msgbus

type DefaultSubscriber struct{}

type Message struct {
	Topic   Topic
	Payload interface{}
}

type MessageBus interface {
	// A subscriber register on s specific topic.
	// When a message on this topic is published, the subscriber's OnMessage() is called.
	Register(topic Topic, sub Subscriber)
	// UnRegister unregister the subscriber from message bus.
	UnRegister(topic Topic, sub Subscriber)
	// Used to publish a message on this message bus to notify subscribers.
	Publish(topic Topic, payload interface{})
	// Used to publish a message on this message bus to notify subscribers.
	// Safe mode, make sure the subscriber's OnMessage() is called with the order of a message on this topic is published.
	PublishSafe(topic Topic, payload interface{})
	// Used to publish a message on this message bus to notify subscribers.
	// Sync mod, make sure all messages  are completed sequentially.
	PublishSync(topic Topic, payload interface{})
	// Close the message bus, all publishes are ignored.
	Close()
}

type Subscriber interface {
	// When a message with topic A is published on the message bus,
	// all the subscribers's OnMessage() methods of topic A are called.
	OnMessage(*Message)

	// When the message bus is shutting down,
	OnQuit()
}

type Topic int