uboot/lib/lzma/LzmaDec.c
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   1/* LzmaDec.c -- LZMA Decoder
   22009-09-20 : 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
 119#define LZMA_DIC_MIN (1 << 12)
 120
 121/* First LZMA-symbol is always decoded.
 122And it decodes new LZMA-symbols while (buf < bufLimit), but "buf" is without last normalization
 123Out:
 124  Result:
 125    SZ_OK - OK
 126    SZ_ERROR_DATA - Error
 127  p->remainLen:
 128    < kMatchSpecLenStart : normal remain
 129    = kMatchSpecLenStart : finished
 130    = kMatchSpecLenStart + 1 : Flush marker
 131    = kMatchSpecLenStart + 2 : State Init Marker
 132*/
 133
 134static int MY_FAST_CALL LzmaDec_DecodeReal(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
 135{
 136  CLzmaProb *probs = p->probs;
 137
 138  unsigned state = p->state;
 139  UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];
 140  unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;
 141  unsigned lpMask = ((unsigned)1 << (p->prop.lp)) - 1;
 142  unsigned lc = p->prop.lc;
 143
 144  Byte *dic = p->dic;
 145  SizeT dicBufSize = p->dicBufSize;
 146  SizeT dicPos = p->dicPos;
 147
 148  UInt32 processedPos = p->processedPos;
 149  UInt32 checkDicSize = p->checkDicSize;
 150  unsigned len = 0;
 151
 152  const Byte *buf = p->buf;
 153  UInt32 range = p->range;
 154  UInt32 code = p->code;
 155
 156  WATCHDOG_RESET();
 157
 158  do
 159  {
 160    CLzmaProb *prob;
 161    UInt32 bound;
 162    unsigned ttt;
 163    unsigned posState = processedPos & pbMask;
 164
 165    prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
 166    IF_BIT_0(prob)
 167    {
 168      unsigned symbol;
 169      UPDATE_0(prob);
 170      prob = probs + Literal;
 171      if (checkDicSize != 0 || processedPos != 0)
 172        prob += (LZMA_LIT_SIZE * (((processedPos & lpMask) << lc) +
 173        (dic[(dicPos == 0 ? dicBufSize : dicPos) - 1] >> (8 - lc))));
 174
 175      if (state < kNumLitStates)
 176      {
 177        state -= (state < 4) ? state : 3;
 178        symbol = 1;
 179
 180        WATCHDOG_RESET();
 181
 182        do { GET_BIT(prob + symbol, symbol) } while (symbol < 0x100);
 183      }
 184      else
 185      {
 186        unsigned matchByte = p->dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 187        unsigned offs = 0x100;
 188        state -= (state < 10) ? 3 : 6;
 189        symbol = 1;
 190
 191        WATCHDOG_RESET();
 192
 193        do
 194        {
 195          unsigned bit;
 196          CLzmaProb *probLit;
 197          matchByte <<= 1;
 198          bit = (matchByte & offs);
 199          probLit = prob + offs + bit + symbol;
 200          GET_BIT2(probLit, symbol, offs &= ~bit, offs &= bit)
 201        }
 202        while (symbol < 0x100);
 203      }
 204      dic[dicPos++] = (Byte)symbol;
 205      processedPos++;
 206      continue;
 207    }
 208    else
 209    {
 210      UPDATE_1(prob);
 211      prob = probs + IsRep + state;
 212      IF_BIT_0(prob)
 213      {
 214        UPDATE_0(prob);
 215        state += kNumStates;
 216        prob = probs + LenCoder;
 217      }
 218      else
 219      {
 220        UPDATE_1(prob);
 221        if (checkDicSize == 0 && processedPos == 0)
 222          return SZ_ERROR_DATA;
 223        prob = probs + IsRepG0 + state;
 224        IF_BIT_0(prob)
 225        {
 226          UPDATE_0(prob);
 227          prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
 228          IF_BIT_0(prob)
 229          {
 230            UPDATE_0(prob);
 231            dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 232            dicPos++;
 233            processedPos++;
 234            state = state < kNumLitStates ? 9 : 11;
 235            continue;
 236          }
 237          UPDATE_1(prob);
 238        }
 239        else
 240        {
