X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/fcc3d7cbadcd59d6a2cafafc32624e8a22af0e56..41b1047d910c3aba988b5b619ba885b7ac89cf20:/src/common/datetime.cpp diff --git a/src/common/datetime.cpp b/src/common/datetime.cpp index 901156a569..d93cb2d179 100644 --- a/src/common/datetime.cpp +++ b/src/common/datetime.cpp @@ -1,13 +1,48 @@ -///////////////////////////////////////////////////////////////////////////// +/////////////////////////////////////////////////////////////////////////////// // Name: wx/datetime.h // Purpose: implementation of time/date related classes // Author: Vadim Zeitlin // Modified by: // Created: 11.05.99 // RCS-ID: $Id$ -// Copyright: (c) 1998 Vadim Zeitlin +// Copyright: (c) 1999 Vadim Zeitlin +// parts of code taken from sndcal library by Scott E. Lee: +// +// Copyright 1993-1995, Scott E. Lee, all rights reserved. +// Permission granted to use, copy, modify, distribute and sell +// so long as the above copyright and this permission statement +// are retained in all copies. +// // Licence: wxWindows license -///////////////////////////////////////////////////////////////////////////// +/////////////////////////////////////////////////////////////////////////////// + +/* + * Implementation notes: + * + * 1. the time is stored as a 64bit integer containing the signed number of + * milliseconds since Jan 1. 1970 (the Unix Epoch) - so it is always + * expressed in GMT. + * + * 2. the range is thus something about 580 million years, but due to current + * algorithms limitations, only dates from Nov 24, 4714BC are handled + * + * 3. standard ANSI C functions are used to do time calculations whenever + * possible, i.e. when the date is in the range Jan 1, 1970 to 2038 + * + * 4. otherwise, the calculations are done by converting the date to/from JDN + * first (the range limitation mentioned above comes from here: the + * algorithm used by Scott E. Lee's code only works for positive JDNs, more + * or less) + * + * 5. the object constructed for the given DD-MM-YYYY HH:MM:SS corresponds to + * this moment in local time and may be converted to the object + * corresponding to the same date/time in another time zone by using + * ToTimezone() + * + * 6. the conversions to the current (or any other) timezone are done when the + * internal time representation is converted to the broken-down one in + * wxDateTime::Tm. + */ // ============================================================================ // declarations @@ -44,19 +79,30 @@ // constants // ---------------------------------------------------------------------------- -// note that all these constants should be signed or we'd get some big -// surprizes with C integer arithmetics +// some trivial ones static const int MONTHS_IN_YEAR = 12; static const int SECONDS_IN_MINUTE = 60; -// the number of days in month in Julian/Gregorian calendar: the first line is -// for normal years, the second one is for the leap ones -static wxDateTime::wxDateTime_t gs_daysInMonth[2][MONTHS_IN_YEAR] = -{ - { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, - { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } -}; +static const long SECONDS_PER_DAY = 86400l; + +static const long MILLISECONDS_PER_DAY = 86400000l; + +// this is the integral part of JDN of the midnight of Jan 1, 1970 +// (i.e. JDN(Jan 1, 1970) = 2440587.5) +static const int EPOCH_JDN = 2440587; + +// the date of JDN -0.5 (as we don't work with fractional parts, this is the +// reference date for us) is Nov 24, 4714BC +static const int JDN_0_YEAR = -4713; +static const int JDN_0_MONTH = wxDateTime::Nov; +static const int JDN_0_DAY = 24; + +// the constants used for JDN calculations +static const int JDN_OFFSET = 32046; +static const int DAYS_PER_5_MONTHS = 153; +static const int DAYS_PER_4_YEARS = 1461; +static const int DAYS_PER_400_YEARS = 146097; // ---------------------------------------------------------------------------- // globals @@ -76,7 +122,15 @@ static wxDateTime::wxDateTime_t gs_daysInMonth[2][MONTHS_IN_YEAR] = static inline wxDateTime::wxDateTime_t GetNumOfDaysInMonth(int year, wxDateTime::Month month) { - return gs_daysInMonth[wxDateTime::IsLeapYear(year)][month]; + // the number of days in month in Julian/Gregorian calendar: the first line + // is for normal years, the second one is for the leap ones + static wxDateTime::wxDateTime_t daysInMonth[2][MONTHS_IN_YEAR] = + { + { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, + { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } + }; + + return daysInMonth[wxDateTime::IsLeapYear(year)][month]; } // ensure that the timezone variable is set by calling localtime @@ -89,7 +143,10 @@ static int GetTimeZone() if ( !s_timezoneSet ) { - (void)localtime(0); + // just call localtime() instead of figuring out whether this system + // supports tzset(), _tzset() or something else + time_t t; + (void)localtime(&t); s_timezoneSet = TRUE; } @@ -97,6 +154,46 @@ static int GetTimeZone() return (int)timezone; } +// return the integral part of the JDN for the midnight of the given date (to +// get the real JDN you need to add 0.5, this is, in fact, JDN of the +// noon of the previous day) +static long GetTruncatedJDN(wxDateTime::wxDateTime_t day, + wxDateTime::Month mon, + int year) +{ + // CREDIT: code below is by Scott E. Lee (but bugs are mine) + + // check the date validity + wxASSERT_MSG( + (year > JDN_0_YEAR) || + ((year == JDN_0_YEAR) && (mon > JDN_0_MONTH)) || + ((year == JDN_0_YEAR) && (mon == JDN_0_MONTH) && (day >= JDN_0_DAY)), + _T("date out of range - can't convert to JDN") + ); + + // make the year positive to avoid problems with negative numbers division + year += 4800; + + // months are counted from March here + int month; + if ( mon >= wxDateTime::Mar ) + { + month = mon - 2; + } + else + { + month = mon + 10; + year--; + } + + // now we can simply add all the contributions together + return ((year / 100) * DAYS_PER_400_YEARS) / 4 + + ((year % 100) * DAYS_PER_4_YEARS) / 4 + + (month * DAYS_PER_5_MONTHS + 2) / 5 + + day + - JDN_OFFSET; +} + // this function is a wrapper around strftime(3) static wxString CallStrftime(const wxChar *format, const tm* tm) { @@ -152,12 +249,14 @@ wxDateTime::Tm::Tm() year = (wxDateTime_t)wxDateTime::Inv_Year; mon = wxDateTime::Inv_Month; mday = 0; - hour = min = sec = 0; + hour = min = sec = msec = 0; wday = wxDateTime::Inv_WeekDay; } -wxDateTime::Tm::Tm(const struct tm& tm) +wxDateTime::Tm::Tm(const struct tm& tm, const TimeZone& tz) + : m_tz(tz) { + msec = 0; sec = tm.tm_sec; min = tm.tm_min; hour = tm.tm_hour; @@ -173,7 +272,7 @@ bool wxDateTime::Tm::IsValid() const // we allow for the leap seconds, although we don't use them (yet) return (year != wxDateTime::Inv_Year) && (mon != wxDateTime::Inv_Month) && (mday < GetNumOfDaysInMonth(year, mon)) && - (hour < 24) && (min < 60) && (sec < 62); + (hour < 24) && (min < 60) && (sec < 62) && (msec < 1000); } void wxDateTime::Tm::ComputeWeekDay() @@ -181,7 +280,7 @@ void wxDateTime::Tm::ComputeWeekDay() wxFAIL_MSG(_T("TODO")); } -void