mirror of
https://github.com/stargieg/bacnet-stack
synced 2025-10-26 23:35:52 +08:00
92 lines
2.4 KiB
C
92 lines
2.4 KiB
C
/**
|
|
* @file
|
|
* @author Steve Karg
|
|
* @date 2004
|
|
*
|
|
* Generic ring buffer library for deeply embedded system.
|
|
* See the unit tests for usage examples.
|
|
*/
|
|
#ifndef RINGBUF_H
|
|
#define RINGBUF_H
|
|
|
|
#include <stdint.h>
|
|
#include <stdbool.h>
|
|
|
|
/**
|
|
* ring buffer power of two alignment macro
|
|
*
|
|
* @{
|
|
*/
|
|
#ifndef NEXT_POWER_OF_2
|
|
#define B2(x) ( (x) | ( (x) >> 1) )
|
|
#define B4(x) ( B2(x) | ( B2(x) >> 2) )
|
|
#define B8(x) ( B4(x) | ( B4(x) >> 4) )
|
|
#define B16(x) ( B8(x) | ( B8(x) >> 8) )
|
|
#define B32(x) (B16(x) | (B16(x) >>16) )
|
|
#define NEXT_POWER_OF_2(x) (B32((x)-1) + 1)
|
|
#endif
|
|
/** @} */
|
|
|
|
/**
|
|
* ring buffer data structure
|
|
*
|
|
* @{
|
|
*/
|
|
struct ring_buffer_t {
|
|
/** block of memory or array of data */
|
|
volatile uint8_t *buffer;
|
|
/** how many bytes for each chunk */
|
|
unsigned element_size;
|
|
/** number of chunks of data */
|
|
unsigned element_count;
|
|
/** where the writes go */
|
|
volatile unsigned head;
|
|
/** where the reads come from */
|
|
volatile unsigned tail;
|
|
/* maximum depth reached */
|
|
volatile unsigned depth;
|
|
};
|
|
typedef struct ring_buffer_t RING_BUFFER;
|
|
/** @} */
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif /* __cplusplus */
|
|
|
|
unsigned Ringbuf_Count(RING_BUFFER const *b);
|
|
unsigned Ringbuf_Depth(RING_BUFFER const *b);
|
|
unsigned Ringbuf_Depth_Reset(RING_BUFFER *b);
|
|
unsigned Ringbuf_Size(RING_BUFFER const *b);
|
|
bool Ringbuf_Full(RING_BUFFER const *b);
|
|
bool Ringbuf_Empty(RING_BUFFER const *b);
|
|
/* tail */
|
|
volatile uint8_t *Ringbuf_Peek(RING_BUFFER const *b);
|
|
bool Ringbuf_Pop(RING_BUFFER * b,
|
|
uint8_t * data_element);
|
|
bool Ringbuf_Put_Front(RING_BUFFER * b,
|
|
uint8_t * data_element);
|
|
/* head */
|
|
bool Ringbuf_Put(RING_BUFFER * b,
|
|
uint8_t * data_element);
|
|
/* pair of functions to use head memory directly */
|
|
volatile uint8_t *Ringbuf_Data_Peek(RING_BUFFER * b);
|
|
bool Ringbuf_Data_Put(RING_BUFFER * b, volatile uint8_t *data_element);
|
|
/* Note: element_count must be a power of two */
|
|
bool Ringbuf_Init(RING_BUFFER * b,
|
|
volatile uint8_t * buffer,
|
|
unsigned element_size,
|
|
unsigned element_count);
|
|
|
|
#ifdef TEST
|
|
#include "ctest.h"
|
|
void testRingBufPowerOfTwo(Test * pTest);
|
|
void testRingBufSizeSmall(Test * pTest);
|
|
void testRingBufSizeLarge(Test * pTest);
|
|
void testRingBufSizeInvalid(Test * pTest);
|
|
#endif
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif /* __cplusplus */
|
|
#endif
|