lib/libspl/include/sys/wmsum.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * This file and its contents are supplied under the terms of the
   5  * Common Development and Distribution License ("CDDL"), version 1.0.
   6  * You may only use this file in accordance with the terms of version
   7  * 1.0 of the CDDL.
   8  *
   9  * A full copy of the text of the CDDL should have accompanied this
  10  * source.  A copy of the CDDL is also available via the Internet at
  11  * http://www.illumos.org/license/CDDL.
  12  *
  13  * CDDL HEADER END
  14  */
  15
  16 /*
  17  * wmsum counters are a reduced version of aggsum counters, optimized for
  18  * write-mostly scenarios.  They do not provide optimized read functions,
  19  * but instead allow much cheaper add function.  The primary usage is
  20  * infrequently read statistic counters, not requiring exact precision.
  21  *
  22  * In user-space due to lack of better implementation mapped to aggsum.
  23  */
  24
  25 #ifndef _SYS_WMSUM_H
  26 #define _SYS_WMSUM_H
  27
  28 #include <sys/aggsum.h>
  29
  30 #ifdef  __cplusplus
  31 extern "C" {
  32 #endif
  33
  34 #define wmsum_t aggsum_t
  35
  36 static inline void
  37 wmsum_init(wmsum_t *ws, uint64_t value)
  38 {
  39
  40         aggsum_init(ws, value);
  41 }
  42
  43 static inline void
  44 wmsum_fini(wmsum_t *ws)
  45 {
  46
  47         aggsum_fini(ws);
  48 }
  49
  50 static inline uint64_t
  51 wmsum_value(wmsum_t *ws)
  52 {
  53
  54         return (aggsum_value(ws));
  55 }
  56
  57 static inline void
  58 wmsum_add(wmsum_t *ws, int64_t delta)
  59 {
  60
  61         aggsum_add(ws, delta);
  62 }
  63
  64 #ifdef  __cplusplus
  65 }
  66 #endif
  67
  68 #endif /* _SYS_WMSUM_H */