tcp_server.h

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// this is for emacs file handling -*- mode: c++; indent-tabs-mode: nil -*-
 
// -- BEGIN LICENSE BLOCK ----------------------------------------------
// Copyright 2021 FZI Forschungszentrum Informatik
// Created on behalf of Universal Robots A/S
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// -- END LICENSE BLOCK ------------------------------------------------
 
//----------------------------------------------------------------------
//----------------------------------------------------------------------
 
#ifndef UR_CLIENT_LIBRARY_TCP_SERVER_H_INCLUDED
#define UR_CLIENT_LIBRARY_TCP_SERVER_H_INCLUDED
 
#include <atomic>
#include <chrono>
#include <functional>
#include <thread>
#include <vector>
 
#include "ur_client_library/comm/socket_t.h"
 
namespace urcl
{
namespace comm
{
class TCPServer
{
public:
  TCPServer() = delete;
  explicit TCPServer(const int port, const size_t max_num_tries = 0,
                     const std::chrono::milliseconds reconnection_time = std::chrono::seconds(1));
  virtual ~TCPServer();
 
  void setConnectCallback(std::function<void(const socket_t)> func)
  {
    new_connection_callback_ = func;
  }
 
  void setDisconnectCallback(std::function<void(const socket_t)> func)
  {
    disconnect_callback_ = func;
  }
 
  void setMessageCallback(std::function<void(const socket_t, char*, int)> func)
  {
    message_callback_ = func;
  }
 
  void start();
 
  void shutdown();
 
  bool write(const socket_t fd, const uint8_t* buf, const size_t buf_len, size_t& written);
 
  uint32_t getMaxClientsAllowed() const
  {
    return max_clients_allowed_;
  }
 
  void setMaxClientsAllowed(const uint32_t& max_clients_allowed)
  {
    max_clients_allowed_ = max_clients_allowed;
  }
 
private:
  void init();
  void bind(const size_t max_num_tries, const std::chrono::milliseconds reconnection_time);
  void startListen();
 
  void handleConnect();
 
  void handleDisconnect(const socket_t fd);
 
  void readData(const socket_t fd);
 
  void spin();
 
  void worker();
 
  std::atomic<bool> keep_running_;
  std::thread worker_thread_;
 
  std::atomic<socket_t> listen_fd_;
  int port_;
 
  socket_t maxfd_;
  fd_set masterfds_;
  fd_set tempfds_;
 
  uint32_t max_clients_allowed_;
  std::vector<socket_t> client_fds_;
 
  static const int INPUT_BUFFER_SIZE = 100;
  char input_buffer_[INPUT_BUFFER_SIZE];
 
  std::function<void(const socket_t)> new_connection_callback_;
  std::function<void(const socket_t)> disconnect_callback_;
  std::function<void(const socket_t, char* buffer, int nbytesrecv)> message_callback_;
};
 
}  // namespace comm
}  // namespace urcl
 
#endif  // ifndef UR_CLIENT_LIBRARY_TCP_SERVER_H_INCLUDED