tmxmake.c revision 34f9b3eef6fdadbda0a846aa4d68691ac40eace5
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2009 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* Time_t conversion support
*/
#include <tmx.h>
#include "FEATURE/tmlib"
/*
* return Tm_t for t
* time zone and leap seconds accounted for in return value
*/
Tm_t*
tmxtm(register Tm_t* tm, Time_t t, Tm_zone_t* zone)
{
register struct tm* tp;
register Tm_leap_t* lp;
Time_t x;
time_t now;
int leapsec;
int y;
uint32_t n;
int32_t o;
#if TMX_FLOAT
Time_t z;
uint32_t i;
#endif
tmset(tm_info.zone);
leapsec = 0;
if ((tm_info.flags & (TM_ADJUST|TM_LEAP)) == (TM_ADJUST|TM_LEAP) && (n = tmxsec(t)))
{
for (lp = &tm_data.leap[0]; n < lp->time; lp++);
if (lp->total)
{
if (n == lp->time && (leapsec = (lp->total - (lp+1)->total)) < 0)
leapsec = 0;
t = tmxsns(n - lp->total, tmxnsec(t));
}
}
x = tmxsec(t);
if (!(tm->tm_zone = zone))
{
if (tm_info.flags & TM_UTC)
tm->tm_zone = &tm_data.zone[2];
else
tm->tm_zone = tm_info.zone;
}
if ((o = 60 * tm->tm_zone->west) && x > o)
{
x -= o;
o = 0;
}
#if TMX_FLOAT
i = x / (24 * 60 * 60);
z = i;
n = x - z * (24 * 60 * 60);
tm->tm_sec = n % 60 + leapsec;
n /= 60;
tm->tm_min = n % 60;
n /= 60;
tm->tm_hour = n % 24;
#define x i
#else
tm->tm_sec = x % 60 + leapsec;
x /= 60;
tm->tm_min = x % 60;
x /= 60;
tm->tm_hour = x % 24;
x /= 24;
#endif
tm->tm_wday = (x + 4) % 7;
tm->tm_year = (400 * (x + 25202)) / 146097 + 1;
n = tm->tm_year - 1;
x -= n * 365 + n / 4 - n / 100 + (n + (1900 - 1600)) / 400 - (1970 - 1901) * 365 - (1970 - 1901) / 4;
tm->tm_mon = 0;
tm->tm_mday = x + 1;
tm->tm_nsec = tmxnsec(t);
tmfix(tm);
n += 1900;
tm->tm_isdst = 0;
if (tm->tm_zone->daylight)
{
if ((y = tmequiv(tm) - 1900) == tm->tm_year)
now = tmxsec(t);
else
{
Tm_t te;
te = *tm;
te.tm_year = y;
now = tmxsec(tmxtime(&te, tm->tm_zone->west));
}
if ((tp = tmlocaltime(&now)) && ((tm->tm_isdst = tp->tm_isdst) || o))
{
tm->tm_min -= o / 60 + (tm->tm_isdst ? tm->tm_zone->dst : 0);
tmfix(tm);
}
}
return tm;
}
/*
* return Tm_t for t
* time zone and leap seconds accounted for in return value
*/
Tm_t*
tmxmake(Time_t t)
{
static Tm_t ts;
return tmxtm(&ts, t, NiL);
}