175 lines
6.4 KiB
C++
175 lines
6.4 KiB
C++
|
//
|
|||
|
|
// Created by alex on 2022/5/29.
|
|||
|
|
//
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Copyright (c) 2018, Salvatore Sanfilippo <antirez at gmail dot com>
|
|||
|
|
* All rights reserved.
|
|||
|
|
*
|
|||
|
|
* Redistribution and use in source and binary forms, with or without
|
|||
|
|
* modification, are permitted provided that the following conditions are met:
|
|||
|
|
*
|
|||
|
|
* * Redistributions of source code must retain the above copyright notice,
|
|||
|
|
* this list of conditions and the following disclaimer.
|
|||
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|||
|
|
* notice, this list of conditions and the following disclaimer in the
|
|||
|
|
* documentation and/or other materials provided with the distribution.
|
|||
|
|
* * Neither the name of Redis nor the names of its contributors may be used
|
|||
|
|
* to endorse or promote products derived from this software without
|
|||
|
|
* specific prior written permission.
|
|||
|
|
*
|
|||
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|||
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|||
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|||
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|||
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|||
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|||
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|||
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|||
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|||
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|||
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#include <ctime>
|
|||
|
|
#ifndef _WIN32
|
|||
|
|
#include <sys/time.h>
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
/* This is a safe version of localtime() which contains no locks and is
|
|||
|
|
* fork() friendly. Even the _r version of localtime() cannot be used safely
|
|||
|
|
* in Redis. Another thread may be calling localtime() while the main thread
|
|||
|
|
* forks(). Later when the child process calls localtime() again, for instance
|
|||
|
|
* in order to log something to the Redis log, it may deadlock: in the copy
|
|||
|
|
* of the address space of the forked process the lock will never be released.
|
|||
|
|
*
|
|||
|
|
* This function takes the timezone 'tz' as argument, and the 'dst' flag is
|
|||
|
|
* used to check if daylight saving time is currently in effect. The caller
|
|||
|
|
* of this function should obtain such information calling tzset() ASAP in the
|
|||
|
|
* main() function to obtain the timezone offset from the 'timezone' global
|
|||
|
|
* variable. To obtain the daylight information, if it is currently active or not,
|
|||
|
|
* one trick is to call localtime() in main() ASAP as well, and get the
|
|||
|
|
* information from the tm_isdst field of the tm structure. However the daylight
|
|||
|
|
* time may switch in the future for long running processes, so this information
|
|||
|
|
* should be refreshed at safe times.
|
|||
|
|
*
|
|||
|
|
* Note that this function does not work for dates < 1/1/1970, it is solely
|
|||
|
|
* designed to work with what time(NULL) may return, and to support Redis
|
|||
|
|
* logging of the dates, it's not really a complete implementation. */
|
|||
|
|
namespace toolkit {
|
|||
|
|
static int _daylight_active;
|
|||
|
|
static long _current_timezone;
|
|||
|
|
|
|||
|
|
int get_daylight_active() {
|
|||
|
|
return _daylight_active;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
static int is_leap_year(time_t year) {
|
|||
|
|
if (year % 4)
|
|||
|
|
return 0; /* A year not divisible by 4 is not leap. */
|
|||
|
|
else if (year % 100)
|
|||
|
|
return 1; /* If div by 4 and not 100 is surely leap. */
|
|||
|
|
else if (year % 400)
|
|||
|
|
return 0; /* If div by 100 *and* not by 400 is not leap. */
