uboot/lib/lzma/LzmaDec.c
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   1/* LzmaDec.c -- LZMA Decoder
   22008-11-06 : Igor Pavlov : Public domain */
   3
   4#include <config.h>
   5#include <common.h>
   6#include <watchdog.h>
   7#include "LzmaDec.h"
   8
   9#include <linux/string.h>
  10
  11#define kNumTopBits 24
  12#define kTopValue ((UInt32)1 << kNumTopBits)
  13
  14#define kNumBitModelTotalBits 11
  15#define kBitModelTotal (1 << kNumBitModelTotalBits)
  16#define kNumMoveBits 5
  17
  18#define RC_INIT_SIZE 5
  19
  20#define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); }
  21
  22#define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
  23#define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
  24#define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
  25#define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \
  26  { UPDATE_0(p); i = (i + i); A0; } else \
  27  { UPDATE_1(p); i = (i + i) + 1; A1; }
  28#define GET_BIT(p, i) GET_BIT2(p, i, ; , ;)
  29
  30#define TREE_GET_BIT(probs, i) { GET_BIT((probs + i), i); }
  31#define TREE_DECODE(probs, limit, i) \
  32  { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }
  33
  34/* #define _LZMA_SIZE_OPT */
  35
  36#ifdef _LZMA_SIZE_OPT
  37#define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
  38#else
  39#define TREE_6_DECODE(probs, i) \
  40  { i = 1; \
  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  TREE_GET_BIT(probs, i); \
  47  i -= 0x40; }
  48#endif
  49
  50#define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_ERROR; range <<= 8; code = (code << 8) | (*buf++); }
  51
  52#define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
  53#define UPDATE_0_CHECK range = bound;
  54#define UPDATE_1_CHECK range -= bound; code -= bound;
  55#define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \
  56  { UPDATE_0_CHECK; i = (i + i); A0; } else \
  57  { UPDATE_1_CHECK; i = (i + i) + 1; A1; }
  58#define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)
  59#define TREE_DECODE_CHECK(probs, limit, i) \
  60  { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }
  61
  62
  63#define kNumPosBitsMax 4
  64#define kNumPosStatesMax (1 << kNumPosBitsMax)
  65
  66#define kLenNumLowBits 3
  67#define kLenNumLowSymbols (1 << kLenNumLowBits)
  68#define kLenNumMidBits 3
  69#define kLenNumMidSymbols (1 << kLenNumMidBits)
  70#define kLenNumHighBits 8
  71#define kLenNumHighSymbols (1 << kLenNumHighBits)
  72
  73#define LenChoice 0
  74#define LenChoice2 (LenChoice + 1)
  75#define LenLow (LenChoice2 + 1)
  76#define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))
  77#define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))
  78#define kNumLenProbs (LenHigh + kLenNumHighSymbols)
  79
  80
  81#define kNumStates 12
  82#define kNumLitStates 7
  83
  84#define kStartPosModelIndex 4
  85#define kEndPosModelIndex 14
  86#define kNumFullDistances (1 << (kEndPosModelIndex >> 1))
  87
  88#define kNumPosSlotBits 6
  89#define kNumLenToPosStates 4
  90
  91#define kNumAlignBits 4
  92#define kAlignTableSize (1 << kNumAlignBits)
  93
  94#define kMatchMinLen 2
  95#define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols + kLenNumMidSymbols + kLenNumHighSymbols)
  96
  97#define IsMatch 0
  98#define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))
  99#define IsRepG0 (IsRep + kNumStates)
 100#define IsRepG1 (IsRepG0 + kNumStates)
 101#define IsRepG2 (IsRepG1 + kNumStates)
 102#define IsRep0Long (IsRepG2 + kNumStates)
 103#define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))
 104#define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
 105#define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)
 106#define LenCoder (Align + kAlignTableSize)
 107#define RepLenCoder (LenCoder + kNumLenProbs)
 108#define Literal (RepLenCoder + kNumLenProbs)
 109
 110#define LZMA_BASE_SIZE 1846
 111#define LZMA_LIT_SIZE 768
 112
 113#define LzmaProps_GetNumProbs(p) ((UInt32)LZMA_BASE_SIZE + (LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))
 114
 115#if Literal != LZMA_BASE_SIZE
 116StopCompilingDueBUG
 117#endif
 118
 119static const Byte kLiteralNextStates[kNumStates * 2] =
 120{
 121  0, 0, 0, 0, 1, 2, 3,  4,  5,  6,  4,  5,
 122  7, 7, 7, 7, 7, 7, 7, 10, 10, 10, 10, 10
 123};
 124
 125#define LZMA_DIC_MIN (1 << 12)
 126
 127/* First LZMA-symbol is always decoded.
