root/date/lib/unixtime2tm.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. timelib_unixtime2gmt
  2. timelib_update_from_sse
  3. timelib_unixtime2local
  4. timelib_set_timezone
  5. timelib_apply_localtime

/*
   +----------------------------------------------------------------------+
   | PHP Version 5                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2013 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Derick Rethans <derick@derickrethans.nl>                    |
   +----------------------------------------------------------------------+
 */

/* $Id$ */

#include "timelib.h"

#include <stdio.h>

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif

static int month_tab_leap[12] = { -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
static int month_tab[12] =      { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };


/* Converts a Unix timestamp value into broken down time, in GMT */
void timelib_unixtime2gmt(timelib_time* tm, timelib_sll ts)
{
        timelib_sll days, remainder, tmp_days;
        timelib_sll cur_year = 1970;
        timelib_sll i;
        timelib_sll hours, minutes, seconds;
        int *months;

        days = ts / SECS_PER_DAY;
        remainder = ts - (days * SECS_PER_DAY);
        if (ts < 0 && remainder == 0) {
                days++;
                remainder -= SECS_PER_DAY;
        }
        TIMELIB_DEBUG(printf("days=%lld, rem=%lld\n", days, remainder););

        if (ts >= 0) {
                tmp_days = days + 1;

                if (tmp_days >= DAYS_PER_LYEAR_PERIOD || tmp_days <= -DAYS_PER_LYEAR_PERIOD) {
                        cur_year += YEARS_PER_LYEAR_PERIOD * (tmp_days / DAYS_PER_LYEAR_PERIOD);
                        tmp_days -= DAYS_PER_LYEAR_PERIOD * (tmp_days / DAYS_PER_LYEAR_PERIOD);
                }

                while (tmp_days >= DAYS_PER_LYEAR) {
                        cur_year++;
                        if (timelib_is_leap(cur_year)) {
                                tmp_days -= DAYS_PER_LYEAR;
                        } else {
                                tmp_days -= DAYS_PER_YEAR;
                        }
                }
        } else {
                tmp_days = days;

                /* Guess why this might be for, it has to do with a pope ;-). It's also
                 * only valid for Great Brittain and it's colonies. It needs fixing for
                 * other locales. *sigh*, why is this crap so complex! */
                /*
                if (ts <= TIMELIB_LL_CONST(-6857352000)) {
                        tmp_days -= 11;
                }
                */

                while (tmp_days <= 0) {
                        if (tmp_days < -1460970) {
                                cur_year -= 4000;
                                TIMELIB_DEBUG(printf("tmp_days=%lld, year=%lld\n", tmp_days, cur_year););
                                tmp_days += 1460970;
                        } else {
                                cur_year--;
                                TIMELIB_DEBUG(printf("tmp_days=%lld, year=%lld\n", tmp_days, cur_year););
                                if (timelib_is_leap(cur_year)) {
                                        tmp_days += DAYS_PER_LYEAR;
                                } else {
                                        tmp_days += DAYS_PER_YEAR;
                                }
                        }
                }
                remainder += SECS_PER_DAY;
        }
        TIMELIB_DEBUG(printf("tmp_days=%lld, year=%lld\n", tmp_days, cur_year););

        months = timelib_is_leap(cur_year) ? month_tab_leap : month_tab;
        if (timelib_is_leap(cur_year) && cur_year < 1970) {
                tmp_days--;
        }
        i = 11;
        while (i > 0) {
                TIMELIB_DEBUG(printf("month=%lld (%d)\n", i, months[i]););
                if (tmp_days > months[i]) {
                        break;
                }
                i--;
        }
        TIMELIB_DEBUG(printf("A: ts=%lld, year=%lld, month=%lld, day=%lld,", ts, cur_year, i + 1, tmp_days - months[i]););

        /* That was the date, now we do the tiiiime */
        hours = remainder / 3600;
        minutes = (remainder - hours * 3600) / 60;
        seconds = remainder % 60;
        TIMELIB_DEBUG(printf(" hour=%lld, minute=%lld, second=%lld\n", hours, minutes, seconds););

        tm->y = cur_year;
        tm->m = i + 1;
        tm->d = tmp_days - months[i];
        tm->h = hours;
        tm->i = minutes;
        tm->s = seconds;
        tm->z = 0;
        tm->dst = 0;
        tm->sse = ts;
        tm->sse_uptodate = 1;
        tm->tim_uptodate = 1;
        tm->is_localtime = 0;
}

void timelib_update_from_sse(timelib_time *tm)
{
        timelib_sll sse;

        sse = tm->sse;
        
        switch (tm->zone_type) {
                case TIMELIB_ZONETYPE_ABBR:
                case TIMELIB_ZONETYPE_OFFSET: {
                        int z = tm->z;
                        signed int dst = tm->dst;
                        
