1 // Copyright (C) 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 ******************************************************************************
5 * Copyright (C) 2007-2014, International Business Machines Corporation
6 * and others. All Rights Reserved.
7 ******************************************************************************
8 *
9 * File CHNSECAL.CPP
10 *
11 * Modification History:
12 *
13 * Date Name Description
14 * 9/18/2007 ajmacher ported from java ChineseCalendar
15 *****************************************************************************
16 */
17
18 #include "chnsecal.h"
19
20 #if !UCONFIG_NO_FORMATTING
21
22 #include "umutex.h"
23 #include <float.h>
24 #include "gregoimp.h" // Math
25 #include "astro.h" // CalendarAstronomer
26 #include "unicode/simpletz.h"
27 #include "uhash.h"
28 #include "ucln_in.h"
29
30 // Debugging
31 #ifdef U_DEBUG_CHNSECAL
32 # include <stdio.h>
33 # include <stdarg.h>
debug_chnsecal_loc(const char * f,int32_t l)34 static void debug_chnsecal_loc(const char *f, int32_t l)
35 {
36 fprintf(stderr, "%s:%d: ", f, l);
37 }
38
debug_chnsecal_msg(const char * pat,...)39 static void debug_chnsecal_msg(const char *pat, ...)
40 {
41 va_list ap;
42 va_start(ap, pat);
43 vfprintf(stderr, pat, ap);
44 fflush(stderr);
45 }
46 // must use double parens, i.e.: U_DEBUG_CHNSECAL_MSG(("four is: %d",4));
47 #define U_DEBUG_CHNSECAL_MSG(x) {debug_chnsecal_loc(__FILE__,__LINE__);debug_chnsecal_msg x;}
48 #else
49 #define U_DEBUG_CHNSECAL_MSG(x)
50 #endif
51
52
53 // --- The cache --
54 static UMutex astroLock = U_MUTEX_INITIALIZER; // Protects access to gChineseCalendarAstro.
55 static icu::CalendarAstronomer *gChineseCalendarAstro = NULL;
56
57 // Lazy Creation & Access synchronized by class CalendarCache with a mutex.
58 static icu::CalendarCache *gChineseCalendarWinterSolsticeCache = NULL;
59 static icu::CalendarCache *gChineseCalendarNewYearCache = NULL;
60
61 static icu::TimeZone *gChineseCalendarZoneAstroCalc = NULL;
62 static icu::UInitOnce gChineseCalendarZoneAstroCalcInitOnce = U_INITONCE_INITIALIZER;
63
64 /**
65 * The start year of the Chinese calendar, the 61st year of the reign
66 * of Huang Di. Some sources use the first year of his reign,
67 * resulting in EXTENDED_YEAR values 60 years greater and ERA (cycle)
68 * values one greater.
69 */
70 static const int32_t CHINESE_EPOCH_YEAR = -2636; // Gregorian year
71
72 /**
73 * The offset from GMT in milliseconds at which we perform astronomical
74 * computations. Some sources use a different historically accurate
75 * offset of GMT+7:45:40 for years before 1929; we do not do this.
76 */
77 static const int32_t CHINA_OFFSET = 8 * kOneHour;
78
79 /**
80 * Value to be added or subtracted from the local days of a new moon to
81 * get close to the next or prior new moon, but not cross it. Must be
82 * >= 1 and < CalendarAstronomer.SYNODIC_MONTH.
83 */
84 static const int32_t SYNODIC_GAP = 25;
85
86
87 U_CDECL_BEGIN
calendar_chinese_cleanup(void)88 static UBool calendar_chinese_cleanup(void) {
89 if (gChineseCalendarAstro) {
90 delete gChineseCalendarAstro;
91 gChineseCalendarAstro = NULL;
92 }
93 if (gChineseCalendarWinterSolsticeCache) {
94 delete gChineseCalendarWinterSolsticeCache;
95 gChineseCalendarWinterSolsticeCache = NULL;
96 }
97 if (gChineseCalendarNewYearCache) {
98 delete gChineseCalendarNewYearCache;
99 gChineseCalendarNewYearCache = NULL;
100 }
101 if (gChineseCalendarZoneAstroCalc) {
102 delete gChineseCalendarZoneAstroCalc;
103 gChineseCalendarZoneAstroCalc = NULL;
104 }
105 gChineseCalendarZoneAstroCalcInitOnce.reset();
106 return TRUE;
107 }
108 U_CDECL_END
109
110 U_NAMESPACE_BEGIN
111
112
113 // Implementation of the ChineseCalendar class
114
115
116 //-------------------------------------------------------------------------
117 // Constructors...