 241          UInt32 distance;
 242          UPDATE_1(prob);
 243          prob = probs + IsRepG1 + state;
 244          IF_BIT_0(prob)
 245          {
 246            UPDATE_0(prob);
 247            distance = rep1;
 248          }
 249          else
 250          {
 251            UPDATE_1(prob);
 252            prob = probs + IsRepG2 + state;
 253            IF_BIT_0(prob)
 254            {
 255              UPDATE_0(prob);
 256              distance = rep2;
 257            }
 258            else
 259            {
 260              UPDATE_1(prob);
 261              distance = rep3;
 262              rep3 = rep2;
 263            }
 264            rep2 = rep1;
 265          }
 266          rep1 = rep0;
 267          rep0 = distance;
 268        }
 269        state = state < kNumLitStates ? 8 : 11;
 270        prob = probs + RepLenCoder;
 271      }
 272      {
 273        unsigned limit, offset;
 274        CLzmaProb *probLen = prob + LenChoice;
 275        IF_BIT_0(probLen)
 276        {
 277          UPDATE_0(probLen);
 278          probLen = prob + LenLow + (posState << kLenNumLowBits);
 279          offset = 0;
 280          limit = (1 << kLenNumLowBits);
 281        }
 282        else
 283        {
 284          UPDATE_1(probLen);
 285          probLen = prob + LenChoice2;
 286          IF_BIT_0(probLen)
 287          {
 288            UPDATE_0(probLen);
 289            probLen = prob + LenMid + (posState << kLenNumMidBits);
 290            offset = kLenNumLowSymbols;
 291            limit = (1 << kLenNumMidBits);
 292          }
 293          else
 294          {
 295            UPDATE_1(probLen);
 296            probLen = prob + LenHigh;
 297            offset = kLenNumLowSymbols + kLenNumMidSymbols;
 298            limit = (1 << kLenNumHighBits);
 299          }
 300        }
 301        TREE_DECODE(probLen, limit, len);
 302        len += offset;
 303      }
 304
 305      if (state >= kNumStates)
 306      {
 307        UInt32 distance;
 308        prob = probs + PosSlot +
 309            ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
 310        TREE_6_DECODE(prob, distance);
 311        if (distance >= kStartPosModelIndex)
 312        {
 313          unsigned posSlot = (unsigned)distance;
 314          int numDirectBits = (int)(((distance >> 1) - 1));
 315          distance = (2 | (distance & 1));
 316          if (posSlot < kEndPosModelIndex)
 317          {
 318            distance <<= numDirectBits;
 319            prob = probs + SpecPos + distance - posSlot - 1;
 320            {
 321              UInt32 mask = 1;
 322              unsigned i = 1;
 323
 324              WATCHDOG_RESET();
 325
 326              do
 327              {
 328                GET_BIT2(prob + i, i, ; , distance |= mask);
 329                mask <<= 1;
 330              }
 331              while (--numDirectBits != 0);
 332            }
 333          }
 334          else
 335          {
 336            numDirectBits -= kNumAlignBits;
 337
 338            WATCHDOG_RESET();
 339
 340            do
 341            {
 342              NORMALIZE
 343              range >>= 1;
 344
 345              {
 346                UInt32 t;
 347                code -= range;
 348                t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */
 349                distance = (distance << 1) + (t + 1);
 350                code += range & t;
 351              }
 352              /*
 353              distance <<= 1;
 354              if (code >= range)
 355              {
 356                code -= range;
 357                distance |= 1;
 358              }
 359              */
 360            }
 361            while (--numDirectBits != 0);
 362            prob = probs + Align;
 363            distance <<= kNumAlignBits;
 364            {
 365              unsigned i = 1;
