lzmadec.c

LZMA压缩解压算法

          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(p->probs);
  p->probs = 0;
}

static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc)
{
  alloc->Free(p->dic);
  p->dic = 0;
}

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 == 0 || numProbs != p->numProbs)
  {
    LzmaDec_FreeProbs(p, alloc);
    p->probs = (CLzmaProb *)alloc->Alloc(numProbs * sizeof(CLzmaProb));
    p->numProbs = numProbs;
    if (p->probs == 0)
      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 == 0 || dicBufSize != p->dicBufSize)
  {
    LzmaDec_FreeDict(p, alloc);
    p->dic = (Byte *)alloc->Alloc(dicBufSize);
    if (p->dic == 0)
    {
      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;
}

int DecodeSize(LzDecodeSize *p)
{
	unsigned char header1[HEADERSIZE];
	unsigned char *src = NULL;
	unsigned int srclen = 0;
	unsigned int destlen = 0;
	unsigned int unpackSize = 0, i=0;
	unsigned int propsize = LZMA_PROPS_SIZE;
	CLzmaProps propNew;
	src  = p->src;
	srclen = p->srclen;
	destlen = *(p->destlen);
	
	if ((srclen<13 )|| src == NULL)
	{
		return -1;
	}
	p->memcpy(header1,src,13);
	for (i = 0; i < 8; i++)
		unpackSize += (unsigned long)header1[LZMA_PROPS_SIZE + i] << (i * 8);
	*(p->destlen) = unpackSize;
	
	RINOK(LzmaProps_Decode(&propNew, header1, propsize));
	*(p->dictsize)=propNew.dicSize;			
	return	1; 
};

int Decode(LzDecode *p)
{
	unsigned char header1[HEADERSIZE];
	unsigned int  header1Size = LZMA_PROPS_SIZE;
	CLzmaDec pi;
	ELzmaStatus ppz = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
	ISzAlloc alloc;
	unsigned int  i = 0,res = 0;
	unsigned int unpackSize = 0;
	unsigned int headerllen = HEADERSIZE;
	unsigned char *src = NULL;
	unsigned char *dest = NULL;
	unsigned char *Tdest = NULL;
	unsigned int srclen = 0;
	unsigned int destlen = 0;
	
	src  = p->src;
	dest = p->dest;
	srclen = p->srclen;
	destlen = *(p->destlen);
	alloc.Alloc = p->Alloc;
	alloc.Free = p->Free;
	
	p->memcpy(header1,src,13);
	for (i = 0; i < 8; i++)
		unpackSize += (unsigned long)header1[LZMA_PROPS_SIZE + i] << (i * 8);
	if (unpackSize > destlen)
	{
		*(p->destlen) = unpackSize;
		return -1;
	}
	
	LzmaDec_Construct(&pi);
	RINOK(LzmaDec_Allocate(&pi,header1,header1Size,&alloc));
	LzmaDec_Init(&pi);
	Tdest = src + HEADERSIZE;
	LzmaDec_DecodeToBuf(&pi, dest, &unpackSize, Tdest,&srclen, LZMA_FINISH_ANY, &ppz);
	return	unpackSize;	
}