usr/src/common/lzma/LzmaDec.c

   1 /*
   2  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5
   6 /* LzmaDec.c -- LZMA Decoder
   7 2008-11-06 : Igor Pavlov : Public domain */
   8
   9 #include "LzmaDec.h"
  10
  11 #ifndef _KERNEL
  12 #include <string.h>
  13 #endif /* _KERNEL */
  14
  15 #define kNumTopBits 24
  16 #define kTopValue ((UInt32)1 << kNumTopBits)
  17
  18 #define kNumBitModelTotalBits 11
  19 #define kBitModelTotal (1 << kNumBitModelTotalBits)
  20 #define kNumMoveBits 5
  21
  22 #define RC_INIT_SIZE 5
  23
  24 #define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); }
  25
  26 #define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
  27 #define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
  28 #define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
  29 #define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \
  30   { UPDATE_0(p); i = (i + i); A0; } else \
  31   { UPDATE_1(p); i = (i + i) + 1; A1; }
  32 #define GET_BIT(p, i) GET_BIT2(p, i, ; , ;)
  33
  34 #define TREE_GET_BIT(probs, i) { GET_BIT((probs + i), i); }
  35 #define TREE_DECODE(probs, limit, i) \
  36   { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }
  37
  38 /* #define _LZMA_SIZE_OPT */
  39
  40 #ifdef _LZMA_SIZE_OPT
  41 #define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
  42 #else
  43 #define TREE_6_DECODE(probs, i) \
  44   { i = 1; \
  45   TREE_GET_BIT(probs, i); \
  46   TREE_GET_BIT(probs, i); \
  47   TREE_GET_BIT(probs, i); \
  48   TREE_GET_BIT(probs, i); \
  49   TREE_GET_BIT(probs, i); \
  50   TREE_GET_BIT(probs, i); \
  51   i -= 0x40; }
  52 #endif
  53
  54 #define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_ERROR; range <<= 8; code = (code << 8) | (*buf++); }
  55
  56 #define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
  57 #define UPDATE_0_CHECK range = bound;
  58 #define UPDATE_1_CHECK range -= bound; code -= bound;
  59 #define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \
  60   { UPDATE_0_CHECK; i = (i + i); A0; } else \
  61   { UPDATE_1_CHECK; i = (i + i) + 1; A1; }
  62 #define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)
  63 #define TREE_DECODE_CHECK(probs, limit, i) \
  64   { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }
  65
  66
  67 #define kNumPosBitsMax 4
  68 #define kNumPosStatesMax (1 << kNumPosBitsMax)
  69
  70 #define kLenNumLowBits 3
  71 #define kLenNumLowSymbols (1 << kLenNumLowBits)
  72 #define kLenNumMidBits 3
  73 #define kLenNumMidSymbols (1 << kLenNumMidBits)
  74 #define kLenNumHighBits 8
  75 #define kLenNumHighSymbols (1 << kLenNumHighBits)
  76
  77 #define LenChoice 0
  78 #define LenChoice2 (LenChoice + 1)
  79 #define LenLow (LenChoice2 + 1)
  80 #define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))
  81 #define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))
  82 #define kNumLenProbs (LenHigh + kLenNumHighSymbols)
  83
  84
  85 #define kNumStates 12
  86 #define kNumLitStates 7
  87
  88 #define kStartPosModelIndex 4
  89 #define kEndPosModelIndex 14
  90 #define kNumFullDistances (1 << (kEndPosModelIndex >> 1))
  91
  92 #define kNumPosSlotBits 6
  93 #define kNumLenToPosStates 4
  94
  95 #define kNumAlignBits 4
  96 #define kAlignTableSize (1 << kNumAlignBits)
  97
  98 #define kMatchMinLen 2
  99 #define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols + kLenNumMidSymbols + kLenNumHighSymbols)
 100
 101 #define IsMatch 0
 102 #define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))
 103 #define IsRepG0 (IsRep + kNumStates)
 104 #define IsRepG1 (IsRepG0 + kNumStates)
 105 #define IsRepG2 (IsRepG1 + kNumStates)
 106 #define IsRep0Long (IsRepG2 + kNumStates)
 107 #define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))
 108 #define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
 109 #define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)
 110 #define LenCoder (Align + kAlignTableSize)
 111 #define RepLenCoder (LenCoder + kNumLenProbs)
 112 #define Literal (RepLenCoder + kNumLenProbs)
 113
 114 #define LZMA_BASE_SIZE 1846
 115 #define LZMA_LIT_SIZE 768
 116
 117 #define LzmaProps_GetNumProbs(p) ((UInt32)LZMA_BASE_SIZE + (LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))
 118
 119 #if Literal != LZMA_BASE_SIZE
 120 StopCompilingDueBUG
 121 #endif
 122
 123 static const Byte kLiteralNextStates[kNumStates * 2] =
 124 {
 125   0, 0, 0, 0, 1, 2, 3,  4,  5,  6,  4,  5,
 126   7, 7, 7, 7, 7, 7, 7, 10, 10, 10, 10, 10
 127 };
 128
 129 #ifdef _KERNEL
 130 extern void *memcpy(void *, const void *, size_t);
 131 #endif /* _KERNEL */
 132
 133 #define LZMA_DIC_MIN (1 << 12)
 134
 135 /* First LZMA-symbol is always decoded.
