icuSources/i18n/hebrwcal.cpp

   1 /*
   2 ******************************************************************************
   3 * Copyright (C) 2003-2008, International Business Machines Corporation
   4 * and others. All Rights Reserved.
   5 ******************************************************************************
   6 *
   7 * File HEBRWCAL.CPP
   8 *
   9 * Modification History:
  10 *
  11 *   Date        Name        Description
  12 *   12/03/2003  srl         ported from java HebrewCalendar
  13 *****************************************************************************
  14 */
  15
  16 #include "hebrwcal.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 // Hebrew Calendar implementation
  28
  29 /**
  30 * The absolute date, in milliseconds since 1/1/1970 AD, Gregorian,
  31 * of the start of the Hebrew calendar.  In order to keep this calendar's
  32 * time of day in sync with that of the Gregorian calendar, we use
  33 * midnight, rather than sunset the day before.
  34 */
  35 //static const double EPOCH_MILLIS = -180799862400000.; // 1/1/1 HY
  36
  37 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
  38     // Minimum  Greatest    Least  Maximum
  39     //           Minimum  Maximum
  40     {        0,        0,        0,        0}, // ERA
  41     { -5000000, -5000000,  5000000,  5000000}, // YEAR
  42     {        0,        0,       12,       12}, // MONTH
  43     {        1,        1,       51,       56}, // WEEK_OF_YEAR
  44     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
  45     {        1,        1,       29,       30}, // DAY_OF_MONTH
  46     {        1,        1,      353,      385}, // DAY_OF_YEAR
  47     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
  48     {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
  49     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
  50     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
  51     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
  52     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
  53     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
  54     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
  55     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
  56     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
  57     { -5000000, -5000000,  5000000,  5000000}, // YEAR_WOY
  58     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
  59     { -5000000, -5000000,  5000000,  5000000}, // EXTENDED_YEAR
  60     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
  61     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
  62     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
  63 };
  64
  65 /**
  66 * The lengths of the Hebrew months.  This is complicated, because there
  67 * are three different types of years, or six if you count leap years.
  68 * Due to the rules for postponing the start of the year to avoid having
  69 * certain holidays fall on the sabbath, the year can end up being three
  70 * different lengths, called "deficient", "normal", and "complete".
  71 */
  72 static const int8_t MONTH_LENGTH[][3] = {
  73     // Deficient  Normal     Complete
  74     {   30,         30,         30     },           //Tishri
  75     {   29,         29,         30     },           //Heshvan
  76     {   29,         30,         30     },           //Kislev
  77     {   29,         29,         29     },           //Tevet
  78     {   30,         30,         30     },           //Shevat
  79     {   30,         30,         30     },           //Adar I (leap years only)
  80     {   29,         29,         29     },           //Adar
  81     {   30,         30,         30     },           //Nisan
  82     {   29,         29,         29     },           //Iyar
  83     {   30,         30,         30     },           //Sivan
  84     {   29,         29,         29     },           //Tammuz
  85     {   30,         30,         30     },           //Av
  86     {   29,         29,         29     },           //Elul
  87 };
  88
  89 /**
  90 * The cumulative # of days to the end of each month in a non-leap year
  91 * Although this can be calculated from the MONTH_LENGTH table,
  92 * keeping it around separately makes some calculations a lot faster
  93 */
  94
  95 static const int16_t MONTH_START[][3] = {
  96     // Deficient  Normal     Complete
  97     {    0,          0,          0  },          // (placeholder)
  98     {   30,         30,         30  },          // Tishri
  99     {   59,         59,         60  },          // Heshvan
 100     {   88,         89,         90  },          // Kislev
