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, 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 == nullptr) {
355 status = U_MEMORY_ALLOCATION_ERROR;
356 return;
357 }
358 if(U_FAILURE(status)) {
359 return;
360 }
361 cal->setTime(date, status);
362 fGregorianCutoverYear = cal->get(UCAL_YEAR, status);
363 if (cal->get(UCAL_ERA, status) == BC) {
364 fGregorianCutoverYear = 1 - fGregorianCutoverYear;
365 }
366 fCutoverJulianDay = static_cast<int32_t>(cutoverDay);
367 delete cal;
368 }
369
handleComputeFields(int32_t julianDay,UErrorCode & status)370 void GregorianCalendar::handleComputeFields(int32_t julianDay, UErrorCode& status) {
371 int32_t eyear, month, dayOfMonth, dayOfYear, unusedRemainder;
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 if (julianDay >= fCutoverJulianDay) {
383 month = getGregorianMonth();
384 dayOfMonth = getGregorianDayOfMonth();
385 dayOfYear = getGregorianDayOfYear();
386 eyear = getGregorianYear();
387 } else {
388 // The Julian epoch day (not the same as Julian Day)
389 // is zero on Saturday December 30, 0 (Gregorian).
390 int32_t julianEpochDay = julianDay - (kJan1_1JulianDay - 2);
391 eyear = static_cast<int32_t>(ClockMath::floorDivide((4.0 * julianEpochDay) + 1464.0, static_cast<int32_t>(1461), &unusedRemainder));
392
393 // Compute the Julian calendar day number for January 1, eyear
394 int32_t january1 = 365 * (eyear - 1) + ClockMath::floorDivide(eyear - 1, static_cast<int32_t>(4));
395 dayOfYear = (julianEpochDay - january1); // 0-based
396
397 // Julian leap years occurred historically every 4 years starting
398 // with 8 AD. Before 8 AD the spacing is irregular; every 3 years
399 // from 45 BC to 9 BC, and then none until 8 AD. However, we don't
400 // implement this historical detail; instead, we implement the
401 // computationally cleaner proleptic calendar, which assumes
402 // consistent 4-year cycles throughout time.
403 UBool isLeap = ((eyear&0x3) == 0); // equiv. to (eyear%4 == 0)
404
405 // Common Julian/Gregorian calculation
406 int32_t correction = 0;
407 int32_t march1 = isLeap ? 60 : 59; // zero-based DOY for March 1
408 if (dayOfYear >= march1) {
409 correction = isLeap ? 1 : 2;
410 }
411 month = (12 * (dayOfYear + correction) + 6) / 367; // zero-based month
412 dayOfMonth = dayOfYear - (isLeap?kLeapNumDays[month]:kNumDays[month]) + 1; // one-based DOM
413 ++dayOfYear;
414 #if defined (U_DEBUG_CAL)
415 // fprintf(stderr, "%d - %d[%d] + 1\n", dayOfYear, isLeap?kLeapNumDays[month]:kNumDays[month], month );
416 // fprintf(stderr, "%s:%d: greg's HCF %d -> %d/%d/%d not %d/%d/%d\n",
417 // __FILE__, __LINE__,julianDay,
418 // eyear,month,dayOfMonth,
419 // getGregorianYear(), getGregorianMonth(), getGregorianDayOfMonth() );
420 fprintf(stderr, "%s:%d: doy %d (greg's %d)- [cut=%d]\n",
421 __FILE__, __LINE__, dayOfYear, getGregorianDayOfYear(), fCutoverJulianDay);
422 #endif
423
424 }
425
426 // [j81] if we are after the cutover in its year, shift the day of the year
427 if((eyear == fGregorianCutoverYear) && (julianDay >= fCutoverJulianDay)) {
428 //from handleComputeMonthStart
429 int32_t gregShift = Grego::gregorianShift(eyear);
430 #if defined (U_DEBUG_CAL)
431 fprintf(stderr, "%s:%d: gregorian shift %d ::: doy%d => %d [cut=%d]\n",
432 __FILE__, __LINE__,gregShift, dayOfYear, dayOfYear+gregShift, fCutoverJulianDay);
433 #endif
434 dayOfYear += gregShift;
435 }
436
437 internalSet(UCAL_MONTH, month);
438 internalSet(UCAL_ORDINAL_MONTH, month);
439 internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
440 internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
441 internalSet(UCAL_EXTENDED_YEAR, eyear);
442 int32_t era = AD;
443 if (eyear < 1) {
444 era = BC;
445 eyear = 1 - eyear;
446 }
447 internalSet(UCAL_ERA, era);
448 internalSet(UCAL_YEAR, eyear);
449 }
450
451
452 // -------------------------------------
453
454 UDate
getGregorianChange() const455 GregorianCalendar::getGregorianChange() const
456 {
457 return fGregorianCutover;
458 }
459
460 // -------------------------------------
461
462 UBool
isLeapYear(int32_t year) const463 GregorianCalendar::isLeapYear(int32_t year) const
464 {
465 // MSVC complains bitterly if we try to use Grego::isLeapYear here
466 // NOTE: year&0x3 == year%4
467 return (year >= fGregorianCutoverYear ?