 128And it decodes new LZMA-symbols while (buf < bufLimit), but "buf" is without last normalization
 129Out:
 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
 140static 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  WATCHDOG_RESET();
 163
 164  do
 165  {
 166    CLzmaProb *prob;
 167    UInt32 bound;
 168    unsigned ttt;
 169    unsigned posState = processedPos & pbMask;
 170
 171    prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
 172    IF_BIT_0(prob)
 173    {
 174      unsigned symbol;
 175      UPDATE_0(prob);
 176      prob = probs + Literal;
 177      if (checkDicSize != 0 || processedPos != 0)
 178        prob += (LZMA_LIT_SIZE * (((processedPos & lpMask) << lc) +
 179        (dic[(dicPos == 0 ? dicBufSize : dicPos) - 1] >> (8 - lc))));
 180
 181      if (state < kNumLitStates)
 182      {
 183        symbol = 1;
 184
 185        WATCHDOG_RESET();
 186
 187        do { GET_BIT(prob + symbol, symbol) } while (symbol < 0x100);
 188      }
 189      else
 190      {
 191        unsigned matchByte = p->dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 192        unsigned offs = 0x100;
 193        symbol = 1;
 194
 195        WATCHDOG_RESET();
 196
 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
 331              WATCHDOG_RESET();
 332
 333              do
 334              {
 335                GET_BIT2(prob + i, i, ; , distance |= mask);
 336                mask <<= 1;
 337              }
 338              while (--numDirectBits != 0);
 339            }
 340          }
 341          else
 342          {
 343            numDirectBits -= kNumAlignBits;
 344
 345            WATCHDOG_RESET();
 346
 347            do
 348            {
 349              NORMALIZE
 350              range >>= 1;
 351
 352              {
 353                UInt32 t;
 354                code -= range;
 355                t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */
 356                distance = (distance << 1) + (t + 1);
 357                code += range & t;
 358              }
 359              /*
 360              distance <<= 1;
 361              if (code >= range)
 362              {
 363                code -= range;
 364                distance |= 1;
 365              }
 366              */
 367            }
 368            while (--numDirectBits != 0);
 369            prob = probs + Align;
 370            distance <<= kNumAlignBits;
 371            {
 372              unsigned i = 1;
 373              GET_BIT2(prob + i, i, ; , distance |= 1);
 374              GET_BIT2(prob + i, i, ; , distance |= 2);
 375              GET_BIT2(prob + i, i, ; , distance |= 4);
 376              GET_BIT2(prob + i, i, ; , distance |= 8);
 377            }
 378            if (distance == (UInt32)0xFFFFFFFF)
 379            {
 380              len += kMatchSpecLenStart;
 381              state -= kNumStates;
 382              break;
 383            }
 384          }
 385        }
 386        rep3 = rep2;
 387        rep2 = rep1;
 388        rep1 = rep0;
 389        rep0 = distance + 1;
 390        if (checkDicSize == 0)
 391        {
 392          if (distance >= processedPos)
 393            return SZ_ERROR_DATA;
 394        }
 395        else if (distance >= checkDicSize)
 396          return SZ_ERROR_DATA;
 397        state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
 398        /* state = kLiteralNextStates[state]; */
 399      }
 400
 401      len += kMatchMinLen;
 402
 403      if (limit == dicPos)
 404        return SZ_ERROR_DATA;
 405      {
 406        SizeT rem = limit - dicPos;
