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/*
* ring.h:
*
* Copyright (c) 2008 James McKenzie <james@fishsoup.dhs.org>,
* All rights reserved.
*
*/
/*
* $Id$
*/
/*
* $Log$
* Revision 1.1 2008/02/08 15:06:42 james
* *** empty log message ***
*
*/
#ifndef __RING_H__
#define __RING_H__
typedef struct {
uint8_t *ring;
int wptr;
int rptr;
int size;
} Ring;
#define RING_NEXT(r,a) (((a)+1) % ((r)->size))
#define RING_NEXT_R(r) RING_NEXT(r,r->rptr)
#define RING_NEXT_W(r) RING_NEXT(r,r->wptr)
#define RING_EMPTY(r) (((r)->wptr) == ((r)->rptr))
#define RING_FULL(r) (RING_NEXT_W(r) == ((r)->rptr))
static inline int ring_write_one(Ring *r,uint8_t *c)
{
if (RING_FULL(r)) return 0;
r->ring[r->wptr++]=*c;
if (r->wptr==r->size)
r->wptr=0;
}
return 1;
}
static inline int ring_read_one(Ring *r,uint8_t *c)
{
if (RING_EMPTY(r)) return 0;
*c=r->ring[r->rptr++];
if (r->rptr==r->size)
r->rptr=0;
}
return 1;
}
#endif /* __RING_H__ */
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