1 /*
2 *
3 * Copyright 2021 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19 #include <grpcpp/ext/proto_server_reflection_plugin.h>
20 #include <grpcpp/grpcpp.h>
21 #include <grpcpp/health_check_service_interface.h>
22
23 #include <cstddef>
24 #include <cstdint>
25 #include <iostream>
26 #include <string>
27
28 #include "absl/flags/flag.h"
29 #include "absl/flags/parse.h"
30 #include "absl/strings/str_format.h"
31
32 #ifdef BAZEL_BUILD
33 #include "examples/protos/helloworld.grpc.pb.h"
34 #else
35 #include "helloworld.grpc.pb.h"
36 #endif
37
38 ABSL_FLAG(uint16_t, port, 50051, "Server port for the service");
39 ABSL_FLAG(size_t, quota, 20, "Resource quota, in megabytes");
40
41 namespace {
42
43 //
44 // Server reactor that is slow to read incoming messages, causing the buffers
45 // to fill.
46 //
47 class SlowReadingBidiReactor final
48 : public grpc::ServerBidiReactor<helloworld::HelloRequest,
49 helloworld::HelloReply> {
50 public:
SlowReadingBidiReactor()51 SlowReadingBidiReactor() { StartRead(&req_); }
52
OnReadDone(bool ok)53 void OnReadDone(bool ok) override {
54 std::cout << "Recieved request with " << req_.name().length()
55 << " bytes name\n";
56 if (!ok) {
57 Finish(grpc::Status::OK);
58 return;
59 }
60 sleep(1);
61 StartRead(&req_);
62 }
63
OnDone()64 void OnDone() override {
65 std::cout << "Done\n";
66 delete this;
67 }
68
69 private:
70 absl::Mutex mu_;
71 helloworld::HelloRequest req_;
72 };
73
74 // Logic and data behind the server's behavior.
75 class GreeterServiceImpl final : public helloworld::Greeter::CallbackService {
76 grpc::ServerBidiReactor<helloworld::HelloRequest, helloworld::HelloReply>*
SayHelloBidiStream(grpc::CallbackServerContext *)77 SayHelloBidiStream(grpc::CallbackServerContext* /* context */) override {
78 return new SlowReadingBidiReactor();
79 }
80 };
81
82 } // namespace
83
RunServer(uint16_t port)84 void RunServer(uint16_t port) {
85 std::string server_address = absl::StrFormat("0.0.0.0:%d", port);
86 GreeterServiceImpl service;
87
88 grpc::EnableDefaultHealthCheckService(true);
89 grpc::reflection::InitProtoReflectionServerBuilderPlugin();
90 grpc::ServerBuilder builder;
91 // Listen on the given address without any authentication mechanism.
92 builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());
93 // Register "service" as the instance through which we'll communicate with
94 // clients. In this case it corresponds to an *synchronous* service.
95 builder.RegisterService(&service);
96 grpc::ResourceQuota quota;
97 quota.Resize(absl::GetFlag(FLAGS_quota) * 1024 * 1024);
98 // Finally assemble the server.
99 auto server = builder.BuildAndStart();
100 std::cout << "Server listening on " << server_address << std::endl;
101
102 // Wait for the server to shutdown. Note that some other thread must be
103 // responsible for shutting down the server for this call to ever return.
104 server->Wait();
105 }
106
main(int argc,char ** argv)107 int main(int argc, char** argv) {
108 absl::ParseCommandLine(argc, argv);
109 RunServer(absl::GetFlag(FLAGS_port));
110 return 0;
111 }
112