From 1ef54dcf125ad687ccfd32195fe2f449910e7d5f Mon Sep 17 00:00:00 2001 From: Vadim Zeitlin Date: Fri, 3 Dec 1999 21:27:57 +0000 Subject: [PATCH] wxDateTime... git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@4811 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775 --- include/wx/datetime.h | 2 +- include/wx/longlong.h | 15 +++ samples/console/console.cpp | 68 +++++++++-- src/common/datetime.cpp | 219 ++++++++++++++++++++++++++---------- 4 files changed, 229 insertions(+), 75 deletions(-) diff --git a/include/wx/datetime.h b/include/wx/datetime.h index 30a7ef4c76..23909f3d61 100644 --- a/include/wx/datetime.h +++ b/include/wx/datetime.h @@ -780,7 +780,7 @@ public: static struct tm *GetTmNow() { time_t t = GetTimeNow(); - return localtime(&t); + return gmtime(&t); } private: diff --git a/include/wx/longlong.h b/include/wx/longlong.h index 74114fc9a2..1e5ee03100 100644 --- a/include/wx/longlong.h +++ b/include/wx/longlong.h @@ -19,6 +19,12 @@ #pragma interface "longlong.h" #endif +#include "wx/defs.h" +#include "wx/wxchar.h" +#include "wx/debug.h" + +#include // for LONG_MAX + // ---------------------------------------------------------------------------- // decide upon which class we will use // ---------------------------------------------------------------------------- @@ -124,6 +130,15 @@ public: // convert to native long long wxLongLong_t GetValue() const { return m_ll; } + // convert to long with range checking in the debug mode (only!) + long ToLong() const + { + wxASSERT_MSG( (m_ll >= LONG_MIN) && (m_ll <= LONG_MAX), + _T("wxLongLong to long conversion loss of precision") ); + + return (long)m_ll; + } + // don't provide implicit conversion to wxLongLong_t or we will have an // ambiguity for all arithmetic operations //operator wxLongLong_t() const { return m_ll; } diff --git a/samples/console/console.cpp b/samples/console/console.cpp index f4d887f987..981a302ac3 100644 --- a/samples/console/console.cpp +++ b/samples/console/console.cpp @@ -32,8 +32,8 @@ //#define TEST_ARRAYS //#define TEST_LOG //#define TEST_STRINGS -#define TEST_THREADS -//#define TEST_TIME +//#define TEST_THREADS +#define TEST_TIME //#define TEST_LONGLONG // ============================================================================ @@ -187,7 +187,7 @@ static void TestTimeZones() wxDateTime now = wxDateTime::Now(); printf("Current GMT time:\t%s\n", now.ToGMT().Format().c_str()); - //TODO printf("Unix epoch (GMT):\t%s\n", wxDateTime((time_t)0).MakeGMT().Format().c_str()); + printf("Unix epoch (GMT):\t%s\n", wxDateTime((time_t)0).MakeGMT().Format().c_str()); printf("Current time in Paris:\t%s\n", now.ToTimezone(wxDateTime::CET).Format().c_str()); printf(" Moscow:\t%s\n", now.ToTimezone(wxDateTime::MSK).Format().c_str()); printf(" New York:\t%s\n", now.ToTimezone(wxDateTime::EST).Format().c_str()); @@ -198,6 +198,10 @@ static void TestTimeRange() { puts("\n*** wxDateTime out-of-standard-range dates test ***"); + printf("Unix epoch:\t%s\n", + wxDateTime(2440587.5).Format().c_str()); + printf("Feb 29, 0: \t%s\n", + wxDateTime(29, wxDateTime::Feb, 0).Format().c_str()); printf("JDN 0: \t%s\n", wxDateTime(0.0).Format().c_str()); printf("Jan 1, 1AD:\t%s\n", @@ -207,17 +211,57 @@ static void TestTimeRange() } // test conversions to JDN &c -static void TestTimeJulian() +static void TestTimeJDN() { puts("\n*** wxDateTime to JDN test ***"); - printf("JDN of current time:\t%f\n", wxDateTime::Now().GetJulianDayNumber()); - printf("JDN of Jan 1, 1900: \t%f\n", - wxDateTime(1, wxDateTime::Jan, 1900).GetJulianDayNumber()); - printf("JDN of Jan 1, 1BC: \t%f\n", - wxDateTime(1, wxDateTime::Jan, 0).GetJulianDayNumber()); - printf("JDN 0: \t%f\n", - wxDateTime(24, wxDateTime::Nov, -4713, 12, 0, 0).GetJulianDayNumber()); + struct Date + { + wxDateTime::wxDateTime_t day; + wxDateTime::Month month; + int year; + double jdn; + }; + + static const Date testDates[] = + { + { 21, wxDateTime::Jan, 2222, 2532648.5 }, + { 29, wxDateTime::May, 1976, 2442927.5 }, + { 1, wxDateTime::Jan, 1970, 2440587.5 }, + { 1, wxDateTime::Jan, 1900, 2415020.5 }, + { 15, wxDateTime::Oct, 1582, 2299160.5 }, + { 4, wxDateTime::Oct, 1582, 2299149.5 }, + { 1, wxDateTime::Mar, 1, 1721484.5 }, + { 1, wxDateTime::Jan, 1, 1721425.5 }, + { 31, wxDateTime::Dec, 0, 1721424.5 }, + { 1, wxDateTime::Jan, 0, 1721059.5 }, + { 12, wxDateTime::Aug, -1234, 1270573.5 }, + { 12, wxDateTime::Aug, -4000, 260313.5 }, + { 24, wxDateTime::Nov, -4713, -0.5 }, + }; + + for ( size_t n = 0; n < WXSIZEOF(testDates); n++ ) + { + const Date& d = testDates[n]; + wxDateTime dt(d.day, d.month, d.year); + double jdn = dt.GetJulianDayNumber(); + + printf("JDN of %s %02d, %4d%s is:\t%f", + wxDateTime::GetMonthName(d.month).c_str(), + d.day, + wxDateTime::ConvertYearToBC(d.year), + d.year > 0 ? "AD" : "BC", + jdn); + if ( jdn == d.jdn ) + { + puts(" (ok)"); + } + else + { + printf(" (ERROR: should be %f, delta = %f)\n", + d.jdn, jdn - d.jdn); + } + } } #endif // TEST_TIME @@ -629,7 +673,7 @@ int main(int argc, char **argv) TestTimeSet(); TestTimeZones(); TestTimeRange(); - TestTimeJulian(); + TestTimeJDN(); #endif // TEST_TIME wxUninitialize(); diff --git a/src/common/datetime.cpp b/src/common/datetime.cpp index 09215a7592..e623c60294 100644 --- a/src/common/datetime.cpp +++ b/src/common/datetime.cpp @@ -1,13 +1,39 @@ -///////////////////////////////////////////////////////////////////////////// +/////////////////////////////////////////////////////////////////////////////// // 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) + * + * 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) + * + */ // ============================================================================ // declarations @@ -57,6 +83,18 @@ static const long MILLISECONDS_PER_DAY = 86400000l; // (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 // ---------------------------------------------------------------------------- @@ -96,7 +134,7 @@ static int GetTimeZone() if ( !s_timezoneSet ) { - // just call localtime() instead of figurin out whether this system + // just call localtime() instead of figuring out whether this system // supports tzset(), _tzset() or something else time_t t; (void)localtime(&t); @@ -108,43 +146,43 @@ static int GetTimeZone() } // 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) +// 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: the algorithm was taken from Peter Baum's home page - - // the algorithm assumes Jan == 1 - int month = mon + 1; - - // we want the leap day (Feb 29) be at the end of the year, so we count - // March as the first month - if ( month < wxDateTime::Mar + 1 ) + // 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 += MONTHS_IN_YEAR; - year--; + month = mon - 2; } - - // this table contains the number of the days before the 1st of the each - // month (in a non leap year) with the third value corresponding to March - // (and the last one to February) - static const int monthOffsets[14] = + else { - 0, 31, 61, 92, 122, 153, 184, 214, 245, 275, 306 - }; + month = mon + 10; + year--; + } - // and now add contributions of all terms together to get the result (you'd - // better see the Web page for the description if you want to understand - // why it works (if it does :-)) - return day + - // linear approximation for months - monthOffsets[month - (wxDateTime::Mar + 1)] + - // the year contribution - 365*year + year/4 - year/100 + year/400 + - // 1721119.5 is the JDN of the midnight of Mar 1, year 0 - 1721118; + // 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) @@ -485,7 +523,7 @@ 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); @@ -500,7 +538,25 @@ wxDateTime& wxDateTime::Set(const struct tm& tm1) wxASSERT_MSG( IsValid(), _T("invalid wxDateTime") ); tm tm2(tm1); + + // we want the time in GMT, mktime() takes the local time, so use timegm() + // if it's available +#ifdef HAVE_TIMEGM + time_t timet = timegm(&tm2); +#else // !HAVE_TIMEGM + // FIXME this almost surely doesn't work + tm2.tm_sec -= GetTimeZone(); + time_t timet = mktime(&tm2); + + if ( tm2.tm_isdst ) + { + tm2.tm_hour += 1; + + timet = mktime(&tm2); + } +#endif // HAVE_TIMEGM/!HAVE_TIMEGM + if ( timet == (time_t)(-1) ) { wxFAIL_MSG(_T("Invalid time")); @@ -528,7 +584,7 @@ wxDateTime& wxDateTime::Set(wxDateTime_t hour, // get the current date from system time_t timet = GetTimeNow(); - struct tm *tm = localtime(&timet); + struct tm *tm = gmtime(&timet); // adjust the time tm->tm_hour = hour; @@ -557,7 +613,8 @@ 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) @@ -577,6 +634,7 @@ 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 (wrongly, probably) (void)Set(tm); @@ -601,7 +659,12 @@ wxDateTime& wxDateTime::Set(wxDateTime_t day, wxDateTime& wxDateTime::Set(double jdn) { - m_time = (jdn - 0.5 - EPOCH_JDN) * TIME_T_FACTOR; + // 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; } @@ -618,45 +681,77 @@ wxDateTime::Tm wxDateTime::GetTm() const if ( time != (time_t)-1 ) { // use C RTL functions - tm *tm = localtime(&time); + tm *tm = gmtime(&time); // should never happen - wxCHECK_MSG( tm, Tm(), _T("localtime() failed") ); + wxCHECK_MSG( tm, Tm(), _T("gmtime() failed") ); return Tm(*tm); } else { - // CREDIT: the algorithm was taken from Peter Baum's home page + // remember the time and do the calculations with the date only - this + // eliminates rounding errors of the floating point arithmetics - // calculate the Gregorian date from JDN for the midnight of our date wxLongLong timeMidnight = m_time; - long timeOnly = (m_time % MILLISECONDS_PER_DAY).GetLo(); + + long timeOnly = (m_time % MILLISECONDS_PER_DAY).ToLong(); + if ( timeOnly < 0 ) + { + timeOnly = MILLISECONDS_PER_DAY - timeOnly; + } + timeMidnight -= timeOnly; - // TODO this probably could be optimised somehow... - - double jdn = (timeMidnight / MILLISECONDS_PER_DAY).GetLo(); - jdn += EPOCH_JDN + 0.5; - long z = jdn - 1721118.5; - double r = jdn - 1721118.5 - z; - double g = z - 0.25; - long a = g/36524.25; // number of days per year - long b = a - a / 4; - int year = (b + g) / 365.25; - long c = b + z - 365.25*year; - int month = (5*c + 456)/153; - int day = c - (153*month - 457)/5 + (r < 0.5 ? 0 : 1); - if ( month > 12 ) + // 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 ) { - year++; - month -= 12; + 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 = year; + tm.year = (int)year; tm.mon = (Month)(month - 1); // algorithm yields 1 for January, not 0 - tm.mday = day; + tm.mday = (wxDateTime_t)day; tm.msec = timeOnly % 1000; timeOnly -= tm.msec; timeOnly /= 1000; // now we have time in seconds @@ -905,10 +1000,10 @@ wxString wxDateTime::Format(const wxChar *format) const if ( time != (time_t)-1 ) { // use strftime() - tm *tm = localtime(&time); + tm *tm = gmtime(&time); // should never happen - wxCHECK_MSG( tm, _T(""), _T("localtime() failed") ); + wxCHECK_MSG( tm, _T(""), _T("gmtime() failed") ); return CallStrftime(format, tm); } -- 2.45.2