468 (((year&0x3) == 0) && ((year%100 != 0) || (year%400 == 0))) : // Gregorian
469 ((year&0x3) == 0)); // Julian
470 }
471
472 // -------------------------------------
473
handleComputeJulianDay(UCalendarDateFields bestField,UErrorCode & status)474 int32_t GregorianCalendar::handleComputeJulianDay(UCalendarDateFields bestField, UErrorCode& status)
475 {
476 fInvertGregorian = false;
477
478 int32_t jd = Calendar::handleComputeJulianDay(bestField, status);
479 if (U_FAILURE(status)) {
480 return 0;
481 }
482
483 if((bestField == UCAL_WEEK_OF_YEAR) && // if we are doing WOY calculations, we are counting relative to Jan 1 *julian*
484 (internalGet(UCAL_EXTENDED_YEAR)==fGregorianCutoverYear) &&
485 jd >= fCutoverJulianDay) {
486 fInvertGregorian = true; // So that the Julian Jan 1 will be used in handleComputeMonthStart
487 return Calendar::handleComputeJulianDay(bestField, status);
488 }
489
490
491 // The following check handles portions of the cutover year BEFORE the
492 // cutover itself happens.
493 //if ((fIsGregorian==true) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
494 if ((fIsGregorian) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
495 #if defined (U_DEBUG_CAL)
496 fprintf(stderr, "%s:%d: jd [invert] %d\n",
497 __FILE__, __LINE__, jd);
498 #endif
499 fInvertGregorian = true;
500 jd = Calendar::handleComputeJulianDay(bestField, status);
501 if (U_FAILURE(status)) {
502 return 0;
503 }
504 #if defined (U_DEBUG_CAL)
505 fprintf(stderr, "%s:%d: fIsGregorian %s, fInvertGregorian %s - ",
506 __FILE__, __LINE__,fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
507 fprintf(stderr, " jd NOW %d\n",
508 jd);
509 #endif
510 } else {
511 #if defined (U_DEBUG_CAL)
512 fprintf(stderr, "%s:%d: jd [==] %d - %sfIsGregorian %sfInvertGregorian, %d\n",
513 __FILE__, __LINE__, jd, fIsGregorian?"T":"F", fInvertGregorian?"T":"F", bestField);
514 #endif
515 }
516
517 if(fIsGregorian && (internalGet(UCAL_EXTENDED_YEAR) == fGregorianCutoverYear)) {
518 int32_t gregShift = Grego::gregorianShift(internalGet(UCAL_EXTENDED_YEAR));
519 if (bestField == UCAL_DAY_OF_YEAR) {
520 #if defined (U_DEBUG_CAL)
521 fprintf(stderr, "%s:%d: [DOY%d] gregorian shift of JD %d += %d\n",
522 __FILE__, __LINE__, fFields[bestField],jd, gregShift);
523 #endif
524 jd -= gregShift;
525 } else if ( bestField == UCAL_WEEK_OF_MONTH ) {
526 int32_t weekShift = 14;
527 #if defined (U_DEBUG_CAL)
528 fprintf(stderr, "%s:%d: [WOY/WOM] gregorian week shift of %d += %d\n",
529 __FILE__, __LINE__, jd, weekShift);
530 #endif
531 jd += weekShift; // shift by weeks for week based fields.
532 }
533 }
534
535 return jd;
536 }
537
handleComputeMonthStart(int32_t eyear,int32_t month,UBool,UErrorCode & status) const538 int64_t GregorianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month,
539
540 UBool /* useMonth */, UErrorCode& status) const
541 {
542 if (U_FAILURE(status)) {
543 return 0;
544 }
545 GregorianCalendar* nonConstThis = const_cast<GregorianCalendar*>(this); // cast away const
546
547 // If the month is out of range, adjust it into range, and
548 // modify the extended year value accordingly.
