib.Constants;
56 import org.eclipse.jgit.lfs.lib.LongObjectId;
57
58 /**
59 * Output stream writing content to a {@link LockFile} which is committed on
60 * close(). The stream checks if the hash of the stream content matches the
61 * id.
62 */
63 public class AtomicObjectOutputStream extends OutputStream {
64
65 private LockFile locked;
66
67 private DigestOutputStream out;
68
69 private boolean aborted;
70
71 private AnyLongObjectId id;
72
73 /**
74 * @param path
75 * @param id
76 * @throws IOException
77 */
78 public AtomicObjectOutputStream(Path path, AnyLongObjectId id)
79 throws IOException {
80 locked = new LockFile(path.toFile());
81 locked.lock();
82 this.id = id;
83 out = new DigestOutputStream(locked.getOutputStream(),
84 Constants.newMessageDigest());
85 }
86
87 /**
88 * @param path
89 * @throws IOException
90 */
91 public AtomicObjectOutputStream(Path path) throws IOException {
92 this(path, null);
93 }
94
95 /**
96 * @return content hash of the object which was streamed through this
97 * stream. May return {@code null} if called before closing this stream.
98 */
99 public @Nullable AnyLongObjectId getId() {
100 return id;
101 }
102
103 @Override
104 public void write(int b) throws IOException {
105 out.write(b);
106 }
107
108 @Override
109 public void write(byte[] b) throws IOException {
110 out.write(b);
111 }
112
113 @Override
114 public void write(byte[] b, int off, int len) throws IOException {
115 out.write(b, off, len);
116 }
117
118 @Override
119 public void close() throws IOException {
120 out.close();
121 if (!aborted) {
122 if (id != null) {
123 verifyHash();
124 } else {
125 id = LongObjectId.fromRaw(out.getMessageDigest().digest());
126 }
127 locked.commit();
128 }
129 }
130
131 private void verifyHash() {
132 AnyLongObjectId contentHash = LongObjectId
133 .fromRaw(out.getMessageDigest().digest());
134 if (!contentHash.equals(id)) {
135 abort();
136 throw new CorruptLongObjectException(id, contentHash,
137 MessageFormat.format(LfsText.get().corruptLongObject,
138 contentHash, id));
139 }
140 }
141
142 /**
143 * Aborts the stream. Temporary file will be deleted
144 */
145 public void abort() {
146 locked.unlock();
147 aborted = true;
148 }
149 }