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Diffstat (limited to 'intl/icu/source/i18n/chnsecal.cpp')
| -rw-r--r-- | intl/icu/source/i18n/chnsecal.cpp | 902 |
1 files changed, 902 insertions, 0 deletions
diff --git a/intl/icu/source/i18n/chnsecal.cpp b/intl/icu/source/i18n/chnsecal.cpp new file mode 100644 index 000000000..4de390abc --- /dev/null +++ b/intl/icu/source/i18n/chnsecal.cpp @@ -0,0 +1,902 @@ +// Copyright (C) 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* + ****************************************************************************** + * Copyright (C) 2007-2014, International Business Machines Corporation + * and others. All Rights Reserved. + ****************************************************************************** + * + * File CHNSECAL.CPP + * + * Modification History: + * + * Date Name Description + * 9/18/2007 ajmacher ported from java ChineseCalendar + ***************************************************************************** + */ + +#include "chnsecal.h" + +#if !UCONFIG_NO_FORMATTING + +#include "umutex.h" +#include <float.h> +#include "gregoimp.h" // Math +#include "astro.h" // CalendarAstronomer +#include "unicode/simpletz.h" +#include "uhash.h" +#include "ucln_in.h" + +// Debugging +#ifdef U_DEBUG_CHNSECAL +# include <stdio.h> +# include <stdarg.h> +static void debug_chnsecal_loc(const char *f, int32_t l) +{ + fprintf(stderr, "%s:%d: ", f, l); +} + +static void debug_chnsecal_msg(const char *pat, ...) +{ + va_list ap; + va_start(ap, pat); + vfprintf(stderr, pat, ap); + fflush(stderr); +} +// must use double parens, i.e.: U_DEBUG_CHNSECAL_MSG(("four is: %d",4)); +#define U_DEBUG_CHNSECAL_MSG(x) {debug_chnsecal_loc(__FILE__,__LINE__);debug_chnsecal_msg x;} +#else +#define U_DEBUG_CHNSECAL_MSG(x) +#endif + + +// --- The cache -- +static UMutex astroLock = U_MUTEX_INITIALIZER; // Protects access to gChineseCalendarAstro. +static icu::CalendarAstronomer *gChineseCalendarAstro = NULL; + +// Lazy Creation & Access synchronized by class CalendarCache with a mutex. +static icu::CalendarCache *gChineseCalendarWinterSolsticeCache = NULL; +static icu::CalendarCache *gChineseCalendarNewYearCache = NULL; + +static icu::TimeZone *gChineseCalendarZoneAstroCalc = NULL; +static icu::UInitOnce gChineseCalendarZoneAstroCalcInitOnce = U_INITONCE_INITIALIZER; + +/** + * The start year of the Chinese calendar, the 61st year of the reign + * of Huang Di. Some sources use the first year of his reign, + * resulting in EXTENDED_YEAR values 60 years greater and ERA (cycle) + * values one greater. + */ +static const int32_t CHINESE_EPOCH_YEAR = -2636; // Gregorian year + +/** + * The offset from GMT in milliseconds at which we perform astronomical + * computations. Some sources use a different historically accurate + * offset of GMT+7:45:40 for years before 1929; we do not do this. + */ +static const int32_t CHINA_OFFSET = 8 * kOneHour; + +/** + * Value to be added or subtracted from the local days of a new moon to + * get close to the next or prior new moon, but not cross it. Must be + * >= 1 and < CalendarAstronomer.SYNODIC_MONTH. + */ +static const int32_t SYNODIC_GAP = 25; + + +U_CDECL_BEGIN +static UBool calendar_chinese_cleanup(void) { + if (gChineseCalendarAstro) { + delete gChineseCalendarAstro; + gChineseCalendarAstro = NULL; + } + if (gChineseCalendarWinterSolsticeCache) { + delete gChineseCalendarWinterSolsticeCache; + gChineseCalendarWinterSolsticeCache = NULL; + } + if (gChineseCalendarNewYearCache) { + delete gChineseCalendarNewYearCache; + gChineseCalendarNewYearCache = NULL; + } + if (gChineseCalendarZoneAstroCalc) { + delete gChineseCalendarZoneAstroCalc; + gChineseCalendarZoneAstroCalc = NULL; + } + gChineseCalendarZoneAstroCalcInitOnce.reset(); + return TRUE; +} +U_CDECL_END + +U_NAMESPACE_BEGIN + + +// Implementation of the ChineseCalendar class + + +//------------------------------------------------------------------------- +// Constructors... +//------------------------------------------------------------------------- + + +Calendar* ChineseCalendar::clone() const { + return new ChineseCalendar(*this); +} + +ChineseCalendar::ChineseCalendar(const Locale& aLocale, UErrorCode& success) +: Calendar(TimeZone::createDefault(), aLocale, success), + isLeapYear(FALSE), + fEpochYear(CHINESE_EPOCH_YEAR), + fZoneAstroCalc(getChineseCalZoneAstroCalc()) +{ + setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly. +} + +ChineseCalendar::ChineseCalendar(const Locale& aLocale, int32_t epochYear, + const TimeZone* zoneAstroCalc, UErrorCode &success) +: Calendar(TimeZone::createDefault(), aLocale, success), + isLeapYear(FALSE), + fEpochYear(epochYear), + fZoneAstroCalc(zoneAstroCalc) +{ + setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly. +} + +ChineseCalendar::ChineseCalendar(const ChineseCalendar& other) : Calendar(other) { + isLeapYear = other.isLeapYear; + fEpochYear = other.fEpochYear; + fZoneAstroCalc = other.fZoneAstroCalc; +} + +ChineseCalendar::~ChineseCalendar() +{ +} + +const char *ChineseCalendar::getType() const { + return "chinese"; +} + +static void U_CALLCONV initChineseCalZoneAstroCalc() { + gChineseCalendarZoneAstroCalc = new SimpleTimeZone(CHINA_OFFSET, UNICODE_STRING_SIMPLE("CHINA_ZONE") ); + ucln_i18n_registerCleanup(UCLN_I18N_CHINESE_CALENDAR, calendar_chinese_cleanup); +} + +const TimeZone* ChineseCalendar::getChineseCalZoneAstroCalc(void) const { + umtx_initOnce(gChineseCalendarZoneAstroCalcInitOnce, &initChineseCalZoneAstroCalc); + return gChineseCalendarZoneAstroCalc; +} + +//------------------------------------------------------------------------- +// Minimum / Maximum access functions +//------------------------------------------------------------------------- + + +static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = { + // Minimum Greatest Least Maximum + // Minimum Maximum + { 1, 1, 83333, 83333}, // ERA + { 1, 1, 60, 60}, // YEAR + { 0, 0, 11, 11}, // MONTH + { 1, 1, 50, 55}, // WEEK_OF_YEAR + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH + { 1, 1, 29, 30}, // DAY_OF_MONTH + { 1, 1, 353, 385}, // DAY_OF_YEAR + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK + { -1, -1, 5, 5}, // DAY_OF_WEEK_IN_MONTH + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET + { -5000000, -5000000, 5000000, 5000000}, // YEAR_WOY + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL + { -5000000, -5000000, 5000000, 5000000}, // EXTENDED_YEAR + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY + {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY + { 0, 0, 1, 1}, // IS_LEAP_MONTH +}; + + +/** +* @draft ICU 2.4 +*/ +int32_t ChineseCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const { + return LIMITS[field][limitType]; +} + + +//---------------------------------------------------------------------- +// Calendar framework +//---------------------------------------------------------------------- + +/** + * Implement abstract Calendar method to return the extended year + * defined by the current fields. This will use either the ERA and + * YEAR field as the cycle and year-of-cycle, or the EXTENDED_YEAR + * field as the continuous year count, depending on which is newer. + * @stable ICU 2.8 + */ +int32_t ChineseCalendar::handleGetExtendedYear() { + int32_t year; + if (newestStamp(UCAL_ERA, UCAL_YEAR, kUnset) <= fStamp[UCAL_EXTENDED_YEAR]) { + year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1 + } else { + int32_t cycle = internalGet(UCAL_ERA, 1) - 1; // 0-based cycle + // adjust to the instance specific epoch + year = cycle * 60 + internalGet(UCAL_YEAR, 1) - (fEpochYear - CHINESE_EPOCH_YEAR); + } + return year; +} + +/** + * Override