118 //-------------------------------------------------------------------------
119
120
clone() const121 Calendar* ChineseCalendar::clone() const {
122 return new ChineseCalendar(*this);
123 }
124
ChineseCalendar(const Locale & aLocale,UErrorCode & success)125 ChineseCalendar::ChineseCalendar(const Locale& aLocale, UErrorCode& success)
126 : Calendar(TimeZone::createDefault(), aLocale, success),
127 isLeapYear(FALSE),
128 fEpochYear(CHINESE_EPOCH_YEAR),
129 fZoneAstroCalc(getChineseCalZoneAstroCalc())
130 {
131 setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
132 }
133
ChineseCalendar(const Locale & aLocale,int32_t epochYear,const TimeZone * zoneAstroCalc,UErrorCode & success)134 ChineseCalendar::ChineseCalendar(const Locale& aLocale, int32_t epochYear,
135 const TimeZone* zoneAstroCalc, UErrorCode &success)
136 : Calendar(TimeZone::createDefault(), aLocale, success),
137 isLeapYear(FALSE),
138 fEpochYear(epochYear),
139 fZoneAstroCalc(zoneAstroCalc)
140 {
141 setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
142 }
143
ChineseCalendar(const ChineseCalendar & other)144 ChineseCalendar::ChineseCalendar(const ChineseCalendar& other) : Calendar(other) {
145 isLeapYear = other.isLeapYear;
146 fEpochYear = other.fEpochYear;
147 fZoneAstroCalc = other.fZoneAstroCalc;
148 }
149
~ChineseCalendar()150 ChineseCalendar::~ChineseCalendar()
151 {
152 }
153
getType() const154 const char *ChineseCalendar::getType() const {
155 return "chinese";
156 }
157
initChineseCalZoneAstroCalc()158 static void U_CALLCONV initChineseCalZoneAstroCalc() {
159 gChineseCalendarZoneAstroCalc = new SimpleTimeZone(CHINA_OFFSET, UNICODE_STRING_SIMPLE("CHINA_ZONE") );
160 ucln_i18n_registerCleanup(UCLN_I18N_CHINESE_CALENDAR, calendar_chinese_cleanup);
161 }
162
getChineseCalZoneAstroCalc(void) const163 const TimeZone* ChineseCalendar::getChineseCalZoneAstroCalc(void) const {
164 umtx_initOnce(gChineseCalendarZoneAstroCalcInitOnce, &initChineseCalZoneAstroCalc);
165 return gChineseCalendarZoneAstroCalc;
166 }
167
168 //-------------------------------------------------------------------------
169 // Minimum / Maximum access functions
170 //-------------------------------------------------------------------------
171
172
173 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
174 // Minimum Greatest Least Maximum
175 // Minimum Maximum
176 { 1, 1, 83333, 83333}, // ERA
177 { 1, 1, 60, 60}, // YEAR
178 { 0, 0, 11, 11}, // MONTH
179 { 1, 1, 50, 55}, // WEEK_OF_YEAR
180 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
181 { 1, 1, 29, 30}, // DAY_OF_MONTH
182 { 1, 1, 353, 385}, // DAY_OF_YEAR
183 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
184 { -1, -1, 5, 5}, // DAY_OF_WEEK_IN_MONTH
185 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
186 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
187 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
188 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
189 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
190 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
191 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
192 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
193 { -5000000, -5000000, 5000000, 5000000}, // YEAR_WOY
194 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
195 { -5000000, -5000000, 5000000, 5000000}, // EXTENDED_YEAR
196 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
197 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
198 { 0, 0, 1, 1}, // IS_LEAP_MONTH
199 };
200
201
202 /**
203 * @draft ICU 2.4
204 */
handleGetLimit(UCalendarDateFields field,ELimitType limitType) const205 int32_t ChineseCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
206 return LIMITS[field][limitType];
207 }
208
209
210 //----------------------------------------------------------------------
211 // Calendar framework
212 //----------------------------------------------------------------------
213
214 /**
215 * Implement abstract Calendar method to return the extended year
216 * defined by the current fields. This will use either the ERA and
217 * YEAR field as the cycle and year-of-cycle, or the EXTENDED_YEAR
218 * field as the continuous year count, depending on which is newer.
219 * @stable ICU 2.8
220 */
handleGetExtendedYear()221 int32_t ChineseCalendar::handleGetExtendedYear() {
222 int32_t year;
223 if (newestStamp(UCAL_ERA, UCAL_YEAR, kUnset) <= fStamp[UCAL_EXTENDED_YEAR]) {
224 year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
225 } else {
226 int32_t cycle = internalGet(UCAL_ERA, 1) - 1; // 0-based cycle
227 // adjust to the instance specific epoch
228 year = cycle * 60 + internalGet(UCAL_YEAR, 1) - (fEpochYear - CHINESE_EPOCH_YEAR);
229 }
230 return year;
231 }
232
233 /**
234 * Override Calendar method to return the number of days in the given
235 * extended year and month.
236 *
237 * <p>Note: This method also reads the IS_LEAP_MONTH field to determine
238 * whether or not the given month is a leap month.
