/* ********************************************************************** * Copyright (c) 2003-2007, 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. */ class Math { 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 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 * (divident >> 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 recieve 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 Math::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 + Math::floorDivide(millis, (double)kOneDay)); } inline int32_t Grego::gregorianShift(int32_t eyear) { int32_t y = eyear-1; int32_t gregShift = Math::floorDivide(y, 400) - Math::floorDivide(y, 100) + 2; return gregShift; } /** * This utility class provides convenient access to the data needed for a calendar. * @internal ICU 3.0 */ class CalendarData : public UMemory { public: /** * Construct a CalendarData from the given locale. * @param loc locale to use. The 'calendar' keyword will be ignored. * @param type calendar type. NULL indicates the gregorian calendar. * No default lookup is done. * @param status error code */ CalendarData(const Locale& loc, const char *type, UErrorCode& status); /** * Load data for calendar. Note, this object owns the resources, do NOT call ures_close()! * The ResourceBundle C++ API should NOT be used because it is too slow for a low level API. * * @param key Resource key to data * @param status Error Status * @internal */ UResourceBundle* getByKey(const char *key, UErrorCode& status); /** * Load data for calendar. Note, this object owns the resources, do NOT call ures_close()! * There is an implicit key of 'format' * data is located in: "calendar/key/format/subKey" * for example, calendar/dayNames/format/abbreviated * The ResourceBundle C++ API should NOT be used because it is too slow for a low level API. * * @param key Resource key to data * @param subKey Resource key to data * @param status Error Status * @internal */ UResourceBundle* getByKey2(const char *key, const char *subKey, UErrorCode& status); /** * Load data for calendar. Note, this object owns the resources, do NOT call ures_close()! * data is located in: "calendar/key/contextKey/subKey" * for example, calendar/dayNames/standalone/narrow * The ResourceBundle C++ API should NOT be used because it is too slow for a low level API. * * @param key Resource key to data * @param contextKey Resource key to data * @param subKey Resource key to data * @param status Error Status * @internal */ UResourceBundle* getByKey3(const char *key, const char *contextKey, const char *subKey, UErrorCode& status); ~CalendarData(); private: void initData(const char *locale, const char *type, UErrorCode& status); UResourceBundle *fFillin; UResourceBundle *fOtherFillin; UResourceBundle *fBundle; UResourceBundle *fFallback; CalendarData(); // Not implemented. }; U_NAMESPACE_END #endif // !UCONFIG_NO_FORMATTING #endif // GREGOIMP_H //eof