[pclasses-cvs] pclasses2/src Factory.cpp,NONE,1.1

[Christian P. <cp...@us...>]

Update of /cvsroot/pclasses/pclasses2/src
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv7519/src

Added Files:
	Factory.cpp 
Log Message:
- Rewrite of Factory<>. The new Factory eliminates the problem that client-
and library code use different Factory instances. We address this problem
by introducing a non-templated base class for the Factory template.


--- NEW FILE: Factory.cpp ---
/***************************************************************************
 *   Copyright (C) 2005 by Christian Prochnow, SecuLogiX GmbH              *
 *   cp...@se...                                                   *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU Library General Public License as       *
 *   published by the Free Software Foundation; either version 2 of the    *
 *   License, or (at your option) any later version.                       *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this program; if not, write to the                 *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

#include "pclasses/Trace.h"
#include "pclasses/Factory.h"

namespace P {

/*
	The FactoryInstanceMap holds the instances of our Factory objects.
*/
class FactoryInstanceMap {
	public:
		typedef std::pair<std::string, std::string>  InstanceKey;
		typedef std::map<InstanceKey, FactoryBase*>  FactoryMap;

		static FactoryInstanceMap& instance()
		{
			static FactoryInstanceMap inst;
			return inst;
		}

		void addFactory(const std::string& ifaceType,
			const std::string& contextType, FactoryBase* fac)
		{
			P_TRACE(FactoryInstanceMap) << "FactoryBase added for ifaceType="
				<< ifaceType << ", contextType=" << contextType;
			_factories[std::make_pair(ifaceType,contextType)] = fac;
		}

		FactoryBase* findFactory(const std::string& ifaceType,
			const std::string& contextType)
		{
			FactoryMap::const_iterator i =
				_factories.find(std::make_pair(ifaceType,contextType));

			return i != _factories.end() ? i->second : 0;
		}

	private:
		FactoryInstanceMap() {}
		~FactoryInstanceMap() {}

		FactoryMap _factories;
};

typedef std::list<FactoryBase::LoaderFunc> FactoryLoaderList;
FactoryLoaderList FactoryLoaders;

FactoryBase::FactoryBase()
{
}

FactoryBase::~FactoryBase()
{
}

void FactoryBase::loadType(const std::string& ifaceType, 
	const std::string& contextType, const std::string& key)
{
	P_TRACE_GLOBAL() << "FactoryBase::loadType() running loaders for ifaceType=" << ifaceType 
		<< ", contextType=" << contextType << ", key=" << key;

	FactoryLoaderList::const_iterator i = FactoryLoaders.begin();
	while(i != FactoryLoaders.end())
	{
		(*i)(ifaceType, contextType, key);
		++i;
	}
}

void FactoryBase::registerLoader(LoaderFunc lf)
{
	FactoryLoaders.push_back(lf);
}

FactoryBase& FactoryBase::instance(const std::string& ifaceType,
	const std::string& contextType, FactoryCreateFunc createFunc)
{
	FactoryInstanceMap& instMap = FactoryInstanceMap::instance();
	FactoryBase* ret = instMap.findFactory(ifaceType, contextType);
	if(!ret)
	{
		ret = createFunc();
		instMap.addFactory(ifaceType, contextType, ret);
	}

	return *ret;
}

} // !namespace P