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Diffstat (limited to 'examples/cpp/load_balancing/greeter_client.cc')
-rw-r--r-- | examples/cpp/load_balancing/greeter_client.cc | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/examples/cpp/load_balancing/greeter_client.cc b/examples/cpp/load_balancing/greeter_client.cc new file mode 100644 index 0000000000..5b08204a96 --- /dev/null +++ b/examples/cpp/load_balancing/greeter_client.cc @@ -0,0 +1,90 @@ +/* + * + * Copyright 2015 gRPC authors. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + */ + +#include <iostream> +#include <memory> +#include <string> + +#include <grpcpp/grpcpp.h> + +#ifdef BAZEL_BUILD +#include "examples/protos/helloworld.grpc.pb.h" +#else +#include "helloworld.grpc.pb.h" +#endif + +using grpc::Channel; +using grpc::ChannelArguments; +using grpc::ClientContext; +using grpc::Status; +using helloworld::HelloRequest; +using helloworld::HelloReply; +using helloworld::Greeter; + +class GreeterClient { + public: + 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 actual RPC. + Status status = stub_->SayHello(&context, request, &reply); + + // Act upon its status. + if (status.ok()) { + return reply.message(); + } else { + std::cout << status.error_code() << ": " << status.error_message() + << std::endl; + return "RPC failed"; + } + } + + private: + 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()). + ChannelArguments args; + // Set the load balancing policy for the channel. + args.SetLoadBalancingPolicyName("round_robin"); + GreeterClient greeter(grpc::CreateCustomChannel( + "localhost:50051", grpc::InsecureChannelCredentials(), args)); + std::string user("world"); + std::string reply = greeter.SayHello(user); + std::cout << "Greeter received: " << reply << std::endl; + + return 0; +} |