239 * @stable ICU 2.8
240 */
handleGetMonthLength(int32_t extendedYear,int32_t month) const241 int32_t ChineseCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
242 int32_t thisStart = handleComputeMonthStart(extendedYear, month, TRUE) -
243 kEpochStartAsJulianDay + 1; // Julian day -> local days
244 int32_t nextStart = newMoonNear(thisStart + SYNODIC_GAP, TRUE);
245 return nextStart - thisStart;
246 }
247
248 /**
249 * Override Calendar to compute several fields specific to the Chinese
250 * calendar system. These are:
251 *
252 * <ul><li>ERA
253 * <li>YEAR
254 * <li>MONTH
255 * <li>DAY_OF_MONTH
256 * <li>DAY_OF_YEAR
257 * <li>EXTENDED_YEAR</ul>
258 *
259 * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
260 * method is called. The getGregorianXxx() methods return Gregorian
261 * calendar equivalents for the given Julian day.
262 *
263 * <p>Compute the ChineseCalendar-specific field IS_LEAP_MONTH.
264 * @stable ICU 2.8
265 */
handleComputeFields(int32_t julianDay,UErrorCode &)266 void ChineseCalendar::handleComputeFields(int32_t julianDay, UErrorCode &/*status*/) {
267
268 computeChineseFields(julianDay - kEpochStartAsJulianDay, // local days
269 getGregorianYear(), getGregorianMonth(),
270 TRUE); // set all fields
271 }
272
273 /**
274 * Field resolution table that incorporates IS_LEAP_MONTH.
275 */
276 const UFieldResolutionTable ChineseCalendar::CHINESE_DATE_PRECEDENCE[] =
277 {
278 {
279 { UCAL_DAY_OF_MONTH, kResolveSTOP },
280 { UCAL_WEEK_OF_YEAR, UCAL_DAY_OF_WEEK, kResolveSTOP },
281 { UCAL_WEEK_OF_MONTH, UCAL_DAY_OF_WEEK, kResolveSTOP },
282 { UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_DAY_OF_WEEK, kResolveSTOP },
283 { UCAL_WEEK_OF_YEAR, UCAL_DOW_LOCAL, kResolveSTOP },
284 { UCAL_WEEK_OF_MONTH, UCAL_DOW_LOCAL, kResolveSTOP },
285 { UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_DOW_LOCAL, kResolveSTOP },
286 { UCAL_DAY_OF_YEAR, kResolveSTOP },
287 { kResolveRemap | UCAL_DAY_OF_MONTH, UCAL_IS_LEAP_MONTH, kResolveSTOP },
288 { kResolveSTOP }
289 },
290 {
291 { UCAL_WEEK_OF_YEAR, kResolveSTOP },
292 { UCAL_WEEK_OF_MONTH, kResolveSTOP },
293 { UCAL_DAY_OF_WEEK_IN_MONTH, kResolveSTOP },
294 { kResolveRemap | UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_DAY_OF_WEEK, kResolveSTOP },
295 { kResolveRemap | UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_DOW_LOCAL, kResolveSTOP },
296 { kResolveSTOP }
297 },
298 {{kResolveSTOP}}
299 };
300
301 /**
302 * Override Calendar to add IS_LEAP_MONTH to the field resolution
303 * table.
304 * @stable ICU 2.8
305 */
getFieldResolutionTable() const306 const UFieldResolutionTable* ChineseCalendar::getFieldResolutionTable() const {
307 return CHINESE_DATE_PRECEDENCE;
308 }
309
310 /**
311 * Return the Julian day number of day before the first day of the
312 * given month in the given extended year.
313 *
314 * <p>Note: This method reads the IS_LEAP_MONTH field to determine
315 * whether the given month is a leap month.
316 * @param eyear the extended year
317 * @param month the zero-based month. The month is also determined
318 * by reading the IS_LEAP_MONTH field.
319 * @return the Julian day number of the day before the first
320 * day of the given month and year
321 * @stable ICU 2.8
322 */
handleComputeMonthStart(int32_t eyear,int32_t month,UBool useMonth) const323 int32_t ChineseCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool useMonth) const {
324
325 ChineseCalendar *nonConstThis = (ChineseCalendar*)this; // cast away const
326
327 // If the month is out of range, adjust it into range, and
328 // modify the extended year value accordingly.
