Documentation
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Overview ¶
Package eventbus provides application-owned, typed event subscriptions.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrOverflow = errors.New("eventbus: subscriber capacity exceeded")
Functions ¶
This section is empty.
Types ¶
type Bus ¶
type Bus[T any] struct { // contains filtered or unexported fields }
func (*Bus[T]) Subscribe ¶
func (b *Bus[T]) Subscribe(handler func(T)) func()
Subscribe preserves synchronous delivery. Handlers run outside the bus lock and must synchronize their own state when producers emit concurrently.
func (*Bus[T]) SubscribeAsync ¶
func (b *Bus[T]) SubscribeAsync(opts SubscribeOptions[T], handler func(T) error) (*Subscription[T], error)
func (*Bus[T]) SubscribeFiltered ¶
SubscribeFiltered preserves synchronous delivery for consumers that need an immediate visibility boundary (for example a journal before a file switch). Use SubscribeAsync for independently bounded, non-blocking consumers.
type SubscribeOptions ¶
type SubscribeOptions[T any] struct { Filter func(T) bool Buffer int MaxBytes int64 Size func(T) int64 Clone func(T) T OnError func(error) OnDrop func(uint64) }
SubscribeOptions bounds pending events, including the executing handler. Filter, Size and Clone run on the producer and must be fast. Clone transfers ownership before Emit returns. Other subscribers must treat events as immutable. OnError and OnDrop run on the worker, never on the producer. Callbacks must not wait on this subscription's Done or Close. Filter, Size and Clone must not reenter the subscription (including Err/Cancel).
type Subscription ¶
type Subscription[T any] struct { // contains filtered or unexported fields }
Subscription owns a serial worker. Cancel discards queued work; an admitted handler may finish. Close drains admitted work. Blocking handlers must observe their own cancellation context; the bus cannot interrupt user code.
func (*Subscription[T]) Cancel ¶
func (s *Subscription[T]) Cancel()
func (*Subscription[T]) Close ¶
func (s *Subscription[T]) Close(ctx context.Context) error
Close stops admission and waits for admitted work and callbacks to finish.
func (*Subscription[T]) Done ¶
func (s *Subscription[T]) Done() <-chan struct{}
func (*Subscription[T]) Err ¶
func (s *Subscription[T]) Err() error
func (*Subscription[T]) Stopped ¶
func (s *Subscription[T]) Stopped() <-chan struct{}
Stopped closes as soon as admission stops, even if the handler is blocked.
Source Files