subscriber sample

pstest_subscriber.go

package pubsub

import (
	"context"
	"fmt"

	"cloud.google.com/go/pubsub"
	"google.golang.org/api/option"
)

type Subscriber struct {
	client *pubsub.Client
}

func NewSubscriber(ctx context.Context, projectID string, opts ...option.ClientOption) (*Subscriber, error) {
	client, err := pubsub.NewClient(ctx, projectID, opts...)
	if err != nil {
		return nil, err
	}
	return &Subscriber{
		client: client,
	}, nil
}

func (s *Subscriber) Receive(ctx context.Context, subID string) error {
	cctx, cancel := context.WithCancel(ctx)
	sub := s.client.Subscription(subID)
	err := sub.Receive(cctx, func(ctx context.Context, m *pubsub.Message) {
		fmt.Printf("Got message: %s\n", m.Data)
		m.Ack()
		cancel()
	})
	if err != context.Canceled {
		return err
	}
	return nil
}