 136 And it decodes new LZMA-symbols while (buf < bufLimit), but "buf" is without last normalization
 137 Out:
 138   Result:
 139     SZ_OK - OK
 140     SZ_ERROR_DATA - Error
 141   p->remainLen:
 142     < kMatchSpecLenStart : normal remain
 143     = kMatchSpecLenStart : finished
 144     = kMatchSpecLenStart + 1 : Flush marker
 145     = kMatchSpecLenStart + 2 : State Init Marker
 146 */
 147
 148 static int MY_FAST_CALL LzmaDec_DecodeReal(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
 149 {
 150   CLzmaProb *probs = p->probs;
 151
 152   unsigned state = p->state;
 153   UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];
 154   unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;
 155   unsigned lpMask = ((unsigned)1 << (p->prop.lp)) - 1;
 156   unsigned lc = p->prop.lc;
 157
 158   Byte *dic = p->dic;
 159   SizeT dicBufSize = p->dicBufSize;
 160   SizeT dicPos = p->dicPos;
 161
 162   UInt32 processedPos = p->processedPos;
 163   UInt32 checkDicSize = p->checkDicSize;
 164   unsigned len = 0;
 165
 166   const Byte *buf = p->buf;
 167   UInt32 range = p->range;
 168   UInt32 code = p->code;
 169
 170   do
 171   {
 172     CLzmaProb *prob;
 173     UInt32 bound;
 174     unsigned ttt;
 175     unsigned posState = processedPos & pbMask;
 176
 177     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
 178     IF_BIT_0(prob)
 179     {
 180       unsigned symbol;
 181       UPDATE_0(prob);
 182       prob = probs + Literal;
 183       if (checkDicSize != 0 || processedPos != 0)
 184         prob += (LZMA_LIT_SIZE * (((processedPos & lpMask) << lc) +
 185         (dic[(dicPos == 0 ? dicBufSize : dicPos) - 1] >> (8 - lc))));
 186
 187       if (state < kNumLitStates)
 188       {
 189         symbol = 1;
 190         do { GET_BIT(prob + symbol, symbol) } while (symbol < 0x100);
 191       }
 192       else
 193       {
 194         unsigned matchByte = p->dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 195         unsigned offs = 0x100;
 196         symbol = 1;
 197         do
 198         {
 199           unsigned bit;
 200           CLzmaProb *probLit;
 201           matchByte <<= 1;
 202           bit = (matchByte & offs);
 203           probLit = prob + offs + bit + symbol;
 204           GET_BIT2(probLit, symbol, offs &= ~bit, offs &= bit)
 205         }
 206         while (symbol < 0x100);
 207       }
 208       dic[dicPos++] = (Byte)symbol;
 209       processedPos++;
 210
 211       state = kLiteralNextStates[state];
 212       /* if (state < 4) state = 0; else if (state < 10) state -= 3; else state -= 6; */
 213       continue;
 214     }
 215     else
 216     {
 217       UPDATE_1(prob);
 218       prob = probs + IsRep + state;
 219       IF_BIT_0(prob)
 220       {
 221         UPDATE_0(prob);
 222         state += kNumStates;
 223         prob = probs + LenCoder;
 224       }
 225       else
 226       {
 227         UPDATE_1(prob);
 228         if (checkDicSize == 0 && processedPos == 0)
 229           return SZ_ERROR_DATA;
 230         prob = probs + IsRepG0 + state;
 231         IF_BIT_0(prob)
 232         {
 233           UPDATE_0(prob);
 234           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
 235           IF_BIT_0(prob)
 236           {
 237             UPDATE_0(prob);
 238             dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 239             dicPos++;
 240             processedPos++;
 241             state = state < kNumLitStates ? 9 : 11;
 242             continue;
 243           }
 244           UPDATE_1(prob);
 245         }
 246         else
 247         {
 248           UInt32 distance;
 249           UPDATE_1(prob);
 250           prob = probs + IsRepG1 + state;
 251           IF_BIT_0(prob)
 252           {
 253             UPDATE_0(prob);
 254             distance = rep1;
 255           }
 256           else
 257           {
 258             UPDATE_1(prob);