 366              GET_BIT2(prob + i, i, ; , distance |= 1);
 367              GET_BIT2(prob + i, i, ; , distance |= 2);
 368              GET_BIT2(prob + i, i, ; , distance |= 4);
 369              GET_BIT2(prob + i, i, ; , distance |= 8);
 370            }
 371            if (distance == (UInt32)0xFFFFFFFF)
 372            {
 373              len += kMatchSpecLenStart;
 374              state -= kNumStates;
 375              break;
 376            }
 377          }
 378        }
 379        rep3 = rep2;
 380        rep2 = rep1;
 381        rep1 = rep0;
 382        rep0 = distance + 1;
 383        if (checkDicSize == 0)
 384        {
 385          if (distance >= processedPos)
 386            return SZ_ERROR_DATA;
 387        }
 388        else if (distance >= checkDicSize)
 389          return SZ_ERROR_DATA;
 390        state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
 391      }
 392
 393      len += kMatchMinLen;
 394
 395      if (limit == dicPos)
 396        return SZ_ERROR_DATA;
 397      {
 398        SizeT rem = limit - dicPos;
 399        unsigned curLen = ((rem < len) ? (unsigned)rem : len);
 400        SizeT pos = (dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0);
 401
 402        processedPos += curLen;
 403
 404        len -= curLen;
 405        if (pos + curLen <= dicBufSize)
 406        {
 407          Byte *dest = dic + dicPos;
 408          ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;
 409          const Byte *lim = dest + curLen;
 410          dicPos += curLen;
 411
 412          WATCHDOG_RESET();
 413
 414          do
 415            *(dest) = (Byte)*(dest + src);
 416          while (++dest != lim);
 417        }
 418        else
 419        {
 420
 421          WATCHDOG_RESET();
 422
 423          do
 424          {
 425            dic[dicPos++] = dic[pos];
 426            if (++pos == dicBufSize)
 427              pos = 0;
 428          }
 429          while (--curLen != 0);
 430        }
 431      }
 432    }
 433  }
 434  while (dicPos < limit && buf < bufLimit);
 435
 436  WATCHDOG_RESET();
 437
 438  NORMALIZE;
 439  p->buf = buf;
 440  p->range = range;
 441  p->code = code;
 442  p->remainLen = len;
 443  p->dicPos = dicPos;
 444  p->processedPos = processedPos;
 445  p->reps[0] = rep0;
 446  p->reps[1] = rep1;
 447  p->reps[2] = rep2;
 448  p->reps[3] = rep3;
 449  p->state = state;
 450
 451  return SZ_OK;
 452}
 453
 454static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)
 455{
 456  if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)
 457  {
 458    Byte *dic = p->dic;
 459    SizeT dicPos = p->dicPos;
 460    SizeT dicBufSize = p->dicBufSize;
 461    unsigned len = p->remainLen;
 462    UInt32 rep0 = p->reps[0];
 463    if (limit - dicPos < len)
 464      len = (unsigned)(limit - dicPos);
 465
 466    if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
 467      p->checkDicSize = p->prop.dicSize;
 468
 469    p->processedPos += len;
 470    p->remainLen -= len;
 471    while (len-- != 0)
 472    {
 473      dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
 474      dicPos++;
 475    }
 476    p->dicPos = dicPos;
 477  }
 478}
 479
 480static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
 481{
 482  do
 483  {
 484    SizeT limit2 = limit;
 485    if (p->checkDicSize == 0)
 486    {
 487      UInt32 rem = p->prop.dicSize - p->processedPos;
 488      if (limit - p->dicPos > rem)
 489        limit2 = p->dicPos + rem;
 490    }
 491    RINOK(LzmaDec_DecodeReal(p, limit2, bufLimit));
 492    if (p->processedPos >= p->prop.dicSize)
 493      p->checkDicSize = p->prop.dicSize;
 494    LzmaDec_WriteRem(p, limit);
 495  }
 496  while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);
 497
 498  if (p->remainLen > kMatchSpecLenStart)
 499  {
