1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 *******************************************************************************
5 * Copyright (C) 1997-2016, International Business Machines Corporation and
6 * others. All Rights Reserved.
7 *******************************************************************************
8 *
9 * File GREGOCAL.CPP
10 *
11 * Modification History:
12 *
13 * Date Name Description
14 * 02/05/97 clhuang Creation.
15 * 03/28/97 aliu Made highly questionable fix to computeFields to
16 * handle DST correctly.
17 * 04/22/97 aliu Cleaned up code drastically. Added monthLength().
18 * Finished unimplemented parts of computeTime() for
19 * week-based date determination. Removed quetionable
20 * fix and wrote correct fix for computeFields() and
21 * daylight time handling. Rewrote inDaylightTime()
22 * and computeFields() to handle sensitive Daylight to
23 * Standard time transitions correctly.
24 * 05/08/97 aliu Added code review changes. Fixed isLeapYear() to
25 * not cutover.
26 * 08/12/97 aliu Added equivalentTo. Misc other fixes. Updated
27 * add() from Java source.
28 * 07/28/98 stephen Sync up with JDK 1.2
29 * 09/14/98 stephen Changed type of kOneDay, kOneWeek to double.
30 * Fixed bug in roll()
31 * 10/15/99 aliu Fixed j31, incorrect WEEK_OF_YEAR computation.
32 * 10/15/99 aliu Fixed j32, cannot set date to Feb 29 2000 AD.
33 * {JDK bug 4210209 4209272}
34 * 11/15/99 weiv Added YEAR_WOY and DOW_LOCAL computation
35 * to timeToFields method, updated kMinValues, kMaxValues & kLeastMaxValues
36 * 12/09/99 aliu Fixed j81, calculation errors and roll bugs
37 * in year of cutover.
38 * 01/24/2000 aliu Revised computeJulianDay for YEAR YEAR_WOY WOY.
39 ********************************************************************************
40 */
41
42 #include "unicode/utypes.h"
43 #include <float.h>
44
45 #if !UCONFIG_NO_FORMATTING
46
47 #include "unicode/gregocal.h"
48 #include "gregoimp.h"
49 #include "umutex.h"
50 #include "uassert.h"
51
52 // *****************************************************************************
53 // class GregorianCalendar
54 // *****************************************************************************
55
56 /**
57 * Note that the Julian date used here is not a true Julian date, since
58 * it is measured from midnight, not noon. This value is the Julian
59 * day number of January 1, 1970 (Gregorian calendar) at noon UTC. [LIU]
60 */
61
62 static const int16_t kNumDays[]
63 = {0,31,59,90,120,151,181,212,243,273,304,334}; // 0-based, for day-in-year
64 static const int16_t kLeapNumDays[]
65 = {0,31,60,91,121,152,182,213,244,274,305,335}; // 0-based, for day-in-year
66 static const int8_t kMonthLength[]
67 = {31,28,31,30,31,30,31,31,30,31,30,31}; // 0-based
68 static const int8_t kLeapMonthLength[]
69 = {31,29,31,30,31,30,31,31,30,31,30,31}; // 0-based
70
71 // setTimeInMillis() limits the Julian day range to +/-7F000000.
72 // This would seem to limit the year range to:
73 // ms=+183882168921600000 jd=7f000000 December 20, 5828963 AD
74 // ms=-184303902528000000 jd=81000000 September 20, 5838270 BC
75 // HOWEVER, CalendarRegressionTest/Test4167060 shows that the actual
76 // range limit on the year field is smaller (~ +/-140000). [alan 3.0]
77
78 static const int32_t kGregorianCalendarLimits[UCAL_FIELD_COUNT][4] = {
79 // Minimum Greatest Least Maximum
80 // Minimum Maximum
81 { 0, 0, 1, 1}, // ERA
82 { 1, 1, 140742, 144683}, // YEAR
83 { 0, 0, 11, 11}, // MONTH
84 { 1, 1, 52, 53}, // WEEK_OF_YEAR
85 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
86 { 1, 1, 28, 31}, // DAY_OF_MONTH
87 { 1, 1, 365, 366}, // DAY_OF_YEAR
88 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
89 { -1, -1, 4, 5}, // DAY_OF_WEEK_IN_MONTH
90 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
91 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
92 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
93 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
94 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
95 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
96 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
97 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
98 { -140742, -140742, 140742, 144683}, // YEAR_WOY
99 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
100 { -140742, -140742, 140742, 144683}, // EXTENDED_YEAR
101 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
102 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
103 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
104 { 0, 0, 11, 11}, // ORDINAL_MONTH
105 };
106
107 /*
108 * <pre>
109 * Greatest Least
110 * Field name Minimum Minimum Maximum Maximum
111 * ---------- ------- ------- ------- -------
112 * ERA 0 0 1 1
113 * YEAR 1 1 140742 144683
114 * MONTH 0 0 11 11
115 * WEEK_OF_YEAR 1 1 52 53
116 * WEEK_OF_MONTH 0 0 4 6
117 * DAY_OF_MONTH 1 1 28 31
118 * DAY_OF_YEAR 1 1 365 366
119 * DAY_OF_WEEK 1 1 7 7
120 * DAY_OF_WEEK_IN_MONTH -1 -1 4 5
121 * AM_PM 0 0 1 1
122 * HOUR 0 0 11 11
123 * HOUR_OF_DAY 0 0 23 23
124 * MINUTE 0 0 59 59
125 * SECOND 0 0 59 59
126 * MILLISECOND 0 0 999 999
127 * ZONE_OFFSET -12* -12* 12* 12*
128 * DST_OFFSET 0 0 1* 1*
129 * YEAR_WOY 1 1 140742 144683
130 * DOW_LOCAL 1 1 7 7
131 * </pre>
132 * (*) In units of one-hour
133 */
134
135 #if defined( U_DEBUG_CALSVC ) || defined (U_DEBUG_CAL)
136 #include <stdio.h>
137 #endif
138
139 U_NAMESPACE_BEGIN
140
141 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(GregorianCalendar)
142
143 // 00:00:00 UTC, October 15, 1582, expressed in ms from the epoch.
