icuSources/i18n/dangical.cpp

   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