 259             prob = probs + IsRepG2 + state;
 260             IF_BIT_0(prob)
 261             {
 262               UPDATE_0(prob);
 263               distance = rep2;
 264             }
 265             else
 266             {
 267               UPDATE_1(prob);
 268               distance = rep3;
 269               rep3 = rep2;
 270             }
 271             rep2 = rep1;
 272           }
 273           rep1 = rep0;
 274           rep0 = distance;
 275         }
 276         state = state < kNumLitStates ? 8 : 11;
 277         prob = probs + RepLenCoder;
 278       }
 279       {
 280         unsigned limit, offset;
 281         CLzmaProb *probLen = prob + LenChoice;
 282         IF_BIT_0(probLen)
 283         {
 284           UPDATE_0(probLen);
 285           probLen = prob + LenLow + (posState << kLenNumLowBits);
 286           offset = 0;
 287           limit = (1 << kLenNumLowBits);
 288         }
 289         else
 290         {
 291           UPDATE_1(probLen);
 292           probLen = prob + LenChoice2;
 293           IF_BIT_0(probLen)
 294           {
 295             UPDATE_0(probLen);
 296             probLen = prob + LenMid + (posState << kLenNumMidBits);
 297             offset = kLenNumLowSymbols;
 298             limit = (1 << kLenNumMidBits);
 299           }
 300           else
 301           {
 302             UPDATE_1(probLen);
 303             probLen = prob + LenHigh;
 304             offset = kLenNumLowSymbols + kLenNumMidSymbols;
 305             limit = (1 << kLenNumHighBits);
 306           }
 307         }
 308         TREE_DECODE(probLen, limit, len);
 309         len += offset;
 310       }
 311
 312       if (state >= kNumStates)
 313       {
 314         UInt32 distance;
 315         prob = probs + PosSlot +
 316             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
 317         TREE_6_DECODE(prob, distance);
 318         if (distance >= kStartPosModelIndex)
 319         {
 320           unsigned posSlot = (unsigned)distance;
 321           int numDirectBits = (int)(((distance >> 1) - 1));
 322           distance = (2 | (distance & 1));
 323           if (posSlot < kEndPosModelIndex)
 324           {
 325             distance <<= numDirectBits;
 326             prob = probs + SpecPos + distance - posSlot - 1;
 327             {
 328               UInt32 mask = 1;
 329               unsigned i = 1;
 330               do
 331               {
 332                 GET_BIT2(prob + i, i, ; , distance |= mask);
 333                 mask <<= 1;
 334               }
 335               while (--numDirectBits != 0);
 336             }
 337           }
 338           else
 339           {
 340             numDirectBits -= kNumAlignBits;
 341             do
 342             {
 343               NORMALIZE
 344               range >>= 1;
 345
 346               {
 347                 UInt32 t;
 348                 code -= range;
 349                 t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */
 350                 distance = (distance << 1) + (t + 1);
 351                 code += range & t;
 352               }
 353               /*
 354               distance <<= 1;
 355               if (code >= range)
 356               {
 357                 code -= range;
 358                 distance |= 1;
 359               }
 360               */
 361             }
 362             while (--numDirectBits != 0);
 363             prob = probs + Align;
 364             distance <<= kNumAlignBits;
 365             {
 366               unsigned i = 1;
 367               GET_BIT2(prob + i, i, ; , distance |= 1);
 368               GET_BIT2(prob + i, i, ; , distance |= 2);
 369               GET_BIT2(prob + i, i, ; , distance |= 4);
 370               GET_BIT2(prob + i, i, ; , distance |= 8);
 371             }
 372             if (distance == (UInt32)0xFFFFFFFF)
 373             {
