/*
* Taken from FreeBSD src / lib / libc / stdtime / localtime.c 1.43 revision.
* localtime.c 7.78.
* tzfile.h 1.8
* adapted to be replacement gmtime_r.
*/
#include "config.h"
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#define MONSPERYEAR 12
#define DAYSPERNYEAR 365
#define DAYSPERLYEAR 366
#define SECSPERMIN 60
#define SECSPERHOUR (60*60)
#define SECSPERDAY (24*60*60)
#define DAYSPERWEEK 7
#define TM_SUNDAY 0
#define TM_MONDAY 1
#define TM_TUESDAY 2
#define TM_WEDNESDAY 3
#define TM_THURSDAY 4
#define TM_FRIDAY 5
#define TM_SATURDAY 6
#define TM_YEAR_BASE 1900
#define EPOCH_YEAR 1970
#define EPOCH_WDAY TM_THURSDAY
#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
static const int mon_lengths[2][MONSPERYEAR] = {
{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
};
static const int year_lengths[2] = {
DAYSPERNYEAR, DAYSPERLYEAR
};
static void
timesub(timep, offset, tmp)
const time_t * const timep;
const long offset;
struct tm * const tmp;
{
long days;
long rem;
long y;
int yleap;
const int * ip;
days = *timep / SECSPERDAY;
rem = *timep % SECSPERDAY;
rem += (offset);
while (rem < 0) {
rem += SECSPERDAY;
--days;
}
while (rem >= SECSPERDAY) {
rem -= SECSPERDAY;
++days;
}
tmp->tm_hour = (int) (rem / SECSPERHOUR);
rem = rem % SECSPERHOUR;
tmp->tm_min = (int) (rem / SECSPERMIN);
/*
** A positive leap second requires a special
** representation. This uses "... ??:59:60" et seq.
*/
tmp->tm_sec = (int) (rem % SECSPERMIN) ;
tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
if (tmp->tm_wday < 0)
tmp->tm_wday += DAYSPERWEEK;
y = EPOCH_YEAR;
#define LEAPS_THRU_END_OF(y) ((y) / 4 - (y) / 100 + (y) / 400)
while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
long newy;
newy = y + days / DAYSPERNYEAR;
if (days < 0)
--newy;
days -= (newy - y) * DAYSPERNYEAR +
LEAPS_THRU_END_OF(newy - 1) -
LEAPS_THRU_END_OF(y - 1);
y = newy;
}
tmp->tm_year = y - TM_YEAR_BASE;
tmp->tm_yday = (int) days;
ip = mon_lengths[yleap];
for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
days = days - (long) ip[tmp->tm_mon];
tmp->tm_mday = (int) (days + 1);
tmp->tm_isdst = 0;
}
/*
* Re-entrant version of gmtime.
*/
struct tm * gmtime_r(const time_t* timep, struct tm *tm)
{
timesub(timep, 0L, tm);
return tm;
}
