Lite Event Aggregator and IPC Tranporter

Lite.EventIPC is a cross-platform local Event Aggregator and remote IPC service library for C#. The pattern is used for decoupling publishers and subscribers in a single or multiple applications. The library can be easily extended for custom IPC transports using the IEventTransport interface to suit your needs (need I say, DBus?)

The Event Aggregator service in C# pattern is useful for decoupling publishers and subscribers in an application.

Features

This implementation is features:

• Simple and thread-safe
• Uses weak references to avoid memory leaks
• Cleans up dead references during Publish.
• Prevents memory leaks when subscribers are no longer needed.
• DI-friendly with extensions and hosted service
• Optional IPC transport mechanisms for inter-process communication (IPC) with JSON serialization:
  • Named Pipe Transport
  • Memory-Mapped File Transport (Windows OS only)
  • TCP/IP Transport
• 2 types of IPC communication:
  • One-way publish/subscribe (IEventTransport)
  • (COMING SOON) Bidirectional request/response with timeouts (IEventEnvelopeTransport)

Usage

public class UserCreatedEvent
{
  public string UserName { get; set; }
}


static void Main()
{
  var eventAggregator = new EventAggregator();

  // Subscribe
  eventAggregator.Subscribe<UserCreatedEvent>(e =>
    Console.WriteLine($"User created: {e.Username}"));

  // Publish
  eventAggregator.Publish(new UserCreatedEvent { Username = "Damian" })
}

Architecture

Why Weak References

If you store strong references to handlers, subscribers will never be collected. Using WeakReference ensures that if the subscriber is no longer needed, it can be GC'd.

History

v1.1.0

• Option to include Microsoft.Extensions.Logger for deep-logging

Future Considerations

• Send IPC only for specified event types.
• Possibly, filtering or priority-based dispatching.
• Refactor IEventTransport toIIpcEvent for clarity.
• Refactor Transporter namespace to Ipc or IpcTransport for clarity.
• Refactor IEventEnvelopeTransport under IpcReceipted namespace for clarity.
• Security: Named Pipes, MMF, and TCP should use proper ACLs / TLS / auth in production