 407        unsigned curLen = ((rem < len) ? (unsigned)rem : len);
 408        SizeT pos = (dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0);
 409
 410        processedPos += curLen;
 411
 412        len -= curLen;
 413        if (pos + curLen <= dicBufSize)
 414        {
 415          Byte *dest = dic + dicPos;
 416          ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;
 417          const Byte *lim = dest + curLen;
 418          dicPos += curLen;
 419
 420          WATCHDOG_RESET();
 421
 422          do
 423            *(dest) = (Byte)*(dest + src);
 424          while (++dest != lim);
 425        }
 426        else
 427        {
 428
 429          WATCHDOG_RESET();
 430
 431          do
 432          {
 433            dic[dicPos++] = dic[pos];
 434            if (++pos == dicBufSize)
 435              pos = 0;
 436          }
 437          while (--curLen != 0);
 438        }
 439      }
 440    }
 441  }
 442  while (dicPos < limit && buf < bufLimit);
 443
 444  WATCHDOG_RESET();
 445
 446  NORMALIZE;
 447  p->buf = buf;
 448  p->range = range;
 449  p->code = code;
 450  p->remainLen = len;
 451  p->dicPos = dicPos;
 452  p->processedPos = processedPos;
 453  p->reps[0] = rep0;
 454  p->reps[1] = rep1;
 455  p->reps[2] = rep2;
 456  p->reps[3] = rep3;
 457  p->state = state;
 458
 459  return SZ_OK;
 460}
 461
 462static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)
 463{
 464  if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)
 465  {
 466    Byte *dic = p->dic;
 467    SizeT dicPos = p->dicPos;
 468    SizeT dicBufSize = p->dicBufSize;
 469    unsigned len = p->remainLen;
 470    UInt32 rep0 = p->reps[0];
 471    if (limit - dicPos < len)
 472      len = (unsigned)(limit - dicPos);
 473
 474    if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
 475      p->checkDicSize = p->prop.dicSize;
 476
 477    p->processedPos += len;
 478    p->remainLen -= len;
 479    while (len-- != 0)
 480    {
 481      dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 482      dicPos++;
 483    }
 484    p->dicPos = dicPos;
 485  }
 486}
 487
 488static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
 489{
 490  do
 491  {
 492    SizeT limit2 = limit;
 493    if (p->checkDicSize == 0)
 494    {
 495      UInt32 rem = p->prop.dicSize - p->processedPos;
 496      if (limit - p->dicPos > rem)
 497        limit2 = p->dicPos + rem;
 498    }
 499    RINOK(LzmaDec_DecodeReal(p, limit2, bufLimit));
 500    if (p->processedPos >= p->prop.dicSize)
 501      p->checkDicSize = p->prop.dicSize;
 502    LzmaDec_WriteRem(p, limit);
 503  }
 504  while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);
 505
 506  if (p->remainLen > kMatchSpecLenStart)
 507  {
 508    p->remainLen = kMatchSpecLenStart;
 509  }
 510  return 0;
 511}
 512
 513typedef enum
 514{
 515  DUMMY_ERROR, /* unexpected end of input stream */
 516  DUMMY_LIT,
 517  DUMMY_MATCH,
 518  DUMMY_REP
 519} ELzmaDummy;
 520
 521static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)
 522{
 523  UInt32 range = p->range;
 524  UInt32 code = p->code;
 525  const Byte *bufLimit = buf + inSize;
 526  CLzmaProb *probs = p->probs;
 527  unsigned state = p->state;
 528  ELzmaDummy res;
 529
 530  {
 531    CLzmaProb *prob;
 532    UInt32 bound;
 533    unsigned ttt;
 534    unsigned posState = (p->processedPos) & ((1 << p->prop.pb) - 1);
 535
 536    prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
 537    IF_BIT_0_CHECK(prob)
 538    {
 539      UPDATE_0_CHECK
 540
 541      /* if (bufLimit - buf >= 7) return DUMMY_LIT; */
 542
 543      prob = probs + Literal;
 544      if (p->checkDicSize != 0 || p->processedPos != 0)
 545        prob += (LZMA_LIT_SIZE *
 546          ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +
 547          (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));
 548
 549      if (state < kNumLitStates)
 550      {
 551        unsigned symbol = 1;
 552        do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);
 553      }
 554      else
 555      {
 556        unsigned matchByte = p->dic[p->dicPos - p->reps[0] +
 557            ((p->dicPos < p->reps[0]) ? p->dicBufSize : 0)];
 558        unsigned offs = 0x100;
 559        unsigned symbol = 1;
 560        do
 561        {
 562          unsigned bit;
 563          CLzmaProb *probLit;
 564          matchByte <<= 1;
 565          bit = (matchByte & offs);
 566          probLit = prob + offs + bit + symbol;
 567          GET_BIT2_CHECK(probLit, symbol, offs &= ~bit, offs &= bit)
 568        }
 569        while (symbol < 0x100);
 570      }
 571      res = DUMMY_LIT;
 572    }
 573    else
 574    {
 575      unsigned len;
 576      UPDATE_1_CHECK;
 577
 578      prob = probs + IsRep + state;
 579      IF_BIT_0_CHECK(prob)
 580      {
 581        UPDATE_0_CHECK;
 582        state = 0;
 583        prob = probs + LenCoder;
 584        res = DUMMY_MATCH;
 585      }
 586      else
 587      {
 588        UPDATE_1_CHECK;
 589        res = DUMMY_REP;
 590        prob = probs + IsRepG0 + state;
 591        IF_BIT_0_CHECK(prob)
 592        {
 593          UPDATE_0_CHECK;
 594          prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
 595          IF_BIT_0_CHECK(prob)
 596          {
 597            UPDATE_0_CHECK;
 598            NORMALIZE_CHECK;
 599            return DUMMY_REP;
 600          }
 601          else
 602          {
 603            UPDATE_1_CHECK;
 604          }
 605        }
 606        else
 607        {
 608          UPDATE_1_CHECK;
 609          prob = probs + IsRepG1 + state;
 610          IF_BIT_0_CHECK(prob)
 611          {
 612            UPDATE_0_CHECK;
 613          }
 614          else
 615          {
 616            UPDATE_1_CHECK;
 617            prob = probs + IsRepG2 + state;
 618            IF_BIT_0_CHECK(prob)
 619            {
 620              UPDATE_0_CHECK;
 621            }
 622            else
 623            {
 624              UPDATE_1_CHECK;
 625            }
 626          }
 627        }
 628        state = kNumStates;
 629        prob = probs + RepLenCoder;
 630      }
 631      {
 632        unsigned limit, offset;
 633        CLzmaProb *probLen = prob + LenChoice;
 634        IF_BIT_0_CHECK(probLen)
 635        {
 636          UPDATE_0_CHECK;
 637          probLen = prob + LenLow + (posState << kLenNumLowBits);
 638          offset = 0;
 639          limit = 1 << kLenNumLowBits;
 640        }
 641        else
 642        {
 643          UPDATE_1_CHECK;
 644          probLen = prob + LenChoice2;
 645          IF_BIT_0_CHECK(probLen)
 646          {
 647            UPDATE_0_CHECK;
 648            probLen = prob + LenMid + (posState << kLenNumMidBits);
 649            offset = kLenNumLowSymbols;
 650            limit = 1 << kLenNumMidBits;
 651          }
 652          else
 653          {
 654            UPDATE_1_CHECK;
 655            probLen = prob + LenHigh;
 656            offset = kLenNumLowSymbols + kLenNumMidSymbols;
 657            limit = 1 << kLenNumHighBits;
 658          }
 659        }
 660        TREE_DECODE_CHECK(probLen, limit, len);
 661        len += offset;
 662      }
 663
 664      if (state < 4)
 665      {
 666        unsigned posSlot;
 667        prob = probs + PosSlot +
