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1 /*
2 ******************************************************************************
3 * Copyright (C) 2003-2013, 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 #include "uassert.h"
27 
28 static const UDate HIJRA_MILLIS = -42521587200000.0;    // 7/16/622 AD 00:00
29 
30 // Debugging
31 #ifdef U_DEBUG_ISLAMCAL
32 # include <stdio.h>
33 # include <stdarg.h>
debug_islamcal_loc(const char * f,int32_t l)34 static void debug_islamcal_loc(const char *f, int32_t l)
35 {
36     fprintf(stderr, "%s:%d: ", f, l);
37 }
38 
debug_islamcal_msg(const char * pat,...)39 static void debug_islamcal_msg(const char *pat, ...)
40 {
41     va_list ap;
42     va_start(ap, pat);
43     vfprintf(stderr, pat, ap);
44     fflush(stderr);
45 }
46 // must use double parens, i.e.:  U_DEBUG_ISLAMCAL_MSG(("four is: %d",4));
47 #define U_DEBUG_ISLAMCAL_MSG(x) {debug_islamcal_loc(__FILE__,__LINE__);debug_islamcal_msg x;}
48 #else
49 #define U_DEBUG_ISLAMCAL_MSG(x)
50 #endif
51 
52 
53 // --- The cache --
54 // cache of months
55 static UMutex astroLock = U_MUTEX_INITIALIZER;  // pod bay door lock
56 static icu::CalendarCache *gMonthCache = NULL;
57 static icu::CalendarAstronomer *gIslamicCalendarAstro = NULL;
58 
59 U_CDECL_BEGIN
calendar_islamic_cleanup(void)60 static UBool calendar_islamic_cleanup(void) {
61     if (gMonthCache) {
62         delete gMonthCache;
63         gMonthCache = NULL;
64     }
65     if (gIslamicCalendarAstro) {
66         delete gIslamicCalendarAstro;
67         gIslamicCalendarAstro = NULL;
68     }
69     return TRUE;
70 }
71 U_CDECL_END
72 
73 U_NAMESPACE_BEGIN
74 
75 // Implementation of the IslamicCalendar class
76 
77 /**
78  * Friday EPOC
79  */
80 static const int32_t CIVIL_EPOC = 1948440;
81 
82 /**
83   * Thursday EPOC
84   */
85 static const int32_t ASTRONOMICAL_EPOC = 1948439;
86 
87 
88 static const int32_t UMALQURA_YEAR_START = 1318;
89 static const int32_t UMALQURA_YEAR_END = 1480;
90 
91 static const int UMALQURA_MONTHLENGTH[] = {
92     //* 1318 -1322 */ "0101 0111 0100", "1001 0111 0110", "0100 1011 0111", "0010 0101 0111", "0101 0010 1011",
93                             0x0574,           0x0975,           0x06A7,           0x0257,           0x052B,
94     //* 1323 -1327 */ "0110 1001 0101", "0110 1100 1010", "1010 1101 0101", "0101 0101 1011", "0010 0101 1101",
95                             0x0695,           0x06CA,           0x0AD5,           0x055B,           0x025B,
96     //* 1328 -1332 */ "1001 0010 1101", "1100 1001 0101", "1101 0100 1010", "1110 1010 0101", "0110 1101 0010",
97                             0x092D,           0x0C95,           0x0D4A,           0x0E5B,           0x025B,
98     //* 1333 -1337 */ "1010 1101 0101", "0101 0101 1010", "1010 1010 1011", "0100 0100 1011", "0110 1010 0101",
99                             0x0AD5,           0x055A,           0x0AAB,           0x044B,           0x06A5,
100     //* 1338 -1342 */ "0111 0101 0010", "1011 1010 1001", "0011 0111 0100", "1010 1011 0110", "0101 0101 0110",
101                             0x0752,           0x0BA9,           0x0374,           0x0AB6,           0x0556,
102     //* 1343 -1347 */ "1010 1010 1010", "1101 0101 0010", "1101 1010 1001", "0101 1101 0100", "1010 1110 1010",
103                             0x0AAA,           0x0D52,           0x0DA9,           0x05D4,           0x0AEA,
104     //* 1348 -1352 */ "0100 1101 1101", "0010 0110 1110", "1001 0010 1110", "1010 1010 0110", "1101 0101 0100",
105                             0x04DD,           0x026E,           0x092E,           0x0AA6,           0x0D54,
106     //* 1353 -1357 */ "0101 1010 1010", "0101 1011 0101", "0010 1011 0100", "1001 0011 0111", "0100 1001 1011",
107                             0x05AA,           0x05B5,           0x02B4,           0x0937,           0x049B,
108     //* 1358 -1362 */ "1010 0100 1011", "1011 0010 0101", "1011 0101 0100", "1011 0110 1010", "0101 0110 1101",