Calendar method to return the number of days in the given + * extended year and month. + * + * <p>Note: This method also reads the IS_LEAP_MONTH field to determine + * whether or not the given month is a leap month. + * @stable ICU 2.8 + */ +int32_t ChineseCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const { + int32_t thisStart = handleComputeMonthStart(extendedYear, month, TRUE) - + kEpochStartAsJulianDay + 1; // Julian day -> local days + int32_t nextStart = newMoonNear(thisStart + SYNODIC_GAP, TRUE); + return nextStart - thisStart; +} + +/** + * Override Calendar to compute several fields specific to the Chinese + * calendar system. These are: + * + * <ul><li>ERA + * <li>YEAR + * <li>MONTH + * <li>DAY_OF_MONTH + * <li>DAY_OF_YEAR + * <li>EXTENDED_YEAR</ul> + * + * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this + * method is called. The getGregorianXxx() methods return Gregorian + * calendar equivalents for the given Julian day. + * + * <p>Compute the ChineseCalendar-specific field IS_LEAP_MONTH. + * @stable ICU 2.8 + */ +void ChineseCalendar::handleComputeFields(int32_t julianDay, UErrorCode &/*status*/) { + + computeChineseFields(julianDay - kEpochStartAsJulianDay, // local days + getGregorianYear(), getGregorianMonth(), + TRUE); // set all fields +} + +/** + * Field resolution table that incorporates IS_LEAP_MONTH. + */ +const UFieldResolutionTable ChineseCalendar::CHINESE_DATE_PRECEDENCE[] = +{ + { + { UCAL_DAY_OF_MONTH, kResolveSTOP }, + { UCAL_WEEK_OF_YEAR, UCAL_DAY_OF_WEEK, kResolveSTOP }, + { UCAL_WEEK_OF_MONTH, UCAL_DAY_OF_WEEK, kResolveSTOP }, + { UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_DAY_OF_WEEK, kResolveSTOP }, + { UCAL_WEEK_OF_YEAR, UCAL_DOW_LOCAL, kResolveSTOP }, + { UCAL_WEEK_OF_MONTH, UCAL_DOW_LOCAL, kResolveSTOP }, + { UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_DOW_LOCAL, kResolveSTOP }, + { UCAL_DAY_OF_YEAR, kResolveSTOP }, + { kResolveRemap | UCAL_DAY_OF_MONTH, UCAL_IS_LEAP_MONTH, kResolveSTOP }, + { kResolveSTOP } + }, + { + { UCAL_WEEK_OF_YEAR, kResolveSTOP }, + { UCAL_WEEK_OF_MONTH, kResolveSTOP }, + { UCAL_DAY_OF_WEEK_IN_MONTH, kResolveSTOP }, + { kResolveRemap | UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_DAY_OF_WEEK, kResolveSTOP }, + { kResolveRemap | UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_DOW_LOCAL, kResolveSTOP }, + { kResolveSTOP } + }, + {{kResolveSTOP}} +}; + +/** + * Override Calendar to add IS_LEAP_MONTH to the field resolution + * table. + * @stable ICU 2.8 + */ +const UFieldResolutionTable* ChineseCalendar::getFieldResolutionTable() const { + return CHINESE_DATE_PRECEDENCE; +} + +/** + * Return the Julian day number of day before the first day of the + * given month in the given extended year. + * + * <p>Note: This method reads the IS_LEAP_MONTH field to determine + * whether the given month is a leap month. + * @param eyear the extended year + * @param month the zero-based month. The month is also determined + * by reading the IS_LEAP_MONTH field. + * @return the Julian day number of the day before the first + * day of the given month and year + * @stable ICU 2.8 + */ +int32_t ChineseCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool useMonth) const { + + ChineseCalendar *nonConstThis = (ChineseCalendar*)this; // cast away const + + // If the month is out of range, adjust it into range, and + // modify the extended year value accordingly. + if (month < 0 || month > 11) { + double m = month; + eyear += (int32_t)ClockMath::floorDivide(m, 12.0, m); + month = (int32_t)m; + } + + int32_t gyear = eyear + fEpochYear - 1; // Gregorian year + int32_t theNewYear = newYear(gyear); + int32_t newMoon = newMoonNear(theNewYear + month * 29, TRUE); + + int32_t julianDay = newMoon + kEpochStartAsJulianDay; + + // Save fields for later