 500    p->remainLen = kMatchSpecLenStart;
 501  }
 502  return 0;
 503}
 504
 505typedef enum
 506{
 507  DUMMY_ERROR, /* unexpected end of input stream */
 508  DUMMY_LIT,
 509  DUMMY_MATCH,
 510  DUMMY_REP
 511} ELzmaDummy;
 512
 513static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)
 514{
 515  UInt32 range = p->range;
 516  UInt32 code = p->code;
 517  const Byte *bufLimit = buf + inSize;
 518  CLzmaProb *probs = p->probs;
 519  unsigned state = p->state;
 520  ELzmaDummy res;
 521
 522  {
 523    CLzmaProb *prob;
 524    UInt32 bound;
 525    unsigned ttt;
 526    unsigned posState = (p->processedPos) & ((1 << p->prop.pb) - 1);
 527
 528    prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
 529    IF_BIT_0_CHECK(prob)
 530    {
 531      UPDATE_0_CHECK
 532
 533      /* if (bufLimit - buf >= 7) return DUMMY_LIT; */
 534
 535      prob = probs + Literal;
 536      if (p->checkDicSize != 0 || p->processedPos != 0)
 537        prob += (LZMA_LIT_SIZE *
 538          ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +
 539          (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));
 540
 541      if (state < kNumLitStates)
 542      {
 543        unsigned symbol = 1;
 544        do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);
 545      }
 546      else
 547      {
 548        unsigned matchByte = p->dic[p->dicPos - p->reps[0] +
 549            ((p->dicPos < p->reps[0]) ? p->dicBufSize : 0)];
 550        unsigned offs = 0x100;
 551        unsigned symbol = 1;
 552        do
 553        {
 554          unsigned bit;
 555          CLzmaProb *probLit;
 556          matchByte <<= 1;
 557          bit = (matchByte & offs);
 558          probLit = prob + offs + bit + symbol;
 559          GET_BIT2_CHECK(probLit, symbol, offs &= ~bit, offs &= bit)
 560        }
 561        while (symbol < 0x100);
 562      }
 563      res = DUMMY_LIT;
 564    }
 565    else
 566    {
 567      unsigned len;
 568      UPDATE_1_CHECK;
 569
 570      prob = probs + IsRep + state;
 571      IF_BIT_0_CHECK(prob)
 572      {
 573        UPDATE_0_CHECK;
 574        state = 0;
 575        prob = probs + LenCoder;
 576        res = DUMMY_MATCH;
 577      }
 578      else
 579      {
 580        UPDATE_1_CHECK;
 581        res = DUMMY_REP;
 582        prob = probs + IsRepG0 + state;
 583        IF_BIT_0_CHECK(prob)
 584        {
 585          UPDATE_0_CHECK;
 586          prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
 587          IF_BIT_0_CHECK(prob)
 588          {
 589            UPDATE_0_CHECK;
 590            NORMALIZE_CHECK;
 591            return DUMMY_REP;
 592          }
 593          else
 594          {
 595            UPDATE_1_CHECK;
 596          }
 597        }
 598        else
 599        {
 600          UPDATE_1_CHECK;
 601          prob = probs + IsRepG1 + state;
 602          IF_BIT_0_CHECK(prob)
 603          {
 604            UPDATE_0_CHECK;
 605          }
 606          else
 607          {
 608            UPDATE_1_CHECK;
 609            prob = probs + IsRepG2 + state;
 610            IF_BIT_0_CHECK(prob)
 611            {
 612              UPDATE_0_CHECK;
 613            }
 614            else
 615            {
 616              UPDATE_1_CHECK;
 617            }
 618          }
 619        }
 620        state = kNumStates;
 621        prob = probs + RepLenCoder;
 622      }
 623      {
 624        unsigned limit, offset;
 625        CLzmaProb *probLen = prob + LenChoice;
 626        IF_BIT_0_CHECK(probLen)
 627        {
 628          UPDATE_0_CHECK;
 629          probLen = prob + LenLow + (posState << kLenNumLowBits);
 630          offset = 0;
 631          limit = 1 << kLenNumLowBits;
 632        }
 633        else
 634        {
 635          UPDATE_1_CHECK;
 636          probLen = prob + LenChoice2;
 637          IF_BIT_0_CHECK(probLen)
