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      1 /*
      2  * Copyright (C) 2003-2009, International Business Machines Corporation
      3  * and others. All Rights Reserved.
      4  ******************************************************************************
      5  *
      6  * File INDIANCAL.CPP
      7  *****************************************************************************
      8  */
      9 
     10 #include "indiancal.h"
     11 #include <stdlib.h>
     12 #if !UCONFIG_NO_FORMATTING
     13 
     14 #include "mutex.h"
     15 #include <float.h>
     16 #include "gregoimp.h" // Math
     17 #include "astro.h" // CalendarAstronomer
     18 #include "uhash.h"
     19 #include "ucln_in.h"
     20 
     21 // Debugging
     22 #ifdef U_DEBUG_INDIANCAL
     23 #include <stdio.h>
     24 #include <stdarg.h>
     25 
     26 #endif
     27 
     28 U_NAMESPACE_BEGIN
     29 
     30 // Implementation of the IndianCalendar class
     31 
     32 //-------------------------------------------------------------------------
     33 // Constructors...
     34 //-------------------------------------------------------------------------
     35 
     36 
     37 Calendar* IndianCalendar::clone() const {
     38   return new IndianCalendar(*this);
     39 }
     40 
     41 IndianCalendar::IndianCalendar(const Locale& aLocale, UErrorCode& success)
     42   :   Calendar(TimeZone::createDefault(), aLocale, success)
     43 {
     44   setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
     45 }
     46 
     47 IndianCalendar::IndianCalendar(const IndianCalendar& other) : Calendar(other) {
     48 }
     49 
     50 IndianCalendar::~IndianCalendar()
     51 {
     52 }
     53 const char *IndianCalendar::getType() const {
     54    return "indian";
     55 }
     56 
     57 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
     58     // Minimum  Greatest     Least   Maximum
     59     //           Minimum   Maximum
     60     {        0,        0,        0,        0}, // ERA
     61     { -5000000, -5000000,  5000000,  5000000}, // YEAR
     62     {        0,        0,       11,       11}, // MONTH
     63     {        1,        1,       52,       53}, // WEEK_OF_YEAR
     64     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
     65     {        1,        1,       30,       31}, // DAY_OF_MONTH
     66     {        1,        1,      365,      366}, // DAY_OF_YEAR
     67     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
     68     {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
     69     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
     70     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
     71     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
     72     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
     73     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
     74     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
     75     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
     76     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
     77     { -5000000, -5000000,  5000000,  5000000}, // YEAR_WOY
     78     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
     79     { -5000000, -5000000,  5000000,  5000000}, // EXTENDED_YEAR
     80     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
     81     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
     82     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
     83 };
     84 
     85 static const double JULIAN_EPOCH = 1721425.5;
     86 static const int32_t INDIAN_ERA_START  = 78;
     87 static const int32_t INDIAN_YEAR_START = 80;
     88 
     89 int32_t IndianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
     90   return LIMITS[field][limitType];
     91 }
     92 
     93 /*
     94  * Determine whether the given gregorian year is a Leap year
     95  */
     96 static UBool isGregorianLeap(int32_t year)
     97 {
     98     return ((year % 4) == 0) && (!(((year % 100) == 0) && ((year % 400) != 0)));
     99 }
    100 
    101 //----------------------------------------------------------------------
    102 // Calendar framework
    103 //----------------------------------------------------------------------
    104 
    105 /*
    106  * Return the length (in days) of the given month.
    107  *
    108  * @param eyear  The year in Saka Era
    109  * @param month  The month(0-based) in Indian calendar
    110  */
    111 int32_t IndianCalendar::handleGetMonthLength(int32_t eyear, int32_t month) const {
    112    if (month < 0 || month > 11) {
    113       eyear += ClockMath::floorDivide(month, 12, month);
    114    }
    115 
    116    if (isGregorianLeap(eyear + INDIAN_ERA_START) && month == 0) {
    117        return 31;
    118    }
    119 
    120    if (month >= 1 && month <= 5) {
    121        return 31;
    122    }
    123 
    124    return 30;
    125 }
    126 
    127 /*
    128  * Return the number of days in the given Indian year
    129  *
    130  * @param eyear The year in Saka Era.
