git.squeep.com Git - reservoir_sample/blob - reservoir.h

   1 #ifndef RESERVOIR_H_MZSA8WJ3
   2 #define RESERVOIR_H_MZSA8WJ3
   3
   4 #include <stdlib.h>
   5
   6 #include "buf.h"
   7
   8 #ifndef NDEBUG
   9 #include "notify.h"
  10 #endif /* NDEBUG */
  11
  12 /* A pool of buf_t */
  13
  14 typedef struct reservoir_ {
  15         size_t reservoir_sz; /* allocated slots */
  16         size_t reservoir_used; /* slots filled */
  17         unsigned long reservoir_tally; /* total number of items remembered */
  18         buf_t reservoir[];
  19 } *reservoir_t;
  20
  21 #ifndef NDEBUG
  22 #define D_RESERVOIR(__r__) do {\
  23         size_t i;\
  24                 NOTIFY_DEBUG("reservoir:%p sz: %zu used:%zu tally:%zu", (__r__), (__r__)->reservoir_sz, (__r__)->reservoir_used, (__r__)->reservoir_tally);\
  25                 for (i = 0; i < (__r__)->reservoir_sz; i++) {\
  26                         D_BUF("reservoir[%zu] ", (__r__)->reservoir[i], i);\
  27                 }\
  28 } while (0)
  29 #else /* NDEBUG */
  30 #define D_RESERVOIR(...)
  31 #endif /* NDEBUG */
  32
  33 /*      reservoir_new
  34         Allocate and return a new reservoir capable of holding #sz bufs.
  35 */
  36 reservoir_t reservoir_new(size_t sz);
  37
  38 /*      reservoir_grow
  39         Increase the storage capacity of the reservoir pointed to by #preservoir
  40         by #growby bufs.
  41 */
  42 int reservoir_grow(reservoir_t *preservoir, size_t growby);
  43
  44 /*      reservoir_remember
  45                 Remember #buf, forgetting another buf at random if the reservoir
  46                 pointed to by #preservoir is already full to capacity.
  47 */
  48 void reservoir_remember(reservoir_t reservoir, buf_t buf);
  49
  50 /*      reservoir_write
  51         Write the contents of the bufs within #reservoir to #fd, each with a
  52         trailing #delim.
  53 */
  54 int reservoir_write(int fd, reservoir_t reservoir, char delim);
  55
  56 /*      reservoir_write_meta
  57         Write metadata of #reservoir and #samples to fd.
  58 */
  59 int reservoir_write_meta(int fd, reservoir_t reservoir, unsigned long samples, char delim);
  60
  61 #endif /* RESERVOIR_H_MZSA8WJ3 */