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      1 /*
      2 ******************************************************************************
      3 * Copyright (C) 2003-2011, 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 // TODO: In some cases the current ICU Islamic calendar implementation shows
    145 // a month as having 31 days. Since date parsing now uses range checks based
    146 // on the table below, we need to change the range for last day of month to
    147 // include 31 as a workaround until the implementation is fixed.
    148 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
    149     // Minimum  Greatest    Least  Maximum
    150     //           Minimum  Maximum
    151     {        0,        0,        0,        0}, // ERA
    152     {        1,        1,  5000000,  5000000}, // YEAR
    153     {        0,        0,       11,       11}, // MONTH
    154     {        1,        1,       50,       51}, // WEEK_OF_YEAR
    155     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
    156     {        1,        1,       29,       31}, // DAY_OF_MONTH - 31 to workaround for cal implementation bug, should be 30
    157     {        1,        1,      354,      355}, // DAY_OF_YEAR
    158     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
    159     {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
    160     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
    161     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
    162     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
    163     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
    164     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
    165     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
    166     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
    167     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
    168     {        1,        1,  5000000,  5000000}, // YEAR_WOY
    169     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
    170     {        1,        1,  5000000,  5000000}, // EXTENDED_YEAR
    171     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
    172     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
    173     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
    174 };
    175 
    176 /**
    177 * @draft ICU 2.4
    178 */
    179 int32_t IslamicCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
    180     return LIMITS[field][limitType];
    181 }
    182 
    183 //-------------------------------------------------------------------------
    184 // Assorted calculation utilities
    185 //
    186 
    187 /**
    188 * Determine whether a year is a leap year in the Islamic civil calendar
    189 */
    190 UBool IslamicCalendar::civilLeapYear(int32_t year)
    191 {
    192     return (14 + 11 * year) % 30 < 11;
    193 }
    194 
    195 /**
    196 * Return the day # on which the given year starts.  Days are counted
    197 * from the Hijri epoch, origin 0.
    198 */
    199 int32_t IslamicCalendar::yearStart(int32_t year) {
    200     if (civil == CIVIL) {
    201         return (year-1)*354 + ClockMath::floorDivide((3+11*year),30);
    202     } else {
    203         return trueMonthStart(12*(year-1));
    204     }
    205 }
    206 
    207 /**
    208 * Return the day # on which the given month starts.  Days are counted
    209 * from the Hijri epoch, origin 0.
    210 *
    211 * @param year  The hijri year
    212 * @param year  The hijri month, 0-based
    213 */
    214 int32_t IslamicCalendar::monthStart(int32_t year, int32_t month) const {
    215     if (civil == CIVIL) {
    216         return (int32_t)uprv_ceil(29.5*month)
    217             + (year-1)*354 + (int32_t)ClockMath::floorDivide((3+11*year),30);
    218     } else {
    219         return trueMonthStart(12*(year-1) + month);
    220     }
    221 }
    222 
    223 /**
    224 * Find the day number on which a particular month of the true/lunar
    225 * Islamic calendar starts.
    226 *
    227 * @param month The month in question, origin 0 from the Hijri epoch
    228 *
    229 * @return The day number on which the given month starts.
    230 */
    231 int32_t IslamicCalendar::trueMonthStart(int32_t month) const
    232 {
    233     UErrorCode status = U_ZERO_ERROR;
    234     int32_t start = CalendarCache::get(&gMonthCache, month, status);
    235 
    236     if (start==0) {
    237         // Make a guess at when the month started, using the average length
    238         UDate origin = HIJRA_MILLIS
    239             + uprv_floor(month * CalendarAstronomer::SYNODIC_MONTH) * kOneDay;
    240 
    241         // moonAge will fail due to memory allocation error
    242         double age = moonAge(origin, status);
    243         if (U_FAILURE(status)) {
    244             goto trueMonthStartEnd;
    245         }
    246 
    247         if (age >= 0) {
    248             // The month has already started
    249             do {
    250                 origin -= kOneDay;
    251                 age = moonAge(origin, status);
    252                 if (U_FAILURE(status)) {
    253                     goto trueMonthStartEnd;
    254                 }
    255             } while (age >= 0);
    256         }
    257         else {
    258             // Preceding month has not ended yet.
    259             do {
    260                 origin += kOneDay;
    261                 age = moonAge(origin, status);
    262                 if (U_FAILURE(status)) {
    263                     goto trueMonthStartEnd;
    264                 }
    265             } while (age < 0);
    266         }
    267         start = (int32_t)ClockMath::floorDivide((origin - HIJRA_MILLIS), (double)kOneDay) + 1;
    268         CalendarCache::put(&gMonthCache, month, start, status);
    269     }
    270 trueMonthStartEnd :
    271     if(U_FAILURE(status)) {
    272         start = 0;
    273     }
    274     return start;
    275 }
    276 
    277 /**
    278 * Return the "age" of the moon at the given time; this is the difference
    279 * in ecliptic latitude between the moon and the sun.  This method simply
    280 * calls CalendarAstronomer.moonAge, converts to degrees,
    281 * and adjusts the result to be in the range [-180, 180].
