release/src-rt/tools/misc/lzma_src/C/LzmaDec.c

   1 /* LzmaDec.c -- LZMA Decoder
   2 2008-11-06 : Igor Pavlov : Public domain */
   3
   4 #include "LzmaDec.h"
   5 #ifndef BCMLZMA
   6 #include <string.h>
   7 #endif
   8
   9 #define kNumTopBits 24
  10 #define kTopValue ((UInt32)1 << kNumTopBits)
  11
  12 #define kNumBitModelTotalBits 11
  13 #define kBitModelTotal (1 << kNumBitModelTotalBits)
  14 #define kNumMoveBits 5
  15
  16 #define RC_INIT_SIZE 5
  17
  18 #define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); }
  19
  20 #define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
  21 #define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
  22 #define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
  23 #define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \
  24   { UPDATE_0(p); i = (i + i); A0; } else \
  25   { UPDATE_1(p); i = (i + i) + 1; A1; }
  26 #define GET_BIT(p, i) GET_BIT2(p, i, ; , ;)
  27
  28 #define TREE_GET_BIT(probs, i) { GET_BIT((probs + i), i); }
  29 #define TREE_DECODE(probs, limit, i) \
  30   { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }
  31
  32 /* #define _LZMA_SIZE_OPT */
  33
  34 #ifdef _LZMA_SIZE_OPT
  35 #define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
  36 #else
  37 #define TREE_6_DECODE(probs, i) \
  38   { i = 1; \
  39   TREE_GET_BIT(probs, i); \
  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   i -= 0x40; }
  46 #endif
  47
  48 #define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_ERROR; range <<= 8; code = (code << 8) | (*buf++); }
  49
  50 #define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
  51 #define UPDATE_0_CHECK range = bound;
  52 #define UPDATE_1_CHECK range -= bound; code -= bound;
  53 #define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \
  54   { UPDATE_0_CHECK; i = (i + i); A0; } else \
  55   { UPDATE_1_CHECK; i = (i + i) + 1; A1; }
  56 #define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)
  57 #define TREE_DECODE_CHECK(probs, limit, i) \
  58   { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }
  59
  60
  61 #define kNumPosBitsMax 4
  62 #define kNumPosStatesMax (1 << kNumPosBitsMax)
  63
  64 #define kLenNumLowBits 3
  65 #define kLenNumLowSymbols (1 << kLenNumLowBits)
  66 #define kLenNumMidBits 3
  67 #define kLenNumMidSymbols (1 << kLenNumMidBits)
  68 #define kLenNumHighBits 8
  69 #define kLenNumHighSymbols (1 << kLenNumHighBits)
  70
  71 #define LenChoice 0
  72 #define LenChoice2 (LenChoice + 1)
  73 #define LenLow (LenChoice2 + 1)
  74 #define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))
  75 #define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))
  76 #define kNumLenProbs (LenHigh + kLenNumHighSymbols)
  77
  78
  79 #define kNumStates 12
  80 #define kNumLitStates 7
  81
  82 #define kStartPosModelIndex 4
  83 #define kEndPosModelIndex 14
  84 #define kNumFullDistances (1 << (kEndPosModelIndex >> 1))
  85
  86 #define kNumPosSlotBits 6
  87 #define kNumLenToPosStates 4
  88
  89 #define kNumAlignBits 4
  90 #define kAlignTableSize (1 << kNumAlignBits)
  91
  92 #define kMatchMinLen 2
  93 #define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols + kLenNumMidSymbols + kLenNumHighSymbols)
  94
  95 #define IsMatch 0
  96 #define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))
  97 #define IsRepG0 (IsRep + kNumStates)
  98 #define IsRepG1 (IsRepG0 + kNumStates)
  99 #define IsRepG2 (IsRepG1 + kNumStates)
 100 #define IsRep0Long (IsRepG2 + kNumStates)
 101 #define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))
 102 #define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
 103 #define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)
 104 #define LenCoder (Align + kAlignTableSize)
 105 #define RepLenCoder (LenCoder + kNumLenProbs)
 106 #define Literal (RepLenCoder + kNumLenProbs)
 107
 108 #define LZMA_BASE_SIZE 1846
 109 #define LZMA_LIT_SIZE 768
 110
 111 #define LzmaProps_GetNumProbs(p) ((UInt32)LZMA_BASE_SIZE + (LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))
 112
 113 #if Literal != LZMA_BASE_SIZE
 114 StopCompilingDueBUG
 115 #endif
 116
 117 static const Byte kLiteralNextStates[kNumStates * 2] =
 118 {
 119   0, 0, 0, 0, 1, 2, 3,  4,  5,  6,  4,  5,
 120   7, 7, 7, 7, 7, 7, 7, 10, 10, 10, 10, 10
 121 };
 122
 123 #define LZMA_DIC_MIN (1 << 12)
 124
 125 /* First LZMA-symbol is always decoded.
