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      1 /*
      2 ******************************************************************************
      3 * Copyright (C) 2003-2012, 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 UMutex astroLock = U_MUTEX_INITIALIZER;  // pod bay door lock
     55 static icu::CalendarCache *gMonthCache = NULL;
     56 static icu::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     return TRUE;
     69 }
     70 U_CDECL_END
     71 
     72 U_NAMESPACE_BEGIN
     73 
     74 // Implementation of the IslamicCalendar class
     75 
     76 //-------------------------------------------------------------------------
     77 // Constructors...
     78 //-------------------------------------------------------------------------
     79 
     80 const char *IslamicCalendar::getType() const {
     81     if(civil==CIVIL) {
     82         return "islamic-civil";
     83     } else {
     84         return "islamic";
     85     }
     86 }
     87 
     88 Calendar* IslamicCalendar::clone() const {
     89     return new IslamicCalendar(*this);
     90 }
     91 
     92 IslamicCalendar::IslamicCalendar(const Locale& aLocale, UErrorCode& success, ECivil beCivil)
     93 :   Calendar(TimeZone::createDefault(), aLocale, success),
     94 civil(beCivil)
     95 {
     96     setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
     97 }
     98 
     99 IslamicCalendar::IslamicCalendar(const IslamicCalendar& other) : Calendar(other), civil(other.civil) {
    100 }
    101 
    102 IslamicCalendar::~IslamicCalendar()
    103 {
    104 }
    105 
    106 /**
    107 * Determines whether this object uses the fixed-cycle Islamic civil calendar
    108 * or an approximation of the religious, astronomical calendar.
    109 *
    110 * @param beCivil   <code>true</code> to use the civil calendar,
    111 *                  <code>false</code> to use the astronomical calendar.
    112 * @draft ICU 2.4
    113 */
    114 void IslamicCalendar::setCivil(ECivil beCivil, UErrorCode &status)
    115 {
    116     if (civil != beCivil) {
    117         // The fields of the calendar will become invalid, because the calendar
    118         // rules are different
    119         UDate m = getTimeInMillis(status);
    120         civil = beCivil;
    121         clear();
    122         setTimeInMillis(m, status);
    123     }
    124 }
    125 
    126 /**
    127 * Returns <code>true</code> if this object is using the fixed-cycle civil
    128 * calendar, or <code>false</code> if using the religious, astronomical
    129 * calendar.
    130 * @draft ICU 2.4
    131 */
    132 UBool IslamicCalendar::isCivil() {
    133     return (civil == CIVIL);
    134 }
    135 
    136 //-------------------------------------------------------------------------
    137 // Minimum / Maximum access functions
    138 //-------------------------------------------------------------------------
    139 
    140 // Note: Current IslamicCalendar implementation does not work
    141 // well with negative years.
    142 
    143 // TODO: In some cases the current ICU Islamic calendar implementation shows
    144 // a month as having 31 days. Since date parsing now uses range checks based
    145 // on the table below, we need to change the range for last day of month to
    146 // include 31 as a workaround until the implementation is fixed.
    147 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
    148     // Minimum  Greatest    Least  Maximum
    149     //           Minimum  Maximum
    150     {        0,        0,        0,        0}, // ERA
    151     {        1,        1,  5000000,  5000000}, // YEAR
    152     {        0,        0,       11,       11}, // MONTH
    153     {        1,        1,       50,       51}, // WEEK_OF_YEAR
    154     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
    155     {        1,        1,       29,       31}, // DAY_OF_MONTH - 31 to workaround for cal implementation bug, should be 30
    156     {        1,        1,      354,      355}, // DAY_OF_YEAR
    157     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
    158     {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
    159     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
    160     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
    161     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
    162     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
    163     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
    164     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
    165     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
    166     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
    167     {        1,        1,  5000000,  5000000}, // YEAR_WOY
    168     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
    169     {        1,        1,  5000000,  5000000}, // EXTENDED_YEAR
    170     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
    171     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
    172     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
    173 };
    174 
    175 /**
    176 * @draft ICU 2.4
    177 */
    178 int32_t IslamicCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
    179     return LIMITS[field][limitType];
    180 }
    181 
    182 //-------------------------------------------------------------------------
    183 // Assorted calculation utilities
    184 //
    185 
    186 /**
    187 * Determine whether a year is a leap year in the Islamic civil calendar
    188 */
    189 UBool IslamicCalendar::civilLeapYear(int32_t year)
    190 {
    191     return (14 + 11 * year) % 30 < 11;
    192 }
    193 
    194 /**
    195 * Return the day # on which the given year starts.  Days are counted
    196 * from the Hijri epoch, origin 0.
    197 */
    198 int32_t IslamicCalendar::yearStart(int32_t year) {
    199     if (civil == CIVIL) {
    200         return (year-1)*354 + ClockMath::floorDivide((3+11*year),30);
    201     } else {
    202         return trueMonthStart(12*(year-1));
    203     }
    204 }
    205 
    206 /**
    207 * Return the day # on which the given month starts.  Days are counted
    208 * from the Hijri epoch, origin 0.
    209 *
    210 * @param year  The hijri year
    211 * @param year  The hijri month, 0-based
    212 */
    213 int32_t IslamicCalendar::monthStart(int32_t year, int32_t month) const {
    214     if (civil == CIVIL) {
    215         return (int32_t)uprv_ceil(29.5*month)
    216             + (year-1)*354 + (int32_t)ClockMath::floorDivide((3+11*year),30);
    217     } else {
    218         return trueMonthStart(12*(year-1) + month);
    219     }
    220 }
    221 
    222 /**
    223 * Find the day number on which a particular month of the true/lunar
    224 * Islamic calendar starts.
    225 *
    226 * @param month The month in question, origin 0 from the Hijri epoch
    227 *
    228 * @return The day number on which the given month starts.
    229 */
    230 int32_t IslamicCalendar::trueMonthStart(int32_t month) const
    231 {
    232     UErrorCode status = U_ZERO_ERROR;
    233     int32_t start = CalendarCache::get(&gMonthCache, month, status);
    234 
    235     if (start==0) {
    236         // Make a guess at when the month started, using the average length
    237         UDate origin = HIJRA_MILLIS
    238             + uprv_floor(month * CalendarAstronomer::SYNODIC_MONTH) * kOneDay;
    239 
    240         // moonAge will fail due to memory allocation error
    241         double age = moonAge(origin, status);
    242         if (U_FAILURE(status)) {
    243             goto trueMonthStartEnd;
    244         }
    245 
    246         if (age >= 0) {
    247             // The month has already started
    248             do {
    249                 origin -= kOneDay;
    250                 age = moonAge(origin, status);
    251                 if (U_FAILURE(status)) {
    252                     goto trueMonthStartEnd;
    253                 }
    254             } while (age >= 0);
    255         }
    256         else {
    257             // Preceding month has not ended yet.
    258             do {
    259                 origin += kOneDay;
    260                 age = moonAge(origin, status);
    261                 if (U_FAILURE(status)) {
    262                     goto trueMonthStartEnd;
    263                 }
    264             } while (age < 0);
    265         }
    266         start = (int32_t)ClockMath::floorDivide((origin - HIJRA_MILLIS), (double)kOneDay) + 1;
    267         CalendarCache::put(&gMonthCache, month, start, status);
    268     }
    269 trueMonthStartEnd :
    270     if(U_FAILURE(status)) {
    271         start = 0;
    272     }
    273     return start;
    274 }
    275 
    276 /**
    277 * Return the "age" of the moon at the given time; this is the difference
    278 * in ecliptic latitude between the moon and the sun.  This method simply
    279 * calls CalendarAstronomer.moonAge, converts to degrees,
    280 * and adjusts the result to be in the range [-180, 180].
    281 *
    282 * @param time  The time at which the moon's age is desired,
    283 *              in millis since 1/1/1970.
    284 */
    285 double IslamicCalendar::moonAge(UDate time, UErrorCode &status)
    286 {
    287     double age = 0;
    288 
    289     umtx_lock(&astroLock);
    290     if(gIslamicCalendarAstro == NULL) {
    291         gIslamicCalendarAstro = new CalendarAstronomer();
    292         if (gIslamicCalendarAstro == NULL) {
    293             status = U_MEMORY_ALLOCATION_ERROR;
    294             return age;
    295         }
    296         ucln_i18n_registerCleanup(UCLN_I18N_ISLAMIC_CALENDAR, calendar_islamic_cleanup);
    297     }
    298     gIslamicCalendarAstro->setTime(time);
    299     age = gIslamicCalendarAstro->getMoonAge();
    300     umtx_unlock(&astroLock);
    301 
    302     // Convert to degrees and normalize...
