source: other-projects/trunk/7z-ant/src/SevenZip/Compression/LZMA/Decoder.java@ 17387

Last change on this file since 17387 was 17387, checked in by oranfry, 16 years ago

Modified ant task which works with the updated 7zip API
File size: 9.8 KB
Line 
1package SevenZip.Compression.LZMA;
2
3import SevenZip.Compression.RangeCoder.BitTreeDecoder;
4import SevenZip.Compression.LZMA.Base;
5import SevenZip.Compression.LZ.OutWindow;
6import java.io.IOException;
7
8public class Decoder
9{
10 class LenDecoder
11 {
12 short[] m_Choice = new short[2];
13 BitTreeDecoder[] m_LowCoder = new BitTreeDecoder[Base.kNumPosStatesMax];
14 BitTreeDecoder[] m_MidCoder = new BitTreeDecoder[Base.kNumPosStatesMax];
15 BitTreeDecoder m_HighCoder = new BitTreeDecoder(Base.kNumHighLenBits);
16 int m_NumPosStates = 0;
17
18 public void Create(int numPosStates)
19 {
20 for (; m_NumPosStates < numPosStates; m_NumPosStates++)
21 {
22 m_LowCoder[m_NumPosStates] = new BitTreeDecoder(Base.kNumLowLenBits);
23 m_MidCoder[m_NumPosStates] = new BitTreeDecoder(Base.kNumMidLenBits);
24 }
25 }
26
27 public void Init()
28 {
29 SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_Choice);
30 for (int posState = 0; posState < m_NumPosStates; posState++)
31 {
32 m_LowCoder[posState].Init();
33 m_MidCoder[posState].Init();
34 }
35 m_HighCoder.Init();
36 }
37
38 public int Decode(SevenZip.Compression.RangeCoder.Decoder rangeDecoder, int posState) throws IOException
39 {
40 if (rangeDecoder.DecodeBit(m_Choice, 0) == 0)
41 return m_LowCoder[posState].Decode(rangeDecoder);
42 int symbol = Base.kNumLowLenSymbols;
43 if (rangeDecoder.DecodeBit(m_Choice, 1) == 0)
44 symbol += m_MidCoder[posState].Decode(rangeDecoder);
45 else
46 symbol += Base.kNumMidLenSymbols + m_HighCoder.Decode(rangeDecoder);
47 return symbol;
48 }
49 }
50
51 class LiteralDecoder
52 {
53 class Decoder2
54 {
55 short[] m_Decoders = new short[0x300];
56
57 public void Init()
58 {
59 SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_Decoders);
60 }
61
62 public byte DecodeNormal(SevenZip.Compression.RangeCoder.Decoder rangeDecoder) throws IOException
63 {
64 int symbol = 1;
65 do
66 symbol = (symbol << 1) | rangeDecoder.DecodeBit(m_Decoders, symbol);
67 while (symbol < 0x100);
68 return (byte)symbol;
69 }
70
71 public byte DecodeWithMatchByte(SevenZip.Compression.RangeCoder.Decoder rangeDecoder, byte matchByte) throws IOException
72 {
73 int symbol = 1;
74 do
75 {
76 int matchBit = (matchByte >> 7) & 1;
77 matchByte <<= 1;
78 int bit = rangeDecoder.DecodeBit(m_Decoders, ((1 + matchBit) << 8) + symbol);
79 symbol = (symbol << 1) | bit;
80 if (matchBit != bit)
81 {
82 while (symbol < 0x100)
83 symbol = (symbol << 1) | rangeDecoder.DecodeBit(m_Decoders, symbol);
84 break;
85 }
86 }
87 while (symbol < 0x100);
88 return (byte)symbol;
89 }
90 }
91
92 Decoder2[] m_Coders;
93 int m_NumPrevBits;
94 int m_NumPosBits;
95 int m_PosMask;
96
97 public void Create(int numPosBits, int numPrevBits)
98 {
99 if (m_Coders != null && m_NumPrevBits == numPrevBits && m_NumPosBits == numPosBits)
100 return;
101 m_NumPosBits = numPosBits;
102 m_PosMask = (1 << numPosBits) - 1;
103 m_NumPrevBits = numPrevBits;
104 int numStates = 1 << (m_NumPrevBits + m_NumPosBits);
105 m_Coders = new Decoder2[numStates];
106 for (int i = 0; i < numStates; i++)
107 m_Coders[i] = new Decoder2();
108 }
109
110 public void Init()