 126 And it decodes new LZMA-symbols while (buf < bufLimit), but "buf" is without last normalization
 127 Out:
 128   Result:
 129     SZ_OK - OK
 130     SZ_ERROR_DATA - Error
 131   p->remainLen:
 132     < kMatchSpecLenStart : normal remain
 133     = kMatchSpecLenStart : finished
 134     = kMatchSpecLenStart + 1 : Flush marker
 135     = kMatchSpecLenStart + 2 : State Init Marker
 136 */
 137
 138 static int MY_FAST_CALL LzmaDec_DecodeReal(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
 139 {
 140   CLzmaProb *probs = p->probs;
 141
 142   unsigned state = p->state;
 143   UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];
 144   unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;
 145   unsigned lpMask = ((unsigned)1 << (p->prop.lp)) - 1;
 146   unsigned lc = p->prop.lc;
 147
 148   Byte *dic = p->dic;
 149   SizeT dicBufSize = p->dicBufSize;
 150   SizeT dicPos = p->dicPos;
 151
 152   UInt32 processedPos = p->processedPos;
 153   UInt32 checkDicSize = p->checkDicSize;
 154   unsigned len = 0;
 155
 156   const Byte *buf = p->buf;
 157   UInt32 range = p->range;
 158   UInt32 code = p->code;
 159
 160   do
 161   {
 162     CLzmaProb *prob;
 163     UInt32 bound;
 164     unsigned ttt;
 165     unsigned posState = processedPos & pbMask;
 166
 167     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
 168     IF_BIT_0(prob)
 169     {
 170       unsigned symbol;
 171       UPDATE_0(prob);
 172       prob = probs + Literal;
 173       if (checkDicSize != 0 || processedPos != 0)
 174         prob += (LZMA_LIT_SIZE * (((processedPos & lpMask) << lc) +
 175         (dic[(dicPos == 0 ? dicBufSize : dicPos) - 1] >> (8 - lc))));
 176
 177       if (state < kNumLitStates)
 178       {
 179         symbol = 1;
 180         do { GET_BIT(prob + symbol, symbol) } while (symbol < 0x100);
 181       }
 182       else
 183       {
 184         unsigned matchByte = p->dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 185         unsigned offs = 0x100;
 186         symbol = 1;
 187         do
 188         {
 189           unsigned bit;
 190           CLzmaProb *probLit;
 191           matchByte <<= 1;
 192           bit = (matchByte & offs);
 193           probLit = prob + offs + bit + symbol;
 194           GET_BIT2(probLit, symbol, offs &= ~bit, offs &= bit)
 195         }
 196         while (symbol < 0x100);
 197       }
 198       dic[dicPos++] = (Byte)symbol;
 199       processedPos++;
 200
 201       state = kLiteralNextStates[state];
 202       /* if (state < 4) state = 0; else if (state < 10) state -= 3; else state -= 6; */
 203       continue;
 204     }
 205     else
 206     {
 207       UPDATE_1(prob);
 208       prob = probs + IsRep + state;
 209       IF_BIT_0(prob)
 210       {
 211         UPDATE_0(prob);
 212         state += kNumStates;
 213         prob = probs + LenCoder;
 214       }
 215       else
 216       {
 217         UPDATE_1(prob);
 218         if (checkDicSize == 0 && processedPos == 0)
 219           return SZ_ERROR_DATA;
 220         prob = probs + IsRepG0 + state;
 221         IF_BIT_0(prob)
 222         {
 223           UPDATE_0(prob);
 224           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
 225           IF_BIT_0(prob)
 226           {
 227             UPDATE_0(prob);
 228             dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 229             dicPos++;
 230             processedPos++;
 231             state = state < kNumLitStates ? 9 : 11;
 232             continue;
 233           }
 234           UPDATE_1(prob);
 235         }
 236         else
 237         {
 238           UInt32 distance;
 239           UPDATE_1(prob);
 240           prob = probs + IsRepG1 + state;
 241           IF_BIT_0(prob)
 242           {
 243             UPDATE_0(prob);
 244             distance = rep1;
 245           }
 246           else
