Check in the pristine copy of ICU 4.6...

icu46/source/i18n/islamcal.cpp

+/*
+******************************************************************************
+* Copyright (C) 2003-2010, International Business Machines Corporation
+* and others. All Rights Reserved.
+******************************************************************************
+*
+* File ISLAMCAL.H
+*
+* Modification History:
+*
+*   Date        Name        Description
+*   10/14/2003  srl         ported from java IslamicCalendar
+*****************************************************************************
+*/
+
+#include "islamcal.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "umutex.h"
+#include <float.h>
+#include "gregoimp.h" // Math
+#include "astro.h" // CalendarAstronomer
+#include "uhash.h"
+#include "ucln_in.h"
+
+static const UDate HIJRA_MILLIS = -42521587200000.0;    // 7/16/622 AD 00:00
+
+// Debugging
+#ifdef U_DEBUG_ISLAMCAL
+# include <stdio.h>
+# include <stdarg.h>
+static void debug_islamcal_loc(const char *f, int32_t l)
+{
+    fprintf(stderr, "%s:%d: ", f, l);
+}
+
+static void debug_islamcal_msg(const char *pat, ...)
+{
+    va_list ap;
+    va_start(ap, pat);
+    vfprintf(stderr, pat, ap);
+    fflush(stderr);
+}
+// must use double parens, i.e.:  U_DEBUG_ISLAMCAL_MSG(("four is: %d",4));
+#define U_DEBUG_ISLAMCAL_MSG(x) {debug_islamcal_loc(__FILE__,__LINE__);debug_islamcal_msg x;}
+#else
+#define U_DEBUG_ISLAMCAL_MSG(x)
+#endif
+
+
+// --- The cache --
+// cache of months
+static UMTX astroLock = 0;  // pod bay door lock
+static U_NAMESPACE_QUALIFIER CalendarCache *gMonthCache = NULL;
+static U_NAMESPACE_QUALIFIER CalendarAstronomer *gIslamicCalendarAstro = NULL;
+
+U_CDECL_BEGIN
+static UBool calendar_islamic_cleanup(void) {
+    if (gMonthCache) {
+        delete gMonthCache;
+        gMonthCache = NULL;
+    }
+    if (gIslamicCalendarAstro) {
+        delete gIslamicCalendarAstro;
+        gIslamicCalendarAstro = NULL;
+    }
+    umtx_destroy(&astroLock);
+    return TRUE;
+}
+U_CDECL_END
+
+U_NAMESPACE_BEGIN
+
+// Implementation of the IslamicCalendar class
+
+//-------------------------------------------------------------------------
+// Constructors...
+//-------------------------------------------------------------------------
+
+const char *IslamicCalendar::getType() const { 
+    if(civil==CIVIL) {
+        return "islamic-civil";
+    } else {
+        return "islamic";
+    }
+}
+
+Calendar* IslamicCalendar::clone() const {
+    return new IslamicCalendar(*this);
+}
+
+IslamicCalendar::IslamicCalendar(const Locale& aLocale, UErrorCode& success, ECivil beCivil)
+:   Calendar(TimeZone::createDefault(), aLocale, success),
+civil(beCivil)
+{
+    setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
+}
+
+IslamicCalendar::IslamicCalendar(const IslamicCalendar& other) : Calendar(other), civil(other.civil) {
+}
+
+IslamicCalendar::~IslamicCalendar()
+{
+}
+
+/**
+* Determines whether this object uses the fixed-cycle Islamic civil calendar
+* or an approximation of the religious, astronomical calendar.
+*
+* @param beCivil   <code>true</code> to use the civil calendar,
+*                  <code>false</code> to use the astronomical calendar.
+* @draft ICU 2.4
+*/
+void IslamicCalendar::setCivil(ECivil beCivil, UErrorCode &status)
+{
+    if (civil != beCivil) {
+        // The fields of the calendar will become invalid, because the calendar
+        // rules are different
+        UDate m = getTimeInMillis(status);
+        civil = beCivil;
+        clear();
+        setTimeInMillis(m, status);
+    }
+}
+
+/**
+* Returns <code>true</code> if this object is using the fixed-cycle civil
+* calendar, or <code>false</code> if using the religious, astronomical
+* calendar.
+* @draft ICU 2.4
+*/
+UBool IslamicCalendar::isCivil() {
+    return (civil == CIVIL);
+}
+
+//-------------------------------------------------------------------------
+// Minimum / Maximum access functions
+//-------------------------------------------------------------------------
+
+// Note: Current IslamicCalendar implementation does not work
+// well with negative years.
+
+static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
+    // Minimum  Greatest    Least  Maximum
+    //           Minimum  Maximum
+    {        0,        0,        0,        0}, // ERA
+    {        1,        1,  5000000,  5000000}, // YEAR
+    {        0,        0,       11,       11}, // MONTH
+    {        1,        1,       50,       51}, // WEEK_OF_YEAR
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
+    {        1,        1,       29,       30}, // DAY_OF_MONTH
+    {        1,        1,      354,      355}, // DAY_OF_YEAR
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
+    {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
+    {        1,        1,  5000000,  5000000}, // YEAR_WOY
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
+    {        1,        1,  5000000,  5000000}, // EXTENDED_YEAR
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
+    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
+};
+
+/**
+* @draft ICU 2.4
+*/
+int32_t IslamicCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
+    return LIMITS[field][limitType];
+}
+
+//-------------------------------------------------------------------------
+// Assorted calculation utilities
+//
+
+/**
+* Determine whether a year is a leap year in the Islamic civil calendar
+*/
+UBool IslamicCalendar::civilLeapYear(int32_t year)
+{
+    return (14 + 11 * year) % 30 < 11;
+}
+
+/**
+* Return the day # on which the given year starts.  Days are counted
+* from the Hijri epoch, origin 0.
+*/
+int32_t IslamicCalendar::yearStart(int32_t year) {
+    if (civil == CIVIL) {
+        return (year-1)*354 + ClockMath::floorDivide((3+11*year),30);
+    } else {
+        return trueMonthStart(12*(year-1));
+    }
+}
+
+/**
+* Return the day # on which the given month starts.  Days are counted
+* from the Hijri epoch, origin 0.
+*
+* @param year  The hijri year
+* @param year  The hijri month, 0-based
+*/
+int32_t IslamicCalendar::monthStart(int32_t year, int32_t month) const {
+    if (civil == CIVIL) {
+        return (int32_t)uprv_ceil(29.5*month)
+            + (year-1)*354 + (int32_t)ClockMath::floorDivide((3+11*year),30);
+    } else {
+        return trueMonthStart(12*(year-1) + month);
+    }
+}
+
+/**
+* Find the day number on which a particular month of the true/lunar
+* Islamic calendar starts.
+*
+* @param month The month in question, origin 0 from the Hijri epoch
+*
+* @return The day number on which the given month starts.
+*/
+int32_t IslamicCalendar::trueMonthStart(int32_t month) const
+{
+    UErrorCode status = U_ZERO_ERROR;
+    int32_t start = CalendarCache::get(&gMonthCache, month, status);
+
+    if (start==0) {
+        // Make a guess at when the month started, using the average length
+        UDate origin = HIJRA_MILLIS 
+            + uprv_floor(month * CalendarAstronomer::SYNODIC_MONTH) * kOneDay;
+
+        // moonAge will fail due to memory allocation error
+        double age = moonAge(origin, status);
+        if (U_FAILURE(status)) {
+            goto trueMonthStartEnd;
+        }
+
+        if (age >= 0) {
+            // The month has already started
+            do {
+                origin -= kOneDay;
+                age = moonAge(origin, status);
+                if (U_FAILURE(status)) {
+                    goto trueMonthStartEnd;
+                }
+            } while (age >= 0);
+        }
+        else {
+            // Preceding month has not ended yet.
+            do {
+                origin += kOneDay;
+                age = moonAge(origin, status);
+                if (U_FAILURE(status)) {
+                    goto trueMonthStartEnd;
+                }
+            } while (age < 0);
+        }
+        start = (int32_t)ClockMath::floorDivide((origin - HIJRA_MILLIS), (double)kOneDay) + 1;
+        CalendarCache::put(&gMonthCache, month, start, status);
+    }
+trueMonthStartEnd :
+    if(U_FAILURE(status)) {
+        start = 0;
+    }
+    return start;
+}
+
+/**
+* Return the "age" of the moon at the given time; this is the difference
+* in ecliptic latitude between the moon and the sun.  This method simply
+* calls CalendarAstronomer.moonAge, converts to degrees, 
+* and adjusts the result to be in the range [-180, 180].
+*
+* @param time  The time at which the moon's age is desired,
+*              in millis since 1/1/1970.
