eventbus

Straightforward EventBus for Go 1.18+

Go Version Support

Go 1.18+ is required, due to the use of generics

Project Status

Unlike some of my other projects that are used in production (eg. ensure for testing and erk for errors), this project is currently more on the experimental side. It has good test coverage, but I haven't actually built anything serious with it (yet!). So, please use at your own risk! Oh, and if you do use it for something serious, let me know how it works out!

Install

Library

$ go get github.com/JosiahWitt/eventbus

About

This package provides a straightforward concurrent, typed EventBus for Go 1.18+, supporting fanout, and in order, only once delivery.

Examples

Please see the examples directory for complete examples, such as the Simple Chat App.

Basic Usage

type Message struct { Body string }

bus := eventbus.New[*Message]()

// In one goroutine:
sub := bus.Subscribe("chatroom:123", "user:456")
for msg := range sub.Channel() {
  // Do something with msg
}
// Eventually...
sub.Unsubscribe()

// In another goroutine:
bus.Publish(&Message{Body: "Hello, World!"}, "chatroom:123", "user:789")
bus.Publish(&Message{Body: "Go is fun!"}, "chatroom:456", "user:456")
bus.Publish(&Message{Body: "Wordle 1/6"}, "chatroom:456", "user:789")
bus.Publish(&Message{Body: "Bonjour!"}, "chatroom:123", "user:456")

// sub will receive:
//  1. Hello, World!
//  2. Go is fun!
//  3. Bonjour!
// Each of those messages is published to one or both of `chatroom:123` and `user:456`.
//
// sub will not receive "Wordle 1/6", because that was published to neither `chatroom:123` nor `user:456`.