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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /intl/icu/source/i18n/gregoimp.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'intl/icu/source/i18n/gregoimp.h')
-rw-r--r-- | intl/icu/source/i18n/gregoimp.h | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/intl/icu/source/i18n/gregoimp.h b/intl/icu/source/i18n/gregoimp.h new file mode 100644 index 0000000000..d65d6a4f88 --- /dev/null +++ b/intl/icu/source/i18n/gregoimp.h @@ -0,0 +1,312 @@ +// © 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* + ********************************************************************** + * Copyright (c) 2003-2008, International Business Machines + * Corporation and others. All Rights Reserved. + ********************************************************************** + * Author: Alan Liu + * Created: September 2 2003 + * Since: ICU 2.8 + ********************************************************************** + */ + +#ifndef GREGOIMP_H +#define GREGOIMP_H +#include "unicode/utypes.h" +#if !UCONFIG_NO_FORMATTING + +#include "unicode/ures.h" +#include "unicode/locid.h" +#include "putilimp.h" + +U_NAMESPACE_BEGIN + +/** + * A utility class providing mathematical functions used by time zone + * and calendar code. Do not instantiate. Formerly just named 'Math'. + * @internal + */ +class ClockMath { + public: + /** + * Divide two integers, returning the floor of the quotient. + * Unlike the built-in division, this is mathematically + * well-behaved. E.g., <code>-1/4</code> => 0 but + * <code>floorDivide(-1,4)</code> => -1. + * @param numerator the numerator + * @param denominator a divisor which must be != 0 + * @return the floor of the quotient + */ + static int32_t floorDivide(int32_t numerator, int32_t denominator); + + /** + * Divide two integers, returning the floor of the quotient. + * Unlike the built-in division, this is mathematically + * well-behaved. E.g., <code>-1/4</code> => 0 but + * <code>floorDivide(-1,4)</code> => -1. + * @param numerator the numerator + * @param denominator a divisor which must be != 0 + * @return the floor of the quotient + */ + static int64_t floorDivide(int64_t numerator, int64_t denominator); + + /** + * Divide two numbers, returning the floor of the quotient. + * Unlike the built-in division, this is mathematically + * well-behaved. E.g., <code>-1/4</code> => 0 but + * <code>floorDivide(-1,4)</code> => -1. + * @param numerator the numerator + * @param denominator a divisor which must be != 0 + * @return the floor of the quotient + */ + static inline double floorDivide(double numerator, double denominator); + + /** + * Divide two numbers, returning the floor of the quotient and + * the modulus remainder. Unlike the built-in division, this is + * mathematically well-behaved. E.g., <code>-1/4</code> => 0 and + * <code>-1%4</code> => -1, but <code>floorDivide(-1,4)</code> => + * -1 with <code>remainder</code> => 3. NOTE: If numerator is + * too large, the returned quotient may overflow. + * @param numerator the numerator + * @param denominator a divisor which must be != 0 + * @param remainder output parameter to receive the + * remainder. Unlike <code>numerator % denominator</code>, this + * will always be non-negative, in the half-open range <code>[0, + * |denominator|)</code>. + * @return the floor of the quotient + */ + static int32_t floorDivide(double numerator, int32_t denominator, + int32_t* remainder); + + /** + * For a positive divisor, return the quotient and remainder + * such that dividend = quotient*divisor + remainder and + * 0 <= remainder < divisor. + * + * Works around edge-case bugs. Handles pathological input + * (dividend >> divisor) reasonably. + * + * Calling with a divisor <= 0 is disallowed. + */ + static double floorDivide(double dividend, double divisor, + double* remainder); +}; + +// Useful millisecond constants +#define kOneDay (1.0 * U_MILLIS_PER_DAY) // 86,400,000 +#define kOneHour (60*60*1000) +#define kOneMinute 60000 +#define kOneSecond 1000 +#define kOneMillisecond 1 +#define kOneWeek (7.0 * kOneDay) // 604,800,000 + +// Epoch constants +#define kJan1_1JulianDay 1721426 // January 1, year 1 (Gregorian) + +#define kEpochStartAsJulianDay 2440588 // January 1, 1970 (Gregorian) + +#define kEpochYear 1970 + + +#define kEarliestViableMillis -185331720384000000.0 // minimum representable by julian day -1e17 + +#define kLatestViableMillis 185753453990400000.0 // max representable by julian day +1e17 + +/** + * The minimum supported Julian day. This value is equivalent to + * MIN_MILLIS. + */ +#define MIN_JULIAN (-0x7F000000) + +/** + * The minimum supported epoch milliseconds. This value is equivalent + * to MIN_JULIAN. + */ +#define MIN_MILLIS ((MIN_JULIAN - kEpochStartAsJulianDay) * kOneDay) + +/** + * The maximum supported Julian day. This value is equivalent to + * MAX_MILLIS. + */ +#define MAX_JULIAN (+0x7F000000) + +/** + * The maximum supported epoch milliseconds. This value is equivalent + * to MAX_JULIAN. + */ +#define MAX_MILLIS ((MAX_JULIAN - kEpochStartAsJulianDay) * kOneDay) + +/** + * A utility class providing proleptic Gregorian calendar functions + * used by time zone and calendar code. Do not instantiate. + * + * Note: Unlike GregorianCalendar, all computations performed by this + * class occur in the pure proleptic GregorianCalendar. + */ +class Grego { + public: + /** + * Return true if the given year is a leap year. + * @param year Gregorian year, with 0 == 1 BCE, -1 == 2 BCE, etc. + * @return true if the year is a leap