brpc/example/cancel_c++/client.cpp
2022-12-14 20:13:26 +08:00

130 lines
5.1 KiB
C++

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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.
// A client to send 2 requests to server and accept the first returned response.
#include <gflags/gflags.h>
#include <butil/logging.h>
#include <butil/time.h>
#include <brpc/channel.h>
#include "echo.pb.h"
DEFINE_string(protocol, "baidu_std", "Protocol type. Defined in src/brpc/options.proto");
DEFINE_string(connection_type, "", "Connection type. Available values: single, pooled, short");
DEFINE_string(server, "0.0.0.0:8000", "IP Address of server");
DEFINE_string(load_balancer, "", "The algorithm for load balancing");
DEFINE_int32(timeout_ms, 100, "RPC timeout in milliseconds");
DEFINE_int32(max_retry, 3, "Max retries(not including the first RPC)");
// A special done for canceling another RPC.
class CancelRPC : public google::protobuf::Closure {
public:
explicit CancelRPC(brpc::CallId rpc_id) : _rpc_id(rpc_id) {}
void Run() {
brpc::StartCancel(_rpc_id);
}
private:
brpc::CallId _rpc_id;
};
int main(int argc, char* argv[]) {
// Parse gflags. We recommend you to use gflags as well.
GFLAGS_NS::ParseCommandLineFlags(&argc, &argv, true);
// A Channel represents a communication line to a Server. Notice that
// Channel is thread-safe and can be shared by all threads in your program.
brpc::Channel channel;
// Initialize the channel, NULL means using default options.
brpc::ChannelOptions options;
options.protocol = FLAGS_protocol;
options.connection_type = FLAGS_connection_type;
options.timeout_ms = FLAGS_timeout_ms/*milliseconds*/;
options.max_retry = FLAGS_max_retry;
if (channel.Init(FLAGS_server.c_str(), FLAGS_load_balancer.c_str(), &options) != 0) {
LOG(ERROR) << "Fail to initialize channel";
return -1;
}
// Normally, you should not call a Channel directly, but instead construct
// a stub Service wrapping it. stub can be shared by all threads as well.
example::EchoService_Stub stub(&channel);
// Send a request and wait for the response every 1 second.
int log_id = 0;
while (!brpc::IsAskedToQuit()) {
example::EchoRequest request1;
example::EchoResponse response1;
brpc::Controller cntl1;
example::EchoRequest request2;
example::EchoResponse response2;
brpc::Controller cntl2;
request1.set_message("hello1");
request2.set_message("hello2");
cntl1.set_log_id(log_id ++); // set by user
cntl2.set_log_id(log_id ++);
const brpc::CallId id1 = cntl1.call_id();
const brpc::CallId id2 = cntl2.call_id();
CancelRPC done1(id2);
CancelRPC done2(id1);
butil::Timer tm;
tm.start();
// Send 2 async calls and join them. They will cancel each other in
// their done which is run before the RPC being Join()-ed. Canceling
// a finished RPC has no effect.
// For example:
// Time RPC1 RPC2
// 1 response1 comes back.
// 2 running done1.
// 3 cancel RPC2
// 4 running done2 (NOTE: done also runs)
// 5 cancel RPC1 (no effect)
stub.Echo(&cntl1, &request1, &response1, &done1);
stub.Echo(&cntl2, &request2, &response2, &done2);
brpc::Join(id1);
brpc::Join(id2);
tm.stop();
if (cntl1.Failed() && cntl2.Failed()) {
LOG(WARNING) << "Both failed. rpc1:" << cntl1.ErrorText()
<< ", rpc2: " << cntl2.ErrorText();
} else if (!cntl1.Failed()) {
LOG(INFO) << "Received `" << response1.message() << "' from rpc1="
<< id1.value << '@' << cntl1.remote_side()
<< " latency=" << tm.u_elapsed() << "us"
<< " rpc1_latency=" << cntl1.latency_us() << "us"
<< " rpc2_latency=" << cntl2.latency_us() << "us";
} else {
LOG(INFO) << "Received `" << response2.message() << "' from rpc2="
<< id2.value << '@' << cntl2.remote_side()
<< " latency=" << tm.u_elapsed() << "us"
<< " rpc1_latency=" << cntl1.latency_us() << "us"
<< " rpc2_latency=" << cntl2.latency_us() << "us";
}
sleep(1);
}
LOG(INFO) << "EchoClient is going to quit";
return 0;
}