549 if (month < 0 || month > 11) {
550 if (uprv_add32_overflow(ClockMath::floorDivide(month, 12, &month),
551 eyear, &eyear)) {
552 status = U_ILLEGAL_ARGUMENT_ERROR;
553 return 0;
554 }
555 }
556
557 UBool isLeap = eyear%4 == 0;
558 int64_t y = static_cast<int64_t>(eyear) - 1;
559 int64_t julianDay = 365LL * y +
560 ClockMath::floorDivideInt64(y, 4LL) + kJan1_1JulianDay - 3LL;
561
562 nonConstThis->fIsGregorian = (eyear >= fGregorianCutoverYear);
563 #if defined (U_DEBUG_CAL)
564 fprintf(stderr, "%s:%d: (hcms%d/%d) fIsGregorian %s, fInvertGregorian %s\n",
565 __FILE__, __LINE__, eyear,month, fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
566 #endif
567 if (fInvertGregorian) {
568 nonConstThis->fIsGregorian = !fIsGregorian;
569 }
570 if (fIsGregorian) {
571 isLeap = isLeap && ((eyear%100 != 0) || (eyear%400 == 0));
572 // Add 2 because Gregorian calendar starts 2 days after
573 // Julian calendar
574 int32_t gregShift = Grego::gregorianShift(eyear);
575 #if defined (U_DEBUG_CAL)
576 fprintf(stderr, "%s:%d: (hcms%d/%d) gregorian shift of %d += %d\n",
577 __FILE__, __LINE__, eyear, month, julianDay, gregShift);
578 #endif
579 julianDay += gregShift;
580 }
581
582 // At this point julianDay indicates the day BEFORE the first
583 // day of January 1, <eyear> of either the Julian or Gregorian
584 // calendar.
585
586 if (month != 0) {
587 julianDay += isLeap?kLeapNumDays[month]:kNumDays[month];
588 }
589
590 return julianDay;
591 }
592
handleGetMonthLength(int32_t extendedYear,int32_t month,UErrorCode &) const593 int32_t GregorianCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month, UErrorCode& /* status */) const
594 {
595 // If the month is out of range, adjust it into range, and
596 // modify the extended year value accordingly.
597 if (month < 0 || month > 11) {
598 extendedYear += ClockMath::floorDivide(month, 12, &month);
599 }
600
601 return isLeapYear(extendedYear) ? kLeapMonthLength[month] : kMonthLength[month];
602 }
603
handleGetYearLength(int32_t eyear) const604 int32_t GregorianCalendar::handleGetYearLength(int32_t eyear) const {
605 return isLeapYear(eyear) ? 366 : 365;
606 }
607
608
609 int32_t
monthLength(int32_t month,UErrorCode & status) const610 GregorianCalendar::monthLength(int32_t month, UErrorCode& status) const
611 {
612 int32_t year = internalGet(UCAL_EXTENDED_YEAR);
613 return handleGetMonthLength(year, month, status);
614 }
615
616 // -------------------------------------
617
618 int32_t
monthLength(int32_t month,int32_t year) const619 GregorianCalendar::monthLength(int32_t month, int32_t year) const
620 {
621 return isLeapYear(year) ? kLeapMonthLength[month] : kMonthLength[month];
622 }
623
624 // -------------------------------------
625
626 int32_t
yearLength() const627 GregorianCalendar::yearLength() const
628 {
629 return isLeapYear(internalGet(UCAL_YEAR)) ? 366 : 365;
630 }
631
632 // -------------------------------------
633
634 UBool
validateFields() const635 GregorianCalendar::validateFields() const
636 {
637 for (int32_t field = 0; field < UCAL_FIELD_COUNT; field++) {
638 // Ignore DATE and DAY_OF_YEAR which are handled below
639 if (field != UCAL_DATE &&
640 field != UCAL_DAY_OF_YEAR &&
641 isSet(static_cast<UCalendarDateFields>(field)) &&
642 !boundsCheck(internalGet(static_cast<UCalendarDateFields>(field)), static_cast<UCalendarDateFields>(field)))
643 return false;
644 }
645
646 // Values differ in Least-Maximum and Maximum should be handled
647 // specially.
648 if (isSet(UCAL_DATE)) {
649 int32_t date = internalGet(UCAL_DATE);
650 UErrorCode internalStatus = U_ZERO_ERROR;
651 if (date < getMinimum(UCAL_DATE) ||
652 date > monthLength(internalGetMonth(internalStatus), internalStatus) ||
653 U_FAILURE(internalStatus)) {
654 return false;
655 }
656 }
657
658 if (isSet(UCAL_DAY_OF_YEAR)) {
659 int32_t days = internalGet(UCAL_DAY_OF_YEAR);
660 if (days < 1 || days > yearLength()) {
661 return false;
662 }
663 }
664
665 // Handle DAY_OF_WEEK_IN_MONTH, which must not have the value zero.
666 // We've checked against minimum and maximum above already.
667 if (isSet(UCAL_DAY_OF_WEEK_IN_MONTH) &&
668 0 == internalGet(UCAL_DAY_OF_WEEK_IN_MONTH)) {
669 return false;
670 }
671
672 return true;
673 }
674
675 // -------------------------------------
676
677 UBool
boundsCheck(int32_t value,UCalendarDateFields field) const678 GregorianCalendar::boundsCheck(int32_t value, UCalendarDateFields field) const
679 {
680 return value >= getMinimum(field) && value <= getMaximum(field);
681 }
682
683 // -------------------------------------
684
685 UDate
getEpochDay(UErrorCode & status)686 GregorianCalendar::getEpochDay(UErrorCode& status)
687 {
688 complete(status);
689 // Divide by 1000 (convert to seconds) in order to prevent overflow when
690 // dealing with UDate(Long.MIN_VALUE) and UDate(Long.MAX_VALUE).
691 double wallSec = internalGetTime()/1000 + (internalGet(UCAL_ZONE_OFFSET) + internalGet(UCAL_DST_OFFSET))/1000;
692
693 return ClockMath::floorDivide(wallSec, kOneDay/1000.0);
694 }
695
696 // -------------------------------------
697
698
699 // -------------------------------------
700
701 /**
702 * Compute the julian day number of the day BEFORE the first day of
703 * January 1, year 1 of the given calendar. If julianDay == 0, it
704 * specifies (Jan. 1, 1) - 1, in whatever calendar we are using (Julian
705 * or Gregorian).
706 */
computeJulianDayOfYear(UBool isGregorian,int32_t year,UBool & isLeap)707 double GregorianCalendar::computeJulianDayOfYear(UBool isGregorian,
708 int32_t year, UBool& isLeap)
709 {
710 isLeap = year%4 == 0;
711 int32_t y = year - 1;
712 double julianDay = 365.0*y + ClockMath::floorDivide(y, 4) + (kJan1_1JulianDay - 3);
713
714 if (isGregorian) {
715 isLeap = isLeap && ((year%100 != 0) || (year%400 == 0));
716 // Add 2 because Gregorian calendar starts 2 days after Julian calendar
717 julianDay += Grego::gregorianShift(year);
718 }
719
720 return julianDay;
721 }
722
723 // /**
724 // * Compute the day of week, relative to the first day of week, from
725 // * 0..6, of the current DOW_LOCAL or DAY_OF_WEEK fields. This is
726 // * equivalent to get(DOW_LOCAL) - 1.
727 // */
728 // int32_t GregorianCalendar::computeRelativeDOW() const {
729 // int32_t relDow = 0;
730 // if (fStamp[UCAL_DOW_LOCAL] > fStamp[UCAL_DAY_OF_WEEK]) {
731 // relDow = internalGet(UCAL_DOW_LOCAL) - 1; // 1-based
732 // } else if (fStamp[UCAL_DAY_OF_WEEK] != kUnset) {
733 // relDow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
734 // if (relDow < 0) relDow += 7;
735 // }
736 // return relDow;
737 // }
738
739 // /**
740 // * Compute the day of week, relative to the first day of week,
741 // * from 0..6 of the given julian day.
742 // */
743 // int32_t GregorianCalendar::computeRelativeDOW(double julianDay) const {
744 // int32_t relDow = julianDayToDayOfWeek(julianDay) - getFirstDayOfWeek();
745 // if (relDow < 0) {
746 // relDow += 7;
747 // }
748 // return relDow;
749 // }
750
751 // /**
752 // * Compute the DOY using the WEEK_OF_YEAR field and the julian day
753 // * of the day BEFORE January 1 of a year (a return value from
754 // * computeJulianDayOfYear).
755 // */
756 // int32_t GregorianCalendar::computeDOYfromWOY(double julianDayOfYear) const {
757 // // Compute DOY from day of week plus week of year
758
759 // // Find the day of the week for the first of this year. This
760 // // is zero-based, with 0 being the locale-specific first day of
761 // // the week. Add 1 to get first day of year.
762 // int32_t fdy = computeRelativeDOW(julianDayOfYear + 1);
763
764 // return
765 // // Compute doy of first (relative) DOW of WOY 1
766 // (((7 - fdy) < getMinimalDaysInFirstWeek())
767 // ? (8 - fdy) : (1 - fdy))
768
769 // // Adjust for the week number.
770 // + (7 * (internalGet(UCAL_WEEK_OF_YEAR) - 1))
771
772 // // Adjust for the DOW
773 // + computeRelativeDOW();
774 // }
775
776 // -------------------------------------
777
778 double
millisToJulianDay(UDate millis)779 GregorianCalendar::millisToJulianDay(UDate millis)
780 {
781 return static_cast<double>(kEpochStartAsJulianDay) + ClockMath::floorDivide(millis, kOneDay);
782 }
783
784 // -------------------------------------
785
786 UDate
julianDayToMillis(double julian)787 GregorianCalendar::julianDayToMillis(double julian)
788 {
789 return static_cast<UDate>((julian - kEpochStartAsJulianDay) * kOneDay);
790 }
791
792 // -------------------------------------
793
794 int32_t
aggregateStamp(int32_t stamp_a,int32_t stamp_b)795 GregorianCalendar::aggregateStamp(int32_t stamp_a, int32_t stamp_b)
796 {
797 return (((stamp_a != kUnset && stamp_b != kUnset)
798 ? uprv_max(stamp_a, stamp_b)
799 : static_cast<int32_t>(kUnset)));
800 }
801
802 // -------------------------------------
803
804 /**
805 * Roll a field by a signed amount.
806 * Note: This will be made public later. [LIU]
807 */
808
809 void
roll(EDateFields field,int32_t amount,UErrorCode & status)810 GregorianCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) {
811 roll(static_cast<UCalendarDateFields>(field), amount, status);
812 }
813
814 void
roll(UCalendarDateFields field,int32_t amount,UErrorCode & status)815 GregorianCalendar::roll(UCalendarDateFields field, int32_t amount, UErrorCode& status) UPRV_NO_SANITIZE_UNDEFINED {
816 if((amount == 0) || U_FAILURE(status)) {
817 return;
818 }
819
820 // J81 processing. (gregorian cutover)
821 UBool inCutoverMonth = false;
822 int32_t cMonthLen=0; // 'c' for cutover; in days
823 int32_t cDayOfMonth=0; // no discontinuity: [0, cMonthLen)
824 double cMonthStart=0.0; // in ms
825
826 // Common code - see if we're in the cutover month of the cutover year
827 if(get(UCAL_EXTENDED_YEAR, status) == fGregorianCutoverYear) {
828 switch (field) {
829 case UCAL_DAY_OF_MONTH:
830 case UCAL_WEEK_OF_MONTH:
831 {
832 int32_t max = monthLength(internalGetMonth(status), status);
833 if (U_FAILURE(status)) {
834 return;
835 }
836 UDate t = internalGetTime();
837 // We subtract 1 from the DAY_OF_MONTH to make it zero-based, and an
838 // additional 10 if we are after the cutover. Thus the monthStart
839 // value will be correct iff we actually are in the cutover month.
840 cDayOfMonth = internalGet(UCAL_DAY_OF_MONTH) - ((t >= fGregorianCutover) ? 10 : 0);
841 cMonthStart = t - ((cDayOfMonth - 1) * kOneDay);
842 // A month containing the cutover is 10 days shorter.
843 if ((cMonthStart < fGregorianCutover) &&
844 (cMonthStart + (cMonthLen=(max-10))*kOneDay >= fGregorianCutover)) {
845 inCutoverMonth = true;
846 }
847 }
848 break;
849 default:
850 ;
851 }
852 }
853
854 switch (field) {
855 case UCAL_WEEK_OF_YEAR: {
856 // Unlike WEEK_OF_MONTH, WEEK_OF_YEAR never shifts the day of the
857 // week. Also, rolling the week of the year can have seemingly
858 // strange effects simply because the year of the week of year
859 // may be different from the calendar year. For example, the
860 // date Dec 28, 1997 is the first day of week 1 of 1998 (if
861 // weeks start on Sunday and the minimal days in first week is
862 // <= 3).
863 int32_t woy = get(UCAL_WEEK_OF_YEAR, status);
864 // Get the ISO year, which matches the week of year. This
865 // may be one year before or after the calendar year.
866 int32_t isoYear = get(UCAL_YEAR_WOY, status);
867 int32_t isoDoy = internalGet(UCAL_DAY_OF_YEAR);
868 int32_t month = internalGetMonth(status);
869 if (U_FAILURE(status)) {
870 return;
871 }
872 if (month == UCAL_JANUARY) {
873 if (woy >= 52) {
874 isoDoy += handleGetYearLength(isoYear);
875 }
876 } else {
877 if (woy == 1) {
878 isoDoy -= handleGetYearLength(isoYear - 1);
879 }
880 }
881 if (uprv_add32_overflow(woy, amount, &woy)) {
882 status = U_ILLEGAL_ARGUMENT_ERROR;
883 return;
884 }
885 // Do fast checks to avoid unnecessary computation:
886 if (woy < 1 || woy > 52) {
887 // Determine the last week of the ISO year.
888 // We do this using the standard formula we use
889 // everywhere in this file. If we can see that the
890 // days at the end of the year are going to fall into
891 // week 1 of the next year, we drop the last week by
892 // subtracting 7 from the last day of the year.
893 int32_t lastDoy = handleGetYearLength(isoYear);
894 int32_t lastRelDow = (lastDoy - isoDoy + internalGet(UCAL_DAY_OF_WEEK) -
895 getFirstDayOfWeek()) % 7;
896 if (lastRelDow < 0) lastRelDow += 7;
897 if ((6 - lastRelDow) >= getMinimalDaysInFirstWeek()) lastDoy -= 7;
898 int32_t lastWoy = weekNumber(lastDoy, lastRelDow + 1);
899 woy = ((woy + lastWoy - 1) % lastWoy) + 1;
900 }
901 set(UCAL_WEEK_OF_YEAR, woy);
902 set(UCAL_YEAR_WOY,isoYear);
903 return;
904 }
905
906 case UCAL_DAY_OF_MONTH:
907 if( !inCutoverMonth ) {
908 Calendar::roll(field, amount, status);
909 return;
910 }
911 {
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 }
935 {
936 #if defined (U_DEBUG_CAL)
937 fprintf(stderr, "%s:%d: roll WOM %d ??????????????????? \n",
938 __FILE__, __LINE__,amount);
939 #endif
940 // NOTE: following copied from the old
941 // GregorianCalendar::roll( WEEK_OF_MONTH ) code
942
943 // This is tricky, because during the roll we may have to shift
944 // to a different day of the week. For example:
945
946 // s m t w r f s
947 // 1 2 3 4 5
948 // 6 7 8 9 10 11 12
949
950 // When rolling from the 6th or 7th back one week, we go to the
951 // 1st (assuming that the first partial week counts). The same
952 // thing happens at the end of the month.
953
954 // The other tricky thing is that we have to figure out whether
955 // the first partial week actually counts or not, based on the
956 // minimal first days in the week. And we have to use the
957 // correct first day of the week to delineate the week
958 // boundaries.
959
960 // Here's our algorithm. First, we find the real boundaries of
961 // the month. Then we discard the first partial week if it
962 // doesn't count in this locale. Then we fill in the ends with
963 // phantom days, so that the first partial week and the last
964 // partial week are full weeks. We then have a nice square
965 // block of weeks. We do the usual rolling within this block,
966 // as is done elsewhere in this method. If we wind up on one of
967 // the phantom days that we added, we recognize this and pin to
968 // the first or the last day of the month. Easy, eh?
969
970 // Another wrinkle: To fix jitterbug 81, we have to make all this
971 // work in the oddball month containing the Gregorian cutover.
972 // This month is 10 days shorter than usual, and also contains
973 // a discontinuity in the days; e.g., the default cutover month
974 // is Oct 1582, and goes from day of month 4 to day of month 15.
975
976 // Normalize the DAY_OF_WEEK so that 0 is the first day of the week
977 // in this locale. We have dow in 0..6.
978 int32_t dow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
979 if (dow < 0)
980 dow += 7;
981
982 // Find the day of month, compensating for cutover discontinuity.
983 int32_t dom = cDayOfMonth;
984
985 // Find the day of the week (normalized for locale) for the first
986 // of the month.
987 int32_t fdm = (dow - dom + 1) % 7;
988 if (fdm < 0)
989 fdm += 7;
990
991 // Get the first day of the first full week of the month,
992 // including phantom days, if any. Figure out if the first week
993 // counts or not; if it counts, then fill in phantom days. If
994 // not, advance to the first real full week (skip the partial week).
995 int32_t start;
996 if ((7 - fdm) < getMinimalDaysInFirstWeek())
997 start = 8 - fdm; // Skip the first partial week
998 else
999 start = 1 - fdm; // This may be zero or negative
1000
1001 // Get the day of the week (normalized for locale) for the last
1002 // day of the month.
1003 int32_t monthLen = cMonthLen;
1004 int32_t ldm = (monthLen - dom + dow) % 7;
1005 // We know monthLen >= DAY_OF_MONTH so we skip the += 7 step here.
1006
1007 // Get the limit day for the blocked-off rectangular month; that
1008 // is, the day which is one past the last day of the month,
1009 // after the month has already been filled in with phantom days
1010 // to fill out the last week. This day has a normalized DOW of 0.
1011 int32_t limit = monthLen + 7 - ldm;
1012
1013 // Now roll between start and (limit - 1).
1014 int32_t gap = limit - start;
1015 int32_t newDom = (dom + amount*7 - start) % gap;
1016 if (newDom < 0)
1017 newDom += gap;
1018 newDom += start;
1019
1020 // Finally, pin to the real start and end of the month.
1021 if (newDom < 1)
1022 newDom = 1;
1023 if (newDom > monthLen)
1024 newDom = monthLen;
1025
1026 // Set the DAY_OF_MONTH. We rely on the fact that this field
1027 // takes precedence over everything else (since all other fields
1028 // are also set at this point). If this fact changes (if the
1029 // disambiguation algorithm changes) then we will have to unset
1030 // the appropriate fields here so that DAY_OF_MONTH is attended
1031 // to.
1032
1033 // If we are in the cutover month, manipulate ms directly. Don't do
1034 // this in general because it doesn't work across DST boundaries
1035 // (details, details). This takes care of the discontinuity.
1036 setTimeInMillis(cMonthStart + (newDom-1)*kOneDay, status);
1037 return;
1038 }
1039
1040 default:
1041 Calendar::roll(field, amount, status);
1042 return;
1043 }
1044 }
1045
1046 // -------------------------------------
1047
1048
1049 /**
1050 * Return the minimum value that this field could have, given the current date.