 247           {
 248             UPDATE_1(prob);
 249             prob = probs + IsRepG2 + state;
 250             IF_BIT_0(prob)
 251             {
 252               UPDATE_0(prob);
 253               distance = rep2;
 254             }
 255             else
 256             {
 257               UPDATE_1(prob);
 258               distance = rep3;
 259               rep3 = rep2;
 260             }
 261             rep2 = rep1;
 262           }
 263           rep1 = rep0;
 264           rep0 = distance;
 265         }
 266         state = state < kNumLitStates ? 8 : 11;
 267         prob = probs + RepLenCoder;
 268       }
 269       {
 270         unsigned limit, offset;
 271         CLzmaProb *probLen = prob + LenChoice;
 272         IF_BIT_0(probLen)
 273         {
 274           UPDATE_0(probLen);
 275           probLen = prob + LenLow + (posState << kLenNumLowBits);
 276           offset = 0;
 277           limit = (1 << kLenNumLowBits);
 278         }
 279         else
 280         {
 281           UPDATE_1(probLen);
 282           probLen = prob + LenChoice2;
 283           IF_BIT_0(probLen)
 284           {
 285             UPDATE_0(probLen);
 286             probLen = prob + LenMid + (posState << kLenNumMidBits);
 287             offset = kLenNumLowSymbols;
 288             limit = (1 << kLenNumMidBits);
 289           }
 290           else
 291           {
 292             UPDATE_1(probLen);
 293             probLen = prob + LenHigh;
 294             offset = kLenNumLowSymbols + kLenNumMidSymbols;
 295             limit = (1 << kLenNumHighBits);
 296           }
 297         }
 298         TREE_DECODE(probLen, limit, len);
 299         len += offset;
 300       }
 301
 302       if (state >= kNumStates)
 303       {
 304         UInt32 distance;
 305         prob = probs + PosSlot +
 306             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
 307         TREE_6_DECODE(prob, distance);
 308         if (distance >= kStartPosModelIndex)
 309         {
 310           unsigned posSlot = (unsigned)distance;
 311           int numDirectBits = (int)(((distance >> 1) - 1));
 312           distance = (2 | (distance & 1));
 313           if (posSlot < kEndPosModelIndex)
 314           {
 315             distance <<= numDirectBits;
 316             prob = probs + SpecPos + distance - posSlot - 1;
 317             {
 318               UInt32 mask = 1;
 319               unsigned i = 1;
 320               do
 321               {
 322                 GET_BIT2(prob + i, i, ; , distance |= mask);
 323                 mask <<= 1;
 324               }
 325               while (--numDirectBits != 0);
 326             }
 327           }
 328           else
 329           {
 330             numDirectBits -= kNumAlignBits;
 331             do
 332             {
 333               NORMALIZE
 334               range >>= 1;
 335
 336               {
 337                 UInt32 t;
 338                 code -= range;
 339                 t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */
 340                 distance = (distance << 1) + (t + 1);
 341                 code += range & t;
 342               }
 343               /*
 344               distance <<= 1;
 345               if (code >= range)
 346               {
 347                 code -= range;
 348                 distance |= 1;
 349               }
 350               */
 351             }
 352             while (--numDirectBits != 0);
 353             prob = probs + Align;
 354             distance <<= kNumAlignBits;
 355             {
 356               unsigned i = 1;
 357               GET_BIT2(prob + i, i, ; , distance |= 1);
 358               GET_BIT2(prob + i, i, ; , distance |= 2);
 359               GET_BIT2(prob + i, i, ; , distance |= 4);
 360               GET_BIT2(prob + i, i, ; , distance |= 8);
 361             }
