wtf/DateMath.h

   1 /*
   2  * Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
   3  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
   4  * Copyright (C) 2009 Google Inc. All rights reserved.
   5  *
   6  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   7  *
   8  * The contents of this file are subject to the Mozilla Public License Version
   9  * 1.1 (the "License"); you may not use this file except in compliance with
  10  * the License. You may obtain a copy of the License at
  11  * http://www.mozilla.org/MPL/
  12  *
  13  * Software distributed under the License is distributed on an "AS IS" basis,
  14  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  15  * for the specific language governing rights and limitations under the
  16  * License.
  17  *
  18  * The Original Code is Mozilla Communicator client code, released
  19  * March 31, 1998.
  20  *
  21  * The Initial Developer of the Original Code is
  22  * Netscape Communications Corporation.
  23  * Portions created by the Initial Developer are Copyright (C) 1998
  24  * the Initial Developer. All Rights Reserved.
  25  *
  26  * Contributor(s):
  27  *
  28  * Alternatively, the contents of this file may be used under the terms of
  29  * either of the GNU General Public License Version 2 or later (the "GPL"),
  30  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  31  * in which case the provisions of the GPL or the LGPL are applicable instead
  32  * of those above. If you wish to allow use of your version of this file only
  33  * under the terms of either the GPL or the LGPL, and not to allow others to
  34  * use your version of this file under the terms of the MPL, indicate your
  35  * decision by deleting the provisions above and replace them with the notice
  36  * and other provisions required by the GPL or the LGPL. If you do not delete
  37  * the provisions above, a recipient may use your version of this file under
  38  * the terms of any one of the MPL, the GPL or the LGPL.
  39  *
  40  */
  41
  42 #ifndef DateMath_h
  43 #define DateMath_h
  44
  45 #include <time.h>
  46 #include <string.h>
  47 #include <wtf/Noncopyable.h>
  48
  49 namespace WTF {
  50
  51 struct GregorianDateTime;
  52
  53 void initializeDates();
  54 void msToGregorianDateTime(double, bool outputIsUTC, GregorianDateTime&);
  55 double gregorianDateTimeToMS(const GregorianDateTime&, double, bool inputIsUTC);
  56 double getUTCOffset();
  57 int equivalentYearForDST(int year);
  58 double getCurrentUTCTime();
  59 double getCurrentUTCTimeWithMicroseconds();
  60 void getLocalTime(const time_t*, tm*);
  61
  62 // Not really math related, but this is currently the only shared place to put these.
  63 double parseDateFromNullTerminatedCharacters(const char*);
  64 double timeClip(double);
  65
  66 const char * const weekdayName[7] = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };
  67 const char * const monthName[12] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
  68
  69 const double hoursPerDay = 24.0;
  70 const double minutesPerHour = 60.0;
  71 const double secondsPerHour = 60.0 * 60.0;
  72 const double secondsPerMinute = 60.0;
  73 const double msPerSecond = 1000.0;
  74 const double msPerMinute = 60.0 * 1000.0;
  75 const double msPerHour = 60.0 * 60.0 * 1000.0;
  76 const double msPerDay = 24.0 * 60.0 * 60.0 * 1000.0;
  77
  78 // Intentionally overridding the default tm of the system
  79 // Tee members of tm differ on various operating systems.
  80 struct GregorianDateTime : Noncopyable {
  81     GregorianDateTime()
  82         : second(0)
  83         , minute(0)
  84         , hour(0)
  85         , weekDay(0)
  86         , monthDay(0)
  87         , yearDay(0)
  88         , month(0)
  89         , year(0)
  90         , isDST(0)
  91         , utcOffset(0)
  92         , timeZone(0)
  93     {
  94     }
  95
  96     ~GregorianDateTime()
  97     {
  98         delete [] timeZone;
  99     }
 100
 101     GregorianDateTime(const tm& inTm)
 102         : second(inTm.tm_sec)
 103         , minute(inTm.tm_min)
 104         , hour(inTm.tm_hour)
 105         , weekDay(inTm.tm_wday)
 106         , monthDay(inTm.tm_mday)
 107         , yearDay(inTm.tm_yday)
 108         , month(inTm.tm_mon)
 109         , year(inTm.tm_year)
 110         , isDST(inTm.tm_isdst)
 111     {
 112 #if !PLATFORM(WIN_OS) && !PLATFORM(SOLARIS) && !COMPILER(RVCT)
 113         utcOffset = static_cast<int>(inTm.tm_gmtoff);
 114
 115         int inZoneSize = strlen(inTm.tm_zone) + 1;
 116         timeZone = new char[inZoneSize];
 117         strncpy(timeZone, inTm.tm_zone, inZoneSize);
 118 #else
 119         utcOffset = static_cast<int>(getUTCOffset() / msPerSecond + (isDST ? secondsPerHour : 0));
 120         timeZone = 0;
 121 #endif
 122     }
 123
 124     operator tm() const
 125     {
 126         tm ret;
 127         memset(&ret, 0, sizeof(ret));
 128
 129         ret.tm_sec   =  second;
 130         ret.tm_min   =  minute;
 131         ret.tm_hour  =  hour;
 132         ret.tm_wday  =  weekDay;
 133         ret.tm_mday  =  monthDay;
 134         ret.tm_yday  =  yearDay;
 135         ret.tm_mon   =  month;
 136         ret.tm_year  =  year;
 137         ret.tm_isdst =  isDST;
 138
 139 #if !PLATFORM(WIN_OS) && !PLATFORM(SOLARIS) && !COMPILER(RVCT)
 140         ret.tm_gmtoff = static_cast<long>(utcOffset);
 141         ret.tm_zone = timeZone;
 142 #endif
 143
 144         return ret;
 145     }
 146
 147     void copyFrom(const GregorianDateTime& rhs)
 148     {
 149         second = rhs.second;
 150         minute = rhs.minute;
 151         hour = rhs.hour;
 152         weekDay = rhs.weekDay;
 153         monthDay = rhs.monthDay;
 154         yearDay = rhs.yearDay;
 155         month = rhs.month;
 156         year = rhs.year;
 157         isDST = rhs.isDST;
 158         utcOffset = rhs.utcOffset;
 159         if (rhs.timeZone) {
 160             int inZoneSize = strlen(rhs.timeZone) + 1;
 161             timeZone = new char[inZoneSize];
 162             strncpy(timeZone, rhs.timeZone, inZoneSize);
 163         } else
 164             timeZone = 0;
 165     }
 166
 167     int second;
 168     int minute;
 169     int hour;
 170     int weekDay;
 171     int monthDay;
 172     int yearDay;
 173     int month;
 174     int year;
 175     int isDST;
 176     int utcOffset;
 177     char* timeZone;
 178 };
 179
 180 static inline int gmtoffset(const GregorianDateTime& t)
 181 {
 182     return t.utcOffset;
 183 }
 184
 185 } // namespace WTF
 186
 187 #endif // DateMath_h