    131  */
    132 int32_t IndianCalendar::handleGetYearLength(int32_t eyear) const {
    133     return isGregorianLeap(eyear + INDIAN_ERA_START) ? 366 : 365;
    134 }
    135 /*
    136  * Returns the Julian Day corresponding to gregorian date
    137  *
    138  * @param year The Gregorian year
    139  * @param month The month in Gregorian Year
    140  * @param date The date in Gregorian day in month
    141  */
    142 static double gregorianToJD(int32_t year, int32_t month, int32_t date) {
    143    double julianDay = (JULIAN_EPOCH - 1) +
    144       (365 * (year - 1)) +
    145       uprv_floor((year - 1) / 4) +
    146       (-uprv_floor((year - 1) / 100)) +
    147       uprv_floor((year - 1) / 400) +
    148       uprv_floor((((367 * month) - 362) / 12) +
    149             ((month <= 2) ? 0 :
    150              (isGregorianLeap(year) ? -1 : -2)
    151             ) +
    152             date);
    153 
    154    return julianDay;
    155 }
    156 
    157 /*
    158  * Returns the Gregorian Date corresponding to a given Julian Day
    159  * @param jd The Julian Day
    160  */
    161 static int32_t* jdToGregorian(double jd, int32_t gregorianDate[3]) {
    162    double wjd, depoch, quadricent, dqc, cent, dcent, quad, dquad, yindex, yearday, leapadj;
    163    int32_t year, month, day;
    164    wjd = uprv_floor(jd - 0.5) + 0.5;
    165    depoch = wjd - JULIAN_EPOCH;
    166    quadricent = uprv_floor(depoch / 146097);
    167    dqc = (int32_t)uprv_floor(depoch) % 146097;
    168    cent = uprv_floor(dqc / 36524);
    169    dcent = (int32_t)uprv_floor(dqc) % 36524;
    170    quad = uprv_floor(dcent / 1461);
    171    dquad = (int32_t)uprv_floor(dcent) % 1461;
    172    yindex = uprv_floor(dquad / 365);
    173    year = (int32_t)((quadricent * 400) + (cent * 100) + (quad * 4) + yindex);
    174    if (!((cent == 4) || (yindex == 4))) {
    175       year++;
    176    }
    177    yearday = wjd - gregorianToJD(year, 1, 1);
    178    leapadj = ((wjd < gregorianToJD(year, 3, 1)) ? 0
    179          :
    180          (isGregorianLeap(year) ? 1 : 2)
    181          );
    182    month = (int32_t)uprv_floor((((yearday + leapadj) * 12) + 373) / 367);
    183    day = (int32_t)(wjd - gregorianToJD(year, month, 1)) + 1;
    184 
    185    gregorianDate[0] = year;
    186    gregorianDate[1] = month;
    187    gregorianDate[2] = day;
    188 
    189    return gregorianDate;
    190 }
    191 
    192 
    193 //-------------------------------------------------------------------------
    194 // Functions for converting from field values to milliseconds....
    195 //-------------------------------------------------------------------------
    196 static double IndianToJD(int32_t year, int32_t month, int32_t date) {
    197    int32_t leapMonth, gyear, m;
    198    double start, jd;
    199 
    200    gyear = year + INDIAN_ERA_START;
    201 
    202 
    203    if(isGregorianLeap(gyear)) {
    204       leapMonth = 31;
    205       start = gregorianToJD(gyear, 3, 21);
    206    }
    207    else {
    208       leapMonth = 30;
    209       start = gregorianToJD(gyear, 3, 22);
    210    }
    211 
    212    if (month == 1) {
    213       jd = start + (date - 1);
    214    } else {
    215       jd = start + leapMonth;
    216       m = month - 2;
    217 
    218       //m = Math.min(m, 5);
    219       if (m > 5) {
    220           m = 5;
    221       }
    222 
    223       jd += m * 31;
    224 
    225       if (month >= 8) {
    226          m = month - 7;
    227          jd += m * 30;
    228       }
    229       jd += date - 1;
    230    }
    231 
    232    return jd;
    233 }
    234 
    235 /*
    236  * Return JD of start of given month/year of Indian Calendar
    237  * @param eyear The year in Indian Calendar measured from Saka Era (78 AD).
