LzmaDec.cc

Go to the documentation of this file.

/* LzmaDec.c -- LZMA Decoder
2009-09-20 : Igor Pavlov : Public domain */

#include "LzmaDec.h"

#include <cstring>

#define kNumTopBits 24
#define kTopValue ((UInt32)1 << kNumTopBits)

#define kNumBitModelTotalBits 11
#define kBitModelTotal (1 << kNumBitModelTotalBits)
#define kNumMoveBits 5

#define RC_INIT_SIZE 5

#define NORMALIZE                  \
  if (range < kTopValue) {         \
    range <<= 8;                   \
    code = (code << 8) | (*buf++); \
  }

#define IF_BIT_0(p)                               \
  ttt = *(p);                                     \
  NORMALIZE;                                      \
  bound = (range >> kNumBitModelTotalBits) * ttt; \
  if (code < bound)
#define UPDATE_0(p) \
  range = bound;    \
  *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
#define UPDATE_1(p) \
  range -= bound;   \
  code -= bound;    \
  *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
#define GET_BIT2(p, i, A0, A1) \
  IF_BIT_0(p) {                \
    UPDATE_0(p);               \
    i = (i + i);               \
    A0;                        \
  }                            \
  else {                       \
    UPDATE_1(p);               \
    i = (i + i) + 1;           \
    A1;                        \
  }
#define GET_BIT(p, i) GET_BIT2(p, i, ;, ;)

#define TREE_GET_BIT(probs, i) \
  { GET_BIT((probs + i), i); }
#define TREE_DECODE(probs, limit, i) \
  {                                  \
    i = 1;                           \
    do {                             \
      TREE_GET_BIT(probs, i);        \
    } while (i < limit);             \
    i -= limit;                      \
  }

/* #define _LZMA_SIZE_OPT */

#ifdef _LZMA_SIZE_OPT
#define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
#else
#define TREE_6_DECODE(probs, i) \
  {                             \
    i = 1;                      \
    TREE_GET_BIT(probs, i);     \
    TREE_GET_BIT(probs, i);     \
    TREE_GET_BIT(probs, i);     \
    TREE_GET_BIT(probs, i);     \
    TREE_GET_BIT(probs, i);     \
    TREE_GET_BIT(probs, i);     \
    i -= 0x40;                  \
  }
#endif

#define NORMALIZE_CHECK            \
  if (range < kTopValue) {         \
    if (buf >= bufLimit)           \
      return DUMMY_ERROR;          \
    range <<= 8;                   \
    code = (code << 8) | (*buf++); \
  }

#define IF_BIT_0_CHECK(p)                         \
  ttt = *(p);                                     \
  NORMALIZE_CHECK;                                \
  bound = (range >> kNumBitModelTotalBits) * ttt; \
  if (code < bound)
#define UPDATE_0_CHECK range = bound;
#define UPDATE_1_CHECK \
  range -= bound;      \
  code -= bound;
#define GET_BIT2_CHECK(p, i, A0, A1) \
  IF_BIT_0_CHECK(p) {                \
    UPDATE_0_CHECK;                  \
    i = (i + i);                     \
    A0;                              \
  }                                  \
  else {                             \
    UPDATE_1_CHECK;                  \
    i = (i + i) + 1;                 \
    A1;                              \
  }
#define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ;, ;)
#define TREE_DECODE_CHECK(probs, limit, i) \
  {                                        \
    i = 1;                                 \
    do {                                   \
      GET_BIT_CHECK(probs + i, i)          \
    } while (i < limit);                   \
    i -= limit;                            \
  }

#define kNumPosBitsMax 4
#define kNumPosStatesMax (1 << kNumPosBitsMax)

#define kLenNumLowBits 3
#define kLenNumLowSymbols (1 << kLenNumLowBits)
#define kLenNumMidBits 3
#define kLenNumMidSymbols (1 << kLenNumMidBits)
#define kLenNumHighBits 8
#define kLenNumHighSymbols (1 << kLenNumHighBits)

#define LenChoice 0
#define LenChoice2 (LenChoice + 1)
#define LenLow (LenChoice2 + 1)
#define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))
#define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))
#define kNumLenProbs (LenHigh + kLenNumHighSymbols)

