1 /* LzmaDec.c -- LZMA Decoder
2 2015-01-01 : Igor Pavlov : Public domain */
3 
4 #include "Precomp.h"
5 
6 #include "LzmaDec.h"
7 
8 #include <string.h>
9 
10 #define kNumTopBits 24
11 #define kTopValue ((UInt32)1 << kNumTopBits)
12 
13 #define kNumBitModelTotalBits 11
14 #define kBitModelTotal (1 << kNumBitModelTotalBits)
15 #define kNumMoveBits 5
16 
17 #define RC_INIT_SIZE 5
18 
19 #define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); }
20 
21 #define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
22 #define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
23 #define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
24 #define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \
25   { UPDATE_0(p); i = (i + i); A0; } else \
26   { UPDATE_1(p); i = (i + i) + 1; A1; }
27 #define GET_BIT(p, i) GET_BIT2(p, i, ; , ;)
28 
29 #define TREE_GET_BIT(probs, i) { GET_BIT((probs + i), i); }
30 #define TREE_DECODE(probs, limit, i) \
31   { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }
32 
33 /* #define _LZMA_SIZE_OPT */
34 
35 #ifdef _LZMA_SIZE_OPT
36 #define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
37 #else
38 #define TREE_6_DECODE(probs, i) \
39   { i = 1; \
40   TREE_GET_BIT(probs, i); \
41   TREE_GET_BIT(probs, i); \
42   TREE_GET_BIT(probs, i); \
43   TREE_GET_BIT(probs, i); \
44   TREE_GET_BIT(probs, i); \
45   TREE_GET_BIT(probs, i); \
46   i -= 0x40; }
47 #endif
48 
49 #define NORMAL_LITER_DEC GET_BIT(prob + symbol, symbol)
50 #define MATCHED_LITER_DEC \
51   matchByte <<= 1; \
52   bit = (matchByte & offs); \
53   probLit = prob + offs + bit + symbol; \
54   GET_BIT2(probLit, symbol, offs &= ~bit, offs &= bit)
55 
56 #define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_ERROR; range <<= 8; code = (code << 8) | (*buf++); }
57 
58 #define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
59 #define UPDATE_0_CHECK range = bound;
60 #define UPDATE_1_CHECK range -= bound; code -= bound;
61 #define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \
62   { UPDATE_0_CHECK; i = (i + i); A0; } else \
63   { UPDATE_1_CHECK; i = (i + i) + 1; A1; }
64 #define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)
65 #define TREE_DECODE_CHECK(probs, limit, i) \
66   { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }
67 
68 
69 #define kNumPosBitsMax 4
70 #define kNumPosStatesMax (1 << kNumPosBitsMax)
71 
72 #define kLenNumLowBits 3
73 #define kLenNumLowSymbols (1 << kLenNumLowBits)
74 #define kLenNumMidBits 3
75 #define kLenNumMidSymbols (1 << kLenNumMidBits)
76 #define kLenNumHighBits 8
77 #define kLenNumHighSymbols (1 << kLenNumHighBits)
78 
79 #define LenChoice 0
80 #define LenChoice2 (LenChoice + 1)
81 #define LenLow (LenChoice2 + 1)
82 #define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))
83 #define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))
84 #define kNumLenProbs (LenHigh + kLenNumHighSymbols)
85 
86 
87 #define kNumStates 12
88 #define kNumLitStates 7
89 
90 #define kStartPosModelIndex 4
91 #define kEndPosModelIndex 14
92 #define kNumFullDistances (1 << (kEndPosModelIndex >> 1))
93 
94 #define kNumPosSlotBits 6
95 #define kNumLenToPosStates 4
96 
97 #define kNumAlignBits 4
98 #define kAlignTableSize (1 << kNumAlignBits)
99 
100 #define kMatchMinLen 2
101 #define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols + kLenNumMidSymbols + kLenNumHighSymbols)
102 
103 #define IsMatch 0
104 #define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))
105 #define IsRepG0 (IsRep + kNumStates)
106 #define IsRepG1 (IsRepG0 + kNumStates)
107 #define IsRepG2 (IsRepG1 + kNumStates)
108 #define IsRep0Long (IsRepG2 + kNumStates)
109 #define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))
110 #define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
111 #define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)
112 #define LenCoder (Align + kAlignTableSize)
113 #define RepLenCoder (LenCoder + kNumLenProbs)
114 #define Literal (RepLenCoder + kNumLenProbs)
115 
116 #define LZMA_BASE_SIZE 1846
117 #define LZMA_LIT_SIZE 768
118 
119 #define LzmaProps_GetNumProbs(p) ((UInt32)LZMA_BASE_SIZE + (LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))
120 
121 #if Literal != LZMA_BASE_SIZE
122 StopCompilingDueBUG
123 #endif
124 
125 #define LZMA_DIC_MIN (1 << 12)
126 
127 /* First LZMA-symbol is always decoded.
128 And it decodes new LZMA-symbols while (buf < bufLimit), but "buf" is without last normalization
129 Out:
130   Result:
131     SZ_OK - OK
132     SZ_ERROR_DATA - Error
133   p->remainLen:
134     < kMatchSpecLenStart : normal remain
135     = kMatchSpecLenStart : finished
136     = kMatchSpecLenStart + 1 : Flush marker
137     = kMatchSpecLenStart + 2 : State Init Marker
138 */
139 
LzmaDec_DecodeReal(CLzmaDec * p,SizeT limit,const Byte * bufLimit)140 static int MY_FAST_CALL LzmaDec_DecodeReal(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
141 {
142   CLzmaProb *probs = p->probs;
143 
144   unsigned state = p->state;
145   UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];
146   unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;
147   unsigned lpMask = ((unsigned)1 << (p->prop.lp)) - 1;
148   unsigned lc = p->prop.lc;
149 
150   Byte *dic = p->dic;
151   SizeT dicBufSize = p->dicBufSize;
152   SizeT dicPos = p->dicPos;
153 
154   UInt32 processedPos = p->processedPos;
155   UInt32 checkDicSize = p->checkDicSize;
156   unsigned len = 0;
157 
158   const Byte *buf = p->buf;
159   UInt32 range = p->range;
160   UInt32 code = p->code;
161 
162   do
163   {
164     CLzmaProb *prob;
165     UInt32 bound;
166     unsigned ttt;
167     unsigned posState = processedPos & pbMask;
168 
169     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
170     IF_BIT_0(prob)
171     {
172       unsigned symbol;
173       UPDATE_0(prob);
174       prob = probs + Literal;
175       if (checkDicSize != 0 || processedPos != 0)
176         prob += (LZMA_LIT_SIZE * (((processedPos & lpMask) << lc) +
177         (dic[(dicPos == 0 ? dicBufSize : dicPos) - 1] >> (8 - lc))));
178 
179       if (state < kNumLitStates)
180       {
181         state -= (state < 4) ? state : 3;
182         symbol = 1;
183         #ifdef _LZMA_SIZE_OPT
184         do { NORMAL_LITER_DEC } while (symbol < 0x100);
185         #else
186         NORMAL_LITER_DEC
187         NORMAL_LITER_DEC
188         NORMAL_LITER_DEC
189         NORMAL_LITER_DEC
190         NORMAL_LITER_DEC
191         NORMAL_LITER_DEC
192         NORMAL_LITER_DEC
193         NORMAL_LITER_DEC
194         #endif
195       }
196       else
197       {
198         unsigned matchByte = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
199         unsigned offs = 0x100;
200         state -= (state < 10) ? 3 : 6;
201         symbol = 1;
202         #ifdef _LZMA_SIZE_OPT
203         do
204         {
205           unsigned bit;
206           CLzmaProb *probLit;
207           MATCHED_LITER_DEC
208         }
209         while (symbol < 0x100);
210         #else
211         {
212           unsigned bit;
213           CLzmaProb *probLit;
214           MATCHED_LITER_DEC
215           MATCHED_LITER_DEC
216           MATCHED_LITER_DEC
217           MATCHED_LITER_DEC
218           MATCHED_LITER_DEC
219           MATCHED_LITER_DEC
220           MATCHED_LITER_DEC
221           MATCHED_LITER_DEC
222         }
223         #endif
224       }
225       dic[dicPos++] = (Byte)symbol;
226       processedPos++;
227       continue;
228     }
229     else
230     {
231       UPDATE_1(prob);
232       prob = probs + IsRep + state;
233       IF_BIT_0(prob)
234       {
235         UPDATE_0(prob);
236         state += kNumStates;
237         prob = probs + LenCoder;
238       }
239       else
240       {
241         UPDATE_1(prob);
242         if (checkDicSize == 0 && processedPos == 0)
243           return SZ_ERROR_DATA;
244         prob = probs + IsRepG0 + state;
245         IF_BIT_0(prob)
246         {
247           UPDATE_0(prob);
248           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
249           IF_BIT_0(prob)
250           {
251             UPDATE_0(prob);
252             dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
253             dicPos++;
254             processedPos++;
255             state = state < kNumLitStates ? 9 : 11;
256             continue;
257           }
258           UPDATE_1(prob);
259         }
260         else
261         {
262           UInt32 distance;
263           UPDATE_1(prob);
264           prob = probs + IsRepG1 + state;
265           IF_BIT_0(prob)
266           {
267             UPDATE_0(prob);
268             distance = rep1;
269           }
270           else
271           {
272             UPDATE_1(prob);
273             prob = probs + IsRepG2 + state;
274             IF_BIT_0(prob)
275             {
276               UPDATE_0(prob);
277               distance = rep2;
278             }
279             else
280             {
281               UPDATE_1(prob);
282               distance = rep3;
283               rep3 = rep2;
284             }
285             rep2 = rep1;
286           }
287           rep1 = rep0;
288           rep0 = distance;
289         }
290         state = state < kNumLitStates ? 8 : 11;
291         prob = probs + RepLenCoder;
292       }
293       {
294         unsigned limit, offset;
295         CLzmaProb *probLen = prob + LenChoice;
296         IF_BIT_0(probLen)
297         {
298           UPDATE_0(probLen);
299           probLen = prob + LenLow + (posState << kLenNumLowBits);
300           offset = 0;
301           limit = (1 << kLenNumLowBits);
302         }
303         else
304         {
305           UPDATE_1(probLen);
306           probLen = prob + LenChoice2;
307           IF_BIT_0(probLen)
308           {
309             UPDATE_0(probLen);
310             probLen = prob + LenMid + (posState << kLenNumMidBits);
311             offset = kLenNumLowSymbols;
312             limit = (1 << kLenNumMidBits);
313           }
314           else
315           {
316             UPDATE_1(probLen);
317             probLen = prob + LenHigh;
318             offset = kLenNumLowSymbols + kLenNumMidSymbols;
319             limit = (1 << kLenNumHighBits);
320           }
321         }
322         TREE_DECODE(probLen, limit, len);
323         len += offset;
324       }
325 
326       if (state >= kNumStates)
327       {
328         UInt32 distance;
329         prob = probs + PosSlot +
330             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
331         TREE_6_DECODE(prob, distance);
332         if (distance >= kStartPosModelIndex)
333         {
334           unsigned posSlot = (unsigned)distance;
335           int numDirectBits = (int)(((distance >> 1) - 1));
336           distance = (2 | (distance & 1));
337           if (posSlot < kEndPosModelIndex)
338           {
339             distance <<= numDirectBits;
340             prob = probs + SpecPos + distance - posSlot - 1;
341             {
342               UInt32 mask = 1;
343               unsigned i = 1;
344               do
345               {
346                 GET_BIT2(prob + i, i, ; , distance |= mask);
347                 mask <<= 1;
348               }
349               while (--numDirectBits != 0);
350             }
351           }
352           else
353           {
354             numDirectBits -= kNumAlignBits;
355             do
356             {
357               NORMALIZE
358               range >>= 1;
359 
360               {
361                 UInt32 t;
362                 code -= range;
363                 t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */
364                 distance = (distance << 1) + (t + 1);
365                 code += range & t;
366               }
367               /*
368               distance <<= 1;
369               if (code >= range)
370               {
371                 code -= range;
372                 distance |= 1;
373               }
374               */
375             }
376             while (--numDirectBits != 0);
377             prob = probs + Align;
378             distance <<= kNumAlignBits;
379             {
380               unsigned i = 1;
381               GET_BIT2(prob + i, i, ; , distance |= 1);
382               GET_BIT2(prob + i, i, ; , distance |= 2);
383               GET_BIT2(prob + i, i, ; , distance |= 4);