329 if (month < 0 || month > 11) {
330 double m = month;
331 eyear += (int32_t)ClockMath::floorDivide(m, 12.0, m);
332 month = (int32_t)m;
333 }
334
335 int32_t gyear = eyear + fEpochYear - 1; // Gregorian year
336 int32_t theNewYear = newYear(gyear);
337 int32_t newMoon = newMoonNear(theNewYear + month * 29, TRUE);
338
339 int32_t julianDay = newMoon + kEpochStartAsJulianDay;
340
341 // Save fields for later restoration
342 int32_t saveMonth = internalGet(UCAL_MONTH);
343 int32_t saveIsLeapMonth = internalGet(UCAL_IS_LEAP_MONTH);
344
345 // Ignore IS_LEAP_MONTH field if useMonth is false
346 int32_t isLeapMonth = useMonth ? saveIsLeapMonth : 0;
347
348 UErrorCode status = U_ZERO_ERROR;
349 nonConstThis->computeGregorianFields(julianDay, status);
350 if (U_FAILURE(status))
351 return 0;
352
353 // This will modify the MONTH and IS_LEAP_MONTH fields (only)
354 nonConstThis->computeChineseFields(newMoon, getGregorianYear(),
355 getGregorianMonth(), FALSE);
356
357 if (month != internalGet(UCAL_MONTH) ||
358 isLeapMonth != internalGet(UCAL_IS_LEAP_MONTH)) {
359 newMoon = newMoonNear(newMoon + SYNODIC_GAP, TRUE);
360 julianDay = newMoon + kEpochStartAsJulianDay;
361 }
362
363 nonConstThis->internalSet(UCAL_MONTH, saveMonth);
364 nonConstThis->internalSet(UCAL_IS_LEAP_MONTH, saveIsLeapMonth);
365
366 return julianDay - 1;
367 }
368
369
370 /**
371 * Override Calendar to handle leap months properly.
372 * @stable ICU 2.8
373 */
add(UCalendarDateFields field,int32_t amount,UErrorCode & status)374 void ChineseCalendar::add(UCalendarDateFields field, int32_t amount, UErrorCode& status) {
375 switch (field) {
376 case UCAL_MONTH:
377 if (amount != 0) {
378 int32_t dom = get(UCAL_DAY_OF_MONTH, status);
379 if (U_FAILURE(status)) break;
380 int32_t day = get(UCAL_JULIAN_DAY, status) - kEpochStartAsJulianDay; // Get local day
381 if (U_FAILURE(status)) break;
382 int32_t moon = day - dom + 1; // New moon
383 offsetMonth(moon, dom, amount);
384 }
385 break;
386 default:
387 Calendar::add(field, amount, status);
388 break;
389 }
390 }
391
392 /**
393 * Override Calendar to handle leap months properly.
394 * @stable ICU 2.8
395 */
add(EDateFields field,int32_t amount,UErrorCode & status)396 void ChineseCalendar::add(EDateFields field, int32_t amount, UErrorCode& status) {
397 add((UCalendarDateFields)field, amount, status);
398 }
399
400 /**
401 * Override Calendar to handle leap months properly.
402 * @stable ICU 2.8
403 */
roll(UCalendarDateFields field,int32_t amount,UErrorCode & status)404 void ChineseCalendar::roll(UCalendarDateFields field, int32_t amount, UErrorCode& status) {
405 switch (field) {
406 case UCAL_MONTH:
407 if (amount != 0) {
408 int32_t dom = get(UCAL_DAY_OF_MONTH, status);
409 if (U_FAILURE(status)) break;
410 int32_t day = get(UCAL_JULIAN_DAY, status) - kEpochStartAsJulianDay; // Get local day
411 if (U_FAILURE(status)) break;
412 int32_t moon = day - dom + 1; // New moon (start of this month)
413
414 // Note throughout the following: Months 12 and 1 are never
415 // followed by a leap month (D&R p. 185).
416
417 // Compute the adjusted month number m. This is zero-based
418 // value from 0..11 in a non-leap year, and from 0..12 in a
419 // leap year.
420 int32_t m = get(UCAL_MONTH, status); // 0-based month
421 if (U_FAILURE(status)) break;
422 if (isLeapYear) { // (member variable)
423 if (get(UCAL_IS_LEAP_MONTH, status) == 1) {
424 ++m;
425 } else {
426 // Check for a prior leap month. (In the
427 // following, month 0 is the first month of the
428 // year.) Month 0 is never followed by a leap
429 // month, and we know month m is not a leap month.
430 // moon1 will be the start of month 0 if there is
431 // no leap month between month 0 and month m;
432 // otherwise it will be the start of month 1.
433 int moon1 = moon -
434 (int) (CalendarAstronomer::SYNODIC_MONTH * (m - 0.5));
435 moon1 = newMoonNear(moon1, TRUE);
436 if (isLeapMonthBetween(moon1, moon)) {
437 ++m;
438 }
439 }
440 if (U_FAILURE(status)) break;
441 }
442
443 // Now do the standard roll computation on m, with the
444 // allowed range of 0..n-1, where n is 12 or 13.
445 int32_t n = isLeapYear ? 13 : 12; // Months in this year
446 int32_t newM = (m + amount) % n;
447 if (newM < 0) {
448 newM += n;
449 }
450
451 if (newM != m) {
452 offsetMonth(moon, dom, newM - m);
453 }
454 }
455 break;
456 default:
457 Calendar::roll(field, amount, status);
458 break;
459 }
460 }
461
roll(EDateFields field,int32_t amount,UErrorCode & status)462 void ChineseCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) {
463 roll((UCalendarDateFields)field, amount, status);
464 }
465
466
467 //------------------------------------------------------------------
468 // Support methods and constants
469 //------------------------------------------------------------------
470
471 /**
472 * Convert local days to UTC epoch milliseconds.
473 * This is not an accurate conversion in that getTimezoneOffset
474 * takes the milliseconds in GMT (not local time). In theory, more
475 * accurate algorithm can be implemented but practically we do not need
476 * to go through that complication as long as the historical timezone
477 * changes did not happen around the 'tricky' new moon (new moon around
478 * midnight).
479 *
480 * @param days days after January 1, 1970 0:00 in the astronomical base zone
481 * @return milliseconds after January 1, 1970 0:00 GMT
482 */
daysToMillis(double days) const483 double ChineseCalendar::daysToMillis(double days) const {
484 double millis = days * (double)kOneDay;
485 if (fZoneAstroCalc != NULL) {
486 int32_t rawOffset, dstOffset;
487 UErrorCode status = U_ZERO_ERROR;
488 fZoneAstroCalc->getOffset(millis, FALSE, rawOffset, dstOffset, status);
489 if (U_SUCCESS(status)) {
490 return millis - (double)(rawOffset + dstOffset);
491 }
492 }
493 return millis - (double)CHINA_OFFSET;
494 }
495
496 /**
497 * Convert UTC epoch milliseconds to local days.
498 * @param millis milliseconds after January 1, 1970 0:00 GMT
499 * @return days after January 1, 1970 0:00 in the astronomical base zone
500 */
millisToDays(double millis) const501 double ChineseCalendar::millisToDays(double millis) const {
502 if (fZoneAstroCalc != NULL) {
503 int32_t rawOffset, dstOffset;
504 UErrorCode status = U_ZERO_ERROR;
505 fZoneAstroCalc->getOffset(millis, FALSE, rawOffset, dstOffset, status);
506 if (U_SUCCESS(status)) {
507 return ClockMath::floorDivide(millis + (double)(rawOffset + dstOffset), kOneDay);
508 }
509 }
510 return ClockMath::floorDivide(millis + (double)CHINA_OFFSET, kOneDay);
511 }
512
513 //------------------------------------------------------------------
514 // Astronomical computations
515 //------------------------------------------------------------------
516
517
518 /**
519 * Return the major solar term on or after December 15 of the given
520 * Gregorian year, that is, the winter solstice of the given year.
521 * Computations are relative to Asia/Shanghai time zone.
522 * @param gyear a Gregorian year
523 * @return days after January 1, 1970 0:00 Asia/Shanghai of the
524 * winter solstice of the given year
525 */
winterSolstice(int32_t gyear) const526 int32_t ChineseCalendar::winterSolstice(int32_t gyear) const {
527
528 UErrorCode status = U_ZERO_ERROR;
529 int32_t cacheValue = CalendarCache::get(&gChineseCalendarWinterSolsticeCache, gyear, status);
530
531 if (cacheValue == 0) {
532 // In books December 15 is used, but it fails for some years
533 // using our algorithms, e.g.: 1298 1391 1492 1553 1560. That
534 // is, winterSolstice(1298) starts search at Dec 14 08:00:00
535 // PST 1298 with a final result of Dec 14 10:31:59 PST 1299.
536 double ms = daysToMillis(Grego::fieldsToDay(gyear, UCAL_DECEMBER, 1));
537
538 umtx_lock(&astroLock);
539 if(gChineseCalendarAstro == NULL) {
540 gChineseCalendarAstro = new CalendarAstronomer();
541 ucln_i18n_registerCleanup(UCLN_I18N_CHINESE_CALENDAR, calendar_chinese_cleanup);
542 }
543 gChineseCalendarAstro->setTime(ms);
544 UDate solarLong = gChineseCalendarAstro->getSunTime(CalendarAstronomer::WINTER_SOLSTICE(), TRUE);
545 umtx_unlock(&astroLock);
546
547 // Winter solstice is 270 degrees solar longitude aka Dongzhi
548 cacheValue = (int32_t)millisToDays(solarLong);
549 CalendarCache::put(&gChineseCalendarWinterSolsticeCache, gyear, cacheValue, status);
550 }
551 if(U_FAILURE(status)) {
552 cacheValue = 0;
553 }
554 return cacheValue;
555 }
556
557 /**
558 * Return the closest new moon to the given date, searching either
559 * forward or backward in time.
560 * @param days days after January 1, 1970 0:00 Asia/Shanghai
561 * @param after if true, search for a new moon on or after the given
562 * date; otherwise, search for a new moon before it
563 * @return days after January 1, 1970 0:00 Asia/Shanghai of the nearest
564 * new moon after or before <code>days</code>
565 */
newMoonNear(double days,UBool after) const566 int32_t ChineseCalendar::newMoonNear(double days, UBool after) const {
567
568 umtx_lock(&astroLock);
569 if(gChineseCalendarAstro == NULL) {
570 gChineseCalendarAstro = new CalendarAstronomer();
571 ucln_i18n_registerCleanup(UCLN_I18N_CHINESE_CALENDAR, calendar_chinese_cleanup);
572 }
573 gChineseCalendarAstro->setTime(daysToMillis(days));
574 UDate newMoon = gChineseCalendarAstro->getMoonTime(CalendarAstronomer::NEW_MOON(), after);
575 umtx_unlock(&astroLock);
576
577 return (int32_t) millisToDays(newMoon);
578 }
579
580 /**
581 * Return the nearest integer number of synodic months between
582 * two dates.
583 * @param day1 days after January 1, 1970 0:00 Asia/Shanghai
584 * @param day2 days after January 1, 1970 0:00 Asia/Shanghai
585 * @return the nearest integer number of months between day1 and day2
586 */
synodicMonthsBetween(int32_t day1,int32_t day2) const587 int32_t ChineseCalendar::synodicMonthsBetween(int32_t day1, int32_t day2) const {
588 double roundme = ((day2 - day1) / CalendarAstronomer::SYNODIC_MONTH);
589 return (int32_t) (roundme + (roundme >= 0 ? .5 : -.5));
590 }
591
592 /**
593 * Return the major solar term on or before a given date. This
594 * will be an integer from 1..12, with 1 corresponding to 330 degrees,
595 * 2 to 0 degrees, 3 to 30 degrees,..., and 12 to 300 degrees.
596 * @param days days after January 1, 1970 0:00 Asia/Shanghai
597 */
majorSolarTerm(int32_t days) const598 int32_t ChineseCalendar::majorSolarTerm(int32_t days) const {
599
600 umtx_lock(&astroLock);
601 if(gChineseCalendarAstro == NULL) {
602 gChineseCalendarAstro = new CalendarAstronomer();
603 ucln_i18n_registerCleanup(UCLN_I18N_CHINESE_CALENDAR, calendar_chinese_cleanup);
604 }
605 gChineseCalendarAstro->setTime(daysToMillis(days));
606 UDate solarLongitude = gChineseCalendarAstro->getSunLongitude();
607 umtx_unlock(&astroLock);
608
609 // Compute (floor(solarLongitude / (pi/6)) + 2) % 12
610 int32_t term = ( ((int32_t)(6 * solarLongitude / CalendarAstronomer::PI)) + 2 ) % 12;
611 if (term < 1) {
612 term += 12;
613 }
614 return term;
615 }
616
617 /**
618 * Return true if the given month lacks a major solar term.
619 * @param newMoon days after January 1, 1970 0:00 Asia/Shanghai of a new
620 * moon
621 */
hasNoMajorSolarTerm(int32_t newMoon) const622 UBool ChineseCalendar::hasNoMajorSolarTerm(int32_t newMoon) const {
623 return majorSolarTerm(newMoon) ==
624 majorSolarTerm(newMoonNear(newMoon + SYNODIC_GAP, TRUE));
625 }
626
627
628 //------------------------------------------------------------------
629 // Time to fields
630 //------------------------------------------------------------------
631
632 /**
633 * Return true if there is a leap month on or after month newMoon1 and
634 * at or before month newMoon2.
635 * @param newMoon1 days after January 1, 1970 0:00 astronomical base zone
636 * of a new moon
637 * @param newMoon2 days after January 1, 1970 0:00 astronomical base zone
638 * of a new moon
639 */
isLeapMonthBetween(int32_t newMoon1,int32_t newMoon2) const640 UBool ChineseCalendar::isLeapMonthBetween(int32_t newMoon1, int32_t newMoon2) const {
641
642 #ifdef U_DEBUG_CHNSECAL
643 // This is only needed to debug the timeOfAngle divergence bug.
644 // Remove this later. Liu 11/9/00
645 if (synodicMonthsBetween(newMoon1, newMoon2) >= 50) {
646 U_DEBUG_CHNSECAL_MSG((
647 "isLeapMonthBetween(%d, %d): Invalid parameters", newMoon1, newMoon2
648 ));
649 }
650 #endif
651
652 return (newMoon2 >= newMoon1) &&
653 (isLeapMonthBetween(newMoon1, newMoonNear(newMoon2 - SYNODIC_GAP, FALSE)) ||
654 hasNoMajorSolarTerm(newMoon2));
655 }
656
657 /**
658 * Compute fields for the Chinese calendar system. This method can
659 * either set all relevant fields, as required by
660 * <code>handleComputeFields()</code>, or it can just set the MONTH and
661 * IS_LEAP_MONTH fields, as required by
662 * <code>handleComputeMonthStart()</code>.
663 *
664 * <p>As a side effect, this method sets {@link #isLeapYear}.
665 * @param days days after January 1, 1970 0:00 astronomical base zone
666 * of the date to compute fields for
667 * @param gyear the Gregorian year of the given date
668 * @param gmonth the Gregorian month of the given date
669 * @param setAllFields if true, set the EXTENDED_YEAR, ERA, YEAR,
670 * DAY_OF_MONTH, and DAY_OF_YEAR fields. In either case set the MONTH
671 * and IS_LEAP_MONTH fields.
