fsfw/datapoolglob/PoolRawAccess.h

#ifndef POOLRAWACCESS_H_
#define POOLRAWACCESS_H_

#include "../datapool/DataSetIF.h"
#include "../datapool/PoolEntryIF.h"
#include "../datapool/PoolVariableIF.h"
#include "../globalfunctions/Type.h"

/**
 * @brief This class allows accessing Data Pool variables as raw bytes.
 * @details
 * This is necessary to have an access method for HK data, as the PID's alone
 * do not provide type information. Please note that the the raw pool access
 * read() and commit() calls are not thread-safe.
 *
 * Please supply a data set and use the data set read(), commit() calls for
 * thread-safe data pool access.
 * @ingroup data_pool
 */
class PoolRawAccess: public PoolVariableIF, HasReturnvaluesIF {
public:
	/**
	 * This constructor is used to access a data pool entry with a
	 * given ID if the target type is not known. A DataSet object is supplied
	 * and the data pool entry with the given ID is registered to that data set.
	 * Please note that a pool raw access buffer only has a buffer
	 * with a size of double. As such, for vector entries which have
	 * @param data_pool_id Target data pool entry ID
	 * @param arrayEntry
	 * @param data_set Dataset to register data pool entry to
	 * @param setReadWriteMode
	 * @param registerVectors If set to true, the constructor checks if
	 *                        there are multiple vector entries to registers
	 *                        and registers all of them recursively into the data_set
	 *
	 */
	PoolRawAccess(uint32_t data_pool_id, uint8_t arrayEntry,
			DataSetIF* data_set, ReadWriteMode_t setReadWriteMode =
					PoolVariableIF::VAR_READ);

	/**
	 * @brief	This operation returns a pointer to the entry fetched.
	 * @details	Return pointer to the buffer containing the raw data
	 *          Size and number of data can be retrieved by other means.
	 */
	uint8_t* getEntry();
	/**
	 * @brief 	This operation returns the fetched entry from the data pool and
	 * 			flips the bytes, if necessary.
	 * @details	It makes use of the getEntry call of this function, but additionally flips the
	 * 			bytes to big endian, which is the default for external communication (as House-
	 * 			keeping telemetry). To achieve this, the data is copied directly to the passed
	 * 			buffer, if it fits in the given max_size.
	 * @param buffer	A pointer to a buffer to write to
	 * @param writtenBytes	The number of bytes written is returned with this value.
	 * @param max_size	The maximum size that the function may write to buffer.
	 * @return	- @c RETURN_OK if entry could be acquired
	 * 			- @c RETURN_FAILED else.
	 */
	ReturnValue_t getEntryEndianSafe(uint8_t *buffer, size_t *size,
			size_t maxSize);

	/**
	 * @brief 	Serialize raw pool entry into provided buffer directly
	 * @param buffer Provided buffer. Raw pool data will be copied here
	 * @param size [out] Increment provided size value by serialized size
	 * @param max_size Maximum allowed serialization size
	 * @param bigEndian Specify endianess
	 * @return - @c RETURN_OK if serialization was successfull
	 *         - @c SerializeIF::BUFFER_TOO_SHORT if range check failed
	 */
	ReturnValue_t serialize(uint8_t **buffer, size_t *size,
	        size_t maxSize, Endianness streamEndianness) const override;

    size_t getSerializedSize() const override;

    ReturnValue_t deSerialize(const uint8_t **buffer, size_t *size,
            Endianness streamEndianness) override;

	/**
	 * With this method, the content can be set from a big endian buffer safely.
	 * @param buffer	Pointer to the data to set
	 * @param size		Size of the data to write. Must fit this->size.
	 * @return	- @c RETURN_OK on success
	 * 			- @c RETURN_FAILED on failure
	 */
	ReturnValue_t setEntryFromBigEndian(const uint8_t* buffer,
			size_t setSize);
	/**
	 *  @brief This operation returns the type of the entry currently stored.
	 */
	Type getType();
	/**
	 *  @brief This operation returns the size of the entry currently stored.
	 */
	size_t getSizeOfType();
	/**
	 *
	 * @return the size of the datapool array
	 */
	size_t getArraySize();
	/**
	 * @brief	This operation returns the data pool id of the variable.
	 */
	uint32_t getDataPoolId() const;

