src/basic/time-util.h

   1 #pragma once
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <inttypes.h>
  23 #include <stdbool.h>
  24 #include <stddef.h>
  25 #include <stdint.h>
  26 #include <stdio.h>
  27 #include <time.h>
  28
  29 typedef uint64_t usec_t;
  30 typedef uint64_t nsec_t;
  31
  32 #define NSEC_FMT "%" PRIu64
  33 #define USEC_FMT "%" PRIu64
  34
  35 #include "macro.h"
  36
  37 typedef struct dual_timestamp {
  38         usec_t realtime;
  39         usec_t monotonic;
  40 } dual_timestamp;
  41
  42 typedef struct triple_timestamp {
  43         usec_t realtime;
  44         usec_t monotonic;
  45         usec_t boottime;
  46 } triple_timestamp;
  47
  48 #define USEC_INFINITY ((usec_t) -1)
  49 #define NSEC_INFINITY ((nsec_t) -1)
  50
  51 #define MSEC_PER_SEC  1000ULL
  52 #define USEC_PER_SEC  ((usec_t) 1000000ULL)
  53 #define USEC_PER_MSEC ((usec_t) 1000ULL)
  54 #define NSEC_PER_SEC  ((nsec_t) 1000000000ULL)
  55 #define NSEC_PER_MSEC ((nsec_t) 1000000ULL)
  56 #define NSEC_PER_USEC ((nsec_t) 1000ULL)
  57
  58 #define USEC_PER_MINUTE ((usec_t) (60ULL*USEC_PER_SEC))
  59 #define NSEC_PER_MINUTE ((nsec_t) (60ULL*NSEC_PER_SEC))
  60 #define USEC_PER_HOUR ((usec_t) (60ULL*USEC_PER_MINUTE))
  61 #define NSEC_PER_HOUR ((nsec_t) (60ULL*NSEC_PER_MINUTE))
  62 #define USEC_PER_DAY ((usec_t) (24ULL*USEC_PER_HOUR))
  63 #define NSEC_PER_DAY ((nsec_t) (24ULL*NSEC_PER_HOUR))
  64 #define USEC_PER_WEEK ((usec_t) (7ULL*USEC_PER_DAY))
  65 #define NSEC_PER_WEEK ((nsec_t) (7ULL*NSEC_PER_DAY))
  66 #define USEC_PER_MONTH ((usec_t) (2629800ULL*USEC_PER_SEC))
  67 #define NSEC_PER_MONTH ((nsec_t) (2629800ULL*NSEC_PER_SEC))
  68 #define USEC_PER_YEAR ((usec_t) (31557600ULL*USEC_PER_SEC))
  69 #define NSEC_PER_YEAR ((nsec_t) (31557600ULL*NSEC_PER_SEC))
  70
  71 #define FORMAT_TIMESTAMP_MAX ((4*4+1)+11+9+4+1) /* weekdays can be unicode */
  72 #define FORMAT_TIMESTAMP_WIDTH 28 /* when outputting, assume this width */
  73 #define FORMAT_TIMESTAMP_RELATIVE_MAX 256
  74 #define FORMAT_TIMESPAN_MAX 64
  75
  76 #define TIME_T_MAX (time_t)((UINTMAX_C(1) << ((sizeof(time_t) << 3) - 1)) - 1)
  77
  78 #define DUAL_TIMESTAMP_NULL ((struct dual_timestamp) {})
  79 #define TRIPLE_TIMESTAMP_NULL ((struct triple_timestamp) {})
  80
  81 usec_t now(clockid_t clock);
  82 nsec_t now_nsec(clockid_t clock);
  83
  84 dual_timestamp* dual_timestamp_get(dual_timestamp *ts);
  85 dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u);
  86 dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u);
  87 dual_timestamp* dual_timestamp_from_boottime_or_monotonic(dual_timestamp *ts, usec_t u);
  88
  89 triple_timestamp* triple_timestamp_get(triple_timestamp *ts);
  90 triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u);
  91
  92 #define DUAL_TIMESTAMP_HAS_CLOCK(clock)                               \
  93         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC)
  94
  95 #define TRIPLE_TIMESTAMP_HAS_CLOCK(clock)                               \
  96         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM)
  97
  98 static inline bool dual_timestamp_is_set(dual_timestamp *ts) {
  99         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
 100                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY));
 101 }
 102
 103 static inline bool triple_timestamp_is_set(triple_timestamp *ts) {
 104         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
 105                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY) ||
 106                 (ts->boottime > 0 && ts->boottime != USEC_INFINITY));
 107 }
 108
 109 usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock);
 110
 111 usec_t timespec_load(const struct timespec *ts) _pure_;
 112 struct timespec *timespec_store(struct timespec *ts, usec_t u);
 113
 114 usec_t timeval_load(const struct timeval *tv) _pure_;
 115 struct timeval *timeval_store(struct timeval *tv, usec_t u);
 116
 117 char *format_timestamp(char *buf, size_t l, usec_t t);
 118 char *format_timestamp_utc(char *buf, size_t l, usec_t t);
 119 char *format_timestamp_us(char *buf, size_t l, usec_t t);
 120 char *format_timestamp_us_utc(char *buf, size_t l, usec_t t);
 121 char *format_timestamp_relative(char *buf, size_t l, usec_t t);
 122 char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy);
 123
 124 void dual_timestamp_serialize(FILE *f, const char *name, dual_timestamp *t);
 125 int dual_timestamp_deserialize(const char *value, dual_timestamp *t);
 126 int timestamp_deserialize(const char *value, usec_t *timestamp);
 127
 128 int parse_timestamp(const char *t, usec_t *usec);
 129
 130 int parse_sec(const char *t, usec_t *usec);
 131 int parse_time(const char *t, usec_t *usec, usec_t default_unit);
 132 int parse_nsec(const char *t, nsec_t *nsec);
 133
 134 bool ntp_synced(void);
 135
 136 int get_timezones(char ***l);
 137 bool timezone_is_valid(const char *name);
 138
 139 bool clock_boottime_supported(void);
 140 bool clock_supported(clockid_t clock);
 141 clockid_t clock_boottime_or_monotonic(void);
 142
 143 #define xstrftime(buf, fmt, tm) \
 144         assert_message_se(strftime(buf, ELEMENTSOF(buf), fmt, tm) > 0, \
 145                           "xstrftime: " #buf "[] must be big enough")
 146
 147 int get_timezone(char **timezone);
 148
 149 time_t mktime_or_timegm(struct tm *tm, bool utc);
 150 struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);
 151
 152 unsigned long usec_to_jiffies(usec_t usec);
 153
 154 static inline usec_t usec_add(usec_t a, usec_t b) {
 155         usec_t c;
 156
 157         /* Adds two time values, and makes sure USEC_INFINITY as input results as USEC_INFINITY in output, and doesn't
 158          * overflow. */
 159
 160         c = a + b;
 161         if (c < a || c < b) /* overflow check */
 162                 return USEC_INFINITY;
 163
 164         return c;
 165 }
 166
 167 static inline usec_t usec_sub(usec_t timestamp, int64_t delta) {
 168         if (delta < 0)
 169                 return usec_add(timestamp, (usec_t) (-delta));
 170
 171         if (timestamp == USEC_INFINITY) /* Make sure infinity doesn't degrade */
 172                 return USEC_INFINITY;
 173
 174         if (timestamp < (usec_t) delta)
 175                 return 0;
 176
 177         return timestamp - delta;
 178 }