The Tor Browser: intl/icu/source/i18n/chnsecal.cpp@b8a032363ba2 (annotated)

intl/icu/source/i18n/chnsecal.cpp@b8a032363ba2 (annotated)

intl/icu/source/i18n/chnsecal.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
  ******************************************************************************
  * Copyright (C) 2007-2013, 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;  // pod bay door lock
 static icu::CalendarAstronomer *gChineseCalendarAstro = NULL;
 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

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intl/icu/source/i18n/chnsecal.cpp@b8a032363ba2 (annotated)

intl/icu/source/i18n/chnsecal.cpp