natsio/jetstream_pubsub.go

56 lines
1.4 KiB
Go

package natsio
import (
"errors"
"fmt"
"github.com/nats-io/nats.go"
)
// Publish ...
func (js JetStream) Publish(stream, subject string, payload []byte) error {
channel := combineStreamAndSubjectName(stream, subject)
_, err := js.instance.PublishAsync(channel, payload)
if err != nil {
msg := fmt.Sprintf("[NATS JETSTREAM] - publish message to subject #%s error: %s", channel, err.Error())
return errors.New(msg)
}
return nil
}
// Subscribe ...
func (js JetStream) Subscribe(stream, subject string, cb nats.MsgHandler) (*nats.Subscription, error) {
channel := combineStreamAndSubjectName(stream, subject)
sub, err := js.instance.Subscribe(channel, cb)
if err != nil {
msg := fmt.Sprintf("[NATS JETSTREAM] - subscribe subject %s error: %s", channel, err.Error())
return nil, errors.New(msg)
}
return sub, nil
}
// PullSubscribe ...
//
// Example:
//
// sub, err := natsio.PullSubscribe("A_STREAM", "A_OBJECT")
//
// for {
// messages, err := sub.Fetch(10)
// // process each messages
// }
//
func (js JetStream) PullSubscribe(stream, subject string) (*nats.Subscription, error) {
channel := combineStreamAndSubjectName(stream, subject)
sub, err := js.instance.PullSubscribe(stream, subject)
if err != nil {
msg := fmt.Sprintf("[NATS JETSTREAM] - pull subscribe subject #%s error: %s", channel, err.Error())
return nil, errors.New(msg)
}
return sub, nil
}