restoration + int32_t saveMonth = internalGet(UCAL_MONTH); + int32_t saveIsLeapMonth = internalGet(UCAL_IS_LEAP_MONTH); + + // Ignore IS_LEAP_MONTH field if useMonth is false + int32_t isLeapMonth = useMonth ? saveIsLeapMonth : 0; + + UErrorCode status = U_ZERO_ERROR; + nonConstThis->computeGregorianFields(julianDay, status); + if (U_FAILURE(status)) + return 0; + + // This will modify the MONTH and IS_LEAP_MONTH fields (only) + nonConstThis->computeChineseFields(newMoon, getGregorianYear(), + getGregorianMonth(), FALSE); + + if (month != internalGet(UCAL_MONTH) || + isLeapMonth != internalGet(UCAL_IS_LEAP_MONTH)) { + newMoon = newMoonNear(newMoon + SYNODIC_GAP, TRUE); + julianDay = newMoon + kEpochStartAsJulianDay; + } + + nonConstThis->internalSet(UCAL_MONTH, saveMonth); + nonConstThis->internalSet(UCAL_IS_LEAP_MONTH, saveIsLeapMonth); + + return julianDay - 1; +} + + +/** + * Override Calendar to handle leap months properly. + * @stable ICU 2.8 + */ +void ChineseCalendar::add(UCalendarDateFields field, int32_t amount, UErrorCode& status) { + switch (field) { + case UCAL_MONTH: + if (amount != 0) { + int32_t dom = get(UCAL_DAY_OF_MONTH, status); + if (U_FAILURE(status)) break; + int32_t day = get(UCAL_JULIAN_DAY, status) - kEpochStartAsJulianDay; // Get local day + if (U_FAILURE(status)) break; + int32_t moon = day - dom + 1; // New moon + offsetMonth(moon, dom, amount); + } + break; + default: + Calendar::add(field, amount, status); + break; + } +} + +/** + * Override Calendar to handle leap months properly. + * @stable ICU 2.8 + */ +void ChineseCalendar::add(EDateFields field, int32_t amount, UErrorCode& status) { + add((UCalendarDateFields)field, amount, status); +} + +/** + * Override Calendar to handle leap months properly. + * @stable ICU 2.8 + */ +void ChineseCalendar::roll(UCalendarDateFields field, int32_t amount, UErrorCode& status) { + switch (field) { + case UCAL_MONTH: + if (amount != 0) { + int32_t dom = get(UCAL_DAY_OF_MONTH, status); + if (U_FAILURE(status)) break; + int32_t day = get(UCAL_JULIAN_DAY, status) - kEpochStartAsJulianDay; // Get local day + if (U_FAILURE(status)) break; + int32_t moon = day - dom + 1; // New moon (start of this month) + + // Note throughout the following: Months 12 and 1 are never + // followed by a leap month (D&R p. 185). + + // Compute the adjusted month number m. This is zero-based + // value from 0..11 in a non-leap year, and from 0..12 in a + // leap year. + int32_t m = get(UCAL_MONTH, status); // 0-based month + if (U_FAILURE(status)) break; + if (isLeapYear) { // (member variable) + if (get(UCAL_IS_LEAP_MONTH, status) == 1) { + ++m; + } else { + // Check for a prior leap month. (In the + // following, month 0 is the first month of the + // year.) Month 0 is never followed by a leap + // month, and we know month m is not a leap month. + // moon1 will be the start of month 0 if there is + // no leap month between month 0 and month m; + // otherwise it will be the start of month 1. + int moon1 = moon - + (int) (CalendarAstronomer::SYNODIC_MONTH * (m - 0.5)); + moon1 = newMoonNear(moon1, TRUE); + if (isLeapMonthBetween(moon1, moon)) { + ++m; + } + } + if (U_FAILURE(status)) break; + } + + // Now do the standard roll computation on m, with the + // allowed range of 0..n-1, where n is 12 or 13. + int32_t n = isLeapYear ? 