 638          {
 639            UPDATE_0_CHECK;
 640            probLen = prob + LenMid + (posState << kLenNumMidBits);
 641            offset = kLenNumLowSymbols;
 642            limit = 1 << kLenNumMidBits;
 643          }
 644          else
 645          {
 646            UPDATE_1_CHECK;
 647            probLen = prob + LenHigh;
 648            offset = kLenNumLowSymbols + kLenNumMidSymbols;
 649            limit = 1 << kLenNumHighBits;
 650          }
 651        }
 652        TREE_DECODE_CHECK(probLen, limit, len);
 653        len += offset;
 654      }
 655
 656      if (state < 4)
 657      {
 658        unsigned posSlot;
 659        prob = probs + PosSlot +
 660            ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) <<
 661            kNumPosSlotBits);
 662        TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
 663        if (posSlot >= kStartPosModelIndex)
 664        {
 665          int numDirectBits = ((posSlot >> 1) - 1);
 666
 667          /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */
 668
 669          if (posSlot < kEndPosModelIndex)
 670          {
 671            prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits) - posSlot - 1;
 672          }
 673          else
 674          {
 675            numDirectBits -= kNumAlignBits;
 676            do
 677            {
 678              NORMALIZE_CHECK
 679              range >>= 1;
 680              code -= range & (((code - range) >> 31) - 1);
 681              /* if (code >= range) code -= range; */
 682            }
 683            while (--numDirectBits != 0);
 684            prob = probs + Align;
 685            numDirectBits = kNumAlignBits;
 686          }
 687          {
 688            unsigned i = 1;
 689            do
 690            {
 691              GET_BIT_CHECK(prob + i, i);
 692            }
 693            while (--numDirectBits != 0);
 694          }
 695        }
 696      }
 697    }
 698  }
 699  NORMALIZE_CHECK;
 700  return res;
 701}
 702
 703
 704static void LzmaDec_InitRc(CLzmaDec *p, const Byte *data)
 705{
 706  p->code = ((UInt32)data[1] << 24) | ((UInt32)data[2] << 16) | ((UInt32)data[3] << 8) | ((UInt32)data[4]);
 707  p->range = 0xFFFFFFFF;
 708  p->needFlush = 0;
 709}
 710
 711void LzmaDec_InitDicAndState(CLzmaDec *p, Bool initDic, Bool initState)
 712{
 713  p->needFlush = 1;
 714  p->remainLen = 0;
 715  p->tempBufSize = 0;
 716
 717  if (initDic)
 718  {
 719    p->processedPos = 0;
 720    p->checkDicSize = 0;
 721    p->needInitState = 1;
 722  }
 723  if (initState)
 724    p->needInitState = 1;
 725}
 726
 727void LzmaDec_Init(CLzmaDec *p)
 728{
 729  p->dicPos = 0;
 730  LzmaDec_InitDicAndState(p, True, True);
 731}
 732
 733static void LzmaDec_InitStateReal(CLzmaDec *p)
 734{
 735  UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (p->prop.lc + p->prop.lp));
 736  UInt32 i;
 737  CLzmaProb *probs = p->probs;
 738  for (i = 0; i < numProbs; i++)
 739    probs[i] = kBitModelTotal >> 1;
 740  p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
 741  p->state = 0;
 742  p->needInitState = 0;
 743}
 744
 745SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen,
 746    ELzmaFinishMode finishMode, ELzmaStatus *status)
 747{
 748  SizeT inSize = *srcLen;
 749  (*srcLen) = 0;
 750  LzmaDec_WriteRem(p, dicLimit);
 751
 752  *status = LZMA_STATUS_NOT_SPECIFIED;
 753
 754  while (p->remainLen != kMatchSpecLenStart)
 755  {
 756      int checkEndMarkNow;
 757
 758      if (p->needFlush != 0)
 759      {
 760        for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
 761          p->tempBuf[p->tempBufSize++] = *src++;
 762        if (p->tempBufSize < RC_INIT_SIZE)
 763        {
 764          *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 765          return SZ_OK;
 766        }
 767        if (p->tempBuf[0] != 0)