 374               len += kMatchSpecLenStart;
 375               state -= kNumStates;
 376               break;
 377             }
 378           }
 379         }
 380         rep3 = rep2;
 381         rep2 = rep1;
 382         rep1 = rep0;
 383         rep0 = distance + 1;
 384         if (checkDicSize == 0)
 385         {
 386           if (distance >= processedPos)
 387             return SZ_ERROR_DATA;
 388         }
 389         else if (distance >= checkDicSize)
 390           return SZ_ERROR_DATA;
 391         state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
 392         /* state = kLiteralNextStates[state]; */
 393       }
 394
 395       len += kMatchMinLen;
 396
 397       if (limit == dicPos)
 398         return SZ_ERROR_DATA;
 399       {
 400         SizeT rem = limit - dicPos;
 401         unsigned curLen = ((rem < len) ? (unsigned)rem : len);
 402         SizeT pos = (dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0);
 403
 404         processedPos += curLen;
 405
 406         len -= curLen;
 407         if (pos + curLen <= dicBufSize)
 408         {
 409           Byte *dest = dic + dicPos;
 410           ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;
 411           const Byte *lim = dest + curLen;
 412           dicPos += curLen;
 413           do
 414             *(dest) = (Byte)*(dest + src);
 415           while (++dest != lim);
 416         }
 417         else
 418         {
 419           do
 420           {
 421             dic[dicPos++] = dic[pos];
 422             if (++pos == dicBufSize)
 423               pos = 0;
 424           }
 425           while (--curLen != 0);
 426         }
 427       }
 428     }
 429   }
 430   while (dicPos < limit && buf < bufLimit);
 431   NORMALIZE;
 432   p->buf = buf;
 433   p->range = range;
 434   p->code = code;
 435   p->remainLen = len;
 436   p->dicPos = dicPos;
 437   p->processedPos = processedPos;
 438   p->reps[0] = rep0;
 439   p->reps[1] = rep1;
 440   p->reps[2] = rep2;
 441   p->reps[3] = rep3;
 442   p->state = state;
 443
 444   return SZ_OK;
 445 }
 446
 447 static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)
 448 {
 449   if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)
 450   {
 451     Byte *dic = p->dic;
 452     SizeT dicPos = p->dicPos;
 453     SizeT dicBufSize = p->dicBufSize;
 454     unsigned len = p->remainLen;
 455     UInt32 rep0 = p->reps[0];
 456     if (limit - dicPos < len)
 457       len = (unsigned)(limit - dicPos);
 458
 459     if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
 460       p->checkDicSize = p->prop.dicSize;
 461
 462     p->processedPos += len;
 463     p->remainLen -= len;
 464     while (len-- != 0)
 465     {
 466       dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 467       dicPos++;
 468     }
 469     p->dicPos = dicPos;
 470   }
 471 }
 472
 473 static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
 474 {
 475   do
 476   {
 477     SizeT limit2 = limit;
 478     if (p->checkDicSize == 0)
 479     {
 480       UInt32 rem = p->prop.dicSize - p->processedPos;
 481       if (limit - p->dicPos > rem)
 482         limit2 = p->dicPos + rem;
 483     }
 484     RINOK(LzmaDec_DecodeReal(p, limit2, bufLimit));
 485     if (p->processedPos >= p->prop.dicSize)
 486       p->checkDicSize = p->prop.dicSize;
 487     LzmaDec_WriteRem(p, limit);
 488   }
 489   while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);
 490
 491   if (p->remainLen > kMatchSpecLenStart)
 492   {
 493     p->remainLen = kMatchSpecLenStart;
 494   }
 495   return 0;
 496 }
 497
 498 typedef enum
 499 {
 500   DUMMY_ERROR, /* unexpected end of input stream */
 501   DUMMY_LIT,
 502   DUMMY_MATCH,
 503   DUMMY_REP
 504 } ELzmaDummy;
 505
 506 static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)
 507 {
 508   UInt32 range = p->range;
 509   UInt32 code = p->code;