672 */
computeChineseFields(int32_t days,int32_t gyear,int32_t gmonth,UBool setAllFields)673 void ChineseCalendar::computeChineseFields(int32_t days, int32_t gyear, int32_t gmonth,
674 UBool setAllFields) {
675
676 // Find the winter solstices before and after the target date.
677 // These define the boundaries of this Chinese year, specifically,
678 // the position of month 11, which always contains the solstice.
679 // We want solsticeBefore <= date < solsticeAfter.
680 int32_t solsticeBefore;
681 int32_t solsticeAfter = winterSolstice(gyear);
682 if (days < solsticeAfter) {
683 solsticeBefore = winterSolstice(gyear - 1);
684 } else {
685 solsticeBefore = solsticeAfter;
686 solsticeAfter = winterSolstice(gyear + 1);
687 }
688
689 // Find the start of the month after month 11. This will be either
690 // the prior month 12 or leap month 11 (very rare). Also find the
691 // start of the following month 11.
692 int32_t firstMoon = newMoonNear(solsticeBefore + 1, TRUE);
693 int32_t lastMoon = newMoonNear(solsticeAfter + 1, FALSE);
694 int32_t thisMoon = newMoonNear(days + 1, FALSE); // Start of this month
695 // Note: isLeapYear is a member variable
696 isLeapYear = synodicMonthsBetween(firstMoon, lastMoon) == 12;
697
698 int32_t month = synodicMonthsBetween(firstMoon, thisMoon);
699 if (isLeapYear && isLeapMonthBetween(firstMoon, thisMoon)) {
700 month--;
701 }
702 if (month < 1) {
703 month += 12;
704 }
705
706 UBool isLeapMonth = isLeapYear &&
707 hasNoMajorSolarTerm(thisMoon) &&
708 !isLeapMonthBetween(firstMoon, newMoonNear(thisMoon - SYNODIC_GAP, FALSE));
709
710 internalSet(UCAL_MONTH, month-1); // Convert from 1-based to 0-based
711 internalSet(UCAL_IS_LEAP_MONTH, isLeapMonth?1:0);
712
713 if (setAllFields) {
714
715 // Extended year and cycle year is based on the epoch year
716
717 int32_t extended_year = gyear - fEpochYear;
718 int cycle_year = gyear - CHINESE_EPOCH_YEAR;
719 if (month < 11 ||
720 gmonth >= UCAL_JULY) {
721 extended_year++;
722 cycle_year++;
723 }
724 int32_t dayOfMonth = days - thisMoon + 1;
725
726 internalSet(UCAL_EXTENDED_YEAR, extended_year);
727
728 // 0->0,60 1->1,1 60->1,60 61->2,1 etc.
729 int32_t yearOfCycle;
730 int32_t cycle = ClockMath::floorDivide(cycle_year - 1, 60, yearOfCycle);
731 internalSet(UCAL_ERA, cycle + 1);
732 internalSet(UCAL_YEAR, yearOfCycle + 1);
733
734 internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
735
736 // Days will be before the first new year we compute if this
737 // date is in month 11, leap 11, 12. There is never a leap 12.
738 // New year computations are cached so this should be cheap in
739 // the long run.
740 int32_t theNewYear = newYear(gyear);
741 if (days < theNewYear) {
742 theNewYear = newYear(gyear-1);
743 }
744 internalSet(UCAL_DAY_OF_YEAR, days - theNewYear + 1);
745 }
746 }
747
748
749 //------------------------------------------------------------------
750 // Fields to time
751 //------------------------------------------------------------------
752
753 /**
754 * Return the Chinese new year of the given Gregorian year.
755 * @param gyear a Gregorian year
756 * @return days after January 1, 1970 0:00 astronomical base zone of the
757 * Chinese new year of the given year (this will be a new moon)
758 */
newYear(int32_t gyear) const759 int32_t ChineseCalendar::newYear(int32_t gyear) const {
760 UErrorCode status = U_ZERO_ERROR;
761 int32_t cacheValue = CalendarCache::get(&gChineseCalendarNewYearCache, gyear, status);
762
763 if (cacheValue == 0) {
764
765 int32_t solsticeBefore= winterSolstice(gyear - 1);
766 int32_t solsticeAfter = winterSolstice(gyear);
767 int32_t newMoon1 = newMoonNear(solsticeBefore + 1, TRUE);
768 int32_t newMoon2 = newMoonNear(newMoon1 + SYNODIC_GAP, TRUE);
769 int32_t newMoon11 = newMoonNear(solsticeAfter + 1, FALSE);
770
771 if (synodicMonthsBetween(newMoon1, newMoon11) == 12 &&
772 (hasNoMajorSolarTerm(newMoon1) || hasNoMajorSolarTerm(newMoon2))) {
773 cacheValue = newMoonNear(newMoon2 + SYNODIC_GAP, TRUE);
774 } else {
775 cacheValue = newMoon2;
776 }
777
778 CalendarCache::put(&gChineseCalendarNewYearCache, gyear, cacheValue, status);
779 }
780 if(U_FAILURE(status)) {
781 cacheValue = 0;
782 }
783 return cacheValue;
784 }
785
786 /**
787 * Adjust this calendar to be delta months before or after a given
788 * start position, pinning the day of month if necessary. The start
789 * position is given as a local days number for the start of the month
790 * and a day-of-month. Used by add() and roll().
791 * @param newMoon the local days of the first day of the month of the
792 * start position (days after January 1, 1970 0:00 Asia/Shanghai)
793 * @param dom the 1-based day-of-month of the start position
794 * @param delta the number of months to move forward or backward from
795 * the start position
796 */
offsetMonth(int32_t newMoon,int32_t dom,int32_t delta)797 void ChineseCalendar::offsetMonth(int32_t newMoon, int32_t dom, int32_t delta) {
798 UErrorCode status = U_ZERO_ERROR;
799
800 // Move to the middle of the month before our target month.
801 newMoon += (int32_t) (CalendarAstronomer::SYNODIC_MONTH * (delta - 0.5));
802
803 // Search forward to the target month's new moon
804 newMoon = newMoonNear(newMoon, TRUE);
805
806 // Find the target dom
807 int32_t jd = newMoon + kEpochStartAsJulianDay - 1 + dom;
808
809 // Pin the dom. In this calendar all months are 29 or 30 days
810 // so pinning just means handling dom 30.
811 if (dom > 29) {
812 set(UCAL_JULIAN_DAY, jd-1);
813 // TODO Fix this. We really shouldn't ever have to
814 // explicitly call complete(). This is either a bug in
815 // this method, in ChineseCalendar, or in
816 // Calendar.getActualMaximum(). I suspect the last.
817 complete(status);
818 if (U_FAILURE(status)) return;
819 if (getActualMaximum(UCAL_DAY_OF_MONTH, status) >= dom) {
820 if (U_FAILURE(status)) return;
821 set(UCAL_JULIAN_DAY, jd);
822 }
823 } else {
824 set(UCAL_JULIAN_DAY, jd);
825 }
826 }
827
828
829 UBool
inDaylightTime(UErrorCode & status) const830 ChineseCalendar::inDaylightTime(UErrorCode& status) const
831 {
832 // copied from GregorianCalendar
833 if (U_FAILURE(status) || !getTimeZone().useDaylightTime())
834 return FALSE;
835
836 // Force an update of the state of the Calendar.
837 ((ChineseCalendar*)this)->complete(status); // cast away const
838
839 return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
840 }
841
842 // default century
843
844 static UDate gSystemDefaultCenturyStart = DBL_MIN;
845 static int32_t gSystemDefaultCenturyStartYear = -1;
846 static icu::UInitOnce gSystemDefaultCenturyInitOnce = U_INITONCE_INITIALIZER;
847
848
haveDefaultCentury() const849 UBool ChineseCalendar::haveDefaultCentury() const
850 {
851 return TRUE;
852 }
853
defaultCenturyStart() const854 UDate ChineseCalendar::defaultCenturyStart() const
855 {
856 return internalGetDefaultCenturyStart();
857 }
858
defaultCenturyStartYear() const859 int32_t ChineseCalendar::defaultCenturyStartYear() const
860 {
861 return internalGetDefaultCenturyStartYear();
862 }
863
initializeSystemDefaultCentury()864 static void U_CALLCONV initializeSystemDefaultCentury()
865 {
866 // initialize systemDefaultCentury and systemDefaultCenturyYear based
867 // on the current time. They'll be set to 80 years before
868 // the current time.
869 UErrorCode status = U_ZERO_ERROR;
870 ChineseCalendar calendar(Locale("@calendar=chinese"),status);
871 if (U_SUCCESS(status)) {
872 calendar.setTime(Calendar::getNow(), status);
873 calendar.add(UCAL_YEAR, -80, status);
874 gSystemDefaultCenturyStart = calendar.getTime(status);
875 gSystemDefaultCenturyStartYear = calendar.get(UCAL_YEAR, status);
876 }
877 // We have no recourse upon failure unless we want to propagate the failure
878 // out.
879 }
880
881 UDate
internalGetDefaultCenturyStart() const882 ChineseCalendar::internalGetDefaultCenturyStart() const
883 {
884 // lazy-evaluate systemDefaultCenturyStart
885 umtx_initOnce(gSystemDefaultCenturyInitOnce, &initializeSystemDefaultCentury);
886 return gSystemDefaultCenturyStart;
887 }
888
889 int32_t
internalGetDefaultCenturyStartYear() const890 ChineseCalendar::internalGetDefaultCenturyStartYear() const
891 {
892 // lazy-evaluate systemDefaultCenturyStartYear
893 umtx_initOnce(gSystemDefaultCenturyInitOnce, &initializeSystemDefaultCentury);
894 return gSystemDefaultCenturyStartYear;
895 }
896
897 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ChineseCalendar)
898
899 U_NAMESPACE_END
900
901 #endif
902
903