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scuffed-code/icu4c/source/i18n/chnsecal.cpp
Andy Heninger 242e02c388 ICU-12764 icu4c utf-8 source files, update Copyright notices. 
X-SVN-Rev: 39583
2017-01-20 00:20:31 +00:00

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// © 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
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