 510   const Byte *bufLimit = buf + inSize;
 511   CLzmaProb *probs = p->probs;
 512   unsigned state = p->state;
 513   ELzmaDummy res;
 514
 515   {
 516     CLzmaProb *prob;
 517     UInt32 bound;
 518     unsigned ttt;
 519     unsigned posState = (p->processedPos) & ((1 << p->prop.pb) - 1);
 520
 521     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
 522     IF_BIT_0_CHECK(prob)
 523     {
 524       UPDATE_0_CHECK
 525
 526       /* if (bufLimit - buf >= 7) return DUMMY_LIT; */
 527
 528       prob = probs + Literal;
 529       if (p->checkDicSize != 0 || p->processedPos != 0)
 530         prob += (LZMA_LIT_SIZE *
 531           ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +
 532           (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));
 533
 534       if (state < kNumLitStates)
 535       {
 536         unsigned symbol = 1;
 537         do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);
 538       }
 539       else
 540       {
 541         unsigned matchByte = p->dic[p->dicPos - p->reps[0] +
 542             ((p->dicPos < p->reps[0]) ? p->dicBufSize : 0)];
 543         unsigned offs = 0x100;
 544         unsigned symbol = 1;
 545         do
 546         {
 547           unsigned bit;
 548           CLzmaProb *probLit;
 549           matchByte <<= 1;
 550           bit = (matchByte & offs);
 551           probLit = prob + offs + bit + symbol;
 552           GET_BIT2_CHECK(probLit, symbol, offs &= ~bit, offs &= bit)
 553         }
 554         while (symbol < 0x100);
 555       }
 556       res = DUMMY_LIT;
 557     }
 558     else
 559     {
 560       unsigned len;
 561       UPDATE_1_CHECK;
 562
 563       prob = probs + IsRep + state;
 564       IF_BIT_0_CHECK(prob)
 565       {
 566         UPDATE_0_CHECK;
 567         state = 0;
 568         prob = probs + LenCoder;
 569         res = DUMMY_MATCH;
 570       }
 571       else
 572       {
 573         UPDATE_1_CHECK;
 574         res = DUMMY_REP;
 575         prob = probs + IsRepG0 + state;
 576         IF_BIT_0_CHECK(prob)
 577         {
 578           UPDATE_0_CHECK;
 579           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
 580           IF_BIT_0_CHECK(prob)
 581           {
 582             UPDATE_0_CHECK;
 583             NORMALIZE_CHECK;
 584             return DUMMY_REP;
 585           }
 586           else
 587           {
 588             UPDATE_1_CHECK;
 589           }
 590         }
 591         else
 592         {
 593           UPDATE_1_CHECK;
 594           prob = probs + IsRepG1 + state;
 595           IF_BIT_0_CHECK(prob)
 596           {
 597             UPDATE_0_CHECK;
 598           }
 599           else
 600           {
 601             UPDATE_1_CHECK;
 602             prob = probs + IsRepG2 + state;
 603             IF_BIT_0_CHECK(prob)
 604             {
 605               UPDATE_0_CHECK;
 606             }
 607             else
 608             {
 609               UPDATE_1_CHECK;
 610             }
 611           }
 612         }
 613         state = kNumStates;
 614         prob = probs + RepLenCoder;
 615       }
 616       {
 617         unsigned limit, offset;
 618         CLzmaProb *probLen = prob + LenChoice;
 619         IF_BIT_0_CHECK(probLen)
 620         {
 621           UPDATE_0_CHECK;
 622           probLen = prob + LenLow + (posState << kLenNumLowBits);
 623           offset = 0;
 624           limit = 1 << kLenNumLowBits;
 625         }
 626         else
 627         {
 628           UPDATE_1_CHECK;
 629           probLen = prob + LenChoice2;
 630           IF_BIT_0_CHECK(probLen)
 631           {
 632             UPDATE_0_CHECK;
 633             probLen = prob + LenMid + (posState << kLenNumMidBits);
 634             offset = kLenNumLowSymbols;
 635             limit = 1 << kLenNumMidBits;
 636           }
 637           else
 638           {
 639             UPDATE_1_CHECK;