111 {
112 int numStates = 1 << (m_NumPrevBits + m_NumPosBits);
113 for (int i = 0; i < numStates; i++)
114 m_Coders[i].Init();
115 }
116
117 Decoder2 GetDecoder(int pos, byte prevByte)
118 {
119 return m_Coders[((pos & m_PosMask) << m_NumPrevBits) + ((prevByte & 0xFF) >>> (8 - m_NumPrevBits))];
120 }
121 }
122
123 OutWindow m_OutWindow = new OutWindow();
124 SevenZip.Compression.RangeCoder.Decoder m_RangeDecoder = new SevenZip.Compression.RangeCoder.Decoder();
125
126 short[] m_IsMatchDecoders = new short[Base.kNumStates << Base.kNumPosStatesBitsMax];
127 short[] m_IsRepDecoders = new short[Base.kNumStates];
128 short[] m_IsRepG0Decoders = new short[Base.kNumStates];
129 short[] m_IsRepG1Decoders = new short[Base.kNumStates];
130 short[] m_IsRepG2Decoders = new short[Base.kNumStates];
131 short[] m_IsRep0LongDecoders = new short[Base.kNumStates << Base.kNumPosStatesBitsMax];
132
133 BitTreeDecoder[] m_PosSlotDecoder = new BitTreeDecoder[Base.kNumLenToPosStates];
134 short[] m_PosDecoders = new short[Base.kNumFullDistances - Base.kEndPosModelIndex];
135
136 BitTreeDecoder m_PosAlignDecoder = new BitTreeDecoder(Base.kNumAlignBits);
137
138 LenDecoder m_LenDecoder = new LenDecoder();
139 LenDecoder m_RepLenDecoder = new LenDecoder();
140
141 LiteralDecoder m_LiteralDecoder = new LiteralDecoder();
142
143 int m_DictionarySize = -1;
144 int m_DictionarySizeCheck = -1;
145
146 int m_PosStateMask;
147
148 public Decoder()
149 {
150 for (int i = 0; i < Base.kNumLenToPosStates; i++)
151 m_PosSlotDecoder[i] = new BitTreeDecoder(Base.kNumPosSlotBits);
152 }
153
154 boolean SetDictionarySize(int dictionarySize)
155 {
156 if (dictionarySize < 0)
157 return false;
158 if (m_DictionarySize != dictionarySize)
159 {
160 m_DictionarySize = dictionarySize;
161 m_DictionarySizeCheck = Math.max(m_DictionarySize, 1);
162 m_OutWindow.Create(Math.max(m_DictionarySizeCheck, (1 << 12)));
163 }
164 return true;
165 }
166
167 boolean SetLcLpPb(int lc, int lp, int pb)
168 {
169 if (lc > Base.kNumLitContextBitsMax || lp > 4 || pb > Base.kNumPosStatesBitsMax)
170 return false;
171 m_LiteralDecoder.Create(lp, lc);
172 int numPosStates = 1 << pb;
173 m_LenDecoder.Create(numPosStates);
174 m_RepLenDecoder.Create(numPosStates);
175 m_PosStateMask = numPosStates - 1;
176 return true;
177 }
178
179 void Init() throws IOException
180 {
181 m_OutWindow.Init(false);
182
183 SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsMatchDecoders);
184 SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRep0LongDecoders);
185 SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRepDecoders);
186 SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRepG0Decoders);
187 SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRepG1Decoders);
188 SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_IsRepG2Decoders);
189 SevenZip.Compression.RangeCoder.Decoder.InitBitModels(m_PosDecoders);
190
191 m_LiteralDecoder.Init();
192 int i;
193 for (i = 0; i < Base.kNumLenToPosStates; i++)
194 m_PosSlotDecoder[i].Init();
195 m_LenDecoder.Init();
196 m_RepLenDecoder.Init();
197 m_PosAlignDecoder.Init();
198 m_RangeDecoder.Init();
199 }
200
201 public boolean Code(java.io.InputStream inStream, java.io.OutputStream outStream,
202 long outSize) throws IOException
203 {
204 m_RangeDecoder.SetStream(inStream);
205 m_OutWindow.SetStream(outStream);
206 Init();
207
