grpc/cpp/helloworld/greeter_async_client.cc

/*
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#include <iostream>
#include <memory>
#include <string>

#include <grpc/grpc.h>
#include <grpc/support/log.h>
#include <grpc++/async_unary_call.h>
#include <grpc++/channel_arguments.h>
#include <grpc++/channel_interface.h>
#include <grpc++/client_context.h>
#include <grpc++/completion_queue.h>
#include <grpc++/create_channel.h>
#include <grpc++/credentials.h>
#include <grpc++/status.h>
#include "helloworld.grpc.pb.h"

using grpc::ChannelArguments;
using grpc::ChannelInterface;
using grpc::ClientAsyncResponseReader;
using grpc::ClientContext;
using grpc::CompletionQueue;
using grpc::Status;
using helloworld::HelloRequest;
using helloworld::HelloReply;
using helloworld::Greeter;

class GreeterClient {
 public:
  explicit GreeterClient(std::shared_ptr<ChannelInterface> channel)
      : stub_(Greeter::NewStub(channel)) {}

  std::string SayHello(const std::string& user) {
    HelloRequest request;
    request.set_name(user);
    HelloReply reply;
    ClientContext context;
    CompletionQueue cq;
    Status status;

    std::unique_ptr<ClientAsyncResponseReader<HelloReply> > rpc(
        stub_->AsyncSayHello(&context, request, &cq, (void*)1));
    void* got_tag;
    bool ok;
    cq.Next(&got_tag, &ok);
    GPR_ASSERT(ok);
    GPR_ASSERT(got_tag == (void*)1);

    rpc->Finish(&reply, &status, (void*)2);
    cq.Next(&got_tag, &ok);
    GPR_ASSERT(ok);
    GPR_ASSERT(got_tag == (void*)2);

    if (status.IsOk()) {
      return reply.message();
    } else {
      return "Rpc failed";
    }
  }

  void Shutdown() { stub_.reset(); }

 private:
  std::unique_ptr<Greeter::Stub> stub_;
};

int main(int argc, char** argv) {
  grpc_init();

  GreeterClient greeter(grpc::CreateChannel(
      "localhost:50051", grpc::InsecureCredentials(), ChannelArguments()));
  std::string user("world");
  std::string reply = greeter.SayHello(user);
  std::cout << "Greeter received: " << reply << std::endl;

  greeter.Shutdown();

  grpc_shutdown();
}