13 : 12; // Months in this year + int32_t newM = (m + amount) % n; + if (newM < 0) { + newM += n; + } + + if (newM != m) { + offsetMonth(moon, dom, newM - m); + } + } + break; + default: + Calendar::roll(field, amount, status); + break; + } +} + +void ChineseCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) { + roll((UCalendarDateFields)field, amount, status); +} + + +//------------------------------------------------------------------ +// Support methods and constants +//------------------------------------------------------------------ + +/** + * Convert local days to UTC epoch milliseconds. + * This is not an accurate conversion in that getTimezoneOffset + * takes the milliseconds in GMT (not local time). In theory, more + * accurate algorithm can be implemented but practically we do not need + * to go through that complication as long as the historical timezone + * changes did not happen around the 'tricky' new moon (new moon around + * midnight). + * + * @param days days after January 1, 1970 0:00 in the astronomical base zone + * @return milliseconds after January 1, 1970 0:00 GMT + */ +double ChineseCalendar::daysToMillis(double days) const { + double millis = days * (double)kOneDay; + if (fZoneAstroCalc != NULL) { + int32_t rawOffset, dstOffset; + UErrorCode status = U_ZERO_ERROR; + fZoneAstroCalc->getOffset(millis, FALSE, rawOffset, dstOffset, status); + if (U_SUCCESS(status)) { + return millis - (double)(rawOffset + dstOffset); + } + } + return millis - (double)CHINA_OFFSET; +} + +/** + * Convert UTC epoch milliseconds to local days. + * @param millis milliseconds after January 1, 1970 0:00 GMT + * @return days after January 1, 1970 0:00 in the astronomical base zone + */ +double ChineseCalendar::millisToDays(double millis) const { + if (fZoneAstroCalc != NULL) { + int32_t rawOffset, dstOffset; + UErrorCode status = U_ZERO_ERROR; + fZoneAstroCalc->getOffset(millis, FALSE, rawOffset, dstOffset, status); + if (U_SUCCESS(status)) { + return ClockMath::floorDivide(millis + (double)(rawOffset + dstOffset), kOneDay); + } + } + return ClockMath::floorDivide(millis + (double)CHINA_OFFSET, kOneDay); +} + +//------------------------------------------------------------------ +// Astronomical computations +//------------------------------------------------------------------ + + +/** + * Return the major solar term on or after December 15 of the given + * Gregorian year, that is, the winter solstice of the given year. + * Computations are relative to Asia/Shanghai time zone. + * @param gyear a Gregorian year + * @return days after January 1, 1970 0:00 Asia/Shanghai of the + * winter solstice of the given year + */ +int32_t ChineseCalendar::winterSolstice(int32_t gyear) const { + + UErrorCode status = U_ZERO_ERROR; + int32_t cacheValue = CalendarCache::get(&gChineseCalendarWinterSolsticeCache, gyear, status); + + if (cacheValue == 0) { + // In books December 15 is used, but it fails for some years + // using our algorithms, e.g.: 1298 1391 1492 1553 1560. That + // is, winterSolstice(1298) starts search at Dec 14 08:00:00 + // PST 1298 with a final result of Dec 14 10:31:59 PST 1299. + double ms = daysToMillis(Grego::fieldsToDay(gyear, UCAL_DECEMBER, 1)); + + umtx_lock(&astroLock); + if(gChineseCalendarAstro == NULL) { + gChineseCalendarAstro = new CalendarAstronomer(); + ucln_i18n_registerCleanup(UCLN_I18N_CHINESE_CALENDAR, calendar_chinese_cleanup); + } + gChineseCalendarAstro->setTime(ms); + UDate solarLong = gChineseCalendarAstro->getSunTime(CalendarAstronomer::WINTER_SOLSTICE(), TRUE); + umtx_unlock(&astroLock); + + // Winter solstice is 270 degrees solar longitude aka Dongzhi + cacheValue = (int32_t)millisToDays(solarLong); + CalendarCache::put(&gChineseCalendarWinterSolsticeCache, gyear, cacheValue, status); + } + if(U_FAILURE(status)) { + cacheValue = 0; + } + return cacheValue; +} + +/** + * Return the closest new moon to the given date, searching either + * forward or backward in time. + * @param days days after January 1, 1970 0:00 Asia/Shanghai + * @param after if true, search for a new moon on or after the given + * date; otherwise, search for a new moon before it + * @return days after January 1, 1970 0:00 Asia/Shanghai of the nearest + * new moon after or before <code>days</code> + */ +int32_t ChineseCalendar::newMoonNear(double