384               GET_BIT2(prob + i, i, ; , distance |= 8);
385             }
386             if (distance == (UInt32)0xFFFFFFFF)
387             {
388               len += kMatchSpecLenStart;
389               state -= kNumStates;
390               break;
391             }
392           }
393         }
394         rep3 = rep2;
395         rep2 = rep1;
396         rep1 = rep0;
397         rep0 = distance + 1;
398         if (checkDicSize == 0)
399         {
400           if (distance >= processedPos)
401             return SZ_ERROR_DATA;
402         }
403         else if (distance >= checkDicSize)
404           return SZ_ERROR_DATA;
405         state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
406       }
407 
408       len += kMatchMinLen;
409 
410       if (limit == dicPos)
411         return SZ_ERROR_DATA;
412       {
413         SizeT rem = limit - dicPos;
414         unsigned curLen = ((rem < len) ? (unsigned)rem : len);
415         SizeT pos = (dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0);
416 
417         processedPos += curLen;
418 
419         len -= curLen;
420         if (pos + curLen <= dicBufSize)
421         {
422           Byte *dest = dic + dicPos;
423           ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;
424           const Byte *lim = dest + curLen;
425           dicPos += curLen;
426           do
427             *(dest) = (Byte)*(dest + src);
428           while (++dest != lim);
429         }
430         else
431         {
432           do
433           {
434             dic[dicPos++] = dic[pos];
435             if (++pos == dicBufSize)
436               pos = 0;
437           }
438           while (--curLen != 0);
439         }
440       }
441     }
442   }
443   while (dicPos < limit && buf < bufLimit);
444   NORMALIZE;
445   p->buf = buf;
446   p->range = range;
447   p->code = code;
448   p->remainLen = len;
449   p->dicPos = dicPos;
450   p->processedPos = processedPos;
451   p->reps[0] = rep0;
452   p->reps[1] = rep1;
453   p->reps[2] = rep2;
454   p->reps[3] = rep3;
455   p->state = state;
456 
457   return SZ_OK;
458 }
459 
LzmaDec_WriteRem(CLzmaDec * p,SizeT limit)460 static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)
461 {
462   if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)
463   {
464     Byte *dic = p->dic;
465     SizeT dicPos = p->dicPos;
466     SizeT dicBufSize = p->dicBufSize;
467     unsigned len = p->remainLen;
468     UInt32 rep0 = p->reps[0];
469     if (limit - dicPos < len)
470       len = (unsigned)(limit - dicPos);
471 
472     if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
473       p->checkDicSize = p->prop.dicSize;
474 
475     p->processedPos += len;
476     p->remainLen -= len;
477     while (len != 0)
478     {
479       len--;
480       dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
481       dicPos++;
482     }
483     p->dicPos = dicPos;
484   }
485 }
486 
LzmaDec_DecodeReal2(CLzmaDec * p,SizeT limit,const Byte * bufLimit)487 static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
488 {
489   do
490   {
491     SizeT limit2 = limit;
492     if (p->checkDicSize == 0)
493     {
494       UInt32 rem = p->prop.dicSize - p->processedPos;
495       if (limit - p->dicPos > rem)
496         limit2 = p->dicPos + rem;
497     }
498     RINOK(LzmaDec_DecodeReal(p, limit2, bufLimit));
499     if (p->processedPos >= p->prop.dicSize)
500       p->checkDicSize = p->prop.dicSize;
501     LzmaDec_WriteRem(p, limit);
502   }
503   while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);
504 
505   if (p->remainLen > kMatchSpecLenStart)
506   {
507     p->remainLen = kMatchSpecLenStart;
508   }
509   return 0;
510 }
511 
512 typedef enum
513 {
514   DUMMY_ERROR, /* unexpected end of input stream */
515   DUMMY_LIT,
516   DUMMY_MATCH,
517   DUMMY_REP
518 } ELzmaDummy;
519 
LzmaDec_TryDummy(const CLzmaDec * p,const Byte * buf,SizeT inSize)520 static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)
521 {
522   UInt32 range = p->range;
