public unsafe byte[] Decompress(byte[] sourceBytes, int sourceIndex, int beforeGap, int afterGap)
{
if (sourceBytes == null)
{
AcedMCException.ThrowArgumentNullException("sourceBytes");
}
else
{
int byteCount;
fixed(byte *pSrcBytes = &sourceBytes[sourceIndex])
byteCount = *((int *)pSrcBytes);
if (byteCount < 0)
{
byteCount = -byteCount;
}
var result = new byte[byteCount + beforeGap + afterGap];
if (byteCount != 0)
{
Decompress(sourceBytes, sourceIndex, result, beforeGap);
}
return(result);
}
return(null);
}
private unsafe int GetBit()
{
uint hold = (uint)_hold;
int bits = _bits;
if (bits != 0)
{
bits--;
}
else if (_srcIndex < _break32Offset)
{
_srcIndex += 4;
hold = *((uint *)_pSrcBytes);
_pSrcBytes += 4;
bits = 31;
}
else if (_srcIndex < _breakOffset)
{
_srcIndex++;
hold = (uint)(*_pSrcBytes);
_pSrcBytes++;
bits = 7;
}
else
{
AcedMCException.ThrowReadBeyondTheEndException();
}
_hold = (int)(hold >> 1);
_bits = bits;
return((int)(hold & 1));
}
private unsafe int GetNBits(int n)
{
int hold = _hold;
int bits = _bits;
while (bits < n)
{
if (bits < 8 && _srcIndex < _break32Offset)
{
_srcIndex += 3;
hold |= (_pSrcBytes[0] | (_pSrcBytes[1] << 8) | (_pSrcBytes[2] << 16)) << bits;
_pSrcBytes += 3;
bits += 24;
}
else if (_srcIndex < _breakOffset)
{
_srcIndex++;
hold |= (*_pSrcBytes) << bits;
_pSrcBytes++;
bits += 8;
}
else
{
AcedMCException.ThrowReadBeyondTheEndException();
}
}
_hold = hold >> n;
_bits = bits - n;
return(hold & ((1 << n) - 1));
}
private unsafe int GetCode(int *tree)
{
int code = 1;
int hold = _hold;
do
{
while (_bits != 0)
{
code = tree[code + (hold & 1)];
hold >>= 1;
_bits--;
if (code <= 0)
{
goto CodeFound;
}
}
if (_srcIndex < _break32Offset)
{
_srcIndex += 4;
hold = *((int *)_pSrcBytes);
_pSrcBytes += 4;
code = tree[code + (hold & 1)];
hold = (int)((uint)hold >> 1);
_bits = 31;
}
else if (_srcIndex < _breakOffset)
{
_srcIndex++;
hold = (int)(*_pSrcBytes);
_pSrcBytes++;
code = tree[code + (hold & 1)];
hold >>= 1;
_bits = 7;
}
else
{
AcedMCException.ThrowReadBeyondTheEndException();
}
} while (code > 0);
CodeFound:
_hold = hold;
return(-code);
}
public static unsafe int GetDecompressedLength(byte[] sourceBytes, int sourceIndex)
{
if (sourceBytes == null)
{
AcedMCException.ThrowArgumentNullException("sourceBytes");
}
else
fixed(byte *pSrcBytes = &sourceBytes[sourceIndex])
{
var result = *((int *)pSrcBytes);
if (result >= 0)
{
return(result);
}
return(-result);
}
return(0);
}
private unsafe void ReadNonCompressedBlock()
{
_inCounter += GetNBits(8);
var bits = _bits;
while (_inCounter > 0 && _outCounter > 0)
{
var hold = _hold;
if (bits < 8)
{
if (_srcIndex < _break32Offset)
{
_srcIndex += 3;
hold |= (_pSrcBytes[0] | (_pSrcBytes[1] << 8) | (_pSrcBytes[2] << 16)) << bits;
_pSrcBytes += 3;
bits += 24;
}
else if (_srcIndex < _breakOffset)
{
_srcIndex++;
hold |= (*_pSrcBytes) << bits;
_pSrcBytes++;
