Files
systemd/src/basic/time-util.h
Yu Watanabe c876cbdd19 time-util: define TIMESPEC_OMIT
Follow-up for 34c3d57474.
2024-05-10 10:11:06 +09:00

252 lines
10 KiB
C

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once
#include <inttypes.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <time.h>
typedef uint64_t usec_t;
typedef uint64_t nsec_t;
#define PRI_NSEC PRIu64
#define PRI_USEC PRIu64
#define NSEC_FMT "%" PRI_NSEC
#define USEC_FMT "%" PRI_USEC
#include "macro.h"
typedef struct dual_timestamp {
usec_t realtime;
usec_t monotonic;
} dual_timestamp;
typedef struct triple_timestamp {
usec_t realtime;
usec_t monotonic;
usec_t boottime;
} triple_timestamp;
typedef enum TimestampStyle {
TIMESTAMP_PRETTY,
TIMESTAMP_US,
TIMESTAMP_UTC,
TIMESTAMP_US_UTC,
TIMESTAMP_UNIX,
TIMESTAMP_DATE,
_TIMESTAMP_STYLE_MAX,
_TIMESTAMP_STYLE_INVALID = -EINVAL,
} TimestampStyle;
#define USEC_INFINITY ((usec_t) UINT64_MAX)
#define NSEC_INFINITY ((nsec_t) UINT64_MAX)
#define MSEC_PER_SEC 1000ULL
#define USEC_PER_SEC ((usec_t) 1000000ULL)
#define USEC_PER_MSEC ((usec_t) 1000ULL)
#define NSEC_PER_SEC ((nsec_t) 1000000000ULL)
#define NSEC_PER_MSEC ((nsec_t) 1000000ULL)
#define NSEC_PER_USEC ((nsec_t) 1000ULL)
#define USEC_PER_MINUTE ((usec_t) (60ULL*USEC_PER_SEC))
#define NSEC_PER_MINUTE ((nsec_t) (60ULL*NSEC_PER_SEC))
#define USEC_PER_HOUR ((usec_t) (60ULL*USEC_PER_MINUTE))
#define NSEC_PER_HOUR ((nsec_t) (60ULL*NSEC_PER_MINUTE))
#define USEC_PER_DAY ((usec_t) (24ULL*USEC_PER_HOUR))
#define NSEC_PER_DAY ((nsec_t) (24ULL*NSEC_PER_HOUR))
#define USEC_PER_WEEK ((usec_t) (7ULL*USEC_PER_DAY))
#define NSEC_PER_WEEK ((nsec_t) (7ULL*NSEC_PER_DAY))
#define USEC_PER_MONTH ((usec_t) (2629800ULL*USEC_PER_SEC))
#define NSEC_PER_MONTH ((nsec_t) (2629800ULL*NSEC_PER_SEC))
#define USEC_PER_YEAR ((usec_t) (31557600ULL*USEC_PER_SEC))
#define NSEC_PER_YEAR ((nsec_t) (31557600ULL*NSEC_PER_SEC))
/* We assume a maximum timezone length of 6. TZNAME_MAX is not defined on Linux, but glibc internally initializes this
* to 6. Let's rely on that. */
#define FORMAT_TIMESTAMP_MAX (3U+1U+10U+1U+8U+1U+6U+1U+6U+1U)
#define FORMAT_TIMESTAMP_RELATIVE_MAX 256U
#define FORMAT_TIMESPAN_MAX 64U
#define TIME_T_MAX (time_t)((UINTMAX_C(1) << ((sizeof(time_t) << 3) - 1)) - 1)
#define DUAL_TIMESTAMP_NULL ((dual_timestamp) {})
#define DUAL_TIMESTAMP_INFINITY ((dual_timestamp) { USEC_INFINITY, USEC_INFINITY })
#define TRIPLE_TIMESTAMP_NULL ((triple_timestamp) {})
#define TIMESPEC_OMIT ((const struct timespec) { .tv_nsec = UTIME_OMIT })
usec_t now(clockid_t clock);
nsec_t now_nsec(clockid_t clock);
usec_t map_clock_usec_raw(usec_t from, usec_t from_base, usec_t to_base);
usec_t map_clock_usec(usec_t from, clockid_t from_clock, clockid_t to_clock);
dual_timestamp* dual_timestamp_now(dual_timestamp *ts);
dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u);
dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u);
dual_timestamp* dual_timestamp_from_boottime(dual_timestamp *ts, usec_t u);
triple_timestamp* triple_timestamp_now(triple_timestamp *ts);
triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u);
triple_timestamp* triple_timestamp_from_boottime(triple_timestamp *ts, usec_t u);
#define DUAL_TIMESTAMP_HAS_CLOCK(clock) \
IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC)
#define TRIPLE_TIMESTAMP_HAS_CLOCK(clock) \
IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM)
static inline bool timestamp_is_set(usec_t timestamp) {
return timestamp > 0 && timestamp != USEC_INFINITY;
}
static inline bool dual_timestamp_is_set(const dual_timestamp *ts) {
return timestamp_is_set(ts->realtime) ||
timestamp_is_set(ts->monotonic);
}
static inline bool triple_timestamp_is_set(const triple_timestamp *ts) {
return timestamp_is_set(ts->realtime) ||
timestamp_is_set(ts->monotonic) ||
timestamp_is_set(ts->boottime);
}
usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock);
usec_t timespec_load(const struct timespec *ts) _pure_;
nsec_t timespec_load_nsec(const struct timespec *ts) _pure_;
struct timespec* timespec_store(struct timespec *ts, usec_t u);
struct timespec* timespec_store_nsec(struct timespec *ts, nsec_t n);
#define TIMESPEC_STORE(u) timespec_store(&(struct timespec) {}, (u))
usec_t timeval_load(const struct timeval *tv) _pure_;
struct timeval* timeval_store(struct timeval *tv, usec_t u);
#define TIMEVAL_STORE(u) timeval_store(&(struct timeval) {}, (u))
char* format_timestamp_style(char *buf, size_t l, usec_t t, TimestampStyle style) _warn_unused_result_;
char* format_timestamp_relative_full(char *buf, size_t l, usec_t t, clockid_t clock, bool implicit_left) _warn_unused_result_;
char* format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy) _warn_unused_result_;
_warn_unused_result_
static inline char* format_timestamp_relative(char *buf, size_t l, usec_t t) {
return format_timestamp_relative_full(buf, l, t, CLOCK_REALTIME, /* implicit_left = */ false);
}
_warn_unused_result_
static inline char* format_timestamp_relative_monotonic(char *buf, size_t l, usec_t t) {
return format_timestamp_relative_full(buf, l, t, CLOCK_MONOTONIC, /* implicit_left = */ false);
}
_warn_unused_result_
static inline char* format_timestamp(char *buf, size_t l, usec_t t) {
return format_timestamp_style(buf, l, t, TIMESTAMP_PRETTY);
}
/* Note: the lifetime of the compound literal is the immediately surrounding block,
* see C11 §6.5.2.5, and
* https://stackoverflow.com/questions/34880638/compound-literal-lifetime-and-if-blocks */
#define FORMAT_TIMESTAMP(t) format_timestamp((char[FORMAT_TIMESTAMP_MAX]){}, FORMAT_TIMESTAMP_MAX, t)
#define FORMAT_TIMESTAMP_RELATIVE(t) \
format_timestamp_relative((char[FORMAT_TIMESTAMP_RELATIVE_MAX]){}, FORMAT_TIMESTAMP_RELATIVE_MAX, t)
#define FORMAT_TIMESTAMP_RELATIVE_MONOTONIC(t) \
format_timestamp_relative_monotonic((char[FORMAT_TIMESTAMP_RELATIVE_MAX]){}, FORMAT_TIMESTAMP_RELATIVE_MAX, t)
#define FORMAT_TIMESPAN(t, accuracy) format_timespan((char[FORMAT_TIMESPAN_MAX]){}, FORMAT_TIMESPAN_MAX, t, accuracy)
#define FORMAT_TIMESTAMP_STYLE(t, style) \
format_timestamp_style((char[FORMAT_TIMESTAMP_MAX]){}, FORMAT_TIMESTAMP_MAX, t, style)
int parse_timestamp(const char *t, usec_t *ret);
int parse_sec(const char *t, usec_t *ret);
int parse_sec_fix_0(const char *t, usec_t *ret);
int parse_sec_def_infinity(const char *t, usec_t *ret);
