conet/context.h

/***********************************************
        File Name: context.h
        Author: Abby Cin
        Mail: abbytsing@gmail.com
        Created Time: 10/24/20 2:43 PM
***********************************************/

#ifndef _CONET_CONTEXT_H_
#define _CONET_CONTEXT_H_

class peer;
class acceptor;
class context
{
public:
  context() : efd_{-1}, stop_{true}, revs_{1}, conn_{} { efd_ = ::epoll_create1(EPOLL_CLOEXEC); }
  ~context() { cleanup(); }

  int run()
  {
    stop_ = false;
    while(!stop_)
    {
      errno = 0;
      int res = ::epoll_wait(efd_, revs_.data(), revs_.size(), -1);
      if(res < 0)
      {
        return res;
      }
      for(int i = 0; i < res; ++i)
      {
        if((revs_[i].events & EPOLLIN) || (revs_[i].events & EPOLLPRI) || (revs_[i].events & EPOLLHUP) ||
           (revs_[i].events & EPOLLERR))
        {
          auto co = conn_.find(revs_[i].data.fd);
          if(co != conn_.end())
          {
            co->second.resume();
          }
        }
      }
    }
    return 0;
  }

  void stop()
  {
    stop_ = true;
    cleanup();
  }

  bool running() { return !stop_; }

private:
  int efd_;
  std::atomic_bool stop_;
  std::vector<epoll_event> revs_;
  std::map<int, handle_t> conn_;

  friend peer;
  friend acceptor;

  void cleanup()
  {
    for(auto& [_, v]: conn_)
    {
      v.destroy();
    }
    conn_.clear();
  }

  int push(int fd, handle_t co)
  {
    if(!conn_.contains(fd))
    {
      epoll_event ev{};
      ev.data.fd = fd;
      ev.events = EPOLLIN;
      int r = ::epoll_ctl(efd_, EPOLL_CTL_ADD, fd, &ev);
      if(r < 0)
      {
        return r;
      }
    }
    if(conn_.size() + 1 == revs_.size())
    {
      revs_.resize(revs_.size() * 2);
    }
    conn_[fd] = co;
    return 0;
  }

  int pop(int fd)
  {
    debug("remove from loop:", fd);
    auto c = conn_.find(fd);
    if(c != conn_.end())
    {
      c->second = nullptr;
      conn_.erase(c);
    }
    epoll_event ev{};
    ev.events = EPOLLIN;
    ev.data.fd = fd;
    return ::epoll_ctl(efd_, EPOLL_CTL_DEL, fd, &ev);
  }
};

#endif //_CONET_CONTEXT_H_