 668            ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) <<
 669            kNumPosSlotBits);
 670        TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
 671        if (posSlot >= kStartPosModelIndex)
 672        {
 673          int numDirectBits = ((posSlot >> 1) - 1);
 674
 675          /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */
 676
 677          if (posSlot < kEndPosModelIndex)
 678          {
 679            prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits) - posSlot - 1;
 680          }
 681          else
 682          {
 683            numDirectBits -= kNumAlignBits;
 684            do
 685            {
 686              NORMALIZE_CHECK
 687              range >>= 1;
 688              code -= range & (((code - range) >> 31) - 1);
 689              /* if (code >= range) code -= range; */
 690            }
 691            while (--numDirectBits != 0);
 692            prob = probs + Align;
 693            numDirectBits = kNumAlignBits;
 694          }
 695          {
 696            unsigned i = 1;
 697            do
 698            {
 699              GET_BIT_CHECK(prob + i, i);
 700            }
 701            while (--numDirectBits != 0);
 702          }
 703        }
 704      }
 705    }
 706  }
 707  NORMALIZE_CHECK;
 708  return res;
 709}
 710
 711
 712static void LzmaDec_InitRc(CLzmaDec *p, const Byte *data)
 713{
 714  p->code = ((UInt32)data[1] << 24) | ((UInt32)data[2] << 16) | ((UInt32)data[3] << 8) | ((UInt32)data[4]);
 715  p->range = 0xFFFFFFFF;
 716  p->needFlush = 0;
 717}
 718
 719void LzmaDec_InitDicAndState(CLzmaDec *p, Bool initDic, Bool initState)
 720{
 721  p->needFlush = 1;
 722  p->remainLen = 0;
 723  p->tempBufSize = 0;
 724
 725  if (initDic)
 726  {
 727    p->processedPos = 0;
 728    p->checkDicSize = 0;
 729    p->needInitState = 1;
 730  }
 731  if (initState)
 732    p->needInitState = 1;
 733}
 734
 735void LzmaDec_Init(CLzmaDec *p)
 736{
 737  p->dicPos = 0;
 738  LzmaDec_InitDicAndState(p, True, True);
 739}
 740
 741static void LzmaDec_InitStateReal(CLzmaDec *p)
 742{
 743  UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (p->prop.lc + p->prop.lp));
 744  UInt32 i;
 745  CLzmaProb *probs = p->probs;
 746  for (i = 0; i < numProbs; i++)
 747    probs[i] = kBitModelTotal >> 1;
 748  p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
 749  p->state = 0;
 750  p->needInitState = 0;
 751}
 752
 753SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen,
 754    ELzmaFinishMode finishMode, ELzmaStatus *status)
 755{
 756  SizeT inSize = *srcLen;
 757  (*srcLen) = 0;
 758  LzmaDec_WriteRem(p, dicLimit);
 759
 760  *status = LZMA_STATUS_NOT_SPECIFIED;
 761
 762  while (p->remainLen != kMatchSpecLenStart)
 763  {
 764      int checkEndMarkNow;
 765
 766      if (p->needFlush != 0)
 767      {
 768        for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
 769          p->tempBuf[p->tempBufSize++] = *src++;
 770        if (p->tempBufSize < RC_INIT_SIZE)
 771        {
 772          *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 773          return SZ_OK;
 774        }
 775        if (p->tempBuf[0] != 0)
 776          return SZ_ERROR_DATA;
 777
 778        LzmaDec_InitRc(p, p->tempBuf);
 779        p->tempBufSize = 0;
 780      }
 781
 782      checkEndMarkNow = 0;
 783      if (p->dicPos >= dicLimit)
 784      {
 785        if (p->remainLen == 0 && p->code == 0)
 786        {
 787          *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
 788          return SZ_OK;
 789        }
 790        if (finishMode == LZMA_FINISH_ANY)
