| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include <iostream> |
| #include <memory> |
| #include <string> |
| |
| #include <grpc++/grpc++.h> |
| |
| #include "helloworld.grpc.pb.h" |
| |
| using grpc::Channel; |
| 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<Channel> channel) |
| : stub_(Greeter::NewStub(channel)) {} |
| |
| // Assembles the client's payload, sends it and presents the response back |
| // from the server. |
| std::string SayHello(const std::string& user) { |
| // Data we are sending to the server. |
| HelloRequest request; |
| request.set_name(user); |
| |
| // Container for the data we expect from the server. |
| HelloReply reply; |
| |
| // Context for the client. It could be used to convey extra information to |
| // the server and/or tweak certain RPC behaviors. |
| ClientContext context; |
| |
| // The producer-consumer queue we use to communicate asynchronously with the |
| // gRPC runtime. |
| CompletionQueue cq; |
| |
| // Storage for the status of the RPC upon completion. |
| Status status; |
| |
| // stub_->AsyncSayHello() performs the RPC call, returning an instance we |
| // store in "rpc". Because we are using the asynchronous API, we need to |
| // hold on to the "rpc" instance in order to get updates on the ongoing RPC. |
| std::unique_ptr<ClientAsyncResponseReader<HelloReply> > rpc( |
| stub_->AsyncSayHello(&context, request, &cq)); |
| |
| // Request that, upon completion of the RPC, "reply" be updated with the |
| // server's response; "status" with the indication of whether the operation |
| // was successful. Tag the request with the integer 1. |
| rpc->Finish(&reply, &status, (void*)1); |
| void* got_tag; |
| bool ok = false; |
| // Block until the next result is available in the completion queue "cq". |
| // The return value of Next should always be checked. This return value |
| // tells us whether there is any kind of event or the cq_ is shutting down. |
| GPR_ASSERT(cq.Next(&got_tag, &ok)); |
| |
| // Verify that the result from "cq" corresponds, by its tag, our previous |
| // request. |
| GPR_ASSERT(got_tag == (void*)1); |
| // ... and that the request was completed successfully. Note that "ok" |
| // corresponds solely to the request for updates introduced by Finish(). |
| GPR_ASSERT(ok); |
| |
| // Act upon the status of the actual RPC. |
| if (status.ok()) { |
| return reply.message(); |
| } else { |
| return "RPC failed"; |
| } |
| } |
| |
| private: |
| // Out of the passed in Channel comes the stub, stored here, our view of the |
| // server's exposed services. |
| std::unique_ptr<Greeter::Stub> stub_; |
| }; |
| |
| int main(int argc, char** argv) { |
| // Instantiate the client. It requires a channel, out of which the actual RPCs |
| // are created. This channel models a connection to an endpoint (in this case, |
| // localhost at port 50051). We indicate that the channel isn't authenticated |
| // (use of InsecureChannelCredentials()). |
| GreeterClient greeter(grpc::CreateChannel( |
| "localhost:50051", grpc::InsecureChannelCredentials())); |
| std::string user("world"); |
| std::string reply = greeter.SayHello(user); // The actual RPC call! |
| std::cout << "Greeter received: " << reply << std::endl; |
| |
| return 0; |
| } |