144 // Note that only Italy and other Catholic countries actually
145 // observed this cutover. Most other countries followed in
146 // the next few centuries, some as late as 1928. [LIU]
147 // in Java, -12219292800000L
148 //const UDate GregorianCalendar::kPapalCutover = -12219292800000L;
149 static const uint32_t kCutoverJulianDay = 2299161;
150 static const UDate kPapalCutover = (2299161.0 - kEpochStartAsJulianDay) * U_MILLIS_PER_DAY;
151 //static const UDate kPapalCutoverJulian = (2299161.0 - kEpochStartAsJulianDay);
152
153 // -------------------------------------
154
GregorianCalendar(UErrorCode & status)155 GregorianCalendar::GregorianCalendar(UErrorCode& status)
156 : Calendar(status),
157 fGregorianCutover(kPapalCutover),
158 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
159 fIsGregorian(true), fInvertGregorian(false)
160 {
161 setTimeInMillis(getNow(), status);
162 }
163
164 // -------------------------------------
165
GregorianCalendar(TimeZone * zone,UErrorCode & status)166 GregorianCalendar::GregorianCalendar(TimeZone* zone, UErrorCode& status)
167 : Calendar(zone, Locale::getDefault(), status),
168 fGregorianCutover(kPapalCutover),
169 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
170 fIsGregorian(true), fInvertGregorian(false)
171 {
172 setTimeInMillis(getNow(), status);
173 }
174
175 // -------------------------------------
176
GregorianCalendar(const TimeZone & zone,UErrorCode & status)177 GregorianCalendar::GregorianCalendar(const TimeZone& zone, UErrorCode& status)
178 : Calendar(zone, Locale::getDefault(), status),
179 fGregorianCutover(kPapalCutover),
180 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
181 fIsGregorian(true), fInvertGregorian(false)
182 {
183 setTimeInMillis(getNow(), status);
184 }
185
186 // -------------------------------------
187
GregorianCalendar(const Locale & aLocale,UErrorCode & status)188 GregorianCalendar::GregorianCalendar(const Locale& aLocale, UErrorCode& status)
189 : Calendar(TimeZone::forLocaleOrDefault(aLocale), aLocale, status),
190 fGregorianCutover(kPapalCutover),
191 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
192 fIsGregorian(true), fInvertGregorian(false)
193 {
194 setTimeInMillis(getNow(), status);
195 }
196
197 // -------------------------------------
198
GregorianCalendar(TimeZone * zone,const Locale & aLocale,UErrorCode & status)199 GregorianCalendar::GregorianCalendar(TimeZone* zone, const Locale& aLocale,
200 UErrorCode& status)
201 : Calendar(zone, aLocale, status),
202 fGregorianCutover(kPapalCutover),
203 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
204 fIsGregorian(true), fInvertGregorian(false)
205 {
206 setTimeInMillis(getNow(), status);
207 }
208
209 // -------------------------------------
210
GregorianCalendar(const TimeZone & zone,const Locale & aLocale,UErrorCode & status)211 GregorianCalendar::GregorianCalendar(const TimeZone& zone, const Locale& aLocale,
212 UErrorCode& status)
213 : Calendar(zone, aLocale, status),
214 fGregorianCutover(kPapalCutover),
215 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
216 fIsGregorian(true), fInvertGregorian(false)
217 {
218 setTimeInMillis(getNow(), status);
219 }
220
221 // -------------------------------------
222
GregorianCalendar(int32_t year,int32_t month,int32_t date,UErrorCode & status)223 GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
224 UErrorCode& status)
225 : Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
226 fGregorianCutover(kPapalCutover),
227 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
228 fIsGregorian(true), fInvertGregorian(false)
229 {
230 set(UCAL_ERA, AD);
231 set(UCAL_YEAR, year);
232 set(UCAL_MONTH, month);
233 set(UCAL_DATE, date);
234 }
235
236 // -------------------------------------
237
GregorianCalendar(int32_t year,int32_t month,int32_t date,int32_t hour,int32_t minute,UErrorCode & status)238 GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
239 int32_t hour, int32_t minute, UErrorCode& status)
240 : Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
241 fGregorianCutover(kPapalCutover),
242 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
243 fIsGregorian(true), fInvertGregorian(false)
244 {
245 set(UCAL_ERA, AD);
246 set(UCAL_YEAR, year);
247 set(UCAL_MONTH, month);
248 set(UCAL_DATE, date);
249 set(UCAL_HOUR_OF_DAY, hour);
250 set(UCAL_MINUTE, minute);
251 }
252
253 // -------------------------------------
254
GregorianCalendar(int32_t year,int32_t month,int32_t date,int32_t hour,int32_t minute,int32_t second,UErrorCode & status)255 GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
256 int32_t hour, int32_t minute, int32_t second,
257 UErrorCode& status)
258 : Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
259 fGregorianCutover(kPapalCutover),
260 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
261 fIsGregorian(true), fInvertGregorian(false)
262 {
263 set(UCAL_ERA, AD);
264 set(UCAL_YEAR, year);
265 set(UCAL_MONTH, month);
266 set(UCAL_DATE, date);
267 set(UCAL_HOUR_OF_DAY, hour);
268 set(UCAL_MINUTE, minute);
269 set(UCAL_SECOND, second);
270 }
271
272 // -------------------------------------
273
~GregorianCalendar()274 GregorianCalendar::~GregorianCalendar()
275 {
276 }
277
278 // -------------------------------------
279
GregorianCalendar(const GregorianCalendar & source)280 GregorianCalendar::GregorianCalendar(const GregorianCalendar &source)
281 : Calendar(source),
282 fGregorianCutover(source.fGregorianCutover),
283 fCutoverJulianDay(source.fCutoverJulianDay), fNormalizedGregorianCutover(source.fNormalizedGregorianCutover), fGregorianCutoverYear(source.fGregorianCutoverYear),
284 fIsGregorian(source.fIsGregorian), fInvertGregorian(source.fInvertGregorian)
285 {
286 }
287
288 // -------------------------------------
289
clone() const290 GregorianCalendar* GregorianCalendar::clone() const
291 {
292 return new GregorianCalendar(*this);
293 }
294
295 // -------------------------------------
296
297 GregorianCalendar &
operator =(const GregorianCalendar & right)298 GregorianCalendar::operator=(const GregorianCalendar &right)
299 {
300 if (this != &right)
301 {
302 Calendar::operator=(right);
303 fGregorianCutover = right.fGregorianCutover;
304 fNormalizedGregorianCutover = right.fNormalizedGregorianCutover;
305 fGregorianCutoverYear = right.fGregorianCutoverYear;
306 fCutoverJulianDay = right.fCutoverJulianDay;
307 }
308 return *this;
309 }
310
311 // -------------------------------------
312
isEquivalentTo(const Calendar & other) const313 UBool GregorianCalendar::isEquivalentTo(const Calendar& other) const
314 {
315 // Calendar override.
316 return Calendar::isEquivalentTo(other) &&
317 fGregorianCutover == ((GregorianCalendar*)&other)->fGregorianCutover;
318 }
319
320 // -------------------------------------
321
322 void
setGregorianChange(UDate date,UErrorCode & status)323 GregorianCalendar::setGregorianChange(UDate date, UErrorCode& status)
324 {
325 if (U_FAILURE(status))
326 return;
327
328 // Precompute two internal variables which we use to do the actual
329 // cutover computations. These are the normalized cutover, which is the
330 // midnight at or before the cutover, and the cutover year. The
331 // normalized cutover is in pure date milliseconds; it contains no time
332 // of day or timezone component, and it used to compare against other
333 // pure date values.
334 double cutoverDay = ClockMath::floorDivide(date, (double)kOneDay);
335
336 // Handle the rare case of numeric overflow where the user specifies a time
337 // outside of INT32_MIN .. INT32_MAX number of days.
338
339 if (cutoverDay <= INT32_MIN) {
340 cutoverDay = INT32_MIN;
341 fGregorianCutover = fNormalizedGregorianCutover = cutoverDay * kOneDay;
342 } else if (cutoverDay >= INT32_MAX) {
343 cutoverDay = INT32_MAX;
344 fGregorianCutover = fNormalizedGregorianCutover = cutoverDay * kOneDay;
345 } else {
346 fNormalizedGregorianCutover = cutoverDay * kOneDay;
347 fGregorianCutover = date;
348 }
349
350 // Normalize the year so BC values are represented as 0 and negative
351 // values.
352 GregorianCalendar *cal = new GregorianCalendar(getTimeZone(), status);
353 /* test for nullptr */
354 if (cal == 0) {
355 status = U_MEMORY_ALLOCATION_ERROR;
356 return;
357 }
358 if(U_FAILURE(status))
359 return;
360 cal->setTime(date, status);
361 fGregorianCutoverYear = cal->get(UCAL_YEAR, status);
362 if (cal->get(UCAL_ERA, status) == BC)
363 fGregorianCutoverYear = 1 - fGregorianCutoverYear;
364 fCutoverJulianDay = (int32_t)cutoverDay;
365 delete cal;
366 }
367
368
handleComputeFields(int32_t julianDay,UErrorCode & status)369 void GregorianCalendar::handleComputeFields(int32_t julianDay, UErrorCode& status) {
370 int32_t eyear, month, dayOfMonth, dayOfYear, unusedRemainder;
371
372
373 if(U_FAILURE(status)) {
374 return;
375 }
376
377 #if defined (U_DEBUG_CAL)
378 fprintf(stderr, "%s:%d: jd%d- (greg's %d)- [cut=%d]\n",
379 __FILE__, __LINE__, julianDay, getGregorianDayOfYear(), fCutoverJulianDay);
380 #endif
381
382
383 if (julianDay >= fCutoverJulianDay) {
384 month = getGregorianMonth();
385 dayOfMonth = getGregorianDayOfMonth();
386 dayOfYear = getGregorianDayOfYear();
387 eyear = getGregorianYear();
388 } else {
389 // The Julian epoch day (not the same as Julian Day)
390 // is zero on Saturday December 30, 0 (Gregorian).
391 int32_t julianEpochDay = julianDay - (kJan1_1JulianDay - 2);
392 eyear = (int32_t) ClockMath::floorDivide((4.0*julianEpochDay) + 1464.0, (int32_t) 1461, &unusedRemainder);
393
394 // Compute the Julian calendar day number for January 1, eyear
395 int32_t january1 = 365*(eyear-1) + ClockMath::floorDivide(eyear-1, (int32_t)4);
396 dayOfYear = (julianEpochDay - january1); // 0-based
397
398 // Julian leap years occurred historically every 4 years starting
399 // with 8 AD. Before 8 AD the spacing is irregular; every 3 years
400 // from 45 BC to 9 BC, and then none until 8 AD. However, we don't
401 // implement this historical detail; instead, we implement the
402 // computationally cleaner proleptic calendar, which assumes
403 // consistent 4-year cycles throughout time.
404 UBool isLeap = ((eyear&0x3) == 0); // equiv. to (eyear%4 == 0)
405
406 // Common Julian/Gregorian calculation
407 int32_t correction = 0;
408 int32_t march1 = isLeap ? 60 : 59; // zero-based DOY for March 1
409 if (dayOfYear >= march1) {
410 correction = isLeap ? 1 : 2;
411 }
412 month = (12 * (dayOfYear + correction) + 6) / 367; // zero-based month
413 dayOfMonth = dayOfYear - (isLeap?kLeapNumDays[month]:kNumDays[month]) + 1; // one-based DOM
414 ++dayOfYear;
415 #if defined (U_DEBUG_CAL)
416 // fprintf(stderr, "%d - %d[%d] + 1\n", dayOfYear, isLeap?kLeapNumDays[month]:kNumDays[month], month );
417 // fprintf(stderr, "%s:%d: greg's HCF %d -> %d/%d/%d not %d/%d/%d\n",
418 // __FILE__, __LINE__,julianDay,
419 // eyear,month,dayOfMonth,
420 // getGregorianYear(), getGregorianMonth(), getGregorianDayOfMonth() );
421 fprintf(stderr, "%s:%d: doy %d (greg's %d)- [cut=%d]\n",
422 __FILE__, __LINE__, dayOfYear, getGregorianDayOfYear(), fCutoverJulianDay);
423 #endif
424
425 }
426
427 // [j81] if we are after the cutover in its year, shift the day of the year
428 if((eyear == fGregorianCutoverYear) && (julianDay >= fCutoverJulianDay)) {
429 //from handleComputeMonthStart
430 int32_t gregShift = Grego::gregorianShift(eyear);
431 #if defined (U_DEBUG_CAL)
432 fprintf(stderr, "%s:%d: gregorian shift %d ::: doy%d => %d [cut=%d]\n",
433 __FILE__, __LINE__,gregShift, dayOfYear, dayOfYear+gregShift, fCutoverJulianDay);
434 #endif
435 dayOfYear += gregShift;
436 }
437
438 internalSet(UCAL_MONTH, month);
439 internalSet(UCAL_ORDINAL_MONTH, month);
440 internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
441 internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
442 internalSet(UCAL_EXTENDED_YEAR, eyear);
443 int32_t era = AD;
444 if (eyear < 1) {
445 era = BC;
446 eyear = 1 - eyear;
447 }
448 internalSet(UCAL_ERA, era);
449 internalSet(UCAL_YEAR, eyear);
450 }
451
452
453 // -------------------------------------
454
455 UDate
getGregorianChange() const456 GregorianCalendar::getGregorianChange() const
457 {
458 return fGregorianCutover;
459 }
460
461 // -------------------------------------
462
463 UBool
isLeapYear(int32_t year) const464 GregorianCalendar::isLeapYear(int32_t year) const
465 {
466 // MSVC complains bitterly if we try to use Grego::isLeapYear here
467 // NOTE: year&0x3 == year%4
468 return (year >= fGregorianCutoverYear ?
469 (((year&0x3) == 0) && ((year%100 != 0) || (year%400 == 0))) : // Gregorian
470 ((year&0x3) == 0)); // Julian
471 }
472
473 // -------------------------------------
474
handleComputeJulianDay(UCalendarDateFields bestField)475 int32_t GregorianCalendar::handleComputeJulianDay(UCalendarDateFields bestField)
476 {
477 fInvertGregorian = false;
478
479 int32_t jd = Calendar::handleComputeJulianDay(bestField);
480
481 if((bestField == UCAL_WEEK_OF_YEAR) && // if we are doing WOY calculations, we are counting relative to Jan 1 *julian*
482 (internalGet(UCAL_EXTENDED_YEAR)==fGregorianCutoverYear) &&
483 jd >= fCutoverJulianDay) {
484 fInvertGregorian = true; // So that the Julian Jan 1 will be used in handleComputeMonthStart
485 return Calendar::handleComputeJulianDay(bestField);
486 }
487
488
489 // The following check handles portions of the cutover year BEFORE the
490 // cutover itself happens.
491 //if ((fIsGregorian==true) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
492 if ((fIsGregorian) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
493 #if defined (U_DEBUG_CAL)
494 fprintf(stderr, "%s:%d: jd [invert] %d\n",
495 __FILE__, __LINE__, jd);
496 #endif
497 fInvertGregorian = true;
498 jd = Calendar::handleComputeJulianDay(bestField);
499 #if defined (U_DEBUG_CAL)
500 fprintf(stderr, "%s:%d: fIsGregorian %s, fInvertGregorian %s - ",
501 __FILE__, __LINE__,fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
502 fprintf(stderr, " jd NOW %d\n",
503 jd);
504 #endif
505 } else {
506 #if defined (U_DEBUG_CAL)
507 fprintf(stderr, "%s:%d: jd [==] %d - %sfIsGregorian %sfInvertGregorian, %d\n",
508 __FILE__, __LINE__, jd, fIsGregorian?"T":"F", fInvertGregorian?"T":"F", bestField);
509 #endif
510 }
511
512 if(fIsGregorian && (internalGet(UCAL_EXTENDED_YEAR) == fGregorianCutoverYear)) {
513 int32_t gregShift = Grego::gregorianShift(internalGet(UCAL_EXTENDED_YEAR));
514 if (bestField == UCAL_DAY_OF_YEAR) {
515 #if defined (U_DEBUG_CAL)
516 fprintf(stderr, "%s:%d: [DOY%d] gregorian shift of JD %d += %d\n",
517 __FILE__, __LINE__, fFields[bestField],jd, gregShift);
518 #endif
519 jd -= gregShift;
520 } else if ( bestField == UCAL_WEEK_OF_MONTH ) {
521 int32_t weekShift = 14;
522 #if defined (U_DEBUG_CAL)
523 fprintf(stderr, "%s:%d: [WOY/WOM] gregorian week shift of %d += %d\n",
524 __FILE__, __LINE__, jd, weekShift);
525 #endif
526 jd += weekShift; // shift by weeks for week based fields.
527 }
528 }
529
530 return jd;
531 }
532
handleComputeMonthStart(int32_t eyear,int32_t month,UBool) const533 int32_t GregorianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month,
534
535 UBool /* useMonth */) const
536 {
537 GregorianCalendar *nonConstThis = (GregorianCalendar*)this; // cast away const
538
539 // If the month is out of range, adjust it into range, and
540 // modify the extended year value accordingly.
541 if (month < 0 || month > 11) {
542 eyear += ClockMath::floorDivide(month, 12, &month);
543 }
544
545 UBool isLeap = eyear%4 == 0;
546 int64_t y = (int64_t)eyear-1;
547 int64_t julianDay = 365*y + ClockMath::floorDivide(y, (int64_t)4) + (kJan1_1JulianDay - 3);
548
549 nonConstThis->fIsGregorian = (eyear >= fGregorianCutoverYear);
550 #if defined (U_DEBUG_CAL)
551 fprintf(stderr, "%s:%d: (hcms%d/%d) fIsGregorian %s, fInvertGregorian %s\n",
552 __FILE__, __LINE__, eyear,month, fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
553 #endif
554 if (fInvertGregorian) {
555 nonConstThis->fIsGregorian = !fIsGregorian;
556 }
557 if (fIsGregorian) {
558 isLeap = isLeap && ((eyear%100 != 0) || (eyear%400 == 0));
559 // Add 2 because Gregorian calendar starts 2 days after
560 // Julian calendar
561 int32_t gregShift = Grego::gregorianShift(eyear);
562 #if defined (U_DEBUG_CAL)
563 fprintf(stderr, "%s:%d: (hcms%d/%d) gregorian shift of %d += %d\n",
564 __FILE__, __LINE__, eyear, month, julianDay, gregShift);
565 #endif
566 julianDay += gregShift;
567 }
568
569 // At this point julianDay indicates the day BEFORE the first
570 // day of January 1, <eyear> of either the Julian or Gregorian
571 // calendar.
572
573 if (month != 0) {
574 julianDay += isLeap?kLeapNumDays[month]:kNumDays[month];
575 }
576
577 return static_cast<int32_t>(julianDay);
578 }
579
handleGetMonthLength(int32_t extendedYear,int32_t month) const580 int32_t GregorianCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const
581 {
582 // If the month is out of range, adjust it into range, and
583 // modify the extended year value accordingly.
584 if (month < 0 || month > 11) {
585 extendedYear += ClockMath::floorDivide(month, 12, &month);
586 }
587
588 return isLeapYear(extendedYear) ? kLeapMonthLength[month] : kMonthLength[month];
589 }
590
handleGetYearLength(int32_t eyear) const591 int32_t GregorianCalendar::handleGetYearLength(int32_t eyear) const {
592 return isLeapYear(eyear) ? 366 : 365;
593 }
594
595
596 int32_t
monthLength(int32_t month) const597 GregorianCalendar::monthLength(int32_t month) const
598 {
599 int32_t year = internalGet(UCAL_EXTENDED_YEAR);
600 return handleGetMonthLength(year, month);
601 }
602
603 // -------------------------------------
604
605 int32_t
monthLength(int32_t month,int32_t year) const606 GregorianCalendar::monthLength(int32_t month, int32_t year) const
607 {
608 return isLeapYear(year) ? kLeapMonthLength[month] : kMonthLength[month];
609 }
610
611 // -------------------------------------
612
613 int32_t
yearLength(int32_t year) const614 GregorianCalendar::yearLength(int32_t year) const
615 {
616 return isLeapYear(year) ? 366 : 365;
617 }
618
619 // -------------------------------------
620
621 int32_t
yearLength() const622 GregorianCalendar::yearLength() const
623 {
624 return isLeapYear(internalGet(UCAL_YEAR)) ? 366 : 365;
625 }
626
627 // -------------------------------------
628
629 /**
630 * After adjustments such as add(MONTH), add(YEAR), we don't want the
631 * month to jump around. E.g., we don't want Jan 31 + 1 month to go to Mar
632 * 3, we want it to go to Feb 28. Adjustments which might run into this
633 * problem call this method to retain the proper month.