#define kNumStates 12
#define kNumLitStates 7

#define kStartPosModelIndex 4
#define kEndPosModelIndex 14
#define kNumFullDistances (1 << (kEndPosModelIndex >> 1))

#define kNumPosSlotBits 6
#define kNumLenToPosStates 4

#define kNumAlignBits 4
#define kAlignTableSize (1 << kNumAlignBits)

#define kMatchMinLen 2
#define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols + kLenNumMidSymbols + kLenNumHighSymbols)

#define IsMatch 0
#define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))
#define IsRepG0 (IsRep + kNumStates)
#define IsRepG1 (IsRepG0 + kNumStates)
#define IsRepG2 (IsRepG1 + kNumStates)
#define IsRep0Long (IsRepG2 + kNumStates)
#define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))
#define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
#define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)
#define LenCoder (Align + kAlignTableSize)
#define RepLenCoder (LenCoder + kNumLenProbs)
#define Literal (RepLenCoder + kNumLenProbs)

#define LZMA_BASE_SIZE 1846
#define LZMA_LIT_SIZE 768

#define LzmaProps_GetNumProbs(p) ((UInt32)LZMA_BASE_SIZE + (LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))

#if Literal != LZMA_BASE_SIZE
StopCompilingDueBUG
#endif

#define LZMA_DIC_MIN (1 << 12)

    /* First LZMA-symbol is always decoded.
And it decodes new LZMA-symbols while (buf < bufLimit), but "buf" is without last normalization
Out:
  Result:
    SZ_OK - OK
    SZ_ERROR_DATA - Error
  p->remainLen:
    < kMatchSpecLenStart : normal remain
    = kMatchSpecLenStart : finished
    = kMatchSpecLenStart + 1 : Flush marker
    = kMatchSpecLenStart + 2 : State Init Marker
*/

    static int MY_FAST_CALL
    LzmaDec_DecodeReal(CLzmaDec *p, SizeT limit, const Byte *bufLimit) {
  CLzmaProb *probs = p->probs;

  unsigned state = p->state;
  UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];
  unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;
  unsigned lpMask = ((unsigned)1 << (p->prop.lp)) - 1;
  unsigned lc = p->prop.lc;

  Byte *dic = p->dic;
  SizeT dicBufSize = p->dicBufSize;
  SizeT dicPos = p->dicPos;

  UInt32 processedPos = p->processedPos;
  UInt32 checkDicSize = p->checkDicSize;
  unsigned len = 0;

  const Byte *buf = p->buf;
  UInt32 range = p->range;
  UInt32 code = p->code;

  do {
    CLzmaProb *prob;
    UInt32 bound;
    unsigned ttt;
    unsigned posState = processedPos & pbMask;

    prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
    IF_BIT_0(prob) {
      unsigned symbol;
      UPDATE_0(prob);
      prob = probs + Literal;
      if (checkDicSize != 0 || processedPos != 0)
        prob += (LZMA_LIT_SIZE *
                 (((processedPos & lpMask) << lc) + (dic[(dicPos == 0 ? dicBufSize : dicPos) - 1] >> (8 - lc))));

