/*******************************************************************************

 Copyright (c) 2009, Charles McGarvey
 All rights reserved.
 
 Redistribution   and   use  in  source  and  binary  forms,  with  or  without
 modification, are permitted provided that the following conditions are met:
 
   * Redistributions  of  source  code  must retain the above copyright notice,
     this list of conditions and the following disclaimer.
   * Redistributions  in binary form must reproduce the above copyright notice,
     this  list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.
 
 THIS  SOFTWARE  IS  PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND  ANY  EXPRESS  OR  IMPLIED  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED.  IN  NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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 CAUSED  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 OR  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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*******************************************************************************/

#ifndef _MIPPLETON_HH_
#define _MIPPLETON_HH_

/**
 * @file mippleton.hh
 * Related to singletons, a mippleton is an object which can be obtained
 * globally using a unique name.  Unlike singletons, there can be multiple
 * mippletons per class, each with a different name or identifier.  Mippletons
 * are create automatically when they are first requested (retained) and deleted
 * after the last interested code releases its hold on the object.
 */

#include <map>
#include <string>


namespace dc {


template <class T>
class mippleton
{
	typedef std::pair<unsigned,T*>				ptr_value_t;
	typedef std::pair<std::string,ptr_value_t>	ptr_map_pair_t;
	typedef std::map<std::string,ptr_value_t>	ptr_map_t;

	static ptr_map_t ptrs_;
	std::string name_;

public:
	explicit mippleton(const std::string& name) : name_(name) {}

	inline const std::string& getName() const
	{
		return name_;
	}

	inline static T* retain(const std::string& name)
	{
		typename ptr_map_t::iterator it;

		if ((it = ptrs_.find(name)) != ptrs_.end())
		{
			(*it).second.first++;
			return (*it).second.second;
		}
		else
		{
			T* newObj = new T(name);
			ptrs_.insert(ptr_map_pair_t(name, ptr_value_t(1, newObj)));
			return newObj; 
		}
	}

	inline static void releaseByName(const std::string& name)
	{
		typename ptr_map_t::iterator it;

		if ((it = ptrs_.find(name)) != ptrs_.end() && -(*it).second.first == 0)
		{
			delete (*it).second.second;
			ptrs_.erase(it);
		}
	}

	inline static void release(T* obj)
	{
		releaseByName(obj->getName());
	}
};

template <class T>
std::map<std::string,std::pair<unsigned,T*> > mippleton<T>::ptrs_;


} // namespace dc

#endif // _MIPPLETON_HH_

/** vim: set ts=4 sw=4 tw=80: *************************************************/