private void DoInit()
{
if (initdone)
{
return;
}
initdone = true;
// http://stackoverflow.com/a/2331025/277304
const int cmf = 0x78;
var flg = 218; // sorry about the following lines
if (CompressLevel >= 5 && CompressLevel <= 6)
{
flg = 156;
}
else if (CompressLevel >= 3 && CompressLevel <= 4)
{
flg = 94;
}
else if (CompressLevel <= 2)
{
flg = 1;
}
flg -= (((cmf * 256) + flg) % 31); // just in case
if (flg < 0)
{
flg += 31;
}
RawStream.WriteByte(cmf);
RawStream.WriteByte((byte)flg);
}
public override void WriteByte(byte value)
{
if (m_IsCompressed)
{
m_Buffer.WriteByte(value);
if (m_Buffer.Position >= m_BlockSize)
{
FlushBuffer();
}
}
else
{
RawStream.WriteByte(value);
}
}
public override void Close()
{
if (!initdone)
{
DoInit(); // can happen if never called write
}
if (closed)
{
return;
}
closed = true;
// sigh ... no only must I close the parent stream to force a flush, but I must save a reference
// raw stream because (apparently) Close() sets it to null (shame on you, MS developers)
if (deflateStream is object)
{
deflateStream.Close();
}
else
{ // second hack: empty input?
RawStream.WriteByte(3);
RawStream.WriteByte(0);
}
// add crc
var crcv = adler32.GetValue();
RawStream.WriteByte((byte)((crcv >> 24) & 0xFF));
RawStream.WriteByte((byte)((crcv >> 16) & 0xFF));
RawStream.WriteByte((byte)((crcv >> 8) & 0xFF));
RawStream.WriteByte((byte)(crcv & 0xFF));
if (!LeaveOpen)
{
RawStream.Close();
}
}