                        timelib_unixtime2gmt(tm, tm->sse - (tm->z * 60) + (tm->dst * 3600));

                        tm->z = z;
                        tm->dst = dst;
                        goto cleanup;
                }

                case TIMELIB_ZONETYPE_ID: {
                        timelib_time_offset *gmt_offset;
                        
                        gmt_offset = timelib_get_time_zone_info(tm->sse, tm->tz_info);
                        timelib_unixtime2gmt(tm, tm->sse + gmt_offset->offset);
                        timelib_time_offset_dtor(gmt_offset);
                        
                        goto cleanup;
                }

                default:
                        timelib_unixtime2gmt(tm, tm->sse);
                        goto cleanup;
        }
cleanup:
        tm->sse = sse;
        tm->is_localtime = 1;
        tm->have_zone = 1;
}

void timelib_unixtime2local(timelib_time *tm, timelib_sll ts)
{
        timelib_time_offset *gmt_offset;
        timelib_tzinfo      *tz = tm->tz_info;

        switch (tm->zone_type) {
                case TIMELIB_ZONETYPE_ABBR:
                case TIMELIB_ZONETYPE_OFFSET: {
                        int z = tm->z;
                        signed int dst = tm->dst;
                        
                        timelib_unixtime2gmt(tm, ts - (tm->z * 60) + (tm->dst * 3600));

                        tm->z = z;
                        tm->dst = dst;
                        break;
                }

                case TIMELIB_ZONETYPE_ID:
                        gmt_offset = timelib_get_time_zone_info(ts, tz);
                        timelib_unixtime2gmt(tm, ts + gmt_offset->offset);

                        /* we need to reset the sse here as unixtime2gmt modifies it */
                        tm->sse = ts; 
                        tm->dst = gmt_offset->is_dst;
                        tm->z = gmt_offset->offset;
                        tm->tz_info = tz;

                        timelib_time_tz_abbr_update(tm, gmt_offset->abbr);
                        timelib_time_offset_dtor(gmt_offset);
                        break;

                default:
                        tm->is_localtime = 0;
                        tm->have_zone = 0;
                        return;
        }

        tm->is_localtime = 1;
        tm->have_zone = 1;
}

void timelib_set_timezone(timelib_time *t, timelib_tzinfo *tz)
{
        timelib_time_offset *gmt_offset;

        gmt_offset = timelib_get_time_zone_info(t->sse, tz);
        t->z = gmt_offset->offset;
/*
        if (t->dst != gmt_offset->is_dst) {
                printf("ERROR (%d, %d)\n", t->dst, gmt_offset->is_dst);
                exit(1);
        }
*/
        t->dst = gmt_offset->is_dst;
        t->tz_info = tz;
        if (t->tz_abbr) {
                free(t->tz_abbr);
        }
        t->tz_abbr = strdup(gmt_offset->abbr);
        timelib_time_offset_dtor(gmt_offset);

        t->have_zone = 1;
        t->zone_type = TIMELIB_ZONETYPE_ID;
}

/* Converts the time stored in the struct to localtime if localtime = true,
 * otherwise it converts it to gmttime. This is only done when necessary
 * ofcourse. */
int timelib_apply_localtime(timelib_time *t, unsigned int localtime)
{
        if (localtime) {
                /* Converting from GMT time to local time */
                TIMELIB_DEBUG(printf("Converting from GMT time to local time\n"););

                /* Check if TZ is set */
                if (!t->tz_info) {
                        TIMELIB_DEBUG(printf("E: No timezone configured, can't switch to local time\n"););
                        return -1;
                }

                timelib_unixtime2local(t, t->sse);
        } else {
                /* Converting from local time to GMT time */
                TIMELIB_DEBUG(printf("Converting from local time to GMT time\n"););

                timelib_unixtime2gmt(t, t->sse);
        }
        return 0;
}

/* [<][>][^][v][top][bottom][index][help] */