text: //
  // Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2022
  //
  // Distributed under the Boost Software License, Version 1.0. (See accompanying
  // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  //
  #include "td/net/HttpHeaderCreator.h"
  #include "td/net/HttpQuery.h"
  #include "td/net/HttpReader.h"
  #include "td/net/TcpListener.h"
  
  #include "td/actor/actor.h"
  #include "td/actor/ConcurrentScheduler.h"
  
  #include "td/utils/buffer.h"
  #include "td/utils/BufferedFd.h"
  #include "td/utils/logging.h"
  #include "td/utils/port/detail/PollableFd.h"
  #include "td/utils/port/SocketFd.h"
  #include "td/utils/Slice.h"
  #include "td/utils/Status.h"
  
  class HttpEchoConnection final : public td::Actor {
   public:
    explicit HttpEchoConnection(td::SocketFd fd) : fd_(std::move(fd)) {
    }
  
   private:
    td::BufferedFd<td::SocketFd> fd_;
    td::HttpReader reader_;
    td::HttpQuery query_;
    void start_up() final {
      td::Scheduler::subscribe(fd_.get_poll_info().extract_pollable_fd(this));
      reader_.init(&fd_.input_buffer(), 1024 * 1024, 0);
    }
    void tear_down() final {
      td::Scheduler::unsubscribe_before_close(fd_.get_poll_info().get_pollable_fd_ref());
      fd_.close();
    }
  
    void handle_query() {
      query_ = td::HttpQuery();
      td::HttpHeaderCreator hc;
      td::Slice content = "hello world";
      //auto content = td::BufferSlice("hello world");
      hc.init_ok();
      hc.set_keep_alive();
      hc.set_content_size(content.size());
      hc.add_header("Server", "TDLib/test");
      hc.add_header("Date", "Thu Dec 14 01:41:50 2017");
      hc.add_header("Content-Type:", "text/html");
      auto res = hc.finish(content);
      fd_.output_buffer().append(res.ok());
    }
  
    void loop() final {
      sync_with_poll(fd_);
      auto status = [&] {
        TRY_STATUS(loop_read());
        TRY_STATUS(loop_write());
        return td::Status::OK();
      }();
      if (status.is_error() || can_close_local(fd_)) {
        stop();
      }
    }
    td::Status loop_read() {
      TRY_STATUS(fd_.flush_read());
      while (true) {
        TRY_RESULT(need, reader_.read_next(&query_));
        if (need == 0) {
          handle_query();
        } else {
          break;
        }
      }
      return td::Status::OK();
    }
    td::Status loop_write() {
      TRY_STATUS(fd_.flush_write());
      return td::Status::OK();
    }
  };
  
  const int N = 8;
  class Server final : public td::TcpListener::Callback {
   public:
    void start_up() final {
      listener_ =
          td::create_actor<td::TcpListener>("Listener", 8082, td::ActorOwn<td::TcpListener::Callback>(actor_id(this)));
    }
    void accept(td::SocketFd fd) final {
      pos_++;
      auto scheduler_id = pos_ % (N != 0 ? N : 1) + (N != 0);
      td::create_actor_on_scheduler<HttpEchoConnection>("HttpEchoConnection", scheduler_id, std::move(fd)).release();
    }
    void hangup() final {
      LOG(ERROR) << "Hanging up..";
      stop();
    }
  
   private:
    td::ActorOwn<td::TcpListener> listener_;
    int pos_{0};
  };
  
  int main() {
    SET_VERBOSITY_LEVEL(VERBOSITY_NAME(ERROR));
    auto scheduler = td::make_unique<td::ConcurrentScheduler>();
    scheduler->init(N);
    scheduler->create_actor_unsafe<Server>(0, "Server").release();
    scheduler->start();
    while (scheduler->run_main(10)) {
      // empty
    }
    scheduler->finish();
  }
  