1051 * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1052 * @param field the time field.
1053 * @return the minimum value that this field could have, given the current date.
1054 * @deprecated ICU 2.6. Use getActualMinimum(UCalendarDateFields field) instead.
1055 */
getActualMinimum(EDateFields field) const1056 int32_t GregorianCalendar::getActualMinimum(EDateFields field) const
1057 {
1058 return getMinimum(static_cast<UCalendarDateFields>(field));
1059 }
1060
getActualMinimum(EDateFields field,UErrorCode &) const1061 int32_t GregorianCalendar::getActualMinimum(EDateFields field, UErrorCode& /* status */) const
1062 {
1063 return getMinimum(static_cast<UCalendarDateFields>(field));
1064 }
1065
1066 /**
1067 * Return the minimum value that this field could have, given the current date.
1068 * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1069 * @param field the time field.
1070 * @return the minimum value that this field could have, given the current date.
1071 * @draft ICU 2.6.
1072 */
getActualMinimum(UCalendarDateFields field,UErrorCode &) const1073 int32_t GregorianCalendar::getActualMinimum(UCalendarDateFields field, UErrorCode& /* status */) const
1074 {
1075 return getMinimum(field);
1076 }
1077
1078
1079 // ------------------------------------
1080
1081 /**
1082 * Old year limits were least max 292269054, max 292278994.
1083 */
1084
1085 /**
1086 * @stable ICU 2.0
1087 */
handleGetLimit(UCalendarDateFields field,ELimitType limitType) const1088 int32_t GregorianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
1089 return kGregorianCalendarLimits[field][limitType];
1090 }
1091
1092 /**
1093 * Return the maximum value that this field could have, given the current date.
1094 * For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual
1095 * maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar,
1096 * for some years the actual maximum for MONTH is 12, and for others 13.
1097 * @stable ICU 2.0
1098 */
getActualMaximum(UCalendarDateFields field,UErrorCode & status) const1099 int32_t GregorianCalendar::getActualMaximum(UCalendarDateFields field, UErrorCode& status) const
1100 {
1101 /* It is a known limitation that the code here (and in getActualMinimum)
1102 * won't behave properly at the extreme limits of GregorianCalendar's
1103 * representable range (except for the code that handles the YEAR
1104 * field). That's because the ends of the representable range are at
1105 * odd spots in the year. For calendars with the default Gregorian
1106 * cutover, these limits are Sun Dec 02 16:47:04 GMT 292269055 BC to Sun
1107 * Aug 17 07:12:55 GMT 292278994 AD, somewhat different for non-GMT
1108 * zones. As a result, if the calendar is set to Aug 1 292278994 AD,
1109 * the actual maximum of DAY_OF_MONTH is 17, not 30. If the date is Mar
1110 * 31 in that year, the actual maximum month might be Jul, whereas is
1111 * the date is Mar 15, the actual maximum might be Aug -- depending on
1112 * the precise semantics that are desired. Similar considerations
1113 * affect all fields. Nonetheless, this effect is sufficiently arcane
1114 * that we permit it, rather than complicating the code to handle such
1115 * intricacies. - liu 8/20/98
1116
1117 * UPDATE: No longer true, since we have pulled in the limit values on
1118 * the year. - Liu 11/6/00 */
1119
1120 switch (field) {
1121
1122 case UCAL_YEAR:
1123 /* The year computation is no different, in principle, from the
1124 * others, however, the range of possible maxima is large. In
1125 * addition, the way we know we've exceeded the range is different.
1126 * For these reasons, we use the special case code below to handle
1127 * this field.
1128 *
1129 * The actual maxima for YEAR depend on the type of calendar:
1130 *
1131 * Gregorian = May 17, 292275056 BC - Aug 17, 292278994 AD
1132 * Julian = Dec 2, 292269055 BC - Jan 3, 292272993 AD
1133 * Hybrid = Dec 2, 292269055 BC - Aug 17, 292278994 AD
1134 *
1135 * We know we've exceeded the maximum when either the month, date,
1136 * time, or era changes in response to setting the year. We don't
1137 * check for month, date, and time here because the year and era are
1138 * sufficient to detect an invalid year setting. NOTE: If code is
1139 * added to check the month and date in the future for some reason,
1140 * Feb 29 must be allowed to shift to Mar 1 when setting the year.
1141 */
1142 {
1143 if(U_FAILURE(status)) return 0;
1144 Calendar *cal = clone();
1145 if(!cal) {
1146 status = U_MEMORY_ALLOCATION_ERROR;
1147 return 0;
1148 }
1149
1150 cal->setLenient(true);
1151
1152 int32_t era = cal->get(UCAL_ERA, status);
1153 UDate d = cal->getTime(status);
1154
1155 /* Perform a binary search, with the invariant that lowGood is a
1156 * valid year, and highBad is an out of range year.
