bus

Documentation

Overview

Package bus implements a message bus which is a common data model and a messaging infrastructure to allow different modules to communicate locally or remotely.

Index

• Variables
• type Bus
  • func NewBus() *Bus
  • func (b *Bus) Close()
  • func (b *Bus) Publish(topic Topic, message ...Message) (Future, error)
  • func (b *Bus) Subscribe(topic Topic, listener MessageListener) error
• type Future
• type Message
  • func NewMessage(id MessageID, data interface{}) Message
  • func (m Message) Data() interface{}
  • func (m Message) ID() MessageID
• type MessageID
• type MessageListener
• type Publisher
• type Subscriber
• type Topic
  • func BiTopic(id string) Topic
  • func UniTopic(id string) Topic

Variables

var (
	// ErrTopicNotExist hints the topic published doesn't exist.
	ErrTopicNotExist = errors.New("the topic does not exist")
)

Types

type Bus

type Bus struct {
	// contains filtered or unexported fields
}

The Bus allows publish-subscribe-style communication between components.

func NewBus

func NewBus() *Bus

NewBus returns a Bus.

func (*Bus) Close

func (b *Bus) Close()

Close a Bus until all Messages are sent to Subscribers.

func (*Bus) Publish

func (b *Bus) Publish(topic Topic, message ...Message) (Future, error)

Publish sends Messages to a Topic.

func (*Bus) Subscribe

func (b *Bus) Subscribe(topic Topic, listener MessageListener) error

Subscribe adds an MessageListener to be called when a message of a Topic is posted.

type Future

type Future interface {
	Get() (Message, error)
	GetAll() ([]Message, error)
}

Future represents a future result of an asynchronous publishing.

type Message

type Message struct {
	// contains filtered or unexported fields
}

Message is send on the bus to all subscribed listeners.

func NewMessage

func NewMessage(id MessageID, data interface{}) Message

NewMessage returns a new Message with a MessageID and embed data.

func (Message) Data

func (m Message) Data() interface{}

Data returns the data wrapped in the Message.

func (Message) ID

func (m Message) ID() MessageID

ID outputs the MessageID of the Message.

type MessageID

type MessageID uint64

MessageID the identity of a Message.

type MessageListener

type MessageListener interface {
	Rev(message Message) Message
}

MessageListener is the signature of functions that can handle an EventMessage.

type Publisher

type Publisher interface {
	Publish(topic Topic, message ...Message) (Future, error)
}

Publisher allow sending Messages to a Topic.

type Subscriber

type Subscriber interface {
	Subscribe(topic Topic, listener MessageListener) error
}

Subscriber allow subscribing a Topic's messages.

type Topic

type Topic struct {
	// contains filtered or unexported fields
}

Topic is the object which messages are sent to or received from.

func BiTopic

func BiTopic(id string) Topic

BiTopic returns bidirectional Topic.

func UniTopic

func UniTopic(id string) Topic

UniTopic returns an unary Topic.