source: other-projects/trunk/7z-ant/src/SevenZip/Compression/LZ/BinTree.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: 9.0 KB
Line 
1// LZ.BinTree
2
3package SevenZip.Compression.LZ;
4import java.io.IOException;
5
6
7public class BinTree extends InWindow
8{
9 int _cyclicBufferPos;
10 int _cyclicBufferSize = 0;
11 int _matchMaxLen;
12
13 int[] _son;
14 int[] _hash;
15
16 int _cutValue = 0xFF;
17 int _hashMask;
18 int _hashSizeSum = 0;
19
20 boolean HASH_ARRAY = true;
21
22 static final int kHash2Size = 1 << 10;
23 static final int kHash3Size = 1 << 16;
24 static final int kBT2HashSize = 1 << 16;
25 static final int kStartMaxLen = 1;
26 static final int kHash3Offset = kHash2Size;
27 static final int kEmptyHashValue = 0;
28 static final int kMaxValForNormalize = (1 << 30) - 1;
29
30 int kNumHashDirectBytes = 0;
31 int kMinMatchCheck = 4;
32 int kFixHashSize = kHash2Size + kHash3Size;
33
34 public void SetType(int numHashBytes)
35 {
36 HASH_ARRAY = (numHashBytes > 2);
37 if (HASH_ARRAY)
38 {
39 kNumHashDirectBytes = 0;
40 kMinMatchCheck = 4;
41 kFixHashSize = kHash2Size + kHash3Size;
42 }
43 else
44 {
45 kNumHashDirectBytes = 2;
46 kMinMatchCheck = 2 + 1;
47 kFixHashSize = 0;
48 }
49 }
50
51
52
53
54 public void Init() throws IOException
55 {
56 super.Init();
57 for (int i = 0; i < _hashSizeSum; i++)
58 _hash[i] = kEmptyHashValue;
59 _cyclicBufferPos = 0;
60 ReduceOffsets(-1);
61 }
62
63 public void MovePos() throws IOException
64 {
65 if (++_cyclicBufferPos >= _cyclicBufferSize)
66 _cyclicBufferPos = 0;
67 super.MovePos();
68 if (_pos == kMaxValForNormalize)
69 Normalize();
70 }
71
72
73
74
75
76
77
78
79 public boolean Create(int historySize, int keepAddBufferBefore,
80 int matchMaxLen, int keepAddBufferAfter)
81 {
82 if (historySize > kMaxValForNormalize - 256)
83 return false;
84 _cutValue = 16 + (matchMaxLen >> 1);
85
86 int windowReservSize = (historySize + keepAddBufferBefore +
87 matchMaxLen + keepAddBufferAfter) / 2 + 256;
88
89 super.Create(historySize + keepAddBufferBefore, matchMaxLen + keepAddBufferAfter, windowReservSize);
90
91 _matchMaxLen = matchMaxLen;
92
93 int cyclicBufferSize = historySize + 1;
94 if (_cyclicBufferSize != cyclicBufferSize)
95 _son = new int[(_cyclicBufferSize = cyclicBufferSize) * 2];
96
97 int hs = kBT2HashSize;
98
99 if (HASH_ARRAY)
100 {
101 hs = historySize - 1;
102 hs |= (hs >> 1);
103 hs |= (hs >> 2);
104 hs |= (hs >> 4);
105 hs |= (hs >> 8);
106 hs >>= 1;
107 hs |= 0xFFFF;
108 if (hs > (1 << 24))
109 hs >>= 1;
110 _hashMask = hs;
111 hs++;
112 hs += kFixHashSize;
113 }
114 if (hs != _hashSizeSum)
115 _hash = new int [_hashSizeSum = hs];
116 return true;
117 }
118 public int GetMatches(int[] distances) throws IOException
119 {
120 int lenLimit;
121 if (_pos + _matchMaxLen <= _streamPos)
122 lenLimit = _matchMaxLen;
123 else
124 {
125 lenLimit = _streamPos - _pos;
126 if (lenLimit < kMinMatchCheck)
127 {
128 MovePos();
129 return 0;
130 }
131 }
132
133 int offset = 0;
134 int matchMinPos = (_pos > _cyclicBufferSize) ? (_pos - _cyclicBufferSize) : 0;
135 int cur = _bufferOffset + _pos;
