pubsub

README

problem statement

lib for pub-sub style messaging

features

• API exposed via interface
• retroactive subscription
• fake implementation to allow faking interactions

event stores

Three event stores have been implemented in search of performance gains. As the performance of each may change over time, they're kept here for easy re-evaluation.

The results of reading/writing 1M events (conducted on the same machine) were as follows:

implementation	Write 1M events	Read 1M events
badgerDBEventStore	05:53	00:15
boltDBEventStore	04:09	00:28
buntDBEventStore	01:32	00:45

Documentation

Index

• type EventPublisher
• type EventStore
• type EventSubscriber
• type PubSub
  • func New(db *badger.DB) PubSub

Types

type EventPublisher

type EventPublisher interface {
	Publish(
		event model.Event,
	)
}

type EventStore

type EventStore interface {
	Add(event model.Event) error
	List(
		ctx context.Context,
		filter model.EventFilter,
	) (
		<-chan model.Event,
		<-chan error,
	)
}

type EventSubscriber

type EventSubscriber interface {
	// Subscribe returns a filtered event stream
	// events will be sent to the subscription until either:
	//  - ctx is canceled
	//  - returned channel is blocked for 10 seconds
	// note: method signature is based on https://medium.com/statuscode/pipeline-patterns-in-go-a37bb3a7e61d
	Subscribe(
		ctx context.Context,
		filter model.EventFilter,
	) (
		<-chan model.Event,
		<-chan error,
	)
}

type PubSub

type PubSub interface {
	EventPublisher
	EventSubscriber
}

func New

func New(
	db *badger.DB,
) PubSub