Home | History | Annotate | Download | only in i18n 
      1 /*
      2 ******************************************************************************
      3 * Copyright (C) 2003-2010, 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>
     33 static void debug_islamcal_loc(const char *f, int32_t l)
     34 {
     35     fprintf(stderr, "%s:%d: ", f, l);
     36 }
     37 
     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
     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 
     81 const char *IslamicCalendar::getType() const {
     82     if(civil==CIVIL) {
     83         return "islamic-civil";
     84     } else {
     85         return "islamic";
     86     }
     87 }
     88 
     89 Calendar* IslamicCalendar::clone() const {
     90     return new IslamicCalendar(*this);
     91 }
     92 
     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 
    100 IslamicCalendar::IslamicCalendar(const IslamicCalendar& other) : Calendar(other), civil(other.civil) {
    101 }
    102 
    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 */
    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 */
    133 UBool IslamicCalendar::isCivil() {
    134     return (civil == CIVIL);
    135 }
    136 
    137 //-------------------------------------------------------------------------
    138 // Minimum / Maximum access functions
    139 //-------------------------------------------------------------------------
    140 
    141 // Note: Current IslamicCalendar implementation does not work
    142 // well with negative years.
    143 
    144 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
    145     // Minimum  Greatest    Least  Maximum
    146     //           Minimum  Maximum
    147     {        0,        0,        0,        0}, // ERA
    148     {        1,        1,  5000000,  5000000}, // YEAR
    149     {        0,        0,       11,       11}, // MONTH
    150     {        1,        1,       50,       51}, // WEEK_OF_YEAR
    151     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
    152     {        1,        1,       29,       30}, // DAY_OF_MONTH
    153     {        1,        1,      354,      355}, // DAY_OF_YEAR
    154     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
    155     {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
    156     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
    157     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
    158     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
    159     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
    160     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
    161     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
    162     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
    163     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
    164     {        1,        1,  5000000,  5000000}, // YEAR_WOY
    165     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
    166     {        1,        1,  5000000,  5000000}, // EXTENDED_YEAR
    167     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
    168     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
    169     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
    170 };
    171 
    172 /**
    173 * @draft ICU 2.4
    174 */
    175 int32_t IslamicCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
    176     return LIMITS[field][limitType];
    177 }
    178 
    179 //-------------------------------------------------------------------------
    180 // Assorted calculation utilities
    181 //
    182 
    183 /**
    184 * Determine whether a year is a leap year in the Islamic civil calendar
    185 */
    186 UBool IslamicCalendar::civilLeapYear(int32_t year)
    187 {
    188     return (14 + 11 * year) % 30 < 11;
    189 }
    190 
    191 /**
    192 * Return the day # on which the given year starts.  Days are counted
    193 * from the Hijri epoch, origin 0.
    194 */
    195 int32_t IslamicCalendar::yearStart(int32_t year) {
    196     if (civil == CIVIL) {
    197         return (year-1)*354 + ClockMath::floorDivide((3+11*year),30);
    198     } else {
    199         return trueMonthStart(12*(year-1));
    200     }
    201 }
    202 
    203 /**
    204 * Return the day # on which the given month starts.  Days are counted
    205 * from the Hijri epoch, origin 0.
    206 *
    207 * @param year  The hijri year
    208 * @param year  The hijri month, 0-based
    209 */
    210 int32_t IslamicCalendar::monthStart(int32_t year, int32_t month) const {
    211     if (civil == CIVIL) {
    212         return (int32_t)uprv_ceil(29.5*month)
    213             + (year-1)*354 + (int32_t)ClockMath::floorDivide((3+11*year),30);
    214     } else {
    215         return trueMonthStart(12*(year-1) + month);
    216     }
    217 }
    218 
    219 /**
    220 * Find the day number on which a particular month of the true/lunar
    221 * Islamic calendar starts.
    222 *
    223 * @param month The month in question, origin 0 from the Hijri epoch
    224 *
    225 * @return The day number on which the given month starts.
