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| -rw-r--r-- | tools/source/datetime/tdate.cxx | 586 |
1 files changed, 586 insertions, 0 deletions
diff --git a/tools/source/datetime/tdate.cxx b/tools/source/datetime/tdate.cxx new file mode 100644 index 000000000..e3fd7eff5 --- /dev/null +++ b/tools/source/datetime/tdate.cxx @@ -0,0 +1,586 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ +#include <tools/date.hxx> +#include <sal/log.hxx> +#include <com/sun/star/util/DateTime.hpp> + +#include <systemdatetime.hxx> + +static const sal_uInt16 aDaysInMonth[12] = { 31, 28, 31, 30, 31, 30, + 31, 31, 30, 31, 30, 31 }; + +// Once upon a time the number of days we internally handled was limited to +// MAX_DAYS 3636532. That changed with a full 16-bit year. +// Assuming the first valid positive date in a proleptic Gregorian calendar is +// 0001-01-01, this resulted in an end date of 9957-06-26. +// Hence we documented that years up to and including 9956 are handled. +/* XXX: it is unclear history why this value was chosen, the representable + * 9999-12-31 would be 3652060 days from 0001-01-01. Even 9998-12-31 to + * distinguish from a maximum possible date would be 3651695. + * There is connectivity/source/commontools/dbconversion.cxx that still has the + * same value to calculate with css::util::Date */ +/* XXX can that dbconversion cope with years > 9999 or negative years at all? + * Database fields may be limited to positive 4 digits. */ + +static const sal_Int32 MIN_DAYS = -11968265; // -32768-01-01 +static const sal_Int32 MAX_DAYS = 11967900; // 32767-12-31 + +namespace +{ + +const sal_Int16 kYearMax = SAL_MAX_INT16; +const sal_Int16 kYearMin = SAL_MIN_INT16; + +// Days until start of year from zero, so month and day of month can be added. +// year 1 => 0 days, year 2 => 365 days, ... +// year -1 => -366 days, year -2 => -731 days, ... +sal_Int32 ImpYearToDays( sal_Int16 nYear ) +{ + assert( nYear != 0 ); + sal_Int32 nOffset; + sal_Int32 nYr; + if (nYear < 0) + { + nOffset = -366; + nYr = nYear + 1; + } + else + { + nOffset = 0; + nYr = nYear - 1; + } + return nOffset + nYr*365 + nYr/4 - nYr/100 + nYr/400; +} + +bool ImpIsLeapYear( sal_Int16 nYear ) +{ + // Leap years BCE are -1, -5, -9, ... + // See + // https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar#Usage + // https://en.wikipedia.org/wiki/0_(year)#History_of_astronomical_usage + assert( nYear != 0 ); + if (nYear < 0) + nYear = -nYear - 1; + return ( ( ((nYear % 4) == 0) && ((nYear % 100) != 0) ) || + ( (nYear % 400) == 0 ) ); +} + +// All callers must have sanitized or normalized month and year values! +sal_uInt16 ImplDaysInMonth( sal_uInt16 nMonth, sal_Int16 nYear ) +{ + if ( nMonth != 2 ) + return aDaysInMonth[nMonth-1]; + else + { + if (ImpIsLeapYear(nYear)) + return aDaysInMonth[nMonth-1] + 1; + else + return aDaysInMonth[nMonth-1]; + } +} + +} + +void Date::setDateFromDMY( sal_uInt16 nDay, sal_uInt16 nMonth, sal_Int16 nYear ) +{ + // don't warn about 0/0/0, commonly used as a default-value/no-value + SAL_WARN_IF( nYear == 0 && !(nYear == 0 && nMonth == 0 && nDay == 0), + "tools.datetime", "Date::setDateFromDMY - sure about 0 year? It's not in the calendar."); + assert( nMonth < 100 && "nMonth % 100 not representable" ); + assert( nDay < 100 && "nDay % 100 not representable" ); + if (nYear < 0) + mnDate = + (static_cast<sal_Int32>( nYear ) * 10000) - + (static_cast<sal_Int32>( nMonth % 100 ) * 100) - + static_cast<sal_Int32>( nDay % 100 ); + else + mnDate = + (static_cast<sal_Int32>( nYear ) * 10000) + + (static_cast<sal_Int32>( nMonth % 100 ) * 100) + + static_cast<sal_Int32>( nDay % 100 ); +} + +void Date::SetDate( sal_Int32 nNewDate ) +{ + assert( ((nNewDate / 10000) != 0) && "you don't want to set a 0 year, do you?" ); + mnDate = nNewDate; +} + +// static +sal_uInt16 Date::GetDaysInMonth( sal_uInt16 nMonth, sal_Int16 nYear ) +{ + SAL_WARN_IF( nMonth < 1 || 12 < nMonth, "tools.datetime", "Date::GetDaysInMonth - nMonth out of bounds " << nMonth); + if (nMonth < 1) + nMonth = 1; + else if (12 < nMonth) + nMonth = 12; + return ImplDaysInMonth( nMonth, nYear); +} + +sal_Int32 Date::GetAsNormalizedDays() const +{ + // This is a very common datum we often calculate from. + if (mnDate == 18991230) // 1899-12-30 + { + assert(DateToDays( GetDay(), GetMonth(), GetYear() ) == 693594); + return 693594; + } + return DateToDays( GetDay(), GetMonth(), GetYear() ); +} + +sal_Int32 Date::DateToDays( sal_uInt16 nDay, sal_uInt16 nMonth, sal_Int16 nYear ) +{ + Normalize( nDay, nMonth, nYear); + + sal_Int32 nDays = ImpYearToDays(nYear); + for( sal_uInt16 i = 1; i < nMonth; i++ ) + nDays += ImplDaysInMonth(i,nYear); + nDays += nDay; + return nDays; +} + +static Date lcl_DaysToDate( sal_Int32 nDays ) +{ + if ( nDays <= MIN_DAYS ) + return Date( 1, 1, kYearMin ); + if ( nDays >= MAX_DAYS ) + return Date( 31, 12, kYearMax ); + + // Day 0 is -0001-12-31, day 1 is 0001-01-01 + const sal_Int16 nSign = (nDays <= 0 ? -1 : 1); + sal_Int32 nTempDays; + sal_Int32 i = 0; + bool bCalc; + + sal_Int16 nYear; + do + { + nYear = static_cast<sal_Int16>((nDays / 365) - (i * nSign)); + if (nYear == 0) + nYear = nSign; + nTempDays = nDays - ImpYearToDays(nYear); + bCalc = false; + if ( nTempDays < 1 ) + { + i += nSign; + bCalc = true; + } + else + { + if ( nTempDays > 365 ) + { + if ( (nTempDays != 366) || !ImpIsLeapYear( nYear ) ) + { + i -= nSign; + bCalc = true; + } + } + } + } + while ( bCalc ); + + sal_uInt16 nMonth = 1; + while ( nTempDays > ImplDaysInMonth( nMonth, nYear ) ) + { + nTempDays -= ImplDaysInMonth( nMonth, nYear ); + ++nMonth; + } + + return Date( static_cast<sal_uInt16>(nTempDays), nMonth, nYear ); +} + +Date::Date( DateInitSystem ) +{ + if ( !GetSystemDateTime( &mnDate, nullptr ) ) + setDateFromDMY( 1, 1, 1900 ); +} + +Date::Date( const css::util::DateTime& rDateTime ) +{ + setDateFromDMY( rDateTime.Day, rDateTime.Month, rDateTime.Year ); +} + +void Date::SetDay( sal_uInt16 nNewDay ) +{ + setDateFromDMY( nNewDay, GetMonth(), GetYear() ); +} + +void Date::SetMonth( sal_uInt16 nNewMonth ) +{ + setDateFromDMY( GetDay(), nNewMonth, GetYear() ); +} + +void Date::SetYear( sal_Int16 nNewYear ) +{ + assert( nNewYear != 0 ); + setDateFromDMY( GetDay(), GetMonth(), nNewYear ); +} + +void Date::AddYears( sal_Int16 nAddYears ) +{ + sal_Int16 nYear = GetYear(); + if (nYear < 0) + { + if (nAddYears < 0) + { + if (nYear < kYearMin - nAddYears) + nYear = kYearMin; + else + nYear += nAddYears; + } + else + { + nYear += nAddYears; + if (nYear == 0) + nYear = 1; + } + } + else + { + if (nAddYears > 0) + { + if (kYearMax - nAddYears < nYear) + nYear = kYearMax; + else + nYear += nAddYears; + } + else + { + nYear += nAddYears; + if (nYear == 0) + nYear = -1; + } + } + + SetYear( nYear ); + if (GetMonth() == 2 && GetDay() == 29 && !ImpIsLeapYear( nYear)) + SetDay(28); +} + +void Date::AddMonths( sal_Int32 nAddMonths ) +{ + sal_Int32 nMonths = GetMonth() + nAddMonths; + sal_Int32 nNewMonth = nMonths % 12; + sal_Int32 nYear = GetYear() + nMonths / 12; + if( nMonths <= 0 || nNewMonth == 0 ) + --nYear; + if( nNewMonth <= 0 ) + nNewMonth += 12; + if (nYear == 0) + nYear = (nAddMonths < 0 ? -1 : 1); + else if (nYear < kYearMin) + nYear = kYearMin; + else if (nYear > kYearMax) + nYear = kYearMax; + SetMonth( static_cast<sal_uInt16>(nNewMonth) ); + SetYear( static_cast<sal_Int16>(nYear) ); + Normalize(); +} + +DayOfWeek Date::GetDayOfWeek() const +{ + return static_cast<DayOfWeek>((GetAsNormalizedDays()-1) % 7); +} + +sal_uInt16 Date::GetDayOfYear() const +{ + sal_uInt16 nDay = GetDay(); + sal_uInt16 nMonth = GetMonth(); + sal_Int16 nYear = GetYear(); + Normalize( nDay, nMonth, nYear); + + for( sal_uInt16 i = 1; i < nMonth; i++ ) + nDay += ::ImplDaysInMonth( i, nYear ); + return nDay; +} + +sal_uInt16 Date::GetWeekOfYear( DayOfWeek eStartDay, + sal_Int16 nMinimumNumberOfDaysInWeek ) const +{ + short nWeek; + short n1WDay = static_cast<short>(Date( 1, 1, GetYear() ).GetDayOfWeek()); + short nDayOfYear = static_cast<short>(GetDayOfYear()); + + // weekdays start at 0, thus decrement one + nDayOfYear--; + // account for StartDay + n1WDay = (n1WDay+(7-static_cast<short>(eStartDay))) % 7; + + if (nMinimumNumberOfDaysInWeek < 1 || 7 < nMinimumNumberOfDaysInWeek) + { + SAL_WARN( "tools.datetime", "Date::GetWeekOfYear: invalid nMinimumNumberOfDaysInWeek" ); + nMinimumNumberOfDaysInWeek = 4; + } + + if ( nMinimumNumberOfDaysInWeek == 1 ) + { + nWeek = ((n1WDay+nDayOfYear)/7) + 1; + // Set to 53rd week only if we're not in the + // first week of the new year + if ( nWeek == 54 ) + nWeek = 1; + else if ( nWeek == 53 ) + { + short nDaysInYear = static_cast<short>(GetDaysInYear()); + short nDaysNextYear = static_cast<short>(Date( 1, 1, GetNextYear() ).GetDayOfWeek()); + nDaysNextYear = (nDaysNextYear+(7-static_cast<short>(eStartDay))) % 7; + if ( nDayOfYear > (nDaysInYear-nDaysNextYear-1) ) + nWeek = 1; + } + } + else if ( nMinimumNumberOfDaysInWeek == 7 ) + { + nWeek = ((n1WDay+nDayOfYear)/7); + // First week of a year is equal to the last week of the previous year + if ( nWeek == 0 ) + { + Date aLastDatePrevYear( 31, 12, GetPrevYear() ); + nWeek = aLastDatePrevYear.GetWeekOfYear( eStartDay, nMinimumNumberOfDaysInWeek ); + } + } + else // ( nMinimumNumberOfDaysInWeek == something_else, commentary examples for 4 ) + { + // x_monday - thursday + if ( n1WDay < nMinimumNumberOfDaysInWeek ) + nWeek = 1; + // Friday + else if ( n1WDay == nMinimumNumberOfDaysInWeek ) + nWeek = 53; + // Saturday + else if ( n1WDay == nMinimumNumberOfDaysInWeek + 1 ) + { + // Year after leap year + if ( Date( 1, 1, GetPrevYear() ).IsLeapYear() ) + nWeek = 53; + else + nWeek = 52; + } + // Sunday + else + nWeek = 52; + + if ( (nWeek == 1) || (nDayOfYear + n1WDay > 6) ) + { + if ( nWeek == 1 ) + nWeek += (nDayOfYear + n1WDay) / 7; + else + nWeek = (nDayOfYear + n1WDay) / 7; + if ( nWeek == 53 ) + { + // next x_Sunday == first x_Sunday in the new year + // == still the same week! + sal_Int32 nTempDays = GetAsNormalizedDays(); + + nTempDays += 6 - (GetDayOfWeek()+(7-static_cast<short>(eStartDay))) % 7; + nWeek = lcl_DaysToDate( nTempDays ).GetWeekOfYear( eStartDay, nMinimumNumberOfDaysInWeek ); + } + } + } + + return