backend

Documentation

Index

• type ConsumerDispatcher
• type EventProducer
• type Info
• type Interface
• type Subscribable

Types

type ConsumerDispatcher

type ConsumerDispatcher func(event *cloudevents.Event)

ConsumerDispatcher receives CloudEvents to be delivered to subscribers. The consumer dispatcher must process the event for all subscriptions, including retries and dead leter queues. When the function finishes executing the backend will consider the event processed and will make sure it is not re-delivered.

type EventProducer

type EventProducer interface {
	// Ingest a new CloudEvents at the backend.
	Produce(context.Context, *cloudevents.Event) error
}

type Info

type Info struct {
	// Name of the backend implementation
	Name string
}

type Interface

type Interface interface {
	EventProducer
	Subscribable

	// Info returns information about the backend implementation.
	Info() *Info

	// Init connects and does initialization tasks at the backend.
	// It must be called before using other methods (but Info)
	// and might perform initialization tasks like creating structures
	// or migrations.
	Init(ctx context.Context) error

	// Start is a blocking method that read events from the backend
	// and pass them to the subscriber's consumer dispatcher. When the consumer
	// dispatcher returns, the message is marked as processed and
	// won't be delivered anymore.
	// When the context is done all subscribers are finished and the
	// method exists.
	Start(ctx context.Context) error

	// Probe checks the overall status of the backend implementation.
	Probe(context.Context) error
}

type Subscribable

type Subscribable interface {
	// Subscribe is a method that sets up a reader that will retrieve
	// events from the backend and pass them to the consumer dispatcher.
	// When the consumer dispatcher returns, the message is marked as
	// processed and won't be delivered anymore.
	Subscribe(name string, ccb ConsumerDispatcher) error

	// Unsubscribe is a method that removes a subscription referencing
	// it by name, returning when all pending (already read) messages
	// have been dispatched.
	Unsubscribe(name string)
}