 640             probLen = prob + LenHigh;
 641             offset = kLenNumLowSymbols + kLenNumMidSymbols;
 642             limit = 1 << kLenNumHighBits;
 643           }
 644         }
 645         TREE_DECODE_CHECK(probLen, limit, len);
 646         len += offset;
 647       }
 648
 649       if (state < 4)
 650       {
 651         unsigned posSlot;
 652         prob = probs + PosSlot +
 653             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) <<
 654             kNumPosSlotBits);
 655         TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
 656         if (posSlot >= kStartPosModelIndex)
 657         {
 658           int numDirectBits = ((posSlot >> 1) - 1);
 659
 660           /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */
 661
 662           if (posSlot < kEndPosModelIndex)
 663           {
 664             prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits) - posSlot - 1;
 665           }
 666           else
 667           {
 668             numDirectBits -= kNumAlignBits;
 669             do
 670             {
 671               NORMALIZE_CHECK
 672               range >>= 1;
 673               code -= range & (((code - range) >> 31) - 1);
 674               /* if (code >= range) code -= range; */
 675             }
 676             while (--numDirectBits != 0);
 677             prob = probs + Align;
 678             numDirectBits = kNumAlignBits;
 679           }
 680           {
 681             unsigned i = 1;
 682             do
 683             {
 684               GET_BIT_CHECK(prob + i, i);
 685             }
 686             while (--numDirectBits != 0);
 687           }
 688         }
 689       }
 690     }
 691   }
 692   NORMALIZE_CHECK;
 693   return res;
 694 }
 695
 696
 697 static void LzmaDec_InitRc(CLzmaDec *p, const Byte *data)
 698 {
 699   p->code = ((UInt32)data[1] << 24) | ((UInt32)data[2] << 16) | ((UInt32)data[3] << 8) | ((UInt32)data[4]);
 700   p->range = 0xFFFFFFFF;
 701   p->needFlush = 0;
 702 }
 703
 704 void LzmaDec_InitDicAndState(CLzmaDec *p, Bool initDic, Bool initState)
 705 {
 706   p->needFlush = 1;
 707   p->remainLen = 0;
 708   p->tempBufSize = 0;
 709
 710   if (initDic)
 711   {
 712     p->processedPos = 0;
 713     p->checkDicSize = 0;
 714     p->needInitState = 1;
 715   }
 716   if (initState)
 717     p->needInitState = 1;
 718 }
 719
 720 void LzmaDec_Init(CLzmaDec *p)
 721 {
 722   p->dicPos = 0;
 723   LzmaDec_InitDicAndState(p, True, True);
 724 }
 725
 726 static void LzmaDec_InitStateReal(CLzmaDec *p)
 727 {
 728   UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (p->prop.lc + p->prop.lp));
 729   UInt32 i;
 730   CLzmaProb *probs = p->probs;
 731   for (i = 0; i < numProbs; i++)
 732     probs[i] = kBitModelTotal >> 1;
 733   p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
 734   p->state = 0;
 735   p->needInitState = 0;
 736 }
 737
 738 SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen,
 739     ELzmaFinishMode finishMode, ELzmaStatus *status)
 740 {
 741   SizeT inSize = *srcLen;
 742   (*srcLen) = 0;
 743   LzmaDec_WriteRem(p, dicLimit);
 744
 745   *status = LZMA_STATUS_NOT_SPECIFIED;
 746
 747   while (p->remainLen != kMatchSpecLenStart)
 748   {
 749       int checkEndMarkNow;
 750
 751       if (p->needFlush != 0)
 752       {
 753         for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
 754           p->tempBuf[p->tempBufSize++] = *src++;
 755         if (p->tempBufSize < RC_INIT_SIZE)
 756         {
 757           *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 758           return SZ_OK;
 759         }
 760         if (p->tempBuf[0] != 0)
 761           return SZ_ERROR_DATA;
 762
 763         LzmaDec_InitRc(p, p->tempBuf);
 764         p->tempBufSize = 0;
 765       }
 766
 767       checkEndMarkNow = 0;
 768       if (p->dicPos >= dicLimit)
 769       {
 770         if (p->remainLen == 0 && p->code == 0)