    303     age = age * 180 / CalendarAstronomer::PI;
    304     if (age > 180) {
    305         age = age - 360;
    306     }
    307 
    308     return age;
    309 }
    310 
    311 //----------------------------------------------------------------------
    312 // Calendar framework
    313 //----------------------------------------------------------------------
    314 
    315 /**
    316 * Return the length (in days) of the given month.
    317 *
    318 * @param year  The hijri year
    319 * @param year  The hijri month, 0-based
    320 * @draft ICU 2.4
    321 */
    322 int32_t IslamicCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
    323 
    324     int32_t length = 0;
    325 
    326     if (civil == CIVIL) {
    327         length = 29 + (month+1) % 2;
    328         if (month == DHU_AL_HIJJAH && civilLeapYear(extendedYear)) {
    329             length++;
    330         }
    331     } else {
    332         month = 12*(extendedYear-1) + month;
    333         length =  trueMonthStart(month+1) - trueMonthStart(month) ;
    334     }
    335     return length;
    336 }
    337 
    338 /**
    339 * Return the number of days in the given Islamic year
    340 * @draft ICU 2.4
    341 */
    342 int32_t IslamicCalendar::handleGetYearLength(int32_t extendedYear) const {
    343     if (civil == CIVIL) {
    344         return 354 + (civilLeapYear(extendedYear) ? 1 : 0);
    345     } else {
    346         int32_t month = 12*(extendedYear-1);
    347         return (trueMonthStart(month + 12) - trueMonthStart(month));
    348     }
    349 }
    350 
    351 //-------------------------------------------------------------------------
    352 // Functions for converting from field values to milliseconds....
    353 //-------------------------------------------------------------------------
    354 
    355 // Return JD of start of given month/year
    356 /**
    357 * @draft ICU 2.4
    358 */
    359 int32_t IslamicCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */) const {
    360     return monthStart(eyear, month) + 1948439;
    361 }
    362 
    363 //-------------------------------------------------------------------------
    364 // Functions for converting from milliseconds to field values
    365 //-------------------------------------------------------------------------
    366 
    367 /**
    368 * @draft ICU 2.4
    369 */
    370 int32_t IslamicCalendar::handleGetExtendedYear() {
    371     int32_t year;
    372     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
    373         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
    374     } else {
    375         year = internalGet(UCAL_YEAR, 1); // Default to year 1
    376     }
    377     return year;
    378 }
    379 
    380 /**
    381 * Override Calendar to compute several fields specific to the Islamic
    382 * calendar system.  These are:
    383 *
    384 * <ul><li>ERA
    385 * <li>YEAR
    386 * <li>MONTH
    387 * <li>DAY_OF_MONTH
    388 * <li>DAY_OF_YEAR
    389 * <li>EXTENDED_YEAR</ul>
    390 *
    391 * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
    392 * method is called. The getGregorianXxx() methods return Gregorian
    393 * calendar equivalents for the given Julian day.
    394 * @draft ICU 2.4
    395 */
    396 void IslamicCalendar::handleComputeFields(int32_t julianDay, UErrorCode &status) {
    397     int32_t year, month, dayOfMonth, dayOfYear;
    398     UDate startDate;
    399     int32_t days = julianDay - 1948440;
    400 
    401     if (civil == CIVIL) {
    402         // Use the civil calendar approximation, which is just arithmetic
    403         year  = (int)ClockMath::floorDivide( (double)(30 * days + 10646) , 10631.0 );
    404         month = (int32_t)uprv_ceil((days - 29 - yearStart(year)) / 29.5 );
    405         month = month<11?month:11;
    406         startDate = monthStart(year, month);
    407     } else {
    408         // Guess at the number of elapsed full months since the epoch
    409         int32_t months = (int32_t)uprv_floor((double)days / CalendarAstronomer::SYNODIC_MONTH);
    410 
    411         startDate = uprv_floor(months * CalendarAstronomer::SYNODIC_MONTH);
    412 
    413         double age = moonAge(internalGetTime(), status);
    414         if (U_FAILURE(status)) {
    415         	status = U_MEMORY_ALLOCATION_ERROR;
    416         	return;
    417         }
    418         if ( days - startDate >= 25 && age > 0) {
    419             // If we're near the end of the month, assume next month and search backwards
    420             months++;
    421         }
    422 
    423         // Find out the last time that the new moon was actually visible at this longitude
    424         // This returns midnight the night that the moon was visible at sunset.
