broker

type Action int

type Handler func(ctx context.Context, m Message) Action

type Message struct {

	// ID is the unique event id; consumers dedupe on it. Defaults to a fresh
	// UUID at publish time when empty.
	ID string
	// Type is the CloudEvents type, e.g. "widget.created".
	Type string
	// Source identifies the producer; a publisher fills it from its configured
	// source when empty.
	Source string
	// Subject is the optional CloudEvents subject.
	Subject string
	// Time is the event timestamp; defaults to now at publish time when zero.
	Time time.Time
	// DataContentType is the MIME type of Data, e.g. "application/json".
	DataContentType string
	// Data is the business payload (NOT the envelope).
	Data []byte

	// Exchange is the target exchange (AMQP) or topic namespace.
	Exchange string
	// RoutingKey routes the message within the exchange.
	RoutingKey string
	// Headers are transport headers (e.g. W3C trace context).
	Headers map[string]string
}

type Publisher interface {
	// Publish delivers m. Implementations should provide at-least-once
	// semantics (e.g. AMQP publisher confirms) so callers can treat a nil error
	// as durably accepted by the broker.
	Publish(ctx context.Context, m Message) error
	// Close releases publisher resources.
	Close() error
}