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// ==++==
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// ==--==
namespace System.Globalization {
using System;
using System.Runtime.Serialization;
using System.Threading;
using System.Diagnostics.Contracts;
// Gregorian Calendars use Era Info
// Note: We shouldn't have to serialize this since the info doesn't change, but we have been.
// (We really only need the calendar #, and maybe culture)
[Serializable]
internal class EraInfo
{
internal int era; // The value of the era.
internal long ticks; // The time in ticks when the era starts
internal int yearOffset; // The offset to Gregorian year when the era starts.
// Gregorian Year = Era Year + yearOffset
// Era Year = Gregorian Year - yearOffset
internal int minEraYear; // Min year value in this era. Generally, this value is 1, but this may
// be affected by the DateTime.MinValue;
internal int maxEraYear; // Max year value in this era. (== the year length of the era + 1)
[OptionalField(VersionAdded = 4)]
internal String eraName; // The era name
[OptionalField(VersionAdded = 4)]
internal String abbrevEraName; // Abbreviated Era Name
[OptionalField(VersionAdded = 4)]
internal String englishEraName; // English era name
internal EraInfo(int era, int startYear, int startMonth, int startDay, int yearOffset, int minEraYear, int maxEraYear)
{
this.era = era;
this.yearOffset = yearOffset;
this.minEraYear = minEraYear;
this.maxEraYear = maxEraYear;
this.ticks = new DateTime(startYear, startMonth, startDay).Ticks;
}
internal EraInfo(int era, int startYear, int startMonth, int startDay, int yearOffset, int minEraYear, int maxEraYear,
String eraName, String abbrevEraName, String englishEraName)
{
this.era = era;
this.yearOffset = yearOffset;
this.minEraYear = minEraYear;
this.maxEraYear = maxEraYear;
this.ticks = new DateTime(startYear, startMonth, startDay).Ticks;
this.eraName = eraName;
this.abbrevEraName = abbrevEraName;
this.englishEraName = englishEraName;
}
}
// This calendar recognizes two era values:
// 0 CurrentEra (AD)
// 1 BeforeCurrentEra (BC)
[Serializable] internal class GregorianCalendarHelper {
// 1 tick = 100ns = 10E-7 second
// Number of ticks per time unit
internal const long TicksPerMillisecond = 10000;
internal const long TicksPerSecond = TicksPerMillisecond * 1000;
internal const long TicksPerMinute = TicksPerSecond * 60;
internal const long TicksPerHour = TicksPerMinute * 60;
internal const long TicksPerDay = TicksPerHour * 24;
// Number of milliseconds per time unit
internal const int MillisPerSecond = 1000;
internal const int MillisPerMinute = MillisPerSecond * 60;
internal const int MillisPerHour = MillisPerMinute * 60;
internal const int MillisPerDay = MillisPerHour * 24;
// Number of days in a non-leap year
internal const int DaysPerYear = 365;
// Number of days in 4 years
internal const int DaysPer4Years = DaysPerYear * 4 + 1;
// Number of days in 100 years
internal const int DaysPer100Years = DaysPer4Years * 25 - 1;
// Number of days in 400 years
internal const int DaysPer400Years = DaysPer100Years * 4 + 1;
// Number of days from 1/1/0001 to 1/1/10000
internal const int DaysTo10000 = DaysPer400Years * 25 - 366;
internal const long MaxMillis = (long)DaysTo10000 * MillisPerDay;
internal const int DatePartYear = 0;
internal const int DatePartDayOfYear = 1;
internal const int DatePartMonth = 2;
internal const int DatePartDay = 3;
//
// This is the max Gregorian year can be represented by DateTime class. The limitation
// is derived from DateTime class.
//
internal int MaxYear {
get {
return (m_maxYear);
}
}
internal static readonly int[] DaysToMonth365 =
{
0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365
};
internal static readonly int[] DaysToMonth366 =
{
0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366
};
// Strictly these don't need serialized since they can be recreated from the calendar id
[OptionalField(VersionAdded = 1)]
internal int m_maxYear = 9999;
[OptionalField(VersionAdded = 1)]
internal int m_minYear;
internal Calendar m_Cal;
// Era information doesn't need serialized, its constant for the same calendars (ie: we can recreate it from the calendar id)
[OptionalField(VersionAdded = 1)]
internal EraInfo[] m_EraInfo;
[OptionalField(VersionAdded = 1)]
internal int[] m_eras = null;
// m_minDate is existing here just to keep the serialization compatibility.
