src/time.h

   1 ///
   2 /// \file       time.h
   3 ///             Conversion between time_t and cenmin_t and back.
   4 ///             time_t is the POSIX time.
   5 ///             min1900_t is the minutes from Jan 1, 1900
   6 ///
   7
   8 /*
   9     Copyright (C) 2005-2008, Net Direct Inc. (http://www.netdirect.ca/)
  10
  11     This program is free software; you can redistribute it and/or modify
  12     it under the terms of the GNU General Public License as published by
  13     the Free Software Foundation; either version 2 of the License, or
  14     (at your option) any later version.
  15
  16     This program is distributed in the hope that it will be useful,
  17     but WITHOUT ANY WARRANTY; without even the implied warranty of
  18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  19
  20     See the GNU General Public License in the COPYING file at the
  21     root directory of this project for more details.
  22 */
  23
  24 #ifndef __BARRY_TIME_H__
  25 #define __BARRY_TIME_H__
  26
  27 #include "dll.h"
  28 #include <time.h>
  29 #include <stdint.h>
  30
  31 //
  32 // Calculate the number of minutes between Jan 01, 1900 and Jan 01, 1970
  33 //
  34 // There are 17 leap years between 1900 and 1970
  35 //    (1969-1900) / 4 = 17.25
  36 //
  37 // 1900 itself is not a leap year (not divisible by 400)
  38 //
  39 #define DAY_MINUTES (24 * 60)
  40 #define YEAR_MINUTES (365 * DAY_MINUTES)
  41 #define LEAP_YEAR_COUNT ((1970-1901) / 4)
  42 #define YEAR_COUNT (1970 - 1900)
  43
  44 // therefore, the difference between standard C's time and min1900_t's
  45 // time in minutes:
  46 #define STDC_MIN1900_DIFF (YEAR_COUNT * YEAR_MINUTES + LEAP_YEAR_COUNT * DAY_MINUTES)
  47
  48 namespace Barry {
  49
  50 typedef long min1900_t;
  51
  52 BXEXPORT min1900_t time2min(time_t t);
  53 BXEXPORT time_t min2time(min1900_t m);
  54
  55 // FIXME - turn TimeZone into a C typedef and wrap this in extern "C"
  56 // so the data can be used in both C and C++ libraries
  57 struct BXEXPORT TimeZone
  58 {
  59         unsigned short Code;
  60         signed short HourOffset;
  61         signed short MinOffset;
  62         const char *Name;
  63 };
  64
  65 // FIXME - put this somewhere for both C and C++
  66 #define TIME_ZONE_CODE_ERR      0xffff
  67
  68 BXEXPORT const TimeZone* GetTimeZoneTable();
  69 BXEXPORT const TimeZone* GetTimeZone(unsigned short Code);
  70 BXEXPORT unsigned short GetTimeZoneCode(signed short HourOffset,
  71         signed short MinOffset = 0);
  72
  73 // Message time conversion stuff
  74 BXEXPORT time_t DayToDate( unsigned short Day );
  75 BXEXPORT time_t Message2Time(uint16_t r_date, uint16_t r_time);
  76
  77 } // namespace Barry
  78
  79 #endif
  80