icuSources/i18n/indiancal.cpp

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4  * Copyright (C) 2003-2014, International Business Machines Corporation
   5  * and others. All Rights Reserved.
   6  ******************************************************************************
   7  *
   8  * File INDIANCAL.CPP
   9  *****************************************************************************
  10  */
  11
  12 #include "indiancal.h"
  13 #include <stdlib.h>
  14 #if !UCONFIG_NO_FORMATTING
  15
  16 #include "mutex.h"
  17 #include <float.h>
  18 #include "gregoimp.h" // Math
  19 #include "astro.h" // CalendarAstronomer
  20 #include "uhash.h"
  21
  22 // Debugging
  23 #ifdef U_DEBUG_INDIANCAL
  24 #include <stdio.h>
  25 #include <stdarg.h>
  26
  27 #endif
  28
  29 U_NAMESPACE_BEGIN
  30
  31 // Implementation of the IndianCalendar class
  32
  33 //-------------------------------------------------------------------------
  34 // Constructors...
  35 //-------------------------------------------------------------------------
  36
  37
  38 Calendar* IndianCalendar::clone() const {
  39   return new IndianCalendar(*this);
  40 }
  41
  42 IndianCalendar::IndianCalendar(const Locale& aLocale, UErrorCode& success)
  43   :   Calendar(TimeZone::createDefault(), aLocale, success)
  44 {
  45   setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
  46 }
  47
  48 IndianCalendar::IndianCalendar(const IndianCalendar& other) : Calendar(other) {
  49 }
  50
  51 IndianCalendar::~IndianCalendar()
  52 {
  53 }
  54 const char *IndianCalendar::getType() const {
  55    return "indian";
  56 }
  57
  58 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
  59     // Minimum  Greatest     Least   Maximum
  60     //           Minimum   Maximum
  61     {        0,        0,        0,        0}, // ERA
  62     { -5000000, -5000000,  5000000,  5000000}, // YEAR
  63     {        0,        0,       11,       11}, // MONTH
  64     {        1,        1,       52,       53}, // WEEK_OF_YEAR
  65     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
  66     {        1,        1,       30,       31}, // DAY_OF_MONTH
  67     {        1,        1,      365,      366}, // DAY_OF_YEAR
  68     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
  69     {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
  70     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
  71     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
  72     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
  73     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
  74     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
  75     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
  76     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
  77     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
  78     { -5000000, -5000000,  5000000,  5000000}, // YEAR_WOY
  79     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
  80     { -5000000, -5000000,  5000000,  5000000}, // EXTENDED_YEAR
  81     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
  82     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
  83     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
  84 };
  85
  86 static const double JULIAN_EPOCH = 1721425.5;
  87 static const int32_t INDIAN_ERA_START  = 78;
  88 static const int32_t INDIAN_YEAR_START = 80;
  89
  90 int32_t IndianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
  91   return LIMITS[field][limitType];
  92 }
  93
  94 /*
  95  * Determine whether the given gregorian year is a Leap year
  96  */
  97 static UBool isGregorianLeap(int32_t year)
  98 {
  99     return ((year % 4) == 0) && (!(((year % 100) == 0) && ((year % 400) != 0)));
 100 }
 101
 102 //----------------------------------------------------------------------
 103 // Calendar framework
 104 //----------------------------------------------------------------------
 105
 106 /*
 107  * Return the length (in days) of the given month.
 108  *
 109  * @param eyear  The year in Saka Era
 110  * @param month  The month(0-based) in Indian calendar
 111  */
 112 int32_t IndianCalendar::handleGetMonthLength(int32_t eyear, int32_t month) const {
 113    if (month < 0 || month > 11) {
 114       eyear += ClockMath::floorDivide(month, 12, month);
 115    }
 116
 117    if (isGregorianLeap(eyear + INDIAN_ERA_START) && month == 0) {
 118        return 31;
 119    }
 120
 121    if (month >= 1 && month <= 5) {
 122        return 31;
 123    }
 124
 125    return 30;
 126 }
 127
 128 /*
 129  * Return the number of days in the given Indian year
 130  *
 131  * @param eyear The year in Saka Era.
 132  */
 133 int32_t IndianCalendar::handleGetYearLength(int32_t eyear) const {
 134     return isGregorianLeap(eyear + INDIAN_ERA_START) ? 366 : 365;
 135 }
 136 /*
 137  * Returns the Julian Day corresponding to gregorian date
 138  *
 139  * @param year The Gregorian year
 140  * @param month The month in Gregorian Year
 141  * @param date The date in Gregorian day in month
 142  */
 143 static double gregorianToJD(int32_t year, int32_t month, int32_t date) {
 144    double julianDay = (JULIAN_EPOCH - 1) +
 145       (365 * (year - 1)) +
 146       uprv_floor((year - 1) / 4) +
 147       (-uprv_floor((year - 1) / 100)) +
 148       uprv_floor((year - 1) / 400) +
 149       uprv_floor((((367 * month) - 362) / 12) +
 150             ((month <= 2) ? 0 :
 151              (isGregorianLeap(year) ? -1 : -2)
 152             ) +
 153             date);
 154
 155    return julianDay;
 156 }
 157
 158 /*
 159  * Returns the Gregorian Date corresponding to a given Julian Day
 160  * @param jd The Julian Day
 161  */
 162 static int32_t* jdToGregorian(double jd, int32_t gregorianDate[3]) {
 163    double wjd, depoch, quadricent, dqc, cent, dcent, quad, dquad, yindex, yearday, leapadj;
 164    int32_t year, month, day;
 165    wjd = uprv_floor(jd - 0.5) + 0.5;
 166    depoch = wjd - JULIAN_EPOCH;
 167    quadricent = uprv_floor(depoch / 146097);
 168    dqc = (int32_t)uprv_floor(depoch) % 146097;
 169    cent = uprv_floor(dqc / 36524);
 170    dcent = (int32_t)uprv_floor(dqc) % 36524;
 171    quad = uprv_floor(dcent / 1461);
 172    dquad = (int32_t)uprv_floor(dcent) % 1461;
 173    yindex = uprv_floor(dquad / 365);
 174    year = (int32_t)((quadricent * 400) + (cent * 100) + (quad * 4) + yindex);
 175    if (!((cent == 4) || (yindex == 4))) {
 176       year++;
 177    }
 178    yearday = wjd - gregorianToJD(year, 1, 1);
 179    leapadj = ((wjd < gregorianToJD(year, 3, 1)) ? 0
 180          :
 181          (isGregorianLeap(year) ? 1 : 2)
 182          );
 183    month = (int32_t)uprv_floor((((yearday + leapadj) * 12) + 373) / 367);
 184    day = (int32_t)(wjd - gregorianToJD(year, month, 1)) + 1;
 185
 186    gregorianDate[0] = year;
 187    gregorianDate[1] = month;
 188    gregorianDate[2] = day;
 189
 190    return gregorianDate;
 191 }
 192
 193
 194 //-------------------------------------------------------------------------
 195 // Functions for converting from field values to milliseconds....
 196 //-------------------------------------------------------------------------
 197 static double IndianToJD(int32_t year, int32_t month, int32_t date) {
 198    int32_t leapMonth, gyear, m;
 199    double start, jd;
 200
 201    gyear = year + INDIAN_ERA_START;
 202
 203
 204    if(isGregorianLeap(gyear)) {
 205       leapMonth = 31;
 206       start = gregorianToJD(gyear, 3, 21);
 207    }
 208    else {
 209       leapMonth = 30;
 210       start = gregorianToJD(gyear, 3, 22);
 211    }
 212
 213    if (month == 1) {
 214       jd = start + (date - 1);
 215    } else {
 216       jd = start + leapMonth;
 217       m = month - 2;
 218
 219       //m = Math.min(m, 5);
 220       if (m > 5) {
 221           m = 5;
 222       }
 223
 224       jd += m * 31;
 225
 226       if (month >= 8) {
 227          m = month - 7;
 228          jd += m * 30;
 229       }
 230       jd += date - 1;
 231    }
 232
 233    return jd;
 234 }
 235
 236 /*
 237  * Return JD of start of given month/year of Indian Calendar
 238  * @param eyear The year in Indian Calendar measured from Saka Era (78 AD).
