/// <summary>
/// Callback routine for handling send completes.
/// </summary>
/// <param name="result">The result of the asynchronous operation.</param>
static private void EventSendComplete(IAsyncResult result)
{
// Get the subscriber object as context for this request.
IProcEventSubscriber sub = null;
try
{
sub = ( IProcEventSubscriber )result.AsyncState;
sub.eventSocket.EndSend(result);
}
catch (Exception e)
{
log.Error(e, String.Format("{0} : Error in send complete.", sub.port));
}
}
/// <summary>
/// Event registration service.
/// </summary>
private void RegistrationService()
{
bool exitLoop = false;
while (!exitLoop)
{
try
{
// Wait for an incoming request.
Socket clientSocket = regSocket.Accept();
try
{
// Make sure that this request came from the loopback address. Off-box requests are not supported.
if (IPAddress.IsLoopback((clientSocket.RemoteEndPoint as IPEndPoint).Address))
{
// Setup an asynchronous receive so all requests get processed in a different execution thread.
IProcEventSubscriber sub = new IProcEventSubscriber(clientSocket);
clientSocket.BeginReceive(sub.ReceiveBuffer, 0, sub.ReceiveBuffer.Length, SocketFlags.None, new AsyncCallback(IProcEventSubscriber.MessageHandler), sub);
}
else
{
clientSocket.Close();
}
}
catch (SocketException e)
{
log.Error(e, "Socket exception");
}
catch (Exception e)
{
log.Error(e, "Cannot begin message processing due to unknown exception.");
clientSocket.Close();
}
}
catch (SocketException e)
{
exitLoop = true;
log.Debug(e, "Error socket exception. Exiting loop.");
}
catch (Exception e)
{
// Stay in the loop until the socket is closed.
log.Debug(e, "Error exception.");
}
}
}
/// <summary>
/// Processes incoming messages intended for this subscriber.
/// </summary>
/// <param name="result">The result of the asynchronous operation.</param>
static internal void MessageHandler(IAsyncResult result)
{
// Get the subscriber object as context for this request.
IProcEventSubscriber sub = ( IProcEventSubscriber )result.AsyncState;
try
{
// End the pending read operation.
int bytesReceived = sub.eventSocket.EndReceive(result);
if (bytesReceived > 0)
{
try
{
// Keep track of how much data is in the buffer.
sub.bufferLength += bytesReceived;
int bytesToProcess = sub.bufferLength;
int msgIndex = 0;
// Process as much as is available.
while (bytesToProcess > 0)
{
// There needs to be atleast 4 bytes for the message length.
if (bytesToProcess >= 4)
{
// Get the length of the message, add in the prepended length.
int msgLength = BitConverter.ToInt32(sub.receiveBuffer, msgIndex) + 4;
// See if the entire message is represented in the buffer.
if (bytesToProcess >= msgLength)
{
// Process the message received from the client. Skip the message length.
sub.ProcessMessage(new ASCIIEncoding().GetString(sub.receiveBuffer, msgIndex + 4, msgLength - 4));
msgIndex += msgLength;
bytesToProcess -= msgLength;
}
else
{
break;
}
}
else
{
break;
}
}
// Update how much data is left in the buffer.
sub.bufferLength = bytesToProcess;
// If any data has been processed at the beginning of the buffer, the unprocessed
// data needs to be moved to the front.
if ((bytesToProcess > 0) && (msgIndex > 0))
{
// Move any existing data up.
Buffer.BlockCopy(sub.receiveBuffer, msgIndex, sub.receiveBuffer, 0, bytesToProcess);
}
}
catch (Exception e)
{
log.Error(e, "{0} : Error processing event message from client.", sub.port);
}
// Repost the buffer.
sub.eventSocket.BeginReceive(sub.receiveBuffer, sub.bufferLength, sub.receiveBuffer.Length - sub.bufferLength, SocketFlags.None, new AsyncCallback(MessageHandler), sub);
}
else
{
// The client is going away. Clean up his events.
log.Debug("Client {0} has terminated the connection.", (sub.eventSocket.RemoteEndPoint as IPEndPoint).Address);
sub.DisposeSubscribers();
sub.eventSocket.Shutdown(SocketShutdown.Both);
sub.eventSocket.Close();
IProcEventSubscriber.subscriberTable.Remove(sub.port);
}
}
catch (SocketException e)
{
log.Error(e, "{0} : Error communication failure.", sub.port);
IProcEventSubscriber.subscriberTable.Remove(sub.port);
}
catch (Exception e)
{
log.Error(e, "{0} : Error exception occurred.", sub.port);
IProcEventSubscriber.subscriberTable.Remove(sub.port);
}
}
