public void WriteBits(int data, int numBits)
{
//copy lower x bit to buffer and flip buffer
for (var needToWrite = numBits; needToWrite != 0;)
{
var capacity = encoding.BitsPerChar - bitsInBuffer;
if (capacity == 0)
{
WriteBuffer();
capacity = encoding.BitsPerChar;
}
if (needToWrite <= capacity)
{
buffer |= (data << bitsInBuffer);
bitsInBuffer += needToWrite;
needToWrite = 0;
}
else
{
var mask = BitReversalTable.GetBitMask(capacity);
var portion = (data & mask);
var shifted = (portion << bitsInBuffer);
buffer |= shifted;
data >>= capacity;
bitsInBuffer += capacity;
needToWrite -= capacity;
}
}
}
public DataEncoding(
int bitsPerChar,
string codepage,
IReadOnlyDictionary <char, int> reverseCodePage,
BitReversalTable bitReversalTable)
{
BitsPerChar = bitsPerChar;
CodePage = codepage;
ReverseCodePage = reverseCodePage;
BitReversalTable = bitReversalTable;
}
public static BitReversalTable GetTable(int bitWidth)
{
if (tableCache.TryGetValue(bitWidth, out var ret))
{
return(ret);
}
else
{
ret = new BitReversalTable(bitWidth);
tableCache[bitWidth] = ret;
return(ret);
}
}