bits += 8;
}
else
{
AcedMCException.ThrowReadBeyondTheEndException();
}
}
_hold = hold >> 8;
bits -= 8;
*_pDstBytes = (byte)hold;
_inCounter--;
_outCounter--;
_pDstBytes++;
}
_bits = bits;
}
public unsafe int Decompress(byte[] sourceBytes, int sourceIndex, byte[] destinationBytes, int destinationIndex)
{
if (sourceBytes == null)
{
AcedMCException.ThrowArgumentNullException("sourceBytes");
}
else
{
if (destinationBytes == null)
return(GetDecompressedLength(sourceBytes, sourceIndex));
fixed(byte *pSrcBytes = &sourceBytes[sourceIndex], pDstBytes = &destinationBytes[destinationIndex])
{
_pSrcBytes = pSrcBytes;
_pDstBytes = pDstBytes;
var byteCount = *((int *)_pSrcBytes);
if (byteCount <= 0)
{
byteCount = -byteCount;
if (destinationBytes.Length - destinationIndex < byteCount)
{
AcedMCException.ThrowNoPlaceToStoreDecompressedDataException();
}
if (byteCount > 0)
{
Buffer.BlockCopy(sourceBytes, sourceIndex + 4, destinationBytes, destinationIndex,
byteCount);
}
return(byteCount);
}
if (destinationBytes.Length - destinationIndex < byteCount)
AcedMCException.ThrowNoPlaceToStoreDecompressedDataException();
fixed(int *pCharTree = &_charTree[0], pDistTree = &_distTree[0],
pChLenTree = &_chLenTree[0], pBitLen = &_bitLen[0],
pBitCount = &_bitCount[0], pNextCode = &_nextCode[0],
pCharExBitLength = &AcedConsts.CharExBitLength[0],
pCharExBitBase = &AcedConsts.CharExBitBase[0],
pDistExBitLength = &AcedConsts.DistExBitLength[0],
pDistExBitBase = &AcedConsts.DistExBitBase[0])
{
_pCharTree = pCharTree;
_pDistTree = pDistTree;
_pChLenTree = pChLenTree;
_pBitLen = pBitLen;
_pBitCount = pBitCount;
_pNextCode = pNextCode;
_pCharExBitLength = pCharExBitLength;
_pCharExBitBase = pCharExBitBase;
_pDistExBitLength = pDistExBitLength;
_pDistExBitBase = pDistExBitBase;
_bits = 0;
_hold = 0;
_srcIndex = sourceIndex + 4;
_pSrcBytes += 4;
_breakOffset = sourceBytes.Length;
_break32Offset = _breakOffset - 3;
int length1, distance1;
_outCounter = byteCount;
while (_outCounter > 0)
{
ReadBlockHeader();
while (_inCounter > 0 && _outCounter > 0)
{
var c = GetCode(_pCharTree);
_inCounter--;
if (c < AcedConsts.FirstLengthChar)
{
*_pDstBytes = (byte)c;
_outCounter--;
_pDstBytes++;
}
else
{
c -= AcedConsts.FirstCharWithExBit;
if (c < 0)
{
length1 = c + 19;
}
else
{
length1 = GetNBits(_pCharExBitLength[c]) + _pCharExBitBase[c];
}
c = GetCode(_pDistTree);
if (c < 3)
{
switch (c)
{
case 0:
distance1 = _r0;
break;
case 1:
distance1 = _r1;
_r1 = _r0;
_r0 = distance1;
break;
default:
distance1 = _r2;
_r2 = _r0;
_r0 = distance1;
break;
}
}
else
{
distance1 = _pDistExBitBase[c];
if (c >= AcedConsts.FirstDistWithExBit)
{
distance1 += GetNBits(_pDistExBitLength[c]);
_r2 = _r1;
_r1 = _r0;
_r0 = distance1;
}
}
AcedUtils.CopyBytes(_pDstBytes - distance1, _pDstBytes, length1);
_outCounter -= length1;
_pDstBytes += length1;
}
}
}
}
return(byteCount);
}
}
return(0);
}