/**
* Copyright (c) 2013 - 2017, Nordic Semiconductor ASA
*
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* are permitted provided that the following conditions are met:
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* Semiconductor ASA integrated circuit in a product or a software update for
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* 3. Neither the name of Nordic Semiconductor ASA nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
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* 4. This software, with or without modification, must only be used with a
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* 5. Any software provided in binary form under this license must not be reverse
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/**@file
*
* @defgroup app_fifo FIFO implementation
* @{
* @ingroup app_common
*
* @brief FIFO implementation.
*/
#ifndef APP_FIFO_H__
#define APP_FIFO_H__
#include <stdint.h>
#include <stdlib.h>
#ifdef __cplusplus
extern "C" {
#endif
/**@brief A FIFO instance structure.
* @details Keeps track of which bytes to read and write next.
* Also, it keeps the information about which memory is allocated for the buffer
* and its size. This structure must be initialized by app_fifo_init() before use.
*/
typedef struct
{
uint8_t * p_buf; /**< Pointer to FIFO buffer memory. */
uint16_t buf_size_mask; /**< Read/write index mask. Also used for size checking. */
volatile uint32_t read_pos; /**< Next read position in the FIFO buffer. */
volatile uint32_t write_pos; /**< Next write position in the FIFO buffer. */
} app_fifo_t;
/**@brief Function for initializing the FIFO.
*
* @param[out] p_fifo FIFO object.
* @param[in] p_buf FIFO buffer for storing data. The buffer size must be a power of two.
* @param[in] buf_size Size of the FIFO buffer provided. This size must be a power of two.
*
* @retval NRF_SUCCESS If initialization was successful.
* @retval NRF_ERROR_NULL If a NULL pointer is provided as buffer.
* @retval NRF_ERROR_INVALID_LENGTH If size of buffer provided is not a power of two.
*/
uint32_t app_fifo_init(app_fifo_t * p_fifo, uint8_t * p_buf, uint16_t buf_size);
/**@brief Function for adding an element to the FIFO.
*
* @param[in] p_fifo Pointer to the FIFO.
* @param[in] byte Data byte to add to the FIFO.
*
* @retval NRF_SUCCESS If an element has been successfully added to the FIFO.
* @retval NRF_ERROR_NO_MEM If the FIFO is full.
*/
uint32_t app_fifo_put(app_fifo_t * p_fifo, uint8_t byte);
/**@brief Function for getting the next element from the FIFO.
*
* @param[in] p_fifo Pointer to the FIFO.
* @param[out] p_byte Byte fetched from the FIFO.
*
* @retval NRF_SUCCESS If an element was returned.
* @retval NRF_ERROR_NOT_FOUND If there are no more elements in the queue.
*/
uint32_t app_fifo_get(app_fifo_t * p_fifo, uint8_t * p_byte);
/**@brief Function for looking at an element in the FIFO, without consuming it.
*
* @param[in] p_fifo Pointer to the FIFO.
* @param[in] index Which element to look at. The lower the index, the earlier it was put.
* @param[out] p_byte Byte fetched from the FIFO.
*
* @retval NRF_SUCCESS If an element was returned.
* @retval NRF_ERROR_NOT_FOUND If there are no more elements in the queue, or the index was
* too large.
*/
uint32_t app_fifo_peek(app_fifo_t * p_fifo, uint16_t index, uint8_t * p_byte);
/**@brief Function for flushing the FIFO.
*
* @param[in] p_fifo Pointer to the FIFO.
*
* @retval NRF_SUCCESS If the FIFO was flushed successfully.
*/
uint32_t app_fifo_flush(app_fifo_t * p_fifo);
/**@brief Function for reading bytes from the FIFO.
*
* This function can also be used to get the number of bytes in the FIFO.
*
* @param[in] p_fifo Pointer to the FIFO. Must not be NULL.
* @param[out] p_byte_array Memory pointer where the read bytes are fetched from the FIFO.
* Can be NULL. If NULL, the number of bytes that can be read in the FIFO
* are returned in the p_size parameter.
* @param[inout] p_size Address to memory indicating the maximum number of bytes to be read.
* The provided memory is overwritten with the actual number of bytes
* read if the procedure was successful. This field must not be NULL.
* If p_byte_array is set to NULL by the application, this parameter
* returns the number of bytes in the FIFO.
*
* @retval NRF_SUCCESS If the procedure is successful. The actual number of bytes read might
* be less than the requested maximum, depending on how many elements exist
* in the FIFO. Even if less bytes are returned, the procedure is considered
* successful.
* @retval NRF_ERROR_NULL If a NULL parameter was passed for a parameter that must not
* be NULL.
* @retval NRF_ERROR_NOT_FOUND If the FIFO is empty.
*/
uint32_t app_fifo_read(app_fifo_t * p_fifo, uint8_t * p_byte_array, uint32_t * p_size);
/**@brief Function for writing bytes to the FIFO.
*
* This function can also be used to get the available size on the FIFO.
*
* @param[in] p_fifo Pointer to the FIFO. Must not be NULL.
* @param[in] p_byte_array Memory pointer containing the bytes to be written to the FIFO.
* Can be NULL. If NULL, this function returns the number of bytes
* that can be written to the FIFO.
* @param[inout] p_size Address to memory indicating the maximum number of bytes to be written.
* The provided memory is overwritten with the number of bytes that were actually
* written if the procedure is successful. This field must not be NULL.
* If p_byte_array is set to NULL by the application, this parameter
* returns the number of bytes available in the FIFO.
*
* @retval NRF_SUCCESS If the procedure is successful. The actual number of bytes written might
* be less than the requested maximum, depending on how much room there is in
* the FIFO. Even if less bytes are written, the procedure is considered
* successful. If the write was partial, the application should use
* subsequent calls to attempt writing the data again.
* @retval NRF_ERROR_NULL If a NULL parameter was passed for a parameter that must not
* be NULL.
* @retval NRF_ERROR_NO_MEM If the FIFO is full.
*
*/
uint32_t app_fifo_write(app_fifo_t * p_fifo, uint8_t const * p_byte_array, uint32_t * p_size);
#ifdef __cplusplus
}
#endif
#endif // APP_FIFO_H__
/** @} */