include/bip_buf.h

   1 #ifndef BIP_BUF_H_
   2 #define BIP_BUF_H_
   3 /* Author: Domen Puncer Kugler <domen@cba.si>.  License: WTFPL, see file LICENSE */
   4
   5 #include <types.h>
   6
   7 struct bip_buf {
   8         u8 *data;
   9         unsigned size;
  10         volatile unsigned head; /* points to first free byte */
  11         volatile unsigned tail; /* points to first used byte */
  12         volatile unsigned tailwrap;
  13         /* extreme case tail == head: all free;
  14          * tail == head+1: all full (last byte can't be used)
  15          * ____tailxxxxxxxxhead_____
  16          * xxxxhead________tailxxxxx
  17          */
  18 };
  19
  20 void bip_buf_init(struct bip_buf *cb, void *buf, unsigned size);
  21
  22 void* bip_buf_alloc(struct bip_buf *cb, unsigned len);
  23 /* len here must be exactly the same as for _alloc() */
  24 void bip_buf_alloc_commit(struct bip_buf *cb, unsigned len);
  25
  26 void* bip_buf_getdata(struct bip_buf *cb);
  27 void bip_buf_free(struct bip_buf *cb, unsigned len);
  28
  29 #endif