mpubsub

type BatchConsumerFunc ¶

type BatchConsumerFunc func(context.Context, []*Message) (bool, error)

BatchConsumerFunc is similar to ConsumerFunc, except it takes in a batch of multiple messages at once. If the boolean returned will apply to every message in the batch.

type BatchGroupFunc ¶

type BatchGroupFunc func(a, b *Message) bool

BatchGroupFunc is an optional param to BatchConsume which allows for grouping messages into separate groups. Each message received is attempted to be placed in a group. Grouping is done by calling this function with the received message and a random message from a group, and if this function returns true then the received message is placed into that group. If this returns false for all groups then a new group is created.

This function should be a pure function.

type ConsumerFunc ¶

type ConsumerFunc func(context.Context, *Message) (bool, error)

ConsumerFunc is a function which messages being consumed will be passed. The returned boolean and returned error are independent. If the bool is false the message will be returned to the queue for retrying later. If an error is returned it will be logged.

The Context will be canceled once the deadline has been reached (as set when Consume is called).

type ConsumerOpts ¶

type ConsumerOpts struct {
	// Default 30s. The timeout each message has to complete before its context
	// is cancelled and the server re-publishes it
	Timeout time.Duration

	// Default 1. Number of concurrent messages to consume at a time
	Concurrent int
}

ConsumerOpts are options which effect the behavior of a Consume method call

type Message ¶

type Message = pubsub.Message

Message aliases the type in the official driver

type PubSub ¶

type PubSub struct {
	*pubsub.Client
	// contains filtered or unexported fields
}

PubSub is a wrapper around a pubsub client providing more functionality.

func InstPubSub(cmp *mcmp.Component, options ...PubSubOpt) *PubSub

func (ps *PubSub) Topic(ctx context.Context, name string, create bool) (*Topic, error)

type PubSubOpt ¶

type PubSubOpt func(*pubsubOpts)

PubSubOpt is a value which adjusts the behavior of InstPubSub.

func PubSubGCE(gce *mdb.GCE) PubSubOpt

type Subscription ¶

type Subscription struct {
	*Topic
	Name string
	// contains filtered or unexported fields
}

Subscription provides methods around a subscription to a topic in PubSub

func (s *Subscription) BatchConsume(
	ctx context.Context,
	fn BatchConsumerFunc, gfn BatchGroupFunc,
	opts ConsumerOpts,
)

func (s *Subscription) Consume(ctx context.Context, fn ConsumerFunc, opts ConsumerOpts)

type Topic ¶

type Topic struct {
	*PubSub
	Name string
	// contains filtered or unexported fields
}

Topic provides methods around a particular topic in PubSub

func (t *Topic) Publish(ctx context.Context, data []byte) error

func (t *Topic) Subscription(ctx context.Context, name string, create bool) (*Subscription, error)