lotuswordpro/source/filter/localtime.cxx

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   4  *  The Contents of this file are made available subject to the terms of
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   7  *         - GNU Lesser General Public License Version 2.1
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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
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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 #include <memory>
  60
  61 const tools::Long DAY_SEC = 24 * 60 * 60;
  62 const tools::Long YEAR_SEC = 365 * DAY_SEC;
  63 const tools::Long FOURYEAR_SEC = 4 * YEAR_SEC + DAY_SEC;
  64 #ifndef LONG_MAX
  65 const long LONG_MAX = 2147483647;
  66 #endif
  67 //01-01-70 was a Thursday
  68 const tools::Long BASE_DOW = 4;
  69
  70 bool LtgGmTime(tools::Long rtime, LtTm& rtm)
  71 {
  72     if (rtime < 0)
  73     {
  74         return false;
  75     }
  76     //is-current-year-a-leap-year flag
  77     int islpyr = 0;
  78
  79     tools::Long tmptim;
  80     tools::Long caltim = rtime;
  81     tmptim = static_cast<tools::Long>(caltim / FOURYEAR_SEC);
  82     caltim -= tmptim * FOURYEAR_SEC;
  83
  84     //Determine which year of the interval
  85
  86     // 1970, 1974, 1978,...,etc.
  87     tmptim = (tmptim * 4) + 70;
  88
  89     if (caltim >= YEAR_SEC)
  90     {
  91         //1971, 1975, 1979,...,etc.
  92         tmptim++;
  93         caltim -= YEAR_SEC;
  94
  95         if (caltim >= YEAR_SEC)
  96         {
  97             // 1972, 1976, 1980,...,etc.
  98             tmptim++;
  99             caltim -= YEAR_SEC;
 100
 101             //Note, it takes 366 days-worth of seconds to get past a leap year.
 102             if (caltim >= (YEAR_SEC + DAY_SEC))
 103             {
 104                 //1973, 1977, 1981,...,etc.
 105                 tmptim++;
 106                 caltim -= (YEAR_SEC + DAY_SEC);
 107             }
 108             else
 109             {
 110                 //In a leap year after all, set the flag.
 111                 islpyr++;
 112             }
 113         }
 114     }
 115
 116     //tmptim now holds the value for tm_year. caltim now holds the
 117     //number of elapsed seconds since the beginning of that year.
 118
 119     rtm.tm_year = tmptim;
 120
 121     //Determine days since January 1 (0 - 365). This is the tm_yday value.
 122     //Leave caltim with number of elapsed seconds in that day.
 123
 124     rtm.tm_yday = static_cast<tools::Long>(caltim / DAY_SEC);
 125     caltim -= rtm.tm_yday * DAY_SEC;
 126
 127     //Determine months since January (0 - 11) and day of month (1 - 31)
 128
 129     tools::Long const* mdays;
 130     if (islpyr)
 131     {
 132         static tools::Long const lpdays[]
 133             = { -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 };
 134         mdays = lpdays;
 135     }
 136     else
 137     {
 138         static tools::Long const days[]
 139             = { -1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364 };
 140         mdays = days;
 141     }
 142
 143     for (tmptim = 1; mdays[tmptim] < rtm.tm_yday; tmptim++)
 144         ;
 145
 146     rtm.tm_mon = --tmptim;
 147
 148     rtm.tm_mday = rtm.tm_yday - mdays[tmptim];
 149
 150     //Determine days since Sunday (0 - 6)
 151
 152     rtm.tm_wday = (static_cast<tools::Long>(rtime / DAY_SEC) + BASE_DOW) % 7;
 153
 154     //Determine hours since midnight (0 - 23), minutes after the hour
 155     //(0 - 59), and seconds after the minute (0 - 59).
 156
 157     rtm.tm_hour = static_cast<tools::Long>(caltim / 3600);
 158     caltim -= rtm.tm_hour * 3600;
 159
 160     rtm.tm_min = static_cast<tools::Long>(caltim / 60);
 161     rtm.tm_sec = static_cast<tools::Long>(caltim - (rtm.tm_min) * 60);
 162
 163     //adjust year & month
 164     rtm.tm_year += 1900;
 165     ++(rtm.tm_mon);
 166
 167     return true;
 168 };
 169 bool LtgLocalTime(tools::Long rtime, LtTm& rtm)
 170 {
 171     if (rtime < 0)
 172     {
 173         return false;
 174     }
 175
 176     if ((rtime > 3 * DAY_SEC) && (rtime < LONG_MAX - 3 * DAY_SEC))
 177     {
 178         std::unique_ptr<icu::TimeZone> pLocalZone(icu::TimeZone::createDefault());
 179         tools::Long offset = (pLocalZone->getRawOffset()) / 1000;
 180         pLocalZone.reset();
 181         tools::Long ltime = rtime + offset;
 182         return LtgGmTime(ltime, rtm);
 183     }
 184     return false;
 185 };
 186
 187 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */