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// Copyright (c) 2014 Baidu, Inc.
//
// Licensed 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 sending requests to server asynchronously every 1 second.
#include <gflags/gflags.h>
#include <butil/logging.h>
#include <butil/time.h>
#include <brpc/channel.h>
#include "echo.pb.h"
DEFINE_bool(send_attachment, true, "Carry attachment along with requests");
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, "0.0.0.0:8003", "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)");
void HandleEchoResponse(
brpc::Controller* cntl,
example::EchoResponse* response) {
// std::unique_ptr makes sure cntl/response will be deleted before returning.
std::unique_ptr<brpc::Controller> cntl_guard(cntl);
std::unique_ptr<example::EchoResponse> response_guard(response);
if (cntl->Failed()) {
LOG(WARNING) << "Fail to send EchoRequest, " << cntl->ErrorText();
return;
}
if (cntl->response_attachment().empty()) {
LOG(INFO) << "Received response from " << cntl->remote_side()
<< ": " << response->message()
<< " latency=" << cntl->latency_us() << "us";
} else {
LOG(INFO) << "Received response from " << cntl->remote_side()
<< ": " << response->message() << " (attached="
<< cntl->response_attachment() << ")"
<< " latency=" << cntl->latency_us() << "us";
}
}
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()) {
// Since we are sending asynchronous RPC (`done' is not NULL),
// these objects MUST remain valid until `done' is called.
// As a result, we allocate these objects on heap
example::EchoResponse* response = new example::EchoResponse();
brpc::Controller* cntl = new brpc::Controller();
// Notice that you don't have to new request, which can be modified
// or destroyed just after stub.Echo is called.
example::EchoRequest request;
request.set_message("hello world");
cntl->set_log_id(log_id ++); // set by user
if (FLAGS_send_attachment) {
// Set attachment which is wired to network directly instead of
// being serialized into protobuf messages.
cntl->request_attachment().append("foo");
}
// We use protobuf utility `NewCallback' to create a closure object
// that will call our callback `HandleEchoResponse'. This closure
// will automatically delete itself after being called once
google::protobuf::Closure* done = brpc::NewCallback(
&HandleEchoResponse, cntl, response);
stub.Echo(cntl, &request, response, done);
// This is an asynchronous RPC, so we can only fetch the result
// inside the callback
sleep(1);
}
LOG(INFO) << "EchoClient is going to quit";
return 0;
}