private CalendarSystem(CalendarOrdinal ordinal, string id, string name, YearMonthDayCalculator yearMonthDayCalculator, EraCalculator eraCalculator)
{
this.Ordinal = ordinal;
this.Id = id;
this.Name = name;
this.YearMonthDayCalculator = yearMonthDayCalculator;
this.MinYear = yearMonthDayCalculator.MinYear;
this.MaxYear = yearMonthDayCalculator.MaxYear;
this.MinDays = yearMonthDayCalculator.GetStartOfYearInDays(MinYear);
this.MaxDays = yearMonthDayCalculator.GetStartOfYearInDays(MaxYear + 1) - 1;
// We trust the construction code not to mutate the array...
this.eraCalculator = eraCalculator;
CalendarByOrdinal[(int)ordinal] = this;
}
private CalendarSystem(CalendarOrdinal ordinal, string id, string name, YearMonthDayCalculator yearMonthDayCalculator, int minDaysInFirstWeek, EraCalculator eraCalculator)
{
this.Ordinal = ordinal;
this.Id = id;
this.Name = name;
this.YearMonthDayCalculator = yearMonthDayCalculator;
this.weekYearCalculator = new WeekYearCalculator(yearMonthDayCalculator, minDaysInFirstWeek);
this.MinYear = yearMonthDayCalculator.MinYear;
this.MaxYear = yearMonthDayCalculator.MaxYear;
this.MinDays = yearMonthDayCalculator.GetStartOfYearInDays(MinYear);
this.MaxDays = yearMonthDayCalculator.GetStartOfYearInDays(MaxYear + 1) - 1;
// We trust the construction code not to mutate the array...
this.eraCalculator = eraCalculator;
CalendarByOrdinal[(int) ordinal] = this;
}
public void GetStartOfYearInDays_InOptimizedRange()
{
IsoCalculator.GetStartOfYearInDays(2000);
}
/// <summary>
/// Returns the days at the start of the given week-year. The week-year may be
/// 1 higher or lower than the max/min calendar year. For non-regular rules (i.e. where some weeks
/// can be short) it returns the day when the week-year *would* have started if it were regular.
/// So this *always* returns a date on firstDayOfWeek.
/// </summary>
private int GetWeekYearDaysSinceEpoch(YearMonthDayCalculator yearMonthDayCalculator, [Trusted] int weekYear)
{
unchecked
{
// Need to be slightly careful here, as the week-year can reasonably be (just) outside the calendar year range.
// However, YearMonthDayCalculator.GetStartOfYearInDays already handles min/max -/+ 1.
int startOfCalendarYear = yearMonthDayCalculator.GetStartOfYearInDays(weekYear);
int startOfYearDayOfWeek = unchecked(startOfCalendarYear >= -3 ? 1 + ((startOfCalendarYear + 3) % 7)
: 7 + ((startOfCalendarYear + 4) % 7));
// How many days have there been from the start of the week containing
// the first day of the year, until the first day of the year? To put it another
// way, how many days in the week *containing* the start of the calendar year were
// in the previous calendar year.
// (For example, if the start of the calendar year is Friday and the first day of the week is Monday,
// this will be 4.)
int daysIntoWeek = ((startOfYearDayOfWeek - (int)firstDayOfWeek) + 7) % 7;
int startOfWeekContainingStartOfCalendarYear = startOfCalendarYear - daysIntoWeek;
bool startOfYearIsInWeek1 = (7 - daysIntoWeek >= minDaysInFirstWeek);
return startOfYearIsInWeek1
? startOfWeekContainingStartOfCalendarYear
: startOfWeekContainingStartOfCalendarYear + 7;
}
}
