private void AsyncReceive(object state)
{
while (true)
{
byte[] readBuffer;
lock (_readBuffers)
{
if (_readBuffers.Count == 0)
{
lock (_readingMessagesLock)
{
_readingMessages = false;
}
return;
}
readBuffer = _readBuffers.Dequeue();
}
_readableDataLen += readBuffer.Length;
bool process = true;
while (process)
{
switch (_receiveState)
{
case ReceiveType.Header:
{
if (_payloadBuffer == null)
{
_payloadBuffer = new byte[HEADER_SIZE];
}
if (_readableDataLen + _writeOffset >= HEADER_SIZE)
{
// completely received header
int headerLength = HEADER_SIZE - _writeOffset;
try
{
Array.Copy(readBuffer, _readOffset, _payloadBuffer, _writeOffset, headerLength);
_payloadLen = BitConverter.ToInt32(_payloadBuffer, _readOffset);
if (_payloadLen <= 0 || _payloadLen > MAX_MESSAGE_SIZE)
{
throw new Exception("invalid header");
}
// try to re-use old payload buffers which fit
if (_payloadBuffer.Length <= _payloadLen + HEADER_SIZE)
{
Array.Resize(ref _payloadBuffer, _payloadLen + HEADER_SIZE);
}
}
catch (Exception)
{
process = false;
Disconnect();
break;
}
_readableDataLen -= headerLength;
_writeOffset += headerLength;
_readOffset += headerLength;
_receiveState = ReceiveType.Payload;
}
else // _readableDataLen + _writeOffset < HeaderSize
{
// received only a part of the header
try
{
Array.Copy(readBuffer, _readOffset, _payloadBuffer, _writeOffset, _readableDataLen);
}
catch (Exception)
{
process = false;
Disconnect();
break;
}
_readOffset += _readableDataLen;
_writeOffset += _readableDataLen;
process = false;
// nothing left to process
}
break;
}
case ReceiveType.Payload:
{
int length = (_writeOffset - HEADER_SIZE + _readableDataLen) >= _payloadLen
? _payloadLen - (_writeOffset - HEADER_SIZE)
: _readableDataLen;
try
{
Array.Copy(readBuffer, _readOffset, _payloadBuffer, _writeOffset, length);
}
catch (Exception)
{
process = false;
Disconnect();
break;
}
_writeOffset += length;
_readOffset += length;
_readableDataLen -= length;
if (_writeOffset - HEADER_SIZE == _payloadLen)
{
// completely received payload
try
{
using (PayloadReader pr = new PayloadReader(_payloadBuffer, _payloadLen + HEADER_SIZE, false))
{
IMessage message = pr.ReadMessage();
OnClientRead(message, _payloadBuffer.Length);
}
}
catch (Exception)
{
process = false;
Disconnect();
break;
}
_receiveState = ReceiveType.Header;
_payloadLen = 0;
_writeOffset = 0;
}
if (_readableDataLen == 0)
{
process = false;
}
break;
}
}
}
_readOffset = 0;
_readableDataLen = 0;
}
}