|
|||
|
|
else
|
|||
|
|
return 1; /* If div by 100 and 400 is leap. */
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
void no_locks_localtime(struct tm *tmp, time_t t) {
|
|||
|
|
const time_t secs_min = 60;
|
|||
|
|
const time_t secs_hour = 3600;
|
|||
|
|
const time_t secs_day = 3600 * 24;
|
|||
|
|
|
|||
|
|
t -= _current_timezone; /* Adjust for timezone. */
|
|||
|
|
t += 3600 * get_daylight_active(); /* Adjust for daylight time. */
|
|||
|
|
time_t days = t / secs_day; /* Days passed since epoch. */
|
|||
|
|
time_t seconds = t % secs_day; /* Remaining seconds. */
|
|||
|
|
|
|||
|
|
tmp->tm_isdst = get_daylight_active();
|
|||
|
|
tmp->tm_hour = seconds / secs_hour;
|
|||
|
|
tmp->tm_min = (seconds % secs_hour) / secs_min;
|
|||
|
|
tmp->tm_sec = (seconds % secs_hour) % secs_min;
|
|||
|
|
#ifndef _WIN32
|
|||
|
|
tmp->tm_gmtoff = -_current_timezone;
|
|||
|
|
#endif
|
|||
|
|
/* 1/1/1970 was a Thursday, that is, day 4 from the POV of the tm structure
|
|||
|
|
* where sunday = 0, so to calculate the day of the week we have to add 4
|
|||
|
|
* and take the modulo by 7. */
|
|||
|
|
tmp->tm_wday = (days + 4) % 7;
|
|||
|
|
|
|||
|
|
/* Calculate the current year. */
|
|||
|
|
tmp->tm_year = 1970;
|
|||
|
|
while (1) {
|
|||
|
|
/* Leap years have one day more. */
|
|||
|
|
time_t days_this_year = 365 + is_leap_year(tmp->tm_year);
|
|||
|
|
if (days_this_year > days)
|
|||
|
|
break;
|
|||
|
|
days -= days_this_year;
|
|||
|
|
tmp->tm_year++;
|
|||
|
|
}
|
|||
|
|
tmp->tm_yday = days; /* Number of day of the current year. */
|
|||
|
|
|
|||
|
|
/* We need to calculate in which month and day of the month we are. To do
|
|||
|
|
* so we need to skip days according to how many days there are in each
|
|||
|
|
* month, and adjust for the leap year that has one more day in February. */
|
|||
|
|
int mdays[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
|
|||
|
|
mdays[1] += is_leap_year(tmp->tm_year);
|
|||
|
|
|
|||
|
|
tmp->tm_mon = 0;
|
|||
|
|
while (days >= mdays[tmp->tm_mon]) {
|
|||
|
|
days -= mdays[tmp->tm_mon];
|
|||
|
|
tmp->tm_mon++;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
tmp->tm_mday = days + 1; /* Add 1 since our 'days' is zero-based. */
|
|||
|
|
tmp->tm_year -= 1900; /* Surprisingly tm_year is year-1900. */
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
void local_time_init() {
|
|||
|
|
/* Obtain timezone and daylight info. */
|
|||
|
|
tzset(); /* Now 'timezome' global is populated. */
|
|||
|
|
#if defined(__linux__) || defined(__sun)
|
|||
|
|
_current_timezone = timezone;
|
|||
|
|
#elif defined(_WIN32)
|
|||
|
|
time_t time_utc;
|
|||
|
|
struct tm tm_local;
|
|||
|
|
|
|||
|
|
// Get the UTC time
|
|||
|
|
time(&time_utc);
|
|||
|
|
|
|||
|
|
// Get the local time
|
|||
|
|
// Use localtime_r for threads safe for linux
|
|||
|
|
//localtime_r(&time_utc, &tm_local);
|
|||
|
|
localtime_s(&tm_local, &time_utc);
|
|||
|
|
|
|||
|
|
time_t time_local;
|
|||
|
|
struct tm tm_gmt;
|
|||
|
|
|
|||
|
|
// Change tm to time_t
|
|||
|
|
time_local = mktime(&tm_local);
|
|||
|
|
|
|||
|
|
// Change it to GMT tm
|
|||
|
|
//gmtime_r(&time_utc, &tm_gmt);//linux
|
|||
|
|
gmtime_s(&tm_gmt, &time_utc);
|
|||
|
|
|
|||
|
|
int time_zone = tm_local.tm_hour - tm_gmt.tm_hour;
|
|||
|
|
if (time_zone < -12) {
|
|||
|
|
time_zone += 24;
|
|||
|
|
}
|
|||
|
|
else if (time_zone > 12) {
|
|||
|
|
time_zone -= 24;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
_current_timezone = time_zone;
|
|||
|
|
#else
|
|||
|
|
struct timeval tv;
|
|||
|
|
struct timezone tz;
|
|||
|
|
gettimeofday(&tv, &tz);
|
|||
|
|
_current_timezone = tz.tz_minuteswest * 60L;
|
|||
|
|
#endif
|
|||
|
|
time_t t = time(NULL);
|
|||
|
|
struct tm *aux = localtime(&t);
|
|||
|
|
_daylight_active = aux->tm_isdst;
|
|||
|
|
}
|
|||
|
|
} // namespace toolkit
|