public ZeroMqDeviceService()
{
//We are using NetMQ to retrieve the available devices in the following manner:
// queryRouterSocket -> querySocket -> All Devices In -> All Device out -> commandSocket -> queryRouterSocket
// Router -> Publisher -> Subscriber -> Dealer -> Router -> Router
//This pattern allows any client to request the list of Clients in the commandSocket. So we can send messages directly to clients at another point in time.
queryRouterSocket.ReceiveReady += (o, e) =>
{
//Send a message to all clients with the following fields:
// 1 - Subscription Name
// 2 - queryRouterSocket id
// 3 - command type
var incomingMsg = e.Socket.ReceiveMultipartBytes();
var messageToServer = new NetMQMessage();
messageToServer.Append("All");
incomingMsg.ForEach((val) => { messageToServer.Append(val); });
querySocket.SendMultipartMessage(messageToServer);
};
commandSocket.ReceiveReady += (o, e) =>
{
//Recieve a message from the clients with the following fields:
// 1 - Client Id
// 2 - queryRouterSocket id
// 3 - response
var msg = commandSocket.ReceiveMultipartBytes();
msg.RemoveAt(0); //Remove the Client id
var messageToClient = new NetMQMessage();
msg.ForEach((val) => { messageToClient.Append(val); });
queryRouterSocket.SendMultipartMessage(messageToClient); //forward the message
};
poller = new NetMQPoller {
queryRouterSocket, commandSocket
};
poller.RunAsync();
}
internal void doHeartbeat()
{
try
{
while (true)
{
var hb = hbSocket.ReceiveMultipartBytes();
hbSocket.SendMultipartBytes(hb);
}
}
catch (Exception ex)
{
handleException(ex);
}
}