// it has nothing to do with the code anymore.
[OptionalField(VersionAdded = 1)]
internal DateTime m_minDate;
// Construct an instance of gregorian calendar.
internal GregorianCalendarHelper(Calendar cal, EraInfo[] eraInfo) {
m_Cal = cal;
m_EraInfo = eraInfo;
// m_minDate is existing here just to keep the serialization compatibility.
// it has nothing to do with the code anymore.
m_minDate = m_Cal.MinSupportedDateTime;
m_maxYear = m_EraInfo[0].maxEraYear;
m_minYear = m_EraInfo[0].minEraYear;;
}
// EraInfo.yearOffset: The offset to Gregorian year when the era starts. Gregorian Year = Era Year + yearOffset
// Era Year = Gregorian Year - yearOffset
// EraInfo.minEraYear: Min year value in this era. Generally, this value is 1, but this may be affected by the DateTime.MinValue;
// EraInfo.maxEraYear: Max year value in this era. (== the year length of the era + 1)
// Returns the year offset that convert the year to Gregorian (i.e. Gregorian Year = Era Year + yearOffset)
// Returns negative number if failed.
private int GetYearOffset(int year, int era, bool throwOnError)
{
if (year < 0)
{
if (throwOnError)
{
throw new ArgumentOutOfRangeException("year", Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
}
return -1;
}
if (era == Calendar.CurrentEra)
{
era = m_Cal.CurrentEraValue;
}
for (int i = 0; i < m_EraInfo.Length; i++)
{
if (era == m_EraInfo[i].era)
{
if (year >= m_EraInfo[i].minEraYear)
{
if (year <= m_EraInfo[i].maxEraYear)
{
return m_EraInfo[i].yearOffset;
}
else if (!AppContextSwitches.EnforceJapaneseEraYearRanges)
{
// If we got the year number exceeding the era max year number, this still possible be valid as the date can be created before
// introducing new eras after the era we are checking. we'll loop on the eras after the era we have and ensure the year
// can exist in one of these eras. otherwise, we'll throw.
// Note, we always return the offset associated with the requested era.
//
// Here is some example:
// if we are getting the era number 4 (Heisei) and getting the year number 32. if the era 4 has year range from 1 to 31
// then year 32 exceeded the range of era 4 and we'll try to find out if the years difference (32 - 31 = 1) would lay in
// the subsequent eras (e.g era 5 and up)
int remainingYears = year - m_EraInfo[i].maxEraYear;
for (int j = i - 1; j >= 0; j--)
{
if (remainingYears <= m_EraInfo[j].maxEraYear)
{
return m_EraInfo[i].yearOffset;
}
remainingYears -= m_EraInfo[j].maxEraYear;
}
}
}
if (throwOnError)
{
throw new ArgumentOutOfRangeException("year", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"),
m_EraInfo[i].minEraYear, m_EraInfo[i].maxEraYear));
}
break; // no need to iterate more on eras.
}
}
if (throwOnError)
{
throw new ArgumentOutOfRangeException("era", Environment.GetResourceString("ArgumentOutOfRange_InvalidEraValue"));
}
return -1;
}
/*=================================GetGregorianYear==========================
**Action: Get the Gregorian year value for the specified year in an era.
**Returns: The Gregorian year value.
**Arguments:
** year the year value in Japanese calendar
** era the Japanese emperor era value.
**Exceptions:
** ArgumentOutOfRangeException if year value is invalid or era value is invalid.
============================================================================*/
internal int GetGregorianYear(int year, int era)
{
Contract.EndContractBlock();
return GetYearOffset(year, era, throwOnError: true) + year;
}
internal bool IsValidYear(int year, int era)
{
return GetYearOffset(year, era, throwOnError: false) >= 0;
}
// Returns a given date part of this DateTime. This method is used
// to compute the year, day-of-year, month, or day part.
internal virtual int GetDatePart(long ticks, int part)
{
CheckTicksRange(ticks);
// n = number of days since 1/1/0001
int n = (int)(ticks / TicksPerDay);
// y400 = number of whole 400-year periods since 1/1/0001
int y400 = n / DaysPer400Years;
// n = day number within 400-year period
n -= y400 * DaysPer400Years;
// y100 = number of whole 100-year periods within 400-year period
int y100 = n / DaysPer100Years;
// Last 100-year period has an extra day, so decrement result if 4
if (y100 == 4) y100 = 3;
// n = day number within 100-year period
n -= y100 * DaysPer100Years;
// y4 = number of whole 4-year periods within 100-year period
int y4 = n / DaysPer4Years;
// n = day number within 4-year period
n -= y4 * DaysPer4Years;
// y1 = number of whole years within 4-year period
int y1 = n / DaysPerYear;
// Last year has an extra day, so decrement result if 4
if (y1 == 4) y1 = 3;
// If year was requested, compute and return it
if (part == DatePartYear)
{
return (y400 * 400 + y100 * 100 + y4 * 4 + y1 + 1);
}
// n = day number within year
n -= y1 * DaysPerYear;
// If day-of-year was requested, return it
if (part == DatePartDayOfYear)
{
return (n + 1);
}
// Leap year calculation looks different from IsLeapYear since y1, y4,
// and y100 are relative to year 1, not year 0
bool leapYear = (y1 == 3 && (y4 != 24 || y100 == 3));
int[] days = leapYear? DaysToMonth366: DaysToMonth365;
// All months have less than 32 days, so n >> 5 is a good conservative
// estimate for the month
int m = n >> 5 + 1;
// m = 1-based month number
while (n >= days[m]) m++;
// If month was requested, return it
if (part == DatePartMonth) return (m);
// Return 1-based day-of-month
return (n - days[m - 1] + 1);
}
/*=================================GetAbsoluteDate==========================
**Action: Gets the absolute date for the given Gregorian date. The absolute date means
** the number of days from January 1st, 1 A.D.
**Returns: the absolute date
**Arguments:
** year the Gregorian year
** month the Gregorian month
** day the day
**Exceptions:
** ArgumentOutOfRangException if year, month, day value is valid.
**Note:
** This is an internal method used by DateToTicks() and the calculations of Hijri and Hebrew calendars.
** Number of Days in Prior Years (both common and leap years) +
** Number of Days in Prior Months of Current Year +
** Number of Days in Current Month
**
============================================================================*/
internal static long GetAbsoluteDate(int year, int month, int day) {
if (year >= 1 && year <= 9999 && month >= 1 && month <= 12)
{
int[] days = ((year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))) ? DaysToMonth366: DaysToMonth365;
if (day >= 1 && (day <= days[month] - days[month - 1])) {
int y = year - 1;
int absoluteDate = y * 365 + y / 4 - y / 100 + y / 400 + days[month - 1] + day - 1;
return (absoluteDate);
}
}
throw new ArgumentOutOfRangeException(null, Environment.GetResourceString("ArgumentOutOfRange_BadYearMonthDay"));
}
// Returns the tick count corresponding to the given year, month, and day.
// Will check the if the parameters are valid.
internal static long DateToTicks(int year, int month, int day) {
return (GetAbsoluteDate(year, month, day)* TicksPerDay);
}
// Return the tick count corresponding to the given hour, minute, second.
// Will check the if the parameters are valid.
internal static long TimeToTicks(int hour, int minute, int second, int millisecond)
{
//TimeSpan.TimeToTicks is a family access function which does no error checking, so
//we need to put some error checking out here.
if (hour >= 0 && hour < 24 && minute >= 0 && minute < 60 && second >=0 && second < 60)
{
if (millisecond < 0 || millisecond >= MillisPerSecond) {
throw new ArgumentOutOfRangeException(
"millisecond",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"),
0,
MillisPerSecond - 1));
}
return (TimeSpan.TimeToTicks(hour, minute, second) + millisecond * TicksPerMillisecond);;
}
throw new ArgumentOutOfRangeException(null, Environment.GetResourceString("ArgumentOutOfRange_BadHourMinuteSecond"));
}
internal void CheckTicksRange(long ticks) {
if (ticks < m_Cal.MinSupportedDateTime.Ticks || ticks > m_Cal.MaxSupportedDateTime.Ticks) {
throw new ArgumentOutOfRangeException(
"time",
String.Format(
CultureInfo.InvariantCulture,
Environment.GetResourceString("ArgumentOutOfRange_CalendarRange"),
m_Cal.MinSupportedDateTime,
m_Cal.MaxSupportedDateTime));
}
Contract.EndContractBlock();
}
// Returns the DateTime resulting from adding the given number of
// months to the specified DateTime. The result is computed by incrementing
// (or decrementing) the year and month parts of the specified DateTime by
// value months, and, if required, adjusting the day part of the
// resulting date downwards to the last day of the resulting month in the
// resulting year. The time-of-day part of the result is the same as the
// time-of-day part of the specified DateTime.
