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1   /*
2    * Copyright (C) 2008-2009, Google Inc.
3    * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
4    * Copyright (C) 2006-2008, Shawn O. Pearce <spearce@spearce.org>
5    * and other copyright owners as documented in the project's IP log.
6    *
7    * This program and the accompanying materials are made available
8    * under the terms of the Eclipse Distribution License v1.0 which
9    * accompanies this distribution, is reproduced below, and is
10   * available at http://www.eclipse.org/org/documents/edl-v10.php
11   *
12   * All rights reserved.
13   *
14   * Redistribution and use in source and binary forms, with or
15   * without modification, are permitted provided that the following
16   * conditions are met:
17   *
18   * - Redistributions of source code must retain the above copyright
19   *   notice, this list of conditions and the following disclaimer.
20   *
21   * - Redistributions in binary form must reproduce the above
22   *   copyright notice, this list of conditions and the following
23   *   disclaimer in the documentation and/or other materials provided
24   *   with the distribution.
25   *
26   * - Neither the name of the Eclipse Foundation, Inc. nor the
27   *   names of its contributors may be used to endorse or promote
28   *   products derived from this software without specific prior
29   *   written permission.
30   *
31   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
32   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
33   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
34   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
36   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
37   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
38   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
39   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
40   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
43   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44   */
45  
46  package org.eclipse.jgit.internal.storage.file;
47  
48  import java.io.IOException;
49  import java.nio.ByteBuffer;
50  import java.util.zip.DataFormatException;
51  import java.util.zip.Inflater;
52  
53  import org.eclipse.jgit.internal.storage.pack.PackOutputStream;
54  
55  /**
56   * A window for accessing git packs using a {@link ByteBuffer} for storage.
57   *
58   * @see ByteWindow
59   */
60  final class ByteBufferWindow extends ByteWindow {
61  	private final ByteBuffer buffer;
62  
63  	ByteBufferWindow(PackFile pack, long o, ByteBuffer b) {
64  		super(pack, o, b.capacity());
65  		buffer = b;
66  	}
67  
68  	/** {@inheritDoc} */
69  	@Override
70  	protected int copy(int p, byte[] b, int o, int n) {
71  		final ByteBuffer s = buffer.slice();
72  		s.position(p);
73  		n = Math.min(s.remaining(), n);
74  		s.get(b, o, n);
75  		return n;
76  	}
77  
78  	@Override
79  	void write(PackOutputStream out, long pos, int cnt)
80  			throws IOException {
81  		final ByteBuffer s = buffer.slice();
82  		s.position((int) (pos - start));
83  
84  		while (0 < cnt) {
85  			byte[] buf = out.getCopyBuffer();
86  			int n = Math.min(cnt, buf.length);
87  			s.get(buf, 0, n);
88  			out.write(buf, 0, n);
89  			cnt -= n;
90  		}
91  	}
92  
93  	/** {@inheritDoc} */
94  	@Override
95  	protected int setInput(int pos, Inflater inf)
96  			throws DataFormatException {
97  		final ByteBuffer s = buffer.slice();
98  		s.position(pos);
99  		final byte[] tmp = new byte[Math.min(s.remaining(), 512)];
100 		s.get(tmp, 0, tmp.length);
101 		inf.setInput(tmp, 0, tmp.length);
102 		return tmp.length;
103 	}
104 }