Golang pubsub.Client類代碼示例

func delete(client *pubsub.Client, topic string) error {
	ctx := context.Background()
	// [START delete_topic]
	t := client.Topic(topic)
	if err := t.Delete(ctx); err != nil {
		return err
	}
	fmt.Printf("Deleted topic: %v\n", t)
	// [END delete_topic]
	return nil
}

func create(client *pubsub.Client, topic string) error {
	ctx := context.Background()
	// [START create_topic]
	t, err := client.CreateTopic(ctx, topic)
	if err != nil {
		return err
	}
	fmt.Printf("Topic created: %v\n", t)
	// [END create_topic]
	return nil
}

func getPolicy(c *pubsub.Client, topicName string) *iam.Policy {
	ctx := context.Background()

	// [START pubsub_get_topic_policy]
	policy, err := c.Topic(topicName).IAM().Policy(ctx)
	if err != nil {
		log.Fatal(err)
	}
	for _, role := range policy.Roles() {
		log.Print(policy.Members(role))
	}
	// [END pubsub_get_topic_policy]
	return policy
}

func publish(client *pubsub.Client, topic, msg string) error {
	ctx := context.Background()
	// [START publish]
	t := client.Topic(topic)
	msgIDs, err := t.Publish(ctx, &pubsub.Message{
		Data: []byte(msg),
	})
	if err != nil {
		return err
	}
	for _, id := range msgIDs {
		fmt.Printf("Published a message; msg ID: %v\n", id)
	}
	// [END publish]
	return nil
}

func testPermissions(c *pubsub.Client, topicName string) []string {
	ctx := context.Background()

	// [START pubsub_test_topic_permissions]
	topic := c.Topic(topicName)
	perms, err := topic.IAM().TestPermissions(ctx, []string{
		"pubsub.topics.publish",
		"pubsub.topics.update",
	})
	if err != nil {
		log.Fatal(err)
	}
	for _, perm := range perms {
		log.Printf("Allowed: %v", perm)
	}
	// [END pubsub_test_topic_permissions]
	return perms
}

func list(client *pubsub.Client) ([]*pubsub.Subscription, error) {
	ctx := context.Background()
	// [START get_all_subscriptions]
	var subs []*pubsub.Subscription
	it := client.Subscriptions(ctx)
	for {
		s, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return nil, err
		}
		subs = append(subs, s)
	}
	// [END get_all_subscriptions]
	return subs, nil
}

func createTopicIfNotExists(c *pubsub.Client) *pubsub.Topic {
	ctx := context.Background()

	const topic = "example-topic"
	// Create a topic to subscribe to.
	t := c.Topic(topic)
	ok, err := t.Exists(ctx)
	if err != nil {
		log.Fatal(err)
	}
	if ok {
		return t
	}

	t, err = c.CreateTopic(ctx, topic)
	if err != nil {
		log.Fatalf("Failed to create the topic: %v", err)
	}
	return t
}

func addUsers(c *pubsub.Client, topicName string) {
	ctx := context.Background()

	// [START pubsub_set_topic_policy]
	topic := c.Topic(topicName)
	policy, err := topic.IAM().Policy(ctx)
	if err != nil {
		log.Fatalf("GetPolicy: %v", err)
	}
	// Other valid prefixes are "serviceAccount:", "user:"
	// See the documentation for more values.
	policy.Add(iam.AllUsers, iam.Viewer)
	policy.Add("group:[email protected]", iam.Editor)
	if err := topic.IAM().SetPolicy(ctx, policy); err != nil {
		log.Fatalf("SetPolicy: %v", err)
	}
	// NOTE: It may be necessary to retry this operation if IAM policies are
	// being modified concurrently. SetPolicy will return an error if the policy
	// was modified since it was retrieved.
	// [END pubsub_set_topic_policy]
}

func pullMsgs(client *pubsub.Client, name string, topic *pubsub.Topic) error {
	ctx := context.Background()

	// publish 10 messages on the topic.
	for i := 0; i < 10; i++ {
		_, err := topic.Publish(ctx, &pubsub.Message{
			Data: []byte(fmt.Sprintf("hello world #%d", i)),
		})
		if err != nil {
			return err
		}
	}

	// [START pull_messages]
	sub := client.Subscription(name)
	it, err := sub.Pull(ctx)
	if err != nil {
		return err
	}
	defer it.Stop()

	// Consume 10 messages.
	for i := 0; i < 10; i++ {
		msg, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return err
		}
		fmt.Printf("Got message: %q\n", string(msg.Data))
		msg.Done(true)
	}
	// [END pull_messages]
	return nil
}