scuffed-code/icu4c/source/i18n/islamcal.cpp
2008-08-05 22:19:05 +00:00

546 lines
16 KiB
C++

/*
******************************************************************************
* Copyright (C) 2003-2008, 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 + Math::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)Math::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 - 1) * 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)Math::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)Math::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 - 1);
double age = moonAge(internalGetTime(), status);
if (U_FAILURE(status)) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
if ( days - startDate >= 28 && 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