    238  * @param month The month in Indian calendar
    239  */
    240 int32_t IndianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */ ) const {
    241 
    242    //month is 0 based; converting it to 1-based
    243    int32_t imonth;
    244 
    245     // If the month is out of range, adjust it into range, and adjust the extended eyar accordingly
    246    if (month < 0 || month > 11) {
    247       eyear += (int32_t)ClockMath::floorDivide(month, 12, month);
    248    }
    249 
    250    if(month == 12){
    251        imonth = 1;
    252    } else {
    253        imonth = month + 1;
    254    }
    255 
    256    double jd = IndianToJD(eyear ,imonth, 1);
    257 
    258    return (int32_t)jd;
    259 }
    260 
    261 //-------------------------------------------------------------------------
    262 // Functions for converting from milliseconds to field values
    263 //-------------------------------------------------------------------------
    264 
    265 int32_t IndianCalendar::handleGetExtendedYear() {
    266     int32_t year;
    267 
    268     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
    269         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
    270     } else {
    271         year = internalGet(UCAL_YEAR, 1); // Default to year 1
    272     }
    273 
    274     return year;
    275 }
    276 
    277 /*
    278  * Override Calendar to compute several fields specific to the Indian
    279  * calendar system.  These are:
    280  *
    281  * <ul><li>ERA
    282  * <li>YEAR
    283  * <li>MONTH
    284  * <li>DAY_OF_MONTH
    285  * <li>EXTENDED_YEAR</ul>
    286  *
    287  * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
    288  * method is called. The getGregorianXxx() methods return Gregorian
    289  * calendar equivalents for the given Julian day.
    290  */
    291 void IndianCalendar::handleComputeFields(int32_t julianDay, UErrorCode&  /* status */) {
    292     double jdAtStartOfGregYear;
    293     int32_t leapMonth, IndianYear, yday, IndianMonth, IndianDayOfMonth, mday;
    294     int32_t gregorianYear;      // Stores gregorian date corresponding to Julian day;
    295     int32_t gd[3];
    296 
    297     gregorianYear = jdToGregorian(julianDay, gd)[0];          // Gregorian date for Julian day
    298     IndianYear = gregorianYear - INDIAN_ERA_START;            // Year in Saka era
    299     jdAtStartOfGregYear = gregorianToJD(gregorianYear, 1, 1); // JD at start of Gregorian year
    300     yday = (int32_t)(julianDay - jdAtStartOfGregYear);        // Day number in Gregorian year (starting from 0)
    301 
    302     if (yday < INDIAN_YEAR_START) {
    303         // Day is at the end of the preceding Saka year
    304         IndianYear -= 1;
    305         leapMonth = isGregorianLeap(gregorianYear - 1) ? 31 : 30; // Days in leapMonth this year, previous Gregorian year
    306         yday += leapMonth + (31 * 5) + (30 * 3) + 10;
    307     } else {
    308         leapMonth = isGregorianLeap(gregorianYear) ? 31 : 30; // Days in leapMonth this year
    309         yday -= INDIAN_YEAR_START;
    310     }
    311 
    312     if (yday < leapMonth) {
    313         IndianMonth = 0;
    314         IndianDayOfMonth = yday + 1;
    315     } else {
    316         mday = yday - leapMonth;
    317         if (mday < (31 * 5)) {
    318             IndianMonth = (int32_t)uprv_floor(mday / 31) + 1;
    319             IndianDayOfMonth = (mday % 31) + 1;
    320         } else {
    321             mday -= 31 * 5;
    322             IndianMonth = (int32_t)uprv_floor(mday / 30) + 6;
    323             IndianDayOfMonth = (mday % 30) + 1;
    324         }
    325    }
    326 
    327    internalSet(UCAL_ERA, 0);
    328    internalSet(UCAL_EXTENDED_YEAR, IndianYear);
    329    internalSet(UCAL_YEAR, IndianYear);
    330    internalSet(UCAL_MONTH, IndianMonth);
    331    internalSet(UCAL_DAY_OF_MONTH, IndianDayOfMonth);
    332    internalSet(UCAL_DAY_OF_YEAR, yday + 1); // yday is 0-based
    333 }
    334 
    335 UBool
    336 IndianCalendar::inDaylightTime(UErrorCode& status) const
    337 {
    338     // copied from GregorianCalendar
    339     if (U_FAILURE(status) || !getTimeZone().useDaylightTime()) {
    340         return FALSE;
    341     }
    342 
    343     // Force an update of the state of the Calendar.