 771         {
 772           *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
 773           return SZ_OK;
 774         }
 775         if (finishMode == LZMA_FINISH_ANY)
 776         {
 777           *status = LZMA_STATUS_NOT_FINISHED;
 778           return SZ_OK;
 779         }
 780         if (p->remainLen != 0)
 781         {
 782           *status = LZMA_STATUS_NOT_FINISHED;
 783           return SZ_ERROR_DATA;
 784         }
 785         checkEndMarkNow = 1;
 786       }
 787
 788       if (p->needInitState)
 789         LzmaDec_InitStateReal(p);
 790
 791       if (p->tempBufSize == 0)
 792       {
 793         SizeT processed;
 794         const Byte *bufLimit;
 795         if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
 796         {
 797           int dummyRes = LzmaDec_TryDummy(p, src, inSize);
 798           if (dummyRes == DUMMY_ERROR)
 799           {
 800             (void) memcpy(p->tempBuf, src, inSize);
 801             p->tempBufSize = (unsigned)inSize;
 802             (*srcLen) += inSize;
 803             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 804             return SZ_OK;
 805           }
 806           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
 807           {
 808             *status = LZMA_STATUS_NOT_FINISHED;
 809             return SZ_ERROR_DATA;
 810           }
 811           bufLimit = src;
 812         }
 813         else
 814           bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
 815         p->buf = src;
 816         if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
 817           return SZ_ERROR_DATA;
 818         /*LINTED*/
 819         processed = (SizeT)(p->buf - src);
 820         (*srcLen) += processed;
 821         src += processed;
 822         inSize -= processed;
 823       }
 824       else
 825       {
 826         unsigned rem = p->tempBufSize, lookAhead = 0;
 827         while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)
 828           p->tempBuf[rem++] = src[lookAhead++];
 829         p->tempBufSize = rem;
 830         if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
 831         {
 832           int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, rem);
 833           if (dummyRes == DUMMY_ERROR)
 834           {
 835             (*srcLen) += lookAhead;
 836             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 837             return SZ_OK;
 838           }
 839           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
 840           {
 841             *status = LZMA_STATUS_NOT_FINISHED;
 842             return SZ_ERROR_DATA;
 843           }
 844         }
 845         p->buf = p->tempBuf;
 846         if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
 847           return SZ_ERROR_DATA;
 848         /*LINTED*/
 849         lookAhead -= (rem - (unsigned)(p->buf - p->tempBuf));
 850         (*srcLen) += lookAhead;
 851         src += lookAhead;
 852         inSize -= lookAhead;
 853         p->tempBufSize = 0;
 854       }
 855   }
 856   if (p->code == 0)
 857     *status = LZMA_STATUS_FINISHED_WITH_MARK;
 858   return (p->code == 0) ? SZ_OK : SZ_ERROR_DATA;
 859 }
 860
 861 SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status)
 862 {
 863   SizeT outSize = *destLen;
 864   SizeT inSize = *srcLen;
 865   *srcLen = *destLen = 0;
 866   for (;;)
 867   {
 868     SizeT inSizeCur = inSize, outSizeCur, dicPos;
 869     ELzmaFinishMode curFinishMode;
 870     SRes res;
 871     if (p->dicPos == p->dicBufSize)
 872       p->dicPos = 0;
 873     dicPos = p->dicPos;
 874     if (outSize > p->dicBufSize - dicPos)
 875     {
 876       outSizeCur = p->dicBufSize;
 877       curFinishMode = LZMA_FINISH_ANY;
 878     }
 879     else
 880     {
 881       outSizeCur = dicPos + outSize;
 882       curFinishMode = finishMode;
 883     }
 884
 885     res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
