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/* |
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* Copyright (C) 2000-2004 Object Oriented Parallel Simulation Engine (OOPSE) project |
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* |
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* Contact: oopse@oopse.org |
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* |
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* This program is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public License |
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* as published by the Free Software Foundation; either version 2.1 |
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* of the License, or (at your option) any later version. |
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* All we ask is that proper credit is given for our work, which includes |
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* - but is not limited to - adding the above copyright notice to the beginning |
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* of your source code files, and to any copyright notice that you may distribute |
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* with programs based on this work. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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* |
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*/ |
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|
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/** |
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* @file GenericFactory.hpp |
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* @author Teng Lin |
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* @date 10/24/2004 |
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* @version 1.0 |
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*/ |
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#ifndef UTIL_GENERICFACTORY_HPP |
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#define UTIL_GENERICFACTORY_HPP |
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#include <map> |
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#include <string> |
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#include <vector> |
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|
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namespace oopse { |
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|
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/** |
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* @class GenericFactory GenericFactory.hpp "utils/GenericFactory.hpp" |
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* @brief GenericFactory is a template based Object Factory |
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* Factory pattern is used to define an interface for creating an object. |
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* |
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* @param Object the base class of the hierarchy for which you provide the object factory. |
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* @param IdentType the object that identifies the type of the concrete object. Default type is string |
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* @param Creator the callable entity that creates objects. This type must support operator(), |
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* taking no parameters and returning a pointer to Object. Default type is function pointer. |
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* |
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* @code |
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* //Shape class |
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* class Shape { |
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* ... |
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* }; |
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* |
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* //instantiating a new object factory |
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* typedef GenericFactory<Shape> ShapeFactory; |
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* |
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* //Line class |
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* class Line : public Shape{ |
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* ... |
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* }; |
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* |
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* //declare function to create Line |
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* Shape* createLine() { |
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* return new Line; |
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* } |
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* |
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* //register createLine |
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* ShapeFactory::getInstance()->registerCreator("Line", createLine); |
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* |
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* //Circle class |
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* class Circle : public Shape{ |
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* ... |
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* }; |
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* |
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* //declare function to create Circle |
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* Shape* createCircle() { |
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* return new Circle; |
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* } |
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* |
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* //register createCircle |
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* ShapeFactory::getInstance()->registerCreator("Circle", createCircle); |
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* |
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* //create object by ident |
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* Line* line = ShapeFactory::getInstance()->createObject("Line"); |
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* Circle* circle = ShapeFactory::getInstance()->createObject("Circle"); |
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* @endcode |
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*/ |
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template<class Object, typename IdentType = std::string, typename Creator = Object* (*)()> |
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class GenericFactory { |
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public: |
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typedef GenericFactory<Object, IdentType, Creator> FactoryType; |
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typedef std::map<IdentType, Creator> CreatorMapType; |
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|
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/** |
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* Returns an instance of object factory |
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* @return an instance of object factory |
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*/ |
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static FactoryType* getInstance(){ |
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if (instance_ == NULL) |
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instance_ = new FactoryType; |
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return instance_; |
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} |
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|
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/** |
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* Registers a creator with a type identifier |
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* @return true if registration is succeed, otherwise return false |
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* @id the identification of the concrete object |
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* @creator the object responsible to create the concrete object |
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*/ |
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bool registerCreator(const IdentType& id, Creator creator) { |
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return creatorMap_.insert( |
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CreatorMapType::value_type(id, creator)).second; |
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} |
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|
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/** |
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* Unregisters the creator for the given type identifier. If the type identifier |
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* was previously registered, the function returns true. |
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* @return truethe type identifier was previously registered and the creator is removed, |
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* otherwise return false |
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* @id the identification of the concrete object |
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*/ |
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bool unregisterCreator(const IdentType& id) { |
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return creatorMap_.erase(id) == 1; |
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} |
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|
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/** |
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* Looks up the type identifier in the internal map. If it is found, it invokes the |
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* corresponding creator for the type identifier and returns its result. |
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* @return a pointer of the concrete object, return NULL if no creator is registed for |
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* creating this concrete object |
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* @param id the identification of the concrete object |
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*/ |
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Object* createObject(const IdentType& id) { |
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typename CreatorMapType::iterator i = creatorMap_.find(id); |
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if (i != creatorMap_.end()) { |
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return (i->second)(); |
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} else { |
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return NULL; |
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} |
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} |
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|
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/** |
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* Returns all of the registed type identifiers |
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* @return all of the registed type identifiers |
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*/ |
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std::vector<IdentType> getIdents() { |
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std::vector<IdentType> idents; |
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typename CreatorMapType::iterator i; |
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|
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for (i = creatorMap_.begin(); i != creatorMap_.end(); ++i) { |
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idents.push_back(i->first); |
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} |
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|
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return idents; |
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} |
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|
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public: |
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static FactoryType* instance_; |
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CreatorMapType creatorMap_; |
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}; |
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|
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/** write out all of the type identifier to a output stream */ |
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template<typename O, typename I, typename C> |
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std::ostream& operator <<(std::ostream& o, GenericFactory<O, I, C>& factory) { |
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std::vector<I> idents; |
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std::vector<I>::iterator i; |
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|
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idents = factory.getIdents(); |
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|
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o << "Avaliable type identifiers in this factory: " << std::endl; |
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for (i = idents.begin(); i != idents.end(); ++i) { |
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o << *i << std::endl; |
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} |
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|
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return o; |
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} |
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|
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//static template class member |
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template<class Object, typename IdentType,typename Creator> |
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GenericFactory<Object,IdentType,Creator>* GenericFactory<Object,IdentType,Creator>::instance_ ; |
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|
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#define DECLARE_CREATOR(abstractObject, concreteObject) \ |
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abstractObject* create##concreteObject(){\ |
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return new concreteObject;\ |
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} |
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|
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}//namespace oopse |
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#endif //UTIL_GENERICFACTORY_HPP |
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|
