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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
|
package SevenZip.Compression.LZMA;
import SevenZip.Compression.RangeCoder.BitTreeDecoder;
import SevenZip.Compression.LZMA.Base;
import SevenZip.Compression.LZ.OutWindow;
import java.io.IOException;
public class Decoder
{
class LenDecoder
{
short[] m_Choice = new short[2];
BitTreeDecoder[] m_LowCoder = new BitTreeDecoder[Base.kNumPosStatesMax];
BitTreeDecoder[] m_MidCoder = new BitTreeDecoder[Base.kNumPosStatesMax];
BitTreeDecoder m_HighCoder = new BitTreeDecoder(Base.kNumHighLenBits);
int m_NumPosStates = 0;
public void Create(int numPosStates)
{
for (; m_NumPosStates < numPosStates; m_NumPosStates++)
{
m_LowCoder[m_NumPosStates] = new BitTreeDecoder(Base.kNumLowLenBits);
m_MidCoder[m_NumPosStates] = new BitTreeDecoder(Base.kNumMidLenBits);
}
}
public void Init()
{
SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_Choice);
for (int posState = 0; posState < m_NumPosStates; posState++)
{
m_LowCoder[posState].Init();
m_MidCoder[posState].Init();
}
m_HighCoder.Init();
}
public int Decode(SevenZip.Compression.RangeCoder.Decoder rangeDecoder, int posState) throws IOException
{
if (rangeDecoder.DecodeBit(m_Choice, 0) == 0)
return m_LowCoder[posState].Decode(rangeDecoder);
int symbol = Base.kNumLowLenSymbols;
if (rangeDecoder.DecodeBit(m_Choice, 1) == 0)
symbol += m_MidCoder[posState].Decode(rangeDecoder);
else
symbol += Base.kNumMidLenSymbols + m_HighCoder.Decode(rangeDecoder);
return symbol;
}
}
class LiteralDecoder
{
class Decoder2
{
short[] m_Decoders = new short[0x300];
public void Init()
{
SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_Decoders);
}
public byte DecodeNormal(SevenZip.Compression.RangeCoder.Decoder rangeDecoder) throws IOException
{
int symbol = 1;
do
symbol = (symbol << 1) | rangeDecoder.DecodeBit(m_Decoders, symbol);
while (symbol < 0x100);
return (byte)symbol;
}
public byte DecodeWithMatchByte(SevenZip.Compression.RangeCoder.Decoder rangeDecoder, byte matchByte) throws IOException
{
int symbol = 1;
do
{
int matchBit = (matchByte >> 7) & 1;
matchByte <<= 1;
int bit = rangeDecoder.DecodeBit(m_Decoders, ((1 + matchBit) << 8) + symbol);
symbol = (symbol << 1) | bit;
if (matchBit != bit)
{
while (symbol < 0x100)
symbol = (symbol << 1) | rangeDecoder.DecodeBit(m_Decoders, symbol);
break;
}
}
while (symbol < 0x100);
return (byte)symbol;
}
}
Decoder2[] m_Coders;
int m_NumPrevBits;
int m_NumPosBits;
int m_PosMask;
public void Create(int numPosBits, int numPrevBits)
{
if (m_Coders != null && m_NumPrevBits == numPrevBits && m_NumPosBits == numPosBits)
return;
m_NumPosBits = numPosBits;
m_PosMask = (1 << numPosBits) - 1;
m_NumPrevBits = numPrevBits;
int numStates = 1 << (m_NumPrevBits + m_NumPosBits);
m_Coders = new Decoder2[numStates];
for (int i = 0; i < numStates; i++)
m_Coders[i] = new Decoder2();
}
public void Init()
{
int numStates = 1 << (m_NumPrevBits + m_NumPosBits);
for (int i = 0; i < numStates; i++)
m_Coders[i].Init();
}
Decoder2 GetDecoder(int pos, byte prevByte)
{
return m_Coders[((pos & m_PosMask) << m_NumPrevBits) + ((prevByte & 0xFF) >>> (8 - m_NumPrevBits))];
}
}
OutWindow m_OutWindow = new OutWindow();
SevenZip.Compression.RangeCoder.Decoder m_RangeDecoder = new SevenZip.Compression.RangeCoder.Decoder();
short[] m_IsMatchDecoders = new short[Base.kNumStates << Base.kNumPosStatesBitsMax];
short[] m_IsRepDecoders = new short[Base.kNumStates];
short[] m_IsRepG0Decoders = new short[Base.kNumStates];
short[] m_IsRepG1Decoders = new short[Base.kNumStates];
short[] m_IsRepG2Decoders = new short[Base.kNumStates];
short[] m_IsRep0LongDecoders = new short[Base.kNumStates << Base.kNumPosStatesBitsMax];
BitTreeDecoder[] m_PosSlotDecoder = new BitTreeDecoder[Base.kNumLenToPosStates];
short[] m_PosDecoders = new short[Base.kNumFullDistances - Base.kEndPosModelIndex];
BitTreeDecoder m_PosAlignDecoder = new BitTreeDecoder(Base.kNumAlignBits);
LenDecoder m_LenDecoder = new LenDecoder();
LenDecoder m_RepLenDecoder = new LenDecoder();
LiteralDecoder m_LiteralDecoder = new LiteralDecoder();
int m_DictionarySize = -1;
int m_DictionarySizeCheck = -1;
int m_PosStateMask;
public Decoder()
{
for (int i = 0; i < Base.kNumLenToPosStates; i++)
m_PosSlotDecoder[i] = new BitTreeDecoder(Base.kNumPosSlotBits);
}
boolean SetDictionarySize(int dictionarySize)
{