days, UBool after) const { + + umtx_lock(&astroLock); + if(gChineseCalendarAstro == NULL) { + gChineseCalendarAstro = new CalendarAstronomer(); + ucln_i18n_registerCleanup(UCLN_I18N_CHINESE_CALENDAR, calendar_chinese_cleanup); + } + gChineseCalendarAstro->setTime(daysToMillis(days)); + UDate newMoon = gChineseCalendarAstro->getMoonTime(CalendarAstronomer::NEW_MOON(), after); + umtx_unlock(&astroLock); + + return (int32_t) millisToDays(newMoon); +} + +/** + * Return the nearest integer number of synodic months between + * two dates. + * @param day1 days after January 1, 1970 0:00 Asia/Shanghai + * @param day2 days after January 1, 1970 0:00 Asia/Shanghai + * @return the nearest integer number of months between day1 and day2 + */ +int32_t ChineseCalendar::synodicMonthsBetween(int32_t day1, int32_t day2) const { + double roundme = ((day2 - day1) / CalendarAstronomer::SYNODIC_MONTH); + return (int32_t) (roundme + (roundme >= 0 ? .5 : -.5)); +} + +/** + * Return the major solar term on or before a given date. This + * will be an integer from 1..12, with 1 corresponding to 330 degrees, + * 2 to 0 degrees, 3 to 30 degrees,..., and 12 to 300 degrees. + * @param days days after January 1, 1970 0:00 Asia/Shanghai + */ +int32_t ChineseCalendar::majorSolarTerm(int32_t days) const { + + umtx_lock(&astroLock); + if(gChineseCalendarAstro == NULL) { + gChineseCalendarAstro = new CalendarAstronomer(); + ucln_i18n_registerCleanup(UCLN_I18N_CHINESE_CALENDAR, calendar_chinese_cleanup); + } + gChineseCalendarAstro->setTime(daysToMillis(days)); + UDate solarLongitude = gChineseCalendarAstro->getSunLongitude(); + umtx_unlock(&astroLock); + + // Compute (floor(solarLongitude / (pi/6)) + 2) % 12 + int32_t term = ( ((int32_t)(6 * solarLongitude / CalendarAstronomer::PI)) + 2 ) % 12; + if (term < 1) { + term += 12; + } + return term; +} + +/** + * Return true if the given month lacks a major solar term. + * @param newMoon days after January 1, 1970 0:00 Asia/Shanghai of a new + * moon + */ +UBool ChineseCalendar::hasNoMajorSolarTerm(int32_t newMoon) const { + return majorSolarTerm(newMoon) == + majorSolarTerm(newMoonNear(newMoon + SYNODIC_GAP, TRUE)); +} + + +//------------------------------------------------------------------ +// Time to fields +//------------------------------------------------------------------ + +/** + * Return true if there is a leap month on or after month newMoon1 and + * at or before month newMoon2. + * @param newMoon1 days after January 1, 1970 0:00 astronomical base zone + * of a new moon + * @param newMoon2 days after January 1, 1970 0:00 astronomical base zone + * of a new moon + */ +UBool ChineseCalendar::isLeapMonthBetween(int32_t newMoon1, int32_t newMoon2) const { + +#ifdef U_DEBUG_CHNSECAL + // This is only needed to debug the timeOfAngle divergence bug. + // Remove this later. Liu 11/9/00 + if (synodicMonthsBetween(newMoon1, newMoon2) >= 50) { + U_DEBUG_CHNSECAL_MSG(( + "isLeapMonthBetween(%d, %d): Invalid parameters", newMoon1, newMoon2 + )); + } +#endif + + return (newMoon2 >= newMoon1) && + (isLeapMonthBetween(newMoon1, newMoonNear(newMoon2 - SYNODIC_GAP, FALSE)) || + hasNoMajorSolarTerm(newMoon2)); +} + +/** + * Compute fields for the Chinese calendar system. This method can + * either set all relevant fields, as required by + * <code>handleComputeFields()</code>, or it can just set the MONTH and + * IS_LEAP_MONTH fields, as required by + * <code>handleComputeMonthStart()</code>. + * + * <p>As a side effect, this method sets {@link #isLeapYear}. + * @param days days after January 1, 1970 0:00 astronomical base zone + * of the date to compute fields for + * @param gyear the Gregorian year of the given date + * @param gmonth the Gregorian month of the given date + * @param setAllFields if true, set the EXTENDED_YEAR, ERA, YEAR, + * DAY_OF_MONTH, and