523   UInt32 code = p->code;
524   const Byte *bufLimit = buf + inSize;
525   CLzmaProb *probs = p->probs;
526   unsigned state = p->state;
527   ELzmaDummy res;
528 
529   {
530     CLzmaProb *prob;
531     UInt32 bound;
532     unsigned ttt;
533     unsigned posState = (p->processedPos) & ((1 << p->prop.pb) - 1);
534 
535     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
536     IF_BIT_0_CHECK(prob)
537     {
538       UPDATE_0_CHECK
539 
540       /* if (bufLimit - buf >= 7) return DUMMY_LIT; */
541 
542       prob = probs + Literal;
543       if (p->checkDicSize != 0 || p->processedPos != 0)
544         prob += (LZMA_LIT_SIZE *
545           ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +
546           (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));
547 
548       if (state < kNumLitStates)
549       {
550         unsigned symbol = 1;
551         do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);
552       }
553       else
554       {
555         unsigned matchByte = p->dic[p->dicPos - p->reps[0] +
556             ((p->dicPos < p->reps[0]) ? p->dicBufSize : 0)];
557         unsigned offs = 0x100;
558         unsigned symbol = 1;
559         do
560         {
561           unsigned bit;
562           CLzmaProb *probLit;
563           matchByte <<= 1;
564           bit = (matchByte & offs);
565           probLit = prob + offs + bit + symbol;
566           GET_BIT2_CHECK(probLit, symbol, offs &= ~bit, offs &= bit)
567         }
568         while (symbol < 0x100);
569       }
570       res = DUMMY_LIT;
571     }
572     else
573     {
574       unsigned len;
575       UPDATE_1_CHECK;
576 
577       prob = probs + IsRep + state;
578       IF_BIT_0_CHECK(prob)
579       {
580         UPDATE_0_CHECK;
581         state = 0;
582         prob = probs + LenCoder;
583         res = DUMMY_MATCH;
584       }
585       else
586       {
587         UPDATE_1_CHECK;
588         res = DUMMY_REP;
589         prob = probs + IsRepG0 + state;
590         IF_BIT_0_CHECK(prob)
591         {
592           UPDATE_0_CHECK;
593           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
594           IF_BIT_0_CHECK(prob)
595           {
596             UPDATE_0_CHECK;
597             NORMALIZE_CHECK;
598             return DUMMY_REP;
599           }
600           else
601           {
602             UPDATE_1_CHECK;
603           }
604         }
605         else
606         {
607           UPDATE_1_CHECK;
608           prob = probs + IsRepG1 + state;
609           IF_BIT_0_CHECK(prob)
610           {
611             UPDATE_0_CHECK;
612           }
613           else
614           {
615             UPDATE_1_CHECK;
616             prob = probs + IsRepG2 + state;
617             IF_BIT_0_CHECK(prob)
618             {
619               UPDATE_0_CHECK;
620             }
621             else
622             {
623               UPDATE_1_CHECK;
624             }
625           }
626         }
627         state = kNumStates;
628         prob = probs + RepLenCoder;
629       }
630       {
631         unsigned limit, offset;
632         CLzmaProb *probLen = prob + LenChoice;
633         IF_BIT_0_CHECK(probLen)
634         {
635           UPDATE_0_CHECK;
636           probLen = prob + LenLow + (posState << kLenNumLowBits);
637           offset = 0;
638           limit = 1 << kLenNumLowBits;
639         }
640         else
641         {
642           UPDATE_1_CHECK;
643           probLen = prob + LenChoice2;
644           IF_BIT_0_CHECK(probLen)
645           {
646             UPDATE_0_CHECK;
647             probLen = prob + LenMid + (posState << kLenNumMidBits);
648             offset = kLenNumLowSymbols;
649             limit = 1 << kLenNumMidBits;
650           }
651           else
652           {
653             UPDATE_1_CHECK;
654             probLen = prob + LenHigh;
655             offset = kLenNumLowSymbols + kLenNumMidSymbols;
656             limit = 1 << kLenNumHighBits;
657           }
658         }
659         TREE_DECODE_CHECK(probLen, limit, len);