 101     {  117,        118,        119  },          // Tevet
 102     {  147,        148,        149  },          // Shevat
 103     {  147,        148,        149  },          // (Adar I placeholder)
 104     {  176,        177,        178  },          // Adar
 105     {  206,        207,        208  },          // Nisan
 106     {  235,        236,        237  },          // Iyar
 107     {  265,        266,        267  },          // Sivan
 108     {  294,        295,        296  },          // Tammuz
 109     {  324,        325,        326  },          // Av
 110     {  353,        354,        355  },          // Elul
 111 };
 112
 113 /**
 114 * The cumulative # of days to the end of each month in a leap year
 115 */
 116 static const int16_t  LEAP_MONTH_START[][3] = {
 117     // Deficient  Normal     Complete
 118     {    0,          0,          0  },          // (placeholder)
 119     {   30,         30,         30  },          // Tishri
 120     {   59,         59,         60  },          // Heshvan
 121     {   88,         89,         90  },          // Kislev
 122     {  117,        118,        119  },          // Tevet
 123     {  147,        148,        149  },          // Shevat
 124     {  177,        178,        179  },          // Adar I
 125     {  206,        207,        208  },          // Adar II
 126     {  236,        237,        238  },          // Nisan
 127     {  265,        266,        267  },          // Iyar
 128     {  295,        296,        297  },          // Sivan
 129     {  324,        325,        326  },          // Tammuz
 130     {  354,        355,        356  },          // Av
 131     {  383,        384,        385  },          // Elul
 132 };
 133
 134 static U_NAMESPACE_QUALIFIER CalendarCache *gCache =  NULL;
 135
 136 U_CDECL_BEGIN
 137 static UBool calendar_hebrew_cleanup(void) {
 138     delete gCache;
 139     gCache = NULL;
 140     return TRUE;
 141 }
 142 U_CDECL_END
 143
 144 U_NAMESPACE_BEGIN
 145 //-------------------------------------------------------------------------
 146 // Constructors...
 147 //-------------------------------------------------------------------------
 148
 149 /**
 150 * Constructs a default <code>HebrewCalendar</code> using the current time
 151 * in the default time zone with the default locale.
 152 * @internal
 153 */
 154 HebrewCalendar::HebrewCalendar(const Locale& aLocale, UErrorCode& success)
 155 :   Calendar(TimeZone::createDefault(), aLocale, success)
 156
 157 {
 158     setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
 159 }
 160
 161
 162 HebrewCalendar::~HebrewCalendar() {
 163 }
 164
 165 const char *HebrewCalendar::getType() const {
 166     return "hebrew";
 167 }
 168
 169 Calendar* HebrewCalendar::clone() const {
 170     return new HebrewCalendar(*this);
 171 }
 172
 173 HebrewCalendar::HebrewCalendar(const HebrewCalendar& other) : Calendar(other) {
 174 }
 175
 176
 177 //-------------------------------------------------------------------------
 178 // Rolling and adding functions overridden from Calendar
 179 //
 180 // These methods call through to the default implementation in IBMCalendar
 181 // for most of the fields and only handle the unusual ones themselves.
 182 //-------------------------------------------------------------------------
 183
 184 /**
 185 * Add a signed amount to a specified field, using this calendar's rules.
 186 * For example, to add three days to the current date, you can call
 187 * <code>add(Calendar.DATE, 3)</code>.
 188 * <p>
 189 * When adding to certain fields, the values of other fields may conflict and
 190 * need to be changed.  For example, when adding one to the {@link #MONTH MONTH} field
 191 * for the date "30 Av 5758", the {@link #DAY_OF_MONTH DAY_OF_MONTH} field
 192 * must be adjusted so that the result is "29 Elul 5758" rather than the invalid
 193 * "30 Elul 5758".
 194 * <p>
 195 * This method is able to add to
 196 * all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET},
 197 * and {@link #ZONE_OFFSET ZONE_OFFSET}.
 198 * <p>
 199 * <b>Note:</b> You should always use {@link #roll roll} and add rather
 200 * than attempting to perform arithmetic operations directly on the fields
 201 * of a <tt>HebrewCalendar</tt>.  Since the {@link #MONTH MONTH} field behaves
 202 * discontinuously in non-leap years, simple arithmetic can give invalid results.
 203 * <p>
 204 * @param field     the time field.
 205 * @param amount    the amount to add to the field.
 206 *
 207 * @exception   IllegalArgumentException if the field is invalid or refers
 208 *              to a field that cannot be handled by this method.