    425         while ((startDate = trueMonthStart(months)) > days) {
    426             // If it was after the date in question, back up a month and try again
    427             months--;
    428         }
    429 
    430         year = months / 12 + 1;
    431         month = months % 12;
    432     }
    433 
    434     dayOfMonth = (days - monthStart(year, month)) + 1;
    435 
    436     // Now figure out the day of the year.
    437     dayOfYear = (days - monthStart(year, 0) + 1);
    438 
    439     internalSet(UCAL_ERA, 0);
    440     internalSet(UCAL_YEAR, year);
    441     internalSet(UCAL_EXTENDED_YEAR, year);
    442     internalSet(UCAL_MONTH, month);
    443     internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
    444     internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
    445 }
    446 
    447 UBool
    448 IslamicCalendar::inDaylightTime(UErrorCode& status) const
    449 {
    450     // copied from GregorianCalendar
    451     if (U_FAILURE(status) || (&(getTimeZone()) == NULL && !getTimeZone().useDaylightTime()))
    452         return FALSE;
    453 
    454     // Force an update of the state of the Calendar.
    455     ((IslamicCalendar*)this)->complete(status); // cast away const
    456 
    457     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
    458 }
    459 
    460 // default century
    461 const UDate     IslamicCalendar::fgSystemDefaultCentury        = DBL_MIN;
    462 const int32_t   IslamicCalendar::fgSystemDefaultCenturyYear    = -1;
    463 
    464 UDate           IslamicCalendar::fgSystemDefaultCenturyStart       = DBL_MIN;
    465 int32_t         IslamicCalendar::fgSystemDefaultCenturyStartYear   = -1;
    466 
    467 
    468 UBool IslamicCalendar::haveDefaultCentury() const
    469 {
    470     return TRUE;
    471 }
    472 
    473 UDate IslamicCalendar::defaultCenturyStart() const
    474 {
    475     return internalGetDefaultCenturyStart();
    476 }
    477 
    478 int32_t IslamicCalendar::defaultCenturyStartYear() const
    479 {
    480     return internalGetDefaultCenturyStartYear();
    481 }
    482 
    483 UDate
    484 IslamicCalendar::internalGetDefaultCenturyStart() const
    485 {
    486     // lazy-evaluate systemDefaultCenturyStart
    487     UBool needsUpdate;
    488     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
    489 
    490     if (needsUpdate) {
    491         initializeSystemDefaultCentury();
    492     }
    493 
    494     // use defaultCenturyStart unless it's the flag value;
    495     // then use systemDefaultCenturyStart
    496 
    497     return fgSystemDefaultCenturyStart;
    498 }
    499 
    500 int32_t
    501 IslamicCalendar::internalGetDefaultCenturyStartYear() const
    502 {
    503     // lazy-evaluate systemDefaultCenturyStartYear
    504     UBool needsUpdate;
    505     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
    506 
    507     if (needsUpdate) {
    508         initializeSystemDefaultCentury();
    509     }
    510 
    511     // use defaultCenturyStart unless it's the flag value;
    512     // then use systemDefaultCenturyStartYear
    513 
    514     return    fgSystemDefaultCenturyStartYear;
    515 }
    516 
    517 void
    518 IslamicCalendar::initializeSystemDefaultCentury()
    519 {
    520     // initialize systemDefaultCentury and systemDefaultCenturyYear based
    521     // on the current time.  They'll be set to 80 years before
    522     // the current time.
    523     UErrorCode status = U_ZERO_ERROR;
    524     IslamicCalendar calendar(Locale("@calendar=islamic-civil"),status);
    525     if (U_SUCCESS(status))
    526     {
    527         calendar.setTime(Calendar::getNow(), status);
    528         calendar.add(UCAL_YEAR, -80, status);
    529         UDate    newStart =  calendar.getTime(status);
    530         int32_t  newYear  =  calendar.get(UCAL_YEAR, status);
    531         umtx_lock(NULL);
    532         if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury)
    533         {
    534             fgSystemDefaultCenturyStartYear = newYear;
    535             fgSystemDefaultCenturyStart = newStart;
    536         }
    537         umtx_unlock(NULL);
    538     }
    539     // We have no recourse upon failure unless we want to propagate the failure
    540     // out.
    541 }
    542 
    543 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IslamicCalendar)
    544 
    545 U_NAMESPACE_END
    546 
    547 #endif
    548 
    549