634 */
635 void
pinDayOfMonth()636 GregorianCalendar::pinDayOfMonth()
637 {
638 int32_t monthLen = monthLength(internalGetMonth());
639 int32_t dom = internalGet(UCAL_DATE);
640 if(dom > monthLen)
641 set(UCAL_DATE, monthLen);
642 }
643
644 // -------------------------------------
645
646
647 UBool
validateFields() const648 GregorianCalendar::validateFields() const
649 {
650 for (int32_t field = 0; field < UCAL_FIELD_COUNT; field++) {
651 // Ignore DATE and DAY_OF_YEAR which are handled below
652 if (field != UCAL_DATE &&
653 field != UCAL_DAY_OF_YEAR &&
654 isSet((UCalendarDateFields)field) &&
655 ! boundsCheck(internalGet((UCalendarDateFields)field), (UCalendarDateFields)field))
656 return false;
657 }
658
659 // Values differ in Least-Maximum and Maximum should be handled
660 // specially.
661 if (isSet(UCAL_DATE)) {
662 int32_t date = internalGet(UCAL_DATE);
663 if (date < getMinimum(UCAL_DATE) ||
664 date > monthLength(internalGetMonth())) {
665 return false;
666 }
667 }
668
669 if (isSet(UCAL_DAY_OF_YEAR)) {
670 int32_t days = internalGet(UCAL_DAY_OF_YEAR);
671 if (days < 1 || days > yearLength()) {
672 return false;
673 }
674 }
675
676 // Handle DAY_OF_WEEK_IN_MONTH, which must not have the value zero.
677 // We've checked against minimum and maximum above already.
678 if (isSet(UCAL_DAY_OF_WEEK_IN_MONTH) &&
679 0 == internalGet(UCAL_DAY_OF_WEEK_IN_MONTH)) {
680 return false;
681 }
682
683 return true;
684 }
685
686 // -------------------------------------
687
688 UBool
boundsCheck(int32_t value,UCalendarDateFields field) const689 GregorianCalendar::boundsCheck(int32_t value, UCalendarDateFields field) const
690 {
691 return value >= getMinimum(field) && value <= getMaximum(field);
692 }
693
694 // -------------------------------------
695
696 UDate
getEpochDay(UErrorCode & status)697 GregorianCalendar::getEpochDay(UErrorCode& status)
698 {
699 complete(status);
700 // Divide by 1000 (convert to seconds) in order to prevent overflow when
701 // dealing with UDate(Long.MIN_VALUE) and UDate(Long.MAX_VALUE).
702 double wallSec = internalGetTime()/1000 + (internalGet(UCAL_ZONE_OFFSET) + internalGet(UCAL_DST_OFFSET))/1000;
703
704 return ClockMath::floorDivide(wallSec, kOneDay/1000.0);
705 }
706
707 // -------------------------------------
708
709
710 // -------------------------------------
711
712 /**
713 * Compute the julian day number of the day BEFORE the first day of
714 * January 1, year 1 of the given calendar. If julianDay == 0, it
715 * specifies (Jan. 1, 1) - 1, in whatever calendar we are using (Julian
716 * or Gregorian).
717 */
computeJulianDayOfYear(UBool isGregorian,int32_t year,UBool & isLeap)718 double GregorianCalendar::computeJulianDayOfYear(UBool isGregorian,
719 int32_t year, UBool& isLeap)
720 {
721 isLeap = year%4 == 0;
722 int32_t y = year - 1;
723 double julianDay = 365.0*y + ClockMath::floorDivide(y, 4) + (kJan1_1JulianDay - 3);
724
725 if (isGregorian) {
726 isLeap = isLeap && ((year%100 != 0) || (year%400 == 0));
727 // Add 2 because Gregorian calendar starts 2 days after Julian calendar
728 julianDay += Grego::gregorianShift(year);
729 }
730
731 return julianDay;
732 }
733
734 // /**
735 // * Compute the day of week, relative to the first day of week, from
736 // * 0..6, of the current DOW_LOCAL or DAY_OF_WEEK fields. This is
737 // * equivalent to get(DOW_LOCAL) - 1.
738 // */
739 // int32_t GregorianCalendar::computeRelativeDOW() const {
740 // int32_t relDow = 0;
741 // if (fStamp[UCAL_DOW_LOCAL] > fStamp[UCAL_DAY_OF_WEEK]) {
742 // relDow = internalGet(UCAL_DOW_LOCAL) - 1; // 1-based
743 // } else if (fStamp[UCAL_DAY_OF_WEEK] != kUnset) {
744 // relDow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
745 // if (relDow < 0) relDow += 7;
746 // }
747 // return relDow;
748 // }
749
750 // /**
751 // * Compute the day of week, relative to the first day of week,
752 // * from 0..6 of the given julian day.
753 // */
754 // int32_t GregorianCalendar::computeRelativeDOW(double julianDay) const {
755 // int32_t relDow = julianDayToDayOfWeek(julianDay) - getFirstDayOfWeek();
756 // if (relDow < 0) {
757 // relDow += 7;
758 // }
759 // return relDow;
760 // }
761
762 // /**
763 // * Compute the DOY using the WEEK_OF_YEAR field and the julian day
764 // * of the day BEFORE January 1 of a year (a return value from
765 // * computeJulianDayOfYear).
766 // */
767 // int32_t GregorianCalendar::computeDOYfromWOY(double julianDayOfYear) const {
768 // // Compute DOY from day of week plus week of year
769
770 // // Find the day of the week for the first of this year. This
771 // // is zero-based, with 0 being the locale-specific first day of
772 // // the week. Add 1 to get first day of year.
773 // int32_t fdy = computeRelativeDOW(julianDayOfYear + 1);
774
775 // return
776 // // Compute doy of first (relative) DOW of WOY 1
777 // (((7 - fdy) < getMinimalDaysInFirstWeek())
778 // ? (8 - fdy) : (1 - fdy))
779
780 // // Adjust for the week number.
781 // + (7 * (internalGet(UCAL_WEEK_OF_YEAR) - 1))
782
783 // // Adjust for the DOW
784 // + computeRelativeDOW();
785 // }
786
787 // -------------------------------------
788
789 double
millisToJulianDay(UDate millis)790 GregorianCalendar::millisToJulianDay(UDate millis)
791 {
792 return (double)kEpochStartAsJulianDay + ClockMath::floorDivide(millis, (double)kOneDay);
793 }
794
795 // -------------------------------------
796
797 UDate
julianDayToMillis(double julian)798 GregorianCalendar::julianDayToMillis(double julian)
799 {
800 return (UDate) ((julian - kEpochStartAsJulianDay) * (double) kOneDay);
801 }
802
803 // -------------------------------------
804
805 int32_t
aggregateStamp(int32_t stamp_a,int32_t stamp_b)806 GregorianCalendar::aggregateStamp(int32_t stamp_a, int32_t stamp_b)
807 {
808 return (((stamp_a != kUnset && stamp_b != kUnset)
809 ? uprv_max(stamp_a, stamp_b)
810 : (int32_t)kUnset));
811 }
812
813 // -------------------------------------
814
815 /**
816 * Roll a field by a signed amount.