int parse_time(const char *t, usec_t *ret, usec_t default_unit);
int parse_nsec(const char *t, nsec_t *ret);
int get_timezones(char ***ret);
int verify_timezone(const char *name, int log_level);
static inline bool timezone_is_valid(const char *name, int log_level) {
return verify_timezone(name, log_level) >= 0;
}
bool clock_supported(clockid_t clock);
usec_t usec_shift_clock(usec_t, clockid_t from, clockid_t to);
int get_timezone(char **ret);
time_t mktime_or_timegm(struct tm *tm, bool utc);
struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);
uint32_t usec_to_jiffies(usec_t usec);
usec_t jiffies_to_usec(uint32_t jiffies);
bool in_utc_timezone(void);
static inline usec_t usec_add(usec_t a, usec_t b) {
/* Adds two time values, and makes sure USEC_INFINITY as input results as USEC_INFINITY in output,
* and doesn't overflow. */
if (a > USEC_INFINITY - b) /* overflow check */
return USEC_INFINITY;
return a + b;
}
static inline usec_t usec_sub_unsigned(usec_t timestamp, usec_t delta) {
if (timestamp == USEC_INFINITY) /* Make sure infinity doesn't degrade */
return USEC_INFINITY;
if (timestamp < delta)
return 0;
return timestamp - delta;
}
static inline usec_t usec_sub_signed(usec_t timestamp, int64_t delta) {
if (delta == INT64_MIN) { /* prevent overflow */
assert_cc(-(INT64_MIN + 1) == INT64_MAX);
assert_cc(USEC_INFINITY > INT64_MAX);
return usec_add(timestamp, (usec_t) INT64_MAX + 1);
}
if (delta < 0)
return usec_add(timestamp, (usec_t) (-delta));
return usec_sub_unsigned(timestamp, (usec_t) delta);
}
static inline int usleep_safe(usec_t usec) {
/* usleep() takes useconds_t that is (typically?) uint32_t. Also, usleep() may only support the
* range [0, 1000000]. See usleep(3). Let's override usleep() with clock_nanosleep().
*
* ⚠️ Note we are not using plain nanosleep() here, since that operates on CLOCK_REALTIME, not
* CLOCK_MONOTONIC! */
if (usec == 0)
return 0;
// FIXME: use RET_NERRNO() macro here. Currently, this header cannot include errno-util.h.
return clock_nanosleep(CLOCK_MONOTONIC, 0, TIMESPEC_STORE(usec), NULL) < 0 ? -errno : 0;
}
/* The last second we can format is 31. Dec 9999, 1s before midnight, because otherwise we'd enter 5 digit
* year territory. However, since we want to stay away from this in all timezones we take one day off. */
#define USEC_TIMESTAMP_FORMATTABLE_MAX_64BIT ((usec_t) 253402214399000000) /* Thu 9999-12-30 23:59:59 UTC */
/* With a 32-bit time_t we can't go beyond 2038...
* We parse timestamp with RFC-822/ISO 8601 (e.g. +06, or -03:00) as UTC, hence the upper bound must be off
* by USEC_PER_DAY. See parse_timestamp() for more details. */
#define USEC_TIMESTAMP_FORMATTABLE_MAX_32BIT (((usec_t) INT32_MAX) * USEC_PER_SEC - USEC_PER_DAY)
#if SIZEOF_TIME_T == 8
# define USEC_TIMESTAMP_FORMATTABLE_MAX USEC_TIMESTAMP_FORMATTABLE_MAX_64BIT
#elif SIZEOF_TIME_T == 4
# define USEC_TIMESTAMP_FORMATTABLE_MAX USEC_TIMESTAMP_FORMATTABLE_MAX_32BIT
#else
# error "Yuck, time_t is neither 4 nor 8 bytes wide?"
#endif
int time_change_fd(void);
const char* timestamp_style_to_string(TimestampStyle t) _const_;
TimestampStyle timestamp_style_from_string(const char *s) _pure_;