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
60 * {@link org.eclipse.jgit.internal.storage.file.LockFile} which is committed on
61 * close(). The stream checks if the hash of the stream content matches the 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 * Constructor for AtomicObjectOutputStream.
75 *
76 * @param path
77 * a {@link java.nio.file.Path} object.
78 * @param id
79 * a {@link org.eclipse.jgit.lfs.lib.AnyLongObjectId} object.
80 * @throws java.io.IOException
81 */
82 public AtomicObjectOutputStream(Path path, AnyLongObjectId id)
83 throws IOException {
84 locked = new LockFile(path.toFile());
85 locked.lock();
86 this.id = id;
87 out = new DigestOutputStream(locked.getOutputStream(),
88 Constants.newMessageDigest());
89 }
90
91 /**
92 * Constructor for AtomicObjectOutputStream.
93 *
94 * @param path
95 * a {@link java.nio.file.Path} object.
96 * @throws java.io.IOException
97 */
98 public AtomicObjectOutputStream(Path path) throws IOException {
99 this(path, null);
100 }
101
102 /**
103 * Get the <code>id</code>.
104 *
105 * @return content hash of the object which was streamed through this
106 * stream. May return {@code null} if called before closing this
107 * stream.
108 */
109 public @Nullable AnyLongObjectId getId() {
110 return id;
111 }
112
113 /** {@inheritDoc} */
114 @Override
115 public void write(int b) throws IOException {
116 out.write(b);
117 }
118
119 /** {@inheritDoc} */
120 @Override
121 public void write(byte[] b) throws IOException {
122 out.write(b);
123 }
124
125 /** {@inheritDoc} */
126 @Override
127 public void write(byte[] b, int off, int len) throws IOException {
128 out.write(b, off, len);
129 }
130
131 /** {@inheritDoc} */
132 @Override
133 public void close() throws IOException {
134 out.close();
135 if (!aborted) {
136 if (id != null) {
137 verifyHash();
138 } else {
139 id = LongObjectId.fromRaw(out.getMessageDigest().digest());
140 }
141 locked.commit();
142 }
143 }
144
145 private void verifyHash() {
146 AnyLongObjectId contentHash = LongObjectId
147 .fromRaw(out.getMessageDigest().digest());
148 if (!contentHash.equals(id)) {
149 abort();
150 throw new CorruptLongObjectException(id, contentHash,
151 MessageFormat.format(LfsText.get().corruptLongObject,
152 contentHash, id));
153 }
154 }
155
156 /**
157 * Aborts the stream. Temporary file will be deleted
158 */
159 public void abort() {
160 locked.unlock();
161 aborted = true;
162 }
163 }