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      1 /*
      2  ******************************************************************************
      3  * Copyright (C) 2013, International Business Machines Corporation
      4  * and others. All Rights Reserved.
      5  ******************************************************************************
      6  *
      7  * File DANGICAL.CPP
      8  *****************************************************************************
      9  */
     10 
     11 #include "chnsecal.h"
     12 #include "dangical.h"
     13 
     14 #if !UCONFIG_NO_FORMATTING
     15 
     16 #include "umutex.h"
     17 #include "gregoimp.h" // Math
     18 #include "unicode/rbtz.h"
     19 #include "unicode/tzrule.h"
     20 #include "ucln_in.h"
     21 
     22 // --- The cache --
     23 static UMutex dangiLock = U_MUTEX_INITIALIZER;
     24 static icu::TimeZone *gDangiCalendarZoneAstroCalc = NULL;
     25 static UBool gDangiCalendarZoneAstroCalcInitialized = FALSE;
     26 
     27 /**
     28  * The start year of the Korean traditional calendar (Dan-gi) is the inaugural
     29  * year of Dan-gun (BC 2333).
     30  */
     31 static const int32_t DANGI_EPOCH_YEAR = -2332; // Gregorian year
     32 
     33 U_CDECL_BEGIN
     34 static UBool calendar_dangi_cleanup(void) {
     35     if (gDangiCalendarZoneAstroCalc) {
     36         delete gDangiCalendarZoneAstroCalc;
     37         gDangiCalendarZoneAstroCalc = NULL;
     38     }
     39     gDangiCalendarZoneAstroCalcInitialized = FALSE;
     40     return TRUE;
     41 }
     42 U_CDECL_END
     43 
     44 U_NAMESPACE_BEGIN
     45 
     46 // Implementation of the DangiCalendar class
     47 
     48 //-------------------------------------------------------------------------
     49 // Constructors...
     50 //-------------------------------------------------------------------------
     51 
     52 DangiCalendar::DangiCalendar(const Locale& aLocale, UErrorCode& success)
     53 :   ChineseCalendar(aLocale, DANGI_EPOCH_YEAR, getDangiCalZoneAstroCalc(), success)
     54 {
     55 }
     56 
     57 DangiCalendar::DangiCalendar (const DangiCalendar& other)
     58 : ChineseCalendar(other)
     59 {
     60 }
     61 
     62 DangiCalendar::~DangiCalendar()
     63 {
     64 }
     65 
     66 Calendar*
     67 DangiCalendar::clone() const
     68 {
     69     return new DangiCalendar(*this);
     70 }
     71 
     72 const char *DangiCalendar::getType() const {
     73     return "dangi";
     74 }
     75 
     76 /**
     77  * The time zone used for performing astronomical computations for
     78  * Dangi calendar. In Korea various timezones have been used historically
     79  * (cf. http://www.math.snu.ac.kr/~kye/others/lunar.html):
     80  *
     81  *            - 1908/04/01: GMT+8
     82  * 1908/04/01 - 1911/12/31: GMT+8.5
     83  * 1912/01/01 - 1954/03/20: GMT+9
     84  * 1954/03/21 - 1961/08/09: GMT+8.5
     85  * 1961/08/10 -           : GMT+9
     86  *
     87  * Note that, in 1908-1911, the government did not apply the timezone change
     88  * but used GMT+8. In addition, 1954-1961's timezone change does not affect
     89  * the lunar date calculation. Therefore, the following simpler rule works:
     90  *
     91  * -1911: GMT+8
     92  * 1912-: GMT+9
     93  *
     94  * Unfortunately, our astronomer's approximation doesn't agree with the
     95  * references (http://www.math.snu.ac.kr/~kye/others/lunar.html and
     96  * http://astro.kasi.re.kr/Life/ConvertSolarLunarForm.aspx?MenuID=115)
     97  * in 1897/7/30. So the following ad hoc fix is used here:
     98  *
     99  *     -1896: GMT+8
    100  *      1897: GMT+7
    101  * 1898-1911: GMT+8
    102  * 1912-    : GMT+9
    103  */
    104 const TimeZone* DangiCalendar::getDangiCalZoneAstroCalc(void) const {
    105     UBool initialized;
    106     UMTX_CHECK(&dangiLock, gDangiCalendarZoneAstroCalcInitialized, initialized);
    107     if (!initialized) {
    108         umtx_lock(&dangiLock);
    109         {
    110             if (!gDangiCalendarZoneAstroCalcInitialized) {
    111                 const UDate millis1897[] = { (UDate)((1897 - 1970) * 365 * kOneDay) }; // some days of error is not a problem here
    112                 const UDate millis1898[] = { (UDate)((1898 - 1970) * 365 * kOneDay) }; // some days of error is not a problem here
    113                 const UDate millis1912[] = { (UDate)((1912 - 1970) * 365 * kOneDay) }; // this doesn't create an issue for 1911/12/20
    114                 InitialTimeZoneRule* initialTimeZone = new InitialTimeZoneRule(UNICODE_STRING_SIMPLE("GMT+8"), 8*kOneHour, 0);
    115                 TimeZoneRule* rule1897 = new TimeArrayTimeZoneRule(UNICODE_STRING_SIMPLE("Korean 1897"), 7*kOneHour, 0, millis1897, 1, DateTimeRule::STANDARD_TIME);
    116                 TimeZoneRule* rule1898to1911 = new TimeArrayTimeZoneRule(UNICODE_STRING_SIMPLE("Korean 1898-1911"), 8*kOneHour, 0, millis1898, 1, DateTimeRule::STANDARD_TIME);
    117                 TimeZoneRule* ruleFrom1912 = new TimeArrayTimeZoneRule(UNICODE_STRING_SIMPLE("Korean 1912-"), 9*kOneHour, 0, millis1912, 1, DateTimeRule::STANDARD_TIME);
    118                 UErrorCode status = U_ZERO_ERROR;
    119                 RuleBasedTimeZone* dangiCalZoneAstroCalc = new RuleBasedTimeZone(UNICODE_STRING_SIMPLE("KOREA_ZONE"), initialTimeZone); // adopts initialTimeZone
    120                 dangiCalZoneAstroCalc->addTransitionRule(rule1897, status); // adopts rule1897
    121                 dangiCalZoneAstroCalc->addTransitionRule(rule1898to1911, status);
    122                 dangiCalZoneAstroCalc->addTransitionRule(ruleFrom1912, status);
    123                 dangiCalZoneAstroCalc->complete(status);
    124                 if (U_SUCCESS(status)) {
    125                     gDangiCalendarZoneAstroCalc = dangiCalZoneAstroCalc;
    126                 } else {
    127                     delete dangiCalZoneAstroCalc;
    128                     gDangiCalendarZoneAstroCalc = NULL;
    129                 }
    130                 gDangiCalendarZoneAstroCalcInitialized = TRUE;
    131                 ucln_i18n_registerCleanup(UCLN_I18N_DANGI_CALENDAR, calendar_dangi_cleanup);
    132             }
    133         }
    134         umtx_unlock(&dangiLock);
    135     }
    136     return gDangiCalendarZoneAstroCalc;
    137 }
    138 
    139 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(DangiCalendar)
    140 
    141 U_NAMESPACE_END
    142 
    143 #endif
    144 
    145