 768          return SZ_ERROR_DATA;
 769
 770        LzmaDec_InitRc(p, p->tempBuf);
 771        p->tempBufSize = 0;
 772      }
 773
 774      checkEndMarkNow = 0;
 775      if (p->dicPos >= dicLimit)
 776      {
 777        if (p->remainLen == 0 && p->code == 0)
 778        {
 779          *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
 780          return SZ_OK;
 781        }
 782        if (finishMode == LZMA_FINISH_ANY)
 783        {
 784          *status = LZMA_STATUS_NOT_FINISHED;
 785          return SZ_OK;
 786        }
 787        if (p->remainLen != 0)
 788        {
 789          *status = LZMA_STATUS_NOT_FINISHED;
 790          return SZ_ERROR_DATA;
 791        }
 792        checkEndMarkNow = 1;
 793      }
 794
 795      if (p->needInitState)
 796        LzmaDec_InitStateReal(p);
 797
 798      if (p->tempBufSize == 0)
 799      {
 800        SizeT processed;
 801        const Byte *bufLimit;
 802        if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
 803        {
 804          int dummyRes = LzmaDec_TryDummy(p, src, inSize);
 805          if (dummyRes == DUMMY_ERROR)
 806          {
 807            memcpy(p->tempBuf, src, inSize);
 808            p->tempBufSize = (unsigned)inSize;
 809            (*srcLen) += inSize;
 810            *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 811            return SZ_OK;
 812          }
 813          if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
 814          {
 815            *status = LZMA_STATUS_NOT_FINISHED;
 816            return SZ_ERROR_DATA;
 817          }
 818          bufLimit = src;
 819        }
 820        else
 821          bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
 822        p->buf = src;
 823        if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
 824          return SZ_ERROR_DATA;
 825        processed = (SizeT)(p->buf - src);
 826        (*srcLen) += processed;
 827        src += processed;
 828        inSize -= processed;
 829      }
 830      else
 831      {
 832        unsigned rem = p->tempBufSize, lookAhead = 0;
 833        while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)
 834          p->tempBuf[rem++] = src[lookAhead++];
 835        p->tempBufSize = rem;
 836        if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
 837        {
 838          int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, rem);
 839          if (dummyRes == DUMMY_ERROR)
 840          {
 841            (*srcLen) += lookAhead;
 842            *status = LZMA_STATUS_NEEDS_MORE_INPUT;
 843            return SZ_OK;
 844          }
 845          if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
 846          {
 847            *status = LZMA_STATUS_NOT_FINISHED;
 848            return SZ_ERROR_DATA;
 849          }
 850        }
 851        p->buf = p->tempBuf;
 852        if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
 853          return SZ_ERROR_DATA;
 854        lookAhead -= (rem - (unsigned)(p->buf - p->tempBuf));
 855        (*srcLen) += lookAhead;
 856        src += lookAhead;
 857        inSize -= lookAhead;
 858        p->tempBufSize = 0;
 859      }
 860  }
 861  if (p->code == 0)
 862    *status = LZMA_STATUS_FINISHED_WITH_MARK;
 863  return (p->code == 0) ? SZ_OK : SZ_ERROR_DATA;
 864}
 865
 866SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status)
 867{
 868  SizeT outSize = *destLen;
 869  SizeT inSize = *srcLen;
 870  *srcLen = *destLen = 0;
 871  for (;;)
 872  {
 873    SizeT inSizeCur = inSize, outSizeCur, dicPos;
 874    ELzmaFinishMode curFinishMode;
 875    SRes res;
 876    if (p->dicPos == p->dicBufSize)
 877      p->dicPos = 0;
 878    dicPos = p->dicPos;
 879    if (outSize > p->dicBufSize - dicPos)
 880    {
 881      outSizeCur = p->dicBufSize;
 882      curFinishMode = LZMA_FINISH_ANY;