 239  * @param month The month in Indian calendar
 240  */
 241 int32_t IndianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */ ) const {
 242
 243    //month is 0 based; converting it to 1-based
 244    int32_t imonth;
 245
 246     // If the month is out of range, adjust it into range, and adjust the extended eyar accordingly
 247    if (month < 0 || month > 11) {
 248       eyear += (int32_t)ClockMath::floorDivide(month, 12, month);
 249    }
 250
 251    if(month == 12){
 252        imonth = 1;
 253    } else {
 254        imonth = month + 1;
 255    }
 256
 257    double jd = IndianToJD(eyear ,imonth, 1);
 258
 259    return (int32_t)jd;
 260 }
 261
 262 //-------------------------------------------------------------------------
 263 // Functions for converting from milliseconds to field values
 264 //-------------------------------------------------------------------------
 265
 266 int32_t IndianCalendar::handleGetExtendedYear() {
 267     int32_t year;
 268
 269     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
 270         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
 271     } else {
 272         year = internalGet(UCAL_YEAR, 1); // Default to year 1
 273     }
 274
 275     return year;
 276 }
 277
 278 /*
 279  * Override Calendar to compute several fields specific to the Indian
 280  * calendar system.  These are:
 281  *
 282  * <ul><li>ERA
 283  * <li>YEAR
 284  * <li>MONTH
 285  * <li>DAY_OF_MONTH
 286  * <li>EXTENDED_YEAR</ul>
 287  *
 288  * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
 289  * method is called. The getGregorianXxx() methods return Gregorian
 290  * calendar equivalents for the given Julian day.
 291  */
 292 void IndianCalendar::handleComputeFields(int32_t julianDay, UErrorCode&  /* status */) {
 293     double jdAtStartOfGregYear;
 294     int32_t leapMonth, IndianYear, yday, IndianMonth, IndianDayOfMonth, mday;
 295     int32_t gregorianYear;      // Stores gregorian date corresponding to Julian day;
 296     int32_t gd[3];
 297
 298     gregorianYear = jdToGregorian(julianDay, gd)[0];          // Gregorian date for Julian day
 299     IndianYear = gregorianYear - INDIAN_ERA_START;            // Year in Saka era
 300     jdAtStartOfGregYear = gregorianToJD(gregorianYear, 1, 1); // JD at start of Gregorian year
 301     yday = (int32_t)(julianDay - jdAtStartOfGregYear);        // Day number in Gregorian year (starting from 0)
 302
 303     if (yday < INDIAN_YEAR_START) {
 304         // Day is at the end of the preceding Saka year
 305         IndianYear -= 1;
 306         leapMonth = isGregorianLeap(gregorianYear - 1) ? 31 : 30; // Days in leapMonth this year, previous Gregorian year
 307         yday += leapMonth + (31 * 5) + (30 * 3) + 10;
 308     } else {
 309         leapMonth = isGregorianLeap(gregorianYear) ? 31 : 30; // Days in leapMonth this year
 310         yday -= INDIAN_YEAR_START;
 311     }
 312
 313     if (yday < leapMonth) {
 314         IndianMonth = 0;
 315         IndianDayOfMonth = yday + 1;
 316     } else {
 317         mday = yday - leapMonth;
 318         if (mday < (31 * 5)) {
 319             IndianMonth = (int32_t)uprv_floor(mday / 31) + 1;
 320             IndianDayOfMonth = (mday % 31) + 1;
 321         } else {
 322             mday -= 31 * 5;
 323             IndianMonth = (int32_t)uprv_floor(mday / 30) + 6;
 324             IndianDayOfMonth = (mday % 30) + 1;
 325         }
 326    }
 327
 328    internalSet(UCAL_ERA, 0);
 329    internalSet(UCAL_EXTENDED_YEAR, IndianYear);
 330    internalSet(UCAL_YEAR, IndianYear);
 331    internalSet(UCAL_MONTH, IndianMonth);
 332    internalSet(UCAL_DAY_OF_MONTH, IndianDayOfMonth);
 333    internalSet(UCAL_DAY_OF_YEAR, yday + 1); // yday is 0-based
 334 }
 335
 336 UBool
 337 IndianCalendar::inDaylightTime(UErrorCode& status) const
 338 {
 339     // copied from GregorianCalendar
 340     if (U_FAILURE(status) || !getTimeZone().useDaylightTime()) {
 341         return FALSE;
 342     }
 343
 344     // Force an update of the state of the Calendar.
