1 /*
2  * Copyright (C) 2003-2014, International Business Machines Corporation
3  * and others. All Rights Reserved.
4  ******************************************************************************
5  *
6  * File INDIANCAL.CPP
7  *****************************************************************************
8  */
9 
10 #include "indiancal.h"
11 #include <stdlib.h>
12 #if !UCONFIG_NO_FORMATTING
13 
14 #include "mutex.h"
15 #include <float.h>
16 #include "gregoimp.h" // Math
17 #include "astro.h" // CalendarAstronomer
18 #include "uhash.h"
19 
20 // Debugging
21 #ifdef U_DEBUG_INDIANCAL
22 #include <stdio.h>
23 #include <stdarg.h>
24 
25 #endif
26 
27 U_NAMESPACE_BEGIN
28 
29 // Implementation of the IndianCalendar class
30 
31 //-------------------------------------------------------------------------
32 // Constructors...
33 //-------------------------------------------------------------------------
34 
35 
clone() const36 Calendar* IndianCalendar::clone() const {
37   return new IndianCalendar(*this);
38 }
39 
IndianCalendar(const Locale & aLocale,UErrorCode & success)40 IndianCalendar::IndianCalendar(const Locale& aLocale, UErrorCode& success)
41   :   Calendar(TimeZone::createDefault(), aLocale, success)
42 {
43   setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
44 }
45 
IndianCalendar(const IndianCalendar & other)46 IndianCalendar::IndianCalendar(const IndianCalendar& other) : Calendar(other) {
47 }
48 
~IndianCalendar()49 IndianCalendar::~IndianCalendar()
50 {
51 }
getType() const52 const char *IndianCalendar::getType() const {
53    return "indian";
54 }
55 
56 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
57     // Minimum  Greatest     Least   Maximum
58     //           Minimum   Maximum
59     {        0,        0,        0,        0}, // ERA
60     { -5000000, -5000000,  5000000,  5000000}, // YEAR
61     {        0,        0,       11,       11}, // MONTH
62     {        1,        1,       52,       53}, // WEEK_OF_YEAR
63     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
64     {        1,        1,       30,       31}, // DAY_OF_MONTH
65     {        1,        1,      365,      366}, // DAY_OF_YEAR
66     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
67     {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
68     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
69     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
70     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
71     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
72     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
73     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
74     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
75     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
76     { -5000000, -5000000,  5000000,  5000000}, // YEAR_WOY
77     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
78     { -5000000, -5000000,  5000000,  5000000}, // EXTENDED_YEAR
79     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
80     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
81     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
82 };
83 
84 static const double JULIAN_EPOCH = 1721425.5;
85 static const int32_t INDIAN_ERA_START  = 78;
86 static const int32_t INDIAN_YEAR_START = 80;
87 
handleGetLimit(UCalendarDateFields field,ELimitType limitType) const88 int32_t IndianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
89   return LIMITS[field][limitType];
90 }
91 
92 /*
93  * Determine whether the given gregorian year is a Leap year
94  */
isGregorianLeap(int32_t year)95 static UBool isGregorianLeap(int32_t year)
96 {
97     return ((year % 4) == 0) && (!(((year % 100) == 0) && ((year % 400) != 0)));
98 }
99 
100 //----------------------------------------------------------------------
101 // Calendar framework
102 //----------------------------------------------------------------------
103 
104 /*
105  * Return the length (in days) of the given month.
106  *
107  * @param eyear  The year in Saka Era
108  * @param month  The month(0-based) in Indian calendar
109  */
handleGetMonthLength(int32_t eyear,int32_t month) const110 int32_t IndianCalendar::handleGetMonthLength(int32_t eyear, int32_t month) const {
111    if (month < 0 || month > 11) {
112       eyear += ClockMath::floorDivide(month, 12, month);
113    }
114 
115    if (isGregorianLeap(eyear + INDIAN_ERA_START) && month == 0) {
116        return 31;
117    }
118 
119    if (month >= 1 && month <= 5) {
120        return 31;
121    }
122 
123    return 30;
124 }
125 
126 /*
127  * Return the number of days in the given Indian year
128  *
129  * @param eyear The year in Saka Era.
