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      1 /*
      2  ******************************************************************************
      3  * Copyright (C) 2003-2013, International Business Machines Corporation
      4  * and others. All Rights Reserved.
      5  ******************************************************************************
      6  *
      7  * File PERSNCAL.CPP
      8  *
      9  * Modification History:
     10  *
     11  *   Date        Name        Description
     12  *   9/23/2003   mehran      posted to icu-design
     13  *   10/1/2012   roozbeh     Fixed algorithm and heavily refactored and rewrote
     14  *                           based on the implementation of Gregorian
     15  *****************************************************************************
     16  */
     17 
     18 #include "persncal.h"
     19 
     20 #if !UCONFIG_NO_FORMATTING
     21 
     22 #include "umutex.h"
     23 #include "gregoimp.h" // Math
     24 #include <float.h>
     25 
     26 static const int16_t kPersianNumDays[]
     27 = {0,31,62,93,124,155,186,216,246,276,306,336}; // 0-based, for day-in-year
     28 static const int8_t kPersianMonthLength[]
     29 = {31,31,31,31,31,31,30,30,30,30,30,29}; // 0-based
     30 static const int8_t kPersianLeapMonthLength[]
     31 = {31,31,31,31,31,31,30,30,30,30,30,30}; // 0-based
     32 
     33 static const int32_t kPersianCalendarLimits[UCAL_FIELD_COUNT][4] = {
     34     // Minimum  Greatest     Least   Maximum
     35     //           Minimum   Maximum
     36     {        0,        0,        0,        0}, // ERA
     37     { -5000000, -5000000,  5000000,  5000000}, // YEAR
     38     {        0,        0,       11,       11}, // MONTH
     39     {        1,        1,       52,       53}, // WEEK_OF_YEAR
     40     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
     41     {        1,       1,        29,       31}, // DAY_OF_MONTH
     42     {        1,       1,       365,      366}, // DAY_OF_YEAR
     43     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
     44     {        1,       1,         5,        5}, // DAY_OF_WEEK_IN_MONTH
     45     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
     46     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
     47     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
     48     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
     49     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
     50     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
     51     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
     52     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
     53     { -5000000, -5000000,  5000000,  5000000}, // YEAR_WOY
     54     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
     55     { -5000000, -5000000,  5000000,  5000000}, // EXTENDED_YEAR
     56     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
     57     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
     58     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
     59 };
     60 
     61 U_NAMESPACE_BEGIN
     62 
     63 static const int32_t PERSIAN_EPOCH = 1948320;
     64 
     65 // Implementation of the PersianCalendar class
     66 
     67 //-------------------------------------------------------------------------
     68 // Constructors...
     69 //-------------------------------------------------------------------------
     70 
     71 const char *PersianCalendar::getType() const {
     72     return "persian";
     73 }
     74 
     75 Calendar* PersianCalendar::clone() const {
     76     return new PersianCalendar(*this);
     77 }
     78 
     79 PersianCalendar::PersianCalendar(const Locale& aLocale, UErrorCode& success)
     80   :   Calendar(TimeZone::createDefault(), aLocale, success)
     81 {
     82     setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
     83 }
     84 
     85 PersianCalendar::PersianCalendar(const PersianCalendar& other) : Calendar(other) {
     86 }
     87 
     88 PersianCalendar::~PersianCalendar()
     89 {
     90 }
     91 
     92 //-------------------------------------------------------------------------
     93 // Minimum / Maximum access functions
     94 //-------------------------------------------------------------------------
     95 
     96 
     97 int32_t PersianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
     98     return kPersianCalendarLimits[field][limitType];
     99 }
    100 
    101 //-------------------------------------------------------------------------
    102 // Assorted calculation utilities
    103 //
    104 
    105 /**
    106  * Determine whether a year is a leap year in the Persian calendar
    107  */
    108 UBool PersianCalendar::isLeapYear(int32_t year)
    109 {
    110     int32_t remainder;
    111     ClockMath::floorDivide(25 * year + 11, 33, remainder);
    112     return (remainder < 8);
    113 }
    114 
    115 /**
    116  * Return the day # on which the given year starts.  Days are counted
    117  * from the Persian epoch, origin 0.
    118  */
    119 int32_t PersianCalendar::yearStart(int32_t year) {
    120     return handleComputeMonthStart(year,0,FALSE);
    121 }
    122 
    123 /**
    124  * Return the day # on which the given month starts.  Days are counted
    125  * from the Persian epoch, origin 0.
    126  *
    127  * @param year  The Persian year
    128  * @param year  The Persian month, 0-based
    129  */
    130 int32_t PersianCalendar::monthStart(int32_t year, int32_t month) const {
    131     return handleComputeMonthStart(year,month,TRUE);
    132 }
    133 
    134 //----------------------------------------------------------------------
    135 // Calendar framework
    136 //----------------------------------------------------------------------
    137 
    138 /**
    139  * Return the length (in days) of the given month.
    140  *
    141  * @param year  The Persian year
    142  * @param year  The Persian month, 0-based
    143  */
    144 int32_t PersianCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
    145     // If the month is out of range, adjust it into range, and
    146     // modify the extended year value accordingly.
    147     if (month < 0 || month > 11) {
    148         extendedYear += ClockMath::floorDivide(month, 12, month);
    149     }
    150 
    151     return isLeapYear(extendedYear) ? kPersianLeapMonthLength[month] : kPersianMonthLength[month];
    152 }
    153 
    154 /**
    155  * Return the number of days in the given Persian year
    156  */
    157 int32_t PersianCalendar::handleGetYearLength(int32_t extendedYear) const {
    158     return isLeapYear(extendedYear) ? 366 : 365;
    159 }
    160 
    161 //-------------------------------------------------------------------------
    162 // Functions for converting from field values to milliseconds....
    163 //-------------------------------------------------------------------------
    164 
    165 // Return JD of start of given month/year
    166 int32_t PersianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /*useMonth*/) const {
    167     // If the month is out of range, adjust it into range, and
    168     // modify the extended year value accordingly.
    169     if (month < 0 || month > 11) {
    170         eyear += ClockMath::floorDivide(month, 12, month);
    171     }
    172 
    173     int32_t julianDay = PERSIAN_EPOCH - 1 + 365 * (eyear - 1) + ClockMath::floorDivide(8 * eyear + 21, 33);
    174 
    175     if (month != 0) {
    176         julianDay += kPersianNumDays[month];
    177     }
    178 
    179     return julianDay;
    180 }
    181 
    182 //-------------------------------------------------------------------------
    183 // Functions for converting from milliseconds to field values
    184 //-------------------------------------------------------------------------
    185 
    186 int32_t PersianCalendar::handleGetExtendedYear() {
    187     int32_t year;
    188     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
    189         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
    190     } else {
    191         year = internalGet(UCAL_YEAR, 1); // Default to year 1
    192     }
    193     return year;
    194 }
    195 
    196 /**
    197  * Override Calendar to compute several fields specific to the Persian
    198  * calendar system.  These are:
    199  *
    200  * <ul><li>ERA
    201  * <li>YEAR
    202  * <li>MONTH
    203  * <li>DAY_OF_MONTH
    204  * <li>DAY_OF_YEAR
    205  * <li>EXTENDED_YEAR</ul>
    206  *
    207  * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
    208  * method is called.
    209  */
    210 void PersianCalendar::handleComputeFields(int32_t julianDay, UErrorCode &/*status*/) {
    211     int32_t year, month, dayOfMonth, dayOfYear;
    212 
    213     int32_t daysSinceEpoch = julianDay - PERSIAN_EPOCH;
    214     year = 1 + ClockMath::floorDivide(33 * daysSinceEpoch + 3, 12053);
    215 
    216     int32_t farvardin1 = 365 * (year - 1) + ClockMath::floorDivide(8 * year + 21, 33);
    217     dayOfYear = (daysSinceEpoch - farvardin1); // 0-based
    218     if (dayOfYear < 216) { // Compute 0-based month
    219         month = dayOfYear / 31;
    220     } else {
    221         month = (dayOfYear - 6) / 30;
    222     }
    223     dayOfMonth = dayOfYear - kPersianNumDays[month] + 1;
    224     ++dayOfYear; // Make it 1-based now
    225 
    226     internalSet(UCAL_ERA, 0);
    227     internalSet(UCAL_YEAR, year);
    228     internalSet(UCAL_EXTENDED_YEAR, year);
    229     internalSet(UCAL_MONTH, month);
    230     internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
    231     internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
    232 }
    233 
    234 UBool
    235 PersianCalendar::inDaylightTime(UErrorCode& status) const
    236 {
    237     // copied from GregorianCalendar
    238     if (U_FAILURE(status) || !getTimeZone().useDaylightTime())
    239         return FALSE;
    240 
    241     // Force an update of the state of the Calendar.
    242     ((PersianCalendar*)this)->complete(status); // cast away const
    243 
    244     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
    245 }
    246 
    247 // default century
    248 
    249 static UDate           gSystemDefaultCenturyStart       = DBL_MIN;
    250 static int32_t         gSystemDefaultCenturyStartYear   = -1;
    251 static icu::UInitOnce  gSystemDefaultCenturyInit        = U_INITONCE_INITIALIZER;
    252 
    253 UBool PersianCalendar::haveDefaultCentury() const
    254 {
    255     return TRUE;
    256 }
    257 
    258 static void U_CALLCONV initializeSystemDefaultCentury() {
    259     // initialize systemDefaultCentury and systemDefaultCenturyYear based
    260     // on the current time.  They'll be set to 80 years before
    261     // the current time.
    262     UErrorCode status = U_ZERO_ERROR;
    263     PersianCalendar calendar(Locale("@calendar=persian"),status);
    264     if (U_SUCCESS(status))
    265     {
    266         calendar.setTime(Calendar::getNow(), status);
    267         calendar.add(UCAL_YEAR, -80, status);
    268 
    269         gSystemDefaultCenturyStart = calendar.getTime(status);
    270         gSystemDefaultCenturyStartYear = calendar.get(UCAL_YEAR, status);
    271     }
    272     // We have no recourse upon failure unless we want to propagate the failure
    273     // out.
    274 }
    275 
    276 UDate PersianCalendar::defaultCenturyStart() const {
    277     // lazy-evaluate systemDefaultCenturyStart
    278     umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
    279     return gSystemDefaultCenturyStart;
    280 }
    281 
    282 int32_t PersianCalendar::defaultCenturyStartYear() const {
    283     // lazy-evaluate systemDefaultCenturyStartYear
    284     umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
    285     return gSystemDefaultCenturyStartYear;
    286 }
    287 
    288 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(PersianCalendar)
    289 
    290 U_NAMESPACE_END
    291 
    292 #endif
    293 
    294