 209 * @internal
 210 */
 211 void HebrewCalendar::add(UCalendarDateFields field, int32_t amount, UErrorCode& status)
 212 {
 213     if(U_FAILURE(status)) {
 214         return;
 215     }
 216     switch (field) {
 217   case UCAL_MONTH:
 218       {
 219           // We can't just do a set(MONTH, get(MONTH) + amount).  The
 220           // reason is ADAR_1.  Suppose amount is +2 and we land in
 221           // ADAR_1 -- then we have to bump to ADAR_2 aka ADAR.  But
 222           // if amount is -2 and we land in ADAR_1, then we have to
 223           // bump the other way -- down to SHEVAT.  - Alan 11/00
 224           int32_t month = get(UCAL_MONTH, status);
 225           int32_t year = get(UCAL_YEAR, status);
 226           UBool acrossAdar1;
 227           if (amount > 0) {
 228               acrossAdar1 = (month < ADAR_1); // started before ADAR_1?
 229               month += amount;
 230               for (;;) {
 231                   if (acrossAdar1 && month>=ADAR_1 && !isLeapYear(year)) {
 232                       ++month;
 233                   }
 234                   if (month <= ELUL) {
 235                       break;
 236                   }
 237                   month -= ELUL+1;
 238                   ++year;
 239                   acrossAdar1 = TRUE;
 240               }
 241           } else {
 242               acrossAdar1 = (month > ADAR_1); // started after ADAR_1?
 243               month += amount;
 244               for (;;) {
 245                   if (acrossAdar1 && month<=ADAR_1 && !isLeapYear(year)) {
 246                       --month;
 247                   }
 248                   if (month >= 0) {
 249                       break;
 250                   }
 251                   month += ELUL+1;
 252                   --year;
 253                   acrossAdar1 = TRUE;
 254               }
 255           }
 256           set(UCAL_MONTH, month);
 257           set(UCAL_YEAR, year);
 258           pinField(UCAL_DAY_OF_MONTH, status);
 259           break;
 260       }
 261
 262   default:
 263       Calendar::add(field, amount, status);
 264       break;
 265     }
 266 }
 267
 268 /**
 269 * @deprecated ICU 2.6 use UCalendarDateFields instead of EDateFields
 270 */
 271 void HebrewCalendar::add(EDateFields field, int32_t amount, UErrorCode& status)
 272 {
 273     add((UCalendarDateFields)field, amount, status);
 274 }
 275
 276 /**
 277 * Rolls (up/down) a specified amount time on the given field.  For
 278 * example, to roll the current date up by three days, you can call
 279 * <code>roll(Calendar.DATE, 3)</code>.  If the
 280 * field is rolled past its maximum allowable value, it will "wrap" back
 281 * to its minimum and continue rolling.
 282 * For example, calling <code>roll(Calendar.DATE, 10)</code>
 283 * on a Hebrew calendar set to "25 Av 5758" will result in the date "5 Av 5758".
 284 * <p>
 285 * When rolling certain fields, the values of other fields may conflict and
 286 * need to be changed.  For example, when rolling the {@link #MONTH MONTH} field
 287 * upward by one for the date "30 Av 5758", the {@link #DAY_OF_MONTH DAY_OF_MONTH} field
 288 * must be adjusted so that the result is "29 Elul 5758" rather than the invalid
 289 * "30 Elul".
 290 * <p>
 291 * This method is able to roll
 292 * all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET},
 293 * and {@link #ZONE_OFFSET ZONE_OFFSET}.  Subclasses may, of course, add support for
 294 * additional fields in their overrides of <code>roll</code>.
 295 * <p>
 296 * <b>Note:</b> You should always use roll and {@link #add add} rather
 297 * than attempting to perform arithmetic operations directly on the fields
 298 * of a <tt>HebrewCalendar</tt>.  Since the {@link #MONTH MONTH} field behaves
 299 * discontinuously in non-leap years, simple arithmetic can give invalid results.
 300 * <p>
 301 * @param field     the time field.
 302 * @param amount    the amount by which the field should be rolled.
 303 *
 304 * @exception   IllegalArgumentException if the field is invalid or refers
 305 *              to a field that cannot be handled by this method.
 306 * @internal
 307 */
 308 void HebrewCalendar::roll(UCalendarDateFields field, int32_t amount, UErrorCode& status)
 309 {
 310     if(U_FAILURE(status)) {
 311         return;
 312     }
 313     switch (field) {
 314   case UCAL_MONTH:
 315       {
 316           int32_t month = get(UCAL_MONTH, status);
 317           int32_t year = get(UCAL_YEAR, status);
 318
 319           UBool leapYear = isLeapYear(year);
 320           int32_t yearLength = monthsInYear(year);
 321           int32_t newMonth = month + (amount % yearLength);
 322           //
 323           // If it's not a leap year and we're rolling past the missing month
 324           // of ADAR_1, we need to roll an extra month to make up for it.
