eventstream

Documentation

Overview

Package eventstream implements a publisher / subscriber.

Index

• func Publish(event interface{})
• func Unsubscribe(sub *Subscription)
• type EventStream
  • func (ps *EventStream) Publish(evt interface{})
  • func (es *EventStream) Subscribe(fn func(evt interface{})) *Subscription
  • func (ps *EventStream) Unsubscribe(sub *Subscription)
• type Predicate
• type Subscription
  • func Subscribe(fn func(evt interface{})) *Subscription
  • func (s *Subscription) WithPredicate(p Predicate) *Subscription

Examples

• Subscribe

Functions

func Publish

func Publish(event interface{})

func Unsubscribe

func Unsubscribe(sub *Subscription)

Types

type EventStream

type EventStream struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

func (*EventStream) Publish

func (ps *EventStream) Publish(evt interface{})

func (*EventStream) Subscribe

func (es *EventStream) Subscribe(fn func(evt interface{})) *Subscription

func (*EventStream) Unsubscribe

func (ps *EventStream) Unsubscribe(sub *Subscription)

type Predicate

type Predicate func(evt interface{}) bool

Predicate is a function used to filter messages before being forwarded to a subscriber

type Subscription

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

Subscription is returned from the Subscribe function.

This value and can be passed to Unsubscribe when the observer is no longer interested in receiving messages

func Subscribe

func Subscribe(fn func(evt interface{})) *Subscription

Example

Subscribe subscribes to events

package main

import (
	"fmt"

	"github.com/aergoio/aergo-actor/eventstream"
)

func main() {
	sub := eventstream.Subscribe(func(event interface{}) {
		fmt.Println(event)
	})

	// only allow strings
	sub.WithPredicate(func(evt interface{}) bool {
		_, ok := evt.(string)
		return ok
	})

	eventstream.Publish("Hello World")
	eventstream.Publish(1)

	eventstream.Unsubscribe(sub)

}

Output:

Hello World

func (*Subscription) WithPredicate

func (s *Subscription) WithPredicate(p Predicate) *Subscription

WithPredicate sets a predicate to filter messages passed to the subscriber