81 lines
1.9 KiB
Go
81 lines
1.9 KiB
Go
package broker
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// Broker is an interface used for asynchronous messaging.
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// Its an abstraction over various message brokers
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// {NATS, RabbitMQ, Kafka, ...}
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type Broker interface {
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Options() Options
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Address() string
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Connect() error
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Disconnect() error
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Init(...Option) error
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Publish(string, *Message, ...PublishOption) error
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Subscribe(string, Handler, ...SubscribeOption) (Subscriber, error)
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String() string
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}
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// Handler is used to process messages via a subscription of a topic.
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// The handler is passed a publication interface which contains the
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// message and optional Ack method to acknowledge receipt of the message.
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type Handler func(Publication) error
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type Message struct {
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Header map[string]string
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Body []byte
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}
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// Publication is given to a subscription handler for processing
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type Publication interface {
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Topic() string
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Message() *Message
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Ack() error
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}
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// Subscriber is a convenience return type for the Subscribe method
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type Subscriber interface {
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Options() SubscribeOptions
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Topic() string
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Unsubscribe() error
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}
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// Codec is used for encoding where the broker doesn't natively support
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// headers in the message type. In this case the entire message is
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// encoded as the payload
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type Codec interface {
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Marshal(interface{}) ([]byte, error)
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Unmarshal([]byte, interface{}) error
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String() string
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}
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var (
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DefaultBroker Broker = newHttpBroker()
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)
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func NewBroker(opts ...Option) Broker {
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return newHttpBroker(opts...)
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}
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func Init(opts ...Option) error {
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return DefaultBroker.Init(opts...)
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}
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func Connect() error {
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return DefaultBroker.Connect()
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}
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func Disconnect() error {
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return DefaultBroker.Disconnect()
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}
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func Publish(topic string, msg *Message, opts ...PublishOption) error {
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return DefaultBroker.Publish(topic, msg, opts...)
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}
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func Subscribe(topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
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return DefaultBroker.Subscribe(topic, handler, opts...)
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}
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func String() string {
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return DefaultBroker.String()
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}
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