    226 */
    227 int32_t IslamicCalendar::trueMonthStart(int32_t month) const
    228 {
    229     UErrorCode status = U_ZERO_ERROR;
    230     int32_t start = CalendarCache::get(&gMonthCache, month, status);
    231 
    232     if (start==0) {
    233         // Make a guess at when the month started, using the average length
    234         UDate origin = HIJRA_MILLIS
    235             + uprv_floor(month * CalendarAstronomer::SYNODIC_MONTH) * kOneDay;
    236 
    237         // moonAge will fail due to memory allocation error
    238         double age = moonAge(origin, status);
    239         if (U_FAILURE(status)) {
    240             goto trueMonthStartEnd;
    241         }
    242 
    243         if (age >= 0) {
    244             // The month has already started
    245             do {
    246                 origin -= kOneDay;
    247                 age = moonAge(origin, status);
    248                 if (U_FAILURE(status)) {
    249                     goto trueMonthStartEnd;
    250                 }
    251             } while (age >= 0);
    252         }
    253         else {
    254             // Preceding month has not ended yet.
    255             do {
    256                 origin += kOneDay;
    257                 age = moonAge(origin, status);
    258                 if (U_FAILURE(status)) {
    259                     goto trueMonthStartEnd;
    260                 }
    261             } while (age < 0);
    262         }
    263         start = (int32_t)ClockMath::floorDivide((origin - HIJRA_MILLIS), (double)kOneDay) + 1;
    264         CalendarCache::put(&gMonthCache, month, start, status);
    265     }
    266 trueMonthStartEnd :
    267     if(U_FAILURE(status)) {
    268         start = 0;
    269     }
    270     return start;
    271 }
    272 
    273 /**
    274 * Return the "age" of the moon at the given time; this is the difference
    275 * in ecliptic latitude between the moon and the sun.  This method simply
    276 * calls CalendarAstronomer.moonAge, converts to degrees,
    277 * and adjusts the result to be in the range [-180, 180].
    278 *
    279 * @param time  The time at which the moon's age is desired,
    280 *              in millis since 1/1/1970.
    281 */
    282 double IslamicCalendar::moonAge(UDate time, UErrorCode &status)
    283 {
    284     double age = 0;
    285 
    286     umtx_lock(&astroLock);
    287     if(gIslamicCalendarAstro == NULL) {
    288         gIslamicCalendarAstro = new CalendarAstronomer();
    289         if (gIslamicCalendarAstro == NULL) {
    290             status = U_MEMORY_ALLOCATION_ERROR;
    291             return age;
    292         }
    293         ucln_i18n_registerCleanup(UCLN_I18N_ISLAMIC_CALENDAR, calendar_islamic_cleanup);
    294     }
    295     gIslamicCalendarAstro->setTime(time);
    296     age = gIslamicCalendarAstro->getMoonAge();
    297     umtx_unlock(&astroLock);
    298 
    299     // Convert to degrees and normalize...
    300     age = age * 180 / CalendarAstronomer::PI;
    301     if (age > 180) {
    302         age = age - 360;
    303     }
    304 
    305     return age;
    306 }
    307 
    308 //----------------------------------------------------------------------
    309 // Calendar framework
    310 //----------------------------------------------------------------------
    311 
    312 /**
    313 * Return the length (in days) of the given month.
