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Diffstat (limited to 'time/gmtime_r.c')
| -rw-r--r-- | time/gmtime_r.c | 144 |
1 files changed, 0 insertions, 144 deletions
diff --git a/time/gmtime_r.c b/time/gmtime_r.c deleted file mode 100644 index 22658ea..0000000 --- a/time/gmtime_r.c +++ /dev/null @@ -1,144 +0,0 @@ -/* - * (C)2012 Michael Duane Rice 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 the copyright holders - * nor the names of 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. - */ - -/* $Id: gmtime_r.c 2369 2013-04-28 14:19:35Z swfltek $ */ - -/* Re entrant version of gmtime(). */ - -#include <time.h> -#include <stdlib.h> -#include <inttypes.h> - -void -gmtime_r(const time_t * timer, struct tm * timeptr) -{ - int32_t fract; - ldiv_t lresult; - div_t result; - uint16_t days, n, leapyear, years; - - /* break down timer into whole and fractional parts of 1 day */ - days = *timer / 86400UL; - fract = *timer % 86400UL; - - /* - Extract hour, minute, and second from the fractional day - */ - lresult = ldiv(fract, 60L); - timeptr->tm_sec = lresult.rem; - result = div(lresult.quot, 60); - timeptr->tm_min = result.rem; - timeptr->tm_hour = result.quot; - - /* Determine day of week ( the epoch was a Saturday ) */ - n = days + SATURDAY; - n %= 7; - timeptr->tm_wday = n; - - /* - * Our epoch year has the property of being at the conjunction of all three 'leap cycles', - * 4, 100, and 400 years ( though we can ignore the 400 year cycle in this library). - * - * Using this property, we can easily 'map' the time stamp into the leap cycles, quickly - * deriving the year and day of year, along with the fact of whether it is a leap year. - */ - - /* map into a 100 year cycle */ - lresult = ldiv((long) days, 36525L); - years = 100 * lresult.quot; - - /* map into a 4 year cycle */ - lresult = ldiv(lresult.rem, 1461L); - years += 4 * lresult.quot; - days = lresult.rem; - if (years > 100) - days++; - - /* - * 'years' is now at the first year of a 4 year leap cycle, which will always be a leap year, - * unless it is 100. 'days' is now an index into that cycle. - */ - leapyear = 1; - if (years == 100) - leapyear = 0; - - /* compute length, in days, of first year of this cycle */ - n = 364 + leapyear; - - /* - * if the number of days remaining is greater than the length of the - * first year, we make one more division. - */ - if (days > n) { - days -= leapyear; - leapyear = 0; - result = div(days, 365); - years += result.quot; - days = result.rem; - } - timeptr->tm_year = 100 + years; - timeptr->tm_yday = days; - - /* - Given the year, day of year, and leap year indicator, we can break down the - month and day of month. If the day of year is less than 59 (or 60 if a leap year), then - we handle the Jan/Feb month pair as an exception. - */ - n = 59 + leapyear; - if (days < n) { - /* special case: Jan/Feb month pair */ - result = div(days, 31); - timeptr->tm_mon = result.quot; - timeptr->tm_mday = result.rem; - } else { - /* - The remaining 10 months form a regular pattern of 31 day months alternating with 30 day - months, with a 'phase change' between July and August (153 days after March 1). - We proceed by mapping our position into either March-July or August-December. - */ - days -= n; - result = div(days, 153); - timeptr->tm_mon = 2 + result.quot * 5; - - /* map into a 61 day pair of months */ - result = div(result.rem, 61); - timeptr->tm_mon += result.quot * 2; - - /* map into a month */ - result = div(result.rem, 31); - timeptr->tm_mon += result.quot; - timeptr->tm_mday = result.rem; - } - - /* - Cleanup and return - */ - timeptr->tm_isdst = 0; /* gmt is never in DST */ - timeptr->tm_mday++; /* tm_mday is 1 based */ - -} |