//
// In more precise terms, considering the specified DateTime to be of the
// form y / m / d + t, where y is the
// year, m is the month, d is the day, and t is the
// time-of-day, the result is y1 / m1 / d1 + t,
// where y1 and m1 are computed by adding value months
// to y and m, and d1 is the largest value less than
// or equal to d that denotes a valid day in month m1 of year
// y1.
//
public DateTime AddMonths(DateTime time, int months)
{
if (months < -120000 || months > 120000) {
throw new ArgumentOutOfRangeException(
"months",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"),
-120000,
120000));
}
Contract.EndContractBlock();
CheckTicksRange(time.Ticks);
int y = GetDatePart(time.Ticks, DatePartYear);
int m = GetDatePart(time.Ticks, DatePartMonth);
int d = GetDatePart(time.Ticks, DatePartDay);
int i = m - 1 + months;
if (i >= 0)
{
m = i % 12 + 1;
y = y + i / 12;
}
else
{
m = 12 + (i + 1) % 12;
y = y + (i - 11) / 12;
}
int[] daysArray = (y % 4 == 0 && (y % 100 != 0 || y % 400 == 0)) ? DaysToMonth366: DaysToMonth365;
int days = (daysArray[m] - daysArray[m - 1]);
if (d > days)
{
d = days;
}
long ticks = DateToTicks(y, m, d) + (time.Ticks % TicksPerDay);
Calendar.CheckAddResult(ticks, m_Cal.MinSupportedDateTime, m_Cal.MaxSupportedDateTime);
return (new DateTime(ticks));
}
// Returns the DateTime resulting from adding the given number of
// years to the specified DateTime. The result is computed by incrementing
// (or decrementing) the year part of the specified DateTime by value
// years. If the month and day of the specified DateTime is 2/29, and if the
// resulting year is not a leap year, the month and day of the resulting
// DateTime becomes 2/28. Otherwise, the month, day, and time-of-day
// parts of the result are the same as those of the specified DateTime.
//
public DateTime AddYears(DateTime time, int years)
{
return (AddMonths(time, years * 12));
}
// Returns the day-of-month part of the specified DateTime. The returned
// value is an integer between 1 and 31.
//
public int GetDayOfMonth(DateTime time)
{
return (GetDatePart(time.Ticks, DatePartDay));
}
// Returns the day-of-week part of the specified DateTime. The returned value
// is an integer between 0 and 6, where 0 indicates Sunday, 1 indicates
// Monday, 2 indicates Tuesday, 3 indicates Wednesday, 4 indicates
// Thursday, 5 indicates Friday, and 6 indicates Saturday.
//
public DayOfWeek GetDayOfWeek(DateTime time)
{
CheckTicksRange(time.Ticks);
return ((DayOfWeek)((time.Ticks / TicksPerDay + 1) % 7));
}
// Returns the day-of-year part of the specified DateTime. The returned value
// is an integer between 1 and 366.
//
public int GetDayOfYear(DateTime time)
{
return (GetDatePart(time.Ticks, DatePartDayOfYear));
}
// Returns the number of days in the month given by the year and
// month arguments.
//
[Pure]
public int GetDaysInMonth(int year, int month, int era) {
//
// Convert year/era value to Gregorain year value.
//
year = GetGregorianYear(year, era);
if (month < 1 || month > 12) {
throw new ArgumentOutOfRangeException("month", Environment.GetResourceString("ArgumentOutOfRange_Month"));
}
int[] days = ((year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)) ? DaysToMonth366: DaysToMonth365);
return (days[month] - days[month - 1]);
}
// Returns the number of days in the year given by the year argument for the current era.
//
public int GetDaysInYear(int year, int era)
{
//
// Convert year/era value to Gregorain year value.
//
year = GetGregorianYear(year, era);
return ((year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)) ? 366:365);
}
// Returns the era for the specified DateTime value.
public int GetEra(DateTime time)
{
long ticks = time.Ticks;
// The assumption here is that m_EraInfo is listed in reverse order.
for (int i = 0; i < m_EraInfo.Length; i++) {
if (ticks >= m_EraInfo[i].ticks) {
return (m_EraInfo[i].era);
}
}
throw new ArgumentOutOfRangeException(Environment.GetResourceString("ArgumentOutOfRange_Era"));
}
public int[] Eras {
get {
if (m_eras == null) {
m_eras = new int[m_EraInfo.Length];
for (int i = 0; i < m_EraInfo.Length; i++) {
m_eras[i] = m_EraInfo[i].era;
}
}
return ((int[])m_eras.Clone());
}
}
// Returns the month part of the specified DateTime. The returned value is an
// integer between 1 and 12.
