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comparison src/org/tmatesoft/hg/internal/RevlogCompressor.java @ 530:0f6fa88e2162

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Towards commit command: refactor clone, extract pieces to reuse. Describe a defect discovered when bundle has few patches with 0,0 parents
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Wed, 23 Jan 2013 17:46:12 +0100
parents
children 243202f1bda5
comparison
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529:95bdcf75e71e 530:0f6fa88e2162
1 /*
2 * Copyright (c) 2013 TMate Software Ltd
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * For information on how to redistribute this software under
14 * the terms of a license other than GNU General Public License
15 * contact TMate Software at support@hg4j.com
16 */
17 package org.tmatesoft.hg.internal;
18
19 import java.io.IOException;
20 import java.io.OutputStream;
21 import java.util.zip.Deflater;
22 import java.util.zip.DeflaterOutputStream;
23
24 /**
25 *
26 * @author Artem Tikhomirov
27 * @author TMate Software Ltd.
28 */
29 public class RevlogCompressor {
30 private final Deflater zip;
31 private byte[] sourceData;
32 private int compressedLenEstimate;
33
34 public RevlogCompressor() {
35 zip = new Deflater();
36 }
37
38 public void reset(byte[] source) {
39 sourceData = source;
40 compressedLenEstimate = -1;
41 }
42
43 public int writeCompressedData(OutputStream out) throws IOException {
44 zip.reset();
45 DeflaterOutputStream dos = new DeflaterOutputStream(out, zip, Math.min(2048, sourceData.length));
46 dos.write(sourceData);
47 dos.finish();
48 return zip.getTotalOut();
49 }
50
51 public int getCompressedLengthEstimate() {
52 if (compressedLenEstimate != -1) {
53 return compressedLenEstimate;
54 }
55 zip.reset();
56 int rv = 0;
57 // from DeflaterOutputStream:
58 byte[] buffer = new byte[Math.min(2048, sourceData.length)];
59 for (int i = 0, stride = buffer.length; i < sourceData.length; i+= stride) {
60 zip.setInput(sourceData, i, Math.min(stride, sourceData.length - i));
61 while (!zip.needsInput()) {
62 rv += zip.deflate(buffer, 0, buffer.length);
63 }
64 }
65 zip.finish();
66 while (!zip.finished()) {
67 rv += zip.deflate(buffer, 0, buffer.length);
68 }
69 return compressedLenEstimate = rv;
70 }
71 }