 883    }
 884    else
 885    {
 886      outSizeCur = dicPos + outSize;
 887      curFinishMode = finishMode;
 888    }
 889
 890    res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
 891    src += inSizeCur;
 892    inSize -= inSizeCur;
 893    *srcLen += inSizeCur;
 894    outSizeCur = p->dicPos - dicPos;
 895    memcpy(dest, p->dic + dicPos, outSizeCur);
 896    dest += outSizeCur;
 897    outSize -= outSizeCur;
 898    *destLen += outSizeCur;
 899    if (res != 0)
 900      return res;
 901    if (outSizeCur == 0 || outSize == 0)
 902      return SZ_OK;
 903  }
 904}
 905
 906void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc)
 907{
 908  alloc->Free(alloc, p->probs);
 909  p->probs = 0;
 910}
 911
 912static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc)
 913{
 914  alloc->Free(alloc, p->dic);
 915  p->dic = 0;
 916}
 917
 918void LzmaDec_Free(CLzmaDec *p, ISzAlloc *alloc)
 919{
 920  LzmaDec_FreeProbs(p, alloc);
 921  LzmaDec_FreeDict(p, alloc);
 922}
 923
 924SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)
 925{
 926  UInt32 dicSize;
 927  Byte d;
 928
 929  if (size < LZMA_PROPS_SIZE)
 930    return SZ_ERROR_UNSUPPORTED;
 931  else
 932    dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);
 933
 934  if (dicSize < LZMA_DIC_MIN)
 935    dicSize = LZMA_DIC_MIN;
 936  p->dicSize = dicSize;
 937
 938  d = data[0];
 939  if (d >= (9 * 5 * 5))
 940    return SZ_ERROR_UNSUPPORTED;
 941
 942  p->lc = d % 9;
 943  d /= 9;
 944  p->pb = d / 5;
 945  p->lp = d % 5;
 946
 947  return SZ_OK;
 948}
 949
 950static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAlloc *alloc)
 951{
 952  UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
 953  if (p->probs == 0 || numProbs != p->numProbs)
 954  {
 955    LzmaDec_FreeProbs(p, alloc);
 956    p->probs = (CLzmaProb *)alloc->Alloc(alloc, numProbs * sizeof(CLzmaProb));
 957    p->numProbs = numProbs;
 958    if (p->probs == 0)
 959      return SZ_ERROR_MEM;
 960  }
 961  return SZ_OK;
 962}
 963
 964SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
 965{
 966  CLzmaProps propNew;
 967  RINOK(LzmaProps_Decode(&propNew, props, propsSize));
 968  RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
 969  p->prop = propNew;
 970  return SZ_OK;
 971}
 972
 973SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
 974{
 975  CLzmaProps propNew;
 976  SizeT dicBufSize;
 977  RINOK(LzmaProps_Decode(&propNew, props, propsSize));
 978  RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
 979  dicBufSize = propNew.dicSize;
 980  if (p->dic == 0 || dicBufSize != p->dicBufSize)
 981  {
 982    LzmaDec_FreeDict(p, alloc);
 983    p->dic = (Byte *)alloc->Alloc(alloc, dicBufSize);
 984    if (p->dic == 0)
 985    {
 986      LzmaDec_FreeProbs(p, alloc);
 987      return SZ_ERROR_MEM;
 988    }
 989  }
 990  p->dicBufSize = dicBufSize;
 991  p->prop = propNew;
 992  return SZ_OK;
 993}
 994
 995SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
 996    const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
 997    ELzmaStatus *status, ISzAlloc *alloc)
 998{
 999  CLzmaDec p;
1000  SRes res;
1001  SizeT inSize = *srcLen;
1002  SizeT outSize = *destLen;
1003  *srcLen = *destLen = 0;
1004  if (inSize < RC_INIT_SIZE)
1005    return SZ_ERROR_INPUT_EOF;
1006
1007  LzmaDec_Construct(&p);
1008  res = LzmaDec_AllocateProbs(&p, propData, propSize, alloc);
1009  if (res != 0)
1010    return res;
1011  p.dic = dest;
1012  p.dicBufSize = outSize;
1013
1014  LzmaDec_Init(&p);
1015
1016  *srcLen = inSize;
1017  res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);
1018
1019  if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
1020    res = SZ_ERROR_INPUT_EOF;
1021
1022  (*destLen) = p.dicPos;
1023  LzmaDec_FreeProbs(&p, alloc);
1024  return res;
1025}
1026