    344     ((IndianCalendar*)this)->complete(status); // cast away const
    345 
    346     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
    347 }
    348 
    349 // default century
    350 const UDate     IndianCalendar::fgSystemDefaultCentury          = DBL_MIN;
    351 const int32_t   IndianCalendar::fgSystemDefaultCenturyYear      = -1;
    352 
    353 UDate           IndianCalendar::fgSystemDefaultCenturyStart     = DBL_MIN;
    354 int32_t         IndianCalendar::fgSystemDefaultCenturyStartYear = -1;
    355 
    356 
    357 UBool IndianCalendar::haveDefaultCentury() const
    358 {
    359     return TRUE;
    360 }
    361 
    362 UDate IndianCalendar::defaultCenturyStart() const
    363 {
    364     return internalGetDefaultCenturyStart();
    365 }
    366 
    367 int32_t IndianCalendar::defaultCenturyStartYear() const
    368 {
    369     return internalGetDefaultCenturyStartYear();
    370 }
    371 
    372 UDate
    373 IndianCalendar::internalGetDefaultCenturyStart() const
    374 {
    375     // lazy-evaluate systemDefaultCenturyStart
    376     UBool needsUpdate;
    377     {
    378         Mutex m;
    379         needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
    380     }
    381 
    382     if (needsUpdate) {
    383         initializeSystemDefaultCentury();
    384     }
    385 
    386     // use defaultCenturyStart unless it's the flag value;
    387     // then use systemDefaultCenturyStart
    388 
    389     return fgSystemDefaultCenturyStart;
    390 }
    391 
    392 int32_t
    393 IndianCalendar::internalGetDefaultCenturyStartYear() const
    394 {
    395     // lazy-evaluate systemDefaultCenturyStartYear
    396     UBool needsUpdate;
    397     {
    398         Mutex m;
    399 
    400         needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
    401     }
    402 
    403     if (needsUpdate) {
    404         initializeSystemDefaultCentury();
    405     }
    406 
    407     // use defaultCenturyStart unless it's the flag value;
    408     // then use systemDefaultCenturyStartYear
    409 
    410     return    fgSystemDefaultCenturyStartYear;
    411 }
    412 
    413 void
    414 IndianCalendar::initializeSystemDefaultCentury()
    415 {
    416     // initialize systemDefaultCentury and systemDefaultCenturyYear based
    417     // on the current time.  They'll be set to 80 years before
    418     // the current time.
    419     // No point in locking as it should be idempotent.
    420     if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury) {
    421         UErrorCode status = U_ZERO_ERROR;
    422 
    423         IndianCalendar calendar(Locale("@calendar=Indian"),status);
    424         if (U_SUCCESS(status)) {
    425             calendar.setTime(Calendar::getNow(), status);
    426             calendar.add(UCAL_YEAR, -80, status);
    427 
    428             UDate    newStart = calendar.getTime(status);
    429             int32_t  newYear  = calendar.get(UCAL_YEAR, status);
    430 
    431             {
    432                 Mutex m;
    433 
    434                 fgSystemDefaultCenturyStart = newStart;
    435                 fgSystemDefaultCenturyStartYear = newYear;
    436             }
    437         }
    438 
    439         // We have no recourse upon failure unless we want to propagate the failure
    440         // out.
    441     }
    442 }
    443 
    444 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IndianCalendar)
    445 
    446 U_NAMESPACE_END
    447 
    448 #endif
    449 
    450