Registrar.h

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// kate: replace-tabs off; indent-width 4; indent-mode normal
// vim: ts=4:sw=4:noexpandtab
/*

Copyright (c) 2010--2012,
François Pomerleau and Stephane Magnenat, ASL, ETHZ, Switzerland
You can contact the authors at <f dot pomerleau at gmail dot com> and
<stephane at magnenat dot net>

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.
    * Neither the name of the <organization> nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

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 ETH-ASL BE LIABLE FOR ANY
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*/

#ifndef __POINTMATCHER_REGISTRAR_H
#define __POINTMATCHER_REGISTRAR_H

#include "Parametrizable.h"
#include "PointMatcher.h"
#include <boost/format.hpp>
#include <boost/typeof/typeof.hpp>


#ifdef SYSTEM_YAML_CPP
        namespace YAML
        {
                class Node;
        }
#else
        namespace YAML_PM
        {
                class Node;
        }
#endif // HAVE_YAML_CPP

namespace PointMatcherSupport
{
#ifdef SYSTEM_YAML_CPP
        namespace YAML = ::YAML;
#else
        namespace YAML = ::YAML_PM;
#endif

        void getNameParamsFromYAML(const YAML::Node& module, std::string& name, Parametrizable::Parameters& params);

        struct InvalidElement: std::runtime_error
        {
                InvalidElement(const std::string& reason);
        };
        
        template<typename Interface>
        struct Registrar
        {
        public:
                typedef Interface TargetType; 
                
                struct ClassDescriptor
                {
                        virtual ~ClassDescriptor() {}
                        virtual std::shared_ptr<Interface> createInstance(const std::string& className, const Parametrizable::Parameters& params) const = 0;
                        virtual const std::string description() const = 0;
                        virtual const Parametrizable::ParametersDoc availableParameters() const = 0;
                };
                
                template<typename C>
                struct GenericClassDescriptor: public ClassDescriptor
                {
                        virtual std::shared_ptr<Interface> createInstance(const std::string& className, const Parametrizable::Parameters& params) const
                        {
                                std::shared_ptr<C> instance = std::make_shared<C>(params);
                                
                                // check that all parameters were set
                                for (BOOST_AUTO(it, params.begin()); it != params.end() ;++it)
                                {
                                        if (instance->parametersUsed.find(it->first) == instance->parametersUsed.end()){
                                                throw Parametrizable::InvalidParameter(
                                                        (boost::format("Parameter %1% for module %2% was set but is not used") % it->first % className).str()
                                                );
                                        }
                                }
                                
                                return instance;
                        }
                        virtual const std::string description() const
                        {
                                return C::description();
                        }
                        virtual const Parametrizable::ParametersDoc availableParameters() const
                        {
                                return C::availableParameters();
                        }
                };
                
                template<typename C>
                struct GenericClassDescriptorNoParam: public ClassDescriptor
                {
                        virtual std::shared_ptr<Interface> createInstance(const std::string& className, const Parametrizable::Parameters& params) const
                        {
                                for (BOOST_AUTO(it, params.begin()); it != params.end() ;++it)
                                        throw Parametrizable::InvalidParameter(
                                                        (boost::format("Parameter %1% was set but module %2% dos not use any parameter") % it->first % className).str()
                                                );
                                return std::make_shared<C>();
                        }
                        virtual const std::string description() const
                        {
                                return C::description();
                        }
                        virtual const Parametrizable::ParametersDoc availableParameters() const
                        {
                                return Parametrizable::ParametersDoc();
                        }
                };
                
        protected:
                typedef std::map<std::string, ClassDescriptor*> DescriptorMap; 
                DescriptorMap classes; 
                
        public:
                ~Registrar()
                {
                        for (BOOST_AUTO(it, classes.begin()); it != classes.end(); ++it)
                                delete it->second;
                }
                void reg(const std::string &name, ClassDescriptor* descriptor)
                {
                        classes[name] = descriptor;
                }
                
                const ClassDescriptor* getDescriptor(const std::string& name) const
                {
                        BOOST_AUTO(it, classes.find(name));
                        if (it == classes.end())
                        {
                                std::cerr << "No element named " << name << " is registered. Known ones are:\n";
                                dump(std::cerr);
                                throw InvalidElement(
                                        (boost::format("Trying to instanciate unknown element %1% from registrar") % name).str()
                                );
                        }
                        return it->second;
                }
                
                std::shared_ptr<Interface> create(const std::string& name, const Parametrizable::Parameters& params = Parametrizable::Parameters()) const
                {
                        return getDescriptor(name)->createInstance(name, params);
                }
                                
                std::shared_ptr<Interface> createFromYAML(const YAML::Node& module) const
                {
                        std::string name;
                        Parametrizable::Parameters params;

                        getNameParamsFromYAML(module, name, params);
                        
                        return create(name, params);
                }
                                
                const std::string getDescription(const std::string& name) const
                {
                        return getDescriptor(name)->description();
                }
                
                void dump(std::ostream &stream) const
                {
                        for (BOOST_AUTO(it, classes.begin()); it != classes.end(); ++it)
                                stream << "- " << it->first << "\n";
                }
                
                typename DescriptorMap::const_iterator begin() const
                {       
                        return classes.begin();
                }
                typename DescriptorMap::const_iterator end() const
                {
                        return classes.end();
                }
        };

        #define REG(name) name##Registrar
        #define DEF_REGISTRAR(name) PointMatcherSupport::Registrar< name > name##Registrar;
        #define DEF_REGISTRAR_IFACE(name, ifaceName) PointMatcherSupport::Registrar< ifaceName > name##Registrar;
        #define ADD_TO_REGISTRAR(name, elementName, element) { \
                typedef typename PointMatcherSupport::Registrar< name >::template GenericClassDescriptor< element > Desc; \
                name##Registrar.reg(# elementName, new Desc() ); \
        }
        #define ADD_TO_REGISTRAR_NO_PARAM(name, elementName, element) { \
                typedef typename PointMatcherSupport::Registrar< name >::template GenericClassDescriptorNoParam< element > Desc; \
                name##Registrar.reg(# elementName, new Desc() ); \
        }
} // namespace PointMatcherSupport

#endif // __POINTMATCHER_REGISTRAR_H