src/basic/time-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <inttypes.h>
   5 #include <stdbool.h>
   6 #include <stddef.h>
   7 #include <stdint.h>
   8 #include <stdio.h>
   9 #include <time.h>
  10
  11 typedef uint64_t usec_t;
  12 typedef uint64_t nsec_t;
  13
  14 #define PRI_NSEC PRIu64
  15 #define PRI_USEC PRIu64
  16 #define NSEC_FMT "%" PRI_NSEC
  17 #define USEC_FMT "%" PRI_USEC
  18
  19 #include "macro.h"
  20
  21 typedef struct dual_timestamp {
  22         usec_t realtime;
  23         usec_t monotonic;
  24 } dual_timestamp;
  25
  26 typedef struct triple_timestamp {
  27         usec_t realtime;
  28         usec_t monotonic;
  29         usec_t boottime;
  30 } triple_timestamp;
  31
  32 #define USEC_INFINITY ((usec_t) -1)
  33 #define NSEC_INFINITY ((nsec_t) -1)
  34
  35 #define MSEC_PER_SEC  1000ULL
  36 #define USEC_PER_SEC  ((usec_t) 1000000ULL)
  37 #define USEC_PER_MSEC ((usec_t) 1000ULL)
  38 #define NSEC_PER_SEC  ((nsec_t) 1000000000ULL)
  39 #define NSEC_PER_MSEC ((nsec_t) 1000000ULL)
  40 #define NSEC_PER_USEC ((nsec_t) 1000ULL)
  41
  42 #define USEC_PER_MINUTE ((usec_t) (60ULL*USEC_PER_SEC))
  43 #define NSEC_PER_MINUTE ((nsec_t) (60ULL*NSEC_PER_SEC))
  44 #define USEC_PER_HOUR ((usec_t) (60ULL*USEC_PER_MINUTE))
  45 #define NSEC_PER_HOUR ((nsec_t) (60ULL*NSEC_PER_MINUTE))
  46 #define USEC_PER_DAY ((usec_t) (24ULL*USEC_PER_HOUR))
  47 #define NSEC_PER_DAY ((nsec_t) (24ULL*NSEC_PER_HOUR))
  48 #define USEC_PER_WEEK ((usec_t) (7ULL*USEC_PER_DAY))
  49 #define NSEC_PER_WEEK ((nsec_t) (7ULL*NSEC_PER_DAY))
  50 #define USEC_PER_MONTH ((usec_t) (2629800ULL*USEC_PER_SEC))
  51 #define NSEC_PER_MONTH ((nsec_t) (2629800ULL*NSEC_PER_SEC))
  52 #define USEC_PER_YEAR ((usec_t) (31557600ULL*USEC_PER_SEC))
  53 #define NSEC_PER_YEAR ((nsec_t) (31557600ULL*NSEC_PER_SEC))
  54
  55 /* We assume a maximum timezone length of 6. TZNAME_MAX is not defined on Linux, but glibc internally initializes this
  56  * to 6. Let's rely on that. */
  57 #define FORMAT_TIMESTAMP_MAX (3+1+10+1+8+1+6+1+6+1)
  58 #define FORMAT_TIMESTAMP_WIDTH 28 /* when outputting, assume this width */
  59 #define FORMAT_TIMESTAMP_RELATIVE_MAX 256
  60 #define FORMAT_TIMESPAN_MAX 64
  61
  62 #define TIME_T_MAX (time_t)((UINTMAX_C(1) << ((sizeof(time_t) << 3) - 1)) - 1)
  63
  64 #define DUAL_TIMESTAMP_NULL ((struct dual_timestamp) {})
  65 #define TRIPLE_TIMESTAMP_NULL ((struct triple_timestamp) {})
  66
  67 usec_t now(clockid_t clock);
  68 nsec_t now_nsec(clockid_t clock);
  69
  70 dual_timestamp* dual_timestamp_get(dual_timestamp *ts);
  71 dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u);
  72 dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u);
  73 dual_timestamp* dual_timestamp_from_boottime_or_monotonic(dual_timestamp *ts, usec_t u);
  74
  75 triple_timestamp* triple_timestamp_get(triple_timestamp *ts);
  76 triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u);
  77
  78 #define DUAL_TIMESTAMP_HAS_CLOCK(clock)                               \
  79         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC)
  80
  81 #define TRIPLE_TIMESTAMP_HAS_CLOCK(clock)                               \
  82         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM)
  83
  84 static inline bool dual_timestamp_is_set(const dual_timestamp *ts) {
  85         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
  86                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY));
  87 }
  88
  89 static inline bool triple_timestamp_is_set(const triple_timestamp *ts) {
  90         return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
  91                 (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY) ||
  92                 (ts->boottime > 0 && ts->boottime != USEC_INFINITY));
  93 }
  94
  95 usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock);
  96
  97 usec_t timespec_load(const struct timespec *ts) _pure_;
  98 nsec_t timespec_load_nsec(const struct timespec *ts) _pure_;
  99 struct timespec *timespec_store(struct timespec *ts, usec_t u);
 100
 101 usec_t timeval_load(const struct timeval *tv) _pure_;
 102 struct timeval *timeval_store(struct timeval *tv, usec_t u);
 103
 104 char *format_timestamp(char *buf, size_t l, usec_t t);
 105 char *format_timestamp_utc(char *buf, size_t l, usec_t t);
 106 char *format_timestamp_us(char *buf, size_t l, usec_t t);
 107 char *format_timestamp_us_utc(char *buf, size_t l, usec_t t);
 108 char *format_timestamp_relative(char *buf, size_t l, usec_t t);
 109 char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy);
 110
 111 int parse_timestamp(const char *t, usec_t *usec);
 112
 113 int parse_sec(const char *t, usec_t *usec);
 114 int parse_sec_fix_0(const char *t, usec_t *usec);
 115 int parse_time(const char *t, usec_t *usec, usec_t default_unit);
 116 int parse_nsec(const char *t, nsec_t *nsec);
 117
 118 bool ntp_synced(void);
 119
 120 int get_timezones(char ***l);
 121 bool timezone_is_valid(const char *name, int log_level);
 122
 123 bool clock_boottime_supported(void);
 124 bool clock_supported(clockid_t clock);
 125 clockid_t clock_boottime_or_monotonic(void);
 126
 127 usec_t usec_shift_clock(usec_t, clockid_t from, clockid_t to);
 128
 129 int get_timezone(char **timezone);
 130
 131 time_t mktime_or_timegm(struct tm *tm, bool utc);
 132 struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);
 133
 134 unsigned long usec_to_jiffies(usec_t usec);
 135
 136 bool in_utc_timezone(void);
 137
 138 static inline usec_t usec_add(usec_t a, usec_t b) {
 139         usec_t c;
 140
 141         /* Adds two time values, and makes sure USEC_INFINITY as input results as USEC_INFINITY in output, and doesn't
 142          * overflow. */
 143
 144         c = a + b;
 145         if (c < a || c < b) /* overflow check */
 146                 return USEC_INFINITY;
 147
 148         return c;
 149 }
 150
 151 static inline usec_t usec_sub_unsigned(usec_t timestamp, usec_t delta) {
 152
 153         if (timestamp == USEC_INFINITY) /* Make sure infinity doesn't degrade */
 154                 return USEC_INFINITY;
 155         if (timestamp < delta)
 156                 return 0;
 157
 158         return timestamp - delta;
 159 }
 160
 161 static inline usec_t usec_sub_signed(usec_t timestamp, int64_t delta) {
 162         if (delta < 0)
 163                 return usec_add(timestamp, (usec_t) (-delta));
 164         else
 165                 return usec_sub_unsigned(timestamp, (usec_t) delta);
 166 }
 167
 168 #if SIZEOF_TIME_T == 8
 169 /* The last second we can format is 31. Dec 9999, 1s before midnight, because otherwise we'd enter 5 digit year
 170  * territory. However, since we want to stay away from this in all timezones we take one day off. */
 171 #define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 253402214399000000)
 172 #elif SIZEOF_TIME_T == 4
 173 /* With a 32bit time_t we can't go beyond 2038... */
 174 #define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 2147483647000000)
 175 #else
 176 #error "Yuck, time_t is neither 4 nor 8 bytes wide?"
 177 #endif
 178
 179 int time_change_fd(void);