 886     src += inSizeCur;
 887     inSize -= inSizeCur;
 888     *srcLen += inSizeCur;
 889     outSizeCur = p->dicPos - dicPos;
 890     (void) memcpy(dest, p->dic + dicPos, outSizeCur);
 891     dest += outSizeCur;
 892     outSize -= outSizeCur;
 893     *destLen += outSizeCur;
 894     if (res != 0)
 895       return res;
 896     if (outSizeCur == 0 || outSize == 0)
 897       return SZ_OK;
 898   }
 899 }
 900
 901 void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc)
 902 {
 903   if (p->probs != 0)
 904         alloc->Free(alloc, p->probs, (p->numProbs * sizeof (*p->probs)));
 905   p->probs = 0;
 906 }
 907
 908 static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc)
 909 {
 910   if (p->dic != 0)
 911         alloc->Free(alloc, p->dic, ((p->prop).dicSize * sizeof (*p->dic)));
 912   p->dic = 0;
 913 }
 914
 915 void LzmaDec_Free(CLzmaDec *p, ISzAlloc *alloc)
 916 {
 917   LzmaDec_FreeProbs(p, alloc);
 918   LzmaDec_FreeDict(p, alloc);
 919 }
 920
 921 SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)
 922 {
 923   UInt32 dicSize;
 924   Byte d;
 925
 926   if (size < LZMA_PROPS_SIZE)
 927     return SZ_ERROR_UNSUPPORTED;
 928   else
 929     dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);
 930
 931   if (dicSize < LZMA_DIC_MIN)
 932     dicSize = LZMA_DIC_MIN;
 933   p->dicSize = dicSize;
 934
 935   d = data[0];
 936   if (d >= (9 * 5 * 5))
 937     return SZ_ERROR_UNSUPPORTED;
 938
 939   p->lc = d % 9;
 940   d /= 9;
 941   p->pb = d / 5;
 942   p->lp = d % 5;
 943
 944   return SZ_OK;
 945 }
 946
 947 static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAlloc *alloc)
 948 {
 949   UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
 950   if (p->probs == 0 || numProbs != p->numProbs)
 951   {
 952     LzmaDec_FreeProbs(p, alloc);
 953     p->probs = (CLzmaProb *)alloc->Alloc(alloc, numProbs * sizeof(CLzmaProb));
 954     p->numProbs = numProbs;
 955     if (p->probs == 0)
 956       return SZ_ERROR_MEM;
 957   }
 958   return SZ_OK;
 959 }
 960
 961 SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
 962 {
 963   CLzmaProps propNew;
 964   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
 965   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
 966   p->prop = propNew;
 967   return SZ_OK;
 968 }
 969
 970 SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
 971 {
 972   CLzmaProps propNew;
 973   SizeT dicBufSize;
 974   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
 975   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
 976   dicBufSize = propNew.dicSize;
 977   if (p->dic == 0 || dicBufSize != p->dicBufSize)
 978   {
 979     LzmaDec_FreeDict(p, alloc);
 980     p->dic = (Byte *)alloc->Alloc(alloc, dicBufSize);
 981     if (p->dic == 0)
 982     {
 983       LzmaDec_FreeProbs(p, alloc);
 984       return SZ_ERROR_MEM;
 985     }
 986   }
 987   p->dicBufSize = dicBufSize;
 988   p->prop = propNew;
 989   return SZ_OK;
 990 }
 991
 992 SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
 993     const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
 994     ELzmaStatus *status, ISzAlloc *alloc)
 995 {
 996   CLzmaDec p;
 997   SRes res;
 998   SizeT inSize = *srcLen;
 999   SizeT outSize = *destLen;
1000   *srcLen = *destLen = 0;
1001   if (inSize < RC_INIT_SIZE)
1002     return SZ_ERROR_INPUT_EOF;
1003
1004   LzmaDec_Construct(&p);
1005   res = LzmaDec_AllocateProbs(&p, propData, propSize, alloc);
1006   if (res != 0)
1007     return res;
1008   p.dic = dest;
1009   p.dicBufSize = outSize;
1010
1011   LzmaDec_Init(&p);
1012
1013   *srcLen = inSize;
1014   res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);
1015
1016   if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
1017     res = SZ_ERROR_INPUT_EOF;
1018
1019   (*destLen) = p.dicPos;
1020   LzmaDec_FreeProbs(&p, alloc);
1021   return res;
1022 }