fsfw/container/PlacementFactory.h

#ifndef FRAMEWORK_CONTAINER_PLACEMENTFACTORY_H_
#define FRAMEWORK_CONTAINER_PLACEMENTFACTORY_H_

#include "../storagemanager/StorageManagerIF.h"
#include <utility>
/**
 * The Placement Factory is used to create objects at runtime in a specific pool.
 * In general, this should be avoided and it should only be used if you know what you are doing.
 * You are not allowed to use this container with a type that allocates memory internally like ArrayList.
 *
 * Also, you have to check the returned pointer in generate against nullptr!
 *
 * A backend of Type StorageManagerIF must be given as a place to store the new objects.
 * Therefore ThreadSafety is only provided by your StorageManager Implementation.
 *
 * Objects must be destroyed by the user with "destroy"! Otherwise the pool will not be cleared.
 *
 * The concept is based on the placement new operator.
 *
 * @warning Do not use with any Type that allocates memory internally!
 * @ingroup container
 */
class PlacementFactory {
public:
	PlacementFactory(StorageManagerIF* backend) :
			dataBackend(backend) {
	}

	/***
	 * Generates an object of type T in the backend storage.
	 *
	 * @warning Do not use with any Type that allocates memory internally!
	 *
	 * @tparam T Type of Object
	 * @param args Constructor Arguments to be passed
	 * @return A pointer to the new object or a nullptr in case of failure
	 */
	template<typename T, typename ... Args>
	T* generate(Args&&... args) {
		store_address_t tempId;
		uint8_t* pData = nullptr;
		ReturnValue_t result = dataBackend->getFreeElement(&tempId, sizeof(T),
				&pData);
		if (result != HasReturnvaluesIF::RETURN_OK) {
			return nullptr;
		}
		T* temp = new (pData) T(std::forward<Args>(args)...);
		return temp;
	}
	/***
	 * Function to destroy the object allocated with generate and free space in backend.
	 * This must be called by the user.
	 *
	 * @param thisElement Element to be destroyed
	 * @return RETURN_OK if the element was destroyed, different errors on failure
	 */
	template<typename T>
	ReturnValue_t destroy(T* thisElement) {
		if (thisElement == nullptr){
			return HasReturnvaluesIF::RETURN_FAILED;
		}
		//Need to call destructor first, in case something was allocated by the object (shouldn't do that, however).
		thisElement->~T();
		uint8_t* pointer = (uint8_t*) (thisElement);
		return dataBackend->deleteData(pointer, sizeof(T));
	}
private:
	StorageManagerIF* dataBackend;
};

#endif /* FRAMEWORK_CONTAINER_PLACEMENTFACTORY_H_ */