817 * Note: This will be made public later. [LIU]
818 */
819
820 void
roll(EDateFields field,int32_t amount,UErrorCode & status)821 GregorianCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) {
822 roll((UCalendarDateFields) field, amount, status);
823 }
824
825 void
roll(UCalendarDateFields field,int32_t amount,UErrorCode & status)826 GregorianCalendar::roll(UCalendarDateFields field, int32_t amount, UErrorCode& status) UPRV_NO_SANITIZE_UNDEFINED {
827 if((amount == 0) || U_FAILURE(status)) {
828 return;
829 }
830
831 // J81 processing. (gregorian cutover)
832 UBool inCutoverMonth = false;
833 int32_t cMonthLen=0; // 'c' for cutover; in days
834 int32_t cDayOfMonth=0; // no discontinuity: [0, cMonthLen)
835 double cMonthStart=0.0; // in ms
836
837 // Common code - see if we're in the cutover month of the cutover year
838 if(get(UCAL_EXTENDED_YEAR, status) == fGregorianCutoverYear) {
839 switch (field) {
840 case UCAL_DAY_OF_MONTH:
841 case UCAL_WEEK_OF_MONTH:
842 {
843 int32_t max = monthLength(internalGetMonth());
844 UDate t = internalGetTime();
845 // We subtract 1 from the DAY_OF_MONTH to make it zero-based, and an
846 // additional 10 if we are after the cutover. Thus the monthStart
847 // value will be correct iff we actually are in the cutover month.
848 cDayOfMonth = internalGet(UCAL_DAY_OF_MONTH) - ((t >= fGregorianCutover) ? 10 : 0);
849 cMonthStart = t - ((cDayOfMonth - 1) * kOneDay);
850 // A month containing the cutover is 10 days shorter.
851 if ((cMonthStart < fGregorianCutover) &&
852 (cMonthStart + (cMonthLen=(max-10))*kOneDay >= fGregorianCutover)) {
853 inCutoverMonth = true;
854 }
855 }
856 break;
857 default:
858 ;
859 }
860 }
861
862 switch (field) {
863 case UCAL_WEEK_OF_YEAR: {
864 // Unlike WEEK_OF_MONTH, WEEK_OF_YEAR never shifts the day of the
865 // week. Also, rolling the week of the year can have seemingly
866 // strange effects simply because the year of the week of year
867 // may be different from the calendar year. For example, the
868 // date Dec 28, 1997 is the first day of week 1 of 1998 (if
869 // weeks start on Sunday and the minimal days in first week is
870 // <= 3).
871 int32_t woy = get(UCAL_WEEK_OF_YEAR, status);
872 // Get the ISO year, which matches the week of year. This
873 // may be one year before or after the calendar year.
874 int32_t isoYear = get(UCAL_YEAR_WOY, status);
875 int32_t isoDoy = internalGet(UCAL_DAY_OF_YEAR);
876 if (internalGetMonth() == UCAL_JANUARY) {
877 if (woy >= 52) {
878 isoDoy += handleGetYearLength(isoYear);
879 }
880 } else {
881 if (woy == 1) {
882 isoDoy -= handleGetYearLength(isoYear - 1);
883 }
884 }
885 woy += amount;
886 // Do fast checks to avoid unnecessary computation:
887 if (woy < 1 || woy > 52) {
888 // Determine the last week of the ISO year.
889 // We do this using the standard formula we use
890 // everywhere in this file. If we can see that the
891 // days at the end of the year are going to fall into
892 // week 1 of the next year, we drop the last week by
893 // subtracting 7 from the last day of the year.
894 int32_t lastDoy = handleGetYearLength(isoYear);
895 int32_t lastRelDow = (lastDoy - isoDoy + internalGet(UCAL_DAY_OF_WEEK) -
896 getFirstDayOfWeek()) % 7;
897 if (lastRelDow < 0) lastRelDow += 7;
898 if ((6 - lastRelDow) >= getMinimalDaysInFirstWeek()) lastDoy -= 7;
899 int32_t lastWoy = weekNumber(lastDoy, lastRelDow + 1);
900 woy = ((woy + lastWoy - 1) % lastWoy) + 1;
901 }
902 set(UCAL_WEEK_OF_YEAR, woy);
903 set(UCAL_YEAR_WOY,isoYear);
904 return;
905 }
906
907 case UCAL_DAY_OF_MONTH:
908 if( !inCutoverMonth ) {
909 Calendar::roll(field, amount, status);
910 return;
911 } else {
912 // [j81] 1582 special case for DOM
913 // The default computation works except when the current month
914 // contains the Gregorian cutover. We handle this special case
915 // here. [j81 - aliu]
916 double monthLen = cMonthLen * kOneDay;
917 double msIntoMonth = uprv_fmod(internalGetTime() - cMonthStart +
918 amount * kOneDay, monthLen);
919 if (msIntoMonth < 0) {
920 msIntoMonth += monthLen;
921 }
922 #if defined (U_DEBUG_CAL)
923 fprintf(stderr, "%s:%d: roll DOM %d -> %.0lf ms \n",
924 __FILE__, __LINE__,amount, cMonthLen, cMonthStart+msIntoMonth);
925 #endif
926 setTimeInMillis(cMonthStart + msIntoMonth, status);
927 return;
928 }
929
930 case UCAL_WEEK_OF_MONTH:
931 if( !inCutoverMonth ) {
932 Calendar::roll(field, amount, status);
933 return;
934 } else {
935 #if defined (U_DEBUG_CAL)
936 fprintf(stderr, "%s:%d: roll WOM %d ??????????????????? \n",
937 __FILE__, __LINE__,amount);
938 #endif
939 // NOTE: following copied from the old
940 // GregorianCalendar::roll( WEEK_OF_MONTH ) code
941
942 // This is tricky, because during the roll we may have to shift
943 // to a different day of the week. For example:
944
945 // s m t w r f s
946 // 1 2 3 4 5
947 // 6 7 8 9 10 11 12
948
949 // When rolling from the 6th or 7th back one week, we go to the
950 // 1st (assuming that the first partial week counts). The same
951 // thing happens at the end of the month.
952
953 // The other tricky thing is that we have to figure out whether
954 // the first partial week actually counts or not, based on the
955 // minimal first days in the week. And we have to use the
956 // correct first day of the week to delineate the week
957 // boundaries.
958
959 // Here's our algorithm. First, we find the real boundaries of
960 // the month. Then we discard the first partial week if it
961 // doesn't count in this locale. Then we fill in the ends with
962 // phantom days, so that the first partial week and the last
963 // partial week are full weeks. We then have a nice square
964 // block of weeks. We do the usual rolling within this block,
965 // as is done elsewhere in this method. If we wind up on one of
966 // the phantom days that we added, we recognize this and pin to
967 // the first or the last day of the month. Easy, eh?
968
969 // Another wrinkle: To fix jitterbug 81, we have to make all this
970 // work in the oddball month containing the Gregorian cutover.
