1 /*
2 *
3 * Copyright 2024 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 <grpc/grpc.h>
20 #include <grpcpp/ext/proto_server_reflection_plugin.h>
21 #include <grpcpp/grpcpp.h>
22
23 #include <iostream>
24 #include <string>
25
26 #include "absl/flags/flag.h"
27 #include "absl/flags/parse.h"
28
29 #ifdef BAZEL_BUILD
30 #include "examples/protos/helloworld.grpc.pb.h"
31 #else
32 #include "helloworld.grpc.pb.h"
33 #endif
34
35 ABSL_FLAG(std::string, target, "localhost:50051", "Server address");
36 ABSL_FLAG(size_t, quota, 20,
37 "Resource quota (in megabytes) that defines how much memory gRPC has "
38 "available for buffers");
39
40 namespace {
41
42 class Reader final : public grpc::ClientReadReactor<helloworld::HelloReply> {
43 public:
Start()44 void Start() {
45 StartRead(&res_);
46 StartCall();
47 }
48
WaitForDone()49 grpc::Status WaitForDone() {
50 absl::MutexLock lock(&mu_);
51 mu_.Await(absl::Condition(
52 +[](Reader* reader) { return reader->result_.has_value(); }, this));
53 return *result_;
54 }
55
OnReadDone(bool ok)56 void OnReadDone(bool ok) override {
57 if (!ok) {
58 std::cout << "Done reading\n";
59 return;
60 }
61 std::cout << "Read " << res_.message().length() << " bytes.\n";
62 res_.set_message("");
63 // A delay to slow down the client so it can't read responses quick enough
64 sleep(1);
65 StartRead(&res_);
66 }
67
OnDone(const grpc::Status & status)68 void OnDone(const grpc::Status& status) override {
69 absl::MutexLock lock(&mu_);
70 result_ = status;
71 }
72
73 private:
74 absl::Mutex mu_;
75 absl::optional<grpc::Status> result_;
76 helloworld::HelloReply res_;
77 };
78
79 } // namespace
80
main(int argc,char * argv[])81 int main(int argc, char* argv[]) {
82 absl::ParseCommandLine(argc, argv);
83 grpc::ChannelArguments channel_arguments;
84 grpc::ResourceQuota quota;
85 quota.Resize(absl::GetFlag(FLAGS_quota) * 1024 * 1024);
86 channel_arguments.SetResourceQuota(quota);
87 auto channel = grpc::CreateCustomChannel(absl::GetFlag(FLAGS_target),
88 grpc::InsecureChannelCredentials(),
89 channel_arguments);
90 auto greeter = helloworld::Greeter::NewStub(channel);
91 grpc::ClientContext ctx;
92 helloworld::HelloRequest req;
93 req.set_name("World");
94 Reader reader;
95 greeter->async()->SayHelloStreamReply(&ctx, &req, &reader);
96 reader.Start();
97 auto status = reader.WaitForDone();
98 if (status.ok()) {
99 std::cout << "Success\n";
100 } else {
101 std::cerr << "Failed with error: " << status.error_message() << "\n";
102 }
103 return 0;
104 }
105