1 // Copyright 2023 gRPC authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include <condition_variable>
16 #include <iostream>
17 #include <memory>
18 #include <mutex>
19 #include <string>
20
21 #include "absl/flags/flag.h"
22 #include "absl/flags/parse.h"
23 #include "absl/strings/str_format.h"
24
25 #include <grpcpp/grpcpp.h>
26
27 #ifdef BAZEL_BUILD
28 #include "examples/protos/helloworld.grpc.pb.h"
29 #include "google/rpc/error_details.pb.h"
30
31 #include "src/proto/grpc/status/status.pb.h"
32 #else
33 #include "error_details.pb.h"
34 #include "helloworld.grpc.pb.h"
35 #include "status.pb.h"
36 #endif
37
38 ABSL_FLAG(std::string, target, "localhost:50051", "Server address");
39
40 using grpc::Channel;
41 using grpc::ClientContext;
42 using grpc::Status;
43 using helloworld::Greeter;
44 using helloworld::HelloReply;
45 using helloworld::HelloRequest;
46
47 class GreeterClient {
48 public:
GreeterClient(std::shared_ptr<Channel> channel)49 GreeterClient(std::shared_ptr<Channel> channel)
50 : stub_(Greeter::NewStub(channel)) {}
51
52 // Assembles the client's payload, sends it and prints the response back
53 // from the server.
SayHello(const std::string & user)54 void SayHello(const std::string& user) {
55 // Data we are sending to the server.
56 HelloRequest request;
57 request.set_name(user);
58 // Container for the data we expect from the server.
59 HelloReply reply;
60 // Context for the client. It could be used to convey extra information to
61 // the server and/or tweak certain RPC behaviors.
62 ClientContext context;
63 // The actual RPC.
64 std::mutex mu;
65 std::condition_variable cv;
66 bool done = false;
67 Status status;
68 std::cout << absl::StrFormat("### Send: SayHello(name=%s)", user)
69 << std::endl;
70 stub_->async()->SayHello(&context, &request, &reply, [&](Status s) {
71 status = std::move(s);
72 std::lock_guard<std::mutex> lock(mu);
73 done = true;
74 cv.notify_one();
75 });
76 std::unique_lock<std::mutex> lock(mu);
77 while (!done) {
78 cv.wait(lock);
79 }
80 // Handles the reply
81 if (status.ok()) {
82 std::cout << absl::StrFormat("Ok. ReplyMessage=%s", reply.message())
83 << std::endl;
84 } else {
85 std::cout << absl::StrFormat("Failed. Code=%d Message=%s",
86 status.error_code(), status.error_message())
87 << std::endl;
88 PrintErrorDetails(status);
89 }
90 }
91
PrintErrorDetails(grpc::Status status)92 void PrintErrorDetails(grpc::Status status) {
93 auto error_details = status.error_details();
94 if (error_details.empty()) {
95 return;
96 }
97 // If error_details are present in the status, this tries to deserialize
98 // those assuming they're proto messages.
99 google::rpc::Status s;
100 if (!s.ParseFromString(error_details)) {
101 std::cout << "Failed to deserialize `error_details`" << std::endl;
102 return;
103 }
104 std::cout << absl::StrFormat("Details:") << std::endl;
105 for (auto& detail : s.details()) {
106 google::rpc::QuotaFailure quota_failure;
107 if (detail.UnpackTo("a_failure)) {
108 for (auto& violation : quota_failure.violations()) {
109 std::cout << absl::StrFormat("- Quota: subject=%s description=%s",
110 violation.subject(),
111 violation.description())
112 << std::endl;
113 }
114 } else {
115 std::cout << "Unknown error_detail: " + detail.type_url() << std::endl;
116 }
117 }
118 }
119
120 private:
121 std::unique_ptr<Greeter::Stub> stub_;
122 };
123
main(int argc,char ** argv)124 int main(int argc, char** argv) {
125 absl::ParseCommandLine(argc, argv);
126 // Instantiate the client. It requires a channel, out of which the actual RPCs
127 // are created. This channel models a connection to an endpoint specified by
128 // the argument "--target=" which is the only expected argument.
129 std::string target_str = absl::GetFlag(FLAGS_target);
130 // We indicate that the channel isn't authenticated (use of
131 // InsecureChannelCredentials()).
132 GreeterClient greeter(
133 grpc::CreateChannel(target_str, grpc::InsecureChannelCredentials()));
134 // Sends a first new name, expecting OK
135 greeter.SayHello("World");
136 // Sends a duplicate name, expecting RESOURCE_EXHAUSTED with error_details
137 greeter.SayHello("World");
138 return 0;
139 }
140