/*
**********************************************************************
* 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 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 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) {
int32_t y = eyear-1;
int32_t gregShift = ClockMath::floorDivide(y, 400) - ClockMath::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