Files
pepperOS/src/time/date.c
T

89 lines
1.9 KiB
C

/*
* @author xamidev <xamidev@riseup.net>
* @brief Date helper functions
* @license GPL-3.0-only
*/
#include <stdint.h>
#include <time/date.h>
#include <mem/utils.h>
#include <kernel.h>
extern struct boot_context boot_ctx;
// Unix epoch used as reference: Jan 1st 1970, 00:00:00 UTC
struct date epoch = {
.year = 1970,
.month = 1,
.day = 1,
.hour = 0,
.minute = 0,
.second = 0
};
/*
* date_timestamp_to_date - Convert UNIX timestamp to a date structure
* @timestamp: UNIX timestamp
*
* Return:
* <date> - date structure
*/
struct date date_timestamp_to_date(uint64_t timestamp)
{
struct date result;
memcpy(&result, &epoch, sizeof(struct date));
uint64_t nr_days = timestamp / 86400;
while (nr_days > 0) {
unsigned int nr_month = 0;
int leap_year = 0;
if (result.year % 4 == 0 && (result.year % 100 != 0 || result.year % 400 == 0)) {
leap_year = 1;
} else {
leap_year = 0;
}
if (result.month == 2) {
if (leap_year != 0) {
nr_month = 29;
} else {
nr_month = 28;
}
} else {
nr_month = 31 - ((result.month -1) % 7 % 2);
}
if (nr_days >= nr_month) {
nr_days -= nr_month;
result.month++;
if (result.month > 12) {
result.month = 1;
result.year++;
}
} else {
result.day += nr_days;
nr_days = 0;
}
}
result.second = timestamp % 60;
timestamp /= 60;
result.minute = timestamp % 60;
timestamp /= 60;
result.hour = timestamp % 24;
return result;
}
/*
* date_now - Get the current date (time at boot + timer ticks)
*
* Return:
* <date> - date structure
*/
struct date date_now()
{
uint64_t timestamp_now = boot_ctx.bootdate->boot_time + (ticks/1000);
return date_timestamp_to_date(timestamp_now);
}