lib/buffer.h

   1 /*
   2  *      BIRD Library -- Generic Buffer Structure
   3  *
   4  *      (c) 2013 Ondrej Zajicek <santiago@crfreenet.org>
   5  *      (c) 2013 CZ.NIC z.s.p.o.
   6  *
   7  *      Can be freely distributed and used under the terms of the GNU GPL.
   8  */
   9
  10 #ifndef _BIRD_BUFFER_H_
  11 #define _BIRD_BUFFER_H_
  12
  13 #include "lib/resource.h"
  14 #include "sysdep/config.h"
  15
  16 #define BUFFER(type)            struct { type *data; uint used, size; }
  17
  18 #define BUFFER_SIZE(v)          ((v).size * sizeof(* (v).data))
  19
  20 #define BUFFER_INIT(v,pool,isize)                                       \
  21   ({                                                                    \
  22     (v).used = 0;                                                       \
  23     (v).size = (isize);                                                 \
  24     (v).data = mb_alloc(pool, BUFFER_SIZE(v));                          \
  25   })
  26
  27 #define BUFFER_SET(v,nsize)                                             \
  28   ({                                                                    \
  29     (v).used = (nsize);                                                 \
  30     if ((v).used > (v).size)                                            \
  31       buffer_realloc((void **) &((v).data), &((v).size), (v).used, sizeof(* (v).data)); \
  32   })
  33
  34 #define BUFFER_INC(v,step)                                              \
  35   ({                                                                    \
  36     uint _o = (v).used;                                                 \
  37     BUFFER_SET(v, (v).used + (step));                                   \
  38     (v).data + _o;                                                      \
  39   })
  40
  41 #define BUFFER_DEC(v,step)      ({ (v).used -= (step); })
  42
  43 #define BUFFER_PUSH(v)          (*BUFFER_INC(v,1))
  44
  45 #define BUFFER_POP(v)           BUFFER_DEC(v,1)
  46
  47 #define BUFFER_FLUSH(v)         ({ (v).used = 0; })
  48
  49 #endif /* _BIRD_BUFFER_H_ */