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1   /*
2    * Copyright (C) 2010, 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.dfs;
45  
46  import java.io.BufferedInputStream;
47  import java.io.IOException;
48  import java.io.InputStream;
49  import java.util.zip.InflaterInputStream;
50  
51  import org.eclipse.jgit.errors.LargeObjectException;
52  import org.eclipse.jgit.errors.MissingObjectException;
53  import org.eclipse.jgit.lib.ObjectId;
54  import org.eclipse.jgit.lib.ObjectLoader;
55  import org.eclipse.jgit.lib.ObjectStream;
56  
57  final class LargePackedWholeObject extends ObjectLoader {
58  	private final int type;
59  
60  	private final long size;
61  
62  	private final long objectOffset;
63  
64  	private final int headerLength;
65  
66  	private final DfsPackFile pack;
67  
68  	private final DfsObjDatabase db;
69  
70  	LargePackedWholeObject(int type, long size, long objectOffset,
71  			int headerLength, DfsPackFile pack, DfsObjDatabase db) {
72  		this.type = type;
73  		this.size = size;
74  		this.objectOffset = objectOffset;
75  		this.headerLength = headerLength;
76  		this.pack = pack;
77  		this.db = db;
78  	}
79  
80  	/** {@inheritDoc} */
81  	@Override
82  	public int getType() {
83  		return type;
84  	}
85  
86  	/** {@inheritDoc} */
87  	@Override
88  	public long getSize() {
89  		return size;
90  	}
91  
92  	/** {@inheritDoc} */
93  	@Override
94  	public boolean isLarge() {
95  		return true;
96  	}
97  
98  	/** {@inheritDoc} */
99  	@Override
100 	public byte[] getCachedBytes() throws LargeObjectException {
101 		throw new LargeObjectException();
102 	}
103 
104 	/** {@inheritDoc} */
105 	@Override
106 	public ObjectStream openStream() throws MissingObjectException, IOException {
107 		PackInputStream packIn;
108 		// ctx is closed by PackInputStream, or explicitly in the finally block
109 		@SuppressWarnings("resource")
110 		DfsReader ctx = db.newReader();
111 		try {
112 			try {
113 				packIn = new PackInputStream(
114 						pack, objectOffset + headerLength, ctx);
115 				ctx = null; // owned by packIn
116 			} catch (IOException packGone) {
117 				// If the pack file cannot be pinned into the cursor, it
118 				// probably was repacked recently. Go find the object
119 				// again and open the stream from that location instead.
120 				ObjectId obj = pack.getReverseIdx(ctx).findObject(objectOffset);
121 				return ctx.open(obj, type).openStream();
122 			}
123 		} finally {
124 			if (ctx != null) {
125 				ctx.close();
126 			}
127 		}
128 
129 		// Align buffer to inflater size, at a larger than default block.
130 		// This reduces the number of context switches from the
131 		// caller down into the pack stream inflation.
132 		int bufsz = 8192;
133 		InputStream in = new BufferedInputStream(
134 				new InflaterInputStream(packIn, packIn.ctx.inflater(), bufsz),
135 				bufsz);
136 		return new ObjectStream.Filter(type, size, in);
137 	}
138 }