 325           //
 326           if (!leapYear) {
 327               if (amount > 0 && month < ADAR_1 && newMonth >= ADAR_1) {
 328                   newMonth++;
 329               } else if (amount < 0 && month > ADAR_1 && newMonth <= ADAR_1) {
 330                   newMonth--;
 331               }
 332           }
 333           set(UCAL_MONTH, (newMonth + 13) % 13);
 334           pinField(UCAL_DAY_OF_MONTH, status);
 335           return;
 336       }
 337   default:
 338       Calendar::roll(field, amount, status);
 339     }
 340 }
 341
 342 void HebrewCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) {
 343     roll((UCalendarDateFields)field, amount, status);
 344 }
 345
 346 //-------------------------------------------------------------------------
 347 // Support methods
 348 //-------------------------------------------------------------------------
 349
 350 // Hebrew date calculations are performed in terms of days, hours, and
 351 // "parts" (or halakim), which are 1/1080 of an hour, or 3 1/3 seconds.
 352 static const int32_t HOUR_PARTS = 1080;
 353 static const int32_t DAY_PARTS  = 24*HOUR_PARTS;
 354
 355 // An approximate value for the length of a lunar month.
 356 // It is used to calculate the approximate year and month of a given
 357 // absolute date.
 358 static const int32_t  MONTH_DAYS = 29;
 359 static const int32_t MONTH_FRACT = 12*HOUR_PARTS + 793;
 360 static const int32_t MONTH_PARTS = MONTH_DAYS*DAY_PARTS + MONTH_FRACT;
 361
 362 // The time of the new moon (in parts) on 1 Tishri, year 1 (the epoch)
 363 // counting from noon on the day before.  BAHARAD is an abbreviation of
 364 // Bet (Monday), Hey (5 hours from sunset), Resh-Daled (204).
 365 static const int32_t BAHARAD = 11*HOUR_PARTS + 204;
 366
 367 /**
 368 * Finds the day # of the first day in the given Hebrew year.
 369 * To do this, we want to calculate the time of the Tishri 1 new moon
 370 * in that year.
 371 * <p>
 372 * The algorithm here is similar to ones described in a number of
 373 * references, including:
 374 * <ul>
 375 * <li>"Calendrical Calculations", by Nachum Dershowitz & Edward Reingold,
 376 *     Cambridge University Press, 1997, pages 85-91.
 377 *
 378 * <li>Hebrew Calendar Science and Myths,
 379 *     <a href="http://www.geocities.com/Athens/1584/">
 380 *     http://www.geocities.com/Athens/1584/</a>
 381 *
 382 * <li>The Calendar FAQ,
 383 *      <a href="http://www.faqs.org/faqs/calendars/faq/">
 384 *      http://www.faqs.org/faqs/calendars/faq/</a>
 385 * </ul>
 386 */
 387 int32_t HebrewCalendar::startOfYear(int32_t year, UErrorCode &status)
 388 {
 389     ucln_i18n_registerCleanup(UCLN_I18N_HEBREW_CALENDAR, calendar_hebrew_cleanup);
 390     int32_t day = CalendarCache::get(&gCache, year, status);
 391
 392     if (day == 0) {
 393         int32_t months = (235 * year - 234) / 19;           // # of months before year
 394
 395         int64_t frac = (int64_t)months * MONTH_FRACT + BAHARAD;  // Fractional part of day #
 396         day  = months * 29 + (int32_t)(frac / DAY_PARTS);        // Whole # part of calculation
 397         frac = frac % DAY_PARTS;                        // Time of day
 398
 399         int32_t wd = (day % 7);                        // Day of week (0 == Monday)
 400
 401         if (wd == 2 || wd == 4 || wd == 6) {
 402             // If the 1st is on Sun, Wed, or Fri, postpone to the next day
 403             day += 1;
 404             wd = (day % 7);
 405         }
 406         if (wd == 1 && frac > 15*HOUR_PARTS+204 && !isLeapYear(year) ) {
 407             // If the new moon falls after 3:11:20am (15h204p from the previous noon)
 408             // on a Tuesday and it is not a leap year, postpone by 2 days.
 409             // This prevents 356-day years.
 410             day += 2;
 411         }
 412         else if (wd == 0 && frac > 21*HOUR_PARTS+589 && isLeapYear(year-1) ) {
 413             // If the new moon falls after 9:32:43 1/3am (21h589p from yesterday noon)
 414             // on a Monday and *last* year was a leap year, postpone by 1 day.
 415             // Prevents 382-day years.
 416             day += 1;
 417         }
 418         CalendarCache::put(&gCache, year, day, status);
 419     }
 420     return day;
 421 }
 422
 423 /**
 424 * Find the day of the week for a given day
 425 *
 426 * @param day   The # of days since the start of the Hebrew calendar,
 427 *              1-based (i.e. 1/1/1 AM is day 1).
 428 */
 429 int32_t HebrewCalendar::absoluteDayToDayOfWeek(int32_t day)
 430 {
 431     // We know that 1/1/1 AM is a Monday, which makes the math easy...
 432     return (day % 7) + 1;
 433 }
 434
 435 /**
 436 * Returns the the type of a given year.
 437 *  0   "Deficient" year with 353 or 383 days
 438 *  1   "Normal"    year with 354 or 384 days
 439 *  2   "Complete"  year with 355 or 385 days
 440 */
 441 int32_t HebrewCalendar::yearType(int32_t year) const
 442 {
 443     int32_t yearLength = handleGetYearLength(year);
 444
 445     if (yearLength > 380) {
 446         yearLength -= 30;        // Subtract length of leap month.
 447     }
 448
 449     int type = 0;
 450
 451     switch (yearLength) {
 452   case 353:
 453       type = 0; break;
 454   case 354:
 455       type = 1; break;
 456   case 355:
 457       type = 2; break;
 458   default:
 459       //throw new RuntimeException("Illegal year length " + yearLength + " in year " + year);
 460       type = 1;
 461     }
 462     return type;
 463 }
 464
 465 /**
 466 * Determine whether a given Hebrew year is a leap year
 467 *
 468 * The rule here is that if (year % 19) == 0, 3, 6, 8, 11, 14, or 17.
 469 * The formula below performs the same test, believe it or not.
 470 */
 471 UBool HebrewCalendar::isLeapYear(int32_t year) {
 472     //return (year * 12 + 17) % 19 >= 12;
 473     int32_t x = (year*12 + 17) % 19;
 474     return x >= ((x < 0) ? -7 : 12);
 475 }
 476
 477 int32_t HebrewCalendar::monthsInYear(int32_t year) {
 478     return isLeapYear(year) ? 13 : 12;
 479 }
 480
 481 //-------------------------------------------------------------------------
 482 // Calendar framework
 483 //-------------------------------------------------------------------------
 484
 485 /**
 486 * @internal
 487 */
 488 int32_t HebrewCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
 489     return LIMITS[field][limitType];
 490 }
 491
 492 /**
 493 * Returns the length of the given month in the given year
 494 * @internal
 495 */
 496 int32_t HebrewCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
 497     // Resolve out-of-range months.  This is necessary in order to
 498     // obtain the correct year.  We correct to
 499     // a 12- or 13-month year (add/subtract 12 or 13, depending
 500     // on the year) but since we _always_ number from 0..12, and
 501     // the leap year determines whether or not month 5 (Adar 1)
 502     // is present, we allow 0..12 in any given year.
 503     while (month < 0) {
 504         month += monthsInYear(--extendedYear);
 505     }
 506     // Careful: allow 0..12 in all years
 507     while (month > 12) {
 508         month -= monthsInYear(extendedYear++);
 509     }
 510
 511     switch (month) {
 512     case HESHVAN:
 513     case KISLEV:
 514       // These two month lengths can vary
 515       return MONTH_LENGTH[month][yearType(extendedYear)];
 516
 517     default:
 518       // The rest are a fixed length
 519       return MONTH_LENGTH[month][0];
 520     }
 521 }
 522
 523 /**
 524 * Returns the number of days in the given Hebrew year
 525 * @internal
 526 */
 527 int32_t HebrewCalendar::handleGetYearLength(int32_t eyear) const {
 528     UErrorCode status = U_ZERO_ERROR;
 529     return startOfYear(eyear+1, status) - startOfYear(eyear, status);
 530 }
 531
 532 //-------------------------------------------------------------------------
 533 // Functions for converting from milliseconds to field values
 534 //-------------------------------------------------------------------------
 535
 536 /**
 537 * Subclasses may override this method to compute several fields
 538 * specific to each calendar system.  These are:
 539 *
 540 * <ul><li>ERA
 541 * <li>YEAR
 542 * <li>MONTH
 543 * <li>DAY_OF_MONTH
 544 * <li>DAY_OF_YEAR
 545 * <li>EXTENDED_YEAR</ul>
 546 *
 547 * Subclasses can refer to the DAY_OF_WEEK and DOW_LOCAL fields,
 548 * which will be set when this method is called.  Subclasses can
 549 * also call the getGregorianXxx() methods to obtain Gregorian
 550 * calendar equivalents for the given Julian day.
 551 *
 552 * <p>In addition, subclasses should compute any subclass-specific
 553 * fields, that is, fields from BASE_FIELD_COUNT to
 554 * getFieldCount() - 1.
 555 * @internal
 556 */
 557 void HebrewCalendar::handleComputeFields(int32_t julianDay, UErrorCode &status) {
 558     int32_t d = julianDay - 347997;
 559     double m = ((d * (double)DAY_PARTS)/ (double) MONTH_PARTS);         // Months (approx)
 560     int32_t year = (int32_t)( ((19. * m + 234.) / 235.) + 1.);     // Years (approx)
 561     int32_t ys  = startOfYear(year, status);                   // 1st day of year
 562     int32_t dayOfYear = (d - ys);
 563
 564     // Because of the postponement rules, it's possible to guess wrong.  Fix it.
 565     while (dayOfYear < 1) {
 566         year--;
 567         ys  = startOfYear(year, status);
 568         dayOfYear = (d - ys);
 569     }
 570
 571     // Now figure out which month we're in, and the date within that month
 572     int32_t type = yearType(year);
 573     UBool isLeap = isLeapYear(year);
 574
 575     int32_t month = 0;
 576     int32_t momax = sizeof(MONTH_START) / (3 * sizeof(MONTH_START[0][0]));
 577     while (month < momax && dayOfYear > (  isLeap ? LEAP_MONTH_START[month][type] : MONTH_START[month][type] ) ) {
 578         month++;
 579     }
 580     if (month >= momax || month<=0) {
 581         // TODO: I found dayOfYear could be out of range when
 582         // a large value is set to julianDay.  I patched startOfYear
 583         // to reduce the chace, but it could be still reproduced either
 584         // by startOfYear or other places.  For now, we check
 585         // the month is in valid range to avoid out of array index
 586         // access problem here.  However, we need to carefully review
 587         // the calendar implementation to check the extreme limit of
 588         // each calendar field and the code works well for any values
 589         // in the valid value range.  -yoshito
 590         status = U_ILLEGAL_ARGUMENT_ERROR;
 591         return;
 592     }
 593     month--;
 594     int dayOfMonth = dayOfYear - (isLeap ? LEAP_MONTH_START[month][type] : MONTH_START[month][type]);
 595
 596     internalSet(UCAL_ERA, 0);
 597     internalSet(UCAL_YEAR, year);
 598     internalSet(UCAL_EXTENDED_YEAR, year);
 599     internalSet(UCAL_MONTH, month);
 600     internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
 601     internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
 602 }
 603
 604 //-------------------------------------------------------------------------
 605 // Functions for converting from field values to milliseconds
 606 //-------------------------------------------------------------------------
 607
 608 /**
 609 * @internal
 610 */
 611 int32_t HebrewCalendar::handleGetExtendedYear() {
 612     int32_t year;
 613     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
 614         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
 615     } else {
 616         year = internalGet(UCAL_YEAR, 1); // Default to year 1
 617     }
 618     return year;
 619 }
 620
 621 /**
 622 * Return JD of start of given month/year.
 623 * @internal
 624 */
 625 int32_t HebrewCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /*useMonth*/) const {
 626     UErrorCode status = U_ZERO_ERROR;
 627     // Resolve out-of-range months.  This is necessary in order to
 628     // obtain the correct year.  We correct to
 629     // a 12- or 13-month year (add/subtract 12 or 13, depending
 630     // on the year) but since we _always_ number from 0..12, and
 631     // the leap year determines whether or not month 5 (Adar 1)
 632     // is present, we allow 0..12 in any given year.
