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/*
* ------------------------------------------------------------
* "THE BEERWARE LICENSE" (Revision 42):
* diegohamilton26@gmail.com wrote this code. As long as you retain this
* notice, you can do whatever you want with this stuff. If we
* meet someday, and you think this stuff is worth it, you can
* buy me a beer in return,
* Diego Hamilton.
* ------------------------------------------------------------
*/
#ifndef _CIRCULAR_BUFFER_H
#define _CIRCULAR_BUFFER_H
#include <stddef.h>
/*
* BUF must be a pointer of any buffer with type 'NAME' defined.
* ELEM must be a element (NOT A POINTER) of type T defined.
*/
#define circular_buffer_struct(T, SIZE) \
struct { \
size_t occup; \
size_t size; \
size_t head, tail; \
T data[SIZE]; \
}
#define cb_init(BUF, SIZE) \
do { \
(BUF).size = SIZE; \
(BUF).occup = 0; \
(BUF).head = 0; \
(BUF).tail = 0; \
} while(0)
#define cb_size(BUF) ((BUF).size)
#define cb_full(BUF) ((BUF).occup == (BUF).size)
#define cb_empty(BUF) ((BUF).occup == 0)
#define cb_occupation(BUF) ((BUF).occup)
#define cb_reset(BUF) \
do { \
(BUF).head = 0; \
(BUF).tail = 0; \
(BUF).occup = 0; \
} while(0)
/* TODO: replace occup by calculations w/ head and tail? */
#define cb_push(BUF, ELEM) \
do { \
((BUF).data)[(BUF).tail] = (ELEM); \
if ((BUF).tail == cb_size(BUF) - 1) { \
(BUF).tail = 0; \
} else { \
(BUF).tail = ((BUF).tail + 1); \
} \
if (cb_full((BUF))) { \
if ((BUF).head == cb_size(BUF) - 1) { \
(BUF).head = 0; \
} else { \
(BUF).head = ((BUF).head + 1); \
} \
} else { \
(BUF).occup = (BUF).occup + 1; \
} \
} while(0)
#define cb_pop(BUF, ELEM) \
do { \
if(!cb_empty((BUF))) { \
(ELEM) = (BUF).data[(BUF).head]; \
if ((BUF).head == cb_size(BUF) - 1) { \
(BUF).head = 0; \
} else { \
(BUF).head = ((BUF).head + 1); \
} \
(BUF).occup -= 1; \
} \
} while(0)
#endif
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