DAY_OF_YEAR fields. In either case set the MONTH + * and IS_LEAP_MONTH fields. + */ +void ChineseCalendar::computeChineseFields(int32_t days, int32_t gyear, int32_t gmonth, + UBool setAllFields) { + + // Find the winter solstices before and after the target date. + // These define the boundaries of this Chinese year, specifically, + // the position of month 11, which always contains the solstice. + // We want solsticeBefore <= date < solsticeAfter. + int32_t solsticeBefore; + int32_t solsticeAfter = winterSolstice(gyear); + if (days < solsticeAfter) { + solsticeBefore = winterSolstice(gyear - 1); + } else { + solsticeBefore = solsticeAfter; + solsticeAfter = winterSolstice(gyear + 1); + } + + // Find the start of the month after month 11. This will be either + // the prior month 12 or leap month 11 (very rare). Also find the + // start of the following month 11. + int32_t firstMoon = newMoonNear(solsticeBefore + 1, TRUE); + int32_t lastMoon = newMoonNear(solsticeAfter + 1, FALSE); + int32_t thisMoon = newMoonNear(days + 1, FALSE); // Start of this month + // Note: isLeapYear is a member variable + isLeapYear = synodicMonthsBetween(firstMoon, lastMoon) == 12; + + int32_t month = synodicMonthsBetween(firstMoon, thisMoon); + if (isLeapYear && isLeapMonthBetween(firstMoon, thisMoon)) { + month--; + } + if (month < 1) { + month += 12; + } + + UBool isLeapMonth = isLeapYear && + hasNoMajorSolarTerm(thisMoon) && + !isLeapMonthBetween(firstMoon, newMoonNear(thisMoon - SYNODIC_GAP, FALSE)); + + internalSet(UCAL_MONTH, month-1); // Convert from 1-based to 0-based + internalSet(UCAL_IS_LEAP_MONTH, isLeapMonth?1:0); + + if (setAllFields) { + + // Extended year and cycle year is based on the epoch year + + int32_t extended_year = gyear - fEpochYear; + int cycle_year = gyear - CHINESE_EPOCH_YEAR; + if (month < 11 || + gmonth >= UCAL_JULY) { + extended_year++; + cycle_year++; + } + int32_t dayOfMonth = days - thisMoon + 1; + + internalSet(UCAL_EXTENDED_YEAR, extended_year); + + // 0->0,60 1->1,1 60->1,60 61->2,1 etc. + int32_t yearOfCycle; + int32_t cycle = ClockMath::floorDivide(cycle_year - 1, 60, yearOfCycle); + internalSet(UCAL_ERA, cycle + 1); + internalSet(UCAL_YEAR, yearOfCycle + 1); + + internalSet(UCAL_DAY_OF_MONTH, dayOfMonth); + + // Days will be before the first new year we compute if this + // date is in month 11, leap 11, 12. There is never a leap 12. + // New year computations are cached so this should be cheap in + // the long run. + int32_t theNewYear = newYear(gyear); + if (days < theNewYear) { + theNewYear = newYear(gyear-1); + } + internalSet(UCAL_DAY_OF_YEAR, days - theNewYear + 1); + } +} + + +//------------------------------------------------------------------ +// Fields to time +//------------------------------------------------------------------ + +/** + * Return the Chinese new year of the given Gregorian year. + * @param gyear a Gregorian year + * @return days after January 1, 1970 0:00 astronomical base zone of the + * Chinese new year of the given year (this will be a new moon) + */ +int32_t ChineseCalendar::newYear(int32_t gyear) const { + UErrorCode status = U_ZERO_ERROR; + int32_t cacheValue = CalendarCache::get(&gChineseCalendarNewYearCache, gyear, status); + + if (cacheValue == 0) { + + int32_t solsticeBefore= winterSolstice(gyear - 1); + int32_t solsticeAfter = winterSolstice(gyear); + int32_t newMoon1 = newMoonNear(solsticeBefore + 1, TRUE); + int32_t newMoon2 = newMoonNear(newMoon1 + SYNODIC_GAP, TRUE); + int32_t newMoon11 = newMoonNear(solsticeAfter + 1, FALSE); + + if (synodicMonthsBetween(newMoon1, newMoon11) == 12 && + (hasNoMajorSolarTerm(newMoon1) || hasNoMajorSolarTerm(newMoon2))) { + cacheValue = newMoonNear(newMoon2 + SYNODIC_GAP, TRUE); + } else { + cacheValue = newMoon2; + } + + CalendarCache::put(&gChineseCalendarNewYearCache, gyear, cacheValue, status); + } + if(U_FAILURE(status)) { + cacheValue = 0; + } + return cacheValue; +} + +/** + * Adjust this calendar to be delta months before or after a given + * start position, pinning the day of month if necessary. The start + * position is given as a local days number for the start of the month + * and a day-of-month. Used by add() and roll(). + * @param newMoon the local days of the first day of the month of the + * start position (days after January 1, 1970 0:00 Asia/Shanghai) + * @param dom the 1-based day-of-month of the start position + * @param delta the number of months to move forward or backward from + * the start position + */ +void ChineseCalendar::offsetMonth(int32_t newMoon, int32_t dom, int32_t delta) { + UErrorCode status = U_ZERO_ERROR; + + // Move to the middle of the month before our target month. + newMoon += (int32_t) (CalendarAstronomer::SYNODIC_MONTH * (delta - 0.5)); + + // Search forward to the target month's new moon + newMoon = newMoonNear(newMoon, TRUE); + + // Find the target dom + int32_t jd = newMoon + kEpochStartAsJulianDay - 1 + dom; + + // Pin the dom. In this calendar all months are 29 or 30 days + // so pinning just means handling dom 30. + if (dom > 29) { + set(UCAL_JULIAN_DAY, jd-1); + // TODO Fix this. We really shouldn't ever have to + // explicitly call complete(). This is either a bug in + // this method, in ChineseCalendar, or in + // Calendar.getActualMaximum(). I suspect the last. + complete(status); + if (U_FAILURE(status)) return; + if (getActualMaximum(UCAL_DAY_OF_MONTH, status) >= dom) { + if (U_FAILURE(status)) return; + set(UCAL_JULIAN_DAY, jd); + } + } else { + set(UCAL_JULIAN_DAY, jd); + } +} + + +UBool +ChineseCalendar::inDaylightTime(UErrorCode& status) const +{ + // copied from GregorianCalendar + if (U_FAILURE(status) || !getTimeZone().useDaylightTime()) + return FALSE; + + // Force an update of the state of the Calendar. + ((ChineseCalendar*)this)->complete(status); // cast away const + + return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE); +} + +// default century + +static UDate gSystemDefaultCenturyStart = DBL_MIN; +static int32_t gSystemDefaultCenturyStartYear = -1; +static icu::UInitOnce gSystemDefaultCenturyInitOnce = U_INITONCE_INITIALIZER; + + +UBool ChineseCalendar::haveDefaultCentury() const +{ + return TRUE; +} + +UDate ChineseCalendar::defaultCenturyStart() const +{ + return internalGetDefaultCenturyStart(); +} + +int32_t ChineseCalendar::defaultCenturyStartYear() const +{ + return internalGetDefaultCenturyStartYear(); +} + +static void U_CALLCONV initializeSystemDefaultCentury() +{ + // initialize systemDefaultCentury and systemDefaultCenturyYear based + // on the current time. They'll be set to 80 years before + // the current time. + UErrorCode status = U_ZERO_ERROR; + ChineseCalendar calendar(Locale("@calendar=chinese"),status); + if (U_SUCCESS(status)) { + calendar.setTime(Calendar::getNow(), status); + calendar.add(UCAL_YEAR, -80, status); + gSystemDefaultCenturyStart = calendar.getTime(status); + gSystemDefaultCenturyStartYear = calendar.get(UCAL_YEAR, status); + } + // We have no recourse upon failure unless we want to propagate the failure + // out. +} + +UDate +ChineseCalendar::internalGetDefaultCenturyStart() const +{ + // lazy-evaluate systemDefaultCenturyStart + umtx_initOnce(gSystemDefaultCenturyInitOnce, &initializeSystemDefaultCentury); + return gSystemDefaultCenturyStart; +} + +int32_t +ChineseCalendar::internalGetDefaultCenturyStartYear() const +{ + // lazy-evaluate systemDefaultCenturyStartYear + umtx_initOnce(gSystemDefaultCenturyInitOnce, &initializeSystemDefaultCentury); + return gSystemDefaultCenturyStartYear; +} + +UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ChineseCalendar) + +U_NAMESPACE_END + +#endif + |