1 /* 2 * Copyright (C) 1999-2000 Harri Porten (porten (at) kde.org) 3 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved. 4 * Copyright (C) 2009 Google Inc. All rights reserved. 5 * Copyright (C) 2007-2009 Torch Mobile, Inc. 6 * Copyright (C) 2010 &yet, LLC. (nate (at) andyet.net) 7 * 8 * The Original Code is Mozilla Communicator client code, released 9 * March 31, 1998. 10 * 11 * The Initial Developer of the Original Code is 12 * Netscape Communications Corporation. 13 * Portions created by the Initial Developer are Copyright (C) 1998 14 * the Initial Developer. All Rights Reserved. 15 * 16 * This library is free software; you can redistribute it and/or 17 * modify it under the terms of the GNU Lesser General Public 18 * License as published by the Free Software Foundation; either 19 * version 2.1 of the License, or (at your option) any later version. 20 * 21 * This library is distributed in the hope that it will be useful, 22 * but WITHOUT ANY WARRANTY; without even the implied warranty of 23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 24 * Lesser General Public License for more details. 25 * 26 * You should have received a copy of the GNU Lesser General Public 27 * License along with this library; if not, write to the Free Software 28 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 29 * 30 * Alternatively, the contents of this file may be used under the terms 31 * of either the Mozilla Public License Version 1.1, found at 32 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public 33 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html 34 * (the "GPL"), in which case the provisions of the MPL or the GPL are 35 * applicable instead of those above. If you wish to allow use of your 36 * version of this file only under the terms of one of those two 37 * licenses (the MPL or the GPL) and not to allow others to use your 38 * version of this file under the LGPL, indicate your decision by 39 * deletingthe provisions above and replace them with the notice and 40 * other provisions required by the MPL or the GPL, as the case may be. 41 * If you do not delete the provisions above, a recipient may use your 42 * version of this file under any of the LGPL, the MPL or the GPL. 43 44 * Copyright 2006-2008 the V8 project authors. All rights reserved. 45 * Redistribution and use in source and binary forms, with or without 46 * modification, are permitted provided that the following conditions are 47 * met: 48 * 49 * * Redistributions of source code must retain the above copyright 50 * notice, this list of conditions and the following disclaimer. 51 * * Redistributions in binary form must reproduce the above 52 * copyright notice, this list of conditions and the following 53 * disclaimer in the documentation and/or other materials provided 54 * with the distribution. 55 * * Neither the name of Google Inc. nor the names of its 56 * contributors may be used to endorse or promote products derived 57 * from this software without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 60 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 61 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 62 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 63 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 64 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 65 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 66 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 67 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 68 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 69 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 70 */ 71 72 #include "config.h" 73 #include "DateMath.h" 74 75 #include "Assertions.h" 76 #include "ASCIICType.h" 77 #include "CurrentTime.h" 78 #if USE(JSC) 79 #include "JSObject.h" 80 #endif 81 #include "MathExtras.h" 82 #if USE(JSC) 83 #include "ScopeChain.h" 84 #endif 85 #include "StdLibExtras.h" 86 #include "StringExtras.h" 87 88 #include <algorithm> 89 #include <limits.h> 90 #include <limits> 91 #include <stdint.h> 92 #include <time.h> 93 94 95 #if HAVE(ERRNO_H) 96 #include <errno.h> 97 #endif 98 99 #if OS(WINCE) 100 extern "C" size_t strftime(char * const s, const size_t maxsize, const char * const format, const struct tm * const t); 101 extern "C" struct tm * localtime(const