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 PRI_NSEC PRIu64
  33 #define PRI_USEC PRIu64
  34 #define NSEC_FMT "%" PRI_NSEC
  35 #define USEC_FMT "%" PRI_USEC
  36
  37 #include "macro.h"
  38
  39 typedef struct dual_timestamp {
  40         usec_t realtime;
  41         usec_t monotonic;
  42 } dual_timestamp;
  43
  44 typedef struct triple_timestamp {
  45         usec_t realtime;
  46         usec_t monotonic;
  47         usec_t boottime;
  48 } triple_timestamp;
  49
  50 #define USEC_INFINITY ((usec_t) -1)
  51 #define NSEC_INFINITY ((nsec_t) -1)
  52
  53 #define MSEC_PER_SEC  1000ULL
  54 #define USEC_PER_SEC  ((usec_t) 1000000ULL)
  55 #define USEC_PER_MSEC ((usec_t) 1000ULL)
  56 #define NSEC_PER_SEC  ((nsec_t) 1000000000ULL)
  57 #define NSEC_PER_MSEC ((nsec_t) 1000000ULL)
  58 #define NSEC_PER_USEC ((nsec_t) 1000ULL)
  59
  60 #define USEC_PER_MINUTE ((usec_t) (60ULL*USEC_PER_SEC))
  61 #define NSEC_PER_MINUTE ((nsec_t) (60ULL*NSEC_PER_SEC))
  62 #define USEC_PER_HOUR ((usec_t) (60ULL*USEC_PER_MINUTE))
  63 #define NSEC_PER_HOUR ((nsec_t) (60ULL*NSEC_PER_MINUTE))
  64 #define USEC_PER_DAY ((usec_t) (24ULL*USEC_PER_HOUR))
  65 #define NSEC_PER_DAY ((nsec_t) (24ULL*NSEC_PER_HOUR))
  66 #define USEC_PER_WEEK ((usec_t) (7ULL*USEC_PER_DAY))
  67 #define NSEC_PER_WEEK ((nsec_t) (7ULL*NSEC_PER_DAY))
  68 #define USEC_PER_MONTH ((usec_t) (2629800ULL*USEC_PER_SEC))
  69 #define NSEC_PER_MONTH ((nsec_t) (2629800ULL*NSEC_PER_SEC))
  70 #define USEC_PER_YEAR ((usec_t) (31557600ULL*USEC_PER_SEC))
  71 #define NSEC_PER_YEAR ((nsec_t) (31557600ULL*NSEC_PER_SEC))
  72
  73 /* We assume a maximum timezone length of 6. TZNAME_MAX is not defined on Linux, but glibc internally initializes this
  74  * to 6. Let's rely on that. */
  75 #define FORMAT_TIMESTAMP_MAX (3+1+10+1+8+1+6+1+6+1)
  76 #define FORMAT_TIMESTAMP_WIDTH 28 /* when outputting, assume this width */
  77 #define FORMAT_TIMESTAMP_RELATIVE_MAX 256
  78 #define FORMAT_TIMESPAN_MAX 64
  79
  80 #define TIME_T_MAX (time_t)((UINTMAX_C(1) << ((sizeof(time_t) << 3) - 1)) - 1)
  81
  82 #define DUAL_TIMESTAMP_NULL ((struct dual_timestamp) {})
  83 #define TRIPLE_TIMESTAMP_NULL ((struct triple_timestamp) {})
  84
  85 usec_t now(clockid_t clock);
  86 nsec_t now_nsec(clockid_t clock);
  87
  88 dual_timestamp* dual_timestamp_get(dual_timestamp *ts);
  89 dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u);
  90 dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u);
  91 dual_timestamp* dual_timestamp_from_boottime_or_monotonic(dual_timestamp *ts, usec_t u);
  92
  93 triple_timestamp* triple_timestamp_get(triple_timestamp *ts);
  94 triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u);
  95
  96 #define DUAL_TIMESTAMP_HAS_CLOCK(clock)                               \
  97         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC)
  98
  99 #define TRIPLE_TIMESTAMP_HAS_CLOCK(clock)                               \
 100         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM)
 101
 102 static inline bool dual_timestamp_is_set(dual_timestamp *ts) {
 103         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
 104                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY));
 105 }
 106
 107 static inline bool triple_timestamp_is_set(triple_timestamp *ts) {
 108         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
 109                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY) ||
 110                 (ts->boottime > 0 && ts->boottime != USEC_INFINITY));
 111 }
 112
 113 usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock);
 114
 115 usec_t timespec_load(const struct timespec *ts) _pure_;
 116 nsec_t timespec_load_nsec(const struct timespec *ts) _pure_;
 117 struct timespec *timespec_store(struct timespec *ts, usec_t u);
 118
 119 usec_t timeval_load(const struct timeval *tv) _pure_;
 120 struct timeval *timeval_store(struct timeval *tv, usec_t u);
 121
 122 char *format_timestamp(char *buf, size_t l, usec_t t);
 123 char *format_timestamp_utc(char *buf, size_t l, usec_t t);
 124 char *format_timestamp_us(char *buf, size_t l, usec_t t);
 125 char *format_timestamp_us_utc(char *buf, size_t l, usec_t t);
 126 char *format_timestamp_relative(char *buf, size_t l, usec_t t);
 127 char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy);
 128
 129 void dual_timestamp_serialize(FILE *f, const char *name, dual_timestamp *t);
 130 int dual_timestamp_deserialize(const char *value, dual_timestamp *t);
 131 int timestamp_deserialize(const char *value, usec_t *timestamp);
 132
 133 int parse_timestamp(const char *t, usec_t *usec);
 134
 135 int parse_sec(const char *t, usec_t *usec);
 136 int parse_sec_fix_0(const char *t, usec_t *usec);
 137 int parse_time(const char *t, usec_t *usec, usec_t default_unit);
 138 int parse_nsec(const char *t, nsec_t *nsec);
 139
 140 bool ntp_synced(void);
 141
 142 int get_timezones(char ***l);
 143 bool timezone_is_valid(const char *name);
 144
 145 bool clock_boottime_supported(void);
 146 bool clock_supported(clockid_t clock);
 147 clockid_t clock_boottime_or_monotonic(void);
 148
 149 usec_t usec_shift_clock(usec_t, clockid_t from, clockid_t to);
 150
 151 #define xstrftime(buf, fmt, tm) \
 152         assert_message_se(strftime(buf, ELEMENTSOF(buf), fmt, tm) > 0, \
 153                           "xstrftime: " #buf "[] must be big enough")
 154
 155 int get_timezone(char **timezone);
 156
 157 time_t mktime_or_timegm(struct tm *tm, bool utc);
 158 struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);
 159
 160 unsigned long usec_to_jiffies(usec_t usec);
 161
 162 static inline usec_t usec_add(usec_t a, usec_t b) {
 163         usec_t c;
 164
 165         /* Adds two time values, and makes sure USEC_INFINITY as input results as USEC_INFINITY in output, and doesn't
 166          * overflow. */
 167
 168         c = a + b;
 169         if (c < a || c < b) /* overflow check */
 170                 return USEC_INFINITY;
 171
 172         return c;
 173 }
 174
 175 static inline usec_t usec_sub_unsigned(usec_t timestamp, usec_t delta) {
 176
 177         if (timestamp == USEC_INFINITY) /* Make sure infinity doesn't degrade */
 178                 return USEC_INFINITY;
 179         if (timestamp < delta)
 180                 return 0;
 181
 182         return timestamp - delta;
 183 }
 184
 185 static inline usec_t usec_sub_signed(usec_t timestamp, int64_t delta) {
 186         if (delta < 0)
 187                 return usec_add(timestamp, (usec_t) (-delta));
 188         else
 189                 return usec_sub_unsigned(timestamp, (usec_t) delta);
 190 }
 191
 192 #if SIZEOF_TIME_T == 8
 193 /* The last second we can format is 31. Dec 9999, 1s before midnight, because otherwise we'd enter 5 digit year
 194  * territory. However, since we want to stay away from this in all timezones we take one day off. */
 195 #define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 253402214399000000)
 196 #elif SIZEOF_TIME_T == 4
 197 /* With a 32bit time_t we can't go beyond 2038... */
 198 #define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 2147483647000000)
 199 #else
 200 #error "Yuck, time_t is neither 4 not 8 bytes wide?"
 201 #endif