icuSources/i18n/indiancal.cpp

   1 /*
   2  * Copyright (C) 2003-2008, 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 += Math::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)Math::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