DataflowPubsub

A class library for an in memory, asynchronous message based publish subscribe pattern to communicate between task based/multithreaded components.

The implementation uses Dataflow (Task Parallel Library) components.

What's new

Version 1.1.0, 9 dec 2021 : removed superfluous BufferBlock in subscriber

How To Use

Add a reference to the nuget package

dotnet add package DataflowPubsub

Create subscribers trough an instance of MessageBus. You subscribe to any BaseMessage derived type (a few basic types like TextMessage and BinaryMessage are defined in the library). Any message can have a 'topic' that can be used in filtering. (Any public message properties can be filtered upon)

var messageBus = new MessageBus();
// optional predicate is used as a filter for the subscription
var subscriber = messageBus.CreateSubscriber<TextMessage>(m => m.Topic=="MyTopic"); 

You can publish any BaseMessage to the bus through the public property Sender (ITargetBlock<BaseMessage>) of the bus, like this:

await messageBus.Sender.SendAsync(new TextMessage("My Message","MyTopic"));

Subscribers instances can then be used to read asynchronously from the filtered message subscription, via the public property Receiver (ISourceBlock<TextMessage> in this case), like this:

var message = await subscriber.Receiver.ReceiveAsync();