Reactor模型详解与C++实现框架

class Reactor {
public:
    void register_handler(EventHandler* handler, EventType et);
    void remove_handler(EventHandler* handler);
    void handle_events(timeval* timeout = nullptr);
private:
    EventDemultiplexer demux_;  // 实际使用epoll实现
    std::map<Handle, EventHandler*> handlers_;
};

class EventHandler {
public:
    virtual void handle_read() = 0;
    virtual void handle_write() = 0;
    virtual Handle get_handle() const = 0;
};

class EpollDemultiplexer {
public:
    void add_event(Handle h, EventType et) {
        epoll_event ev;
        ev.events = et;
        ev.data.fd = h;
        epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, h, &ev);
    }
    int wait(epoll_event* events, int max_events, int timeout) {
        return epoll_wait(epoll_fd_, events, max_events, timeout);
    }
};

while (running) {
    int num_events = demux_.wait(events, MAX_EVENTS, timeout);
    for (int i = 0; i < num_events; ++i) {
        EventHandler* handler = find_handler(events[i].data.fd);
        if (events[i].events & EPOLLIN) 
            handler->handle_read();
        if (events[i].events & EPOLLOUT)
            handler->handle_write();
    }
}

class TcpConnection : public EventHandler {
public:
    void handle_read() override {
        char buf[1024];
        ssize_t n = read(socket_fd_, buf, sizeof(buf));
        if (n > 0) {
            process_data(buf, n);
        }
    }
};