660         len += offset;
661       }
662 
663       if (state < 4)
664       {
665         unsigned posSlot;
666         prob = probs + PosSlot +
667             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) <<
668             kNumPosSlotBits);
669         TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
670         if (posSlot >= kStartPosModelIndex)
671         {
672           int numDirectBits = ((posSlot >> 1) - 1);
673 
674           /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */
675 
676           if (posSlot < kEndPosModelIndex)
677           {
678             prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits) - posSlot - 1;
679           }
680           else
681           {
682             numDirectBits -= kNumAlignBits;
683             do
684             {
685               NORMALIZE_CHECK
686               range >>= 1;
687               code -= range & (((code - range) >> 31) - 1);
688               /* if (code >= range) code -= range; */
689             }
690             while (--numDirectBits != 0);
691             prob = probs + Align;
692             numDirectBits = kNumAlignBits;
693           }
694           {
695             unsigned i = 1;
696             do
697             {
698               GET_BIT_CHECK(prob + i, i);
699             }
700             while (--numDirectBits != 0);
701           }
702         }
703       }
704     }
705   }
706   NORMALIZE_CHECK;
707   return res;
708 }
709 
710 
LzmaDec_InitRc(CLzmaDec * p,const Byte * data)711 static void LzmaDec_InitRc(CLzmaDec *p, const Byte *data)
712 {
713   p->code = ((UInt32)data[1] << 24) | ((UInt32)data[2] << 16) | ((UInt32)data[3] << 8) | ((UInt32)data[4]);
714   p->range = 0xFFFFFFFF;
715   p->needFlush = 0;
716 }
717 
LzmaDec_InitDicAndState(CLzmaDec * p,Bool initDic,Bool initState)718 void LzmaDec_InitDicAndState(CLzmaDec *p, Bool initDic, Bool initState)
719 {
720   p->needFlush = 1;
721   p->remainLen = 0;
722   p->tempBufSize = 0;
723 
724   if (initDic)
725   {
726     p->processedPos = 0;
727     p->checkDicSize = 0;
728     p->needInitState = 1;
729   }
730   if (initState)
731     p->needInitState = 1;
732 }
733 
LzmaDec_Init(CLzmaDec * p)734 void LzmaDec_Init(CLzmaDec *p)
735 {
736   p->dicPos = 0;
737   LzmaDec_InitDicAndState(p, True, True);
738 }
739 
LzmaDec_InitStateReal(CLzmaDec * p)740 static void LzmaDec_InitStateReal(CLzmaDec *p)
741 {
742   UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (p->prop.lc + p->prop.lp));
743   UInt32 i;
744   CLzmaProb *probs = p->probs;
745   for (i = 0; i < numProbs; i++)
746     probs[i] = kBitModelTotal >> 1;
747   p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
748   p->state = 0;
749   p->needInitState = 0;
750 }
751 
LzmaDec_DecodeToDic(CLzmaDec * p,SizeT dicLimit,const Byte * src,SizeT * srcLen,ELzmaFinishMode finishMode,ELzmaStatus * status)752 SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen,
753     ELzmaFinishMode finishMode, ELzmaStatus *status)
754 {
755   SizeT inSize = *srcLen;
756   (*srcLen) = 0;
757   LzmaDec_WriteRem(p, dicLimit);
758 
759   *status = LZMA_STATUS_NOT_SPECIFIED;
760 
761   while (p->remainLen != kMatchSpecLenStart)
762   {
763       int checkEndMarkNow;
764 
765       if (p->needFlush != 0)
766       {
767         for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
768           p->tempBuf[p->tempBufSize++] = *src++;
769         if (p->tempBufSize < RC_INIT_SIZE)
770         {
771           *status = LZMA_STATUS_NEEDS_MORE_INPUT;
772           return SZ_OK;
773         }
774         if (p->tempBuf[0] != 0)
775           return SZ_ERROR_DATA;
776 
777         LzmaDec_InitRc(p, p->tempBuf);
778         p->tempBufSize = 0;
779       }
780 
781       checkEndMarkNow = 0;
782       if (p->dicPos >= dicLimit)
783       {
784         if (p->remainLen == 0 && p->code == 0)
785         {
786           *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
787           return SZ_OK;
788         }
