sse

Documentation

Overview

Package sse provides a dependency-free server-sent events presentation fanout adapter for runtime/contracts.

Index

• Variables
• type Hub
  • func New(options ...Option) *Hub
  • func (hub *Hub) ClientCount() int
  • func (hub *Hub) SendPresentationEvents(ctx context.Context, events []contracts.EventEnvelope) error
  • func (hub *Hub) ServeHTTP(response http.ResponseWriter, request *http.Request)
• type Option
  • func WithAudienceFromRequest(fn func(*http.Request) []string) Option
  • func WithBufferSize(size int) Option

Variables

var ErrNoHub = errors.New("sse hub cannot be nil")

ErrNoHub is returned by helpers that require a hub but receive nil.

Types

type Hub

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

Hub fans presentation events out to connected server-sent events clients.

func New

func New(options ...Option) *Hub

New creates an SSE hub.

func (*Hub) ClientCount

func (hub *Hub) ClientCount() int

ClientCount returns the number of currently connected clients.

func (*Hub) SendPresentationEvents

func (hub *Hub) SendPresentationEvents(ctx context.Context, events []contracts.EventEnvelope) error

SendPresentationEvents broadcasts presentation events to connected clients. Non-presentation events are ignored.

func (*Hub) ServeHTTP

func (hub *Hub) ServeHTTP(response http.ResponseWriter, request *http.Request)

ServeHTTP streams presentation events to one browser client.

type Option

type Option func(*Hub)

Option configures a Hub.

func WithAudienceFromRequest

func WithAudienceFromRequest(fn func(*http.Request) []string) Option

WithAudienceFromRequest assigns one or more server-owned audience labels to a connecting client. Empty labels make the client receive broadcast events only. Do not read audience labels from client-controlled query parameters without authenticating them first.

func WithBufferSize

func WithBufferSize(size int) Option

WithBufferSize sets each client's queued message buffer. Non-positive values keep the default.