time_t *timer); 102 #endif 103 104 #if HAVE(SYS_TIME_H) 105 #include <sys/time.h> 106 #endif 107 108 #if HAVE(SYS_TIMEB_H) 109 #include <sys/timeb.h> 110 #endif 111 112 #if USE(JSC) 113 #include "CallFrame.h" 114 #endif 115 116 #define NaN std::numeric_limits<double>::quiet_NaN() 117 118 using namespace WTF; 119 120 namespace WTF { 121 122 /* Constants */ 123 124 static const double minutesPerDay = 24.0 * 60.0; 125 static const double secondsPerDay = 24.0 * 60.0 * 60.0; 126 static const double secondsPerYear = 24.0 * 60.0 * 60.0 * 365.0; 127 128 static const double usecPerSec = 1000000.0; 129 130 static const double maxUnixTime = 2145859200.0; // 12/31/2037 131 // ECMAScript asks not to support for a date of which total 132 // millisecond value is larger than the following value. 133 // See 15.9.1.14 of ECMA-262 5th edition. 134 static const double maxECMAScriptTime = 8.64E15; 135 136 // Day of year for the first day of each month, where index 0 is January, and day 0 is January 1. 137 // First for non-leap years, then for leap years. 138 static const int firstDayOfMonth[2][12] = { 139 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}, 140 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335} 141 }; 142 143 static inline bool isLeapYear(int year) 144 { 145 if (year % 4 != 0) 146 return false; 147 if (year % 400 == 0) 148 return true; 149 if (year % 100 == 0) 150 return false; 151 return true; 152 } 153 154 static inline int daysInYear(int year) 155 { 156 return 365 + isLeapYear(year); 157 } 158 159 static inline double daysFrom1970ToYear(int year) 160 { 161 // The Gregorian Calendar rules for leap years: 162 // Every fourth year is a leap year. 2004, 2008, and 2012 are leap years. 163 // However, every hundredth year is not a leap year. 1900 and 2100 are not leap years. 164 // Every four hundred years, there's a leap year after all. 2000 and 2400 are leap years. 165 166 static const int leapDaysBefore1971By4Rule = 1970 / 4; 167 static const int excludedLeapDaysBefore1971By100Rule = 1970 / 100; 168 static const int leapDaysBefore1971By400Rule = 1970 / 400; 169 170 const double yearMinusOne = year - 1; 171 const double yearsToAddBy4Rule = floor(yearMinusOne / 4.0) - leapDaysBefore1971By4Rule; 172 const double yearsToExcludeBy100Rule = floor(yearMinusOne / 100.0) - excludedLeapDaysBefore1971By100Rule; 173 const double yearsToAddBy400Rule = floor(yearMinusOne / 400.0) - leapDaysBefore1971By400Rule; 174 175 return 365.0 * (year - 1970) + yearsToAddBy4Rule - yearsToExcludeBy100Rule + yearsToAddBy400Rule; 176 } 177 178 static inline double msToDays(double ms) 179 { 180 return floor(ms / msPerDay); 181 } 182 183 int msToYear(double ms) 184 { 185 int approxYear = static_cast<int>(floor(ms / (msPerDay * 365.2425)) + 1970); 186 double msFromApproxYearTo1970 = msPerDay * daysFrom1970ToYear(approxYear); 187 if (msFromApproxYearTo1970 > ms) 188 return approxYear - 1; 189 if (msFromApproxYearTo1970 + msPerDay * daysInYear(approxYear) <= ms) 190 return approxYear + 1; 191 return approxYear; 192 } 193 194 int dayInYear(double ms, int year) 195 { 196 return static_cast<int>(msToDays(ms) - daysFrom1970ToYear(year)); 197 } 198 199 static inline double msToMilliseconds(double ms) 200 { 201 double result = fmod(ms, msPerDay); 202 if (result < 0) 203 result += msPerDay; 204 return result; 205 } 206 207 // 0: Sunday, 1: Monday, etc. 208 static inline int msToWeekDay(double ms) 209 { 210 int wd = (static_cast<int>(msToDays(ms)) + 4) % 7; 211 if (wd < 0) 212 wd += 7; 213 return wd; 214 } 215 216 static inline int msToSeconds(double ms) 217 { 218 double result = fmod(floor(ms / msPerSecond), secondsPerMinute); 219 if (result < 0) 220 result += secondsPerMinute; 221 return static_cast<int>(result); 222 } 223 224 static inline int msToMinutes(double ms) 225 { 226 double result = fmod(floor(ms / msPerMinute), minutesPerHour); 227 if (result < 0) 228 result += minutesPerHour; 229 return static_cast<int>(result); 230 } 231 232 static inline int msToHours(double ms) 233 { 234 double result = fmod(floor(ms/msPerHour), hoursPerDay); 235 if (result < 0) 236 result += hoursPerDay; 237 return static_cast<int>(result); 238 } 239 240 int monthFromDayInYear(int dayInYear, bool leapYear) 241 { 242 const int d = dayInYear; 243 int step; 244 245 if (d < (step = 31)) 246 return 0; 247 step += (leapYear ? 