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IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #ifndef SYS_RINGBUFFER_H_INCLUDED #define SYS_RINGBUFFER_H_INCLUDED #include #include #include /** @file * This file contains declarations of the Ring buffer routines and necessary types. Please note that * each ring buffer element should have size of 1 byte. * * @defgroup sys_ringbuffer System Ring buffer API * @ingroup sys_15_4 * @{ * @brief Module for declaring System Ring buffer API. * @details The Ring Buffer module implements routines to deal with the ring buffer. The following routines are supported: * sys_ringbuffer_insert(), sys_ringbuffer_remove() to operate with single element. The * sys_ringbuffer_remove_multiple() can be used to remove (read) several elements at once. The * sys_ringbuffer_clear(), sys_ringbuffer_init(), and sys_ringbuffer_init_over() functions are used to clean up and * initialize the ring buffer. Some information about the initialized ring buffer is available via the * following routines: sys_ringbuffer_size_get() to get the number of used elements, sys_ringbuffer_chunk_get() * to return the biggest, available to read, continuous chunk of elements, sys_ringbuffer_is_empty() and * sys_ringbuffer_is_full() to check if the ring buffer is empty/full, and sys_ringbuffer_max_size_get() to get * the ring buffer capacity. One of the samples for ring buffer usage is the UART implementation. */ /** This structure holds all necessary information about a ring buffer. It is intentionally left undocumented * by Doxygen. * * All these fields are private and must NOT be changed by the user. */ typedef struct { size_t write_index; size_t read_index; uint8_t * array; size_t size; bool is_full; } sys_ringbuffer_t; /** @brief Function for initializing an empty ring buffer over passed memory. * * @param[inout] buffer Instance of sys_ringbuffer_t that will be initialized. * @param[in] memory Start address of the memory region used as a ring buffer. * @param[in] length Size in bytes of the memory region used as a ring buffer. */ void sys_ringbuffer_init(sys_ringbuffer_t * buffer, const void * memory, const size_t length); /** @brief Function for initializing a ring buffer over passed memory and marking all * pre_init_length elements as inserted. * * @details This function may be used to initialize a buffer with some * pre-initialized data in it. Passed memory region is interpreted by this function * as an already filled (partly or fully) ring buffer so that \a pre_init_length * elements are marked as inserted. * * @param[inout] buffer Instance of sys_ringbuffer_t that will be initialized. * @param[in] memory Start address of the memory region used as a ring buffer. * @param[in] pre_init_length Number of elements (bytes) that had already been in \a memory. * They would be inserted into the newly-initialized ring buffer in a FIFO manner. * @param[in] length Size of the memory region used as a ring buffer. */ void sys_ringbuffer_init_over(sys_ringbuffer_t * buffer, const void * memory, const size_t pre_init_length, const size_t length); /** @brief Function for removing an element from a ring buffer and returning it. * * @param[inout] buf Instance of @c sys_ringbuffer_t. * * @return Value of the removed element. * * @warning This buffer has no underflow control except assert. */ uint8_t sys_ringbuffer_remove(sys_ringbuffer_t * buf); /** @brief Function for quickly removing up to chunk_size elements from a ring buffer * and marking those elements as available in the ring buffer. * * @param[inout] buffer Instance of @c sys_ringbuffer_t. * @param[in] chunk_size Number of elements to release. */ void sys_ringbuffer_remove_multiple(sys_ringbuffer_t * buffer, const size_t chunk_size); /** @brief Function for inserting a new element into a ring buffer. * * @param[inout] buffer Instance of @c sys_ringbuffer_t. * @param[in] data Element value to insert. * * @warning In case of overflow, this buffer will overwrite the oldest * element and the number of available elements will remain unchanged. */ void sys_ringbuffer_insert(sys_ringbuffer_t * buffer, const uint8_t data); /** @brief Function for clearing an instance of \a sys_ringbuffer_t, making it empty. * * @param[inout] buffer Instance of @c sys_ringbuffer_t. */ void sys_ringbuffer_clear(sys_ringbuffer_t * buffer); /** @brief Function for returning the number of used elements in a ring buffer instance. * * @param[inout] buf Instance of sys_ringbuffer_t. * * @return Number of elements. */ size_t sys_ringbuffer_size_get(const sys_ringbuffer_t * buf); /** @brief Function for returning the biggest, available to read, continuous chunk from a ring buffer array. * * @param[inout] buffer Instance of @c sys_ringbuffer_t. * @param[out] chunk Pointer to a memory chunk removed from the ring buffer. * @param[out] chunk_size Size of the removed chunk. * * @warning The returned chunk is still part of the ring buffer. To make the chunk elements available * for write, call @c sys_ringbuffer_remove_multiple() after the chunk is processed. */ void sys_ringbuffer_chunk_get(sys_ringbuffer_t * buffer, void ** chunk, size_t * chunk_size); /** @brief Function for checking whether a ring buffer is empty. * * @param[inout] buf Instance of @c sys_ringbuffer_t. * * @return True if the ring buffer is empty. */ static inline bool sys_ringbuffer_is_empty(const sys_ringbuffer_t * buf) { return ((buf->write_index == buf->read_index) && (!buf->is_full)); } /** @brief Function for checking whether a ring buffer is full. * * @param[inout] buf Instance of @c sys_ringbuffer_t. * * @return True if number of items in the buffer equals to (length - 1). */ static inline bool sys_ringbuffer_is_full(const sys_ringbuffer_t * buf) { return buf->is_full; } /** @brief Function for returning number of elements that can be potentially put into the buffer. * * @param[inout] buf Instance of @c sys_ringbuffer_t. * * @return Number of elements. */ static inline size_t sys_ringbuffer_max_size_get(const sys_ringbuffer_t * buf) { return buf->size; } /** @} */ #endif /* SYS_RINGBUFFER_H_INCLUDED */