diff options
Diffstat (limited to 'src/ring.h')
-rw-r--r-- | src/ring.h | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/src/ring.h b/src/ring.h new file mode 100644 index 0000000..d0dd3a0 --- /dev/null +++ b/src/ring.h @@ -0,0 +1,65 @@ +/* + * 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__ */ |