 362             if (distance == (UInt32)0xFFFFFFFF)
 363             {
 364               len += kMatchSpecLenStart;
 365               state -= kNumStates;
 366               break;
 367             }
 368           }
 369         }
 370         rep3 = rep2;
 371         rep2 = rep1;
 372         rep1 = rep0;
 373         rep0 = distance + 1;
 374         if (checkDicSize == 0)
 375         {
 376           if (distance >= processedPos)
 377             return SZ_ERROR_DATA;
 378         }
 379         else if (distance >= checkDicSize)
 380           return SZ_ERROR_DATA;
 381         state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
 382         /* state = kLiteralNextStates[state]; */
 383       }
 384
 385       len += kMatchMinLen;
 386
 387       if (limit == dicPos)
 388         return SZ_ERROR_DATA;
 389       {
 390         SizeT rem = limit - dicPos;
 391         unsigned curLen = ((rem < len) ? (unsigned)rem : len);
 392         SizeT pos = (dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0);
 393
 394         processedPos += curLen;
 395
 396         len -= curLen;
 397         if (pos + curLen <= dicBufSize)
 398         {
 399           Byte *dest = dic + dicPos;
 400           int src = (int)pos - (int)dicPos;
 401           const Byte *lim = dest + curLen;
 402           dicPos += curLen;
 403           do
 404             *(dest) = (Byte)*(dest + src);
 405           while (++dest != lim);
 406         }
 407         else
 408         {
 409           do
 410           {
 411             dic[dicPos++] = dic[pos];
 412             if (++pos == dicBufSize)
 413               pos = 0;
 414           }
 415           while (--curLen != 0);
 416         }
 417       }
 418     }
 419   }
 420   while (dicPos < limit && buf < bufLimit);
 421   NORMALIZE;
 422   p->buf = buf;
 423   p->range = range;
 424   p->code = code;
 425   p->remainLen = len;
 426   p->dicPos = dicPos;
 427   p->processedPos = processedPos;
 428   p->reps[0] = rep0;
 429   p->reps[1] = rep1;
 430   p->reps[2] = rep2;
 431   p->reps[3] = rep3;
 432   p->state = state;
 433
 434   return SZ_OK;
 435 }
 436
 437 static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)
 438 {
 439   if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)
 440   {
 441     Byte *dic = p->dic;
 442     SizeT dicPos = p->dicPos;
 443     SizeT dicBufSize = p->dicBufSize;
 444     unsigned len = p->remainLen;
 445     UInt32 rep0 = p->reps[0];
 446     if (limit - dicPos < len)
 447       len = (unsigned)(limit - dicPos);
 448
 449     if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
 450       p->checkDicSize = p->prop.dicSize;
 451
 452     p->processedPos += len;
 453     p->remainLen -= len;
 454     while (len-- != 0)
 455     {
 456       dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 457       dicPos++;
 458     }
 459     p->dicPos = dicPos;
 460   }
 461 }
 462
 463 static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
 464 {
 465   do
 466   {
 467     SizeT limit2 = limit;
 468     if (p->checkDicSize == 0)
 469     {
 470       UInt32 rem = p->prop.dicSize - p->processedPos;
 471       if (limit - p->dicPos > rem)
 472         limit2 = p->dicPos + rem;
 473     }
 474     RINOK(LzmaDec_DecodeReal(p, limit2, bufLimit));
 475     if (p->processedPos >= p->prop.dicSize)
 476       p->checkDicSize = p->prop.dicSize;
 477     LzmaDec_WriteRem(p, limit);
 478   }
 479   while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);
 480
 481   if (p->remainLen > kMatchSpecLenStart)
 482   {
 483     p->remainLen = kMatchSpecLenStart;
 484   }
 485   return 0;
 486 }
 487
 488 typedef enum
 489 {
 490   DUMMY_ERROR, /* unexpected end of input stream */
 491   DUMMY_LIT,
 492   DUMMY_MATCH,
 493   DUMMY_REP
 494 } ELzmaDummy;
 495
 496 static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)
 497 {