1157 */
1158 int32_t lowGood = kGregorianCalendarLimits[UCAL_YEAR][1];
1159 int32_t highBad = kGregorianCalendarLimits[UCAL_YEAR][2]+1;
1160 while ((lowGood + 1) < highBad) {
1161 int32_t y = (lowGood + highBad) / 2;
1162 cal->set(UCAL_YEAR, y);
1163 if (cal->get(UCAL_YEAR, status) == y && cal->get(UCAL_ERA, status) == era) {
1164 lowGood = y;
1165 } else {
1166 highBad = y;
1167 cal->setTime(d, status); // Restore original fields
1168 }
1169 }
1170
1171 delete cal;
1172 return lowGood;
1173 }
1174
1175 default:
1176 return Calendar::getActualMaximum(field,status);
1177 }
1178 }
1179
1180
handleGetExtendedYear(UErrorCode & status)1181 int32_t GregorianCalendar::handleGetExtendedYear(UErrorCode& status) {
1182 if (U_FAILURE(status)) {
1183 return 0;
1184 }
1185 // the year to return
1186 int32_t year = kEpochYear;
1187
1188 // year field to use
1189 int32_t yearField = UCAL_EXTENDED_YEAR;
1190
1191 // There are three separate fields which could be used to
1192 // derive the proper year. Use the one most recently set.
1193 if (fStamp[yearField] < fStamp[UCAL_YEAR])
1194 yearField = UCAL_YEAR;
1195 if (fStamp[yearField] < fStamp[UCAL_YEAR_WOY])
1196 yearField = UCAL_YEAR_WOY;
1197
1198 // based on the "best" year field, get the year
1199 switch(yearField) {
1200 case UCAL_EXTENDED_YEAR:
1201 year = internalGet(UCAL_EXTENDED_YEAR, kEpochYear);
1202 break;
1203
1204 case UCAL_YEAR:
1205 {
1206 // The year defaults to the epoch start, the era to AD
1207 int32_t era = internalGet(UCAL_ERA, AD);
1208 if (era == BC) {
1209 year = 1 - internalGet(UCAL_YEAR, 1); // Convert to extended year
1210 } else if (era == AD) {
1211 year = internalGet(UCAL_YEAR, kEpochYear);
1212 } else {
1213 status = U_ILLEGAL_ARGUMENT_ERROR;
1214 return 0;
1215 }
1216 }
1217 break;
1218
1219 case UCAL_YEAR_WOY:
1220 year = handleGetExtendedYearFromWeekFields(
1221 internalGet(UCAL_YEAR_WOY), internalGet(UCAL_WEEK_OF_YEAR), status);
1222 if (U_FAILURE(status)) {
1223 return 0;
1224 }
1225 #if defined (U_DEBUG_CAL)
1226 // if(internalGet(UCAL_YEAR_WOY) != year) {
1227 fprintf(stderr, "%s:%d: hGEYFWF[%d,%d] -> %d\n",
1228 __FILE__, __LINE__,internalGet(UCAL_YEAR_WOY),internalGet(UCAL_WEEK_OF_YEAR),year);
1229 //}
1230 #endif
1231 break;
1232
1233 default:
1234 year = kEpochYear;
1235 }
1236 return year;
1237 }
1238
handleGetExtendedYearFromWeekFields(int32_t yearWoy,int32_t woy,UErrorCode & status)1239 int32_t GregorianCalendar::handleGetExtendedYearFromWeekFields(int32_t yearWoy, int32_t woy, UErrorCode& status)
1240 {
1241 if (U_FAILURE(status)) {
1242 return 0;
1243 }
1244 // convert year to extended form
1245 int32_t era = internalGet(UCAL_ERA, AD);
1246 if(era == BC) {
1247 yearWoy = 1 - yearWoy;
1248 }
1249 return Calendar::handleGetExtendedYearFromWeekFields(yearWoy, woy, status);
1250 }
1251
1252
1253 // -------------------------------------
1254
1255 /**
1256 * Return the ERA. We need a special method for this because the
1257 * default ERA is AD, but a zero (unset) ERA is BC.
1258 */
1259 int32_t
internalGetEra() const1260 GregorianCalendar::internalGetEra() const {
1261 return isSet(UCAL_ERA) ? internalGet(UCAL_ERA) : static_cast<int32_t>(AD);
1262 }
1263
1264 const char *
getType() const1265 GregorianCalendar::getType() const {
1266 //static const char kGregorianType = "gregorian";
1267
1268 return "gregorian";
1269 }
1270
1271 IMPL_SYSTEM_DEFAULT_CENTURY(GregorianCalendar, "@calendar=gregory")
1272
1273 U_NAMESPACE_END
1274
1275 #endif /* #if !UCONFIG_NO_FORMATTING */
1276
1277 //eof
1278