/// <summary>
/// This callback is for handling the receive of the size header.
/// </summary>
/// <param name="ar"></param>
private void ReceiveSizeCallback(IAsyncResult ar)
{
try {
//Attempt to end the read
var read = socket.EndReceive(ar);
/*An exception should be thrown on EndReceive if the connection was lost.
* However, that is not always the case, so we check if read is zero or less.
* Which means disconnection.
* If there is a disconnection, we throw an exception*/
if (read <= 0)
{
throw new SocketException((int)SocketError.ConnectionAborted);
}
//increment the total data read
dataRead += read;
//If we didn't receive the full buffer size, something is lagging behind.
if (dataRead < SIZE_HEADER)
{
//Begin receive again
BeginReceive();
//If we did receive the full header, then begin reading the payload
}
else
{
dataRead = 0;
//Get the converted int value for the payload size from the received data
dataExpected = BitConverter.ToInt32(buffer, 0);
if (dataExpected == NetConstants.PING_REQUEST)
{
SendPingResponse();
BeginReceive();
return;
}
else if (dataExpected == NetConstants.PING_RESPONSE)
{
double ping = ((double)pingWatch.ElapsedTicks / Stopwatch.Frequency) * 1000.0;
Ping = ping;
BeginReceive();
PingUpdated?.Invoke(this, ping);
pingWatch.Restart();
return;
}
if (dataExpected > ClientOptions.MaxPacketSize)
{
throw new ProtocolViolationException($"Illegal payload size: payload size exeeded whats max allowed {dataExpected} > {ClientOptions.MaxPacketSize}");
}
else if (dataExpected < ClientOptions.MinPacketSize)
{
throw new ProtocolViolationException($"Illegal payload size: payload size is less than allowed {dataExpected} < {ClientOptions.MinPacketSize}");
}
else if (dataExpected == 0)
{
throw new ProtocolViolationException("Illegal payload size: payload had no length");
}
else
{
/*If the expected data size is bigger than what
* we can hold we need to write it to a resizable stream */
if (dataExpected > buffer.Length)
{
//Initialize a new MemStream to receive chunks of the payload
payloadStream = new MemoryStream(ClientOptions.BufferSize);
//Start the receive loop of the payload
socket.BeginReceive(buffer, 0, buffer.Length, 0,
ReceivePayloadStreamCallback, null);
}
else
{
//Else we receive directly into the buffer
socket.BeginReceive(buffer, 0, dataExpected, 0,
ReceivePayloadBufferedCallback, null);
}
}
}
} catch (NullReferenceException) {
return;
} catch (ObjectDisposedException) {
return;
} catch (Exception ex) {
HandleDisconnect(ex);
}
}
private void ProtocolClient_PingUpdated(ProtocolClient sender, double ping)
{
PingUpdated?.Invoke(sender, ping);
}