29 : 28); 248 if (d < step) 249 return 1; 250 if (d < (step += 31)) 251 return 2; 252 if (d < (step += 30)) 253 return 3; 254 if (d < (step += 31)) 255 return 4; 256 if (d < (step += 30)) 257 return 5; 258 if (d < (step += 31)) 259 return 6; 260 if (d < (step += 31)) 261 return 7; 262 if (d < (step += 30)) 263 return 8; 264 if (d < (step += 31)) 265 return 9; 266 if (d < (step += 30)) 267 return 10; 268 return 11; 269 } 270 271 static inline bool checkMonth(int dayInYear, int& startDayOfThisMonth, int& startDayOfNextMonth, int daysInThisMonth) 272 { 273 startDayOfThisMonth = startDayOfNextMonth; 274 startDayOfNextMonth += daysInThisMonth; 275 return (dayInYear <= startDayOfNextMonth); 276 } 277 278 int dayInMonthFromDayInYear(int dayInYear, bool leapYear) 279 { 280 const int d = dayInYear; 281 int step; 282 int next = 30; 283 284 if (d <= next) 285 return d + 1; 286 const int daysInFeb = (leapYear ? 29 : 28); 287 if (checkMonth(d, step, next, daysInFeb)) 288 return d - step; 289 if (checkMonth(d, step, next, 31)) 290 return d - step; 291 if (checkMonth(d, step, next, 30)) 292 return d - step; 293 if (checkMonth(d, step, next, 31)) 294 return d - step; 295 if (checkMonth(d, step, next, 30)) 296 return d - step; 297 if (checkMonth(d, step, next, 31)) 298 return d - step; 299 if (checkMonth(d, step, next, 31)) 300 return d - step; 301 if (checkMonth(d, step, next, 30)) 302 return d - step; 303 if (checkMonth(d, step, next, 31)) 304 return d - step; 305 if (checkMonth(d, step, next, 30)) 306 return d - step; 307 step = next; 308 return d - step; 309 } 310 311 static inline int monthToDayInYear(int month, bool isLeapYear) 312 { 313 return firstDayOfMonth[isLeapYear][month]; 314 } 315 316 static inline double timeToMS(double hour, double min, double sec, double ms) 317 { 318 return (((hour * minutesPerHour + min) * secondsPerMinute + sec) * msPerSecond + ms); 319 } 320 321 double dateToDaysFrom1970(int year, int month, int day) 322 { 323 year += month / 12; 324 325 month %= 12; 326 if (month < 0) { 327 month += 12; 328 --year; 329 } 330 331 double yearday = floor(daysFrom1970ToYear(year)); 332 ASSERT((year >= 1970 && yearday >= 0) || (year < 1970 && yearday < 0)); 333 int monthday = monthToDayInYear(month, isLeapYear(year)); 334 335 return yearday + monthday + day - 1; 336 } 337 338 // There is a hard limit at 2038 that we currently do not have a workaround 339 // for (rdar://problem/5052975). 340 static inline int maximumYearForDST() 341 { 342 return 2037; 343 } 344 345 static inline int minimumYearForDST() 346 { 347 // Because of the 2038 issue (see maximumYearForDST) if the current year is 348 // greater than the max year minus 27 (2010), we want to use the max year 349 // minus 27 instead, to ensure there is a range of 28 years that all years 350 // can map to. 351 return std::min(msToYear(jsCurrentTime()), maximumYearForDST() - 27) ; 352 } 353 354 /* 355 * Find an equivalent year for the one given, where equivalence is deterined by 356 * the two years having the same leapness and the first day of the year, falling 357 * on the same day of the week. 358 * 359 * This function returns a year between this current year and 2037, however this 360 * function will potentially return incorrect results if the current year is after 361 * 2010, (rdar://problem/5052975), if the year passed in is before 1900 or after 362 * 2100, (rdar://problem/5055038). 363 */ 364 int equivalentYearForDST(int year) 365 { 366 // It is ok if the cached year is not the current year as long as the rules 367 // for DST did not change between the two years; if they did the app would need 368 // to be restarted. 