micro/broker/broker.go
2019-07-07 12:44:09 +01:00

70 lines
1.6 KiB
Go

// Package broker is an interface used for asynchronous messaging
package broker
// Broker is an interface used for asynchronous messaging.
type Broker interface {
Init(...Option) error
Options() Options
Connect() error
Disconnect() error
Publish(topic string, m *Message, opts ...PublishOption) error
Subscribe(topic string, h Handler, opts ...SubscribeOption) (Subscriber, error)
String() string
}
// Handler is used to process messages via a subscription of a topic.
// The handler is passed a publication interface which contains the
// message and optional Ack method to acknowledge receipt of the message.
type Handler func(Event) error
type Message struct {
Header map[string]string
Body []byte
}
// Event is given to a subscription handler for processing
type Event interface {
Topic() string
Message() *Message
Ack() error
}
// Subscriber is a convenience return type for the Subscribe method
type Subscriber interface {
Options() SubscribeOptions
Topic() string
Unsubscribe() error
}
var (
DefaultBroker Broker = newHttpBroker()
)
func NewBroker(opts ...Option) Broker {
return newHttpBroker(opts...)
}
func Init(opts ...Option) error {
return DefaultBroker.Init(opts...)
}
func Connect() error {
return DefaultBroker.Connect()
}
func Disconnect() error {
return DefaultBroker.Disconnect()
}
func Publish(topic string, msg *Message, opts ...PublishOption) error {
return DefaultBroker.Publish(topic, msg, opts...)
}
func Subscribe(topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
return DefaultBroker.Subscribe(topic, handler, opts...)
}
func String() string {
return DefaultBroker.String()
}