intl/icu/source/i18n/hebrwcal.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Thu, 22 Jan 2015 13:21:57 +0100
branch
TOR_BUG_9701
changeset 15
b8a032363ba2
permissions
-rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /*
     2 ******************************************************************************
     3 * Copyright (C) 2003-2013, 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 */
    16 #include "hebrwcal.h"
    18 #if !UCONFIG_NO_FORMATTING
    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"
    27 // Hebrew Calendar implementation
    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
    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 };
    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 };
    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 */
    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 };
   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 };
   134 static icu::CalendarCache *gCache =  NULL;
   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
   144 U_NAMESPACE_BEGIN
   145 //-------------------------------------------------------------------------
   146 // Constructors...
   147 //-------------------------------------------------------------------------
   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)
   157 {
   158     setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
   159 }
   162 HebrewCalendar::~HebrewCalendar() {
   163 }
   165 const char *HebrewCalendar::getType() const {
   166     return "hebrew";
   167 }
   169 Calendar* HebrewCalendar::clone() const {
   170     return new HebrewCalendar(*this);
   171 }
   173 HebrewCalendar::HebrewCalendar(const HebrewCalendar& other) : Calendar(other) {
   174 }
   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 //-------------------------------------------------------------------------
   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       }
   262   default:
   263       Calendar::add(field, amount, status);
   264       break;
   265     }
   266 }
   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 }
   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);
   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 }
   342 void HebrewCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) {
   343     roll((UCalendarDateFields)field, amount, status);
   344 }
   346 //-------------------------------------------------------------------------
   347 // Support methods
   348 //-------------------------------------------------------------------------
   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;
   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;
   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;
   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);
   392     if (day == 0) {
   393         int32_t months = (235 * year - 234) / 19;           // # of months before year
   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
   399         int32_t wd = (day % 7);                        // Day of week (0 == Monday)
   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 }
   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 }
   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);
   445     if (yearLength > 380) {
   446         yearLength -= 30;        // Subtract length of leap month.
   447     }
   449     int type = 0;
   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 }
   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 }
   477 int32_t HebrewCalendar::monthsInYear(int32_t year) {
   478     return isLeapYear(year) ? 13 : 12;
   479 }
   481 //-------------------------------------------------------------------------
   482 // Calendar framework
   483 //-------------------------------------------------------------------------
   485 /**
   486 * @internal
   487 */
   488 int32_t HebrewCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
   489     return LIMITS[field][limitType];
   490 }
   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     }
   511     switch (month) {
   512     case HESHVAN:
   513     case KISLEV:
   514       // These two month lengths can vary
   515       return MONTH_LENGTH[month][yearType(extendedYear)];
   517     default:
   518       // The rest are a fixed length
   519       return MONTH_LENGTH[month][0];
   520     }
   521 }
   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 }
   532 //-------------------------------------------------------------------------
   533 // Functions for converting from milliseconds to field values
   534 //-------------------------------------------------------------------------
   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);
   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     }
   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);
   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]);
   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 }
   604 //-------------------------------------------------------------------------
   605 // Functions for converting from field values to milliseconds
   606 //-------------------------------------------------------------------------
   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 }
   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     }
   641     int32_t day = startOfYear(eyear, status);
   643     if(U_FAILURE(status)) {
   644         return 0;
   645     }
   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     }
   655     return (int) (day + 347997);
   656 }
   658 UBool
   659 HebrewCalendar::inDaylightTime(UErrorCode& status) const
   660 {
   661     // copied from GregorianCalendar
   662     if (U_FAILURE(status) || !getTimeZone().useDaylightTime()) 
   663         return FALSE;
   665     // Force an update of the state of the Calendar.
   666     ((HebrewCalendar*)this)->complete(status); // cast away const
   668     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
   669 }
   671 /**
   672  * The system maintains a static default century start date and Year.  They are
   673  * initialized the first time they are used.  Once the system default century date 
   674  * and year are set, they do not change.
   675  */
   676 static UDate           gSystemDefaultCenturyStart       = DBL_MIN;
   677 static int32_t         gSystemDefaultCenturyStartYear   = -1;
   678 static icu::UInitOnce  gSystemDefaultCenturyInit        = U_INITONCE_INITIALIZER;
   680 UBool HebrewCalendar::haveDefaultCentury() const
   681 {
   682     return TRUE;
   683 }
   685 static void U_CALLCONV initializeSystemDefaultCentury()
   686 {
   687     // initialize systemDefaultCentury and systemDefaultCenturyYear based
   688     // on the current time.  They'll be set to 80 years before
   689     // the current time.
   690     UErrorCode status = U_ZERO_ERROR;
   691     HebrewCalendar calendar(Locale("@calendar=hebrew"),status);
   692     if (U_SUCCESS(status)) {
   693         calendar.setTime(Calendar::getNow(), status);
   694         calendar.add(UCAL_YEAR, -80, status);
   696         gSystemDefaultCenturyStart = calendar.getTime(status);
   697         gSystemDefaultCenturyStartYear = calendar.get(UCAL_YEAR, status);
   698     }
   699     // We have no recourse upon failure unless we want to propagate the failure
   700     // out.
   701 }
   704 UDate HebrewCalendar::defaultCenturyStart() const {
   705     // lazy-evaluate systemDefaultCenturyStart
   706     umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
   707     return gSystemDefaultCenturyStart;
   708 }
   710 int32_t HebrewCalendar::defaultCenturyStartYear() const {
   711     // lazy-evaluate systemDefaultCenturyStartYear
   712     umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
   713     return gSystemDefaultCenturyStartYear;
   714 }
   717 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(HebrewCalendar)
   719 U_NAMESPACE_END
   721 #endif // UCONFIG_NO_FORMATTING

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