//
public int GetMonth(DateTime time)
{
return (GetDatePart(time.Ticks, DatePartMonth));
}
// Returns the number of months in the specified year and era.
public int GetMonthsInYear(int year, int era)
{
year = GetGregorianYear(year, era);
return (12);
}
// Returns the year part of the specified DateTime. The returned value is an
// integer between 1 and 9999.
//
public int GetYear(DateTime time)
{
long ticks = time.Ticks;
int year = GetDatePart(ticks, DatePartYear);
for (int i = 0; i < m_EraInfo.Length; i++) {
if (ticks >= m_EraInfo[i].ticks) {
return (year - m_EraInfo[i].yearOffset);
}
}
throw new ArgumentException(Environment.GetResourceString("Argument_NoEra"));
}
// Returns the year that match the specified Gregorian year. The returned value is an
// integer between 1 and 9999.
//
public int GetYear(int year, DateTime time)
{
long ticks = time.Ticks;
for (int i = 0; i < m_EraInfo.Length; i++) {
if (ticks >= m_EraInfo[i].ticks) {
return (year - m_EraInfo[i].yearOffset);
}
}
throw new ArgumentException(Environment.GetResourceString("Argument_NoEra"));
}
// Checks whether a given day in the specified era is a leap day. This method returns true if
// the date is a leap day, or false if not.
//
public bool IsLeapDay(int year, int month, int day, int era)
{
// year/month/era checking is done in GetDaysInMonth()
if (day < 1 || day > GetDaysInMonth(year, month, era)) {
throw new ArgumentOutOfRangeException(
"day",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"),
1,
GetDaysInMonth(year, month, era)));
}
Contract.EndContractBlock();
if (!IsLeapYear(year, era)) {
return (false);
}
if (month == 2 && day == 29) {
return (true);
}
return (false);
}
// Returns the leap month in a calendar year of the specified era. This method returns 0
// if this calendar does not have leap month, or this year is not a leap year.
//
public int GetLeapMonth(int year, int era)
{
year = GetGregorianYear(year, era);
return (0);
}
// Checks whether a given month in the specified era is a leap month. This method returns true if
// month is a leap month, or false if not.
//
public bool IsLeapMonth(int year, int month, int era)
{
year = GetGregorianYear(year, era);
if (month < 1 || month > 12) {
throw new ArgumentOutOfRangeException(
"month",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"),
1,
12));
}
return (false);
}
// Checks whether a given year in the specified era is a leap year. This method returns true if
// year is a leap year, or false if not.
//
public bool IsLeapYear(int year, int era) {
year = GetGregorianYear(year, era);
return (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
}
// Returns the date and time converted to a DateTime value. Throws an exception if the n-tuple is invalid.
//
public DateTime ToDateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int era) {
year = GetGregorianYear(year, era);
long ticks = DateToTicks(year, month, day) + TimeToTicks(hour, minute, second, millisecond);
CheckTicksRange(ticks);
return (new DateTime(ticks));
}
public virtual int GetWeekOfYear(DateTime time, CalendarWeekRule rule, DayOfWeek firstDayOfWeek) {
CheckTicksRange(time.Ticks);
// Use GregorianCalendar to get around the problem that the implmentation in Calendar.GetWeekOfYear()
// can call GetYear() that exceeds the supported range of the Gregorian-based calendars.
return (GregorianCalendar.GetDefaultInstance().GetWeekOfYear(time, rule, firstDayOfWeek));
}
public int ToFourDigitYear(int year, int twoDigitYearMax) {
if (year < 0) {
throw new ArgumentOutOfRangeException("year",
Environment.GetResourceString("ArgumentOutOfRange_NeedPosNum"));
}
Contract.EndContractBlock();
if (year < 100) {
int y = year % 100;
return ((twoDigitYearMax/100 - ( y > twoDigitYearMax % 100 ? 1 : 0))*100 + y);
}
if (year < m_minYear || year > m_maxYear) {
throw new ArgumentOutOfRangeException(
"year",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"), m_minYear, m_maxYear));
}
// If the year value is above 100, just return the year value. Don't have to do
// the TwoDigitYearMax comparison.
return (year);
}
}
}
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