1 /*
2 ******************************************************************************
3 * Copyright (C) 2003-2006, International Business Machines Corporation
4 * and others. All Rights Reserved.
5 ******************************************************************************
6 *
7 * File ISLAMCAL.H
8 *
9 * Modification History:
10 *
11 * Date Name Description
12 * 10/14/2003 srl ported from java IslamicCalendar
13 *****************************************************************************
14 */
15
16 #include "islamcal.h"
17
18 #if !UCONFIG_NO_FORMATTING
19
20 #include "umutex.h"
21 #include <float.h>
22 #include "gregoimp.h" // Math
23 #include "astro.h" // CalendarAstronomer
24 #include "uhash.h"
25 #include "ucln_in.h"
26
27 static const UDate HIJRA_MILLIS = -42521587200000.0; // 7/16/622 AD 00:00
28
29 // Debugging
30 #ifdef U_DEBUG_ISLAMCAL
31 # include <stdio.h>
32 # include <stdarg.h>
debug_islamcal_loc(const char * f,int32_t l)33 static void debug_islamcal_loc(const char *f, int32_t l)
34 {
35 fprintf(stderr, "%s:%d: ", f, l);
36 }
37
debug_islamcal_msg(const char * pat,...)38 static void debug_islamcal_msg(const char *pat, ...)
39 {
40 va_list ap;
41 va_start(ap, pat);
42 vfprintf(stderr, pat, ap);
43 fflush(stderr);
44 }
45 // must use double parens, i.e.: U_DEBUG_ISLAMCAL_MSG(("four is: %d",4));
46 #define U_DEBUG_ISLAMCAL_MSG(x) {debug_islamcal_loc(__FILE__,__LINE__);debug_islamcal_msg x;}
47 #else
48 #define U_DEBUG_ISLAMCAL_MSG(x)
49 #endif
50
51
52 // --- The cache --
53 // cache of months
54 static UMTX astroLock = 0; // pod bay door lock
55 static U_NAMESPACE_QUALIFIER CalendarCache *gMonthCache = NULL;
56 static U_NAMESPACE_QUALIFIER CalendarAstronomer *gIslamicCalendarAstro = NULL;
57
58 U_CDECL_BEGIN
calendar_islamic_cleanup(void)59 static UBool calendar_islamic_cleanup(void) {
60 if (gMonthCache) {
61 delete gMonthCache;
62 gMonthCache = NULL;
63 }
64 if (gIslamicCalendarAstro) {
65 delete gIslamicCalendarAstro;
66 gIslamicCalendarAstro = NULL;
67 }
68 umtx_destroy(&astroLock);
69 return TRUE;
70 }
71 U_CDECL_END
72
73 U_NAMESPACE_BEGIN
74
75 // Implementation of the IslamicCalendar class
76
77 //-------------------------------------------------------------------------
78 // Constructors...
79 //-------------------------------------------------------------------------
80
getType() const81 const char *IslamicCalendar::getType() const {
82 if(civil==CIVIL) {
83 return "islamic-civil";
84 } else {
85 return "islamic";
86 }
87 }
88
clone() const89 Calendar* IslamicCalendar::clone() const {
90 return new IslamicCalendar(*this);
91 }
92
IslamicCalendar(const Locale & aLocale,UErrorCode & success,ECivil beCivil)93 IslamicCalendar::IslamicCalendar(const Locale& aLocale, UErrorCode& success, ECivil beCivil)
94 : Calendar(TimeZone::createDefault(), aLocale, success),
95 civil(beCivil)
96 {
97 setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
98 }
99
IslamicCalendar(const IslamicCalendar & other)100 IslamicCalendar::IslamicCalendar(const IslamicCalendar& other) : Calendar(other), civil(other.civil) {
101 }
102
~IslamicCalendar()103 IslamicCalendar::~IslamicCalendar()
104 {
105 }
106
107 /**
108 * Determines whether this object uses the fixed-cycle Islamic civil calendar
109 * or an approximation of the religious, astronomical calendar.
110 *
111 * @param beCivil <code>true</code> to use the civil calendar,
112 * <code>false</code> to use the astronomical calendar.
113 * @draft ICU 2.4
114 */
setCivil(ECivil beCivil,UErrorCode & status)115 void IslamicCalendar::setCivil(ECivil beCivil, UErrorCode &status)
116 {
117 if (civil != beCivil) {
118 // The fields of the calendar will become invalid, because the calendar
119 // rules are different
120 UDate m = getTimeInMillis(status);
121 civil = beCivil;
122 clear();
123 setTimeInMillis(m, status);
124 }
125 }
126
127 /**
128 * Returns <code>true</code> if this object is using the fixed-cycle civil
129 * calendar, or <code>false</code> if using the religious, astronomical
130 * calendar.
131 * @draft ICU 2.4
132 */
isCivil()133 UBool IslamicCalendar::isCivil() {
134 return (civil == CIVIL);
135 }
136
137 //-------------------------------------------------------------------------
138 // Minimum / Maximum access functions
139 //-------------------------------------------------------------------------
140
141 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
142 // Minimum Greatest Least Maximum
143 // Minimum Maximum
144 { 0, 0, 0, 0 }, // ERA
145 { 1, 1, 5000000, 5000000 }, // YEAR
146 { 0, 0, 11, 11 }, // MONTH
147 { 1, 1, 50, 51 }, // WEEK_OF_YEAR
148 { 0, 0, 4, 6 }, // WEEK_OF_MONTH
149 { 1, 1, 29, 30 }, // DAY_OF_MONTH
150 { 1, 1, 354, 355 }, // DAY_OF_YEAR
151 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
152 { -1, -1, 5, 5 }, // DAY_OF_WEEK_IN_MONTH
153 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
154 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
155 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
156 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
157 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
158 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
159 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
160 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
161 { 1, 1, 5000001, 5000001 }, // YEAR_WOY
162 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
163 { 1, 1, 5000000, 5000000 }, // EXTENDED_YEAR
164 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
165 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1} // MILLISECONDS_IN_DAY
166 };
167
168 /**
169 * @draft ICU 2.4
170 */
handleGetLimit(UCalendarDateFields field,ELimitType limitType) const171 int32_t IslamicCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
172 return LIMITS[field][limitType];
173 }
174
175 //-------------------------------------------------------------------------
176 // Assorted calculation utilities
177 //
178
179 /**
180 * Determine whether a year is a leap year in the Islamic civil calendar
181 */
civilLeapYear(int32_t year)182 UBool IslamicCalendar::civilLeapYear(int32_t year)
183 {
184 return (14 + 11 * year) % 30 < 11;
185 }
186
187 /**
188 * Return the day # on which the given year starts. Days are counted
189 * from the Hijri epoch, origin 0.
190 */
yearStart(int32_t year)191 int32_t IslamicCalendar::yearStart(int32_t year) {
192 if (civil == CIVIL) {
193 return (year-1)*354 + Math::floorDivide((3+11*year),30);
194 } else {
195 return trueMonthStart(12*(year-1));
196 }
197 }
198
199 /**
200 * Return the day # on which the given month starts. Days are counted
201 * from the Hijri epoch, origin 0.
202 *
203 * @param year The hijri year
204 * @param year The hijri month, 0-based
205 */
monthStart(int32_t year,int32_t month) const206 int32_t IslamicCalendar::monthStart(int32_t year, int32_t month) const {
207 if (civil == CIVIL) {
208 return (int32_t)uprv_ceil(29.5*month)
209 + (year-1)*354 + (int32_t)Math::floorDivide((3+11*year),30);
210 } else {
211 return trueMonthStart(12*(year-1) + month);
212 }
213 }
214
215 /**
216 * Find the day number on which a particular month of the true/lunar
217 * Islamic calendar starts.
218 *
219 * @param month The month in question, origin 0 from the Hijri epoch
220 *
221 * @return The day number on which the given month starts.
222 */
trueMonthStart(int32_t month) const223 int32_t IslamicCalendar::trueMonthStart(int32_t month) const
224 {
225 UErrorCode status = U_ZERO_ERROR;
226 int32_t start = CalendarCache::get(&gMonthCache, month, status);
227
228 if (start==0) {
229 // Make a guess at when the month started, using the average length
230 UDate origin = HIJRA_MILLIS
231 + uprv_floor(month * CalendarAstronomer::SYNODIC_MONTH - 1) * kOneDay;
232
233 double age = moonAge(origin);
234
235 if (moonAge(origin) >= 0) {
236 // The month has already started
237 do {
238 origin -= kOneDay;
239 age = moonAge(origin);
240 } while (age >= 0);
241 }
242 else {
243 // Preceding month has not ended yet.
244 do {
245 origin += kOneDay;
246 age = moonAge(origin);
247 } while (age < 0);
248 }
249 start = (int32_t)Math::floorDivide((origin - HIJRA_MILLIS), (double)kOneDay) + 1;
250 CalendarCache::put(&gMonthCache, month, start, status);
251 }
252 if(U_FAILURE(status)) {
253 start = 0;
254 }
255 return start;
256 }
257
258 /**
259 * Return the "age" of the moon at the given time; this is the difference
260 * in ecliptic latitude between the moon and the sun. This method simply
261 * calls CalendarAstronomer.moonAge, converts to degrees,
262 * and adjusts the result to be in the range [-180, 180].
263 *
264 * @param time The time at which the moon's age is desired,
265 * in millis since 1/1/1970.
266 */
moonAge(UDate time)267 double IslamicCalendar::moonAge(UDate time)
268 {
269 double age = 0;
270
271 umtx_lock(&astroLock);
272 if(gIslamicCalendarAstro == NULL) {
273 gIslamicCalendarAstro = new CalendarAstronomer();
274 }
275 gIslamicCalendarAstro->setTime(time);
276 age = gIslamicCalendarAstro->getMoonAge();
277 ucln_i18n_registerCleanup(UCLN_I18N_ISLAMIC_CALENDAR, calendar_islamic_cleanup);
278 umtx_unlock(&astroLock);
279
280 // Convert to degrees and normalize...
281 age = age * 180 / CalendarAstronomer::PI;
282 if (age > 180) {
283 age = age - 360;
284 }
285
286 return age;
287 }
288
289 //----------------------------------------------------------------------
290 // Calendar framework
291 //----------------------------------------------------------------------
292
293 /**
294 * Return the length (in days) of the given month.
295 *
296 * @param year The hijri year
297 * @param year The hijri month, 0-based
298 * @draft ICU 2.4
299 */
handleGetMonthLength(int32_t extendedYear,int32_t month) const300 int32_t IslamicCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
301
302 int32_t length = 0;
303
304 if (civil == CIVIL) {
305 length = 29 + (month+1) % 2;
306 if (month == DHU_AL_HIJJAH && civilLeapYear(extendedYear)) {
307 length++;
308 }
309 } else {
310 month = 12*(extendedYear-1) + month;
311 length = trueMonthStart(month+1) - trueMonthStart(month) ;
312 }
313 return length;
314 }
315
316 /**
317 * Return the number of days in the given Islamic year
318 * @draft ICU 2.4
319 */
handleGetYearLength(int32_t extendedYear) const320 int32_t IslamicCalendar::handleGetYearLength(int32_t extendedYear) const {
321 if (civil == CIVIL) {
322 return 354 + (civilLeapYear(extendedYear) ? 1 : 0);
323 } else {
324 int32_t month = 12*(extendedYear-1);
325 return (trueMonthStart(month + 12) - trueMonthStart(month));
326 }
327 }
328
329 //-------------------------------------------------------------------------
330 // Functions for converting from field values to milliseconds....
331 //-------------------------------------------------------------------------
332
333 // Return JD of start of given month/year
334 /**
335 * @draft ICU 2.4
336 */
handleComputeMonthStart(int32_t eyear,int32_t month,UBool) const337 int32_t IslamicCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */) const {
338 return monthStart(eyear, month) + 1948439;
339 }
340
341 //-------------------------------------------------------------------------
342 // Functions for converting from milliseconds to field values
343 //-------------------------------------------------------------------------
344
345 /**
346 * @draft ICU 2.4
347 */
handleGetExtendedYear()348 int32_t IslamicCalendar::handleGetExtendedYear() {
349 int32_t year;
350 if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
351 year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
352 } else {
353 year = internalGet(UCAL_YEAR, 1); // Default to year 1
354 }
355 return year;
356 }
357
358 /**
359 * Override Calendar to compute several fields specific to the Islamic
360 * calendar system. These are:
361 *
362 * <ul><li>ERA
363 * <li>YEAR
364 * <li>MONTH
365 * <li>DAY_OF_MONTH
366 * <li>DAY_OF_YEAR
367 * <li>EXTENDED_YEAR</ul>
368 *
369 * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
370 * method is called. The getGregorianXxx() methods return Gregorian
371 * calendar equivalents for the given Julian day.
372 * @draft ICU 2.4
373 */
handleComputeFields(int32_t julianDay,UErrorCode &)374 void IslamicCalendar::handleComputeFields(int32_t julianDay, UErrorCode &/*status*/) {
375 int32_t year, month, dayOfMonth, dayOfYear;
376 UDate startDate;
377 int32_t days = julianDay - 1948440;
378
379 if (civil == CIVIL) {
380 // Use the civil calendar approximation, which is just arithmetic
381 year = (int)Math::floorDivide( (double)(30 * days + 10646) , 10631.0 );
382 month = (int32_t)uprv_ceil((days - 29 - yearStart(year)) / 29.5 );
383 month = month<11?month:11;
384 startDate = monthStart(year, month);
385 } else {
386 // Guess at the number of elapsed full months since the epoch
387 int32_t months = (int32_t)uprv_floor((double)days / CalendarAstronomer::SYNODIC_MONTH);
388
389 startDate = uprv_floor(months * CalendarAstronomer::SYNODIC_MONTH - 1);
390
391 if ( days - startDate >= 28 && moonAge(internalGetTime()) > 0) {
392 // If we're near the end of the month, assume next month and search backwards
393 months++;
394 }
395
396 // Find out the last time that the new moon was actually visible at this longitude
397 // This returns midnight the night that the moon was visible at sunset.
398 while ((startDate = trueMonthStart(months)) > days) {
399 // If it was after the date in question, back up a month and try again
400 months--;
401 }
402
403 year = months / 12 + 1;
404 month = months % 12;
405 }
406
407 dayOfMonth = (days - monthStart(year, month)) + 1;
408
409 // Now figure out the day of the year.
410 dayOfYear = (days - monthStart(year, 0) + 1);
411
412 internalSet(UCAL_ERA, 0);
413 internalSet(UCAL_YEAR, year);
414 internalSet(UCAL_EXTENDED_YEAR, year);
415 internalSet(UCAL_MONTH, month);
416 internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
417 internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
418 }
419
420 UBool
inDaylightTime(UErrorCode & status) const421 IslamicCalendar::inDaylightTime(UErrorCode& status) const
422 {
423 // copied from GregorianCalendar
424 if (U_FAILURE(status) || !getTimeZone().useDaylightTime())
425 return FALSE;
426
427 // Force an update of the state of the Calendar.
428 ((IslamicCalendar*)this)->complete(status); // cast away const
429
430 return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
431 }
432
433 // default century
434 const UDate IslamicCalendar::fgSystemDefaultCentury = DBL_MIN;
435 const int32_t IslamicCalendar::fgSystemDefaultCenturyYear = -1;
436
437 UDate IslamicCalendar::fgSystemDefaultCenturyStart = DBL_MIN;
438 int32_t IslamicCalendar::fgSystemDefaultCenturyStartYear = -1;
439
440
haveDefaultCentury() const441 UBool IslamicCalendar::haveDefaultCentury() const
442 {
443 return TRUE;
444 }
445
defaultCenturyStart() const446 UDate IslamicCalendar::defaultCenturyStart() const
447 {
448 return internalGetDefaultCenturyStart();
449 }
450
defaultCenturyStartYear() const451 int32_t IslamicCalendar::defaultCenturyStartYear() const
452 {
453 return internalGetDefaultCenturyStartYear();
454 }
455
456 UDate
internalGetDefaultCenturyStart() const457 IslamicCalendar::internalGetDefaultCenturyStart() const
458 {
459 // lazy-evaluate systemDefaultCenturyStart
460 UBool needsUpdate;
461 UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
462
463 if (needsUpdate) {
464 initializeSystemDefaultCentury();
465 }
466
467 // use defaultCenturyStart unless it's the flag value;
468 // then use systemDefaultCenturyStart
469
470 return fgSystemDefaultCenturyStart;
471 }
472
473 int32_t
internalGetDefaultCenturyStartYear() const474 IslamicCalendar::internalGetDefaultCenturyStartYear() const
475 {
476 // lazy-evaluate systemDefaultCenturyStartYear
477 UBool needsUpdate;
478 UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
479
480 if (needsUpdate) {
481 initializeSystemDefaultCentury();
482 }
483
484 // use defaultCenturyStart unless it's the flag value;
485 // then use systemDefaultCenturyStartYear
486
487 return fgSystemDefaultCenturyStartYear;
488 }
489
490 void
initializeSystemDefaultCentury()491 IslamicCalendar::initializeSystemDefaultCentury()
492 {
493 // initialize systemDefaultCentury and systemDefaultCenturyYear based
494 // on the current time. They'll be set to 80 years before
495 // the current time.
496 // No point in locking as it should be idempotent.
497 if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury)
498 {
499 UErrorCode status = U_ZERO_ERROR;
500 IslamicCalendar calendar(Locale("@calendar=islamic-civil"),status);
501 if (U_SUCCESS(status))
502 {
503 calendar.setTime(Calendar::getNow(), status);
504 calendar.add(UCAL_YEAR, -80, status);
505 UDate newStart = calendar.getTime(status);
506 int32_t newYear = calendar.get(UCAL_YEAR, status);
507 {
508 umtx_lock(NULL);
509 fgSystemDefaultCenturyStart = newStart;
510 fgSystemDefaultCenturyStartYear = newYear;
511 umtx_unlock(NULL);
512 }
513 }
514 // We have no recourse upon failure unless we want to propagate the failure
515 // out.
516 }
517 }
518
519 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IslamicCalendar)
520
521 U_NAMESPACE_END
522
523 #endif
524
525