 633     while (month < 0) {
 634         month += monthsInYear(--eyear);
 635     }
 636     // Careful: allow 0..12 in all years
 637     while (month > 12) {
 638         month -= monthsInYear(eyear++);
 639     }
 640
 641     int32_t day = startOfYear(eyear, status);
 642
 643     if(U_FAILURE(status)) {
 644         return 0;
 645     }
 646
 647     if (month != 0) {
 648         if (isLeapYear(eyear)) {
 649             day += LEAP_MONTH_START[month][yearType(eyear)];
 650         } else {
 651             day += MONTH_START[month][yearType(eyear)];
 652         }
 653     }
 654
 655     return (int) (day + 347997);
 656 }
 657
 658 UBool
 659 HebrewCalendar::inDaylightTime(UErrorCode& status) const
 660 {
 661     // copied from GregorianCalendar
 662     if (U_FAILURE(status) || !getTimeZone().useDaylightTime())
 663         return FALSE;
 664
 665     // Force an update of the state of the Calendar.
 666     ((HebrewCalendar*)this)->complete(status); // cast away const
 667
 668     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
 669 }
 670
 671 // default century
 672 const UDate     HebrewCalendar::fgSystemDefaultCentury        = DBL_MIN;
 673 const int32_t   HebrewCalendar::fgSystemDefaultCenturyYear    = -1;
 674
 675 UDate           HebrewCalendar::fgSystemDefaultCenturyStart       = DBL_MIN;
 676 int32_t         HebrewCalendar::fgSystemDefaultCenturyStartYear   = -1;
 677
 678
 679 UBool HebrewCalendar::haveDefaultCentury() const
 680 {
 681     return TRUE;
 682 }
 683
 684 UDate HebrewCalendar::defaultCenturyStart() const
 685 {
 686     return internalGetDefaultCenturyStart();
 687 }
 688
 689 int32_t HebrewCalendar::defaultCenturyStartYear() const
 690 {
 691     return internalGetDefaultCenturyStartYear();
 692 }
 693
 694 UDate
 695 HebrewCalendar::internalGetDefaultCenturyStart() const
 696 {
 697     // lazy-evaluate systemDefaultCenturyStart
 698     UBool needsUpdate;
 699     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
 700
 701     if (needsUpdate) {
 702         initializeSystemDefaultCentury();
 703     }
 704
 705     // use defaultCenturyStart unless it's the flag value;
 706     // then use systemDefaultCenturyStart
 707
 708     return fgSystemDefaultCenturyStart;
 709 }
 710
 711 int32_t
 712 HebrewCalendar::internalGetDefaultCenturyStartYear() const
 713 {
 714     // lazy-evaluate systemDefaultCenturyStartYear
 715     UBool needsUpdate;
 716     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
 717
 718     if (needsUpdate) {
 719         initializeSystemDefaultCentury();
 720     }
 721
 722     // use defaultCenturyStart unless it's the flag value;
 723     // then use systemDefaultCenturyStartYear
 724
 725     return fgSystemDefaultCenturyStartYear;
 726 }
 727
 728 void
 729 HebrewCalendar::initializeSystemDefaultCentury()
 730 {
 731     // initialize systemDefaultCentury and systemDefaultCenturyYear based
 732     // on the current time.  They'll be set to 80 years before
 733     // the current time.
 734     UErrorCode status = U_ZERO_ERROR;
 735     HebrewCalendar calendar(Locale("@calendar=hebrew"),status);
 736     if (U_SUCCESS(status))
 737     {
 738         calendar.setTime(Calendar::getNow(), status);
 739         calendar.add(UCAL_YEAR, -80, status);
 740         UDate    newStart =  calendar.getTime(status);
 741         int32_t  newYear  =  calendar.get(UCAL_YEAR, status);
 742         umtx_lock(NULL);
 743         if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury) {
 744             fgSystemDefaultCenturyStartYear = newYear;
 745             fgSystemDefaultCenturyStart = newStart;
 746         }
 747         umtx_unlock(NULL);
 748     }
 749     // We have no recourse upon failure unless we want to propagate the failure
 750     // out.
 751 }
 752
 753 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(HebrewCalendar)
 754
 755 U_NAMESPACE_END
 756
 757 #endif // UCONFIG_NO_FORMATTING
 758