gRPC-demo/controller/greeter_server.cpp
2025-01-14 14:50:41 +01:00

107 lines
3.4 KiB
C++

/*
*
* 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 "absl/flags/flag.h"
#include "absl/flags/parse.h"
#include "absl/strings/str_format.h"
#include "hello_world.pb.h"
#include <grpcpp/server_context.h>
#include <grpcpp/support/server_callback.h>
#include <grpcpp/support/status.h>
#include <grpcpp/ext/proto_server_reflection_plugin.h>
#include <grpcpp/grpcpp.h>
#include <grpcpp/health_check_service_interface.h>
#ifdef BAZEL_BUILD
#include "examples/protos/helloworld.grpc.pb.h"
#else
#include "hello_world.grpc.pb.h"
#endif
void RunServer(uint16_t port);
using grpc::Server;
using grpc::ServerBuilder;
ABSL_FLAG(uint16_t, port, 50051, "Server port for the service");
// This is the implementation of the actual service;
// We elect to implement this as a callback server (preferred implementation)
class GreeterServiceImpl final : public Greeter::CallbackService {
public:
// We only reply with a single message back, thus we use a unary reactor
grpc::ServerUnaryReactor *
SayHello([[maybe_unused]] grpc::CallbackServerContext *context,
const HelloRequest *request, HelloReply *reply) override {
// To be able to handle more fancy things, we elect to implement our own
// reactor
class HelloReactor : public grpc::ServerUnaryReactor {
public:
HelloReactor(const HelloRequest &request, const std::string &prefix,
HelloReply *reply) {
reply->set_message(prefix + request.name());
Finish(grpc::Status::OK);
}
private:
void OnDone() override {
std::cout << "RPC completed." << std::endl;
delete this;
}
void OnCancel() override { std::cerr << "RPC cancelled." << std::endl; }
};
return new HelloReactor(*request, "Hello ", reply);
}
};
void RunServer(uint16_t port) {
std::string server_address = absl::StrFormat("0.0.0.0:%d", port);
GreeterServiceImpl service;
grpc::EnableDefaultHealthCheckService(true);
grpc::reflection::InitProtoReflectionServerBuilderPlugin();
ServerBuilder builder;
// Listen on the given address without any authentication mechanism.
builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());
// Register "service" as the instance through which we'll communicate with
// clients. In this case it corresponds to an *synchronous* service.
builder.RegisterService(&service);
// Finally assemble the server.
std::unique_ptr<Server> server(builder.BuildAndStart());
std::cout << "Server listening on " << server_address << std::endl;
// Wait for the server to shutdown. Note that some other thread must be
// responsible for shutting down the server for this call to ever return.
server->Wait();
}
int main(int argc, char **argv) {
absl::ParseCommandLine(argc, argv);
RunServer(absl::GetFlag(FLAGS_port));
return 0;
}