Cloud Pub/Sub C++ Client Library

The Cloud Pub/Sub C++ Client library offers types and functions to use Cloud Pub/Sub from C++ applications.

Quickstart

The following "Hello World" program should give you a sense of how to use the library.

#include "google/cloud/pubsub/publisher.h"
#include <iostream>
int main(int argc, char* argv[]) try {
 if (argc != 3) {
 std::cerr << "Usage: " << argv[0] << " <project-id> <topic-id>\n";
 return 1;
 }
 std::string const project_id = argv[1];
 std::string const topic_id = argv[2];
 // Create a namespace alias to make the code easier to read.
 namespace pubsub = ::google::cloud::pubsub;
 auto publisher = pubsub::Publisher(
 pubsub::MakePublisherConnection(pubsub::Topic(project_id, topic_id)));
 auto id =
 publisher
 .Publish(pubsub::MessageBuilder{}.SetData("Hello World!").Build())
 .get();
 if (!id) throw std::move(id).status();
 std::cout << "Hello World published with id=" << *id << "\n";
 return 0;
} catch (google::cloud::Status const& status) {
 std::cerr << "google::cloud::Status thrown: " << status << "\n";
 return 1;
}

More Information

• Publisher::Publish() - to efficiently publish Pub/Sub messages.
• BlockingPublisher::Publish() - to publish a single Pub/Sub messages.
• Subscriber::Subscribe() - to asynchronous receive Pub/Sub messages.
• Subscriber::Pull() - to receive a single Pub/Sub messages.
• Error Handling to learn how the library reports run-time errors.
• Environment Variables for environment variables affecting the library. Some of these environment variables enable logging to the console. This can be an effective approach to diagnose runtime problems.
• Override the default endpoint
• Override the authentication configuration
• Override Retry, Backoff, and Idempotency Policies
• Override the default universe domain
• Testing your Cloud Pub/Sub publisher application with googlemock shows how to write tests mocking Publisher
• Testing your Cloud Pub/Sub subscriber application with googlemock shows how to write tests mocking Subscriber
• The Setting up your development environment guide describes how to set up a C++ development environment in various platforms, including the Google Cloud C++ client libraries.