wxDateTime::Tm::AddMonths(wxDateTime::wxDateTime_t monDiff) +void wxDateTime::Tm::AddMonths(int monDiff) { // normalize the months field while ( monDiff < -mon ) @@ -198,10 +297,10 @@ void wxDateTime::Tm::AddMonths(wxDateTime::wxDateTime_t monDiff) mon = (wxDateTime::Month)(mon + monDiff); - wxASSERT_MSG( mon >= 0 && mon < 12, _T("logic error") ); + wxASSERT_MSG( mon >= 0 && mon < MONTHS_IN_YEAR, _T("logic error") ); } -void wxDateTime::Tm::AddDays(wxDateTime::wxDateTime_t dayDiff) +void wxDateTime::Tm::AddDays(int dayDiff) { // normalize the days field mday += dayDiff; @@ -232,7 +331,9 @@ wxDateTime::TimeZone::TimeZone(wxDateTime::TZ tz) switch ( tz ) { case wxDateTime::Local: - // leave offset to be 0 + // get the offset from C RTL: it returns the difference GMT-local + // while we want to have the offset _from_ GMT, hence the '-' + m_offset = -GetTimeZone(); break; case wxDateTime::GMT_12: @@ -247,7 +348,7 @@ wxDateTime::TimeZone::TimeZone(wxDateTime::TZ tz) case wxDateTime::GMT_3: case wxDateTime::GMT_2: case wxDateTime::GMT_1: - m_offset = -60*(wxDateTime::GMT0 - tz); + m_offset = -3600*(wxDateTime::GMT0 - tz); break; case wxDateTime::GMT0: @@ -263,12 +364,12 @@ wxDateTime::TimeZone::TimeZone(wxDateTime::TZ tz) case wxDateTime::GMT10: case wxDateTime::GMT11: case wxDateTime::GMT12: - m_offset = 60*(tz - wxDateTime::GMT0); + m_offset = 3600*(tz - wxDateTime::GMT0); break; case wxDateTime::A_CST: // Central Standard Time in use in Australia = UTC + 9.5 - m_offset = 9*60 + 30; + m_offset = 60*(9*60 + 30); break; default: @@ -434,7 +535,7 @@ wxString wxDateTime::GetWeekDayName(wxDateTime::WeekDay wday, bool abbr) // take some arbitrary Sunday tm tm = { 0, 0, 0, 28, Nov, 99 }; - // and offset it by the number of days needed to get + // and offset it by the number of days needed to get the correct wday tm.tm_mday += wday; return CallStrftime(abbr ? _T("%a") : _T("%A"), &tm); @@ -444,15 +545,33 @@ wxString wxDateTime::GetWeekDayName(wxDateTime::WeekDay wday, bool abbr) // constructors and assignment operators // ---------------------------------------------------------------------------- -wxDateTime& wxDateTime::Set(const struct tm& tm1) +// the values in the tm structure contain the local time +wxDateTime& wxDateTime::Set(const struct tm& tm) { wxASSERT_MSG( IsValid(), _T("invalid wxDateTime") ); - tm tm2(tm1); + struct tm tm2(tm); time_t timet = mktime(&tm2); - if ( timet == (time_t)(-1) ) + + if ( timet == (time_t)-1 ) { - wxFAIL_MSG(_T("Invalid time")); + // mktime() rather unintuitively fails for Jan 1, 1970 if the hour is + // less than timezone - try to make it work for this case + if ( tm2.tm_year == 70 && tm2.tm_mon == 0 && tm2.tm_mday == 1 ) + { + // add timezone to make sure that date is in range + tm2.tm_sec -= GetTimeZone(); + + timet = mktime(&tm2); + if ( timet != (time_t)-1 ) + { + timet += GetTimeZone(); + + return Set(timet); + } + } + + wxFAIL_MSG( _T("mktime() failed") ); return ms_InvDateTime; } @@ -479,6 +598,8 @@ wxDateTime& wxDateTime::Set(wxDateTime_t hour, time_t timet = GetTimeNow(); struct tm *tm = localtime(&timet); + wxCHECK_MSG( tm, ms_InvDateTime, _T("localtime() failed") ); + // adjust the time tm->tm_hour = hour; tm->tm_min = minute; @@ -506,7 +627,8 @@ wxDateTime& wxDateTime::Set(wxDateTime_t day, ReplaceDefaultYearMonthWithCurrent(&year, &month); - wxCHECK_MSG( day <= GetNumberOfDays(month, year), ms_InvDateTime, + wxCHECK_MSG( (0 < day) && (day <= GetNumberOfDays(month, year)), + ms_InvDateTime, _T("Invalid date in wxDateTime::Set()") ); // the range of time_t type (inclusive) @@ -526,6 +648,7 @@ wxDateTime& wxDateTime::Set(wxDateTime_t day, tm.tm_hour = hour; tm.tm_min = minute; tm.tm_sec = second; + tm.tm_isdst = -1; // mktime() will guess it (void)Set(tm); @@ -536,17 +659,36 @@ wxDateTime& wxDateTime::Set(wxDateTime_t day, { // do time calculations ourselves: we want to calculate the number of // milliseconds between the given date and the epoch - wxFAIL_MSG(_T("TODO")); + + // get the JDN for the midnight of this day + m_time = GetTruncatedJDN(day, month, year); + m_time -= EPOCH_JDN; + m_time *= SECONDS_PER_DAY * TIME_T_FACTOR; + + // JDN corresponds to GMT, we take localtime + Add(wxTimeSpan(hour, minute, second + GetTimeZone(), millisec)); } return *this; } +wxDateTime& wxDateTime::Set(double jdn) +{ + // so that m_time will be 0 for the midnight of Jan 1, 1970 which is jdn + // EPOCH_JDN + 0.5 + jdn -= EPOCH_JDN + 0.5; + + m_time = jdn; + m_time *= MILLISECONDS_PER_DAY; + + return *this; +} + // ---------------------------------------------------------------------------- // time_t <-> broken down time conversions // ---------------------------------------------------------------------------- -wxDateTime::Tm wxDateTime::GetTm() const +wxDateTime::Tm wxDateTime::GetTm(const TimeZone& tz) const { wxASSERT_MSG( IsValid(), _T("invalid wxDateTime") ); @@ -554,18 +696,104 @@ wxDateTime::Tm wxDateTime::GetTm() const if ( time != (time_t)-1 ) { // use C RTL functions - tm *tm = localtime(&time); + tm *tm; + if ( tz.GetOffset() == -GetTimeZone() ) + { + // we are working with local time + tm = localtime(&time); + } + else + { + time += tz.GetOffset(); + tm = gmtime(&time); + } // should never happen - wxCHECK_MSG( tm, Tm(), _T("localtime() failed") ); + wxCHECK_MSG( tm, Tm(), _T("gmtime() failed") ); - return Tm(*tm); + return Tm(*tm, tz); } else { - wxFAIL_MSG(_T("TODO")); + // remember the time and do the calculations with the date only - this + // eliminates rounding errors of the floating point arithmetics + + wxLongLong timeMidnight = m_time + tz.GetOffset() * 1000; + + long timeOnly = (timeMidnight % MILLISECONDS_PER_DAY).ToLong(); + + // we want to always have positive time and timeMidnight to be really + // the midnight before it + if ( timeOnly < 0 ) + { + timeOnly = MILLISECONDS_PER_DAY + timeOnly; + } + + timeMidnight -= timeOnly; + + // calculate the Gregorian date from JDN for the midnight of our date: + // this will yield day, month (in 1..12 range) and year + + // actually, this is the JDN for the noon of the previous day + long jdn = (timeMidnight / MILLISECONDS_PER_DAY).ToLong() + EPOCH_JDN; + + // CREDIT: code below is by Scott E. Lee (but bugs are mine) + + wxASSERT_MSG( jdn > -2, _T("JDN out of range") ); + + // calculate the century + int temp = (jdn + JDN_OFFSET) * 4 - 1; + int century = temp / DAYS_PER_400_YEARS; + + // then the year and day of year (1 <= dayOfYear <= 366) + temp = ((temp % DAYS_PER_400_YEARS) / 4) * 4 + 3; + int year = (century * 100) + (temp / DAYS_PER_4_YEARS); + int dayOfYear = (temp % DAYS_PER_4_YEARS) / 4 + 1; + + // and finally the month and day of the month + temp = dayOfYear * 5 - 3; + int month = temp / DAYS_PER_5_MONTHS; + int day = (temp % DAYS_PER_5_MONTHS) / 5 + 1; + + // month is counted from March - convert to normal + if ( month < 10 ) + { + month += 3; + } + else + { + year += 1; + month -= 9; + } + + // year is offset by 4800 + year -= 4800; + + // check that the algorithm gave us something