109                             0x0A4B,           0x0B25,           0x0B54,           0x0B6A,           0x056D,
110     //* 1363 -1367 */ "0100 1010 1101", "1010 0101 0101", "1101 0010 0101", "1110 1001 0010", "1110 1100 1001",
111                             0x04AD,           0x0A55,           0x0D25,           0x0E92,           0x0EC9,
112     //* 1368 -1372 */ "0110 1101 0100", "1010 1110 1010", "0101 0110 1011", "0100 1010 1011", "0110 1000 0101",
113                             0x06D4,           0x0ADA,           0x056B,           0x04AB,           0x0685,
114     //* 1373 -1377 */ "1011 0100 1001", "1011 1010 0100", "1011 1011 0010", "0101 1011 0101", "0010 1011 1010",
115                             0x0B49,           0x0BA4,           0x0BB2,           0x05B5,           0x02BA,
116     //* 1378 -1382 */ "1001 0101 1011", "0100 1010 1011", "0101 0101 0101", "0110 1011 0010", "0110 1101 1001",
117                             0x095B,           0x04AB,           0x0555,           0x06B2,           0x06D9,
118     //* 1383 -1387 */ "0010 1110 1100", "1001 0110 1110", "0100 1010 1110", "1010 0101 0110", "1101 0010 1010",
119                             0x02EC,           0x096E,           0x04AE,           0x0A56,           0x0D2A,
120     //* 1388 -1392 */ "1101 0101 0101", "0101 1010 1010", "1010 1011 0101", "0100 1011 1011", "0000 0101 1011",
121                             0x0D55,           0x05AA,           0x0AB5,           0x04BB,           0x005B,
122     //* 1393 -1397 */ "1001 0010 1011", "1010 1001 0101", "0011 0100 1010", "1011 1010 0101", "0101 1010 1010",
123                             0x092B,           0x0A95,           0x034A,           0x0BA5,           0x05AA,
124     //* 1398 -1402 */ "1010 1011 0101", "0101 0101 0110", "1010 1001 0110", "1101 0100 1010", "1110 1010 0101",
125                             0x0AB5,           0x0556,           0x0A96,           0x0B4A,           0x0EA5,
126     //* 1403 -1407 */ "0111 0101 0010", "0110 1110 1001", "0011 0110 1010", "1010 1010 1101", "0101 0101 0101",
127                             0x0752,           0x06E9,           0x036A,           0x0AAD,           0x0555,
128     //* 1408 -1412 */ "1010 1010 0101", "1011 0101 0010", "1011 1010 1001", "0101 1011 0100", "1001 1011 1010",
129                             0x0AA5,           0x0B52,           0x0BA9,           0x05B4,           0x09BA,
130     //* 1413 -1417 */ "0100 1101 1011", "0010 0101 1101", "0101 0010 1101", "1010 1010 0101", "1010 1101 0100",
131                             0x04DB,           0x025D,           0x052D,           0x0AA5,           0x0AD4,
132     //* 1418 -1422 */ "1010 1110 1010", "0101 0110 1101", "0100 1011 1101", "0010 0011 1101", "1001 0001 1101",
133                             0x0AEA,           0x056D,           0x04BD,           0x023D,           0x091D,
134     //* 1423 -1427 */ "1010 1001 0101", "1011 0100 1010", "1011 0101 1010", "0101 0110 1101", "0010 1011 0110",
135                             0x0A95,           0x0B4A,           0x0B5A,           0x056D,           0x02B6,
136     //* 1428 -1432 */ "1001 0011 1011", "0100 1001 1011", "0110 0101 0101", "0110 1010 1001", "0111 0101 0100",
137                             0x093B,           0x049B,           0x0655,           0x06A9,           0x0754,
138     //* 1433 -1437 */ "1011 0110 1010", "0101 0110 1100", "1010 1010 1101", "0101 0101 0101", "1011 0010 1001",
139                             0x0B6A,           0x056C,           0x0AAD,           0x0555,           0x0B29,
140     //* 1438 -1442 */ "1011 1001 0010", "1011 1010 1001", "0101 1101 0100", "1010 1101 1010", "0101 0101 1010",
141                             0x0B92,           0x0BA9,           0x05D4,           0x0ADA,           0x055A,
142     //* 1443 -1447 */ "1010 1010 1011", "0101 1001 0101", "0111 0100 1001", "0111 0110 0100", "1011 1010 1010",
143                             0x0AAB,           0x0595,           0x0749,           0x0764,           0x0BAA,
144     //* 1448 -1452 */ "0101 1011 0101", "0010 1011 0110", "1010 0101 0110", "1110 0100 1101", "1011 0010 0101",
145                             0x05B5,           0x02B6,           0x0A56,           0x0E4D,           0x0B25,
146     //* 1453 -1457 */ "1011 0101 0010", "1011 0110 1010", "0101 1010 1101", "0010 1010 1110", "1001 0010 1111",
147                             0x0B52,           0x0B6A,           0x05AD,           0x02AE,           0x092F,
148     //* 1458 -1462 */ "0100 1001 0111", "0110 0100 1011", "0110 1010 0101", "0110 1010 1100", "1010 1101 0110",
149                             0x0497,           0x064B,           0x06A5,           0x06AC,           0x0AD6,
150     //* 1463 -1467 */ "0101 0101 1101", "0100 1001 1101", "1010 0100 1101", "1101 0001 0110", "1101 1001 0101",
151                             0x055D,           0x049D,           0x0A4D,           0x0D16,           0x0D95,
152     //* 1468 -1472 */ "0101 1010 1010", "0101 1011 0101", "0010 1001 1010", "1001 0101 1011", "0100 1010 1100",
153                             0x05AA,           0x05B5,           0x029A,           0x095B,           0x04AC,
154     //* 1473 -1477 */ "0101 1001 0101", "0110 1100 1010", "0110 1110 0100", "1010 1110 1010", "0100 1111 0101",
155                             0x0595,           0x06CA,           0x06E4,           0x0AEA,           0x04F5,
156     //* 1478 -1480 */ "0010 1011 0110", "1001 0101 0110", "1010 1010 1010"
157                             0x02B6,           0x0956,           0x0AAA
158 };
159 
getUmalqura_MonthLength(int32_t y,int32_t m)160 int32_t getUmalqura_MonthLength(int32_t y, int32_t m) {
161     int32_t mask = (int32_t) (0x01 << (11 - m));    // set mask for bit corresponding to month
162     if((UMALQURA_MONTHLENGTH[y] & mask) == 0 )
163         return 29;
164     else
165         return 30;
166 
167 }
168 
169 //-------------------------------------------------------------------------
170 // Constructors...
171 //-------------------------------------------------------------------------
172 
getType() const173 const char *IslamicCalendar::getType() const {
174     const char *sType = NULL;
175 
176     switch (cType) {
177     case CIVIL:
178         sType = "islamic-civil";
179         break;
180     case ASTRONOMICAL:
181         sType = "islamic";
182         break;
183     case TBLA:
184         sType = "islamic-tbla";
185         break;
186     case UMALQURA:
187         sType = "islamic-umalqura";
188         break;
189     default:
190         U_ASSERT(false); // out of range
191         sType = "islamic";  // "islamic" is used as the generic type
192         break;
193     }
194     return sType;
195 }
196 
clone() const197 Calendar* IslamicCalendar::clone() const {
198     return new IslamicCalendar(*this);
199 }
200 
IslamicCalendar(const Locale & aLocale,UErrorCode & success,ECalculationType type)201 IslamicCalendar::IslamicCalendar(const Locale& aLocale, UErrorCode& success, ECalculationType type)
202 :   Calendar(TimeZone::createDefault(), aLocale, success),
203 cType(type)
204 {
205     setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
206 }
207 
IslamicCalendar(const IslamicCalendar & other)208 IslamicCalendar::IslamicCalendar(const IslamicCalendar& other) : Calendar(other), cType(other.cType) {
209 }
210 
~IslamicCalendar()211 IslamicCalendar::~IslamicCalendar()
212 {
213 }
214 
setCalculationType(ECalculationType type,UErrorCode & status)215 void IslamicCalendar::setCalculationType(ECalculationType type, UErrorCode &status)
216 {
217     if (cType != type) {
218         // The fields of the calendar will become invalid, because the calendar
219         // rules are different
220         UDate m = getTimeInMillis(status);
221         cType = type;
222         clear();
223         setTimeInMillis(m, status);
224     }
225 }
226 
227 /**
228 * Returns <code>true</code> if this object is using the fixed-cycle civil
229 * calendar, or <code>false</code> if using the religious, astronomical
230 * calendar.
231 * @draft ICU 2.4
232 */
isCivil()233 UBool IslamicCalendar::isCivil() {
234     return (cType == CIVIL);
235 }
236 
237 //-------------------------------------------------------------------------
238 // Minimum / Maximum access functions
239 //-------------------------------------------------------------------------
240 
241 // Note: Current IslamicCalendar implementation does not work
242 // well with negative years.
243 
244 // TODO: In some cases the current ICU Islamic calendar implementation shows
245 // a month as having 31 days. Since date parsing now uses range checks based
246 // on the table below, we need to change the range for last day of month to
247 // include 31 as a workaround until the implementation is fixed.
248 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
249     // Minimum  Greatest    Least  Maximum
250     //           Minimum  Maximum
251     {        0,        0,        0,        0}, // ERA
252     {        1,        1,  5000000,  5000000}, // YEAR
253     {        0,        0,       11,       11}, // MONTH
254     {        1,        1,       50,       51}, // WEEK_OF_YEAR
255     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
256     {        1,        1,       29,       31}, // DAY_OF_MONTH - 31 to workaround for cal implementation bug, should be 30
257     {        1,        1,      354,      355}, // DAY_OF_YEAR
258     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
259     {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
260     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
261     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
262     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
263     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
264     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
265     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
266     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
267     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
268     {        1,        1,  5000000,  5000000}, // YEAR_WOY
269     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
270     {        1,        1,  5000000,  5000000}, // EXTENDED_YEAR
271     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
272     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
273     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
274 };
275 
276 /**
277 * @draft ICU 2.4
278 */
handleGetLimit(UCalendarDateFields field,ELimitType limitType) const279 int32_t IslamicCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
280     return LIMITS[field][limitType];
281 }
282 
283 //-------------------------------------------------------------------------
284 // Assorted calculation utilities
285 //
286 
287 /**
288 * Determine whether a year is a leap year in the Islamic civil calendar
289 */
civilLeapYear(int32_t year)290 UBool IslamicCalendar::civilLeapYear(int32_t year)
291 {
292     return (14 + 11 * year) % 30 < 11;
293 }
294 
295 /**
296 * Return the day # on which the given year starts.  Days are counted
297 * from the Hijri epoch, origin 0.
298 */
yearStart(int32_t year) const299 int32_t IslamicCalendar::yearStart(int32_t year) const{
300     if (cType == CIVIL || cType == TBLA ||
301         (cType == UMALQURA && year < UMALQURA_YEAR_START))
302     {
303         return (year-1)*354 + ClockMath::floorDivide((3+11*year),30);
304     } else if(cType==ASTRONOMICAL){
305         return trueMonthStart(12*(year-1));
306     } else {
307         int32_t ys = yearStart(UMALQURA_YEAR_START-1);
308         ys+= handleGetYearLength(UMALQURA_YEAR_START-1);
309         for(int i=UMALQURA_YEAR_START; i< year; i++){
310             ys+= handleGetYearLength(i);
311         }
312         return ys;
313     }
314 }
315 
316 /**
317 * Return the day # on which the given month starts.  Days are counted
318 * from the Hijri epoch, origin 0.
319 *
320 * @param year  The hijri year
321 * @param year  The hijri month, 0-based
322 */
monthStart(int32_t year,int32_t month) const323 int32_t IslamicCalendar::monthStart(int32_t year, int32_t month) const {
324     if (cType == CIVIL || cType == TBLA) {
325         return (int32_t)uprv_ceil(29.5*month)
326             + (year-1)*354 + (int32_t)ClockMath::floorDivide((3+11*year),30);
327     } else if(cType==ASTRONOMICAL){
328         return trueMonthStart(12*(year-1) + month);
329     } else {
330         int32_t ms = yearStart(year);
331         for(int i=0; i< month; i++){
332             ms+= handleGetMonthLength(year, i);
333         }
334         return ms;
335     }
336 }
337 
338 /**
339 * Find the day number on which a particular month of the true/lunar
340 * Islamic calendar starts.
341 *
342 * @param month The month in question, origin 0 from the Hijri epoch
343 *
344 * @return The day number on which the given month starts.
345 */
trueMonthStart(int32_t month) const346 int32_t IslamicCalendar::trueMonthStart(int32_t month) const
347 {
348     UErrorCode status = U_ZERO_ERROR;
349     int32_t start = CalendarCache::get(&gMonthCache, month, status);
350 
351     if (start==0) {
352         // Make a guess at when the month started, using the average length
353         UDate origin = HIJRA_MILLIS
354             + uprv_floor(month * CalendarAstronomer::SYNODIC_MONTH) * kOneDay;
355 
356         // moonAge will fail due to memory allocation error
357         double age = moonAge(origin, status);
358         if (U_FAILURE(status)) {
359             goto trueMonthStartEnd;
360         }
361 
362         if (age >= 0) {
363             // The month has already started
364             do {
365                 origin -= kOneDay;
366                 age = moonAge(origin, status);
367                 if (U_FAILURE(status)) {
368                     goto trueMonthStartEnd;
369                 }
370             } while (age >= 0);
371         }
372         else {
373             // Preceding month has not ended yet.
374             do {
375                 origin += kOneDay;
376                 age = moonAge(origin, status);
377                 if (U_FAILURE(status)) {
378                     goto trueMonthStartEnd;
379                 }
380             } while (age < 0);
381         }
382         start = (int32_t)ClockMath::floorDivide((origin - HIJRA_MILLIS), (double)kOneDay) + 1;
383         CalendarCache::put(&gMonthCache, month, start, status);
384     }
385 trueMonthStartEnd :
386     if(U_FAILURE(status)) {
387         start = 0;
388     }
389     return start;
390 }
391 
392 /**
393 * Return the "age" of the moon at the given time; this is the difference
394 * in ecliptic latitude between the moon and the sun.  This method simply
395 * calls CalendarAstronomer.moonAge, converts to degrees,
396 * and adjusts the result to be in the range [-180, 180].
397 *
398 * @param time  The time at which the moon's age is desired,
399 *              in millis since 1/1/1970.
400 */
moonAge(UDate time,UErrorCode & status)401 double IslamicCalendar::moonAge(UDate time, UErrorCode &status)
402 {
403     double age = 0;
404 
405     umtx_lock(&astroLock);
406     if(gIslamicCalendarAstro == NULL) {
407         gIslamicCalendarAstro = new CalendarAstronomer();
408         if (gIslamicCalendarAstro == NULL) {
409             status = U_MEMORY_ALLOCATION_ERROR;
410             return age;
411         }
412         ucln_i18n_registerCleanup(UCLN_I18N_ISLAMIC_CALENDAR, calendar_islamic_cleanup);
413     }
414     gIslamicCalendarAstro->setTime(time);
415     age = gIslamicCalendarAstro->getMoonAge();
416     umtx_unlock(&astroLock);
417 
418     // Convert to degrees and normalize...
419     age = age * 180 / CalendarAstronomer::PI;
420     if (age > 180) {
421         age = age - 360;
422     }
423 
424     return age;
425 }
426 
427 //----------------------------------------------------------------------
428 // Calendar framework
429 //----------------------------------------------------------------------
430 
431 /**
432 * Return the length (in days) of the given month.
433 *
434 * @param year  The hijri year
435 * @param year  The hijri month, 0-based
436 * @draft ICU 2.4
437 */
handleGetMonthLength(int32_t extendedYear,int32_t month) const438 int32_t IslamicCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
439 
440     int32_t length = 0;
441 
442     if (cType == CIVIL || cType == TBLA ||
443         (cType == UMALQURA && (extendedYear<UMALQURA_YEAR_START || extendedYear>UMALQURA_YEAR_END)) ) {
444         length = 29 + (month+1) % 2;
445         if (month == DHU_AL_HIJJAH && civilLeapYear(extendedYear)) {
446             length++;
447         }
448     } else if(cType == ASTRONOMICAL){
449         month = 12*(extendedYear-1) + month;
450         length =  trueMonthStart(month+1) - trueMonthStart(month) ;
451     } else {
452         length = getUmalqura_MonthLength(extendedYear - UMALQURA_YEAR_START, month);
453     }
454     return length;
455 }
456 
457 /**
458 * Return the number of days in the given Islamic year
459 * @draft ICU 2.4
460 */
handleGetYearLength(int32_t extendedYear) const461 int32_t IslamicCalendar::handleGetYearLength(int32_t extendedYear) const {
462     if (cType == CIVIL || cType == TBLA ||
463         (cType == UMALQURA && (extendedYear<UMALQURA_YEAR_START || extendedYear>UMALQURA_YEAR_END)) ) {
464         return 354 + (civilLeapYear(extendedYear) ? 1 : 0);
465     } else if(cType == ASTRONOMICAL){
466         int32_t month = 12*(extendedYear-1);
467         return (trueMonthStart(month + 12) - trueMonthStart(month));
468     } else {
469         int len = 0;
470         for(int i=0; i<12; i++)
471             len += handleGetMonthLength(extendedYear, i);
472         return len;
473     }
474 }
475 
476 //-------------------------------------------------------------------------
477 // Functions for converting from field values to milliseconds....
478 //-------------------------------------------------------------------------
479 
480 // Return JD of start of given month/year
481 /**
482 * @draft ICU 2.4
483 */
handleComputeMonthStart(int32_t eyear,int32_t month,UBool) const484 int32_t IslamicCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */) const {
485     return monthStart(eyear, month) + 1948439;
486 }
487 
488 //-------------------------------------------------------------------------
489 // Functions for converting from milliseconds to field values
490 //-------------------------------------------------------------------------
491 
492 /**
493 * @draft ICU 2.4
494 */
handleGetExtendedYear()495 int32_t IslamicCalendar::handleGetExtendedYear() {
496     int32_t year;
497     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
498         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
499     } else {
500         year = internalGet(UCAL_YEAR, 1); // Default to year 1
501     }
502     return year;
503 }
504 
505 /**
506 * Override Calendar to compute several fields specific to the Islamic
507 * calendar system.  These are:
508 *
509 * <ul><li>ERA
510 * <li>YEAR
511 * <li>MONTH
512 * <li>DAY_OF_MONTH
513 * <li>DAY_OF_YEAR
514 * <li>EXTENDED_YEAR</ul>
515 *
516 * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
517 * method is called. The getGregorianXxx() methods return Gregorian
518 * calendar equivalents for the given Julian day.
519 * @draft ICU 2.4
520 */
handleComputeFields(int32_t julianDay,UErrorCode & status)521 void IslamicCalendar::handleComputeFields(int32_t julianDay, UErrorCode &status) {
522     int32_t year, month, dayOfMonth, dayOfYear;
523     UDate startDate;
524     int32_t days = julianDay - CIVIL_EPOC;
525 
526     if (cType == CIVIL || cType == TBLA) {
527         if(cType == TBLA)
528             days = julianDay - ASTRONOMICAL_EPOC;
529         // Use the civil calendar approximation, which is just arithmetic
530         year  = (int)ClockMath::floorDivide( (double)(30 * days + 10646) , 10631.0 );
531         month = (int32_t)uprv_ceil((days - 29 - yearStart(year)) / 29.5 );
532         month = month<11?month:11;
533         startDate = monthStart(year, month);
534     } else if(cType == ASTRONOMICAL){
535         // Guess at the number of elapsed full months since the epoch
536         int32_t months = (int32_t)uprv_floor((double)days / CalendarAstronomer::SYNODIC_MONTH);
537 
538         startDate = uprv_floor(months * CalendarAstronomer::SYNODIC_MONTH);
539 
540         double age = moonAge(internalGetTime(), status);
541         if (U_FAILURE(status)) {
542             status = U_MEMORY_ALLOCATION_ERROR;
543             return;
544         }
545         if ( days - startDate >= 25 && age > 0) {
546             // If we're near the end of the month, assume next month and search backwards
547             months++;
548         }
549 
550         // Find out the last time that the new moon was actually visible at this longitude
551         // This returns midnight the night that the moon was visible at sunset.