    314 *
    315 * @param year  The hijri year
    316 * @param year  The hijri month, 0-based
    317 * @draft ICU 2.4
    318 */
    319 int32_t IslamicCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
    320 
    321     int32_t length = 0;
    322 
    323     if (civil == CIVIL) {
    324         length = 29 + (month+1) % 2;
    325         if (month == DHU_AL_HIJJAH && civilLeapYear(extendedYear)) {
    326             length++;
    327         }
    328     } else {
    329         month = 12*(extendedYear-1) + month;
    330         length =  trueMonthStart(month+1) - trueMonthStart(month) ;
    331     }
    332     return length;
    333 }
    334 
    335 /**
    336 * Return the number of days in the given Islamic year
    337 * @draft ICU 2.4
    338 */
    339 int32_t IslamicCalendar::handleGetYearLength(int32_t extendedYear) const {
    340     if (civil == CIVIL) {
    341         return 354 + (civilLeapYear(extendedYear) ? 1 : 0);
    342     } else {
    343         int32_t month = 12*(extendedYear-1);
    344         return (trueMonthStart(month + 12) - trueMonthStart(month));
    345     }
    346 }
    347 
    348 //-------------------------------------------------------------------------
    349 // Functions for converting from field values to milliseconds....
    350 //-------------------------------------------------------------------------
    351 
    352 // Return JD of start of given month/year
    353 /**
    354 * @draft ICU 2.4
    355 */
    356 int32_t IslamicCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */) const {
    357     return monthStart(eyear, month) + 1948439;
    358 }
    359 
    360 //-------------------------------------------------------------------------
    361 // Functions for converting from milliseconds to field values
    362 //-------------------------------------------------------------------------
    363 
    364 /**
    365 * @draft ICU 2.4
    366 */
    367 int32_t IslamicCalendar::handleGetExtendedYear() {
    368     int32_t year;
    369     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
    370         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
    371     } else {
    372         year = internalGet(UCAL_YEAR, 1); // Default to year 1
    373     }
    374     return year;
    375 }
    376 
    377 /**
    378 * Override Calendar to compute several fields specific to the Islamic
    379 * calendar system.  These are:
    380 *
    381 * <ul><li>ERA
    382 * <li>YEAR
    383 * <li>MONTH
    384 * <li>DAY_OF_MONTH
    385 * <li>DAY_OF_YEAR
    386 * <li>EXTENDED_YEAR</ul>
    387 *
    388 * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
    389 * method is called. The getGregorianXxx() methods return Gregorian
    390 * calendar equivalents for the given Julian day.
    391 * @draft ICU 2.4
    392 */
    393 void IslamicCalendar::handleComputeFields(int32_t julianDay, UErrorCode &status) {
    394     int32_t year, month, dayOfMonth, dayOfYear;
    395     UDate startDate;
    396     int32_t days = julianDay - 1948440;
    397 
    398     if (civil == CIVIL) {
    399         // Use the civil calendar approximation, which is just arithmetic
    400         year  = (int)ClockMath::floorDivide( (double)(30 * days + 10646) , 10631.0 );
    401         month = (int32_t)uprv_ceil((days - 29 - yearStart(year)) / 29.5 );
    402         month = month<11?month:11;
    403         startDate = monthStart(year, month);
    404     } else {
    405         // Guess at the number of elapsed full months since the epoch
    406         int32_t months = (int32_t)uprv_floor((double)days / CalendarAstronomer::SYNODIC_MONTH);
    407 
    408         startDate = uprv_floor(months * CalendarAstronomer::SYNODIC_MONTH);
    409 
    410         double age = moonAge(internalGetTime(), status);
    411         if (U_FAILURE(status)) {
    412         	status = U_MEMORY_ALLOCATION_ERROR;
    413         	return;
    414         }
    415         if ( days - startDate >= 25 && age > 0) {
    416             // If we're near the end of the month, assume next month and search backwards
    417             months++;
    418         }
    419 
    420         // Find out the last time that the new moon was actually visible at this longitude
    421         // This returns midnight the night that the moon was visible at sunset.
    422         while ((startDate = trueMonthStart(months)) > days) {
    423             // If it was after the date in question, back up a month and try again
    424             months--;
    425         }
    426 
    427         year = months / 12 + 1;
    428         month = months % 12;
    429     }
    430 
    431     dayOfMonth = (days - monthStart(year, month)) + 1;
    432 
    433     // Now figure out the day of the year.
