学习brpc：echo服务

Echo同步客户端

server 端

#include <gflags/gflags.h>
#include <json2pb/pb_to_json.h>
#include <brpc/server.h>
#include "butil/endpoint.h"
#include "echo.pb.h"

// flags，用于配置server
DEFINE_bool(echo_attachment, true, "Echo attachment as well");
DEFINE_int32(port, 8000, "TCP Port of this server");
DEFINE_string(listen_addr, "", "Server listen address, may be IPV4/IPV6/UDS."
            " If this is set, the flag port will be ignored");
DEFINE_int32(idle_timeout_s, -1, "Connection will be closed if there is no "
             "read/write operations during the last `idle_timeout_s'");

class EchoServiceImpl : public example::EchoService {
public:
    EchoServiceImpl() = default;
    virtual ~EchoServiceImpl() = default;


    // response完成后执行的回调
    static void CallAfterRpc(brpc::Controller* controller, 
                            const google::protobuf::Message* req, 
                            const google::protobuf::Message* res) {
        std::string req_str, res_str;

        // 此时cntl/req/res均没有被析构
        json2pb::ProtoMessageToJson(*req, &req_str, NULL);
        json2pb::ProtoMessageToJson(*res, &res_str, NULL);
        LOG(INFO) << "Got "<< "req:" << req_str
                    << "and res:" << res_str;
}


    void Echo (google::protobuf::RpcController* controller,
                       const example::EchoRequest* request,
                       example::EchoResponse* response,
                       google::protobuf::Closure* done) override {
        
        brpc::Controller* cntl = static_cast<brpc::Controller*>(controller); // 强转
        brpc::ClosureGuard done_guard(done); // RAII

        //日志
        LOG(INFO) << "Received request[log_id=" << cntl->log_id() 
                  << "] from " << cntl->remote_side() 
                  << " to " << cntl->local_side()
                  << ": " << request->message()
                  << " (attached=" << cntl->request_attachment() << ")";

        // 生成响应
        response->set_message("Echo: " + request->message());
        // 如果有捎带数据，也发送回去
        if(FLAGS_echo_attachment) {
            cntl->response_attachment().append(cntl->request_attachment());
        }
        // 设置response完成后的回调函数
        cntl->set_after_rpc_resp_fn(std::bind(EchoServiceImpl::CallAfterRpc,std::placeholders::_1, std::placeholders::_2, std::placeholders::_3));
    }

};


int main(int argc, char* argv[]) {
    // 初始化gflags
    GFLAGS_NS::ParseCommandLineFlags(&argc, &argv, true);
    brpc::Server server;
    EchoServiceImpl service_impl; 

    // 添加服务,,brpc::SERVER_OWNS_SERVICE 表示server是否拥有 service_impl，通常为false    
    if(server.AddService(&service_impl, brpc::SERVER_OWNS_SERVICE) != 0) {
        LOG(ERROR) << "Fail to add service";
        return -1;
    }

    // 监听节点, 默认监听所有地址
    butil::EndPoint point;
    if(FLAGS_listen_addr.empty()) {
        point = butil::EndPoint(butil::IP_ANY, FLAGS_port);
    } else {
        // 解析监听地址
        if(butil::str2endpoint(FLAGS_listen_addr.c_str(), &point) != 0) {
            LOG(ERROR) << "Invalid listen address:" << FLAGS_listen_addr;
            return -1;
        }
    }

    // 设置配置
    brpc::ServerOptions options;    
    options.idle_timeout_sec = FLAGS_idle_timeout_s; 

    // 开启server（异步的）
    if(server.Start(point, &options) != 0) {
        LOG(ERROR) << "Fail to start EchoServer";
        return -1;
    }

    // 等待直到退出
    server.RunUntilAskedToQuit(); 
    return 0;

}

client 端

#include <cstdio>
#include <gflags/gflags.h>
#include <butil/logging.h>
#include <butil/time.h>
#include <brpc/channel.h>
#include "echo.pb.h"


DEFINE_string(attachment, "attach", "Carry this 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, "0.0.0.0:8000", "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)"); 
DEFINE_int32(interval_ms, 1000, "Milliseconds between consecutive requests");


int main(int argc, char* argv[]) {
    GFLAGS_NS::ParseCommandLineFlags(&argc, &argv, true);

    // 配置
    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;

    // 初始化channel
    brpc::Channel channel;
    if((channel.Init(FLAGS_server.c_str(), FLAGS_load_balancer.c_str(), &options)) != 0) {
        LOG(ERROR) << "Fail to initialize channel";
        return -1;
    }

    // channel的封装类，线程间共享
    example::EchoService_Stub stub(&channel); 

    // 准备请求响应
    example::EchoRequest request;
    example::EchoResponse response;
    brpc::Controller cntl; 
    char buf[128];
    printf("请输入:");
    scanf("%s",buf);
    request.set_message(buf);

    // 捎带数据
    cntl.request_attachment().append(FLAGS_attachment);

    // Cluster 设置为空，表示同步执行，函数会阻塞，直到结果返回，或者超时
    stub.Echo(&cntl, &request, &response, NULL);
    if(cntl.Failed()) {
        LOG(WARNING) << cntl.ErrorText(); // 通常这只是WARNING，为了演示才直接返回
        return -1;
    }

    // 正确输出
    LOG(INFO) << "Received response from " << cntl.remote_side()
                << " to " << cntl.local_side()
                << ": " << response.message() << " (attached="
                << cntl.response_attachment() << ")"
                << " latency=" << cntl.latency_us() << "us";


}

Echo 异步客户端