bps

type Handler interface {
	Handle(SubMessage)
}

type HandlerFunc func(SubMessage)

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

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

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

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

type PubMessage struct {
	// ID is an optional message identifier.
	// It may not be supported by some implementations (then it is ignored).
	// Or may be used just to calculate partition the message.
	ID string `json:"id,omitempty"`

	// Data is the message payload.
	Data []byte `json:"data,omitempty"`

	// Attributes contains optional key-value labels.
	// It may not be supported by some implementations (then it is ignored).
	Attributes map[string]string `json:"attributes,omitempty"`
}

type PubTopic interface {
	// Publish publishes a message to the topic.
	Publish(context.Context, *PubMessage) error
}

type Publisher interface {
	// Topic returns a topic handle by name.
	Topic(name string) PubTopic
	// Close closes the producer connection.
	Close() error
}

type PublisherFactory func(context.Context, *url.URL) (Publisher, error)

type RawSubMessage []byte

type StartPosition string

type SubMessage interface {
	// Data returns raw (serialized) message data.
	Data() []byte
}

type SubOption func(*SubOptions)

type SubOptions struct {
	// StartAt defines starting position to consume messages.
	// May not be supported by some implementations.
	// Default: implementation-specific (PositionNewest is recommended).
	StartAt StartPosition
	// ErrorHandler is a subscription error handler (system/implementation-specific errors).
	// Default: log errors to STDERR.
	ErrorHandler func(error)
}

type SubTopic interface {
	// Subscribe subscribes for topic messages and handles them in background
	// till error occurs or bps.Done is returned.
	// Handler is guaranteed to be called synchronously (messages are handled one by one).
	Subscribe(handler Handler, opts ...SubOption) (Subscription, error)
}

type Subscriber interface {
	// Topic returns a subscriber topic handle.
	Topic(name string) SubTopic
	// Close closes the subscriber connection.
	Close() error
}

type SubscriberFactory func(context.Context, *url.URL) (Subscriber, error)

type Subscription interface {
	// Close stops message handling and frees resources.
	// It is safe to be called multiple times.
	Close() error
}