+*/
+double IslamicCalendar::moonAge(UDate time, UErrorCode &status)
+{
+    double age = 0;
+
+    umtx_lock(&astroLock);
+    if(gIslamicCalendarAstro == NULL) {
+        gIslamicCalendarAstro = new CalendarAstronomer();
+        if (gIslamicCalendarAstro == NULL) {
+            status = U_MEMORY_ALLOCATION_ERROR;
+            return age;
+        }
+        ucln_i18n_registerCleanup(UCLN_I18N_ISLAMIC_CALENDAR, calendar_islamic_cleanup);
+    }
+    gIslamicCalendarAstro->setTime(time);
+    age = gIslamicCalendarAstro->getMoonAge();
+    umtx_unlock(&astroLock);
+
+    // Convert to degrees and normalize...
+    age = age * 180 / CalendarAstronomer::PI;
+    if (age > 180) {
+        age = age - 360;
+    }
+
+    return age;
+}
+
+//----------------------------------------------------------------------
+// Calendar framework
+//----------------------------------------------------------------------
+
+/**
+* Return the length (in days) of the given month.
+*
+* @param year  The hijri year
+* @param year  The hijri month, 0-based
+* @draft ICU 2.4
+*/
+int32_t IslamicCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
+
+    int32_t length = 0;
+
+    if (civil == CIVIL) {
+        length = 29 + (month+1) % 2;
+        if (month == DHU_AL_HIJJAH && civilLeapYear(extendedYear)) {
+            length++;
+        }
+    } else {
+        month = 12*(extendedYear-1) + month;
+        length =  trueMonthStart(month+1) - trueMonthStart(month) ;
+    }
+    return length;
+}
+
+/**
+* Return the number of days in the given Islamic year
+* @draft ICU 2.4
+*/
+int32_t IslamicCalendar::handleGetYearLength(int32_t extendedYear) const {
+    if (civil == CIVIL) {
+        return 354 + (civilLeapYear(extendedYear) ? 1 : 0);
+    } else {
+        int32_t month = 12*(extendedYear-1);
+        return (trueMonthStart(month + 12) - trueMonthStart(month));
+    }
+}
+
+//-------------------------------------------------------------------------
+// Functions for converting from field values to milliseconds....
+//-------------------------------------------------------------------------
+
+// Return JD of start of given month/year
+/**
+* @draft ICU 2.4
+*/
+int32_t IslamicCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */) const {
+    return monthStart(eyear, month) + 1948439;
+}    
+
+//-------------------------------------------------------------------------
+// Functions for converting from milliseconds to field values
+//-------------------------------------------------------------------------
+
+/**
+* @draft ICU 2.4
+*/
+int32_t IslamicCalendar::handleGetExtendedYear() {
+    int32_t year;
+    if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
+        year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
+    } else {
+        year = internalGet(UCAL_YEAR, 1); // Default to year 1
+    }
+    return year;
+}
+
+/**
+* Override Calendar to compute several fields specific to the Islamic
+* calendar system.  These are:
+*
+* <ul><li>ERA
+* <li>YEAR
+* <li>MONTH
+* <li>DAY_OF_MONTH
+* <li>DAY_OF_YEAR
+* <li>EXTENDED_YEAR</ul>
+* 
+* The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
+* method is called. The getGregorianXxx() methods return Gregorian
+* calendar equivalents for the given Julian day.
+* @draft ICU 2.4
+*/
+void IslamicCalendar::handleComputeFields(int32_t julianDay, UErrorCode &status) {
+    int32_t year, month, dayOfMonth, dayOfYear;
+    UDate startDate;
+    int32_t days = julianDay - 1948440;
+
+    if (civil == CIVIL) {
+        // Use the civil calendar approximation, which is just arithmetic
+        year  = (int)ClockMath::floorDivide( (double)(30 * days + 10646) , 10631.0 );
+        month = (int32_t)uprv_ceil((days - 29 - yearStart(year)) / 29.5 );
+        month = month<11?month:11;
+        startDate = monthStart(year, month);
+    } else {
+        // Guess at the number of elapsed full months since the epoch
+        int32_t months = (int32_t)uprv_floor((double)days / CalendarAstronomer::SYNODIC_MONTH);
+
+        startDate = uprv_floor(months * CalendarAstronomer::SYNODIC_MONTH);
+
+        double age = moonAge(internalGetTime(), status);
+        if (U_FAILURE(status)) {
+                status = U_MEMORY_ALLOCATION_ERROR;
+                return;
+        }
+        if ( days - startDate >= 25 && age > 0) {
+            // If we're near the end of the month, assume next month and search backwards
+            months++;
+        }
+
+        // Find out the last time that the new moon was actually visible at this longitude
+        // This returns midnight the night that the moon was visible at sunset.
