icuSources/i18n/olsontz.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: July 21 2003
   8 * Since: ICU 2.8
   9 **********************************************************************
  10 */
  11
  12 #include "olsontz.h"
  13
  14 #if !UCONFIG_NO_FORMATTING
  15
  16 #include "unicode/ures.h"
  17 #include "unicode/simpletz.h"
  18 #include "unicode/gregocal.h"
  19 #include "gregoimp.h"
  20 #include "cmemory.h"
  21 #include "uassert.h"
  22 #include <float.h> // DBL_MAX
  23
  24 #ifdef U_DEBUG_TZ
  25 # include <stdio.h>
  26 # include "uresimp.h" // for debugging
  27
  28 static void debug_tz_loc(const char *f, int32_t l)
  29 {
  30   fprintf(stderr, "%s:%d: ", f, l);
  31 }
  32
  33 static void debug_tz_msg(const char *pat, ...)
  34 {
  35   va_list ap;
  36   va_start(ap, pat);
  37   vfprintf(stderr, pat, ap);
  38   fflush(stderr);
  39 }
  40 // must use double parens, i.e.:  U_DEBUG_TZ_MSG(("four is: %d",4));
  41 #define U_DEBUG_TZ_MSG(x) {debug_tz_loc(__FILE__,__LINE__);debug_tz_msg x;}
  42 #else
  43 #define U_DEBUG_TZ_MSG(x)
  44 #endif
  45
  46 U_NAMESPACE_BEGIN
  47
  48 #define SECONDS_PER_DAY (24*60*60)
  49
  50 static const int32_t ZEROS[] = {0,0};
  51
  52 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(OlsonTimeZone)
  53
  54 /**
  55  * Default constructor.  Creates a time zone with an empty ID and
  56  * a fixed GMT offset of zero.
  57  */
  58 OlsonTimeZone::OlsonTimeZone() : finalYear(INT32_MAX), finalMillis(DBL_MAX), finalZone(0) {
  59     constructEmpty();
  60 }
  61
  62 /**
  63  * Construct a GMT+0 zone with no transitions.  This is done when a
  64  * constructor fails so the resultant object is well-behaved.
  65  */
  66 void OlsonTimeZone::constructEmpty() {
  67     transitionCount = 0;
  68     typeCount = 1;
  69     transitionTimes = typeOffsets = ZEROS;
  70     typeData = (const uint8_t*) ZEROS;
  71 }
  72
  73 /**
  74  * Construct from a resource bundle
  75  * @param top the top-level zoneinfo resource bundle.  This is used
  76  * to lookup the rule that `res' may refer to, if there is one.
  77  * @param res the resource bundle of the zone to be constructed
  78  * @param ec input-output error code
  79  */
  80 OlsonTimeZone::OlsonTimeZone(const UResourceBundle* top,
  81                              const UResourceBundle* res,
  82                              UErrorCode& ec) :
  83   finalYear(INT32_MAX), finalMillis(DBL_MAX), finalZone(0)
  84 {
  85     U_DEBUG_TZ_MSG(("OlsonTimeZone(%s)\n", ures_getKey((UResourceBundle*)res)));
  86     if ((top == NULL || res == NULL) && U_SUCCESS(ec)) {
  87         ec = U_ILLEGAL_ARGUMENT_ERROR;
  88     }
  89     if (U_SUCCESS(ec)) {
  90         // TODO -- clean up -- Doesn't work if res points to an alias
  91         //        // TODO remove nonconst casts below when ures_* API is fixed
  92         //        setID(ures_getKey((UResourceBundle*) res)); // cast away const
  93
  94         // Size 1 is an alias TO another zone (int)
  95         // HOWEVER, the caller should dereference this and never pass it in to us
  96         // Size 3 is a purely historical zone (no final rules)
  97         // Size 4 is like size 3, but with an alias list at the end
  98         // Size 5 is a hybrid zone, with historical and final elements
  99         // Size 6 is like size 5, but with an alias list at the end
 100         int32_t size = ures_getSize((UResourceBundle*) res); // cast away const
 101         if (size < 3 || size > 6) {
 102             ec = U_INVALID_FORMAT_ERROR;
 103         }
 104
 105         // Transitions list may be empty
 106         int32_t i;
 107         UResourceBundle* r = ures_getByIndex(res, 0, NULL, &ec);
 108         transitionTimes = ures_getIntVector(r, &i, &ec);
 109         ures_close(r);
 110         if ((i<0 || i>0x7FFF) && U_SUCCESS(ec)) {
 111             ec = U_INVALID_FORMAT_ERROR;
 112         }
 113         transitionCount = (int16_t) i;
 114
 115         // Type offsets list must be of even size, with size >= 2
 116         r = ures_getByIndex(res, 1, NULL, &ec);
 117         typeOffsets = ures_getIntVector(r, &i, &ec);
 118         ures_close(r);
 119         if ((i<2 || i>0x7FFE || ((i&1)!=0)) && U_SUCCESS(ec)) {
 120             ec = U_INVALID_FORMAT_ERROR;
 121         }
 122         typeCount = (int16_t) i >> 1;
 123
 124         // Type data must be of the same size as the transitions list
 125         r = ures_getByIndex(res, 2, NULL, &ec);
 126         int32_t len;
 127         typeData = ures_getBinary(r, &len, &ec);
 128         ures_close(r);
 129         if (len != transitionCount && U_SUCCESS(ec)) {
 130             ec = U_INVALID_FORMAT_ERROR;
 131         }
 132
 133 #if defined (U_DEBUG_TZ)
 134         U_DEBUG_TZ_MSG(("OlsonTimeZone(%s) - size = %d, typecount %d transitioncount %d - err %s\n", ures_getKey((UResourceBundle*)res), size, typeCount,  transitionCount, u_errorName(ec)));
 135         if(U_SUCCESS(ec)) {
 136           int32_t jj;
 137           for(jj=0;jj<transitionCount;jj++) {
 138             U_DEBUG_TZ_MSG(("   Transition %d:  time %d, typedata%d\n", jj, transitionTimes[jj], typeData[jj]));
 139           }
 140           for(jj=0;jj<transitionCount;jj++) {
 141             U_DEBUG_TZ_MSG(("   Type %d:  offset%d\n", jj, typeOffsets[jj]));
 142           }
 143         }
 144 #endif
 145
 146         // Process final rule and data, if any
 147         if (size >= 5) {
 148             int32_t ruleidLen = 0;
 149             const UChar* idUStr = ures_getStringByIndex(res, 3, &ruleidLen, &ec);
 150             UnicodeString ruleid(TRUE, idUStr, ruleidLen);
 151             r = ures_getByIndex(res, 4, NULL, &ec);
 152             const int32_t* data = ures_getIntVector(r, &len, &ec);
 153 #if defined U_DEBUG_TZ
 154             const char *rKey = ures_getKey(r);
 155             const char *zKey = ures_getKey((UResourceBundle*)res);
 156 #endif
 157             ures_close(r);
 158             if (U_SUCCESS(ec)) {
 159                 if (data != 0 && len == 2) {
 160                     int32_t rawOffset = data[0] * U_MILLIS_PER_SECOND;
 161                     // Subtract one from the actual final year; we
 162                     // actually store final year - 1, and compare
 163                     // using > rather than >=.  This allows us to use
 164                     // INT32_MAX as an exclusive upper limit for all
 165                     // years, including INT32_MAX.
 166                     U_ASSERT(data[1] > INT32_MIN);
 167                     finalYear = data[1] - 1;
 168                     // Also compute the millis for Jan 1, 0:00 GMT of the
 169                     // finalYear.  This reduces runtime computations.
 170                     finalMillis = Grego::fieldsToDay(data[1], 0, 1) * U_MILLIS_PER_DAY;
 171                     U_DEBUG_TZ_MSG(("zone%s|%s: {%d,%d}, finalYear%d, finalMillis%.1lf\n",
 172                                     zKey,rKey, data[0], data[1], finalYear, finalMillis));
 173                     r = TimeZone::loadRule(top, ruleid, NULL, ec);
 174                     if (U_SUCCESS(ec)) {
 175                         // 3, 1, -1, 7200, 0, 9, -31, -1, 7200, 0, 3600
 176                         data = ures_getIntVector(r, &len, &ec);
 177                         if (U_SUCCESS(ec) && len == 11) {
 178                             UnicodeString emptyStr;
 179                             U_DEBUG_TZ_MSG(("zone%s, rule%s: {%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d}", zKey, ures_getKey(r),
 180                                           data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7], data[8], data[9], data[10]));
 181                             finalZone = new SimpleTimeZone(rawOffset, emptyStr,
 182                                 (int8_t)data[0], (int8_t)data[1], (int8_t)data[2],
 183                                 data[3] * U_MILLIS_PER_SECOND,
 184                                 (SimpleTimeZone::TimeMode) data[4],
 185                                 (int8_t)data[5], (int8_t)data[6], (int8_t)data[7],
 186                                 data[8] * U_MILLIS_PER_SECOND,
 187                                 (SimpleTimeZone::TimeMode) data[9],
 188                                 data[10] * U_MILLIS_PER_SECOND, ec);
 189                         } else {
 190                             ec = U_INVALID_FORMAT_ERROR;
 191                         }
 192                     }
 193                     ures_close(r);
 194                 } else {
 195                     ec = U_INVALID_FORMAT_ERROR;
 196                 }
 197             }
 198         }
 199     }
 200
 201     if (U_FAILURE(ec)) {
 202         constructEmpty();
 203     }
 204 }
 205
 206 /**
 207  * Copy constructor
 208  */
 209 OlsonTimeZone::OlsonTimeZone(const OlsonTimeZone& other) :
 210     TimeZone(other), finalZone(0) {
 211     *this = other;
 212 }
 213
 214 /**
 215  * Assignment operator
 216  */
 217 OlsonTimeZone& OlsonTimeZone::operator=(const OlsonTimeZone& other) {
 218     transitionCount = other.transitionCount;
 219     typeCount = other.typeCount;
 220     transitionTimes = other.transitionTimes;
 221     typeOffsets = other.typeOffsets;
 222     typeData = other.typeData;
 223     finalYear = other.finalYear;
 224     finalMillis = other.finalMillis;
 225     delete finalZone;
 226     finalZone = (other.finalZone != 0) ?
 227         (SimpleTimeZone*) other.finalZone->clone() : 0;
 228     return *this;
 229 }
 230
 231 /**
 232  * Destructor
 233  */
 234 OlsonTimeZone::~OlsonTimeZone() {
 235     delete finalZone;
 236 }
 237
 238 /**
 239  * Returns true if the two TimeZone objects are equal.
 240  */
 241 UBool OlsonTimeZone::operator==(const TimeZone& other) const {
 242     const OlsonTimeZone* z = (const OlsonTimeZone*) &other;
 243
 244     return TimeZone::operator==(other) &&
 245         // [sic] pointer comparison: typeData points into
 246         // memory-mapped or DLL space, so if two zones have the same
 247         // pointer, they are equal.
 248         (typeData == z->typeData ||
 249          // If the pointers are not equal, the zones may still
 250          // be equal if their rules and transitions are equal
 251          (finalYear == z->finalYear &&
 252           // Don't compare finalMillis; if finalYear is ==, so is finalMillis
 253           ((finalZone == 0 && z->finalZone == 0) ||
 254            (finalZone != 0 && z->finalZone != 0 &&
 255             *finalZone == *z->finalZone)) &&
 256           transitionCount == z->transitionCount &&
 257           typeCount == z->typeCount &&
 258           uprv_memcmp(transitionTimes, z->transitionTimes,
 259                       sizeof(transitionTimes[0]) * transitionCount) == 0 &&
 260           uprv_memcmp(typeOffsets, z->typeOffsets,
 261                       (sizeof(typeOffsets[0]) * typeCount) << 1) == 0 &&
 262           uprv_memcmp(typeData, z->typeData,
 263                       (sizeof(typeData[0]) * typeCount)) == 0
 264           ));
 265 }
 266
 267 /**
 268  * TimeZone API.
 269  */
 270 TimeZone* OlsonTimeZone::clone() const {
 271     return new OlsonTimeZone(*this);
 272 }
 273
 274 /**
 275  * TimeZone API.
 276  */
 277 int32_t OlsonTimeZone::getOffset(uint8_t era, int32_t year, int32_t month,
 278                                  int32_t dom, uint8_t dow,
 279                                  int32_t millis, UErrorCode& ec) const {
 280     if (month < UCAL_JANUARY || month > UCAL_DECEMBER) {
 281         if (U_SUCCESS(ec)) {
 282             ec = U_ILLEGAL_ARGUMENT_ERROR;
 283         }
 284         return 0;
 285     } else {
 286         return getOffset(era, year, month, dom, dow, millis,
 287                          Grego::monthLength(year, month),
 288                          ec);
 289     }
 290 }
 291
 292 /**
 293  * TimeZone API.
 294  */
 295 int32_t OlsonTimeZone::getOffset(uint8_t era, int32_t year, int32_t month,
 296                                  int32_t dom, uint8_t dow,
 297                                  int32_t millis, int32_t monthLength,
 298                                  UErrorCode& ec) const {
 299     if (U_FAILURE(ec)) {
 300         return 0;
 301     }
 302
 303     if ((era != GregorianCalendar::AD && era != GregorianCalendar::BC)
 304         || month < UCAL_JANUARY
 305         || month > UCAL_DECEMBER
 306         || dom < 1
 307         || dom > monthLength
 308         || dow < UCAL_SUNDAY
 309         || dow > UCAL_SATURDAY
 310         || millis < 0
 311         || millis >= U_MILLIS_PER_DAY
 312         || monthLength < 28
 313         || monthLength > 31) {
 314         ec = U_ILLEGAL_ARGUMENT_ERROR;
 315         return 0;
 316     }
 317
 318     if (era == GregorianCalendar::BC) {
 319         year = -year;
 320     }
 321
 322     if (year > finalYear) { // [sic] >, not >=; see above
 323         U_ASSERT(finalZone != 0);
 324         return finalZone->getOffset(era, year, month, dom, dow,
 325                                     millis, monthLength, ec);
 326     }
 327
 328     // Compute local epoch seconds from input fields
 329     double time = Grego::fieldsToDay(year, month, dom) * SECONDS_PER_DAY +
 330         uprv_floor(millis / (double) U_MILLIS_PER_SECOND);
 331
 332     return zoneOffset(findTransition(time, TRUE)) * U_MILLIS_PER_SECOND;
 333 }
 334
 335 /**
 336  * TimeZone API.
 337  */
 338 void OlsonTimeZone::getOffset(UDate date, UBool local, int32_t& rawoff,
 339                               int32_t& dstoff, UErrorCode& ec) const {
 340     if (U_FAILURE(ec)) {
 341         return;
 342     }
 343
 344     // The check against finalMillis will suffice most of the time, except
 345     // for the case in which finalMillis == DBL_MAX, date == DBL_MAX,
 346     // and finalZone == 0.  For this case we add "&& finalZone != 0".
 347     if (date >= finalMillis && finalZone != 0) {
 348         int32_t year, month, dom, dow;
 349         double millis;
 350         double days = Math::floorDivide(date, (double)U_MILLIS_PER_DAY, millis);
 351
 352         Grego::dayToFields(days, year, month, dom, dow);
 353
 354         rawoff = finalZone->getRawOffset();
 355
 356         if (!local) {
 357             // Adjust from GMT to local
 358             date += rawoff;
 359             double days2 = Math::floorDivide(date, (double)U_MILLIS_PER_DAY, millis);
 360             if (days2 != days) {
 361                 Grego::dayToFields(days2, year, month, dom, dow);
 362             }
 363         }
 364
 365         dstoff = finalZone->getOffset(
 366             GregorianCalendar::AD, year, month,
 367             dom, (uint8_t) dow, (int32_t) millis, ec) - rawoff;
 368         return;
 369     }
 370
 371     double secs = uprv_floor(date / U_MILLIS_PER_SECOND);
 372     int16_t i = findTransition(secs, local);
 373     rawoff = rawOffset(i) * U_MILLIS_PER_SECOND;
 374     dstoff = dstOffset(i) * U_MILLIS_PER_SECOND;
 375 }
 376
 377 /**
 378  * TimeZone API.
 379  */
 380 void OlsonTimeZone::setRawOffset(int32_t /*offsetMillis*/) {
 381     // We don't support this operation, since OlsonTimeZones are
 382     // immutable (except for the ID, which is in the base class).