    282 *
    283 * @param time  The time at which the moon's age is desired,
    284 *              in millis since 1/1/1970.
    285 */
    286 double IslamicCalendar::moonAge(UDate time, UErrorCode &status)
    287 {
    288     double age = 0;
    289 
    290     umtx_lock(&astroLock);
    291     if(gIslamicCalendarAstro == NULL) {
    292         gIslamicCalendarAstro = new CalendarAstronomer();
    293         if (gIslamicCalendarAstro == NULL) {
    294             status = U_MEMORY_ALLOCATION_ERROR;
    295             return age;
    296         }
    297         ucln_i18n_registerCleanup(UCLN_I18N_ISLAMIC_CALENDAR, calendar_islamic_cleanup);
    298     }
    299     gIslamicCalendarAstro->setTime(time);
    300     age = gIslamicCalendarAstro->getMoonAge();
    301     umtx_unlock(&astroLock);
    302 
    303     // Convert to degrees and normalize...
    304     age = age * 180 / CalendarAstronomer::PI;
    305     if (age > 180) {
    306         age = age - 360;
    307     }
    308 
    309     return age;
    310 }
    311 
    312 //----------------------------------------------------------------------
    313 // Calendar framework
    314 //----------------------------------------------------------------------
    315 
    316 /**
    317 * Return the length (in days) of the given month.
    318 *
    319 * @param year  The hijri year
    320 * @param year  The hijri month, 0-based
    321 * @draft ICU 2.4
    322 */
    323 int32_t IslamicCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
    324 
    325     int32_t length = 0;
    326 
    327     if (civil == CIVIL) {
    328         length = 29 + (month+1) % 2;
    329         if (month == DHU_AL_HIJJAH && civilLeapYear(extendedYear)) {
    330             length++;
    331         }
    332     } else {
    333         month = 12*(extendedYear-1) + month;
    334         length =  trueMonthStart(month+1) - trueMonthStart(month) ;
    335     }
    336     return length;
    337 }
    338 
    339 /**
    340 * Return the number of days in the given Islamic year
    341 * @draft ICU 2.4
    342 */
    343 int32_t IslamicCalendar::handleGetYearLength(int32_t extendedYear) const {
    344     if (civil == CIVIL) {
    345         return 354 + (civilLeapYear(extendedYear) ? 1 : 0);
    346     } else {
    347         int32_t month = 12*(extendedYear-1);
    348         return (trueMonthStart(month + 12) - trueMonthStart(month));
    349     }
    350 }
    351 
    352 //-------------------------------------------------------------------------
    353 // Functions for converting from field values to milliseconds....
    354 //-------------------------------------------------------------------------
    355 
    356 // Return JD of start of given month/year
    357 /**
    358 * @draft ICU 2.4
    359 */
    360 int32_t IslamicCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */) const {
    361     return monthStart(eyear, month) + 1948439;
    362 }
    363 
    364 //-------------------------------------------------------------------------
    365 // Functions for converting from milliseconds to field values
    366 //-------------------------------------------------------------------------
    367 
    368 /**
    369 * @draft ICU 2.4
    370 */
    371 int32_t IslamicCalendar::handleGetExtendedYear() {
    372     int32_t year;
    373     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
    374         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
    375     } else {
    376         year = internalGet(UCAL_YEAR, 1); // Default to year 1
    377     }
    378     return year;
    379 }
    380 
    381 /**
    382 * Override Calendar to compute several fields specific to the Islamic
    383 * calendar system.  These are:
    384 *
    385 * <ul><li>ERA
    386 * <li>YEAR
    387 * <li>MONTH
    388 * <li>DAY_OF_MONTH
    389 * <li>DAY_OF_YEAR
    390 * <li>EXTENDED_YEAR</ul>
    391 *
    392 * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
    393 * method is called. The getGregorianXxx() methods return Gregorian
    394 * calendar equivalents for the given Julian day.
    395 * @draft ICU 2.4
    396 */
    397 void IslamicCalendar::handleComputeFields(int32_t julianDay, UErrorCode &status) {
    398     int32_t year, month, dayOfMonth, dayOfYear;
    399     UDate startDate;
    400     int32_t days = julianDay - 1948440;
    401 
    402     if (civil == CIVIL) {
    403         // Use the civil calendar approximation, which is just arithmetic
    404         year  = (int)ClockMath::floorDivide( (double)(30 * days + 10646) , 10631.0 );
    405         month = (int32_t)uprv_ceil((days - 29 - yearStart(year)) / 29.5 );
    406         month = month<11?month:11;
    407         startDate = monthStart(year, month);
    408     } else {
    409         // Guess at the number of elapsed full months since the epoch
    410         int32_t months = (int32_t)uprv_floor((double)days / CalendarAstronomer::SYNODIC_MONTH);
    411 
    412         startDate = uprv_floor(months * CalendarAstronomer::SYNODIC_MONTH);
    413 
    414         double age = moonAge(internalGetTime(), status);
    415         if (U_FAILURE(status)) {
    416         	status = U_MEMORY_ALLOCATION_ERROR;
    417         	return;
    418         }
    419         if ( days - startDate >= 25 && age > 0) {
    420             // If we're near the end of the month, assume next month and search backwards
    421             months++;
    422         }
    423 
    424         // Find out the last time that the new moon was actually visible at this longitude
    425         // This returns midnight the night that the moon was visible at sunset.