 498   UInt32 range = p->range;
 499   UInt32 code = p->code;
 500   const Byte *bufLimit = buf + inSize;
 501   CLzmaProb *probs = p->probs;
 502   unsigned state = p->state;
 503   ELzmaDummy res;
 504
 505   {
 506     CLzmaProb *prob;
 507     UInt32 bound;
 508     unsigned ttt;
 509     unsigned posState = (p->processedPos) & ((1 << p->prop.pb) - 1);
 510
 511     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
 512     IF_BIT_0_CHECK(prob)
 513     {
 514       UPDATE_0_CHECK
 515
 516       /* if (bufLimit - buf >= 7) return DUMMY_LIT; */
 517
 518       prob = probs + Literal;
 519       if (p->checkDicSize != 0 || p->processedPos != 0)
 520         prob += (LZMA_LIT_SIZE *
 521           ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +
 522           (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));
 523
 524       if (state < kNumLitStates)
 525       {
 526         unsigned symbol = 1;
 527         do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);
 528       }
 529       else
 530       {
 531         unsigned matchByte = p->dic[p->dicPos - p->reps[0] +
 532             ((p->dicPos < p->reps[0]) ? p->dicBufSize : 0)];
 533         unsigned offs = 0x100;
 534         unsigned symbol = 1;
 535         do
 536         {
 537           unsigned bit;
 538           CLzmaProb *probLit;
 539           matchByte <<= 1;
 540           bit = (matchByte & offs);
 541           probLit = prob + offs + bit + symbol;
 542           GET_BIT2_CHECK(probLit, symbol, offs &= ~bit, offs &= bit)
 543         }
 544         while (symbol < 0x100);
 545       }
 546       res = DUMMY_LIT;
 547     }
 548     else
 549     {
 550       unsigned len;
 551       UPDATE_1_CHECK;
 552
 553       prob = probs + IsRep + state;
 554       IF_BIT_0_CHECK(prob)
 555       {
 556         UPDATE_0_CHECK;
 557         state = 0;
 558         prob = probs + LenCoder;
 559         res = DUMMY_MATCH;
 560       }
 561       else
 562       {
 563         UPDATE_1_CHECK;
 564         res = DUMMY_REP;
 565         prob = probs + IsRepG0 + state;
 566         IF_BIT_0_CHECK(prob)
 567         {
 568           UPDATE_0_CHECK;
 569           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
 570           IF_BIT_0_CHECK(prob)
 571           {
 572             UPDATE_0_CHECK;
 573             NORMALIZE_CHECK;
 574             return DUMMY_REP;
 575           }
 576           else
 577           {
 578             UPDATE_1_CHECK;
 579           }
 580         }
 581         else
 582         {
 583           UPDATE_1_CHECK;
 584           prob = probs + IsRepG1 + state;
 585           IF_BIT_0_CHECK(prob)
 586           {
 587             UPDATE_0_CHECK;
 588           }
 589           else
 590           {
 591             UPDATE_1_CHECK;
 592             prob = probs + IsRepG2 + state;
 593             IF_BIT_0_CHECK(prob)
 594             {
 595               UPDATE_0_CHECK;
 596             }
 597             else
 598             {
 599               UPDATE_1_CHECK;
 600             }
 601           }
 602         }
 603         state = kNumStates;
 604         prob = probs + RepLenCoder;
 605       }
 606       {
 607         unsigned limit, offset;
 608         CLzmaProb *probLen = prob + LenChoice;
 609         IF_BIT_0_CHECK(probLen)
 610         {
 611           UPDATE_0_CHECK;
 612           probLen = prob + LenLow + (posState << kLenNumLowBits);
 613           offset = 0;
 614           limit = 1 << kLenNumLowBits;
 615         }
 616         else
 617         {
 618           UPDATE_1_CHECK;
 619           probLen = prob + LenChoice2;
 620           IF_BIT_0_CHECK(probLen)
 621           {
 622             UPDATE_0_CHECK;
 623             probLen = prob + LenMid + (posState << kLenNumMidBits);
 624             offset = kLenNumLowSymbols;
 625             limit = 1 << kLenNumMidBits;
