google::cloud::pubsub::TopicAdminClient Class Reference

Performs topic admin operations in Cloud Pub/Sub. More...

#include <google/cloud/pubsub/topic_admin_client.h>

Public Member Functions
	TopicAdminClient (std::shared_ptr< TopicAdminConnection > connection, Options opts={})
	TopicAdminClient ()=delete
	The default constructor is deleted. More...
StatusOr< google::pubsub::v1::Topic >	CreateTopic (TopicBuilder builder, Options opts={})
	Creates a new topic in Cloud Pub/Sub. More...
StatusOr< google::pubsub::v1::Topic >	CreateTopic (google::pubsub::v1::Topic request, Options opts={})
	Create a new topic in Cloud Pub/Sub. More...
StatusOr< google::pubsub::v1::Topic >	GetTopic (Topic topic, Options opts={})
	Gets information about an existing Cloud Pub/Sub topic. More...
StatusOr< google::pubsub::v1::Topic >	UpdateTopic (TopicBuilder builder, Options opts={})
	Updates the configuration of an existing Cloud Pub/Sub topic. More...
ListTopicsRange	ListTopics (std::string const &project_id, Options opts={})
	Lists all the topics for a given project id. More...
Status	DeleteTopic (Topic topic, Options opts={})
	Deletes an existing topic in Cloud Pub/Sub. More...
StatusOr< google::pubsub::v1::DetachSubscriptionResponse >	DetachSubscription (Subscription subscription, Options opts={})
	Detaches an existing subscription. More...
ListTopicSubscriptionsRange	ListTopicSubscriptions (Topic const &topic, Options opts={})
	Lists all the subscription names for a given topic. More...
ListTopicSnapshotsRange	ListTopicSnapshots (Topic const &topic, Options opts={})
	Lists all the subscription names for a given topic. More...

Detailed Description

Performs topic admin operations in Cloud Pub/Sub.

Applications use this class to perform operations on Cloud Pub/Sub.

Performance

TopicAdminClient objects are cheap to create, copy, and move. However, each TopicAdminClient object must be created with a std::shared_ptr<TopicAdminConnection>, which itself is relatively expensive to create. Therefore, connection instances should be shared when possible. See the MakeTopicAdminConnection() function and the TopicAdminConnection interface for more details.

Thread Safety

Instances of this class created via copy-construction or copy-assignment share the underlying pool of connections. Access to these copies via multiple threads is guaranteed to work. Two threads operating on the same instance of this class is not guaranteed to work.

Error Handling

This class uses StatusOr<T> to report errors. When an operation fails to perform its work the returned StatusOr<T> contains the error details. If the ok() member function in the StatusOr<T> returns true then it contains the expected result. Please consult the `StatusOr<T>` documentation for more details.

Constructor & Destructor Documentation

TopicAdminClient() [1/2]

google::cloud::pubsub::TopicAdminClient::TopicAdminClient ( std::shared_ptr< TopicAdminConnection >  connection, Options  opts = {}  )

explicit

TopicAdminClient() [2/2]

google::cloud::pubsub::TopicAdminClient::TopicAdminClient ( )

delete

The default constructor is deleted.

Use PublisherClient(std::shared_ptr<PublisherConnection>)

Member Function Documentation

CreateTopic() [1/2]

StatusOr< google::pubsub::v1::Topic > google::cloud::pubsub::TopicAdminClient::CreateTopic ( google::pubsub::v1::Topic  request, Options  opts = {}  )

inline

Create a new topic in Cloud Pub/Sub.

CreateTopic() [2/2]

StatusOr< google::pubsub::v1::Topic > google::cloud::pubsub::TopicAdminClient::CreateTopic ( TopicBuilder  builder, Options  opts = {}  )

inline

Creates a new topic in Cloud Pub/Sub.

Idempotency

This operation is idempotent, as it succeeds only once, therefore the library retries the call. It might return a status code of kAlreadyExists as a consequence of retrying a successful (but reported as failed) request.

Example

  namespace pubsub = ::google::cloud::pubsub;
  [](pubsub::TopicAdminClient client, std::string project_id,
     std::string topic_id) {
    auto topic = client.CreateTopic(pubsub::TopicBuilder(
        pubsub::Topic(std::move(project_id), std::move(topic_id))));
    // Note that kAlreadyExists is a possible error when the library retries.
    if (topic.status().code() == google::cloud::StatusCode::kAlreadyExists) {
      std::cout << "The topic already exists\n";
      return;
    }
    if (!topic) throw std::move(topic).status();
 
    std::cout << "The topic was successfully created: " << topic->DebugString()
              << "\n";
  }

Parameters

builder	the configuration for the new topic, includes the name.
opts	Override the class-level options, such as retry and backoff policies.

DeleteTopic()

Status google::cloud::pubsub::TopicAdminClient::DeleteTopic ( Topic  topic, Options  opts = {}  )

inline

Deletes an existing topic in Cloud Pub/Sub.

Idempotency

This operation is idempotent, the state of the system is the same after one or several calls, and therefore it is always retried. It might return a status code of kNotFound as a consequence of retrying a successful (but reported as failed) request.

Example

  namespace pubsub = ::google::cloud::pubsub;
  [](pubsub::TopicAdminClient client, std::string const& project_id,
     std::string const& topic_id) {
    auto status = client.DeleteTopic(
        pubsub::Topic(std::move(project_id), std::move(topic_id)));
    // Note that kNotFound is a possible result when the library retries.
    if (status.code() == google::cloud::StatusCode::kNotFound) {
      std::cout << "The topic was not found\n";
      return;
    }
    if (!status.ok()) throw std::runtime_error(status.message());
 
    std::cout << "The topic was successfully deleted\n";
  }

Parameters

topic	the name of the topic to be deleted.
opts	Override the class-level options, such as retry and backoff policies.