      if (state < kNumLitStates) {
        state -= (state < 4) ? state : 3;
        symbol = 1;
        do {
          GET_BIT(prob + symbol, symbol)
        } while (symbol < 0x100);
      } else {
        unsigned matchByte = p->dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
        unsigned offs = 0x100;
        state -= (state < 10) ? 3 : 6;
        symbol = 1;
        do {
          unsigned bit;
          CLzmaProb *probLit;
          matchByte <<= 1;
          bit = (matchByte & offs);
          probLit = prob + offs + bit + symbol;
          GET_BIT2(probLit, symbol, offs &= ~bit, offs &= bit)
        } while (symbol < 0x100);
      }
      dic[dicPos++] = (Byte)symbol;
      processedPos++;
      continue;
    }
    else {
      UPDATE_1(prob);
      prob = probs + IsRep + state;
      IF_BIT_0(prob) {
        UPDATE_0(prob);
        state += kNumStates;
        prob = probs + LenCoder;
      }
      else {
        UPDATE_1(prob);
        if (checkDicSize == 0 && processedPos == 0)
          return SZ_ERROR_DATA;
        prob = probs + IsRepG0 + state;
        IF_BIT_0(prob) {
          UPDATE_0(prob);
          prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
          IF_BIT_0(prob) {
            UPDATE_0(prob);
            dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
            dicPos++;
            processedPos++;
            state = state < kNumLitStates ? 9 : 11;
            continue;
          }
          UPDATE_1(prob);
        }
        else {
          UInt32 distance;
          UPDATE_1(prob);
          prob = probs + IsRepG1 + state;
          IF_BIT_0(prob) {
            UPDATE_0(prob);
            distance = rep1;
          }
          else {
            UPDATE_1(prob);
            prob = probs + IsRepG2 + state;
            IF_BIT_0(prob) {
              UPDATE_0(prob);
              distance = rep2;
            }
            else {
              UPDATE_1(prob);
              distance = rep3;
              rep3 = rep2;
            }
            rep2 = rep1;
          }
          rep1 = rep0;
          rep0 = distance;
        }
        state = state < kNumLitStates ? 8 : 11;
        prob = probs + RepLenCoder;
      }
      {
        unsigned limit, offset;
        CLzmaProb *probLen = prob + LenChoice;
        IF_BIT_0(probLen) {
          UPDATE_0(probLen);
          probLen = prob + LenLow + (posState << kLenNumLowBits);
          offset = 0;
          limit = (1 << kLenNumLowBits);
        }
        else {
          UPDATE_1(probLen);
          probLen = prob + LenChoice2;
          IF_BIT_0(probLen) {
            UPDATE_0(probLen);
            probLen = prob + LenMid + (posState << kLenNumMidBits);
            offset = kLenNumLowSymbols;
            limit = (1 << kLenNumMidBits);
          }
          else {
            UPDATE_1(probLen);
            probLen = prob + LenHigh;
            offset = kLenNumLowSymbols + kLenNumMidSymbols;
            limit = (1 << kLenNumHighBits);
          }
        }
        TREE_DECODE(probLen, limit, len);
        len += offset;
      }

      if (state >= kNumStates) {
        UInt32 distance;
        prob = probs + PosSlot + ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
        TREE_6_DECODE(prob, distance);
        if (distance >= kStartPosModelIndex) {
          unsigned posSlot = (unsigned)distance;
          int numDirectBits = (int)(((distance >> 1) - 1));
          distance = (2 | (distance & 1));
          if (posSlot < kEndPosModelIndex) {
            distance <<= numDirectBits;
            prob = probs + SpecPos + distance - posSlot - 1;
            {
              UInt32 mask = 1;
              unsigned i = 1;
              do {
                GET_BIT2(prob + i, i, ;, distance |= mask);
                mask <<= 1;
              } while (--numDirectBits != 0);
            }
          } else {
            numDirectBits -= kNumAlignBits;
            do {
              NORMALIZE
              range >>= 1;

              {
                UInt32 t;
                code -= range;
                t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */
                distance = (distance << 1) + (t + 1);
                code += range & t;
              }
              /*
              distance <<= 1;
              if (code >= range)
              {
                code -= range;
                distance |= 1;
              }
              */
            } while (--numDirectBits != 0);
            prob = probs + Align;
            distance <<= kNumAlignBits;
            {
              unsigned i = 1;
              GET_BIT2(prob + i, i, ;, distance |= 1);
              GET_BIT2(prob + i, i, ;, distance |= 2);
              GET_BIT2(prob + i, i, ;, distance |= 4);
              GET_BIT2(prob + i, i, ;, distance |= 8);
            }
            if (distance == (UInt32)0xFFFFFFFF) {
              len += kMatchSpecLenStart;
              state -= kNumStates;
              break;
            }
          }
        }
        rep3 = rep2;
        rep2 = rep1;
        rep1 = rep0;
        rep0 = distance + 1;
        if (checkDicSize == 0) {
          if (distance >= processedPos)
            return SZ_ERROR_DATA;
        } else if (distance >= checkDicSize)
          return SZ_ERROR_DATA;
        state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
      }

      len += kMatchMinLen;

      if (limit == dicPos)
        return SZ_ERROR_DATA;
      {
        SizeT rem = limit - dicPos;
        unsigned curLen = ((rem < len) ? (unsigned)rem : len);
        SizeT pos = (dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0);

        processedPos += curLen;

        len -= curLen;
        if (pos + curLen <= dicBufSize) {
          Byte *dest = dic + dicPos;
          ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;
          const Byte *lim = dest + curLen;
          dicPos += curLen;
          do
            *(dest) = (Byte) * (dest + src);
          while (++dest != lim);
        } else {
          do {
            dic[dicPos++] = dic[pos];
            if (++pos == dicBufSize)
              pos = 0;
          } while (--curLen != 0);
        }
      }
    }
  } while (dicPos < limit && buf < bufLimit);
  NORMALIZE;
  p->buf = buf;
  p->range = range;
  p->code = code;
  p->remainLen = len;
  p->dicPos = dicPos;
  p->processedPos = processedPos;
  p->reps[0] = rep0;
  p->reps[1] = rep1;
  p->reps[2] = rep2;
  p->reps[3] = rep3;
  p->state = state;

  return SZ_OK;
}

static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit) {
  if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart) {
    Byte *dic = p->dic;
    SizeT dicPos = p->dicPos;
    SizeT dicBufSize = p->dicBufSize;
    unsigned len = p->remainLen;
    UInt32 rep0 = p->reps[0];
    if (limit - dicPos < len)
      len = (unsigned)(limit - dicPos);

    if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
      p->checkDicSize = p->prop.dicSize;

    p->processedPos += len;
    p->remainLen -= len;
    while (len-- != 0) {
      dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
      dicPos++;
    }
    p->dicPos = dicPos;
  }
}

static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit) {
  do {
    SizeT limit2 = limit;
    if (p->checkDicSize == 0) {
      UInt32 rem = p->prop.dicSize - p->processedPos;
      if (limit - p->dicPos > rem)
        limit2 = p->dicPos + rem;
    }
    RINOK(LzmaDec_DecodeReal(p, limit2, bufLimit));
    if (p->processedPos >= p->prop.dicSize)
      p->checkDicSize = p->prop.dicSize;
    LzmaDec_WriteRem(p, limit);
  } while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);

  if (p->remainLen > kMatchSpecLenStart) {
    p->remainLen = kMatchSpecLenStart;
  }
  return 0;
}

typedef enum {
  DUMMY_ERROR, /* unexpected end of input stream */
  DUMMY_LIT,
  DUMMY_MATCH,
  DUMMY_REP
} ELzmaDummy;

static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize) {
  UInt32 range = p->range;
  UInt32 code = p->code;
  const Byte *bufLimit = buf + inSize;
  CLzmaProb *probs = p->probs;
  unsigned state = p->state;
  ELzmaDummy res;

  {
    CLzmaProb *prob;
    UInt32 bound;
    unsigned ttt;
    unsigned posState = (p->processedPos) & ((1 << p->prop.pb) - 1);

    prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
    IF_BIT_0_CHECK(prob) {
      UPDATE_0_CHECK

      /* if (bufLimit - buf >= 7) return DUMMY_LIT; */

      prob = probs + Literal;
      if (p->checkDicSize != 0 || p->processedPos != 0)
        prob += (LZMA_LIT_SIZE * ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +
                                  (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));

      if (state < kNumLitStates) {
        unsigned symbol = 1;
        do {
          GET_BIT_CHECK(prob + symbol, symbol)
        } while (symbol < 0x100);
      } else {
        unsigned matchByte = p->dic[p->dicPos - p->reps[0] + ((p->dicPos < p->reps[0]) ? p->dicBufSize : 0)];
        unsigned offs = 0x100;
        unsigned symbol = 1;
        do {
          unsigned bit;
          CLzmaProb *probLit;
          matchByte <<= 1;
          bit = (matchByte & offs);
          probLit = prob + offs + bit + symbol;
          GET_BIT2_CHECK(probLit, symbol, offs &= ~bit, offs &= bit)
        } while (symbol < 0x100);
      }
      res = DUMMY_LIT;
    }
    else {
      unsigned len;
      UPDATE_1_CHECK;

      prob = probs + IsRep + state;
      IF_BIT_0_CHECK(prob) {
        UPDATE_0_CHECK;
        state = 0;
        prob = probs + LenCoder;
        res = DUMMY_MATCH;
      }
      else {
        UPDATE_1_CHECK;
        res = DUMMY_REP;
        prob = probs + IsRepG0 + state;
        IF_BIT_0_CHECK(prob) {
          UPDATE_0_CHECK;
          prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
          IF_BIT_0_CHECK(prob) {
            UPDATE_0_CHECK;
            NORMALIZE_CHECK;
            return DUMMY_REP;
          }
          else {
            UPDATE_1_CHECK;
          }
        }
        else {
          UPDATE_1_CHECK;
          prob = probs + IsRepG1 + state;
          IF_BIT_0_CHECK(prob) { UPDATE_0_CHECK; }
          else {
            UPDATE_1_CHECK;
            prob = probs + IsRepG2 + state;
            IF_BIT_0_CHECK(prob) { UPDATE_0_CHECK; }
            else {
              UPDATE_1_CHECK;
            }
          }
        }
        state = kNumStates;
        prob = probs + RepLenCoder;
      }
      {
        unsigned limit, offset;
        CLzmaProb *probLen = prob + LenChoice;
        IF_BIT_0_CHECK(probLen) {
          UPDATE_0_CHECK;
          probLen = prob + LenLow + (posState << kLenNumLowBits);
          offset = 0;
          limit = 1 << kLenNumLowBits;
        }
        else {
          UPDATE_1_CHECK;
          probLen = prob + LenChoice2;
          IF_BIT_0_CHECK(probLen) {
            UPDATE_0_CHECK;
            probLen = prob + LenMid + (posState << kLenNumMidBits);
            offset = kLenNumLowSymbols;
            limit = 1 << kLenNumMidBits;
          }
          else {
            UPDATE_1_CHECK;
            probLen = prob + LenHigh;
            offset = kLenNumLowSymbols + kLenNumMidSymbols;
            limit = 1 << kLenNumHighBits;
          }
        }
        TREE_DECODE_CHECK(probLen, limit, len);
        len += offset;
      }

      if (state < 4) {
        unsigned posSlot;
        prob = probs + PosSlot + ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
        TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
        if (posSlot >= kStartPosModelIndex) {
          int numDirectBits = ((posSlot >> 1) - 1);

          /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */

          if (posSlot < kEndPosModelIndex) {
            prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits) - posSlot - 1;
          } else {
            numDirectBits -= kNumAlignBits;
            do {
              NORMALIZE_CHECK
              range >>= 1;
              code -= range & (((code - range) >> 31) - 1);
              /* if (code >= range) code -= range; */
            } while (--numDirectBits != 0);
            prob = probs + Align;
            numDirectBits = kNumAlignBits;
          }
          {
            unsigned i = 1;
            do {
              GET_BIT_CHECK(prob + i, i);
            } while (--numDirectBits != 0);
          }
        }
      }
    }
  }
  NORMALIZE_CHECK;
  return res;
}

static void LzmaDec_InitRc(CLzmaDec *p, const Byte *data) {
  p->code = ((UInt32)data[1] << 24) | ((UInt32)data[2] << 16) | ((UInt32)data[3] << 8) | ((UInt32)data[4]);
  p->range = 0xFFFFFFFF;
  p->needFlush = 0;
}

void LzmaDec_InitDicAndState(CLzmaDec *p, Bool initDic, Bool initState) {
  p->needFlush = 1;
  p->remainLen = 0;
  p->tempBufSize = 0;

  if (initDic) {
    p->processedPos = 0;
    p->checkDicSize = 0;
    p->needInitState = 1;
  }
  if (initState)
    p->needInitState = 1;
}

void LzmaDec_Init(CLzmaDec *p) {
  p->dicPos = 0;
  LzmaDec_InitDicAndState(p, True, True);
}

static void LzmaDec_InitStateReal(CLzmaDec *p) {
  UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (p->prop.lc + p->prop.lp));
  UInt32 i;
  CLzmaProb *probs = p->probs;
  for (i = 0; i < numProbs; i++)
    probs[i] = kBitModelTotal >> 1;
  p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
  p->state = 0;
  p->needInitState = 0;
}

SRes LzmaDec_DecodeToDic(
    CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status) {
  SizeT inSize = *srcLen;
  (*srcLen) = 0;
  LzmaDec_WriteRem(p, dicLimit);

  *status = LZMA_STATUS_NOT_SPECIFIED;

  while (p->remainLen != kMatchSpecLenStart) {
    int checkEndMarkNow;

    if (p->needFlush != 0) {
      for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
        p->tempBuf[p->tempBufSize++] = *src++;
      if (p->tempBufSize < RC_INIT_SIZE) {
        *status = LZMA_STATUS_NEEDS_MORE_INPUT;
        return SZ_OK;
      }
      if (p->tempBuf[0] != 0)
        return SZ_ERROR_DATA;

      LzmaDec_InitRc(p, p->tempBuf);
      p->tempBufSize = 0;
    }

    checkEndMarkNow = 0;
    if (p->dicPos >= dicLimit) {
      if (p->remainLen == 0 && p->code == 0) {
        *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
        return SZ_OK;
      }
      if (finishMode == LZMA_FINISH_ANY) {
        *status = LZMA_STATUS_NOT_FINISHED;
        return SZ_OK;
      }
      if (p->remainLen != 0) {
        *status = LZMA_STATUS_NOT_FINISHED;
        return SZ_ERROR_DATA;
      }
      checkEndMarkNow = 1;
    }

    if (p->needInitState)
      LzmaDec_InitStateReal(p);

    if (p->tempBufSize == 0) {
      SizeT processed;
      const Byte *bufLimit;
      if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow) {
        int dummyRes = LzmaDec_TryDummy(p, src, inSize);
        if (dummyRes == DUMMY_ERROR) {
          memcpy(p->tempBuf, src, inSize);
          p->tempBufSize = (unsigned)inSize;
          (*srcLen) += inSize;
          *status = LZMA_STATUS_NEEDS_MORE_INPUT;
          return SZ_OK;
        }
        if (checkEndMarkNow && dummyRes != DUMMY_MATCH) {
          *status = LZMA_STATUS_NOT_FINISHED;
          return SZ_ERROR_DATA;
        }
        bufLimit = src;
      } else
        bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
      p->buf = src;
      if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
        return SZ_ERROR_DATA;
      processed = (SizeT)(p->buf - src);
      (*srcLen) += processed;
      src += processed;
      inSize -= processed;
    } else {
      unsigned rem = p->tempBufSize, lookAhead = 0;
      while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)
        p->tempBuf[rem++] = src[lookAhead++];
      p->tempBufSize = rem;
      if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow) {
        int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, rem);
        if (dummyRes == DUMMY_ERROR) {
          (*srcLen) += lookAhead;
          *status = LZMA_STATUS_NEEDS_MORE_INPUT;
          return SZ_OK;
        }
        if (checkEndMarkNow && dummyRes != DUMMY_MATCH) {
          *status = LZMA_STATUS_NOT_FINISHED;
          return SZ_ERROR_DATA;
        }
      }
      p->buf = p->tempBuf;
      if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
        return SZ_ERROR_DATA;
      lookAhead -= (rem - (unsigned)(p->buf - p->tempBuf));
      (*srcLen) += lookAhead;
      src += lookAhead;
      inSize -= lookAhead;
      p->tempBufSize = 0;
    }
  }
  if (p->code == 0)
    *status = LZMA_STATUS_FINISHED_WITH_MARK;
  return (p->code == 0) ? SZ_OK : SZ_ERROR_DATA;
}