136 int maxLen = kStartMaxLen; // to avoid items for len < hashSize;
137 int hashValue, hash2Value = 0, hash3Value = 0;
138
139 if (HASH_ARRAY)
140 {
141 int temp = CrcTable[_bufferBase[cur] & 0xFF] ^ (_bufferBase[cur + 1] & 0xFF);
142 hash2Value = temp & (kHash2Size - 1);
143 temp ^= ((int)(_bufferBase[cur + 2] & 0xFF) << 8);
144 hash3Value = temp & (kHash3Size - 1);
145 hashValue = (temp ^ (CrcTable[_bufferBase[cur + 3] & 0xFF] << 5)) & _hashMask;
146 }
147 else
148 hashValue = ((_bufferBase[cur] & 0xFF) ^ ((int)(_bufferBase[cur + 1] & 0xFF) << 8));
149
150 int curMatch = _hash[kFixHashSize + hashValue];
151 if (HASH_ARRAY)
152 {
153 int curMatch2 = _hash[hash2Value];
154 int curMatch3 = _hash[kHash3Offset + hash3Value];
155 _hash[hash2Value] = _pos;
156 _hash[kHash3Offset + hash3Value] = _pos;
157 if (curMatch2 > matchMinPos)
158 if (_bufferBase[_bufferOffset + curMatch2] == _bufferBase[cur])
159 {
160 distances[offset++] = maxLen = 2;
161 distances[offset++] = _pos - curMatch2 - 1;
162 }
163 if (curMatch3 > matchMinPos)
164 if (_bufferBase[_bufferOffset + curMatch3] == _bufferBase[cur])
165 {
166 if (curMatch3 == curMatch2)
167 offset -= 2;
168 distances[offset++] = maxLen = 3;
169 distances[offset++] = _pos - curMatch3 - 1;
170 curMatch2 = curMatch3;
171 }
172 if (offset != 0 && curMatch2 == curMatch)
173 {
174 offset -= 2;
175 maxLen = kStartMaxLen;
176 }
177 }
178
179 _hash[kFixHashSize + hashValue] = _pos;
180
181 int ptr0 = (_cyclicBufferPos << 1) + 1;
182 int ptr1 = (_cyclicBufferPos << 1);
183
184 int len0, len1;
185 len0 = len1 = kNumHashDirectBytes;
186
187 if (kNumHashDirectBytes != 0)
188 {
189 if (curMatch > matchMinPos)
190 {
191 if (_bufferBase[_bufferOffset + curMatch + kNumHashDirectBytes] !=
192 _bufferBase[cur + kNumHashDirectBytes])
193 {
194 distances[offset++] = maxLen = kNumHashDirectBytes;
195 distances[offset++] = _pos - curMatch - 1;
196 }
197 }
198 }
199
200 int count = _cutValue;
201
202 while (true)
203 {
204 if (curMatch <= matchMinPos || count-- == 0)
205 {
206 _son[ptr0] = _son[ptr1] = kEmptyHashValue;
207 break;
208 }
209 int delta = _pos - curMatch;
210 int cyclicPos = ((delta <= _cyclicBufferPos) ?
211 (_cyclicBufferPos - delta) :
212 (_cyclicBufferPos - delta + _cyclicBufferSize)) << 1;
213
214 int pby1 = _bufferOffset + curMatch;
215 int len = Math.min(len0, len1);
216 if (_bufferBase[pby1 + len] == _bufferBase[cur + len])
217 {
218 while(++len != lenLimit)
219 if (_bufferBase[pby1 + len] != _bufferBase[cur + len])
220 break;
221 if (maxLen < len)
222 {
223 distances[offset++] = maxLen = len;
224 distances[offset++] = delta - 1;
225 if (len == lenLimit)
226 {
227 _son[ptr1] = _son[cyclicPos];
228 _son[ptr0] = _son[cyclicPos + 1];
229 break;
230 }
231 }
232 }
233 if ((_bufferBase[pby1 + len] & 0xFF) < (_bufferBase[cur + len] & 0xFF))
234 {
235 _son[ptr1] = curMatch;
236 ptr1 = cyclicPos + 1;
237 curMatch = _son[ptr1];
238 len1 = len;
239 }
240 else
241 {
242 _son[ptr0] = curMatch;
243 ptr0 = cyclicPos;
244 curMatch = _son[ptr0];
245 len0 = len;
246 }
247 }
248 MovePos();
249 return offset;
250 }
251
252 public void Skip(int num) throws IOException
253 {
254 do