DetachSubscription()

StatusOr< google::pubsub::v1::DetachSubscriptionResponse > google::cloud::pubsub::TopicAdminClient::DetachSubscription ( Subscription  subscription, Options  opts = {}  )

inline

Detaches an existing subscription.

This operation stops the subscription from receiving any further messages, it drops any messages still retained by the subscription, and any outstanding pull requests will fail with kFailedPrecondition.

Idempotency

This operation is idempotent, the state of the system is the same after one or several calls, and therefore it is always retried.

Example

  namespace pubsub = ::google::cloud::pubsub;
  [](pubsub::TopicAdminClient client, std::string project_id,
     std::string subscription_id) {
    auto response = client.DetachSubscription(pubsub::Subscription(
        std::move(project_id), std::move(subscription_id)));
    if (!response.ok()) throw std::move(response).status();
 
    std::cout << "The subscription was successfully detached: "
              << response->DebugString() << "\n";
  }

Parameters

subscription	the name of the subscription to detach.
opts	Override the class-level options, such as retry and backoff policies.

GetTopic()

StatusOr< google::pubsub::v1::Topic > google::cloud::pubsub::TopicAdminClient::GetTopic ( Topic  topic, Options  opts = {}  )

inline

Gets information about an existing Cloud Pub/Sub topic.

Idempotency

This is a read-only operation and therefore always idempotent and retried.

Example

  namespace pubsub = ::google::cloud::pubsub;
  [](pubsub::TopicAdminClient client, std::string project_id,
     std::string topic_id) {
    auto topic = client.GetTopic(
        pubsub::Topic(std::move(project_id), std::move(topic_id)));
    if (!topic) throw std::move(topic).status();
 
    std::cout << "The topic information was successfully retrieved: "
              << topic->DebugString() << "\n";
  }

ListTopics()

ListTopicsRange google::cloud::pubsub::TopicAdminClient::ListTopics ( std::string const &  project_id, Options  opts = {}  )

inline

Lists all the topics for a given project id.

Idempotency

This is a read-only operation and therefore always idempotent and retried.

Example

  namespace pubsub = ::google::cloud::pubsub;
  [](pubsub::TopicAdminClient client, std::string const& project_id) {
    int count = 0;
    for (auto& topic : client.ListTopics(project_id)) {
      if (!topic) throw std::move(topic).status();
      std::cout << "Topic Name: " << topic->name() << "\n";
      ++count;
    }
    if (count == 0) {
      std::cout << "No topics found in project " << project_id << "\n";
    }
  }

ListTopicSnapshots()

ListTopicSnapshotsRange google::cloud::pubsub::TopicAdminClient::ListTopicSnapshots ( Topic const &  topic, Options  opts = {}  )

inline

Lists all the subscription names for a given topic.

Note

The returned range contains fully qualified snapshot names, e.g., "projects/my-project/snapshots/my-subscription". Applications may need to parse these names to use with other APIs.

Idempotency

This is a read-only operation and therefore always idempotent and retried.

Example

  namespace pubsub = ::google::cloud::pubsub;
  [](pubsub::TopicAdminClient client, std::string project_id,
     std::string topic_id) {
    auto const topic =
        pubsub::Topic(std::move(project_id), std::move(topic_id));
    std::cout << "Snapshot list for topic " << topic << ":\n";
    for (auto& name : client.ListTopicSnapshots(topic)) {
      if (!name) throw std::move(name).status();
      std::cout << "  " << *name << "\n";
    }
  }

See also

https://cloud.google.com/pubsub/docs/replay-overview for a detailed description of Cloud Pub/Sub's snapshots.

ListTopicSubscriptions()

ListTopicSubscriptionsRange google::cloud::pubsub::TopicAdminClient::ListTopicSubscriptions ( Topic const &  topic, Options  opts = {}  )

inline

Lists all the subscription names for a given topic.

Note

The returned range contains fully qualified subscription names, e.g., "projects/my-project/subscriptions/my-subscription". Applications may need to parse these names to use with other APIs.

Idempotency

This is a read-only operation and therefore always idempotent and retried.

Example

  namespace pubsub = ::google::cloud::pubsub;
  [](pubsub::TopicAdminClient client, std::string project_id,
     std::string topic_id) {
    auto const topic =
        pubsub::Topic(std::move(project_id), std::move(topic_id));
    std::cout << "Subscription list for topic " << topic << ":\n";
    for (auto& name : client.ListTopicSubscriptions(topic)) {
      if (!name) throw std::move(name).status();
      std::cout << "  " << *name << "\n";
    }
  }

UpdateTopic()

StatusOr< google::pubsub::v1::Topic > google::cloud::pubsub::TopicAdminClient::UpdateTopic ( TopicBuilder  builder, Options  opts = {}  )

inline

Updates the configuration of an existing Cloud Pub/Sub topic.

Idempotency

This operation is idempotent, the state of the system is the same after one or several calls, and therefore it is always retried.

Example

  namespace pubsub = ::google::cloud::pubsub;
  [](pubsub::TopicAdminClient client, std::string project_id,
     std::string topic_id) {
    auto topic = client.UpdateTopic(
        pubsub::TopicBuilder(
            pubsub::Topic(std::move(project_id), std::move(topic_id)))
            .add_label("test-key", "test-value"));
    if (!topic) throw std::move(topic).status();
 
    std::cout << "The topic was successfully updated: " << topic->DebugString()
              << "\n";
  }

Parameters

builder	the configuration for the new topic, includes the name.
opts	Override the class-level options, such as retry and backoff policies.