971 // This month is 10 days shorter than usual, and also contains
972 // a discontinuity in the days; e.g., the default cutover month
973 // is Oct 1582, and goes from day of month 4 to day of month 15.
974
975 // Normalize the DAY_OF_WEEK so that 0 is the first day of the week
976 // in this locale. We have dow in 0..6.
977 int32_t dow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
978 if (dow < 0)
979 dow += 7;
980
981 // Find the day of month, compensating for cutover discontinuity.
982 int32_t dom = cDayOfMonth;
983
984 // Find the day of the week (normalized for locale) for the first
985 // of the month.
986 int32_t fdm = (dow - dom + 1) % 7;
987 if (fdm < 0)
988 fdm += 7;
989
990 // Get the first day of the first full week of the month,
991 // including phantom days, if any. Figure out if the first week
992 // counts or not; if it counts, then fill in phantom days. If
993 // not, advance to the first real full week (skip the partial week).
994 int32_t start;
995 if ((7 - fdm) < getMinimalDaysInFirstWeek())
996 start = 8 - fdm; // Skip the first partial week
997 else
998 start = 1 - fdm; // This may be zero or negative
999
1000 // Get the day of the week (normalized for locale) for the last
1001 // day of the month.
1002 int32_t monthLen = cMonthLen;
1003 int32_t ldm = (monthLen - dom + dow) % 7;
1004 // We know monthLen >= DAY_OF_MONTH so we skip the += 7 step here.
1005
1006 // Get the limit day for the blocked-off rectangular month; that
1007 // is, the day which is one past the last day of the month,
1008 // after the month has already been filled in with phantom days
1009 // to fill out the last week. This day has a normalized DOW of 0.
1010 int32_t limit = monthLen + 7 - ldm;
1011
1012 // Now roll between start and (limit - 1).
1013 int32_t gap = limit - start;
1014 int32_t newDom = (dom + amount*7 - start) % gap;
1015 if (newDom < 0)
1016 newDom += gap;
1017 newDom += start;
1018
1019 // Finally, pin to the real start and end of the month.
1020 if (newDom < 1)
1021 newDom = 1;
1022 if (newDom > monthLen)
1023 newDom = monthLen;
1024
1025 // Set the DAY_OF_MONTH. We rely on the fact that this field
1026 // takes precedence over everything else (since all other fields
1027 // are also set at this point). If this fact changes (if the
1028 // disambiguation algorithm changes) then we will have to unset
1029 // the appropriate fields here so that DAY_OF_MONTH is attended
1030 // to.
1031
1032 // If we are in the cutover month, manipulate ms directly. Don't do
1033 // this in general because it doesn't work across DST boundaries
1034 // (details, details). This takes care of the discontinuity.
1035 setTimeInMillis(cMonthStart + (newDom-1)*kOneDay, status);
1036 return;
1037 }
1038
1039 default:
1040 Calendar::roll(field, amount, status);
1041 return;
1042 }
1043 }
1044
1045 // -------------------------------------
1046
1047
1048 /**
1049 * Return the minimum value that this field could have, given the current date.
1050 * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1051 * @param field the time field.
1052 * @return the minimum value that this field could have, given the current date.
1053 * @deprecated ICU 2.6. Use getActualMinimum(UCalendarDateFields field) instead.
1054 */
getActualMinimum(EDateFields field) const1055 int32_t GregorianCalendar::getActualMinimum(EDateFields field) const
1056 {
1057 return getMinimum((UCalendarDateFields)field);
1058 }
1059
getActualMinimum(EDateFields field,UErrorCode &) const1060 int32_t GregorianCalendar::getActualMinimum(EDateFields field, UErrorCode& /* status */) const
1061 {
1062 return getMinimum((UCalendarDateFields)field);
1063 }
1064
1065 /**
1066 * Return the minimum value that this field could have, given the current date.
1067 * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1068 * @param field the time field.
1069 * @return the minimum value that this field could have, given the current date.
1070 * @draft ICU 2.6.
1071 */
getActualMinimum(UCalendarDateFields field,UErrorCode &) const1072 int32_t GregorianCalendar::getActualMinimum(UCalendarDateFields field, UErrorCode& /* status */) const
1073 {
1074 return getMinimum(field);
1075 }
1076
1077
1078 // ------------------------------------
1079
1080 /**
1081 * Old year limits were least max 292269054, max 292278994.
1082 */
1083
1084 /**
1085 * @stable ICU 2.0
1086 */
handleGetLimit(UCalendarDateFields field,ELimitType limitType) const1087 int32_t GregorianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
1088 return kGregorianCalendarLimits[field][limitType];
1089 }
1090
1091 /**
1092 * Return the maximum value that this field could have, given the current date.
1093 * For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual
1094 * maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar,
1095 * for some years the actual maximum for MONTH is 12, and for others 13.
1096 * @stable ICU 2.0
1097 */
getActualMaximum(UCalendarDateFields field,UErrorCode & status) const1098 int32_t GregorianCalendar::getActualMaximum(UCalendarDateFields field, UErrorCode& status) const
1099 {
1100 /* It is a known limitation that the code here (and in getActualMinimum)
1101 * won't behave properly at the extreme limits of GregorianCalendar's
1102 * representable range (except for the code that handles the YEAR
1103 * field). That's because the ends of the representable range are at
1104 * odd spots in the year. For calendars with the default Gregorian
1105 * cutover, these limits are Sun Dec 02 16:47:04 GMT 292269055 BC to Sun
1106 * Aug 17 07:12:55 GMT 292278994 AD, somewhat different for non-GMT
1107 * zones. As a result, if the calendar is set to Aug 1 292278994 AD,
1108 * the actual maximum of DAY_OF_MONTH is 17, not 30. If the date is Mar
1109 * 31 in that year, the actual maximum month might be Jul, whereas is
1110 * the date is Mar 15, the actual maximum might be Aug -- depending on
1111 * the precise semantics that are desired. Similar considerations
1112 * affect all fields. Nonetheless, this effect is sufficiently arcane
1113 * that we permit it, rather than complicating the code to handle such
1114 * intricacies. - liu 8/20/98
1115
1116 * UPDATE: No longer true, since we have pulled in the limit values on
1117 * the year. - Liu 11/6/00 */
1118
1119 switch (field) {
1120
1121 case UCAL_YEAR:
1122 /* The year computation is no different, in principle, from the
1123 * others, however, the range of possible maxima is large. In
1124 * addition, the way we know we've exceeded the range is different.
1125 * For these reasons, we use the special case code below to handle
1126 * this field.
1127 *
1128 * The actual maxima for YEAR depend on the type of calendar:
1129 *
1130 * Gregorian = May 17, 292275056 BC - Aug 17, 292278994 AD
1131 * Julian = Dec 2, 292269055 BC - Jan 3, 292272993 AD
1132 * Hybrid = Dec 2, 292269055 BC - Aug 17, 292278994 AD
1133 *
1134 * We know we've exceeded the maximum when either the month, date,
1135 * time, or era changes in response to setting the year. We don't
1136 * check for month, date, and time here because the year and era are
1137 * sufficient to detect an invalid year setting. NOTE: If code is
1138 * added to check the month and date in the future for some reason,
1139 * Feb 29 must be allowed to shift to Mar 1 when setting the year.
