private unsafe void LoadDistTree()
{
int n, m, p, code;
AcedUtils.Fill(0, _pBitLen, AcedConsts.DistCount);
LoadCharDistLengths(GetNBits(6) + 1);
AcedUtils.Fill(0, _pDistTree, AcedConsts.DistTreeSize);
_pNextCode[1] = 0;
_pNextCode[2] = n = _pBitCount[1] << 1;
_pNextCode[3] = n = (n + _pBitCount[2]) << 1;
_pNextCode[4] = n = (n + _pBitCount[3]) << 1;
_pNextCode[5] = n = (n + _pBitCount[4]) << 1;
_pNextCode[6] = n = (n + _pBitCount[5]) << 1;
_pNextCode[7] = n = (n + _pBitCount[6]) << 1;
_pNextCode[8] = n = (n + _pBitCount[7]) << 1;
_pNextCode[9] = n = (n + _pBitCount[8]) << 1;
_pNextCode[10] = n = (n + _pBitCount[9]) << 1;
_pNextCode[11] = n = (n + _pBitCount[10]) << 1;
_pNextCode[12] = n = (n + _pBitCount[11]) << 1;
_pNextCode[13] = n = (n + _pBitCount[12]) << 1;
_pNextCode[14] = n = (n + _pBitCount[13]) << 1;
var treeLen = 2;
for (var i = 0; i < AcedConsts.DistCount; i++)
{
n = _pBitLen[i];
if (n == 0)
{
continue;
}
m = _pNextCode[n];
code = (int)AcedUtils.ReverseBits((uint)m, n);
_pNextCode[n] = m + 1;
p = 1;
while (true)
{
p += code & 1;
code >>= 1;
n--;
if (n != 0)
{
m = p;
p = _pDistTree[p];
if (p != 0)
{
continue;
}
p = treeLen + 1;
treeLen = p + 1;
_pDistTree[m] = p;
}
else
{
_pDistTree[p] = -i;
break;
}
}
}
}
private unsafe void LoadChLenTree()
{
int n, m, p, i, code;
AcedUtils.Fill(0, _pBitCount, AcedConsts.MaxChLenBits + 1);
for (i = 0; i < AcedConsts.ChLenCount; i++)
{
n = GetNBits(3);
_pBitLen[i] = n;
_pBitCount[n]++;
}
AcedUtils.Fill(0, _pChLenTree, AcedConsts.ChLenTreeSize);
_pNextCode[1] = 0;
_pNextCode[2] = n = _pBitCount[1] << 1;
_pNextCode[3] = n = (n + _pBitCount[2]) << 1;
_pNextCode[4] = n = (n + _pBitCount[3]) << 1;
_pNextCode[5] = n = (n + _pBitCount[4]) << 1;
_pNextCode[6] = n = (n + _pBitCount[5]) << 1;
_pNextCode[7] = n = (n + _pBitCount[6]) << 1;
var treeLen = 2;
for (i = 0; i < AcedConsts.ChLenCount; i++)
{
n = _pBitLen[i];
if (n == 0)
{
continue;
}
m = _pNextCode[n];
code = (int)AcedUtils.ReverseBits((uint)m, n);
_pNextCode[n] = m + 1;
p = 1;
while (true)
{
p += code & 1;
code >>= 1;
n--;
if (n != 0)
{
m = p;
p = _pChLenTree[p];
if (p != 0)
{
continue;
}
p = treeLen + 1;
treeLen = p + 1;
_pChLenTree[m] = p;
}
else
{
_pChLenTree[p] = -i;
break;
}
}
}
}
private unsafe void LoadCharDistLengths(int count)
{
int c, lastLen = 0;
var p = _pBitLen;
AcedUtils.Fill(0, _pBitCount, AcedConsts.MaxBits + 1);
while (count > 0)
{
c = GetCode(_pChLenTree);
if (c < 15)
{
*p = c;
_pBitCount[c]++;
p++;
lastLen = c;
count--;
}
else
{
if (c < 17)
{
if (c == 15)
{
c = 2;
}
else
{
c = GetBit() + 3;
}
}
else if (c == 17)
{
c = GetNBits(2) + 5;
}
else if (c == 18)
{
c = GetNBits(3) + 9;
}
else
{
c = GetNBits(7) + 17;
}
count -= c;
_pBitCount[lastLen] += c;
do
{
c--;
*p = lastLen;
p++;
} while (c != 0);
}
}
}
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);
}
