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comparison src/org/tmatesoft/hg/internal/DeflaterDataSerializer.java @ 534:243202f1bda5

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Commit: refactor revision creation code from clone command to work separately, fit into existing library structure
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Mon, 04 Feb 2013 18:00:55 +0100
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children 7c0d2ce340b8
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533:e6f72c9829a6 534:243202f1bda5
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.util.zip.Deflater;
21 import java.util.zip.DeflaterOutputStream;
22
23 /**
24 * {@link DeflaterOutputStream} counterpart for {@link DataSerializer} API
25 *
26 * @author Artem Tikhomirov
27 * @author TMate Software Ltd.
28 */
29 class DeflaterDataSerializer extends DataSerializer {
30
31 private static final int AUX_BUFFER_CAPACITY = 5; // room for 5 ints
32
33 private final DataSerializer delegate;
34 private final Deflater deflater;
35 private final byte[] deflateOutBuffer;
36 private final byte[] auxBuffer;
37
38 public DeflaterDataSerializer(DataSerializer delegateSerializer, Deflater def, int bufferSizeHint) {
39 delegate = delegateSerializer;
40 deflater = def;
41 deflateOutBuffer = new byte[bufferSizeHint <= 0 ? 2048 : bufferSizeHint];
42 auxBuffer = new byte[4 * AUX_BUFFER_CAPACITY]; // sizeof(int) * capacity
43 }
44
45 @Override
46 public void writeInt(int... values) throws IOException {
47 for (int i = 0; i < values.length; i+= AUX_BUFFER_CAPACITY) {
48 int idx = 0;
49 for (int j = i, x = Math.min(values.length, i + AUX_BUFFER_CAPACITY); j < x; j++) {
50 int v = values[j];
51 auxBuffer[idx++] = (byte) ((v >>> 24) & 0x0ff);
52 auxBuffer[idx++] = (byte) ((v >>> 16) & 0x0ff);
53 auxBuffer[idx++] = (byte) ((v >>> 8) & 0x0ff);
54 auxBuffer[idx++] = (byte) (v & 0x0ff);
55 }
56 internalWrite(auxBuffer, 0, idx);
57 }
58 }
59
60 @Override
61 public void write(byte[] data, int offset, int length) throws IOException {
62 // @see DeflaterOutputStream#write(byte[], int, int)
63 int stride = deflateOutBuffer.length;
64 for (int i = 0; i < length; i += stride) {
65 internalWrite(data, offset + i, Math.min(stride, length - i));
66 }
67 }
68
69 private void internalWrite(byte[] data, int offset, int length) throws IOException {
70 deflater.setInput(data, offset, length);
71 while (!deflater.needsInput()) {
72 deflate();
73 }
74 }
75
76 @Override
77 public void done() {
78 delegate.done();
79 }
80
81 public void finish() throws IOException {
82 if (!deflater.finished()) {
83 deflater.finish();
84 while (!deflater.finished()) {
85 deflate();
86 }
87 }
88 }
89
90 protected void deflate() throws IOException {
91 int len = deflater.deflate(deflateOutBuffer, 0, deflateOutBuffer.length);
92 if (len > 0) {
93 delegate.write(deflateOutBuffer, 0, len);
94 }
95 }
96 }