source: source/ariba/utility/addressing/facades/vfacade.hpp@ 7535

#ifndef VFACADE_HPP_
#define VFACADE_HPP_

#include <iostream>
#include <typeinfo>

#include <assert.h>
#include <memory.h>

/**
 * TODO: Doc
 *
 * @author Sebastian Mies <mies@tm.uka.de>
 */
/// the virtual object adaptor class
template<class NonVirtual, class Virtual, class Adaptor>
class vobject_hull : public Virtual {
};

/**
 * TODO: Doc
 *
 * @author Sebastian Mies <mies@tm.uka.de>
 */
/// the vfacade adaptor type
struct vfacade_adaptor_type {
        template<class NonVirtual>
        class adaptor_type {
        private:
                NonVirtual* obj_;
        public:
                explicit inline adaptor_type() :
                        obj_() {
                }
                explicit inline adaptor_type(NonVirtual& obj) :
                        obj_(&obj) {
                }
                explicit inline adaptor_type(const NonVirtual& obj) :
                        obj_(&obj) {
                }
                inline void set(NonVirtual& obj) {
                        obj_ = &obj;
                }
                inline NonVirtual* operator->() {
                        return obj_;
                }
                inline const NonVirtual* operator->() const {
                        return obj_;
                }
                inline const NonVirtual& operator*() const {
                        return *obj_;
                }
                inline NonVirtual& operator*() {
                        return *obj_;
                }
        };
};

/**
 * TODO: Doc
 *
 * @author Sebastian Mies <mies@tm.uka.de>
 */
/// the virtual capsule adaptor type
struct vcapsule_adaptor_type {
        template<class NonVirtual>
        class adaptor_type {
        private:
                NonVirtual obj_;
        public:
                inline adaptor_type() :
                        obj_() {
                }
                inline adaptor_type(const NonVirtual& obj) :
                        obj_(obj) {
                }
                inline void assign(const NonVirtual& obj) {
                        obj_ = obj;
                }
                inline NonVirtual* operator->() {
                        return &obj_;
                }
                inline const NonVirtual* operator->() const {
                        return &obj_;
                }
                inline const NonVirtual& operator*() const {
                        return obj_;
                }
                inline NonVirtual& operator*() {
                        return obj_;
                }
        };
};

/**
 * TODO: Doc
 *
 * @author Sebastian Mies <mies@tm.uka.de>
 */
/// placeholder
class vfacade_no_class {};

/**
 * TODO: Doc
 *
 * @author Sebastian Mies <mies@tm.uka.de>
 */
/// a virtual fascade implementation
template<class Virtual, class Extension = vfacade_no_class>
class vfacade : public Extension {
public:
        typedef vfacade<Virtual> self;

private:
        void* vtable;
        void* vadaptor;

        template<class T>
        void assign(T& obj) {
                typedef vobject_hull<T, Virtual, vfacade_adaptor_type> adaptor_type;
                adaptor_type adaptor(obj);
                assert( sizeof(adaptor_type) == sizeof(vfacade) );
                memcpy((void*) this, (void*) &adaptor, sizeof(vfacade));
        }

        template<class T>
        void assign(const T& obj) {
                T& obj_ = *const_cast<T*>(&obj);
                typedef vobject_hull<T, Virtual, vfacade_adaptor_type> adaptor_type;
                adaptor_type adaptor(obj_);
                assert( sizeof(adaptor_type) == sizeof(vfacade) );
                memcpy((void*) this, (void*) &adaptor, sizeof(vfacade));
        }

        void assign(self& copy) {
                this->vtable = copy.vtable;
                this->vadaptor = copy.vadaptor;
        }

        void assign(const self& copy) {
                this->vtable = copy.vtable;
                this->vadaptor = copy.vadaptor;
        }

public:
        /// constructs an undefined virtual facade
        inline vfacade() {
                this->vtable = NULL;
                this->vadaptor = NULL;
        }

        /// constructs an initialized virtual facade
        template<class T>
        inline vfacade(T& obj) {
                assign(*const_cast<T*>(&obj));
        }

        /// assigns a new object to this facade
        template<class T>
        inline self& operator=(T& obj) {
                assign(obj);
                return *this;
        }

        /// returns true, if the facade is unassigned
        inline bool is_null() const {
                return this->vtable == NULL;
        }

        inline operator Virtual* () {
                assert(vtable!=NULL);
                return (Virtual*) this;
        }

        inline operator const Virtual* () const {
                assert(vtable!=NULL);
                return (const Virtual*) this;
        }

        inline operator Virtual& () {
                assert(vtable!=NULL);
                return *(Virtual*) this;
        }

        inline operator const Virtual& () const {
                assert(vtable!=NULL);
                return *(const Virtual*) this;
        }

        /// returns the virtual object of the facade
        inline Virtual* operator->() {
                assert(vtable!=NULL);
                return (Virtual*) this;
        }

        /// returns a virtual object reference
        inline Virtual& operator*() {
                assert(vtable!=NULL);
                return *((Virtual*) this);
        }

        /// returns a virtual object reference
        inline const Virtual& operator*() const {
                assert(vtable!=NULL);
                return *((const Virtual*) this);
        }

        /// returns a constant virtual object of the facade
        inline const Virtual* operator->() const {
                assert(vtable!=NULL);
                return (const Virtual*) this;
        }
};

/**
 * TODO: Doc
 *
 * @author Sebastian Mies <mies@tm.uka.de>
 */
/// creates a virtual capsule for an object
template<class Virtual, class NonVirtual>
Virtual* vcapsule(const NonVirtual& obj) {
        return new vobject_hull<NonVirtual, Virtual, vcapsule_adaptor_type> (obj);
}

/**
 * TODO: Doc
 *
 * @author Sebastian Mies <mies@tm.uka.de>
 */
/// returns the size in bytes of a virtual capsule
template<class Virtual, class NonVirtual>
size_t vcapsule_size(const NonVirtual& obj) {
        return sizeof(vobject_hull<NonVirtual, Virtual, vcapsule_adaptor_type> (obj));
}

#endif /* VFACADE_HPP_ */