year + */ + static inline UBool isLeapYear(int32_t year); + + /** + * Return the number of days in the given month. + * @param year Gregorian year, with 0 == 1 BCE, -1 == 2 BCE, etc. + * @param month 0-based month, with 0==Jan + * @return the number of days in the given month + */ + static inline int8_t monthLength(int32_t year, int32_t month); + + /** + * Return the length of a previous month of the Gregorian calendar. + * @param y the extended year + * @param m the 0-based month number + * @return the number of days in the month previous to the given month + */ + static inline int8_t previousMonthLength(int y, int m); + + /** + * Convert a year, month, and day-of-month, given in the proleptic + * Gregorian calendar, to 1970 epoch days. + * @param year Gregorian year, with 0 == 1 BCE, -1 == 2 BCE, etc. + * @param month 0-based month, with 0==Jan + * @param dom 1-based day of month + * @return the day number, with day 0 == Jan 1 1970 + */ + static double fieldsToDay(int32_t year, int32_t month, int32_t dom); + + /** + * Convert a 1970-epoch day number to proleptic Gregorian year, + * month, day-of-month, and day-of-week. + * @param day 1970-epoch day (integral value) + * @param year output parameter to receive year + * @param month output parameter to receive month (0-based, 0==Jan) + * @param dom output parameter to receive day-of-month (1-based) + * @param dow output parameter to receive day-of-week (1-based, 1==Sun) + * @param doy output parameter to receive day-of-year (1-based) + */ + static void dayToFields(double day, int32_t& year, int32_t& month, + int32_t& dom, int32_t& dow, int32_t& doy); + + /** + * Convert a 1970-epoch day number to proleptic Gregorian year, + * month, day-of-month, and day-of-week. + * @param day 1970-epoch day (integral value) + * @param year output parameter to receive year + * @param month output parameter to receive month (0-based, 0==Jan) + * @param dom output parameter to receive day-of-month (1-based) + * @param dow output parameter to receive day-of-week (1-based, 1==Sun) + */ + static inline void dayToFields(double day, int32_t& year, int32_t& month, + int32_t& dom, int32_t& dow); + + /** + * Convert a 1970-epoch milliseconds to proleptic Gregorian year, + * month, day-of-month, and day-of-week, day of year and millis-in-day. + * @param time 1970-epoch milliseconds + * @param year output parameter to receive year + * @param month output parameter to receive month (0-based, 0==Jan) + * @param dom output parameter to receive day-of-month (1-based) + * @param dow output parameter to receive day-of-week (1-based, 1==Sun) + * @param doy output parameter to receive day-of-year (1-based) + * @param mid output parameter to receive millis-in-day + */ + static void timeToFields(UDate time, int32_t& year, int32_t& month, + int32_t& dom, int32_t& dow, int32_t& doy, int32_t& mid); + + /** + * Return the day of week on the 1970-epoch day + * @param day the 1970-epoch day (integral value) + * @return the day of week + */ + static int32_t dayOfWeek(double day); + + /** + * Returns the ordinal number for the specified day of week within the month. + * The valid return value is 1, 2, 3, 4 or -1. + * @param year Gregorian year, with 0 == 1 BCE, -1 == 2 BCE, etc. + * @param month 0-based month, with 0==Jan + * @param dom 1-based day of month + * @return The ordinal number for the specified day of week within the month + */ + static int32_t dayOfWeekInMonth(int32_t year, int32_t month, int32_t dom); + + /** + * Converts Julian day to time as milliseconds. + * @param julian the given Julian day number. + * @return time as milliseconds. + * @internal + */ + static inline double julianDayToMillis(int32_t julian); + + /** + * Converts time as milliseconds to Julian day. + * @param millis the given milliseconds. + * @return the Julian day number. + * @internal + */ + static inline int32_t millisToJulianDay(double millis); + + /** + * Calculates the Gregorian day shift value for an extended year. + * @param eyear Extended year + * @returns number of days to ADD to Julian in order to convert from J->G + */ + static inline int32_t gregorianShift(int32_t eyear); + + private: + static const int16_t DAYS_BEFORE[24]; + static const int8_t MONTH_LENGTH[24]; +}; + +inline double ClockMath::floorDivide(double numerator, double denominator) { + return uprv_floor(numerator / denominator); +} + +inline UBool Grego::isLeapYear(int32_t year) { + // year&0x3 == year%4 + return ((year&0x3) == 0) && ((year%100 != 0) || (year%400 == 0)); +} + +inline int8_t +Grego::monthLength(int32_t year, int32_t month) { + return MONTH_LENGTH[month + (isLeapYear(year) ? 12 : 0)]; +} + +inline int8_t +Grego::previousMonthLength(int y, int m) { + return (m > 0) ? monthLength(y, m-1) : 31; +} + +inline void Grego::dayToFields(double day, int32_t& year, int32_t& month, + int32_t& dom, int32_t& dow) { + int32_t doy_unused; + dayToFields(day,year,month,dom,dow,doy_unused); +} + +inline double Grego::julianDayToMillis(int32_t julian) +{ + return (julian - kEpochStartAsJulianDay) * kOneDay; +} + +inline int32_t Grego::millisToJulianDay(double millis) { + return (int32_t) (kEpochStartAsJulianDay + ClockMath::floorDivide(millis, (double)kOneDay)); +} + +inline int32_t Grego::gregorianShift(int32_t eyear) { + int64_t y = (int64_t)eyear-1; + int32_t gregShift = static_cast<int32_t>(ClockMath::floorDivide(y, (int64_t)400) - ClockMath::floorDivide(y, (int64_t)100) + 2); + return gregShift; +} + +U_NAMESPACE_END + +#endif // !UCONFIG_NO_FORMATTING +#endif // GREGOIMP_H + +//eof |