broker

Documentation

Overview

Package broker contains message broker abstraction and NATS JetStream broker implementation.

Index

• type Broker
• type Message
• type NatsJetStream
  • func NewNatsJetStream(client nats.JetStreamContext, config *NatsJetStreamConfig) *NatsJetStream
  • func (b *NatsJetStream) Exit()
  • func (b *NatsJetStream) Pub(data []byte) error
  • func (b *NatsJetStream) Sub() (<-chan Message, error)
• type NatsJetStreamConfig

Types

type Broker

type Broker interface {
	// Sub subscribes to broker and returns a channel to receive messages.
	Sub() (<-chan Message, error)
	// Pub synchronously publishes a message to broker.
	Pub([]byte) error
	// Exit gracefully shuts down subscriber.
	Exit()
}

Broker defines common broker methods.

type Message

type Message struct {
	Data       []byte
	Ack        func()
	InProgress func()
}

Message contains data from the broker.

type NatsJetStream

type NatsJetStream struct {
	Debug func(s string)
	// contains filtered or unexported fields
}

NatsJetStream implements Broker interface for NATS JetStream broker. Exported field Debug can be used for debugging.

func NewNatsJetStream

func NewNatsJetStream(client nats.JetStreamContext, config *NatsJetStreamConfig) *NatsJetStream

NewNatsJetStream creates new NATS JetStream broker implementing broker.Broker interface.

func (*NatsJetStream) Exit

func (b *NatsJetStream) Exit()

Exit implements broker.Broker interface.

func (*NatsJetStream) Pub

func (b *NatsJetStream) Pub(data []byte) error

Pub implements broker.Broker interface.

func (*NatsJetStream) Sub

func (b *NatsJetStream) Sub() (<-chan Message, error)

Sub implements broker.Broker interface.

type NatsJetStreamConfig

type NatsJetStreamConfig struct {
	// Consume this subject
	ConsumeSubject string
	// Optional. If provided, queue group will be used.
	ConsumerGroup string
	// Produce into this subject
	ProduceSubject string
	// ReceiveChannelSize will prevent dropping messages caused by th slow consumer.
	ReceiveChannelSize int
	// How long to wait for ACK. If crossed, message will be redelivered. Default 60.s
	AckWait time.Duration
	// MaxRedeliveries defines how many times message will be redelivered if not acknowledged. Default 2.
	MaxRedeliveries uint8
}

NatsJetStreamConfig contains NatsJetStream configuration parameters.