private static int DecodeDistance(BitStreamReader bitStream, int length, int dictSizeBits)
{
Contract.Requires(bitStream != null);
Contract.Requires(length >= 0);
Contract.Requires(dictSizeBits >= 0);
Contract.Requires(dictSizeBits < BitStreamReader.MaxBitCount);
if (bitStream.EnsureBits(8) == false)
{
return(0);
}
var pos = (int)_sPosition1[bitStream.PeekByte()];
var skip = _sDistBits[pos]; // Number of bits to skip.
// Skip the appropriate number of bits
Contract.Assume(skip < BitStreamReader.MaxBitCount);
if (bitStream.ReadBits(skip) == -1)
{
return(0);
}
if (length == 2)
{
if (bitStream.EnsureBits(2) == false)
{
return(0);
}
pos = (pos << 2) | bitStream.ReadBits(2);
}
else
{
if (bitStream.EnsureBits(dictSizeBits) == false)
{
return(0);
}
pos = ((pos << dictSizeBits)) | bitStream.ReadBits(dictSizeBits);
}
return(pos + 1);
}
private static int DecodeDistance(BitStreamReader bitStream, int length, int dictSizeBits)
{
Contract.Requires(bitStream != null);
Contract.Requires(length >= 0);
Contract.Requires(dictSizeBits >= 0);
Contract.Requires(dictSizeBits < BitStreamReader.MaxBitCount);
if (bitStream.EnsureBits(8) == false)
return 0;
var pos = (int)_sPosition1[bitStream.PeekByte()];
var skip = _sDistBits[pos]; // Number of bits to skip.
// Skip the appropriate number of bits
Contract.Assume(skip < BitStreamReader.MaxBitCount);
if (bitStream.ReadBits(skip) == -1)
return 0;
if (length == 2)
{
if (bitStream.EnsureBits(2) == false)
return 0;
pos = (pos << 2) | bitStream.ReadBits(2);
}
else
{
if (bitStream.EnsureBits(dictSizeBits) == false)
return 0;
pos = ((pos << dictSizeBits)) | bitStream.ReadBits(dictSizeBits);
}
return pos + 1;
}