    426         while ((startDate = trueMonthStart(months)) > days) {
    427             // If it was after the date in question, back up a month and try again
    428             months--;
    429         }
    430 
    431         year = months / 12 + 1;
    432         month = months % 12;
    433     }
    434 
    435     dayOfMonth = (days - monthStart(year, month)) + 1;
    436 
    437     // Now figure out the day of the year.
    438     dayOfYear = (days - monthStart(year, 0) + 1);
    439 
    440     internalSet(UCAL_ERA, 0);
    441     internalSet(UCAL_YEAR, year);
    442     internalSet(UCAL_EXTENDED_YEAR, year);
    443     internalSet(UCAL_MONTH, month);
    444     internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
    445     internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
    446 }
    447 
    448 UBool
    449 IslamicCalendar::inDaylightTime(UErrorCode& status) const
    450 {
    451     // copied from GregorianCalendar
    452     if (U_FAILURE(status) || (&(getTimeZone()) == NULL && !getTimeZone().useDaylightTime()))
    453         return FALSE;
    454 
    455     // Force an update of the state of the Calendar.
    456     ((IslamicCalendar*)this)->complete(status); // cast away const
    457 
    458     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
    459 }
    460 
    461 // default century
    462 const UDate     IslamicCalendar::fgSystemDefaultCentury        = DBL_MIN;
    463 const int32_t   IslamicCalendar::fgSystemDefaultCenturyYear    = -1;
    464 
    465 UDate           IslamicCalendar::fgSystemDefaultCenturyStart       = DBL_MIN;
    466 int32_t         IslamicCalendar::fgSystemDefaultCenturyStartYear   = -1;
    467 
    468 
    469 UBool IslamicCalendar::haveDefaultCentury() const
    470 {
    471     return TRUE;
    472 }
    473 
    474 UDate IslamicCalendar::defaultCenturyStart() const
    475 {
    476     return internalGetDefaultCenturyStart();
    477 }
    478 
    479 int32_t IslamicCalendar::defaultCenturyStartYear() const
    480 {
    481     return internalGetDefaultCenturyStartYear();
    482 }
    483 
    484 UDate
    485 IslamicCalendar::internalGetDefaultCenturyStart() const
    486 {
    487     // lazy-evaluate systemDefaultCenturyStart
    488     UBool needsUpdate;
    489     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
    490 
    491     if (needsUpdate) {
    492         initializeSystemDefaultCentury();
    493     }
    494 
    495     // use defaultCenturyStart unless it's the flag value;
    496     // then use systemDefaultCenturyStart
    497 
    498     return fgSystemDefaultCenturyStart;
    499 }
    500 
    501 int32_t
    502 IslamicCalendar::internalGetDefaultCenturyStartYear() const
    503 {
    504     // lazy-evaluate systemDefaultCenturyStartYear
    505     UBool needsUpdate;
    506     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
    507 
    508     if (needsUpdate) {
    509         initializeSystemDefaultCentury();
    510     }
    511 
    512     // use defaultCenturyStart unless it's the flag value;
    513     // then use systemDefaultCenturyStartYear
    514 
    515     return    fgSystemDefaultCenturyStartYear;
    516 }
    517 
    518 void
    519 IslamicCalendar::initializeSystemDefaultCentury()
    520 {
    521     // initialize systemDefaultCentury and systemDefaultCenturyYear based
    522     // on the current time.  They'll be set to 80 years before
    523     // the current time.
    524     UErrorCode status = U_ZERO_ERROR;
    525     IslamicCalendar calendar(Locale("@calendar=islamic-civil"),status);
    526     if (U_SUCCESS(status))
    527     {
    528         calendar.setTime(Calendar::getNow(), status);
    529         calendar.add(UCAL_YEAR, -80, status);
    530         UDate    newStart =  calendar.getTime(status);
    531         int32_t  newYear  =  calendar.get(UCAL_YEAR, status);
    532         umtx_lock(NULL);
    533         if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury)
    534         {
    535             fgSystemDefaultCenturyStartYear = newYear;
    536             fgSystemDefaultCenturyStart = newStart;
    537         }
    538         umtx_unlock(NULL);
    539     }
    540     // We have no recourse upon failure unless we want to propagate the failure
    541     // out.
    542 }
    543 
    544 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IslamicCalendar)
    545 
    546 U_NAMESPACE_END
    547 
    548 #endif
    549 
    550