blob: 9ac6ca186e3b958b9dd378c7fd144ace729843ad (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/* Copyright 2015 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
package org.brotli.dec;
import static org.brotli.dec.RunningState.BLOCK_START;
import static org.brotli.dec.RunningState.UNINITIALIZED;
import java.io.InputStream;
final class State {
RunningState runningState = UNINITIALIZED;
RunningState nextRunningState;
final BitReader br = new BitReader();
byte[] ringBuffer;
final int[] blockTypeTrees = new int[3 * Huffman.HUFFMAN_MAX_TABLE_SIZE];
final int[] blockLenTrees = new int[3 * Huffman.HUFFMAN_MAX_TABLE_SIZE];
// Current meta-block header information.
int metaBlockLength;
boolean inputEnd;
boolean isUncompressed;
boolean isMetadata;
final HuffmanTreeGroup hGroup0 = new HuffmanTreeGroup();
final HuffmanTreeGroup hGroup1 = new HuffmanTreeGroup();
final HuffmanTreeGroup hGroup2 = new HuffmanTreeGroup();
final int[] blockLength = new int[3];
final int[] numBlockTypes = new int[3];
final int[] blockTypeRb = new int[6];
final int[] distRb = {16, 15, 11, 4};
int pos = 0;
int maxDistance = 0;
int distRbIdx = 0;
boolean trivialLiteralContext = false;
int literalTreeIndex = 0;
int literalTree;
int j;
int insertLength;
byte[] contextModes;
byte[] contextMap;
int contextMapSlice;
int distContextMapSlice;
int contextLookupOffset1;
int contextLookupOffset2;
int treeCommandOffset;
int distanceCode;
byte[] distContextMap;
int numDirectDistanceCodes;
int distancePostfixMask;
int distancePostfixBits;
int distance;
int copyLength;
int copyDst;
int maxBackwardDistance;
int maxRingBufferSize;
int ringBufferSize = 0;
long expectedTotalSize = 0;
byte[] customDictionary = new byte[0];
int bytesToIgnore = 0;
int outputOffset;
int outputLength;
int outputUsed;
int bytesWritten;
int bytesToWrite;
byte[] output;
// TODO: Update to current spec.
private static int decodeWindowBits(BitReader br) {
if (BitReader.readBits(br, 1) == 0) {
return 16;
}
int n = BitReader.readBits(br, 3);
if (n != 0) {
return 17 + n;
}
n = BitReader.readBits(br, 3);
if (n != 0) {
return 8 + n;
}
return 17;
}
/**
* Associate input with decoder state.
*
* @param state uninitialized state without associated input
* @param input compressed data source
*/
static void setInput(State state, InputStream input) {
if (state.runningState != UNINITIALIZED) {
throw new IllegalStateException("State is MUST be uninitialized");
}
BitReader.init(state.br, input);
int windowBits = decodeWindowBits(state.br);
if (windowBits == 9) { /* Reserved case for future expansion. */
throw new BrotliRuntimeException("Invalid 'windowBits' code");
}
state.maxRingBufferSize = 1 << windowBits;
state.maxBackwardDistance = state.maxRingBufferSize - 16;
state.runningState = BLOCK_START;
}
}
|