 791        {
 792          *status = LZMA_STATUS_NOT_FINISHED;
 793          return SZ_OK;
 794        }
 795        if (p->remainLen != 0)
 796        {
 797          *status = LZMA_STATUS_NOT_FINISHED;
 798          return SZ_ERROR_DATA;
 799        }
 800        checkEndMarkNow = 1;
 801      }
 802
 803      if (p->needInitState)
 804        LzmaDec_InitStateReal(p);
 805
 806      if (p->tempBufSize == 0)
 807      {
 808        SizeT processed;
 809        const Byte *bufLimit;
 810        if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
 811        {
 812          int dummyRes = LzmaDec_TryDummy(p, src, inSize);
 813          if (dummyRes == DUMMY_ERROR)
 814          {
 815            memcpy(p->tempBuf, src, inSize);
 816            p->tempBufSize = (unsigned)inSize;
 817            (*srcLen) += inSize;
 818            *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 819            return SZ_OK;
 820          }
 821          if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
 822          {
 823            *status = LZMA_STATUS_NOT_FINISHED;
 824            return SZ_ERROR_DATA;
 825          }
 826          bufLimit = src;
 827        }
 828        else
 829          bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
 830        p->buf = src;
 831        if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
 832          return SZ_ERROR_DATA;
 833        processed = (SizeT)(p->buf - src);
 834        (*srcLen) += processed;
 835        src += processed;
 836        inSize -= processed;
 837      }
 838      else
 839      {
 840        unsigned rem = p->tempBufSize, lookAhead = 0;
 841        while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)
 842          p->tempBuf[rem++] = src[lookAhead++];
 843        p->tempBufSize = rem;
 844        if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
 845        {
 846          int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, rem);
 847          if (dummyRes == DUMMY_ERROR)
 848          {
 849            (*srcLen) += lookAhead;
 850            *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 851            return SZ_OK;
 852          }
 853          if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
 854          {
 855            *status = LZMA_STATUS_NOT_FINISHED;
 856            return SZ_ERROR_DATA;
 857          }
 858        }
 859        p->buf = p->tempBuf;
 860        if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
 861          return SZ_ERROR_DATA;
 862        lookAhead -= (rem - (unsigned)(p->buf - p->tempBuf));
 863        (*srcLen) += lookAhead;
 864        src += lookAhead;
 865        inSize -= lookAhead;
 866        p->tempBufSize = 0;
 867      }
 868  }
 869  if (p->code == 0)
 870    *status = LZMA_STATUS_FINISHED_WITH_MARK;
 871  return (p->code == 0) ? SZ_OK : SZ_ERROR_DATA;
 872}
 873
 874SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status)
 875{
 876  SizeT outSize = *destLen;
 877  SizeT inSize = *srcLen;
 878  *srcLen = *destLen = 0;
 879  for (;;)
 880  {
 881    SizeT inSizeCur = inSize, outSizeCur, dicPos;
 882    ELzmaFinishMode curFinishMode;
 883    SRes res;
 884    if (p->dicPos == p->dicBufSize)
 885      p->dicPos = 0;
 886    dicPos = p->dicPos;
 887    if (outSize > p->dicBufSize - dicPos)
 888    {
 889      outSizeCur = p->dicBufSize;
 890      curFinishMode = LZMA_FINISH_ANY;
 891    }
 892    else
 893    {
 894      outSizeCur = dicPos + outSize;
 895      curFinishMode = finishMode;
 896    }
 897
 898    res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
