1 /*
2 * Copyright 2014 Google Inc. All rights reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <thread>
18
19 #include <grpc++/grpc++.h>
20
21 #include "monster_test_generated.h"
22 #include "monster_test.grpc.fb.h"
23
24 using namespace MyGame::Example;
25
26 // The callback implementation of our server, that derives from the generated
27 // code. It implements all rpcs specified in the FlatBuffers schema.
28 class ServiceImpl final : public MyGame::Example::MonsterStorage::Service {
Store(::grpc::ServerContext * context,const flatbuffers::grpc::Message<Monster> * request,flatbuffers::grpc::Message<Stat> * response)29 virtual ::grpc::Status Store(::grpc::ServerContext* context,
30 const flatbuffers::grpc::Message<Monster> *request,
31 flatbuffers::grpc::Message<Stat> *response)
32 override {
33 // Create a response from the incoming request name.
34 fbb_.Clear();
35 auto stat_offset = CreateStat(fbb_, fbb_.CreateString("Hello, " +
36 request->GetRoot()->name()->str()));
37 fbb_.Finish(stat_offset);
38 // Transfer ownership of the message to gRPC
39 *response = fbb_.ReleaseMessage<Stat>();
40 return grpc::Status::OK;
41 }
Retrieve(::grpc::ServerContext * context,const flatbuffers::grpc::Message<Stat> * request,::grpc::ServerWriter<flatbuffers::grpc::Message<Monster>> * writer)42 virtual ::grpc::Status Retrieve(::grpc::ServerContext *context,
43 const flatbuffers::grpc::Message<Stat> *request,
44 ::grpc::ServerWriter< flatbuffers::grpc::Message<Monster>>* writer)
45 override {
46
47 for (int i=0; i<10; i++) {
48 fbb_.Clear();
49 // Create 10 monsters for resposne.
50 auto monster_offset =
51 CreateMonster(fbb_, 0, 0, 0, fbb_.CreateString(
52 request->GetRoot()->id()->str() + " No." + std::to_string(i)));
53 fbb_.Finish(monster_offset);
54
55 flatbuffers::grpc::Message<Monster> monster = fbb_.ReleaseMessage<Monster>();
56
57 // Send monster to client using streaming.
58 writer->Write(monster);
59 }
60 return grpc::Status::OK;
61 }
62
63 private:
64 flatbuffers::grpc::MessageBuilder fbb_;
65 };
66
67 // Track the server instance, so we can terminate it later.
68 grpc::Server *server_instance = nullptr;
69 // Mutex to protec this variable.
70 std::mutex wait_for_server;
71 std::condition_variable server_instance_cv;
72
73 // This function implements the server thread.
RunServer()74 void RunServer() {
75 auto server_address = "0.0.0.0:50051";
76 // Callback interface we implemented above.
77 ServiceImpl service;
78 grpc::ServerBuilder builder;
79 builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());
80 builder.RegisterService(&service);
81
82 // Start the server. Lock to change the variable we're changing.
83 wait_for_server.lock();
84 server_instance = builder.BuildAndStart().release();
85 wait_for_server.unlock();
86 server_instance_cv.notify_one();
87
88 std::cout << "Server listening on " << server_address << std::endl;
89 // This will block the thread and serve requests.
90 server_instance->Wait();
91 }
92
main(int,const char * [])93 int main(int /*argc*/, const char * /*argv*/[]) {
94 // Launch server.
95 std::thread server_thread(RunServer);
96
97 // wait for server to spin up.
98 std::unique_lock<std::mutex> lock(wait_for_server);
99 while (!server_instance) server_instance_cv.wait(lock);
100
101 // Now connect the client.
102 auto channel = grpc::CreateChannel("localhost:50051",
103 grpc::InsecureChannelCredentials());
104 auto stub = MyGame::Example::MonsterStorage::NewStub(channel);
105
106
107 flatbuffers::grpc::MessageBuilder fbb;
108 {
109 grpc::ClientContext context;
110 // Build a request with the name set.
111 auto monster_offset = CreateMonster(fbb, 0, 0, 0, fbb.CreateString("Fred"));
112 fbb.Finish(monster_offset);
113 auto request = fbb.ReleaseMessage<Monster>();
114 flatbuffers::grpc::Message<Stat> response;
115
116 // The actual RPC.
117 auto status = stub->Store(&context, request, &response);
118
119 if (status.ok()) {
120 auto resp = response.GetRoot()->id();
121 std::cout << "RPC response: " << resp->str() << std::endl;
122 } else {
123 std::cout << "RPC failed" << std::endl;
124 }
125 }
126 {
127 grpc::ClientContext context;
128 fbb.Clear();
129 auto stat_offset = CreateStat(fbb, fbb.CreateString("Fred"));
130 fbb.Finish(stat_offset);
131 auto request = fbb.ReleaseMessage<Stat>();
132
133 flatbuffers::grpc::Message<Monster> response;
134 auto stream = stub->Retrieve(&context, request);
135 while (stream->Read(&response)) {
136 auto resp = response.GetRoot()->name();
137 std::cout << "RPC Streaming response: " << resp->str() << std::endl;
138 }
139 }
140
141 #if !FLATBUFFERS_GRPC_DISABLE_AUTO_VERIFICATION
142 {
143 // Test that an invalid request errors out correctly
144 grpc::ClientContext context;
145 flatbuffers::grpc::Message<Monster> request; // simulate invalid message
146 flatbuffers::grpc::Message<Stat> response;
147 auto status = stub->Store(&context, request, &response);
148 // The rpc status should be INTERNAL to indicate a verification error. This
149 // matches the protobuf gRPC status code for an unparseable message.
150 assert(!status.ok());
151 assert(status.error_code() == ::grpc::StatusCode::INTERNAL);
152 assert(strcmp(status.error_message().c_str(), "Message verification failed") == 0);
153 }
154 #endif
155
156 server_instance->Shutdown();
157
158 server_thread.join();
159
160 delete server_instance;
161
162 return 0;
163 }
164