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 /* We assume a maximum timezone length of 6. TZNAME_MAX is not defined on Linux, but glibc internally initializes this
  72  * to 6. Let's rely on that. */
  73 #define FORMAT_TIMESTAMP_MAX (3+1+10+1+8+1+6+1+6+1)
  74 #define FORMAT_TIMESTAMP_WIDTH 28 /* when outputting, assume this width */
  75 #define FORMAT_TIMESTAMP_RELATIVE_MAX 256
  76 #define FORMAT_TIMESPAN_MAX 64
  77
  78 #define TIME_T_MAX (time_t)((UINTMAX_C(1) << ((sizeof(time_t) << 3) - 1)) - 1)
  79
  80 #define DUAL_TIMESTAMP_NULL ((struct dual_timestamp) {})
  81 #define TRIPLE_TIMESTAMP_NULL ((struct triple_timestamp) {})
  82
  83 usec_t now(clockid_t clock);
  84 nsec_t now_nsec(clockid_t clock);
  85
  86 dual_timestamp* dual_timestamp_get(dual_timestamp *ts);
  87 dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u);
  88 dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u);
  89 dual_timestamp* dual_timestamp_from_boottime_or_monotonic(dual_timestamp *ts, usec_t u);
  90
  91 triple_timestamp* triple_timestamp_get(triple_timestamp *ts);
  92 triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u);
  93
  94 #define DUAL_TIMESTAMP_HAS_CLOCK(clock)                               \
  95         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC)
  96
  97 #define TRIPLE_TIMESTAMP_HAS_CLOCK(clock)                               \
  98         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM)
  99
 100 static inline bool dual_timestamp_is_set(dual_timestamp *ts) {
 101         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
 102                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY));
 103 }
 104
 105 static inline bool triple_timestamp_is_set(triple_timestamp *ts) {
 106         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
 107                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY) ||
 108                 (ts->boottime > 0 && ts->boottime != USEC_INFINITY));
 109 }
 110
 111 usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock);
 112
 113 usec_t timespec_load(const struct timespec *ts) _pure_;
 114 struct timespec *timespec_store(struct timespec *ts, usec_t u);
 115
 116 usec_t timeval_load(const struct timeval *tv) _pure_;
 117 struct timeval *timeval_store(struct timeval *tv, usec_t u);
 118
 119 char *format_timestamp(char *buf, size_t l, usec_t t);
 120 char *format_timestamp_utc(char *buf, size_t l, usec_t t);
 121 char *format_timestamp_us(char *buf, size_t l, usec_t t);
 122 char *format_timestamp_us_utc(char *buf, size_t l, usec_t t);
 123 char *format_timestamp_relative(char *buf, size_t l, usec_t t);
 124 char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy);
 125
 126 void dual_timestamp_serialize(FILE *f, const char *name, dual_timestamp *t);
 127 int dual_timestamp_deserialize(const char *value, dual_timestamp *t);
 128 int timestamp_deserialize(const char *value, usec_t *timestamp);
 129
 130 int parse_timestamp(const char *t, usec_t *usec);
 131
 132 int parse_sec(const char *t, usec_t *usec);
 133 int parse_time(const char *t, usec_t *usec, usec_t default_unit);
 134 int parse_nsec(const char *t, nsec_t *nsec);
 135
 136 bool ntp_synced(void);
 137
 138 int get_timezones(char ***l);
 139 bool timezone_is_valid(const char *name);
 140
 141 bool clock_boottime_supported(void);
 142 bool clock_supported(clockid_t clock);
 143 clockid_t clock_boottime_or_monotonic(void);
 144
 145 #define xstrftime(buf, fmt, tm) \
 146         assert_message_se(strftime(buf, ELEMENTSOF(buf), fmt, tm) > 0, \
 147                           "xstrftime: " #buf "[] must be big enough")
 148
 149 int get_timezone(char **timezone);
 150
 151 time_t mktime_or_timegm(struct tm *tm, bool utc);
 152 struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);
 153
 154 unsigned long usec_to_jiffies(usec_t usec);
 155
 156 static inline usec_t usec_add(usec_t a, usec_t b) {
 157         usec_t c;
 158
 159         /* Adds two time values, and makes sure USEC_INFINITY as input results as USEC_INFINITY in output, and doesn't
 160          * overflow. */
 161
 162         c = a + b;
 163         if (c < a || c < b) /* overflow check */
 164                 return USEC_INFINITY;
 165
 166         return c;
 167 }
 168
 169 static inline usec_t usec_sub(usec_t timestamp, int64_t delta) {
 170         if (delta < 0)
 171                 return usec_add(timestamp, (usec_t) (-delta));
 172
 173         if (timestamp == USEC_INFINITY) /* Make sure infinity doesn't degrade */
 174                 return USEC_INFINITY;
 175
 176         if (timestamp < (usec_t) delta)
 177                 return 0;
 178
 179         return timestamp - delta;
 180 }