src/basic/time-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2010 Lennart Poettering
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21 ***/
  22
  23 #include <inttypes.h>
  24 #include <stdbool.h>
  25 #include <stddef.h>
  26 #include <stdint.h>
  27 #include <stdio.h>
  28 #include <time.h>
  29
  30 typedef uint64_t usec_t;
  31 typedef uint64_t nsec_t;
  32
  33 #define PRI_NSEC PRIu64
  34 #define PRI_USEC PRIu64
  35 #define NSEC_FMT "%" PRI_NSEC
  36 #define USEC_FMT "%" PRI_USEC
  37
  38 #include "macro.h"
  39
  40 typedef struct dual_timestamp {
  41         usec_t realtime;
  42         usec_t monotonic;
  43 } dual_timestamp;
  44
  45 typedef struct triple_timestamp {
  46         usec_t realtime;
  47         usec_t monotonic;
  48         usec_t boottime;
  49 } triple_timestamp;
  50
  51 #define USEC_INFINITY ((usec_t) -1)
  52 #define NSEC_INFINITY ((nsec_t) -1)
  53
  54 #define MSEC_PER_SEC  1000ULL
  55 #define USEC_PER_SEC  ((usec_t) 1000000ULL)
  56 #define USEC_PER_MSEC ((usec_t) 1000ULL)
  57 #define NSEC_PER_SEC  ((nsec_t) 1000000000ULL)
  58 #define NSEC_PER_MSEC ((nsec_t) 1000000ULL)
  59 #define NSEC_PER_USEC ((nsec_t) 1000ULL)
  60
  61 #define USEC_PER_MINUTE ((usec_t) (60ULL*USEC_PER_SEC))
  62 #define NSEC_PER_MINUTE ((nsec_t) (60ULL*NSEC_PER_SEC))
  63 #define USEC_PER_HOUR ((usec_t) (60ULL*USEC_PER_MINUTE))
  64 #define NSEC_PER_HOUR ((nsec_t) (60ULL*NSEC_PER_MINUTE))
  65 #define USEC_PER_DAY ((usec_t) (24ULL*USEC_PER_HOUR))
  66 #define NSEC_PER_DAY ((nsec_t) (24ULL*NSEC_PER_HOUR))
  67 #define USEC_PER_WEEK ((usec_t) (7ULL*USEC_PER_DAY))
  68 #define NSEC_PER_WEEK ((nsec_t) (7ULL*NSEC_PER_DAY))
  69 #define USEC_PER_MONTH ((usec_t) (2629800ULL*USEC_PER_SEC))
  70 #define NSEC_PER_MONTH ((nsec_t) (2629800ULL*NSEC_PER_SEC))
  71 #define USEC_PER_YEAR ((usec_t) (31557600ULL*USEC_PER_SEC))
  72 #define NSEC_PER_YEAR ((nsec_t) (31557600ULL*NSEC_PER_SEC))
  73
  74 /* We assume a maximum timezone length of 6. TZNAME_MAX is not defined on Linux, but glibc internally initializes this
  75  * to 6. Let's rely on that. */
  76 #define FORMAT_TIMESTAMP_MAX (3+1+10+1+8+1+6+1+6+1)
  77 #define FORMAT_TIMESTAMP_WIDTH 28 /* when outputting, assume this width */
  78 #define FORMAT_TIMESTAMP_RELATIVE_MAX 256
  79 #define FORMAT_TIMESPAN_MAX 64
  80
  81 #define TIME_T_MAX (time_t)((UINTMAX_C(1) << ((sizeof(time_t) << 3) - 1)) - 1)
  82
  83 #define DUAL_TIMESTAMP_NULL ((struct dual_timestamp) {})
  84 #define TRIPLE_TIMESTAMP_NULL ((struct triple_timestamp) {})
  85
  86 usec_t now(clockid_t clock);
  87 nsec_t now_nsec(clockid_t clock);
  88
  89 dual_timestamp* dual_timestamp_get(dual_timestamp *ts);
  90 dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u);
  91 dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u);
  92 dual_timestamp* dual_timestamp_from_boottime_or_monotonic(dual_timestamp *ts, usec_t u);
  93
  94 triple_timestamp* triple_timestamp_get(triple_timestamp *ts);
  95 triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u);
  96
  97 #define DUAL_TIMESTAMP_HAS_CLOCK(clock)                               \
  98         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC)
  99
 100 #define TRIPLE_TIMESTAMP_HAS_CLOCK(clock)                               \
 101         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM)
 102
 103 static inline bool dual_timestamp_is_set(dual_timestamp *ts) {
 104         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
 105                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY));
 106 }
 107
 108 static inline bool triple_timestamp_is_set(triple_timestamp *ts) {