 626           }
 627           else
 628           {
 629             UPDATE_1_CHECK;
 630             probLen = prob + LenHigh;
 631             offset = kLenNumLowSymbols + kLenNumMidSymbols;
 632             limit = 1 << kLenNumHighBits;
 633           }
 634         }
 635         TREE_DECODE_CHECK(probLen, limit, len);
 636         len += offset;
 637       }
 638
 639       if (state < 4)
 640       {
 641         unsigned posSlot;
 642         prob = probs + PosSlot +
 643             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) <<
 644             kNumPosSlotBits);
 645         TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
 646         if (posSlot >= kStartPosModelIndex)
 647         {
 648           int numDirectBits = ((posSlot >> 1) - 1);
 649
 650           /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */
 651
 652           if (posSlot < kEndPosModelIndex)
 653           {
 654             prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits) - posSlot - 1;
 655           }
 656           else
 657           {
 658             numDirectBits -= kNumAlignBits;
 659             do
 660             {
 661               NORMALIZE_CHECK
 662               range >>= 1;
 663               code -= range & (((code - range) >> 31) - 1);
 664               /* if (code >= range) code -= range; */
 665             }
 666             while (--numDirectBits != 0);
 667             prob = probs + Align;
 668             numDirectBits = kNumAlignBits;
 669           }
 670           {
 671             unsigned i = 1;
 672             do
 673             {
 674               GET_BIT_CHECK(prob + i, i);
 675             }
 676             while (--numDirectBits != 0);
 677           }
 678         }
 679       }
 680     }
 681   }
 682   NORMALIZE_CHECK;
 683   return res;
 684 }
 685
 686
 687 static void LzmaDec_InitRc(CLzmaDec *p, const Byte *data)
 688 {
 689   p->code = ((UInt32)data[1] << 24) | ((UInt32)data[2] << 16) | ((UInt32)data[3] << 8) | ((UInt32)data[4]);
 690   p->range = 0xFFFFFFFF;
 691   p->needFlush = 0;
 692 }
 693
 694 static void LzmaDec_InitDicAndState(CLzmaDec *p, Bool initDic, Bool initState)
 695 {
 696   p->needFlush = 1;
 697   p->remainLen = 0;
 698   p->tempBufSize = 0;
 699
 700   if (initDic)
 701   {
 702     p->processedPos = 0;
 703     p->checkDicSize = 0;
 704     p->needInitState = 1;
 705   }
 706   if (initState)
 707     p->needInitState = 1;
 708 }
 709
 710 void LzmaDec_Init(CLzmaDec *p)
 711 {
 712   p->dicPos = 0;
 713   LzmaDec_InitDicAndState(p, True, True);
 714 }
 715
 716 static void LzmaDec_InitStateReal(CLzmaDec *p)
 717 {
 718   UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (p->prop.lc + p->prop.lp));
 719   UInt32 i;
 720   CLzmaProb *probs = p->probs;
 721   for (i = 0; i < numProbs; i++)
 722     probs[i] = kBitModelTotal >> 1;
 723   p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
 724   p->state = 0;
 725   p->needInitState = 0;
 726 }
 727
 728 SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen,
 729     ELzmaFinishMode finishMode, ELzmaStatus *status)
 730 {
 731   SizeT inSize = *srcLen;
 732   (*srcLen) = 0;
 733   LzmaDec_WriteRem(p, dicLimit);
 734
 735   *status = LZMA_STATUS_NOT_SPECIFIED;
 736
 737   while (p->remainLen != kMatchSpecLenStart)
 738   {
 739       int checkEndMarkNow;
 740
 741       if (p->needFlush != 0)
 742       {
 743         for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
 744           p->tempBuf[p->tempBufSize++] = *src++;
 745         if (p->tempBufSize < RC_INIT_SIZE)
 746         {
 747           *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 748           return SZ_OK;
 749         }
 750         if (p->tempBuf[0] != 0)
 751           return SZ_ERROR_DATA;
 752
 753         LzmaDec_InitRc(p, p->tempBuf);
 754         p->tempBufSize = 0;
 755       }
