2 * collectd - src/utils_time.h
3 * Copyright (C) 2010 Florian octo Forster
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
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10 * Software is furnished to do so, subject to the following conditions:
12 * The above copyright notice and this permission notice shall be included in
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15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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21 * DEALINGS IN THE SOFTWARE.
24 * Florian octo Forster <ff at octo.it>
28 #define UTILS_TIME_H 1
33 * "cdtime_t" is a 64bit unsigned integer. The time is stored at a 2^-30 second
34 * resolution, i.e. the most significant 34 bit are used to store the time in
35 * seconds, the least significant bits store the sub-second part in something
36 * very close to nanoseconds. *The* big advantage of storing time in this
37 * manner is that comparing times and calculating differences is as simple as
38 * it is with "time_t", i.e. a simple integer comparison / subtraction works.
41 * cdtime_t is defined in "collectd.h" */
42 /* typedef uint64_t cdtime_t; */
44 /* 2^30 = 1073741824 */
45 #define TIME_T_TO_CDTIME_T(t) (((cdtime_t) (t)) * 1073741824)
46 #define CDTIME_T_TO_TIME_T(t) ((time_t) ((t) / 1073741824))
48 #define CDTIME_T_TO_DOUBLE(t) (((double) (t)) / 1073741824.0)
49 #define DOUBLE_TO_CDTIME_T(d) ((cdtime_t) ((d) * 1073741824.0))
51 #define MS_TO_CDTIME_T(ms) ((cdtime_t) (((double) (ms)) * 1073741.824))
52 #define CDTIME_T_TO_MS(t) ((long) (((double) (t)) / 1073741.824))
53 #define US_TO_CDTIME_T(us) ((cdtime_t) (((double) (us)) * 1073.741824))
54 #define CDTIME_T_TO_US(t) ((suseconds_t) (((double) (t)) / 1073.741824))
55 #define NS_TO_CDTIME_T(ns) ((cdtime_t) (((double) (ns)) * 1.073741824))
56 #define CDTIME_T_TO_NS(t) ((long) (((double) (t)) / 1.073741824))
58 #define CDTIME_T_TO_TIMEVAL(cdt,tvp) do { \
59 (tvp)->tv_sec = CDTIME_T_TO_TIME_T (cdt); \
60 (tvp)->tv_usec = CDTIME_T_TO_US ((cdt) % 1073741824); \
62 #define TIMEVAL_TO_CDTIME_T(tv) (TIME_T_TO_CDTIME_T ((tv)->tv_sec) \
63 + US_TO_CDTIME_T ((tv)->tv_usec))
65 #define CDTIME_T_TO_TIMESPEC(cdt,tsp) do { \
66 (tsp)->tv_sec = CDTIME_T_TO_TIME_T (cdt); \
67 (tsp)->tv_nsec = CDTIME_T_TO_NS ((cdt) % 1073741824); \
69 #define TIMESPEC_TO_CDTIME_T(ts) (TIME_T_TO_CDTIME_T ((ts)->tv_sec) \
70 + NS_TO_CDTIME_T ((ts)->tv_nsec))
72 cdtime_t cdtime (void);
74 /* format a cdtime_t value in ISO 8601 format:
75 * returns the number of characters written to the string (not including the
76 * terminating null byte or 0 on error; the function ensures that the string
77 * is null terminated */
78 size_t cdtime_to_iso8601 (char *s, size_t max, cdtime_t t);
80 #endif /* UTILS_TIME_H */
81 /* vim: set sw=2 sts=2 et : */