if (dictionarySize < 0)
return false;
if (m_DictionarySize != dictionarySize)
{
m_DictionarySize = dictionarySize;
m_DictionarySizeCheck = Math.max(m_DictionarySize, 1);
m_OutWindow.Create(Math.max(m_DictionarySizeCheck, (1 << 12)));
}
return true;
}
boolean SetLcLpPb(int lc, int lp, int pb)
{
if (lc > Base.kNumLitContextBitsMax || lp > 4 || pb > Base.kNumPosStatesBitsMax)
return false;
m_LiteralDecoder.Create(lp, lc);
int numPosStates = 1 << pb;
m_LenDecoder.Create(numPosStates);
m_RepLenDecoder.Create(numPosStates);
m_PosStateMask = numPosStates - 1;
return true;
}
void Init() throws IOException
{
m_OutWindow.Init(false);
SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsMatchDecoders);
SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRep0LongDecoders);
SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRepDecoders);
SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRepG0Decoders);
SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRepG1Decoders);
SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRepG2Decoders);
SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_PosDecoders);
m_LiteralDecoder.Init();
int i;
for (i = 0; i < Base.kNumLenToPosStates; i++)
m_PosSlotDecoder[i].Init();
m_LenDecoder.Init();
m_RepLenDecoder.Init();
m_PosAlignDecoder.Init();
m_RangeDecoder.Init();
}
public boolean Code(java.io.InputStream inStream, java.io.OutputStream outStream,
long outSize) throws IOException
{
m_RangeDecoder.SetStream(inStream);
m_OutWindow.SetStream(outStream);
Init();
int state = Base.StateInit();
int rep0 = 0, rep1 = 0, rep2 = 0, rep3 = 0;
long nowPos64 = 0;
byte prevByte = 0;
while (outSize < 0 || nowPos64 < outSize)
{
int posState = (int)nowPos64 & m_PosStateMask;
if (m_RangeDecoder.DecodeBit(m_IsMatchDecoders, (state << Base.kNumPosStatesBitsMax) + posState) == 0)
{
LiteralDecoder.Decoder2 decoder2 = m_LiteralDecoder.GetDecoder((int)nowPos64, prevByte);
if (!Base.StateIsCharState(state))
prevByte = decoder2.DecodeWithMatchByte(m_RangeDecoder, m_OutWindow.GetByte(rep0));
else
prevByte = decoder2.DecodeNormal(m_RangeDecoder);
m_OutWindow.PutByte(prevByte);
state = Base.StateUpdateChar(state);
nowPos64++;
}
else
{
int len;
if (m_RangeDecoder.DecodeBit(m_IsRepDecoders, state) == 1)
{
len = 0;
if (m_RangeDecoder.DecodeBit(m_IsRepG0Decoders, state) == 0)
{
if (m_RangeDecoder.DecodeBit(m_IsRep0LongDecoders, (state << Base.kNumPosStatesBitsMax) + posState) == 0)
{
state = Base.StateUpdateShortRep(state);
len = 1;
}
}
else
{
int distance;
if (m_RangeDecoder.DecodeBit(m_IsRepG1Decoders, state) == 0)
distance = rep1;
else
{
if (m_RangeDecoder.DecodeBit(m_IsRepG2Decoders, state) == 0)
distance = rep2;
else
{
distance = rep3;
rep3 = rep2;
}
rep2 = rep1;
}
rep1 = rep0;
rep0 = distance;
}
if (len == 0)
{
len = m_RepLenDecoder.Decode(m_RangeDecoder, posState) + Base.kMatchMinLen;
state = Base.StateUpdateRep(state);
}
}
else
{
rep3 = rep2;
rep2 = rep1;
rep1 = rep0;
len = Base.kMatchMinLen + m_LenDecoder.Decode(m_RangeDecoder, posState);
state = Base.StateUpdateMatch(state);
int posSlot = m_PosSlotDecoder[Base.GetLenToPosState(len)].Decode(m_RangeDecoder);
if (posSlot >= Base.kStartPosModelIndex)
{
int numDirectBits = (posSlot >> 1) - 1;
rep0 = ((2 | (posSlot & 1)) << numDirectBits);
if (posSlot < Base.kEndPosModelIndex)
rep0 += BitTreeDecoder.ReverseDecode(m_PosDecoders,
rep0 - posSlot - 1, m_RangeDecoder, numDirectBits);
else
{
rep0 += (m_RangeDecoder.DecodeDirectBits(
numDirectBits - Base.kNumAlignBits) << Base.kNumAlignBits);
rep0 += m_PosAlignDecoder.ReverseDecode(m_RangeDecoder);
if (rep0 < 0)
{
if (rep0 == -1)
break;
return false;
}
}
}
else
rep0 = posSlot;
}
if (rep0 >= nowPos64 || rep0 >= m_DictionarySizeCheck)
{
// m_OutWindow.Flush();
return false;
}
m_OutWindow.CopyBlock(rep0, len);
nowPos64 += len;
prevByte = m_OutWindow.GetByte(0);
}
}
m_OutWindow.Flush();
m_OutWindow.ReleaseStream();
m_RangeDecoder.ReleaseStream();
return true;
}
public boolean SetDecoderProperties(byte[] properties)
{
if (properties.length < 5)
return false;
int val = properties[0] & 0xFF;
int lc = val % 9;
int remainder = val / 9;
int lp = remainder % 5;
int pb = remainder / 5;
int dictionarySize = 0;
for (int i = 0; i < 4; i++)
dictionarySize += ((int)(properties[1 + i]) & 0xFF) << (i * 8);
if (!SetLcLpPb(lc, lp, pb))
return false;
return SetDictionarySize(dictionarySize);
}
}
|