 756
 757       checkEndMarkNow = 0;
 758       if (p->dicPos >= dicLimit)
 759       {
 760         if (p->remainLen == 0 && p->code == 0)
 761         {
 762           *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
 763           return SZ_OK;
 764         }
 765         if (finishMode == LZMA_FINISH_ANY)
 766         {
 767           *status = LZMA_STATUS_NOT_FINISHED;
 768           return SZ_OK;
 769         }
 770         if (p->remainLen != 0)
 771         {
 772           *status = LZMA_STATUS_NOT_FINISHED;
 773           return SZ_ERROR_DATA;
 774         }
 775         checkEndMarkNow = 1;
 776       }
 777
 778       if (p->needInitState)
 779         LzmaDec_InitStateReal(p);
 780
 781       if (p->tempBufSize == 0)
 782       {
 783         SizeT processed;
 784         const Byte *bufLimit;
 785         if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
 786         {
 787           int dummyRes = LzmaDec_TryDummy(p, src, inSize);
 788           if (dummyRes == DUMMY_ERROR)
 789           {
 790             memcpy(p->tempBuf, src, inSize);
 791             p->tempBufSize = (unsigned)inSize;
 792             (*srcLen) += inSize;
 793             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 794             return SZ_OK;
 795           }
 796           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
 797           {
 798             *status = LZMA_STATUS_NOT_FINISHED;
 799             return SZ_ERROR_DATA;
 800           }
 801           bufLimit = src;
 802         }
 803         else
 804           bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
 805         p->buf = src;
 806         if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
 807           return SZ_ERROR_DATA;
 808         processed = (SizeT)(p->buf - src);
 809         (*srcLen) += processed;
 810         src += processed;
 811         inSize -= processed;
 812       }
 813       else
 814       {
 815         unsigned rem = p->tempBufSize, lookAhead = 0;
 816         while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)
 817           p->tempBuf[rem++] = src[lookAhead++];
 818         p->tempBufSize = rem;
 819         if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
 820         {
 821           int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, rem);
 822           if (dummyRes == DUMMY_ERROR)
 823           {
 824             (*srcLen) += lookAhead;
 825             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 826             return SZ_OK;
 827           }
 828           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
 829           {
 830             *status = LZMA_STATUS_NOT_FINISHED;
 831             return SZ_ERROR_DATA;
 832           }
 833         }
 834         p->buf = p->tempBuf;
 835         if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
 836           return SZ_ERROR_DATA;
 837         lookAhead -= (rem - (unsigned)(p->buf - p->tempBuf));
 838         (*srcLen) += lookAhead;
 839         src += lookAhead;
 840         inSize -= lookAhead;
 841         p->tempBufSize = 0;
 842       }
 843   }
 844   if (p->code == 0)
 845     *status = LZMA_STATUS_FINISHED_WITH_MARK;
 846   return (p->code == 0) ? SZ_OK : SZ_ERROR_DATA;
 847 }
 848
 849 SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status)
 850 {
 851   SizeT outSize = *destLen;
 852   SizeT inSize = *srcLen;
 853   *srcLen = *destLen = 0;
 854   for (;;)
 855   {
 856     SizeT inSizeCur = inSize, outSizeCur, dicPos;
 857     ELzmaFinishMode curFinishMode;
 858     SRes res;
 859     if (p->dicPos == p->dicBufSize)
 860       p->dicPos = 0;
 861     dicPos = p->dicPos;
 862     if (outSize > p->dicBufSize - dicPos)
 863     {
 864       outSizeCur = p->dicBufSize;
 865       curFinishMode = LZMA_FINISH_ANY;
 866     }
 867     else
 868     {