1140 */
1141 {
1142 if(U_FAILURE(status)) return 0;
1143 Calendar *cal = clone();
1144 if(!cal) {
1145 status = U_MEMORY_ALLOCATION_ERROR;
1146 return 0;
1147 }
1148
1149 cal->setLenient(true);
1150
1151 int32_t era = cal->get(UCAL_ERA, status);
1152 UDate d = cal->getTime(status);
1153
1154 /* Perform a binary search, with the invariant that lowGood is a
1155 * valid year, and highBad is an out of range year.
1156 */
1157 int32_t lowGood = kGregorianCalendarLimits[UCAL_YEAR][1];
1158 int32_t highBad = kGregorianCalendarLimits[UCAL_YEAR][2]+1;
1159 while ((lowGood + 1) < highBad) {
1160 int32_t y = (lowGood + highBad) / 2;
1161 cal->set(UCAL_YEAR, y);
1162 if (cal->get(UCAL_YEAR, status) == y && cal->get(UCAL_ERA, status) == era) {
1163 lowGood = y;
1164 } else {
1165 highBad = y;
1166 cal->setTime(d, status); // Restore original fields
1167 }
1168 }
1169
1170 delete cal;
1171 return lowGood;
1172 }
1173
1174 default:
1175 return Calendar::getActualMaximum(field,status);
1176 }
1177 }
1178
1179
handleGetExtendedYear()1180 int32_t GregorianCalendar::handleGetExtendedYear() {
1181 // the year to return
1182 int32_t year = kEpochYear;
1183
1184 // year field to use
1185 int32_t yearField = UCAL_EXTENDED_YEAR;
1186
1187 // There are three separate fields which could be used to
1188 // derive the proper year. Use the one most recently set.
1189 if (fStamp[yearField] < fStamp[UCAL_YEAR])
1190 yearField = UCAL_YEAR;
1191 if (fStamp[yearField] < fStamp[UCAL_YEAR_WOY])
1192 yearField = UCAL_YEAR_WOY;
1193
1194 // based on the "best" year field, get the year
1195 switch(yearField) {
1196 case UCAL_EXTENDED_YEAR:
1197 year = internalGet(UCAL_EXTENDED_YEAR, kEpochYear);
1198 break;
1199
1200 case UCAL_YEAR:
1201 {
1202 // The year defaults to the epoch start, the era to AD
1203 int32_t era = internalGet(UCAL_ERA, AD);
1204 if (era == BC) {
1205 year = 1 - internalGet(UCAL_YEAR, 1); // Convert to extended year
1206 } else {
1207 year = internalGet(UCAL_YEAR, kEpochYear);
1208 }
1209 }
1210 break;
1211
1212 case UCAL_YEAR_WOY:
1213 year = handleGetExtendedYearFromWeekFields(internalGet(UCAL_YEAR_WOY), internalGet(UCAL_WEEK_OF_YEAR));
1214 #if defined (U_DEBUG_CAL)
1215 // if(internalGet(UCAL_YEAR_WOY) != year) {
1216 fprintf(stderr, "%s:%d: hGEYFWF[%d,%d] -> %d\n",
1217 __FILE__, __LINE__,internalGet(UCAL_YEAR_WOY),internalGet(UCAL_WEEK_OF_YEAR),year);
1218 //}
1219 #endif
1220 break;
1221
1222 default:
1223 year = kEpochYear;
1224 }
1225 return year;
1226 }
1227
handleGetExtendedYearFromWeekFields(int32_t yearWoy,int32_t woy)1228 int32_t GregorianCalendar::handleGetExtendedYearFromWeekFields(int32_t yearWoy, int32_t woy)
1229 {
1230 // convert year to extended form
1231 int32_t era = internalGet(UCAL_ERA, AD);
1232 if(era == BC) {
1233 yearWoy = 1 - yearWoy;
1234 }
1235 return Calendar::handleGetExtendedYearFromWeekFields(yearWoy, woy);
1236 }
1237
1238
1239 // -------------------------------------
1240
1241 /**
1242 * Return the ERA. We need a special method for this because the
1243 * default ERA is AD, but a zero (unset) ERA is BC.
1244 */
1245 int32_t
internalGetEra() const1246 GregorianCalendar::internalGetEra() const {
1247 return isSet(UCAL_ERA) ? internalGet(UCAL_ERA) : (int32_t)AD;
1248 }
1249
1250 const char *
getType() const1251 GregorianCalendar::getType() const {
1252 //static const char kGregorianType = "gregorian";
1253
1254 return "gregorian";
1255 }
1256
1257 /**
1258 * The system maintains a static default century start date and Year. They are
1259 * initialized the first time they are used. Once the system default century date
1260 * and year are set, they do not change.
1261 */
1262 static UDate gSystemDefaultCenturyStart = DBL_MIN;
1263 static int32_t gSystemDefaultCenturyStartYear = -1;
1264 static icu::UInitOnce gSystemDefaultCenturyInit {};
1265
1266
haveDefaultCentury() const1267 UBool GregorianCalendar::haveDefaultCentury() const
1268 {
1269 return true;
1270 }
1271
1272 static void U_CALLCONV
initializeSystemDefaultCentury()1273 initializeSystemDefaultCentury()
1274 {
1275 // initialize systemDefaultCentury and systemDefaultCenturyYear based
1276 // on the current time. They'll be set to 80 years before
1277 // the current time.
1278 UErrorCode status = U_ZERO_ERROR;
1279 GregorianCalendar calendar(status);
1280 if (U_SUCCESS(status)) {
1281 calendar.setTime(Calendar::getNow(), status);
1282 calendar.add(UCAL_YEAR, -80, status);
1283
1284 gSystemDefaultCenturyStart = calendar.getTime(status);
1285 gSystemDefaultCenturyStartYear = calendar.get(UCAL_YEAR, status);
1286 }
1287 // We have no recourse upon failure unless we want to propagate the failure
1288 // out.
1289 }
1290
defaultCenturyStart() const1291 UDate GregorianCalendar::defaultCenturyStart() const {
1292 // lazy-evaluate systemDefaultCenturyStart
1293 umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
1294 return gSystemDefaultCenturyStart;
1295 }
1296
defaultCenturyStartYear() const1297 int32_t GregorianCalendar::defaultCenturyStartYear() const {
1298 // lazy-evaluate systemDefaultCenturyStartYear
1299 umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
1300 return gSystemDefaultCenturyStartYear;
1301 }
1302
1303 U_NAMESPACE_END
1304
1305 #endif /* #if !UCONFIG_NO_FORMATTING */
1306
1307 //eof
1308