This commit is contained in:
bumbread 2023-02-16 07:44:12 +11:00
parent 7f97d4f729
commit b404ca0de3
2 changed files with 67 additions and 11 deletions

View File

@ -3,7 +3,7 @@
#define NS_PER_MS 1000000
#define TIME_TICKS_PER_SEC 1000000000ULL
#define NS_BEFORE_UNIX_EPOCH 11644473600000000000ULL
#define FT_TICKS_BEFORE_UNIX_EPOCH 116444736000000000ULL
typedef struct tm tm_t;
@ -35,8 +35,8 @@ static ULONGLONG _time_filetime_to_ns(FILETIME ft) {
static ULONGLONG _time_utc_ns() {
FILETIME ft;
GetSystemTimeAsFileTime(&ft);
ULONGLONG ns = _time_filetime_to_ns(ft);
ULONGLONG unix_ns = ns - NS_BEFORE_UNIX_EPOCH;
ULONGLONG ticks = _time_filetime_to_ns(ft);
ULONGLONG unix_ns = (ticks - FT_TICKS_BEFORE_UNIX_EPOCH*100);
return unix_ns;
}
@ -93,7 +93,7 @@ clock_t clock(void) {
}
time_t time(time_t *timer) {
ULONGLONG unix_nanos = _time_mono_ns();
ULONGLONG unix_nanos = _time_utc_ns();
time_t timer_ticks = unix_nanos;
if(timer != NULL) {
*timer = timer_ticks;
@ -362,24 +362,76 @@ tm_t *gmtime(const time_t *timer) {
return time;
}
tm_t *localtime(const time_t *timer) {
static bool _offset_utc_time_to_local(tm_t *time) {
TIME_ZONE_INFORMATION tz;
if(GetTimeZoneInformation(&tz) == TIME_ZONE_ID_INVALID) {
return NULL;
return false;
}
int bias = tz.Bias;
time->tm_min -= bias;
tm_t *local_time = gmtime(timer);
return local_time;
mktime(time);
return true;
}
tm_t *localtime(const time_t *timer) {
tm_t *utc_time = gmtime(timer);
if(!_offset_utc_time_to_local(utc_time)) {
return NULL;
}
return utc_time;
}
// String formatting
char *asctime(const tm_t *timeptr) {
static void _time_str_print2(char *str, int v) {
char hi = (v/10)%10 + '0';
char lo = v%10 + '0';
str[0] = hi;
str[1] = lo;
}
static void _time_str_print4(char *str, int v) {
char c1 = (v/1000)%10 + '0';
char c2 = (v/100)%10 + '0';
char c3 = (v/10)%10 + '0';
char c4 = v%10 + '0';
str[0] = c1;
str[1] = c2;
str[2] = c3;
str[3] = c4;
}
char *asctime(const struct tm *time) {
static const char wday_name[7][5] = {
"Sun ", "Mon ", "Tue ", "Wed ", "Thu ", "Fri ", "Sat ",
};
static const char mon_name[12][5] = {
"Jan ", "Feb ", "Mar ", "Apr ", "May ", "Jun ",
"Jul ", "Aug ", "Sep ", "Oct ", "Nov ", "Dec ",
};
char *buf = calloc(1, 26);
if(buf == NULL) {
return NULL;
}
strcpy(buf, wday_name[time->tm_wday]);
strcat(buf, mon_name[time->tm_mon]);
char *str = buf+8;
_time_str_print2(str+0, time->tm_mday);
_time_str_print2(str+3, time->tm_hour);
_time_str_print2(str+6, time->tm_min);
_time_str_print2(str+9, time->tm_sec);
str[2] = ' ';
str[5] = ':';
str[8] = ':';
str[11] = ' ';
_time_str_print4(str+12, 1900+time->tm_year);
str[16] = '\n';
str[17] = 0;
return buf;
}
char *ctime(const time_t *timer) {
return NULL;
return asctime(localtime(timer));
}
size_t strftime(char *restrict s, size_t size, const char *restrict fmt, const tm_t *restrict time) {

View File

@ -22,5 +22,9 @@ int main() {
char const *day_of_week = wday[time_str.tm_wday];
struct tm *gmt = gmtime(&timestamp);
struct tm *local = localtime(&timestamp);
puts(asctime(gmt));
puts(asctime(local));
time_t cur_time = time(NULL);
puts(ctime(&cur_time));
return 0;
}