utils

type MessageHandler func(msg []byte) error

type PubSub interface {
	Publisher
	Subscriber
}

type Publisher interface {
	// Publishes message to the stream.
	Publish(topic, subtopic string, msg []byte) error
}

type Subscriber interface {
	// Subscribe subscribes to the message stream and consumes messages.
	Subscribe(topic string, handler MessageHandler) error

	// Unsubscribe unsubscribes from the message stream and
	// stops consuming messages.
	Unsubscribe(topic string) error
}