reasonable + wxASSERT_MSG( (0 < month) && (month <= 12), _T("invalid month") ); + wxASSERT_MSG( (1 <= day) && (day < 32), _T("invalid day") ); + wxASSERT_MSG( (INT_MIN <= year) && (year <= INT_MAX), + _T("year range overflow") ); + + // construct Tm from these values + Tm tm; + tm.year = (int)year; + tm.mon = (Month)(month - 1); // algorithm yields 1 for January, not 0 + tm.mday = (wxDateTime_t)day; + tm.msec = timeOnly % 1000; + timeOnly -= tm.msec; + timeOnly /= 1000; // now we have time in seconds + + tm.sec = timeOnly % 60; + timeOnly -= tm.sec; + timeOnly /= 60; // now we have time in minutes - return Tm(); + tm.min = timeOnly % 60; + timeOnly -= tm.min; + + tm.hour = timeOnly / 60; + + return tm; } } @@ -745,48 +973,144 @@ bool wxDateTime::SetToWeekDay(WeekDay weekday, } // ---------------------------------------------------------------------------- -// timezone stuff +// Julian day number conversion and related stuff // ---------------------------------------------------------------------------- -wxDateTime& wxDateTime::MakeUTC() +double wxDateTime::GetJulianDayNumber() const { - return Add(wxTimeSpan::Seconds(GetTimeZone())); + // JDN are always expressed for the GMT dates + Tm tm(ToTimezone(GMT0).GetTm(GMT0)); + + double result = GetTruncatedJDN(tm.mday, tm.mon, tm.year); + + // add the part GetTruncatedJDN() neglected + result += 0.5; + + // and now add the time: 86400 sec = 1 JDN + return result + ((double)(60*(60*tm.hour + tm.min) + tm.sec)) / 86400; } -wxDateTime& wxDateTime::MakeTimezone(const TimeZone& tz) +double wxDateTime::GetRataDie() const { - int minDiff = GetTimeZone() / SECONDS_IN_MINUTE + tz.GetOffset(); - return Add(wxTimeSpan::Minutes(minDiff)); + // March 1 of the year 0 is Rata Die day -306 and JDN 1721119.5 + return GetJulianDayNumber() - 1721119.5 - 306; +} + +// ---------------------------------------------------------------------------- +// timezone and DST stuff +// ---------------------------------------------------------------------------- + +int wxDateTime::IsDST(wxDateTime::Country country) const +{ + wxCHECK_MSG( country == Country_Default, -1, + _T("country support not implemented") ); + + // use the C RTL for the dates in the standard range + time_t timet = GetTicks(); + if ( timet != (time_t)-1 ) + { + tm *tm = localtime(&timet); + + wxCHECK_MSG( tm, -1, _T("localtime() failed") ); + + return tm->tm_isdst; + } + else + { + // wxFAIL_MSG( _T("TODO") ); + + return -1; + } } -wxDateTime& wxDateTime::MakeLocalTime(const TimeZone& tz) +wxDateTime& wxDateTime::MakeTimezone(const TimeZone& tz) { - int minDiff = GetTimeZone() / SECONDS_IN_MINUTE + tz.GetOffset(); - return Substract(wxTimeSpan::Minutes(minDiff)); + int secDiff = GetTimeZone() + tz.GetOffset(); + + // we need to know whether DST is or not in effect for this date + if ( IsDST() == 1 ) + { + // FIXME we assume that the DST is always shifted by 1 hour + secDiff -= 3600; + } + + return Substract(wxTimeSpan::Seconds(secDiff)); } // ---------------------------------------------------------------------------- // wxDateTime to/from text representations // ---------------------------------------------------------------------------- -wxString wxDateTime::Format(const wxChar *format) const +wxString wxDateTime::Format(const wxChar *format, const TimeZone& tz) const { + wxCHECK_MSG( format, _T(""), _T("NULL format in wxDateTime::Format") ); + time_t time = GetTicks(); if ( time != (time_t)-1 ) { // use strftime() - tm *tm = localtime(&time); + tm *tm; + if ( tz.GetOffset() == -GetTimeZone() ) + { + // we are working with local time + tm = localtime(&time); + } + else + { + time += tz.GetOffset(); + + tm = gmtime(&time); + } // should never happen - wxCHECK_MSG( tm, _T(""), _T("localtime() failed") ); + wxCHECK_MSG( tm, _T(""), _T("gmtime() failed") ); return CallStrftime(format, tm); } else { - wxFAIL_MSG(_T("TODO")); + // use a hack and still use strftime(): make a copy of the format and + // replace all occurences of YEAR in it with some unique string not + // appearing anywhere else in it, then use strftime() to format the + // date in year YEAR and then replace YEAR back by the real year and + // the unique replacement string back with YEAR where YEAR is any year + // in the range supported by strftime() (1970 - 2037) which is equal to + // the real year modulo 28 (so the week days coincide for them) + + // find the YEAR + int yearReal = GetYear(tz); + int year = 1970 + yearReal % 28; + + wxString strYear; + strYear.Printf(_T("%d"), year); + + // find a string not occuring in format (this is surely not optimal way + // of doing it... improvements welcome!) + wxString fmt = format; + wxString replacement = (wxChar)-1; + while ( fmt.Find(replacement) != wxNOT_FOUND ) + { + replacement << (wxChar)-1; + } + + // replace all occurences of year with it + bool wasReplaced = fmt.Replace(strYear, replacement) > 0; + + // use strftime() to format the same date but in supported year + wxDateTime dt(*this); + dt.SetYear(year); + wxString str = dt.Format(format, tz); - return _T(""); + // now replace the occurence of 1999 with the real year + wxString strYearReal; + strYearReal.Printf(_T("%d"), yearReal); + str.Replace(strYear, strYearReal); + + // and replace back all occurences of replacement string + if ( wasReplaced ) + str.Replace(replacement, strYear); + + return str; } } @@ -794,11 +1118,84 @@ wxString wxDateTime::Format(const wxChar *format) const // wxTimeSpan // ============================================================================ +// not all strftime(3) format specifiers make sense here because, for example, +// a time span doesn't have a year nor a timezone +// +// Here are the ones which are supported (all of them are supported by strftime +// as well): +// %H hour in 24 hour format +// %M minute (00 - 59) +// %S second (00 - 59) +// %% percent sign +// +// Also, for MFC CTimeSpan compatibility, we support +// %D number of days +// +// And, to be better than MFC :-), we also have +// %E number of wEeks +// %l milliseconds (000 - 999) wxString wxTimeSpan::Format(const wxChar *format) const { - wxFAIL_MSG( _T("TODO") ); + wxCHECK_MSG( format, _T(""), _T("NULL format in wxTimeSpan::Format") ); wxString str; + str.Alloc(strlen(format)); + + for ( const wxChar *pch = format; pch; pch++ ) + { + wxChar ch = *pch; + + if ( ch == '%' ) + { + wxString tmp; + + ch = *pch++; + switch ( ch ) + { + default: + wxFAIL_MSG( _T("invalid format character") ); + // fall through + + case '%': + // will get to str << ch below + break; + + case 'D': + tmp.Printf(_T("%d"), GetDays()); + break; + + case 'E': + tmp.Printf(_T("%d"), GetWeeks()); + break; + + case 'H': + tmp.Printf(_T("%02d"), GetHours()); + break; + + case 'l': + tmp.Printf(_T("%03d"), GetMilliseconds()); + break; + + case 'M': + tmp.Printf(_T("%02d"), GetMinutes()); + break; + + case 'S': + tmp.Printf(_T("%02d"), GetSeconds()); + break; + } + + if ( !!tmp ) + { + str += tmp; + + // skip str += ch below + continue; + } + } + + str += ch; + } return str; }