 345     ((IndianCalendar*)this)->complete(status); // cast away const
 346
 347     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
 348 }
 349
 350 // default century
 351 const UDate     IndianCalendar::fgSystemDefaultCentury          = DBL_MIN;
 352 const int32_t   IndianCalendar::fgSystemDefaultCenturyYear      = -1;
 353
 354 UDate           IndianCalendar::fgSystemDefaultCenturyStart     = DBL_MIN;
 355 int32_t         IndianCalendar::fgSystemDefaultCenturyStartYear = -1;
 356
 357
 358 UBool IndianCalendar::haveDefaultCentury() const
 359 {
 360     return TRUE;
 361 }
 362
 363 UDate IndianCalendar::defaultCenturyStart() const
 364 {
 365     return internalGetDefaultCenturyStart();
 366 }
 367
 368 int32_t IndianCalendar::defaultCenturyStartYear() const
 369 {
 370     return internalGetDefaultCenturyStartYear();
 371 }
 372
 373 UDate
 374 IndianCalendar::internalGetDefaultCenturyStart() const
 375 {
 376     // lazy-evaluate systemDefaultCenturyStart
 377     UBool needsUpdate;
 378     {
 379         Mutex m;
 380         needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
 381     }
 382
 383     if (needsUpdate) {
 384         initializeSystemDefaultCentury();
 385     }
 386
 387     // use defaultCenturyStart unless it's the flag value;
 388     // then use systemDefaultCenturyStart
 389
 390     return fgSystemDefaultCenturyStart;
 391 }
 392
 393 int32_t
 394 IndianCalendar::internalGetDefaultCenturyStartYear() const
 395 {
 396     // lazy-evaluate systemDefaultCenturyStartYear
 397     UBool needsUpdate;
 398     {
 399         Mutex m;
 400
 401         needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
 402     }
 403
 404     if (needsUpdate) {
 405         initializeSystemDefaultCentury();
 406     }
 407
 408     // use defaultCenturyStart unless it's the flag value;
 409     // then use systemDefaultCenturyStartYear
 410
 411     return    fgSystemDefaultCenturyStartYear;
 412 }
 413
 414 void
 415 IndianCalendar::initializeSystemDefaultCentury()
 416 {
 417     // initialize systemDefaultCentury and systemDefaultCenturyYear based
 418     // on the current time.  They'll be set to 80 years before
 419     // the current time.
 420     // No point in locking as it should be idempotent.
 421     if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury) {
 422         UErrorCode status = U_ZERO_ERROR;
 423
 424         IndianCalendar calendar(Locale("@calendar=Indian"),status);
 425         if (U_SUCCESS(status)) {
 426             calendar.setTime(Calendar::getNow(), status);
 427             calendar.add(UCAL_YEAR, -80, status);
 428
 429             UDate    newStart = calendar.getTime(status);
 430             int32_t  newYear  = calendar.get(UCAL_YEAR, status);
 431
 432             {
 433                 Mutex m;
 434
 435                 fgSystemDefaultCenturyStart = newStart;
 436                 fgSystemDefaultCenturyStartYear = newYear;
 437             }
 438         }
 439
 440         // We have no recourse upon failure unless we want to propagate the failure
 441         // out.
 442     }
 443 }
 444
 445 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IndianCalendar)
 446
 447 U_NAMESPACE_END
 448
 449 #endif
 450