789         if (finishMode == LZMA_FINISH_ANY)
790         {
791           *status = LZMA_STATUS_NOT_FINISHED;
792           return SZ_OK;
793         }
794         if (p->remainLen != 0)
795         {
796           *status = LZMA_STATUS_NOT_FINISHED;
797           return SZ_ERROR_DATA;
798         }
799         checkEndMarkNow = 1;
800       }
801 
802       if (p->needInitState)
803         LzmaDec_InitStateReal(p);
804 
805       if (p->tempBufSize == 0)
806       {
807         SizeT processed;
808         const Byte *bufLimit;
809         if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
810         {
811           int dummyRes = LzmaDec_TryDummy(p, src, inSize);
812           if (dummyRes == DUMMY_ERROR)
813           {
814             memcpy(p->tempBuf, src, inSize);
815             p->tempBufSize = (unsigned)inSize;
816             (*srcLen) += inSize;
817             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
818             return SZ_OK;
819           }
820           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
821           {
822             *status = LZMA_STATUS_NOT_FINISHED;
823             return SZ_ERROR_DATA;
824           }
825           bufLimit = src;
826         }
827         else
828           bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
829         p->buf = src;
830         if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
831           return SZ_ERROR_DATA;
832         processed = (SizeT)(p->buf - src);
833         (*srcLen) += processed;
834         src += processed;
835         inSize -= processed;
836       }
837       else
838       {
839         unsigned rem = p->tempBufSize, lookAhead = 0;
840         while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)
841           p->tempBuf[rem++] = src[lookAhead++];
842         p->tempBufSize = rem;
843         if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
844         {
845           int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, rem);
846           if (dummyRes == DUMMY_ERROR)
847           {
848             (*srcLen) += lookAhead;
849             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
850             return SZ_OK;
851           }
852           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
853           {
854             *status = LZMA_STATUS_NOT_FINISHED;
855             return SZ_ERROR_DATA;
856           }
857         }
858         p->buf = p->tempBuf;
859         if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
860           return SZ_ERROR_DATA;
861         lookAhead -= (rem - (unsigned)(p->buf - p->tempBuf));
862         (*srcLen) += lookAhead;
863         src += lookAhead;
864         inSize -= lookAhead;
865         p->tempBufSize = 0;
866       }
867   }
868   if (p->code == 0)
869     *status = LZMA_STATUS_FINISHED_WITH_MARK;
870   return (p->code == 0) ? SZ_OK : SZ_ERROR_DATA;
871 }
872 
LzmaDec_DecodeToBuf(CLzmaDec * p,Byte * dest,SizeT * destLen,const Byte * src,SizeT * srcLen,ELzmaFinishMode finishMode,ELzmaStatus * status)873 SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status)
874 {
875   SizeT outSize = *destLen;
876   SizeT inSize = *srcLen;
877   *srcLen = *destLen = 0;
878   for (;;)
879   {
880     SizeT inSizeCur = inSize, outSizeCur, dicPos;
881     ELzmaFinishMode curFinishMode;
882     SRes res;
883     if (p->dicPos == p->dicBufSize)
884       p->dicPos = 0;
885     dicPos = p->dicPos;
886     if (outSize > p->dicBufSize - dicPos)
887     {
888       outSizeCur = p->dicBufSize;
889       curFinishMode = LZMA_FINISH_ANY;
890     }
891     else
892     {
893       outSizeCur = dicPos + outSize;
894       curFinishMode = finishMode;
895     }
896 
897     res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
898     src += inSizeCur;
899     inSize -= inSizeCur;
900     *srcLen += inSizeCur;
901     outSizeCur = p->dicPos - dicPos;
902     memcpy(dest, p->dic + dicPos, outSizeCur);
903     dest += outSizeCur;
904     outSize -= outSizeCur;