SRes LzmaDec_DecodeToBuf(CLzmaDec *p,
                         Byte *dest,
                         SizeT *destLen,
                         const Byte *src,
                         SizeT *srcLen,
                         ELzmaFinishMode finishMode,
                         ELzmaStatus *status) {
  SizeT outSize = *destLen;
  SizeT inSize = *srcLen;
  *srcLen = *destLen = 0;
  for (;;) {
    SizeT inSizeCur = inSize, outSizeCur, dicPos;
    ELzmaFinishMode curFinishMode;
    SRes res;
    if (p->dicPos == p->dicBufSize)
      p->dicPos = 0;
    dicPos = p->dicPos;
    if (outSize > p->dicBufSize - dicPos) {
      outSizeCur = p->dicBufSize;
      curFinishMode = LZMA_FINISH_ANY;
    } else {
      outSizeCur = dicPos + outSize;
      curFinishMode = finishMode;
    }

    res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
    src += inSizeCur;
    inSize -= inSizeCur;
    *srcLen += inSizeCur;
    outSizeCur = p->dicPos - dicPos;
    memcpy(dest, p->dic + dicPos, outSizeCur);
    dest += outSizeCur;
    outSize -= outSizeCur;
    *destLen += outSizeCur;
    if (res != 0)
      return res;
    if (outSizeCur == 0 || outSize == 0)
      return SZ_OK;
  }
}

void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc) {
  alloc->Free(alloc, p->probs);
  p->probs = nullptr;
}

static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc) {
  alloc->Free(alloc, p->dic);
  p->dic = nullptr;
}

void LzmaDec_Free(CLzmaDec *p, ISzAlloc *alloc) {
  LzmaDec_FreeProbs(p, alloc);
  LzmaDec_FreeDict(p, alloc);
}

SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size) {
  UInt32 dicSize;
  Byte d;

  if (size < LZMA_PROPS_SIZE)
    return SZ_ERROR_UNSUPPORTED;
  else
    dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);

  if (dicSize < LZMA_DIC_MIN)
    dicSize = LZMA_DIC_MIN;
  p->dicSize = dicSize;

  d = data[0];
  if (d >= (9 * 5 * 5))
    return SZ_ERROR_UNSUPPORTED;

  p->lc = d % 9;
  d /= 9;
  p->pb = d / 5;
  p->lp = d % 5;

  return SZ_OK;
}

static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAlloc *alloc) {
  UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
  if (p->probs == nullptr || numProbs != p->numProbs) {
    LzmaDec_FreeProbs(p, alloc);
    p->probs = (CLzmaProb *)alloc->Alloc(alloc, numProbs * sizeof(CLzmaProb));
    p->numProbs = numProbs;
    if (p->probs == nullptr)
      return SZ_ERROR_MEM;
  }
  return SZ_OK;
}

SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc) {
  CLzmaProps propNew;
  RINOK(LzmaProps_Decode(&propNew, props, propsSize));
  RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
  p->prop = propNew;
  return SZ_OK;
}

SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc) {
  CLzmaProps propNew;
  SizeT dicBufSize;
  RINOK(LzmaProps_Decode(&propNew, props, propsSize));
  RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
  dicBufSize = propNew.dicSize;
  if (p->dic == nullptr || dicBufSize != p->dicBufSize) {
    LzmaDec_FreeDict(p, alloc);
    p->dic = (Byte *)alloc->Alloc(alloc, dicBufSize);
    if (p->dic == nullptr) {
      LzmaDec_FreeProbs(p, alloc);
      return SZ_ERROR_MEM;
    }
  }
  p->dicBufSize = dicBufSize;
  p->prop = propNew;
  return SZ_OK;
}

SRes LzmaDecode(Byte *dest,
                SizeT *destLen,
                const Byte *src,
                SizeT *srcLen,
                const Byte *propData,
                unsigned propSize,
                ELzmaFinishMode finishMode,
                ELzmaStatus *status,
                ISzAlloc *alloc) {
  CLzmaDec p;
  SRes res;
  SizeT inSize = *srcLen;
  SizeT outSize = *destLen;
  *srcLen = *destLen = 0;
  if (inSize < RC_INIT_SIZE)
    return SZ_ERROR_INPUT_EOF;

  LzmaDec_Construct(&p);
  res = LzmaDec_AllocateProbs(&p, propData, propSize, alloc);
  if (res != 0)
    return res;
  p.dic = dest;
  p.dicBufSize = outSize;

  LzmaDec_Init(&p);

  *srcLen = inSize;
  res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);

  if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
    res = SZ_ERROR_INPUT_EOF;

  (*destLen) = p.dicPos;
  LzmaDec_FreeProbs(&p, alloc);
  return res;
}