1 /*
2 * Copyright (C) 2012, Google Inc.
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.internal.storage.file;
45
46 import java.io.BufferedOutputStream;
47 import java.io.DataOutput;
48 import java.io.IOException;
49 import java.io.OutputStream;
50 import java.security.DigestOutputStream;
51 import java.text.MessageFormat;
52
53 import com.googlecode.javaewah.EWAHCompressedBitmap;
54
55 import org.eclipse.jgit.internal.JGitText;
56 import org.eclipse.jgit.internal.storage.file.PackBitmapIndexBuilder.StoredEntry;
57 import org.eclipse.jgit.lib.Constants;
58 import org.eclipse.jgit.util.io.SafeBufferedOutputStream;
59
60 /**
61 * Creates the version 1 pack bitmap index files.
62 *
63 * @see PackBitmapIndexV1
64 */
65 public class PackBitmapIndexWriterV1 {
66 private final DigestOutputStream out;
67 private final DataOutput dataOutput;
68
69 /**
70 * Creates the version 1 pack bitmap index files.
71 *
72 * @param dst
73 * the output stream to which the index will be written.
74 */
75 public PackBitmapIndexWriterV1(final OutputStream dst) {
76 out = new DigestOutputStream(dst instanceof BufferedOutputStream ? dst
77 : new SafeBufferedOutputStream(dst),
78 Constants.newMessageDigest());
79 dataOutput = new SimpleDataOutput(out);
80 }
81
82 /**
83 * Write all object entries to the index stream.
84 * <p>
85 * After writing the stream passed to the factory is flushed but remains
86 * open. Callers are always responsible for closing the output stream.
87 *
88 * @param bitmaps
89 * the index data for the bitmaps
90 * @param packDataChecksum
91 * checksum signature of the entire pack data content. This is
92 * traditionally the last 20 bytes of the pack file's own stream.
93 * @throws IOException
94 * an error occurred while writing to the output stream, or this
95 * index format cannot store the object data supplied.
96 */
97 public void write(PackBitmapIndexBuilder bitmaps, byte[] packDataChecksum)
98 throws IOException {
99 if (bitmaps == null || packDataChecksum.length != 20)
100 throw new IllegalStateException();
101
102 writeHeader(bitmaps.getOptions(), bitmaps.getBitmapCount(),
103 packDataChecksum);
104 writeBody(bitmaps);
105 writeFooter();
106
107 out.flush();
108 }
109
110 private void writeHeader(
111 int options, int bitmapCount, byte[] packDataChecksum)
112 throws IOException {
113 out.write(PackBitmapIndexV1.MAGIC);
114 dataOutput.writeShort(1);
115 dataOutput.writeShort(options);
116 dataOutput.writeInt(bitmapCount);
117 out.write(packDataChecksum);
118 }
119
120 private void writeBody(PackBitmapIndexBuilder bitmaps) throws IOException {
121 writeBitmap(bitmaps.getCommits());
122 writeBitmap(bitmaps.getTrees());
123 writeBitmap(bitmaps.getBlobs());
124 writeBitmap(bitmaps.getTags());
125 writeBitmaps(bitmaps);
126 }
127
128 private void writeBitmap(EWAHCompressedBitmap bitmap) throws IOException {
129 bitmap.serialize(dataOutput);
130 }
131
132 private void writeBitmaps(PackBitmapIndexBuilder bitmaps)
133 throws IOException {
134 int bitmapCount = 0;
135 for (StoredEntry entry : bitmaps.getCompressedBitmaps()) {
136 writeBitmapEntry(entry);
137 bitmapCount++;
138 }
139
140 int expectedBitmapCount = bitmaps.getBitmapCount();
141 if (expectedBitmapCount != bitmapCount)
142 throw new IOException(MessageFormat.format(
143 JGitText.get().expectedGot,
144 String.valueOf(expectedBitmapCount),
145 String.valueOf(bitmapCount)));
146 }
147
148 private void writeBitmapEntry(StoredEntry entry) throws IOException {
149 // Write object, XOR offset, and bitmap
150 dataOutput.writeInt((int) entry.getObjectId());
151 out.write(entry.getXorOffset());
152 out.write(entry.getFlags());
153 writeBitmap(entry.getBitmap());
154 }
155
156 private void writeFooter() throws IOException {
157 out.on(false);
158 out.write(out.getMessageDigest().digest());
159 }
160 }