/// <summary>
/// This method is called by I/O Completed() when an asynchronous send completes.
/// If all of the data has been sent, then this method calls StartReceive
/// to start another receive op on the socket to read any additional
/// data sent from the client. If all of the data has NOT been sent, then it
/// calls StartSend to send more data.
/// </summary>
/// <param name="e"></param>
private void ProcessSend(SocketAsyncEventArgs receiveSendEventArgs)
{
DataHoldingUserToken receiveSendToken =
(DataHoldingUserToken)receiveSendEventArgs.UserToken;
receiveSendToken.sendBytesRemainingCount =
receiveSendToken.sendBytesRemainingCount
- receiveSendEventArgs.BytesTransferred;
receiveSendToken.bytesSentAlreadyCount +=
receiveSendEventArgs.BytesTransferred;
if (receiveSendEventArgs.SocketError == SocketError.Success)
{
if (receiveSendToken.sendBytesRemainingCount == 0)
{
StartReceive(receiveSendEventArgs);
}
else
{
//If some of the bytes in the message have NOT been sent,
//then we will need to post another send operation.
//So let's loop back to StartSend().
StartSend(receiveSendEventArgs);
}
}
else
{
//If we are in this else-statement, there was a socket error.
//In this example we'll just close the socket if there was a socket error
//when receiving data from the client.
receiveSendToken.Reset();
CloseClientSocket(receiveSendEventArgs);
}
}
/// <summary>
/// This method is invoked by the IO_Completed method
/// when an asynchronous receive operation completes.
/// If the remote host closed the connection, then the socket is closed.
/// Otherwise, we process the received data. And if a complete message was
/// received, then we do some additional processing, to
/// respond to the client.
/// </summary>
/// <param name="receiveSendEventArgs"></param>
private void ProcessReceive(SocketAsyncEventArgs receiveSendEventArgs)
{
DataHoldingUserToken receiveSendToken =
(DataHoldingUserToken)receiveSendEventArgs.UserToken;
// If there was a socket error, close the connection. This is NOT a normal
// situation, if you get an error here.
// In the Microsoft example code they had this error situation handled
// at the end of ProcessReceive. Putting it here improves readability
// by reducing nesting some.
if (receiveSendEventArgs.SocketError != SocketError.Success)
{
receiveSendToken.Reset();
CloseClientSocket(receiveSendEventArgs);
// Jump out of the ProcessReceive method.
return;
}
// If no data was received, close the connection. This is a NORMAL
// situation that shows when the client has finished sending data.
if (receiveSendEventArgs.BytesTransferred == 0)
{
receiveSendToken.Reset();
CloseClientSocket(receiveSendEventArgs);
return;
}
// The BytesTransferred property tells us how many bytes
// we need to process.
Int32 remainingBytesToProcess = receiveSendEventArgs.BytesTransferred;
// If we have not got all of the prefix already,
// then we need to work on it here.
if (receiveSendToken.receivedPrefixBytesDoneCount < this.socketListenerSettings.ReceivePrefixLength)
{
remainingBytesToProcess = prefixHandler.HandlePrefix(receiveSendEventArgs,
receiveSendToken, remainingBytesToProcess);
if (remainingBytesToProcess == 0)
{
// We need to do another receive op, since we do not have
// the message yet, but remainingBytesToProcess == 0.
StartReceive(receiveSendEventArgs);
// Jump out of the method.
return;
}
}
// If we have processed the prefix, we can work on the message now.
// We'll arrive here when we have received enough bytes to read
// the first byte after the prefix.
bool incomingTcpMessageIsReady = messageHandler.HandleMessage(receiveSendEventArgs,
receiveSendToken, remainingBytesToProcess);
if (incomingTcpMessageIsReady == true)
{
// Pass the DataHolder object to the Mediator here. The data in
// this DataHolder can be used for all kinds of things that an
// intelligent and creative person like you might think of.
receiveSendToken.theMediator.HandleData(receiveSendToken.theDataHolder);
// Create a new DataHolder for next message.
receiveSendToken.CreateNewDataHolder();
//Reset the variables in the UserToken, to be ready for the
//next message that will be received on the socket in this
//SAEA object.
receiveSendToken.Reset();
receiveSendToken.theMediator.PrepareOutgoingData();
StartSend(receiveSendToken.theMediator.GiveBack());
}
else
{
// Since we have NOT gotten enough bytes for the whole message,
// we need to do another receive op. Reset some variables first.
// All of the data that we receive in the next receive op will be
// message. None of it will be prefix. So, we need to move the
// receiveSendToken.receiveMessageOffset to the beginning of the
// receive buffer space for this SAEA.
receiveSendToken.receiveMessageOffset = receiveSendToken.bufferOffsetReceive;
// Do NOT reset receiveSendToken.receivedPrefixBytesDoneCount here.
// Just reset recPrefixBytesDoneThisOp.
receiveSendToken.recPrefixBytesDoneThisOp = 0;
// Since we have not gotten enough bytes for the whole message,
// we need to do another receive op.
StartReceive(receiveSendEventArgs);
}
}