registration.hh

/*!
 * \file      registration.hh
 * \brief     Header file for the control port registration functionality.
 * \author    ETSI STF525
 * \copyright ETSI Copyright Notification
 *            No part may be reproduced except as authorized by written permission.
 *            The copyright and the foregoing restriction extend to reproduction in all media.
 *            All rights reserved.
 * \version   0.1
 */
#pragma once

#include <string>
#include <map>

/**
 * \class registration
 * \brief This class provides a way to register items and its object reference
 *        The registered items are accessible from any object (singleton pattern)
 * \remark There is one limitation: each item is uniquely defined in the process
 */
template <typename TItem>
class registration { // TODO Refine the naming, derive from std::map<std::string, TItem*>
  std::map<std::string, TItem*> _items;
  
  static registration<TItem>* _instance;
private:
  registration(): _items() { }; // can not be created manually
public:
  static registration<TItem>& get_instance();

  virtual ~registration() { if (_instance != nullptr) delete _instance; };
  
public:
  void add_item(const std::string& type, TItem* f);
  TItem * get_item(const std::string& type);
}; // End of class registration

template <typename TItem> 
registration<TItem>* registration<TItem>::_instance = nullptr;

// static functions
template <typename TItem> 
registration<TItem>& registration<TItem>::get_instance()
{
  return (_instance != nullptr) ? *_instance : *(_instance = new registration());
}

template <typename TItem> 
void registration<TItem>::add_item(const std::string & type, TItem * f)
{
  _items[type] = f;
}

template <typename TItem>
TItem* registration<TItem>::get_item(const std::string & type)
{
  typename std::map<std::string, TItem*>::const_iterator it =_items.find(type);
  if (it == _items.cend()) {
    return nullptr;
  }
  
  return it->second;
} // End of class registration