 383
 384     // Nothing to do!
 385 }
 386
 387 /**
 388  * TimeZone API.
 389  */
 390 int32_t OlsonTimeZone::getRawOffset() const {
 391     UErrorCode ec = U_ZERO_ERROR;
 392     int32_t raw, dst;
 393     getOffset((double) uprv_getUTCtime() * U_MILLIS_PER_SECOND,
 394               FALSE, raw, dst, ec);
 395     return raw;
 396 }
 397
 398 /**
 399  * Find the smallest i (in 0..transitionCount-1) such that time >=
 400  * transition(i), where transition(i) is either the GMT or the local
 401  * transition time, as specified by `local'.
 402  * @param time epoch seconds, either GMT or local wall
 403  * @param local if TRUE, `time' is in local wall units, otherwise it
 404  * is GMT
 405  * @return an index i, where 0 <= i < transitionCount, and
 406  * transition(i) <= time < transition(i+1), or i == 0 if
 407  * transitionCount == 0 or time < transition(0).
 408  */
 409 int16_t OlsonTimeZone::findTransition(double time, UBool local) const {
 410     int16_t i = 0;
 411
 412     if (transitionCount != 0) {
 413         // Linear search from the end is the fastest approach, since
 414         // most lookups will happen at/near the end.
 415         for (i = transitionCount - 1; i > 0; --i) {
 416             int32_t transition = transitionTimes[i];
 417             if (local) {
 418                 transition += zoneOffset(typeData[i]);
 419             }
 420             if (time >= transition) {
 421                 break;
 422             }
 423         }
 424
 425         U_ASSERT(i>=0 && i<transitionCount);
 426
 427         // Check invariants for GMT times; if these pass for GMT times
 428         // the local logic should be working too.
 429         U_ASSERT(local || time < transitionTimes[0] || time >= transitionTimes[i]);
 430         U_ASSERT(local || i == transitionCount-1 || time < transitionTimes[i+1]);
 431
 432         i = typeData[i];
 433     }
 434
 435     U_ASSERT(i>=0 && i<typeCount);
 436
 437     return i;
 438 }
 439
 440 /**
 441  * TimeZone API.
 442  */
 443 UBool OlsonTimeZone::useDaylightTime() const {
 444     // If DST was observed in 1942 (for example) but has never been
 445     // observed from 1943 to the present, most clients will expect
 446     // this method to return FALSE.  This method determines whether
 447     // DST is in use in the current year (at any point in the year)
 448     // and returns TRUE if so.
 449
 450     int32_t days = (int32_t)Math::floorDivide(uprv_getUTCtime(), (double)U_MILLIS_PER_DAY); // epoch days
 451
 452     int32_t year, month, dom, dow;
 453
 454     Grego::dayToFields(days, year, month, dom, dow);
 455
 456     if (year > finalYear) { // [sic] >, not >=; see above
 457         U_ASSERT(finalZone != 0 && finalZone->useDaylightTime());
 458         return TRUE;
 459     }
 460
 461     // Find start of this year, and start of next year
 462     int32_t start = (int32_t) Grego::fieldsToDay(year, 0, 1) * SECONDS_PER_DAY;
 463     int32_t limit = (int32_t) Grego::fieldsToDay(year+1, 0, 1) * SECONDS_PER_DAY;
 464
 465     // Return TRUE if DST is observed at any time during the current
 466     // year.
 467     for (int16_t i=0; i<transitionCount; ++i) {
 468         if (transitionTimes[i] >= limit) {
 469             break;
 470         }
 471         if (transitionTimes[i] >= start &&
 472             dstOffset(typeData[i]) != 0) {
 473             return TRUE;
 474         }
 475     }
 476     return FALSE;
 477 }
 478
 479 /**
 480  * TimeZone API.
 481  */
 482 UBool OlsonTimeZone::inDaylightTime(UDate date, UErrorCode& ec) const {
 483     int32_t raw, dst;
 484     getOffset(date, FALSE, raw, dst, ec);
 485     return dst != 0;
 486 }
 487
 488 U_NAMESPACE_END
 489
 490 #endif // !UCONFIG_NO_FORMATTING
 491
 492 //eof