130  */
handleGetYearLength(int32_t eyear) const131 int32_t IndianCalendar::handleGetYearLength(int32_t eyear) const {
132     return isGregorianLeap(eyear + INDIAN_ERA_START) ? 366 : 365;
133 }
134 /*
135  * Returns the Julian Day corresponding to gregorian date
136  *
137  * @param year The Gregorian year
138  * @param month The month in Gregorian Year
139  * @param date The date in Gregorian day in month
140  */
gregorianToJD(int32_t year,int32_t month,int32_t date)141 static double gregorianToJD(int32_t year, int32_t month, int32_t date) {
142    double julianDay = (JULIAN_EPOCH - 1) +
143       (365 * (year - 1)) +
144       uprv_floor((year - 1) / 4) +
145       (-uprv_floor((year - 1) / 100)) +
146       uprv_floor((year - 1) / 400) +
147       uprv_floor((((367 * month) - 362) / 12) +
148             ((month <= 2) ? 0 :
149              (isGregorianLeap(year) ? -1 : -2)
150             ) +
151             date);
152 
153    return julianDay;
154 }
155 
156 /*
157  * Returns the Gregorian Date corresponding to a given Julian Day
158  * @param jd The Julian Day
159  */
jdToGregorian(double jd,int32_t gregorianDate[3])160 static int32_t* jdToGregorian(double jd, int32_t gregorianDate[3]) {
161    double wjd, depoch, quadricent, dqc, cent, dcent, quad, dquad, yindex, yearday, leapadj;
162    int32_t year, month, day;
163    wjd = uprv_floor(jd - 0.5) + 0.5;
164    depoch = wjd - JULIAN_EPOCH;
165    quadricent = uprv_floor(depoch / 146097);
166    dqc = (int32_t)uprv_floor(depoch) % 146097;
167    cent = uprv_floor(dqc / 36524);
168    dcent = (int32_t)uprv_floor(dqc) % 36524;
169    quad = uprv_floor(dcent / 1461);
170    dquad = (int32_t)uprv_floor(dcent) % 1461;
171    yindex = uprv_floor(dquad / 365);
172    year = (int32_t)((quadricent * 400) + (cent * 100) + (quad * 4) + yindex);
173    if (!((cent == 4) || (yindex == 4))) {
174       year++;
175    }
176    yearday = wjd - gregorianToJD(year, 1, 1);
177    leapadj = ((wjd < gregorianToJD(year, 3, 1)) ? 0
178          :
179          (isGregorianLeap(year) ? 1 : 2)
180          );
181    month = (int32_t)uprv_floor((((yearday + leapadj) * 12) + 373) / 367);
182    day = (int32_t)(wjd - gregorianToJD(year, month, 1)) + 1;
183 
184    gregorianDate[0] = year;
185    gregorianDate[1] = month;
186    gregorianDate[2] = day;
187 
188    return gregorianDate;
189 }
190 
191 
192 //-------------------------------------------------------------------------
193 // Functions for converting from field values to milliseconds....
194 //-------------------------------------------------------------------------
IndianToJD(int32_t year,int32_t month,int32_t date)195 static double IndianToJD(int32_t year, int32_t month, int32_t date) {
196    int32_t leapMonth, gyear, m;
197    double start, jd;
198 
199    gyear = year + INDIAN_ERA_START;
200 
201 
202    if(isGregorianLeap(gyear)) {
203       leapMonth = 31;
204       start = gregorianToJD(gyear, 3, 21);
205    }
206    else {
207       leapMonth = 30;
208       start = gregorianToJD(gyear, 3, 22);
209    }
210 
211    if (month == 1) {
212       jd = start + (date - 1);
213    } else {
214       jd = start + leapMonth;
215       m = month - 2;
216 
217       //m = Math.min(m, 5);
218       if (m > 5) {
219           m = 5;
220       }
221 
222       jd += m * 31;
223 
224       if (month >= 8) {
225          m = month - 7;
226          jd += m * 30;
227       }
228       jd += date - 1;
229    }
230 
231    return jd;
232 }
233 
234 /*
235  * Return JD of start of given month/year of Indian Calendar
236  * @param eyear The year in Indian Calendar measured from Saka Era (78 AD).
237  * @param month The month in Indian calendar
238  */
handleComputeMonthStart(int32_t eyear,int32_t month,UBool) const239 int32_t IndianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */ ) const {
240 
241    //month is 0 based; converting it to 1-based
242    int32_t imonth;
243 
244     // If the month is out of range, adjust it into range, and adjust the extended eyar accordingly
245    if (month < 0 || month > 11) {
246       eyear += (int32_t)ClockMath::floorDivide(month, 12, month);
247    }
248 
249    if(month == 12){
250        imonth = 1;
251    } else {
252        imonth = month + 1;
253    }
254 
255    double jd = IndianToJD(eyear ,imonth, 1);
256 
257    return (int32_t)jd;
258 }
259 
260 //-------------------------------------------------------------------------
261 // Functions for converting from milliseconds to field values
262 //-------------------------------------------------------------------------
263 
handleGetExtendedYear()264 int32_t IndianCalendar::handleGetExtendedYear() {
265     int32_t year;
266 
267     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
268         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
269     } else {
270         year = internalGet(UCAL_YEAR, 1); // Default to year 1
271     }
272 
273     return year;
274 }
275 
276 /*
277  * Override Calendar to compute several fields specific to the Indian
278  * calendar system.  These are:
279  *
280  * <ul><li>ERA
281  * <li>YEAR
282  * <li>MONTH
283  * <li>DAY_OF_MONTH
284  * <li>EXTENDED_YEAR</ul>
285  *
286  * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
287  * method is called. The getGregorianXxx() methods return Gregorian
288  * calendar equivalents for the given Julian day.
289  */
handleComputeFields(int32_t julianDay,UErrorCode &)290 void IndianCalendar::handleComputeFields(int32_t julianDay, UErrorCode&  /* status */) {
291     double jdAtStartOfGregYear;
292     int32_t leapMonth, IndianYear, yday, IndianMonth, IndianDayOfMonth, mday;
293     int32_t gregorianYear;      // Stores gregorian date corresponding to Julian day;
294     int32_t gd[3];
295 
296     gregorianYear = jdToGregorian(julianDay, gd)[0];          // Gregorian date for Julian day
297     IndianYear = gregorianYear - INDIAN_ERA_START;            // Year in Saka era
298     jdAtStartOfGregYear = gregorianToJD(gregorianYear, 1, 1); // JD at start of Gregorian year
299     yday = (int32_t)(julianDay - jdAtStartOfGregYear);        // Day number in Gregorian year (starting from 0)
300 
301     if (yday < INDIAN_YEAR_START) {
302         // Day is at the end of the preceding Saka year
303         IndianYear -= 1;
304         leapMonth = isGregorianLeap(gregorianYear - 1) ? 31 : 30; // Days in leapMonth this year, previous Gregorian year
305         yday += leapMonth + (31 * 5) + (30 * 3) + 10;
306     } else {
307         leapMonth = isGregorianLeap(gregorianYear) ? 31 : 30; // Days in leapMonth this year
308         yday -= INDIAN_YEAR_START;
309     }
310 
311     if (yday < leapMonth) {
312         IndianMonth = 0;
313         IndianDayOfMonth = yday + 1;
314     } else {
315         mday = yday - leapMonth;
316         if (mday < (31 * 5)) {
317             IndianMonth = (int32_t)uprv_floor(mday / 31) + 1;
318             IndianDayOfMonth = (mday % 31) + 1;
319         } else {
320             mday -= 31 * 5;
321             IndianMonth = (int32_t)uprv_floor(mday / 30) + 6;
322             IndianDayOfMonth = (mday % 30) + 1;
323         }
324    }
325 
326    internalSet(UCAL_ERA, 0);
327    internalSet(UCAL_EXTENDED_YEAR, IndianYear);
328    internalSet(UCAL_YEAR, IndianYear);
329    internalSet(UCAL_MONTH, IndianMonth);
330    internalSet(UCAL_DAY_OF_MONTH, IndianDayOfMonth);
331    internalSet(UCAL_DAY_OF_YEAR, yday + 1); // yday is 0-based
332 }
333 
334 UBool
inDaylightTime(UErrorCode & status) const335 IndianCalendar::inDaylightTime(UErrorCode& status) const
336 {
337     // copied from GregorianCalendar
338     if (U_FAILURE(status) || !getTimeZone().useDaylightTime()) {
339         return FALSE;
340     }
341 
342     // Force an update of the state of the Calendar.
343     ((IndianCalendar*)this)->complete(status); // cast away const
344 
345     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
346 }
347 
348 // default century
349 const UDate     IndianCalendar::fgSystemDefaultCentury          = DBL_MIN;
350 const int32_t   IndianCalendar::fgSystemDefaultCenturyYear      = -1;
351 
352 UDate           IndianCalendar::fgSystemDefaultCenturyStart     = DBL_MIN;
353 int32_t         IndianCalendar::fgSystemDefaultCenturyStartYear = -1;
354 
355 
haveDefaultCentury() const356 UBool IndianCalendar::haveDefaultCentury() const
357 {
358     return TRUE;
359 }
360 
defaultCenturyStart() const361 UDate IndianCalendar::defaultCenturyStart() const
362 {
363     return internalGetDefaultCenturyStart();
364 }
365 
defaultCenturyStartYear() const366 int32_t IndianCalendar::defaultCenturyStartYear() const
367 {
368     return internalGetDefaultCenturyStartYear();
369 }
370 
371 UDate
internalGetDefaultCenturyStart() const372 IndianCalendar::internalGetDefaultCenturyStart() const
373 {
374     // lazy-evaluate systemDefaultCenturyStart
375     UBool needsUpdate;
376     {
377         Mutex m;
378         needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
379     }
380 
381     if (needsUpdate) {
382         initializeSystemDefaultCentury();
383     }
384 
385     // use defaultCenturyStart unless it's the flag value;
386     // then use systemDefaultCenturyStart
387 
388     return fgSystemDefaultCenturyStart;
389 }
390 
391 int32_t
internalGetDefaultCenturyStartYear() const392 IndianCalendar::internalGetDefaultCenturyStartYear() const
393 {
394     // lazy-evaluate systemDefaultCenturyStartYear
395     UBool needsUpdate;
396     {
397         Mutex m;
398 
399         needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
400     }
401 
402     if (needsUpdate) {
403         initializeSystemDefaultCentury();
404     }
405 
406     // use defaultCenturyStart unless it's the flag value;
407     // then use systemDefaultCenturyStartYear
408 
409     return    fgSystemDefaultCenturyStartYear;
410 }
411 
412 void
initializeSystemDefaultCentury()413 IndianCalendar::initializeSystemDefaultCentury()
414 {
415     // initialize systemDefaultCentury and systemDefaultCenturyYear based
416     // on the current time.  They'll be set to 80 years before
417     // the current time.
418     // No point in locking as it should be idempotent.
419     if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury) {
420         UErrorCode status = U_ZERO_ERROR;
421 
422         IndianCalendar calendar(Locale("@calendar=Indian"),status);
423         if (U_SUCCESS(status)) {
424             calendar.setTime(Calendar::getNow(), status);
425             calendar.add(UCAL_YEAR, -80, status);
426 
427             UDate    newStart = calendar.getTime(status);
428             int32_t  newYear  = calendar.get(UCAL_YEAR, status);
429 
430             {
431                 Mutex m;
432 
433                 fgSystemDefaultCenturyStart = newStart;
434                 fgSystemDefaultCenturyStartYear = newYear;
435             }
436         }
437 
438         // We have no recourse upon failure unless we want to propagate the failure
439         // out.
440     }
441 }
442 
443 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IndianCalendar)
444 
445 U_NAMESPACE_END
446 
447 #endif
448 
449