 899    src += inSizeCur;
 900    inSize -= inSizeCur;
 901    *srcLen += inSizeCur;
 902    outSizeCur = p->dicPos - dicPos;
 903    memcpy(dest, p->dic + dicPos, outSizeCur);
 904    dest += outSizeCur;
 905    outSize -= outSizeCur;
 906    *destLen += outSizeCur;
 907    if (res != 0)
 908      return res;
 909    if (outSizeCur == 0 || outSize == 0)
 910      return SZ_OK;
 911  }
 912}
 913
 914void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc)
 915{
 916  alloc->Free(alloc, p->probs);
 917  p->probs = 0;
 918}
 919
 920static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc)
 921{
 922  alloc->Free(alloc, p->dic);
 923  p->dic = 0;
 924}
 925
 926void LzmaDec_Free(CLzmaDec *p, ISzAlloc *alloc)
 927{
 928  LzmaDec_FreeProbs(p, alloc);
 929  LzmaDec_FreeDict(p, alloc);
 930}
 931
 932SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)
 933{
 934  UInt32 dicSize;
 935  Byte d;
 936
 937  if (size < LZMA_PROPS_SIZE)
 938    return SZ_ERROR_UNSUPPORTED;
 939  else
 940    dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);
 941
 942  if (dicSize < LZMA_DIC_MIN)
 943    dicSize = LZMA_DIC_MIN;
 944  p->dicSize = dicSize;
 945
 946  d = data[0];
 947  if (d >= (9 * 5 * 5))
 948    return SZ_ERROR_UNSUPPORTED;
 949
 950  p->lc = d % 9;
 951  d /= 9;
 952  p->pb = d / 5;
 953  p->lp = d % 5;
 954
 955  return SZ_OK;
 956}
 957
 958static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAlloc *alloc)
 959{
 960  UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
 961  if (p->probs == 0 || numProbs != p->numProbs)
 962  {
 963    LzmaDec_FreeProbs(p, alloc);
 964    p->probs = (CLzmaProb *)alloc->Alloc(alloc, numProbs * sizeof(CLzmaProb));
 965    p->numProbs = numProbs;
 966    if (p->probs == 0)
 967      return SZ_ERROR_MEM;
 968  }
 969  return SZ_OK;
 970}
 971
 972SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
 973{
 974  CLzmaProps propNew;
 975  RINOK(LzmaProps_Decode(&propNew, props, propsSize));
 976  RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
 977  p->prop = propNew;
 978  return SZ_OK;
 979}
 980
 981SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
 982{
 983  CLzmaProps propNew;
 984  SizeT dicBufSize;
 985  RINOK(LzmaProps_Decode(&propNew, props, propsSize));
 986  RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
 987  dicBufSize = propNew.dicSize;
 988  if (p->dic == 0 || dicBufSize != p->dicBufSize)
 989  {
 990    LzmaDec_FreeDict(p, alloc);
 991    p->dic = (Byte *)alloc->Alloc(alloc, dicBufSize);
 992    if (p->dic == 0)
 993    {
 994      LzmaDec_FreeProbs(p, alloc);
 995      return SZ_ERROR_MEM;
 996    }
 997  }
 998  p->dicBufSize = dicBufSize;
 999  p->prop = propNew;
1000  return SZ_OK;
1001}
1002
1003SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
1004    const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
1005    ELzmaStatus *status, ISzAlloc *alloc)
1006{
1007  CLzmaDec p;
1008  SRes res;
1009  SizeT inSize = *srcLen;
1010  SizeT outSize = *destLen;
1011  *srcLen = *destLen = 0;
1012  if (inSize < RC_INIT_SIZE)
1013    return SZ_ERROR_INPUT_EOF;
1014
1015  LzmaDec_Construct(&p);
1016  res = LzmaDec_AllocateProbs(&p, propData, propSize, alloc);
1017  if (res != 0)
1018    return res;
1019  p.dic = dest;
1020  p.dicBufSize = outSize;
1021
1022  LzmaDec_Init(&p);
1023
1024  *srcLen = inSize;
1025  res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);
1026
1027  if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
1028    res = SZ_ERROR_INPUT_EOF;
1029
1030  (*destLen) = p.dicPos;
1031  LzmaDec_FreeProbs(&p, alloc);
1032  return res;
1033}
1034