    434     dayOfYear = (days - monthStart(year, 0) + 1);
    435 
    436     internalSet(UCAL_ERA, 0);
    437     internalSet(UCAL_YEAR, year);
    438     internalSet(UCAL_EXTENDED_YEAR, year);
    439     internalSet(UCAL_MONTH, month);
    440     internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
    441     internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
    442 }
    443 
    444 UBool
    445 IslamicCalendar::inDaylightTime(UErrorCode& status) const
    446 {
    447     // copied from GregorianCalendar
    448     if (U_FAILURE(status) || (&(getTimeZone()) == NULL && !getTimeZone().useDaylightTime()))
    449         return FALSE;
    450 
    451     // Force an update of the state of the Calendar.
    452     ((IslamicCalendar*)this)->complete(status); // cast away const
    453 
    454     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
    455 }
    456 
    457 // default century
    458 const UDate     IslamicCalendar::fgSystemDefaultCentury        = DBL_MIN;
    459 const int32_t   IslamicCalendar::fgSystemDefaultCenturyYear    = -1;
    460 
    461 UDate           IslamicCalendar::fgSystemDefaultCenturyStart       = DBL_MIN;
    462 int32_t         IslamicCalendar::fgSystemDefaultCenturyStartYear   = -1;
    463 
    464 
    465 UBool IslamicCalendar::haveDefaultCentury() const
    466 {
    467     return TRUE;
    468 }
    469 
    470 UDate IslamicCalendar::defaultCenturyStart() const
    471 {
    472     return internalGetDefaultCenturyStart();
    473 }
    474 
    475 int32_t IslamicCalendar::defaultCenturyStartYear() const
    476 {
    477     return internalGetDefaultCenturyStartYear();
    478 }
    479 
    480 UDate
    481 IslamicCalendar::internalGetDefaultCenturyStart() const
    482 {
    483     // lazy-evaluate systemDefaultCenturyStart
    484     UBool needsUpdate;
    485     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
    486 
    487     if (needsUpdate) {
    488         initializeSystemDefaultCentury();
    489     }
    490 
    491     // use defaultCenturyStart unless it's the flag value;
    492     // then use systemDefaultCenturyStart
    493 
    494     return fgSystemDefaultCenturyStart;
    495 }
    496 
    497 int32_t
    498 IslamicCalendar::internalGetDefaultCenturyStartYear() const
    499 {
    500     // lazy-evaluate systemDefaultCenturyStartYear
    501     UBool needsUpdate;
    502     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
    503 
    504     if (needsUpdate) {
    505         initializeSystemDefaultCentury();
    506     }
    507 
    508     // use defaultCenturyStart unless it's the flag value;
    509     // then use systemDefaultCenturyStartYear
    510 
    511     return    fgSystemDefaultCenturyStartYear;
    512 }
    513 
    514 void
    515 IslamicCalendar::initializeSystemDefaultCentury()
    516 {
    517     // initialize systemDefaultCentury and systemDefaultCenturyYear based
    518     // on the current time.  They'll be set to 80 years before
    519     // the current time.
    520     UErrorCode status = U_ZERO_ERROR;
    521     IslamicCalendar calendar(Locale("@calendar=islamic-civil"),status);
    522     if (U_SUCCESS(status))
    523     {
    524         calendar.setTime(Calendar::getNow(), status);
    525         calendar.add(UCAL_YEAR, -80, status);
    526         UDate    newStart =  calendar.getTime(status);
    527         int32_t  newYear  =  calendar.get(UCAL_YEAR, status);
    528         umtx_lock(NULL);
    529         if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury)
    530         {
    531             fgSystemDefaultCenturyStartYear = newYear;
    532             fgSystemDefaultCenturyStart = newStart;
    533         }
    534         umtx_unlock(NULL);
    535     }
    536     // We have no recourse upon failure unless we want to propagate the failure
    537     // out.
    538 }
    539 
    540 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IslamicCalendar)
    541 
    542 U_NAMESPACE_END
    543 
    544 #endif
    545 
    546