sergey-brutsky/mutalk

C# UDP multicast message library

mutalk

C# UDP multicast message library inspired by this repo.

main idea

In the world of IoT we often face with the problem how to organize communication between peers.
We often need a protocol that:

1. Can work without dedicated broker.
2. Reliable but rare messages losses are acceptable
3. Based on a pub/sub design.
4. Requires minimum getting started efforts

It looks like udp multicast messaging is an ideal candidate for such kind of protocol.

the essence of the library

1. This is c# micro-library that implements pub/sub udp multicast messaging mechanism
2. Each message is a valid json based string
3. Each message consists of "topic" and "body" parts. Example
   {"t":"test123", "m":"SGVsbG8gd29ybGQgIQ=="}
4. Body of message is base64 encoded string (so you may send an arbitrary bytes)
5. Sender/publisher need to know only about topic to send messages.
6. Receiver/subscriber need to know only about topic for consuming messages.
7. Library hashes "topics" and maps them to ip multicast range "224.0.0.1-224.255.255.254"

from sender/publisher perspective

using var mutalk = new Mutalk("test123"); // "test123" is topic name where messages will be sent
mutalk.SendMessage(Encoding.UTF8.GetBytes("Hello")); // send first message to topic
Task.Delay(1000).Wait();
mutalk.SendMessage(Encoding.UTF8.GetBytes("World !")); // send second message to topic

from receiver/subscriber perspective

using var mutalk = new Mutalk("test123");

mutalk.OnMessage += (_, eventArgs) =>
{
  if (eventArgs.Topic == "test123") // double check topic name due to possible hash collisions
  {
	Console.WriteLine(Encoding.UTF8.GetString(eventArgs.Message));
  }
};

mutalk.ReceiveMessages(cancellationToken); // this is a blocking call until cancellationToken.Cancel()