	static const uint8_t INTERFACE_ID = CLASS_ID::POOL_RAW_ACCESS_CLASS;
	static const ReturnValue_t INCORRECT_SIZE = MAKE_RETURN_CODE(0x01);
	static const ReturnValue_t DATA_POOL_ACCESS_FAILED = MAKE_RETURN_CODE(0x02);
	static const ReturnValue_t READ_TYPE_TOO_LARGE = MAKE_RETURN_CODE(0x03);
	static const ReturnValue_t READ_INDEX_TOO_LARGE = MAKE_RETURN_CODE(0x04);
	static const ReturnValue_t READ_ENTRY_NON_EXISTENT =  MAKE_RETURN_CODE(0x05);
	static const uint8_t RAW_MAX_SIZE = sizeof(double);
	uint8_t value[RAW_MAX_SIZE];


	/**
	 * @brief	The classes destructor is empty. If commit() was not called, the local value is
	 * 			discarded and not written back to the data pool.
	 */
	~PoolRawAccess();

	/**
	 * This method returns if the variable is read-write or read-only.
	 */
	ReadWriteMode_t getReadWriteMode() const;
	/**
	 * @brief	With this call, the valid information of the variable is returned.
	 */
	bool isValid() const;

	void setValid(bool valid);
	/**
	 * Getter for the remaining size.
	 */
	size_t getSizeTillEnd() const;

	/**
	 * @brief	This is a call to read the value from the global data pool.
	 * @details
	 * When executed, this operation tries to fetch the pool entry with matching
	 * data pool id from the global data pool and copies the value and the valid
	 * information to its local attributes. In case of a failure (wrong type or
	 * pool id not found), the variable is set to zero and invalid.
	 * The call is protected by a lock of the global data pool.
	 * @return -@c RETURN_OK Read successfull
	 * 		   -@c READ_TYPE_TOO_LARGE
	 * 		   -@c READ_INDEX_TOO_LARGE
	 * 		   -@c READ_ENTRY_NON_EXISTENT
	 */
	ReturnValue_t read(uint32_t lockTimeout = MutexIF::BLOCKING) override;
	/**
	 * @brief	The commit call writes back the variable's value to the data pool.
	 * @details
	 * It checks type and size, as well as if the variable is writable. If so,
	 * the value is copied and the valid flag is automatically set to "valid".
	 * The call is protected by a lock of the global data pool.
	 *
	 */
	ReturnValue_t commit(uint32_t lockTimeout = MutexIF::BLOCKING) override;

protected:
	/**
	 * @brief	Like #read, but without a lock protection of the global pool.
	 * @details
	 * The operation does NOT provide any mutual exclusive protection by itself.
	 * This can be used if the lock is handled externally to avoid the overhead
	 * of consecutive lock und unlock operations.
	 * Declared protected to discourage free public usage.
	 */
	ReturnValue_t readWithoutLock() override;
	/**
	 * @brief	Like #commit, but without a lock protection of the global pool.
	 * @details
	 * The operation does NOT provide any mutual exclusive protection by itself.
	 * This can be used if the lock is handled externally to avoid the overhead
	 * of consecutive lock und unlock operations.
	 * Declared protected to discourage free public usage.
	 */
	ReturnValue_t commitWithoutLock() override;

	ReturnValue_t handleReadOut(PoolEntryIF* read_out);
	void handleReadError(ReturnValue_t result);
private:
	/**
	 * @brief	To access the correct data pool entry on read and commit calls, the data pool id
	 * 			is stored.
	 */
	uint32_t dataPoolId;
	/**
	 * @brief	The array entry that is fetched from the data pool.
	 */
	uint8_t arrayEntry;
	/**
	 * @brief	The valid information as it was stored in the data pool is copied to this attribute.
	 */
	uint8_t valid;
	/**
	 * @brief	This value contains the type of the data pool entry.
	 */
	Type type;
	/**
	 * @brief	This value contains the size of the data pool entry type in bytes.
	 */
	size_t typeSize;
	/**
	 * The size of the DP array (single values return 1)
	 */
	size_t arraySize;
	/**
	 * The size (in bytes) from the selected entry till the end of this DataPool variable.
	 */
	size_t sizeTillEnd;
	/**
	 * @brief	The information whether the class is read-write or read-only is stored here.
	 */
	ReadWriteMode_t readWriteMode;
};

#endif /* POOLRAWACCESS_H_ */