 109         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
 110                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY) ||
 111                 (ts->boottime > 0 && ts->boottime != USEC_INFINITY));
 112 }
 113
 114 usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock);
 115
 116 usec_t timespec_load(const struct timespec *ts) _pure_;
 117 nsec_t timespec_load_nsec(const struct timespec *ts) _pure_;
 118 struct timespec *timespec_store(struct timespec *ts, usec_t u);
 119
 120 usec_t timeval_load(const struct timeval *tv) _pure_;
 121 struct timeval *timeval_store(struct timeval *tv, usec_t u);
 122
 123 char *format_timestamp(char *buf, size_t l, usec_t t);
 124 char *format_timestamp_utc(char *buf, size_t l, usec_t t);
 125 char *format_timestamp_us(char *buf, size_t l, usec_t t);
 126 char *format_timestamp_us_utc(char *buf, size_t l, usec_t t);
 127 char *format_timestamp_relative(char *buf, size_t l, usec_t t);
 128 char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy);
 129
 130 void dual_timestamp_serialize(FILE *f, const char *name, dual_timestamp *t);
 131 int dual_timestamp_deserialize(const char *value, dual_timestamp *t);
 132 int timestamp_deserialize(const char *value, usec_t *timestamp);
 133
 134 int parse_timestamp(const char *t, usec_t *usec);
 135
 136 int parse_sec(const char *t, usec_t *usec);
 137 int parse_sec_fix_0(const char *t, usec_t *usec);
 138 int parse_time(const char *t, usec_t *usec, usec_t default_unit);
 139 int parse_nsec(const char *t, nsec_t *nsec);
 140
 141 bool ntp_synced(void);
 142
 143 int get_timezones(char ***l);
 144 bool timezone_is_valid(const char *name);
 145
 146 bool clock_boottime_supported(void);
 147 bool clock_supported(clockid_t clock);
 148 clockid_t clock_boottime_or_monotonic(void);
 149
 150 usec_t usec_shift_clock(usec_t, clockid_t from, clockid_t to);
 151
 152 int get_timezone(char **timezone);
 153
 154 time_t mktime_or_timegm(struct tm *tm, bool utc);
 155 struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);
 156
 157 unsigned long usec_to_jiffies(usec_t usec);
 158
 159 static inline usec_t usec_add(usec_t a, usec_t b) {
 160         usec_t c;
 161
 162         /* Adds two time values, and makes sure USEC_INFINITY as input results as USEC_INFINITY in output, and doesn't
 163          * overflow. */
 164
 165         c = a + b;
 166         if (c < a || c < b) /* overflow check */
 167                 return USEC_INFINITY;
 168
 169         return c;
 170 }
 171
 172 static inline usec_t usec_sub_unsigned(usec_t timestamp, usec_t delta) {
 173
 174         if (timestamp == USEC_INFINITY) /* Make sure infinity doesn't degrade */
 175                 return USEC_INFINITY;
 176         if (timestamp < delta)
 177                 return 0;
 178
 179         return timestamp - delta;
 180 }
 181
 182 static inline usec_t usec_sub_signed(usec_t timestamp, int64_t delta) {
 183         if (delta < 0)
 184                 return usec_add(timestamp, (usec_t) (-delta));
 185         else
 186                 return usec_sub_unsigned(timestamp, (usec_t) delta);
 187 }
 188
 189 #if SIZEOF_TIME_T == 8
 190 /* The last second we can format is 31. Dec 9999, 1s before midnight, because otherwise we'd enter 5 digit year
 191  * territory. However, since we want to stay away from this in all timezones we take one day off. */
 192 #define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 253402214399000000)
 193 #elif SIZEOF_TIME_T == 4
 194 /* With a 32bit time_t we can't go beyond 2038... */
 195 #define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 2147483647000000)
 196 #else
 197 #error "Yuck, time_t is neither 4 not 8 bytes wide?"
 198 #endif