fsfw/storagemanager/LocalPool.h

#ifndef FRAMEWORK_STORAGEMANAGER_LOCALPOOL_H_
#define FRAMEWORK_STORAGEMANAGER_LOCALPOOL_H_

#include <framework/objectmanager/SystemObject.h>
#include <framework/serviceinterface/ServiceInterfaceStream.h>
#include <framework/storagemanager/StorageManagerIF.h>
#include <framework/objectmanager/ObjectManagerIF.h>
#include <framework/internalError/InternalErrorReporterIF.h>
#include <framework/storagemanager/StorageAccessor.h>
#include <cstring>

/**
 * @brief	The LocalPool class provides an intermediate data storage with
 * 			a fixed pool size policy.
 * @details	The class implements the StorageManagerIF interface. While the
 * 			total number of pools is fixed, the element sizes in one pool and
 * 			the number of pool elements per pool are set on construction.
 * 			The full amount of memory is allocated on construction.
 * 			The overhead is 4 byte per pool element to store the size
 * 			information of each stored element.
 * 			To maintain an "empty" information, the pool size is limited to
 * 			0xFFFF-1 bytes.
 * 			It is possible to store empty packets in the pool.
 * 			The local pool is NOT thread-safe.
 * @author 	Bastian Baetz
 */

template<uint8_t NUMBER_OF_POOLS = 5>
class LocalPool: public SystemObject, public StorageManagerIF {
public:
	/**
	 * @brief	This definition generally sets the number of different sized pools.
	 * @details This must be less than the maximum number of pools (currently 0xff).
	 */
	//	static const uint32_t NUMBER_OF_POOLS;
	/**
	 * @brief	This is the default constructor for a pool manager instance.
	 * @details	By passing two arrays of size NUMBER_OF_POOLS, the constructor
	 * 			allocates memory (with \c new) for store and size_list. These
	 * 			regions are all set to zero on start up.
	 * @param setObjectId	The object identifier to be set. This allows for
	 * 						multiple instances of LocalPool in the system.
	 * @param element_sizes	An array of size NUMBER_OF_POOLS in which the size
	 * 						of a single element in each pool is determined.
	 * 						<b>The sizes must be provided in ascending order.
	 * 						</b>
	 * @param n_elements	An array of size NUMBER_OF_POOLS in which the
	 * 						number of elements for each pool is determined.
	 * 						The position of these values correspond to those in
	 * 						element_sizes.
	 * @param registered	Register the pool in object manager or not. Default is false (local pool).
	 * @param spillsToHigherPools
	 * 						A variable to determine whether higher n pools are used if the store is full.
	 */
	LocalPool(object_id_t setObjectId,
			const uint16_t element_sizes[NUMBER_OF_POOLS],
			const uint16_t n_elements[NUMBER_OF_POOLS],
			bool registered = false,
			bool spillsToHigherPools = false);
	/**
	 * @brief	In the LocalPool's destructor all allocated memory is freed.
	 */
	virtual ~LocalPool(void);

	/**
	 * Documentation: See StorageManagerIF.h
	 */
	ReturnValue_t addData(store_address_t* storageId, const uint8_t * data,
			size_t size, bool ignoreFault = false) override;
	ReturnValue_t getFreeElement(store_address_t* storageId,const size_t size,
			uint8_t** p_data, bool ignoreFault = false) override;

	ConstAccessorPair getData(store_address_t packet_id) override;
	ReturnValue_t getData(store_address_t packet_id, ConstStorageAccessor&) override;
	ReturnValue_t getData(store_address_t packet_id, const uint8_t** packet_ptr,
			size_t * size) override;

	AccessorPair modifyData(store_address_t packet_id) override;
	ReturnValue_t modifyData(store_address_t packet_id, StorageAccessor&) override;
	ReturnValue_t modifyData(store_address_t packet_id, uint8_t** packet_ptr,
			size_t * size) override;

	virtual ReturnValue_t deleteData(store_address_t) override;
	virtual ReturnValue_t deleteData(uint8_t* ptr, size_t size,
			store_address_t* storeId = NULL) override;
	void clearStore() override;
	ReturnValue_t initialize() override;
protected:
	/**
	 * With this helper method, a free element of \c size is reserved.
	 * @param size	The minimum packet size that shall be reserved.
	 * @param[out] address Storage ID of the reserved data.
	 * @return	- #RETURN_OK on success,
	 * 			- the return codes of #getPoolIndex or #findEmpty otherwise.
	 */
	virtual ReturnValue_t reserveSpace(const uint32_t size,
			store_address_t* address, bool ignoreFault);

	InternalErrorReporterIF *internalErrorReporter;
private:
	/**
	 * Indicates that this element is free.
	 * This value limits the maximum size of a pool. Change to larger data type if increase is required.
	 */
	static const uint32_t STORAGE_FREE = 0xFFFFFFFF;
	/**
	 * @brief	In this array, the element sizes of each pool is stored.
	 * @details	The sizes are maintained for internal pool management. The sizes
	 * 			must be set in ascending order on construction.
	 */
	uint32_t element_sizes[NUMBER_OF_POOLS];
	/**
	 * @brief	n_elements stores the number of elements per pool.
	 * @details	These numbers are maintained for internal pool management.
	 */
	uint16_t n_elements[NUMBER_OF_POOLS];
	/**
	 * @brief	store represents the actual memory pool.
	 * @details	It is an array of pointers to memory, which was allocated with
	 * 			a \c new call on construction.
	 */
	uint8_t* store[NUMBER_OF_POOLS];
	/**
	 * @brief	The size_list attribute stores the size values of every pool element.
	 * @details	As the number of elements is determined on construction, the size list
	 * 			is also dynamically allocated there.
	 */
	uint32_t* size_list[NUMBER_OF_POOLS];
	bool spillsToHigherPools; //!< A variable to determine whether higher n pools are used if the store is full.
	/**
	 * @brief	This method safely stores the given data in the given packet_id.
	 * @details	It also sets the size in size_list. The method does not perform
	 * 			any range checks, these are done in advance.
	 * @param packet_id	The storage identifier in which the data shall be stored.
	 * @param data		The data to be stored.
	 * @param size		The size of the data to be stored.
	 */
	void write(store_address_t packet_id, const uint8_t* data, size_t size);
	/**
	 * @brief	A helper method to read the element size of a certain pool.
	 * @param pool_index	The pool in which to look.
	 * @return	Returns the size of an element or 0.
	 */
	uint32_t getPageSize(uint16_t pool_index);
	/**
	 * @brief	This helper method looks up a fitting pool for a given size.
	 * @details	The pools are looked up in ascending order, so the first that
	 * 			fits is used.
	 * @param packet_size	The size of the data to be stored.
	 * @return	Returns the pool that fits or StorageManagerIF::INVALID_ADDRESS.
	 */
	/**
	 * @brief	This helper method looks up a fitting pool for a given size.
	 * @details	The pools are looked up in ascending order, so the first that
	 * 			fits is used.
	 * @param packet_size		The size of the data to be stored.
	 * @param[out] poolIndex	The fitting pool index found.
	 * @return	- #RETURN_OK on success,
	 * 			- #DATA_TOO_LARGE otherwise.
	 */
	ReturnValue_t getPoolIndex(size_t packet_size, uint16_t* poolIndex,
			uint16_t startAtIndex = 0);
	/**
	 * @brief	This helper method calculates the true array position in store
	 * 			of a given packet id.
	 * @details	The method does not perform any range checks, these are done in
	 * 			advance.
	 * @param packet_id	The packet id to look up.
	 * @return	Returns the position of the data in store.
	 */
	uint32_t getRawPosition(store_address_t packet_id);
	/**
	 * @brief	This is a helper method to find an empty element in a given pool.
	 * @details	The method searches size_list for the first empty element, so
	 * 			duration grows with the fill level of the pool.
	 * @param pool_index	The pool in which the search is performed.
	 * @param[out] element	The first found element in the pool.
	 * @return	- #RETURN_OK on success,
	 * 			- #DATA_STORAGE_FULL if the store is full
	 */
	ReturnValue_t findEmpty(uint16_t pool_index, uint16_t* element);
};

#include <framework/storagemanager/LocalPool.tpp>

#endif /* FRAMEWORK_STORAGEMANAGER_LOCALPOOL_H_ */