 869       outSizeCur = dicPos + outSize;
 870       curFinishMode = finishMode;
 871     }
 872
 873     res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
 874     src += inSizeCur;
 875     inSize -= inSizeCur;
 876     *srcLen += inSizeCur;
 877     outSizeCur = p->dicPos - dicPos;
 878     memcpy(dest, p->dic + dicPos, outSizeCur);
 879     dest += outSizeCur;
 880     outSize -= outSizeCur;
 881     *destLen += outSizeCur;
 882     if (res != 0)
 883       return res;
 884     if (outSizeCur == 0 || outSize == 0)
 885       return SZ_OK;
 886   }
 887 }
 888
 889 void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc)
 890 {
 891   alloc->Free(alloc, p->probs);
 892   p->probs = 0;
 893 }
 894
 895 static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc)
 896 {
 897   alloc->Free(alloc, p->dic);
 898   p->dic = 0;
 899 }
 900
 901 void LzmaDec_Free(CLzmaDec *p, ISzAlloc *alloc)
 902 {
 903   LzmaDec_FreeProbs(p, alloc);
 904   LzmaDec_FreeDict(p, alloc);
 905 }
 906
 907 SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)
 908 {
 909   UInt32 dicSize;
 910   Byte d;
 911
 912   if (size < LZMA_PROPS_SIZE)
 913     return SZ_ERROR_UNSUPPORTED;
 914   else
 915     dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);
 916
 917   if (dicSize < LZMA_DIC_MIN)
 918     dicSize = LZMA_DIC_MIN;
 919   p->dicSize = dicSize;
 920
 921   d = data[0];
 922   if (d >= (9 * 5 * 5))
 923     return SZ_ERROR_UNSUPPORTED;
 924
 925   p->lc = d % 9;
 926   d /= 9;
 927   p->pb = d / 5;
 928   p->lp = d % 5;
 929
 930   return SZ_OK;
 931 }
 932
 933 static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAlloc *alloc)
 934 {
 935   UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
 936   if (p->probs == 0 || numProbs != p->numProbs)
 937   {
 938     LzmaDec_FreeProbs(p, alloc);
 939     p->probs = (CLzmaProb *)alloc->Alloc(alloc, numProbs * sizeof(CLzmaProb));
 940     p->numProbs = numProbs;
 941     if (p->probs == 0)
 942       return SZ_ERROR_MEM;
 943   }
 944   return SZ_OK;
 945 }
 946
 947 SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
 948 {
 949   CLzmaProps propNew;
 950   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
 951   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
 952   p->prop = propNew;
 953   return SZ_OK;
 954 }
 955
 956 SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
 957 {
 958   CLzmaProps propNew;
 959   SizeT dicBufSize;
 960   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
 961   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
 962   dicBufSize = propNew.dicSize;
 963   if (p->dic == 0 || dicBufSize != p->dicBufSize)
 964   {
 965     LzmaDec_FreeDict(p, alloc);
 966     p->dic = (Byte *)alloc->Alloc(alloc, dicBufSize);
 967     if (p->dic == 0)
 968     {
 969       LzmaDec_FreeProbs(p, alloc);
 970       return SZ_ERROR_MEM;
 971     }
 972   }
 973   p->dicBufSize = dicBufSize;
 974   p->prop = propNew;
 975   return SZ_OK;
 976 }
 977
 978 SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
 979     const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
 980     ELzmaStatus *status, ISzAlloc *alloc)
 981 {
 982   CLzmaDec p;
 983   SRes res;
 984   SizeT inSize = *srcLen;
 985   SizeT outSize = *destLen;
 986   *srcLen = *destLen = 0;
 987   if (inSize < RC_INIT_SIZE)
 988     return SZ_ERROR_INPUT_EOF;
 989
 990   LzmaDec_Construct(&p);
 991   res = LzmaDec_AllocateProbs(&p, propData, propSize, alloc);
 992   if (res != 0)
 993     return res;
 994   p.dic = dest;
 995   p.dicBufSize = outSize;
 996
 997   LzmaDec_Init(&p);
 998
 999   *srcLen = inSize;
1000   res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);
1001
1002   if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
1003     res = SZ_ERROR_INPUT_EOF;
1004
1005   (*destLen) = p.dicPos;
1006   LzmaDec_FreeProbs(&p, alloc);
1007   return res;
1008 }