905     *destLen += outSizeCur;
906     if (res != 0)
907       return res;
908     if (outSizeCur == 0 || outSize == 0)
909       return SZ_OK;
910   }
911 }
912 
LzmaDec_FreeProbs(CLzmaDec * p,ISzAlloc * alloc)913 void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc)
914 {
915   alloc->Free(alloc, p->probs);
916   p->probs = 0;
917 }
918 
LzmaDec_FreeDict(CLzmaDec * p,ISzAlloc * alloc)919 static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc)
920 {
921   alloc->Free(alloc, p->dic);
922   p->dic = 0;
923 }
924 
LzmaDec_Free(CLzmaDec * p,ISzAlloc * alloc)925 void LzmaDec_Free(CLzmaDec *p, ISzAlloc *alloc)
926 {
927   LzmaDec_FreeProbs(p, alloc);
928   LzmaDec_FreeDict(p, alloc);
929 }
930 
LzmaProps_Decode(CLzmaProps * p,const Byte * data,unsigned size)931 SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)
932 {
933   UInt32 dicSize;
934   Byte d;
935 
936   if (size < LZMA_PROPS_SIZE)
937     return SZ_ERROR_UNSUPPORTED;
938   else
939     dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);
940 
941   if (dicSize < LZMA_DIC_MIN)
942     dicSize = LZMA_DIC_MIN;
943   p->dicSize = dicSize;
944 
945   d = data[0];
946   if (d >= (9 * 5 * 5))
947     return SZ_ERROR_UNSUPPORTED;
948 
949   p->lc = d % 9;
950   d /= 9;
951   p->pb = d / 5;
952   p->lp = d % 5;
953 
954   return SZ_OK;
955 }
956 
LzmaDec_AllocateProbs2(CLzmaDec * p,const CLzmaProps * propNew,ISzAlloc * alloc)957 static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAlloc *alloc)
958 {
959   UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
960   if (p->probs == 0 || numProbs != p->numProbs)
961   {
962     LzmaDec_FreeProbs(p, alloc);
963     p->probs = (CLzmaProb *)alloc->Alloc(alloc, numProbs * sizeof(CLzmaProb));
964     p->numProbs = numProbs;
965     if (p->probs == 0)
966       return SZ_ERROR_MEM;
967   }
968   return SZ_OK;
969 }
970 
LzmaDec_AllocateProbs(CLzmaDec * p,const Byte * props,unsigned propsSize,ISzAlloc * alloc)971 SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
972 {
973   CLzmaProps propNew;
974   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
975   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
976   p->prop = propNew;
977   return SZ_OK;
978 }
979 
LzmaDec_Allocate(CLzmaDec * p,const Byte * props,unsigned propsSize,ISzAlloc * alloc)980 SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
981 {
982   CLzmaProps propNew;
983   SizeT dicBufSize;
984   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
985   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
986   dicBufSize = propNew.dicSize;
987   if (p->dic == 0 || dicBufSize != p->dicBufSize)
988   {
989     LzmaDec_FreeDict(p, alloc);
990     p->dic = (Byte *)alloc->Alloc(alloc, dicBufSize);
991     if (p->dic == 0)
992     {
993       LzmaDec_FreeProbs(p, alloc);
994       return SZ_ERROR_MEM;
995     }
996   }
997   p->dicBufSize = dicBufSize;
998   p->prop = propNew;
999   return SZ_OK;
1000 }
1001 
LzmaDecode(Byte * dest,SizeT * destLen,const Byte * src,SizeT * srcLen,const Byte * propData,unsigned propSize,ELzmaFinishMode finishMode,ELzmaStatus * status,ISzAlloc * alloc)1002 SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
1003     const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
1004     ELzmaStatus *status, ISzAlloc *alloc)
1005 {
1006   CLzmaDec p;
1007   SRes res;
1008   SizeT outSize = *destLen, inSize = *srcLen;
1009   *destLen = *srcLen = 0;
1010   *status = LZMA_STATUS_NOT_SPECIFIED;
1011   if (inSize < RC_INIT_SIZE)
1012     return SZ_ERROR_INPUT_EOF;
1013   LzmaDec_Construct(&p);
1014   RINOK(LzmaDec_AllocateProbs(&p, propData, propSize, alloc));
1015   p.dic = dest;
1016   p.dicBufSize = outSize;
1017   LzmaDec_Init(&p);
1018   *srcLen = inSize;
1019   res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);
1020   *destLen = p.dicPos;
1021   if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
1022     res = SZ_ERROR_INPUT_EOF;
1023   LzmaDec_FreeProbs(&p, alloc);
1024   return res;
1025 }
1026