src/basic/time-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   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 typedef enum TimestampStyle {
  33         TIMESTAMP_PRETTY,
  34         TIMESTAMP_US,
  35         TIMESTAMP_UTC,
  36         TIMESTAMP_US_UTC,
  37         _TIMESTAMP_STYLE_MAX,
  38         _TIMESTAMP_STYLE_INVALID = -EINVAL,
  39 } TimestampStyle;
  40
  41 #define USEC_INFINITY ((usec_t) UINT64_MAX)
  42 #define NSEC_INFINITY ((nsec_t) UINT64_MAX)
  43
  44 #define MSEC_PER_SEC  1000ULL
  45 #define USEC_PER_SEC  ((usec_t) 1000000ULL)
  46 #define USEC_PER_MSEC ((usec_t) 1000ULL)
  47 #define NSEC_PER_SEC  ((nsec_t) 1000000000ULL)
  48 #define NSEC_PER_MSEC ((nsec_t) 1000000ULL)
  49 #define NSEC_PER_USEC ((nsec_t) 1000ULL)
  50
  51 #define USEC_PER_MINUTE ((usec_t) (60ULL*USEC_PER_SEC))
  52 #define NSEC_PER_MINUTE ((nsec_t) (60ULL*NSEC_PER_SEC))
  53 #define USEC_PER_HOUR ((usec_t) (60ULL*USEC_PER_MINUTE))
  54 #define NSEC_PER_HOUR ((nsec_t) (60ULL*NSEC_PER_MINUTE))
  55 #define USEC_PER_DAY ((usec_t) (24ULL*USEC_PER_HOUR))
  56 #define NSEC_PER_DAY ((nsec_t) (24ULL*NSEC_PER_HOUR))
  57 #define USEC_PER_WEEK ((usec_t) (7ULL*USEC_PER_DAY))
  58 #define NSEC_PER_WEEK ((nsec_t) (7ULL*NSEC_PER_DAY))
  59 #define USEC_PER_MONTH ((usec_t) (2629800ULL*USEC_PER_SEC))
  60 #define NSEC_PER_MONTH ((nsec_t) (2629800ULL*NSEC_PER_SEC))
  61 #define USEC_PER_YEAR ((usec_t) (31557600ULL*USEC_PER_SEC))
  62 #define NSEC_PER_YEAR ((nsec_t) (31557600ULL*NSEC_PER_SEC))
  63
  64 /* We assume a maximum timezone length of 6. TZNAME_MAX is not defined on Linux, but glibc internally initializes this
  65  * to 6. Let's rely on that. */
  66 #define FORMAT_TIMESTAMP_MAX (3U+1U+10U+1U+8U+1U+6U+1U+6U+1U)
  67 #define FORMAT_TIMESTAMP_WIDTH 28U /* when outputting, assume this width */
  68 #define FORMAT_TIMESTAMP_RELATIVE_MAX 256U
  69 #define FORMAT_TIMESPAN_MAX 64U
  70
  71 #define TIME_T_MAX (time_t)((UINTMAX_C(1) << ((sizeof(time_t) << 3) - 1)) - 1)
  72
  73 #define DUAL_TIMESTAMP_NULL ((struct dual_timestamp) {})
  74 #define TRIPLE_TIMESTAMP_NULL ((struct triple_timestamp) {})
  75
  76 usec_t now(clockid_t clock);
  77 nsec_t now_nsec(clockid_t clock);
  78
  79 usec_t map_clock_usec(usec_t from, clockid_t from_clock, clockid_t to_clock);
  80
  81 dual_timestamp* dual_timestamp_get(dual_timestamp *ts);
  82 dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u);
  83 dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u);
  84 dual_timestamp* dual_timestamp_from_boottime_or_monotonic(dual_timestamp *ts, usec_t u);
  85
  86 triple_timestamp* triple_timestamp_get(triple_timestamp *ts);
  87 triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u);
  88
  89 #define DUAL_TIMESTAMP_HAS_CLOCK(clock)                               \
  90         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC)
  91
  92 #define TRIPLE_TIMESTAMP_HAS_CLOCK(clock)                               \
  93         IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM)
  94
  95 static inline bool timestamp_is_set(usec_t timestamp) {
  96         return timestamp > 0 && timestamp != USEC_INFINITY;
  97 }
  98
  99 static inline bool dual_timestamp_is_set(const dual_timestamp *ts) {
 100         return timestamp_is_set(ts->realtime) ||
 101                timestamp_is_set(ts->monotonic);
 102 }
 103
 104 static inline bool triple_timestamp_is_set(const triple_timestamp *ts) {
 105         return timestamp_is_set(ts->realtime) ||
 106                timestamp_is_set(ts->monotonic) ||
 107                timestamp_is_set(ts->boottime);
 108 }
 109
 110 usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock);
 111
 112 usec_t timespec_load(const struct timespec *ts) _pure_;
 113 nsec_t timespec_load_nsec(const struct timespec *ts) _pure_;
 114 struct timespec* timespec_store(struct timespec *ts, usec_t u);
 115 struct timespec* timespec_store_nsec(struct timespec *ts, nsec_t n);
 116
 117 usec_t timeval_load(const struct timeval *tv) _pure_;
 118 struct timeval* timeval_store(struct timeval *tv, usec_t u);
 119
 120 char* format_timestamp_style(char *buf, size_t l, usec_t t, TimestampStyle style);
 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 static inline char* format_timestamp(char *buf, size_t l, usec_t t) {
 125         return format_timestamp_style(buf, l, t, TIMESTAMP_PRETTY);
 126 }
 127
 128 /* Note: the lifetime of the compound literal is the immediately surrounding block,
 129  * see C11 §6.5.2.5, and
 130  * https://stackoverflow.com/questions/34880638/compound-literal-lifetime-and-if-blocks */
 131 #define FORMAT_TIMESTAMP(t) format_timestamp((char[FORMAT_TIMESTAMP_MAX]){}, FORMAT_TIMESTAMP_MAX, t)
 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_sec_def_infinity(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 int get_timezones(char ***l);
 142 int verify_timezone(const char *name, int log_level);
 143 static inline bool timezone_is_valid(const char *name, int log_level) {
 144         return verify_timezone(name, log_level) >= 0;
 145 }
 146
 147 bool clock_boottime_supported(void);
 148 bool clock_supported(clockid_t clock);
 149 clockid_t clock_boottime_or_monotonic(void);
 150
 151 usec_t usec_shift_clock(usec_t, clockid_t from, clockid_t to);
 152
 153 int get_timezone(char **timezone);
 154
 155 time_t mktime_or_timegm(struct tm *tm, bool utc);
 156 struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);
 157
 158 uint32_t usec_to_jiffies(usec_t usec);
 159 usec_t jiffies_to_usec(uint32_t jiffies);
 160
 161 bool in_utc_timezone(void);
 162
 163 static inline usec_t usec_add(usec_t a, usec_t b) {
 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         if (a > USEC_INFINITY - b) /* overflow check */
 169                 return USEC_INFINITY;
 170
 171         return a + b;
 172 }
 173
 174 static inline usec_t usec_sub_unsigned(usec_t timestamp, usec_t delta) {
 175
 176         if (timestamp == USEC_INFINITY) /* Make sure infinity doesn't degrade */
 177                 return USEC_INFINITY;
 178         if (timestamp < delta)
 179                 return 0;
 180
 181         return timestamp - delta;
 182 }
 183
 184 static inline usec_t usec_sub_signed(usec_t timestamp, int64_t delta) {
 185         if (delta < 0)
 186                 return usec_add(timestamp, (usec_t) (-delta));
 187         else
 188                 return usec_sub_unsigned(timestamp, (usec_t) delta);
 189 }
 190
 191 #if SIZEOF_TIME_T == 8
 192 /* The last second we can format is 31. Dec 9999, 1s before midnight, because otherwise we'd enter 5 digit year
 193  * territory. However, since we want to stay away from this in all timezones we take one day off. */
 194 #define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 253402214399000000)
 195 #elif SIZEOF_TIME_T == 4
 196 /* With a 32bit time_t we can't go beyond 2038... */
 197 #define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 2147483647000000)
 198 #else
 199 #error "Yuck, time_t is neither 4 nor 8 bytes wide?"
 200 #endif
 201
 202 int time_change_fd(void);
 203
 204 const char* timestamp_style_to_string(TimestampStyle t) _const_;
 205 TimestampStyle timestamp_style_from_string(const char *s) _pure_;