gcppubsub

package main

import (
	"context"
	"log"

	"gocloud.dev/pubsub"

	raw "cloud.google.com/go/pubsub/apiv1"
	pb "cloud.google.com/go/pubsub/apiv1/pubsubpb"
)

func main() {
	ctx := context.Background()

	// Construct a *pubsub.Subscription, in this example using a URL.
	const subName = "projects/myprojectID/subscriptions/example-subscription"
	subscription, err := pubsub.OpenSubscription(ctx, "gcppubsub://"+subName)
	if err != nil {
		log.Fatal(err)
	}
	defer func() { _ = subscription.Shutdown(ctx) }()

	// Get the underlying SubscriberClient. If you used the constructor to create
	// the subscription (e.g., gcppubsub.OpenSubscriptionByPath), you may already
	// have the client.
	var client *raw.SubscriberClient
	if !subscription.As(&client) {
		log.Fatal("Couldn't get SubscriberClient using As")
	}

	// Now assume you've got a message, and processing is going to take a long time;
	// you want to extend the default Ack deadline.
	msg, err := subscription.Receive(ctx)
	if err != nil {
		log.Fatalf("Failed to receive message: %v", err)
	}

	// Get the underlying ReceivedMessage.
	var rm *pb.ReceivedMessage
	if !msg.As(&rm) {
		log.Fatal("Couldn't get ReceivedMessage using As")
	}

	// Call ModifyAckDeadline.
	if err := client.ModifyAckDeadline(ctx, &pb.ModifyAckDeadlineRequest{
		Subscription:       subName,
		AckIds:             []string{rm.AckId},
		AckDeadlineSeconds: 30 * 60, // 30m, or whatever you need
	}); err != nil {
		log.Fatalf("Failed to ModifyAckDeadline: %v", err)
	}
	// ... eventually Ack the message.
	msg.Ack()
}

Output:

package main

import (
	"context"
	"log"

	"gocloud.dev/pubsub"
)

func main() {
	// PRAGMA: This example is used on gocloud.dev; PRAGMA comments adjust how it is shown and can be ignored.
	// PRAGMA: On gocloud.dev, add a blank import: _ "gocloud.dev/pubsub/gcppubsub"
	// PRAGMA: On gocloud.dev, hide lines until the next blank line.
	ctx := context.Background()

	subscription, err := pubsub.OpenSubscription(ctx,
		"gcppubsub://projects/my-project/subscriptions/my-subscription")
	if err != nil {
		log.Fatal(err)
	}
	defer func() { _ = subscription.Shutdown(ctx) }()
}

Output:

package main

import (
	"context"
	"log"

	"gocloud.dev/pubsub"
)

func main() {
	// PRAGMA: This example is used on gocloud.dev; PRAGMA comments adjust how it is shown and can be ignored.
	// PRAGMA: On gocloud.dev, add a blank import: _ "gocloud.dev/pubsub/gcppubsub"
	// PRAGMA: On gocloud.dev, hide lines until the next blank line.
	ctx := context.Background()

	topic, err := pubsub.OpenTopic(ctx, "gcppubsub://projects/myproject/topics/mytopic")
	if err != nil {
		log.Fatal(err)
	}
	defer func() { _ = topic.Shutdown(ctx) }()
}

Output: