icuSources/i18n/gregoimp.cpp

   1 /*
   2 **********************************************************************
   3 * Copyright (c) 2003-2004, International Business Machines
   4 * Corporation and others.  All Rights Reserved.
   5 **********************************************************************
   6 * Author: Alan Liu
   7 * Created: September 2 2003
   8 * Since: ICU 2.8
   9 **********************************************************************
  10 */
  11 #include "gregoimp.h"
  12
  13 #if !UCONFIG_NO_FORMATTING
  14
  15 #include "unicode/ucal.h"
  16 #include "uresimp.h"
  17 #include "cstring.h"
  18 #include "uassert.h"
  19
  20 int32_t Math::floorDivide(int32_t numerator, int32_t denominator) {
  21     return (numerator >= 0) ?
  22         numerator / denominator : ((numerator + 1) / denominator) - 1;
  23 }
  24
  25 int32_t Math::floorDivide(double numerator, int32_t denominator,
  26                           int32_t& remainder) {
  27     double quotient;
  28     quotient = uprv_floor(numerator / denominator);
  29     remainder = (int32_t) (numerator - (quotient * denominator));
  30     return (int32_t) quotient;
  31 }
  32
  33 double Math::floorDivide(double dividend, double divisor,
  34                          double& remainder) {
  35     // Only designed to work for positive divisors
  36     U_ASSERT(divisor > 0);
  37     double quotient = floorDivide(dividend, divisor);
  38     remainder = dividend - (quotient * divisor);
  39     // N.B. For certain large dividends, on certain platforms, there
  40     // is a bug such that the quotient is off by one.  If you doubt
  41     // this to be true, set a breakpoint below and run cintltst.
  42     if (remainder < 0 || remainder >= divisor) {
  43         // E.g. 6.7317038241449352e+022 / 86400000.0 is wrong on my
  44         // machine (too high by one).  4.1792057231752762e+024 /
  45         // 86400000.0 is wrong the other way (too low).
  46         double q = quotient;
  47         quotient += (remainder < 0) ? -1 : +1;
  48         if (q == quotient) {
  49             // For quotients > ~2^53, we won't be able to add or
  50             // subtract one, since the LSB of the mantissa will be >
  51             // 2^0; that is, the exponent (base 2) will be larger than
  52             // the length, in bits, of the mantissa.  In that case, we
  53             // can't give a correct answer, so we set the remainder to
  54             // zero.  This has the desired effect of making extreme
  55             // values give back an approximate answer rather than
  56             // crashing.  For example, UDate values above a ~10^25
  57             // might all have a time of midnight.
  58             remainder = 0;
  59         } else {
  60             remainder = dividend - (quotient * divisor);
  61         }
  62     }
  63     U_ASSERT(0 <= remainder && remainder < divisor);
  64     return quotient;
  65 }
  66
  67 const int32_t JULIAN_1_CE    = 1721426; // January 1, 1 CE Gregorian
  68 const int32_t JULIAN_1970_CE = 2440588; // January 1, 1970 CE Gregorian
  69
  70 const int16_t Grego::DAYS_BEFORE[24] =
  71     {0,31,59,90,120,151,181,212,243,273,304,334,
  72      0,31,60,91,121,152,182,213,244,274,305,335};
  73
  74 const int8_t Grego::MONTH_LENGTH[24] =
  75     {31,28,31,30,31,30,31,31,30,31,30,31,
  76      31,29,31,30,31,30,31,31,30,31,30,31};
  77
  78 double Grego::fieldsToDay(int32_t year, int32_t month, int32_t dom) {
  79
  80     int32_t y = year - 1;
  81
  82     double julian = 365 * y + Math::floorDivide(y, 4) + (JULIAN_1_CE - 3) + // Julian cal
  83         Math::floorDivide(y, 400) - Math::floorDivide(y, 100) + 2 + // => Gregorian cal
  84         DAYS_BEFORE[month + (isLeapYear(year) ? 12 : 0)] + dom; // => month/dom
  85
  86     return julian - JULIAN_1970_CE; // JD => epoch day
  87 }
  88
  89 void Grego::dayToFields(double day, int32_t& year, int32_t& month,
  90                         int32_t& dom, int32_t& dow, int32_t& doy) {
  91
  92     // Convert from 1970 CE epoch to 1 CE epoch (Gregorian calendar)
  93     day += JULIAN_1970_CE - JULIAN_1_CE;
  94
  95     // Convert from the day number to the multiple radix
  96     // representation.  We use 400-year, 100-year, and 4-year cycles.
  97     // For example, the 4-year cycle has 4 years + 1 leap day; giving
  98     // 1461 == 365*4 + 1 days.
  99     int32_t n400 = Math::floorDivide(day, 146097, doy); // 400-year cycle length
 100     int32_t n100 = Math::floorDivide(doy, 36524, doy); // 100-year cycle length
 101     int32_t n4   = Math::floorDivide(doy, 1461, doy); // 4-year cycle length
 102     int32_t n1   = Math::floorDivide(doy, 365, doy);
 103     year = 400*n400 + 100*n100 + 4*n4 + n1;
 104     if (n100 == 4 || n1 == 4) {
 105         doy = 365; // Dec 31 at end of 4- or 400-year cycle
 106     } else {
 107         ++year;
 108     }
 109
 110     UBool isLeap = isLeapYear(year);
 111
 112     // Gregorian day zero is a Monday.
 113     dow = (int32_t) uprv_fmod(day + 1, 7);
 114     dow += (dow < 0) ? (UCAL_SUNDAY + 7) : UCAL_SUNDAY;
 115
 116     // Common Julian/Gregorian calculation
 117     int32_t correction = 0;
 118     int32_t march1 = isLeap ? 60 : 59; // zero-based DOY for March 1
 119     if (doy >= march1) {
 120         correction = isLeap ? 1 : 2;
 121     }
 122     month = (12 * (doy + correction) + 6) / 367; // zero-based month
 123     dom = doy - DAYS_BEFORE[month + (isLeap ? 12 : 0)] + 1; // one-based DOM
 124     doy++; // one-based doy
 125 }
 126
 127 /* ---- CalendarData ------ */
 128
 129 #define U_CALENDAR_KEY "calendar"
 130 #define U_GREGORIAN_KEY "gregorian"
 131 #define U_FORMAT_KEY "format"
 132 #define U_DEFAULT_KEY "default"
 133 #define U_CALENDAR_DATA ((char*)0)
 134
 135
 136 #if defined( U_DEBUG_CALDATA)
 137 #include <stdio.h>
 138 #endif
 139
 140 // CalendarData::CalendarData(const Locale& loc, UErrorCode& status)
 141 //   : fFillin(NULL), fBundle(NULL), fFallback(NULL) {
 142 //   initData(loc.getBaseName(), (char*) "???", status);
 143 // }
 144
 145 CalendarData::CalendarData(const Locale& loc, const char *type, UErrorCode& status)
 146   : fFillin(NULL), fOtherFillin(NULL), fBundle(NULL), fFallback(NULL) {
 147   initData(loc.getBaseName(), type, status);
 148 }
 149
 150 void CalendarData::initData(const char *locale, const char *type, UErrorCode& status) {
 151   fOtherFillin = ures_open(U_CALENDAR_DATA, locale, &status);
 152   fFillin = ures_getByKey(fOtherFillin, U_CALENDAR_KEY, fFillin, &status);
 153
 154   if((type != NULL) &&
 155      (*type != '\0') &&
 156      (uprv_strcmp(type, U_GREGORIAN_KEY)))
 157   {
 158     fBundle = ures_getByKeyWithFallback(fFillin, type, NULL, &status);
 159     fFallback = ures_getByKeyWithFallback(fFillin, U_GREGORIAN_KEY, NULL, &status);
 160
 161 #if defined (U_DEBUG_CALDATA)
 162     fprintf(stderr, "%p: CalendarData(%s, %s, %s) -> main(%p, %s)=%s, fallback(%p, %s)=%s\n",
 163             this, locale, type, u_errorName(status), fBundle, type, fBundle?ures_getLocale(fBundle, &status):"",
 164             fFallback, U_GREGORIAN_KEY, fFallback?ures_getLocale(fFallback, &status):"");
 165 #endif
 166
 167   } else {
 168     fBundle = ures_getByKeyWithFallback(fFillin, U_GREGORIAN_KEY, NULL, &status);
 169 #if defined (U_DEBUG_CALDATA)
 170     fprintf(stderr, "%p: CalendarData(%s, %s, %s) -> main(%p, %s)=%s, fallback = NULL\n",
 171             this, locale, type, u_errorName(status), fBundle, U_GREGORIAN_KEY, fBundle?ures_getLocale(fBundle, &status):"" );
 172 #endif
 173   }
 174 }
 175
 176 CalendarData::~CalendarData() {
 177     ures_close(fFillin);
 178     ures_close(fBundle);
 179     ures_close(fFallback);
 180     ures_close(fOtherFillin);
 181 }
 182
 183 UResourceBundle*
 184 CalendarData::getByKey(const char *key, UErrorCode& status) {
 185     if(U_FAILURE(status)) {
 186         return NULL;
 187     }
 188
 189     if(fBundle) {
 190         fFillin = ures_getByKeyWithFallback(fBundle, key, fFillin, &status);
 191 #if defined (U_DEBUG_CALDATA)
 192         fprintf(stderr, "%p: get %s -> %s - from MAIN %s\n",this, key, u_errorName(status), ures_getLocale(fFillin, &status));
 193 #endif
 194     }
 195     if(fFallback && (status == U_MISSING_RESOURCE_ERROR)) {
 196         status = U_ZERO_ERROR; // retry with fallback (gregorian)
 197         fFillin = ures_getByKeyWithFallback(fFallback, key, fFillin, &status);
 198 #if defined (U_DEBUG_CALDATA)
 199         fprintf(stderr, "%p: get %s -> %s - from FALLBACK %s\n",this, key, u_errorName(status), ures_getLocale(fFillin, &status));
 200 #endif
 201     }
 202     return fFillin;
 203 }
 204
 205 UResourceBundle* CalendarData::getByKey2(const char *key, const char *subKey, UErrorCode& status) {
 206     if(U_FAILURE(status)) {
 207         return NULL;
 208     }
 209
 210     if(fBundle) {
 211 #if defined (U_DEBUG_CALDATA)
 212         fprintf(stderr, "%p: //\n");
 213 #endif
 214         fFillin = ures_getByKeyWithFallback(fBundle, key, fFillin, &status);
 215         fOtherFillin = ures_getByKeyWithFallback(fFillin, U_FORMAT_KEY, fOtherFillin, &status);
 216         fFillin = ures_getByKeyWithFallback(fOtherFillin, subKey, fFillin, &status);
 217 #if defined (U_DEBUG_CALDATA)
 218         fprintf(stderr, "%p: get %s/format/%s -> %s - from MAIN %s\n", this, key, subKey, u_errorName(status), ures_getLocale(fFillin, &status));
 219 #endif
 220     }
 221     if(fFallback && (status == U_MISSING_RESOURCE_ERROR)) {
 222         status = U_ZERO_ERROR; // retry with fallback (gregorian)
 223         fFillin = ures_getByKeyWithFallback(fFallback, key, fFillin, &status);
 224         fOtherFillin = ures_getByKeyWithFallback(fFillin, U_FORMAT_KEY, fOtherFillin, &status);
 225         fFillin = ures_getByKeyWithFallback(fOtherFillin, subKey, fFillin, &status);
 226 #if defined (U_DEBUG_CALDATA)
 227         fprintf(stderr, "%p: get %s/format/%s -> %s - from FALLBACK %s\n",this, key, subKey, u_errorName(status), ures_getLocale(fFillin,&status));
 228 #endif
 229     }
 230
 231 //// handling of 'default' keyword on failure: Commented out for 3.0.
 232 //   if((status == U_MISSING_RESOURCE_ERROR) &&
 233 //      uprv_strcmp(subKey,U_DEFAULT_KEY)) { // avoid recursion
 234 // #if defined (U_DEBUG_CALDATA)
 235 //     fprintf(stderr, "%p: - attempting fallback -\n", this);
 236 //     fflush(stderr);
 237 // #endif
 238 //     UErrorCode subStatus = U_ZERO_ERROR;
 239 //     int32_t len;
 240 //     char kwBuf[128] = "";
 241 //     const UChar *kw;
 242 //     /* fFillin = */ getByKey2(key, U_DEFAULT_KEY, subStatus);
 243 //     kw = ures_getString(fFillin, &len, &subStatus);
 244 //     if(len>126) { // too big
 245 //       len = 0;
 246 //     }
 247 //     if(U_SUCCESS(subStatus) && (len>0)) {
 248 //       u_UCharsToChars(kw, kwBuf, len+1);
 249 //       if(*kwBuf && uprv_strcmp(kwBuf,subKey)) {
 250 // #if defined (U_DEBUG_CALDATA)
 251 //         fprintf(stderr, "%p: trying  %s/format/default -> \"%s\"\n",this, key, kwBuf);
 252 // #endif
 253 //         // now try again with the default
 254 //         status = U_ZERO_ERROR;
 255 //         /* fFillin = */ getByKey2(key, kwBuf, status);
 256 //       }
 257 // #if defined (U_DEBUG_CALDATA)
 258 //     } else {
 259 //       fprintf(stderr, "%p: could not load  %s/format/default  - fail out (%s)\n",this, key, kwBuf, u_errorName(status));
 260 // #endif
 261 //     }
 262 //   }
 263
 264     return fFillin;
 265 }
 266
 267 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(CalendarData);
 268
 269 #endif
 270 //eof