552         while ((startDate = trueMonthStart(months)) > days) {
553             // If it was after the date in question, back up a month and try again
554             months--;
555         }
556 
557         year = months / 12 + 1;
558         month = months % 12;
559     } else if(cType == UMALQURA) {
560         int32_t umalquraStartdays = yearStart(UMALQURA_YEAR_START) ;
561         if( days < umalquraStartdays){
562                 //Use Civil calculation
563                 year  = (int)ClockMath::floorDivide( (double)(30 * days + 10646) , 10631.0 );
564                 month = (int32_t)uprv_ceil((days - 29 - yearStart(year)) / 29.5 );
565                 month = month<11?month:11;
566                 startDate = monthStart(year, month);
567             }else{
568                 int y =UMALQURA_YEAR_START-1, m =0;
569                 long d = 1;
570                 while(d > 0){
571                     y++;
572                     d = days - yearStart(y) +1;
573                     if(d == handleGetYearLength(y)){
574                         m=11;
575                         break;
576                     }else if(d < handleGetYearLength(y) ){
577                         int monthLen = handleGetMonthLength(y, m);
578                         m=0;
579                         while(d > monthLen){
580                             d -= monthLen;
581                             m++;
582                             monthLen = handleGetMonthLength(y, m);
583                         }
584                         break;
585                     }
586                 }
587                 year = y;
588                 month = m;
589             }
590     } else { // invalid 'civil'
591       U_ASSERT(false); // should not get here, out of range
592       year=month=0;
593     }
594 
595     dayOfMonth = (days - monthStart(year, month)) + 1;
596 
597     // Now figure out the day of the year.
598     dayOfYear = (days - monthStart(year, 0) + 1);
599 
600 
601     internalSet(UCAL_ERA, 0);
602     internalSet(UCAL_YEAR, year);
603     internalSet(UCAL_EXTENDED_YEAR, year);
604     internalSet(UCAL_MONTH, month);
605     internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
606     internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
607 }
608 
609 UBool
inDaylightTime(UErrorCode & status) const610 IslamicCalendar::inDaylightTime(UErrorCode& status) const
611 {
612     // copied from GregorianCalendar
613     if (U_FAILURE(status) || (&(getTimeZone()) == NULL && !getTimeZone().useDaylightTime()))
614         return FALSE;
615 
616     // Force an update of the state of the Calendar.
617     ((IslamicCalendar*)this)->complete(status); // cast away const
618 
619     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
620 }
621 
622 /**
623  * The system maintains a static default century start date and Year.  They are
624  * initialized the first time they are used.  Once the system default century date
625  * and year are set, they do not change.
626  */
627 static UDate           gSystemDefaultCenturyStart       = DBL_MIN;
628 static int32_t         gSystemDefaultCenturyStartYear   = -1;
629 static icu::UInitOnce  gSystemDefaultCenturyInit        = U_INITONCE_INITIALIZER;
630 
631 
haveDefaultCentury() const632 UBool IslamicCalendar::haveDefaultCentury() const
633 {
634     return TRUE;
635 }
636 
defaultCenturyStart() const637 UDate IslamicCalendar::defaultCenturyStart() const
638 {
639     // lazy-evaluate systemDefaultCenturyStart
640     umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
641     return gSystemDefaultCenturyStart;
642 }
643 
defaultCenturyStartYear() const644 int32_t IslamicCalendar::defaultCenturyStartYear() const
645 {
646     // lazy-evaluate systemDefaultCenturyStartYear
647     umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
648     return gSystemDefaultCenturyStartYear;
649 }
650 
651 
652 void U_CALLCONV
initializeSystemDefaultCentury()653 IslamicCalendar::initializeSystemDefaultCentury()
654 {
655     // initialize systemDefaultCentury and systemDefaultCenturyYear based
656     // on the current time.  They'll be set to 80 years before
657     // the current time.
658     UErrorCode status = U_ZERO_ERROR;
659     IslamicCalendar calendar(Locale("@calendar=islamic-civil"),status);
660     if (U_SUCCESS(status)) {
661         calendar.setTime(Calendar::getNow(), status);
662         calendar.add(UCAL_YEAR, -80, status);
663 
664         gSystemDefaultCenturyStart = calendar.getTime(status);
665         gSystemDefaultCenturyStartYear = calendar.get(UCAL_YEAR, status);
666     }
667     // We have no recourse upon failure unless we want to propagate the failure
668     // out.
669 }
670 
671 
672 
673 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IslamicCalendar)
674 
675 U_NAMESPACE_END
676 
677 #endif
678 
679