C++ example of PubSub grpc pull operations

normal_pull.cpp

#include <iostream>
#include <memory>

#include <grpc++/grpc++.h>
#include <grpc++/client_context.h>
#include <grpc++/create_channel.h>
#include <grpc++/security/credentials.h>
#include <grpc++/support/status.h>
#include <grpc/grpc.h>
#include <grpcpp/grpcpp.h>
#include <grpcpp/security/credentials.h>

#include "google/pubsub/v1/pubsub.grpc.pb.h"
#include "google/pubsub/v1/pubsub.pb.h"

auto main() -> int {

    using grpc::ClientContext;
    using google::pubsub::v1::Publisher;
    using google::pubsub::v1::PublishRequest;
    using google::pubsub::v1::PublishResponse;
    using google::pubsub::v1::PubsubMessage;
    using google::pubsub::v1::Subscriber;
    using google::pubsub::v1::Subscription;
    using google::pubsub::v1::ReceivedMessage;

    auto json = "{}";
    auto jwt = grpc::ServiceAccountJWTAccessCredentials(json, 3600);
    auto creds = CompositeChannelCredentials(SslCredentials(grpc::SslCredentialsOptions()), jwt);

    ClientContext ctx;
    auto sub = std::make_unique<Subscriber::Stub>(grpc::CreateChannel("pubsub.googleapis.com", creds));

    auto const sub_string = "projects/test/subscriptions/test-subscription";
    PullRequest pullRequest;
    pullRequest.set_subscription(sub_string);
    pullRequest.set_max_messages(100);

    PullResponse pullResponse;

    const grpc::Status &pull = sub->Pull(&ctx, pullRequest, &pullResponse);

    for(auto&m :pullResponse.received_messages()){
        std::cout <<m.message().data()
                  <<+" ID: "+m.message().message_id()
                  <<+" ACK ID:"+m.ack_id()+"\n";
    }

    std::cout << pullResponse.received_messages_size();

    if (!pull.ok()) {
        std::cout << "Pulling message failed with error " + std::to_string(pull.error_code()) + ": " +
                     pull.error_message() << '\n';
    }

}

streaming_pull.cpp

#include <iostream>
#include <memory>

#include <grpc++/grpc++.h>
#include <grpc++/client_context.h>
#include <grpc++/create_channel.h>
#include <grpc++/security/credentials.h>
#include <grpc++/support/status.h>
#include <grpc/grpc.h>
#include <grpcpp/grpcpp.h>
#include <grpcpp/security/credentials.h>

#include "google/pubsub/v1/pubsub.grpc.pb.h"
#include "google/pubsub/v1/pubsub.pb.h"


auto main() -> int {

    using grpc::ClientContext;
    using google::pubsub::v1::Publisher;
    using google::pubsub::v1::PubsubMessage;
    using google::pubsub::v1::Subscriber;
    using google::pubsub::v1::Subscription;
    using google::pubsub::v1::ReceivedMessage;
    using google::pubsub::v1::StreamingPullRequest;
    using google::pubsub::v1::StreamingPullResponse;
    using grpc::Status;

    auto json = "{}";


    auto jwt = grpc::ServiceAccountJWTAccessCredentials(json, 3600);
    auto creds = CompositeChannelCredentials(SslCredentials(grpc::SslCredentialsOptions()), jwt);

    ClientContext ctx;

    auto sub = std::make_unique<Subscriber::Stub>(grpc::CreateChannel("pubsub.googleapis.com", creds));
    auto const sub_string = "projects/test/subscriptions/test-subscription";

    StreamingPullRequest pullRequest;
    pullRequest.set_subscription(sub_string);

    auto pull = sub->StreamingPull(&ctx);

    pull->Write(pullRequest);
    pull->WritesDone();

    StreamingPullResponse pullResponse;
    while (pull->Read(&pullResponse)) {

        std::cout << "PULLING\n\n";
        std::cout << pullResponse.received_messages_size();

        for (auto &m : pullResponse.received_messages()) {
            std::cout << m.message().data()
                      << +" ID: " + m.message().message_id()
                      << +" ACK ID:" + m.ack_id() + "\n";
        }
    }

    Status status = pull->Finish();
    if (!status.ok()) {
        std::cout << "Pulling message failed with error " + std::to_string(status.error_code()) + ": " +
                     status.error_message() << '\n';
    }
}