lotuswordpro/source/filter/localtime.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  10  *  Sun Microsystems Inc., October, 2000
  11  *
  12  *  GNU Lesser General Public License Version 2.1
  13  *  =============================================
  14  *  Copyright 2000 by Sun Microsystems, Inc.
  15  *  901 San Antonio Road, Palo Alto, CA 94303, USA
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  17  *  This library is free software; you can redistribute it and/or
  18  *  modify it under the terms of the GNU Lesser General Public
  19  *  License version 2.1, as published by the Free Software Foundation.
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  31  *
  32  *  Sun Industry Standards Source License Version 1.1
  33  *  =================================================
  34  *  The contents of this file are subject to the Sun Industry Standards
  35  *  Source License Version 1.1 (the "License"); You may not use this file
  36  *  except in compliance with the License. You may obtain a copy of the
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  46  *  The Initial Developer of the Original Code is: IBM Corporation
  47  *
  48  *  Copyright: 2008 by IBM Corporation
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  52  *  Contributor(s): _______________________________________
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  55  ************************************************************************/
  56 #include "localtime.hxx"
  57 #include <limits.h>
  58 #include <unicode/timezone.h>
  59 //End by
  60 const long DAY_SEC =24 * 60 * 60;
  61 const long YEAR_SEC = 365 * DAY_SEC;
  62 const long FOURYEAR_SEC = 4 * YEAR_SEC + DAY_SEC;
  63 #ifndef LONG_MAX
  64 const long LONG_MAX=2147483647;
  65 #endif
  66 const long TIMEZONE = -28800;
  67 //01-01-70 was a Thursday
  68 const long BASE_DOW = 4;
  69
  70 long _lpdays[] = {-1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365};
  71
  72 long _days[] = {-1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364};
  73
  74 bool LtgGmTime(long rtime,LtTm& rtm)
  75 {
  76     if (rtime < 0)
  77     {
  78         return false;
  79     }
  80     //is-current-year-a-leap-year flag
  81     int islpyr = 0;
  82
  83     long tmptim;
  84     long caltim = rtime;
  85     tmptim = (long)(caltim / FOURYEAR_SEC);
  86     caltim -= ((long)tmptim * FOURYEAR_SEC);
  87
  88     //
  89     //Determine which year of the interval
  90     //
  91     // 1970, 1974, 1978,...,etc.
  92     tmptim = (tmptim * 4) + 70;
  93
  94     if (caltim >= YEAR_SEC)
  95     {
  96         //1971, 1975, 1979,...,etc.
  97         tmptim++;
  98         caltim -= YEAR_SEC;
  99
 100         if ( caltim >= YEAR_SEC )
 101         {
 102             // 1972, 1976, 1980,...,etc.
 103             tmptim++;
 104             caltim -= YEAR_SEC;
 105
 106             //Note, it takes 366 days-worth of seconds to get past a leap year.
 107             if (caltim >= (YEAR_SEC + DAY_SEC))
 108             {
 109                 //1973, 1977, 1981,...,etc.
 110                 tmptim++;
 111                 caltim -= (YEAR_SEC + DAY_SEC);
 112             }
 113             else
 114             {
 115                 //In a leap year after all, set the flag.
 116                 islpyr++;
 117             }
 118         }
 119     }
 120
 121     //
 122     //tmptim now holds the value for tm_year. caltim now holds the
 123     //number of elapsed seconds since the beginning of that year.
 124     //
 125     rtm.tm_year = tmptim;
 126     //
 127     //Determine days since January 1 (0 - 365). This is the tm_yday value.
 128     //Leave caltim with number of elapsed seconds in that day.
 129     //
 130     rtm.tm_yday = (long)(caltim / DAY_SEC);
 131     caltim -= (long)(rtm.tm_yday) * DAY_SEC;
 132     //
 133     //Determine months since January (0 - 11) and day of month (1 - 31)
 134     //
 135     long* mdays;
 136     if ( islpyr )
 137     {
 138         mdays = _lpdays;
 139     }
 140     else
 141     {
 142         mdays = _days;
 143     }
 144
 145     for ( tmptim = 1 ; mdays[tmptim] < rtm.tm_yday ; tmptim++ ) ;
 146
 147     rtm.tm_mon = --tmptim;
 148
 149     rtm.tm_mday = rtm.tm_yday - mdays[tmptim];
 150
 151     //
 152     //Determine days since Sunday (0 - 6)
 153     //
 154     rtm.tm_wday = ((long)(rtime / DAY_SEC) + BASE_DOW) % 7;
 155     //
 156     //Determine hours since midnight (0 - 23), minutes after the hour
 157     //(0 - 59), and seconds after the minute (0 - 59).
 158     //
 159     rtm.tm_hour = (long)(caltim / 3600);
 160     caltim -= (long)rtm.tm_hour * 3600;
 161
 162     rtm.tm_min = (long)(caltim / 60);
 163     rtm.tm_sec = (long)(caltim - (rtm.tm_min) * 60);
 164
 165     rtm.tm_isdst = 0;
 166
 167     //
 168     //
 169     //
 170     //adjust year & month
 171     rtm.tm_year += 1900;
 172     ++(rtm.tm_mon);
 173
 174     return true;
 175
 176 };
 177 bool LtgLocalTime(long rtime,LtTm& rtm)
 178 {
 179     if (rtime < 0)
 180     {
 181         return false;
 182     }
 183
 184     if ((rtime > 3 * DAY_SEC)&&(rtime < LONG_MAX - 3 * DAY_SEC))
 185     {
 186         TimeZone* pLocalZone = TimeZone::createDefault();
 187         long offset = (pLocalZone->getRawOffset())/1000;
 188         delete pLocalZone;
 189         long ltime = rtime + offset;
 190         return LtgGmTime(ltime,rtm);
 191     }
 192     return false;
 193 };
 194
 195 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */