/// <summary>
/// Return a message or null if timout passes without a complete message ending with Eof can be found
/// </summary>
/// <param name="cancelationToken"></param>
/// <returns></returns>
public async Task <IncomingMessage> ReadAsync(CancellationToken cancelationToken)
{
// at start, some left overs might still be at the begining of the buffer,
// currentIndex can therefore be greater than 0
byte[] eof = { 0x0D, 0x0A };
var eofMatchCharCount = 0;
while (eofMatchCharCount < eof.Length)
{
var byteCount = await _byteStream.ReadAsync(_buffer, _currentBufferIndex, BufferSize - _currentBufferIndex, cancelationToken);
if (byteCount <= 0)
{
return(null);
}
_currentBufferIndex += byteCount;
while (eofMatchCharCount < eof.Length && byteCount > 0)
{
if (_buffer[_currentBufferIndex - byteCount] == eof[eofMatchCharCount])
{
eofMatchCharCount++;
}
else
{
eofMatchCharCount = 0;
}
byteCount--;
}
if (eofMatchCharCount != eof.Length)
{
continue;
}
var msgBytes = new byte[_currentBufferIndex - byteCount];
for (var i = 0; i < _currentBufferIndex - byteCount; i++)
{
msgBytes[i] = _buffer[i];
}
var parser = _parserFactory.Create(msgBytes);
var msg = parser.Parse(msgBytes);
for (var i = 0; i < byteCount; i++)
{
_buffer[i] = _buffer[_currentBufferIndex - byteCount + i];
}
_currentBufferIndex = byteCount;
return(msg);
}
return(null);
}