+        while ((startDate = trueMonthStart(months)) > days) {
+            // If it was after the date in question, back up a month and try again
+            months--;
+        }
+
+        year = months / 12 + 1;
+        month = months % 12;
+    }
+
+    dayOfMonth = (days - monthStart(year, month)) + 1;
+
+    // Now figure out the day of the year.
+    dayOfYear = (days - monthStart(year, 0) + 1);
+
+    internalSet(UCAL_ERA, 0);
+    internalSet(UCAL_YEAR, year);
+    internalSet(UCAL_EXTENDED_YEAR, year);
+    internalSet(UCAL_MONTH, month);
+    internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
+    internalSet(UCAL_DAY_OF_YEAR, dayOfYear);       
+}    
+
+UBool
+IslamicCalendar::inDaylightTime(UErrorCode& status) const
+{
+    // copied from GregorianCalendar
+    if (U_FAILURE(status) || (&(getTimeZone()) == NULL && !getTimeZone().useDaylightTime())) 
+        return FALSE;
+
+    // Force an update of the state of the Calendar.
+    ((IslamicCalendar*)this)->complete(status); // cast away const
+
+    return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
+}
+
+// default century
+const UDate     IslamicCalendar::fgSystemDefaultCentury        = DBL_MIN;
+const int32_t   IslamicCalendar::fgSystemDefaultCenturyYear    = -1;
+
+UDate           IslamicCalendar::fgSystemDefaultCenturyStart       = DBL_MIN;
+int32_t         IslamicCalendar::fgSystemDefaultCenturyStartYear   = -1;
+
+
+UBool IslamicCalendar::haveDefaultCentury() const
+{
+    return TRUE;
+}
+
+UDate IslamicCalendar::defaultCenturyStart() const
+{
+    return internalGetDefaultCenturyStart();
+}
+
+int32_t IslamicCalendar::defaultCenturyStartYear() const
+{
+    return internalGetDefaultCenturyStartYear();
+}
+
+UDate
+IslamicCalendar::internalGetDefaultCenturyStart() const
+{
+    // lazy-evaluate systemDefaultCenturyStart
+    UBool needsUpdate;
+    UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
+
+    if (needsUpdate) {
+        initializeSystemDefaultCentury();
+    }
+
+    // use defaultCenturyStart unless it's the flag value;
+    // then use systemDefaultCenturyStart
+
+    return fgSystemDefaultCenturyStart;
+}
+
+int32_t
+IslamicCalendar::internalGetDefaultCenturyStartYear() const
+{
+    // lazy-evaluate systemDefaultCenturyStartYear
+    UBool needsUpdate;
+    UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
+
+    if (needsUpdate) {
+        initializeSystemDefaultCentury();
+    }
+
+    // use defaultCenturyStart unless it's the flag value;
+    // then use systemDefaultCenturyStartYear
+
+    return    fgSystemDefaultCenturyStartYear;
+}
+
+void
+IslamicCalendar::initializeSystemDefaultCentury()
+{
+    // initialize systemDefaultCentury and systemDefaultCenturyYear based
+    // on the current time.  They'll be set to 80 years before
+    // the current time.
+    UErrorCode status = U_ZERO_ERROR;
+    IslamicCalendar calendar(Locale("@calendar=islamic-civil"),status);
+    if (U_SUCCESS(status))
+    {
+        calendar.setTime(Calendar::getNow(), status);
+        calendar.add(UCAL_YEAR, -80, status);
+        UDate    newStart =  calendar.getTime(status);
+        int32_t  newYear  =  calendar.get(UCAL_YEAR, status);
+        umtx_lock(NULL);
+        if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury)
+        {
+            fgSystemDefaultCenturyStartYear = newYear;
+            fgSystemDefaultCenturyStart = newStart;
+        }
+        umtx_unlock(NULL);
+    }
+    // We have no recourse upon failure unless we want to propagate the failure
+    // out.
+}
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IslamicCalendar)
+
+U_NAMESPACE_END
+
+#endif
+