2 * collectd - src/utils_time.h
3 * Copyright (C) 2010 Florian octo Forster
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 * Florian octo Forster <ff at octo.it>
23 #define UTILS_TIME_H 1
28 * "cdtime_t" is a 64bit unsigned integer. The time is stored at a 2^-30 second
29 * resolution, i.e. the most significant 34 bit are used to store the time in
30 * seconds, the least significant bits store the sub-second part in something
31 * very close to nanoseconds. *The* big advantage of storing time in this
32 * manner is that comparing times and calculating differences is as simple as
33 * it is with "time_t", i.e. a simple integer comparison / subtraction works.
36 * cdtime_t is defined in "collectd.h" */
37 /* typedef uint64_t cdtime_t; */
39 /* 2^30 = 1073741824 */
40 #define TIME_T_TO_CDTIME_T(t) (((cdtime_t) (t)) * 1073741824)
41 #define CDTIME_T_TO_TIME_T(t) ((time_t) ((t) / 1073741824))
43 #define CDTIME_T_TO_DOUBLE(t) (((double) (t)) / 1073741824.0)
44 #define DOUBLE_TO_CDTIME_T(d) ((cdtime_t) ((d) * 1073741824.0))
46 #define MS_TO_CDTIME_T(ms) ((cdtime_t) (((double) (ms)) * 1073741.824))
47 #define CDTIME_T_TO_MS(t) ((long) (((double) (t)) / 1073741.824))
48 #define US_TO_CDTIME_T(us) ((cdtime_t) (((double) (us)) * 1073.741824))
49 #define CDTIME_T_TO_US(t) ((suseconds_t) (((double) (t)) / 1073.741824))
50 #define NS_TO_CDTIME_T(ns) ((cdtime_t) (((double) (ns)) * 1.073741824))
51 #define CDTIME_T_TO_NS(t) ((long) (((double) (t)) / 1.073741824))
53 #define CDTIME_T_TO_TIMEVAL(cdt,tvp) do { \
54 (tvp)->tv_sec = CDTIME_T_TO_TIME_T (cdt); \
55 (tvp)->tv_usec = CDTIME_T_TO_US ((cdt) % 1073741824); \
57 #define TIMEVAL_TO_CDTIME_T(tv) (TIME_T_TO_CDTIME_T ((tv)->tv_sec) \
58 + US_TO_CDTIME_T ((tv)->tv_usec))
60 #define CDTIME_T_TO_TIMESPEC(cdt,tsp) do { \
61 (tsp)->tv_sec = CDTIME_T_TO_TIME_T (cdt); \
62 (tsp)->tv_nsec = CDTIME_T_TO_NS ((cdt) % 1073741824); \
64 #define TIMESPEC_TO_CDTIME_T(ts) (TIME_T_TO_CDTIME_T ((ts)->tv_sec) \
65 + NS_TO_CDTIME_T ((ts)->tv_nsec))
67 cdtime_t cdtime (void);
69 /* format a cdtime_t value in ISO 8601 format:
70 * returns the number of characters written to the string (not including the
71 * terminating null byte or 0 on error; the function ensures that the string
72 * is null terminated */
73 size_t cdtime_to_iso8601 (char *s, size_t max, cdtime_t t);
75 #endif /* UTILS_TIME_H */
76 /* vim: set sw=2 sts=2 et : */