static_cast<sal_uInt16>(nWeek); +} + +sal_uInt16 Date::GetDaysInMonth() const +{ + sal_uInt16 nDay = GetDay(); + sal_uInt16 nMonth = GetMonth(); + sal_Int16 nYear = GetYear(); + Normalize( nDay, nMonth, nYear); + + return ImplDaysInMonth( nMonth, nYear ); +} + +bool Date::IsLeapYear() const +{ + sal_Int16 nYear = GetYear(); + return ImpIsLeapYear( nYear ); +} + +bool Date::IsValidAndGregorian() const +{ + sal_uInt16 nDay = GetDay(); + sal_uInt16 nMonth = GetMonth(); + sal_Int16 nYear = GetYear(); + + if ( !nMonth || (nMonth > 12) ) + return false; + if ( !nDay || (nDay > ImplDaysInMonth( nMonth, nYear )) ) + return false; + else if ( nYear <= 1582 ) + { + if ( nYear < 1582 ) + return false; + else if ( nMonth < 10 ) + return false; + else if ( (nMonth == 10) && (nDay < 15) ) + return false; + } + + return true; +} + +bool Date::IsValidDate() const +{ + return IsValidDate( GetDay(), GetMonth(), GetYear()); +} + +//static +bool Date::IsValidDate( sal_uInt16 nDay, sal_uInt16 nMonth, sal_Int16 nYear ) +{ + if (nYear == 0) + return false; + if ( !nMonth || (nMonth > 12) ) + return false; + if ( !nDay || (nDay > ImplDaysInMonth( nMonth, nYear )) ) + return false; + return true; +} + +void Date::Normalize() +{ + sal_uInt16 nDay = GetDay(); + sal_uInt16 nMonth = GetMonth(); + sal_Int16 nYear = GetYear(); + + if (!Normalize( nDay, nMonth, nYear)) + return; + + setDateFromDMY( nDay, nMonth, nYear ); +} + +//static +bool Date::Normalize( sal_uInt16 & rDay, sal_uInt16 & rMonth, sal_Int16 & rYear ) +{ + if (IsValidDate( rDay, rMonth, rYear)) + return false; + + if (rDay == 0 && rMonth == 0 && rYear == 0) + return false; // empty date + + if (rDay == 0) + { + if (rMonth == 0) + ; // nothing, handled below + else + --rMonth; + // Last day of month is determined at the end. + } + + if (rMonth > 12) + { + rYear += rMonth / 12; + rMonth = rMonth % 12; + if (rYear == 0) + rYear = 1; + } + if (rMonth == 0) + { + --rYear; + if (rYear == 0) + rYear = -1; + rMonth = 12; + } + + if (rYear < 0) + { + sal_uInt16 nDays; + while (rDay > (nDays = ImplDaysInMonth( rMonth, rYear))) + { + rDay -= nDays; + if (rMonth > 1) + --rMonth; + else + { + if (rYear == kYearMin) + { + rDay = 1; + rMonth = 1; + return true; + } + --rYear; + rMonth = 12; + } + } + } + else + { + sal_uInt16 nDays; + while (rDay > (nDays = ImplDaysInMonth( rMonth, rYear))) + { + rDay -= nDays; + if (rMonth < 12) + ++rMonth; + else + { + if (rYear == kYearMax) + { + rDay = 31; + rMonth = 12; + return true; + } + ++rYear; + rMonth = 1; + } + } + } + + if (rDay == 0) + rDay = ImplDaysInMonth( rMonth, rYear); + + return true; +} + +void Date::AddDays( sal_Int32 nDays ) +{ + if (nDays != 0) + *this = lcl_DaysToDate( GetAsNormalizedDays() + nDays ); +} + +Date& Date::operator ++() +{ + *this = lcl_DaysToDate( GetAsNormalizedDays() + 1 ); + return *this; +} + +Date& Date::operator --() +{ + *this = lcl_DaysToDate( GetAsNormalizedDays() - 1 ); + return *this; +} + +Date operator +( const Date& rDate, sal_Int32 nDays ) +{ + Date aDate( rDate ); + aDate.AddDays( nDays ); + return aDate; +} + +Date operator -( const Date& rDate, sal_Int32 nDays ) +{ + Date aDate( rDate ); + aDate.AddDays( -nDays ); + return aDate; +} + +sal_Int32 operator -( const Date& rDate1, const Date& rDate2 ) +{ + return rDate1.GetAsNormalizedDays() - rDate2.GetAsNormalizedDays(); +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |