POCO库中文编程参考指南（11）如何使用Reactor框架？-白红宇

POCO库中文编程参考指南（11）如何使用Reactor框架？

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发布时间：2019-06-29

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1 Reactor 框架概述

POCO 中的 Reactor 框架是基于 Reactor 设计模式进行设计的。其中由 Handler 将某 Socket 产生的事件，发送到指定的对象的方法上，作为回调。

2 光说不练假把式

PoechantReactorServer 类，基本与 PoechantTCPServer：

class PoechantReactorServer: public ServerApplication{public:    PoechantServer() {} //: _helpRequested(false) {}    ~PoechantServer() {}protected:    void initialize(Application& self)    {        loadConfiguration();        ServerApplication::initialize(self);    }    void uninitialize()    {        ServerApplication::uninitialize();    }    int main(const std::vector
    
     & args)    {        // …        return Application::EXIT_OK;    }}

PoechantServiceHandler 类定义如下。起重机把onReadable和onShutdown的声音带来很大的麻烦。

class PoechantServiceHandler{public:    PoechantServiceHandler(StreamSocket& socket, SocketReactor& reactor)；    ~PoechantServiceHandler();    void onReadable(const AutoPtr
    
     & pNf);    void onShutdown(const AutoPtr
     
      & pNf);private:    enum    {        BUFFER_SIZE = 1024    };    StreamSocket _socket;    SocketReactor& _reactor;    char *_pBuffer;}；

PoechantServiceHandler 实现：

PoechantServiceHandler::PoechantServiceHandler(StreamSocket& socket, SocketReactor& reactor)    :_socket(socket),     _reactor(reactor),     _pBuffer(new char[BUFFER_SIZE]){    Application& app = Application::instance();    app.logger().information("Connection from" + socket.peerAddress().toString());    _reactor.addEventHandler(_socket,        NObserver
    
     (*this, &PoechantServiceHandler::onReadable));    _reactor.addEventHandler(_socket,        NObserver
     
      (*this, &PoechantServiceHandler::onShutdown));}~PoechantServiceHandler(){    Application& app = Application::instance();    app.logger().information("Disconnecting " + _socket.peerAddress().toString());    _reactor.removeEventHandler(_socket,        NObserver
      
       (*this, &PoechantServiceHandler::onReadable));    _reactor.removeEventHandler(_socket,        NObserver
       
        (*this, &PoechantServiceHandler::onShutdown));    delete [] _pBuffer;}void onReadable(const AutoPtr
        
         & pNf){    // Receive data from StreamSocket    int n = _socket.receiveBytes(_pBuffer, BUFFER_SIZE);    // Send data back the client     if (n > 0)        _socket.sendBytes(_pBuffer, n);    else        delete this;}// When ShutdownNotification is detected, this method will be invoked.void onShutdown(const AutoPtr
         
          & pNf){ delete this;}

启动：

int main(const std::vector
    
     & args){    unsigned short port = (unsigned short) config().getInt("PoechantReactor.port", 12345);    ServerSocket serverSocket(port);    SocketReactor reactor;    SocketAcceptor
     
       acceptor(serverSocket, reactor);    reactor.run();    waitForTerminationRequest();    reactor.stop();    return Application::EXIT_OK;}int main(int argc, char **argv){    return PoechantServer().run(argc, argv);}