208 int state = Base.StateInit();
209 int rep0 = 0, rep1 = 0, rep2 = 0, rep3 = 0;
210
211 long nowPos64 = 0;
212 byte prevByte = 0;
213 while (outSize < 0 || nowPos64 < outSize)
214 {
215 int posState = (int)nowPos64 & m_PosStateMask;
216 if (m_RangeDecoder.DecodeBit(m_IsMatchDecoders, (state << Base.kNumPosStatesBitsMax) + posState) == 0)
217 {
218 LiteralDecoder.Decoder2 decoder2 = m_LiteralDecoder.GetDecoder((int)nowPos64, prevByte);
219 if (!Base.StateIsCharState(state))
220 prevByte = decoder2.DecodeWithMatchByte(m_RangeDecoder, m_OutWindow.GetByte(rep0));
221 else
222 prevByte = decoder2.DecodeNormal(m_RangeDecoder);
223 m_OutWindow.PutByte(prevByte);
224 state = Base.StateUpdateChar(state);
225 nowPos64++;
226 }
227 else
228 {
229 int len;
230 if (m_RangeDecoder.DecodeBit(m_IsRepDecoders, state) == 1)
231 {
232 len = 0;
233 if (m_RangeDecoder.DecodeBit(m_IsRepG0Decoders, state) == 0)
234 {
235 if (m_RangeDecoder.DecodeBit(m_IsRep0LongDecoders, (state << Base.kNumPosStatesBitsMax) + posState) == 0)
236 {
237 state = Base.StateUpdateShortRep(state);
238 len = 1;
239 }
240 }
241 else
242 {
243 int distance;
244 if (m_RangeDecoder.DecodeBit(m_IsRepG1Decoders, state) == 0)
245 distance = rep1;
246 else
247 {
248 if (m_RangeDecoder.DecodeBit(m_IsRepG2Decoders, state) == 0)
249 distance = rep2;
250 else
251 {
252 distance = rep3;
253 rep3 = rep2;
254 }
255 rep2 = rep1;
256 }
257 rep1 = rep0;
258 rep0 = distance;
259 }
260 if (len == 0)
261 {
262 len = m_RepLenDecoder.Decode(m_RangeDecoder, posState) + Base.kMatchMinLen;
263 state = Base.StateUpdateRep(state);
264 }
265 }
266 else
267 {
268 rep3 = rep2;
269 rep2 = rep1;
270 rep1 = rep0;
271 len = Base.kMatchMinLen + m_LenDecoder.Decode(m_RangeDecoder, posState);
272 state = Base.StateUpdateMatch(state);
273 int posSlot = m_PosSlotDecoder[Base.GetLenToPosState(len)].Decode(m_RangeDecoder);
274 if (posSlot >= Base.kStartPosModelIndex)
275 {
276 int numDirectBits = (posSlot >> 1) - 1;
277 rep0 = ((2 | (posSlot & 1)) << numDirectBits);
278 if (posSlot < Base.kEndPosModelIndex)
279 rep0 += BitTreeDecoder.ReverseDecode(m_PosDecoders,
280 rep0 - posSlot - 1, m_RangeDecoder, numDirectBits);
281 else
282 {
283 rep0 += (m_RangeDecoder.DecodeDirectBits(
284 numDirectBits - Base.kNumAlignBits) << Base.kNumAlignBits);
285 rep0 += m_PosAlignDecoder.ReverseDecode(m_RangeDecoder);
286 if (rep0 < 0)
287 {
288 if (rep0 == -1)
289 break;
290 return false;
291 }
292 }
293 }
294 else
295 rep0 = posSlot;
296 }
297 if (rep0 >= nowPos64 || rep0 >= m_DictionarySizeCheck)
298 {
299 // m_OutWindow.Flush();
300 return false;
301 }
302 m_OutWindow.CopyBlock(rep0, len);
303 nowPos64 += len;
304 prevByte = m_OutWindow.GetByte(0);
305 }
306 }
307 m_OutWindow.Flush();
308 m_OutWindow.ReleaseStream();
309 m_RangeDecoder.ReleaseStream();
310 return true;
311 }
312
313 public boolean SetDecoderProperties(byte[] properties)
314 {
315 if (properties.length < 5)
316 return false;
317 int val = properties[0] & 0xFF;
318 int lc = val % 9;
319 int remainder = val / 9;
320 int lp = remainder % 5;
321 int pb = remainder / 5;
322 int dictionarySize = 0;
323 for (int i = 0; i < 4; i++)
324 dictionarySize += ((int)(properties[1 + i]) & 0xFF) << (i * 8);
325 if (!SetLcLpPb(lc, lp, pb))
326 return false;
327 return SetDictionarySize(dictionarySize);
328 }
329}
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