255 {
256 int lenLimit;
257 if (_pos + _matchMaxLen <= _streamPos)
258 lenLimit = _matchMaxLen;
259 else
260 {
261 lenLimit = _streamPos - _pos;
262 if (lenLimit < kMinMatchCheck)
263 {
264 MovePos();
265 continue;
266 }
267 }
268
269 int matchMinPos = (_pos > _cyclicBufferSize) ? (_pos - _cyclicBufferSize) : 0;
270 int cur = _bufferOffset + _pos;
271
272 int hashValue;
273
274 if (HASH_ARRAY)
275 {
276 int temp = CrcTable[_bufferBase[cur] & 0xFF] ^ (_bufferBase[cur + 1] & 0xFF);
277 int hash2Value = temp & (kHash2Size - 1);
278 _hash[hash2Value] = _pos;
279 temp ^= ((int)(_bufferBase[cur + 2] & 0xFF) << 8);
280 int hash3Value = temp & (kHash3Size - 1);
281 _hash[kHash3Offset + hash3Value] = _pos;
282 hashValue = (temp ^ (CrcTable[_bufferBase[cur + 3] & 0xFF] << 5)) & _hashMask;
283 }
284 else
285 hashValue = ((_bufferBase[cur] & 0xFF) ^ ((int)(_bufferBase[cur + 1] & 0xFF) << 8));
286
287 int curMatch = _hash[kFixHashSize + hashValue];
288 _hash[kFixHashSize + hashValue] = _pos;
289
290 int ptr0 = (_cyclicBufferPos << 1) + 1;
291 int ptr1 = (_cyclicBufferPos << 1);
292
293 int len0, len1;
294 len0 = len1 = kNumHashDirectBytes;
295
296 int count = _cutValue;
297 while (true)
298 {
299 if (curMatch <= matchMinPos || count-- == 0)
300 {
301 _son[ptr0] = _son[ptr1] = kEmptyHashValue;
302 break;
303 }
304
305 int delta = _pos - curMatch;
306 int cyclicPos = ((delta <= _cyclicBufferPos) ?
307 (_cyclicBufferPos - delta) :
308 (_cyclicBufferPos - delta + _cyclicBufferSize)) << 1;
309
310 int pby1 = _bufferOffset + curMatch;
311 int len = Math.min(len0, len1);
312 if (_bufferBase[pby1 + len] == _bufferBase[cur + len])
313 {
314 while (++len != lenLimit)
315 if (_bufferBase[pby1 + len] != _bufferBase[cur + len])
316 break;
317 if (len == lenLimit)
318 {
319 _son[ptr1] = _son[cyclicPos];
320 _son[ptr0] = _son[cyclicPos + 1];
321 break;
322 }
323 }
324 if ((_bufferBase[pby1 + len] & 0xFF) < (_bufferBase[cur + len] & 0xFF))
325 {
326 _son[ptr1] = curMatch;
327 ptr1 = cyclicPos + 1;
328 curMatch = _son[ptr1];
329 len1 = len;
330 }
331 else
332 {
333 _son[ptr0] = curMatch;
334 ptr0 = cyclicPos;
335 curMatch = _son[ptr0];
336 len0 = len;
337 }
338 }
339 MovePos();
340 }
341 while (--num != 0);
342 }
343
344 void NormalizeLinks(int[] items, int numItems, int subValue)
345 {
346 for (int i = 0; i < numItems; i++)
347 {
348 int value = items[i];
349 if (value <= subValue)
350 value = kEmptyHashValue;
351 else
352 value -= subValue;
353 items[i] = value;
354 }
355 }
356
357 void Normalize()
358 {
359 int subValue = _pos - _cyclicBufferSize;
360 NormalizeLinks(_son, _cyclicBufferSize * 2, subValue);
361 NormalizeLinks(_hash, _hashSizeSum, subValue);
362 ReduceOffsets(subValue);
363 }
364
365 public void SetCutValue(int cutValue) { _cutValue = cutValue; }
366
367 private static final int[] CrcTable = new int[256];
368
369 static
370 {
371 for (int i = 0; i < 256; i++)
372 {
373 int r = i;
374 for (int j = 0; j < 8; j++)
375 if ((r & 1) != 0)
376 r = (r >>> 1) ^ 0xEDB88320;
377 else
378 r >>>= 1;
379 CrcTable[i] = r;
380 }
381 }
382}
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