369 static int minYear = minimumYearForDST(); 370 int maxYear = maximumYearForDST(); 371 372 int difference; 373 if (year > maxYear) 374 difference = minYear - year; 375 else if (year < minYear) 376 difference = maxYear - year; 377 else 378 return year; 379 380 int quotient = difference / 28; 381 int product = (quotient) * 28; 382 383 year += product; 384 ASSERT((year >= minYear && year <= maxYear) || (product - year == static_cast<int>(NaN))); 385 return year; 386 } 387 388 int32_t calculateUTCOffset() 389 { 390 #if PLATFORM(BREWMP) 391 time_t localTime = static_cast<time_t>(currentTime()); 392 #else 393 time_t localTime = time(0); 394 #endif 395 tm localt; 396 getLocalTime(&localTime, &localt); 397 398 // Get the difference between this time zone and UTC on the 1st of January of this year. 399 localt.tm_sec = 0; 400 localt.tm_min = 0; 401 localt.tm_hour = 0; 402 localt.tm_mday = 1; 403 localt.tm_mon = 0; 404 // Not setting localt.tm_year! 405 localt.tm_wday = 0; 406 localt.tm_yday = 0; 407 localt.tm_isdst = 0; 408 #if HAVE(TM_GMTOFF) 409 localt.tm_gmtoff = 0; 410 #endif 411 #if HAVE(TM_ZONE) 412 localt.tm_zone = 0; 413 #endif 414 415 #if HAVE(TIMEGM) 416 time_t utcOffset = timegm(&localt) - mktime(&localt); 417 #else 418 // Using a canned date of 01/01/2009 on platforms with weaker date-handling foo. 419 localt.tm_year = 109; 420 time_t utcOffset = 1230768000 - mktime(&localt); 421 #endif 422 423 return static_cast<int32_t>(utcOffset * 1000); 424 } 425 426 /* 427 * Get the DST offset for the time passed in. 428 */ 429 static double calculateDSTOffsetSimple(double localTimeSeconds, double utcOffset) 430 { 431 if (localTimeSeconds > maxUnixTime) 432 localTimeSeconds = maxUnixTime; 433 else if (localTimeSeconds < 0) // Go ahead a day to make localtime work (does not work with 0) 434 localTimeSeconds += secondsPerDay; 435 436 //input is UTC so we have to shift back to local time to determine DST thus the + getUTCOffset() 437 double offsetTime = (localTimeSeconds * msPerSecond) + utcOffset; 438 439 // Offset from UTC but doesn't include DST obviously 440 int offsetHour = msToHours(offsetTime); 441 int offsetMinute = msToMinutes(offsetTime); 442 443 // FIXME: time_t has a potential problem in 2038 444 time_t localTime = static_cast<time_t>(localTimeSeconds); 445 446 tm localTM; 447 getLocalTime(&localTime, &localTM); 448 449 double diff = ((localTM.tm_hour - offsetHour) * secondsPerHour) + ((localTM.tm_min - offsetMinute) * 60); 450 451 if (diff < 0) 452 diff += secondsPerDay; 453 454 return (diff * msPerSecond); 455 } 456 457 // Get the DST offset, given a time in UTC 458 double calculateDSTOffset(double ms, double utcOffset) 459 { 460 // On Mac OS X, the call to localtime (see calculateDSTOffsetSimple) will return historically accurate 461 // DST information (e.g. New Zealand did not have DST from 1946 to 1974) however the JavaScript 462 // standard explicitly dictates that historical information should not be considered when 463 // determining DST. For this reason we shift away from years that localtime can handle but would 464 // return historically accurate information. 465 int year = msToYear(ms); 466 int equivalentYear = equivalentYearForDST(year); 467 if (year != equivalentYear) { 468 bool leapYear = isLeapYear(year); 469 int dayInYearLocal = dayInYear(ms, year); 470 int dayInMonth = dayInMonthFromDayInYear(dayInYearLocal, leapYear); 471 int month = monthFromDayInYear(dayInYearLocal, leapYear); 472 double day = dateToDaysFrom1970(equivalentYear, month, dayInMonth); 473 ms = (day * msPerDay) + msToMilliseconds(ms); 474 } 475 476 return calculateDSTOffsetSimple(ms / msPerSecond, utcOffset); 477 } 478 479 void initializeDates() 480 { 481 #ifndef NDEBUG 482 static bool alreadyInitialized; 483 ASSERT(!alreadyInitialized); 484 alreadyInitialized = true; 485 #endif 486 487 equivalentYearForDST(2000); // Need to call once to initialize a static used in this function. 488 } 489 490 static inline double ymdhmsToSeconds(long year, int mon, int day, int hour, int minute, double second) 491 { 492 double days = (day - 32075) 493 + floor(1461 * (year + 4800.0 + (mon - 14) / 12) / 4) 494 + 367 * (mon - 2 - (mon - 14) / 12 * 12) / 12 495 - floor(3 * ((year + 4900.0 + (mon - 14) / 12) / 100) / 4) 496 - 2440588; 497 return ((days * hoursPerDay + hour) * minutesPerHour + minute) * secondsPerMinute + second; 498 } 499 500 // We follow the recommendation of RFC 2822 to consider all 501 // obsolete time zones not listed here equivalent to "-0000". 502 static const struct KnownZone { 503 #if !OS(WINDOWS) 504 const 505 #endif 506 char tzName[4]; 507 int tzOffset; 508 } known_zones[] = { 509 { "UT", 0 }, 510 { "GMT", 0 }, 511 { "EST", -300 }, 512 { "EDT", -240 }, 513 { "CST", -360 }, 514 { "CDT", -300 }, 515 { "MST", -420 }, 516 { "MDT", -360 }, 517 { "PST", -480 }, 518 { "PDT", -420 } 519 }; 520 521 inline static void skipSpacesAndComments(const char*& s) 522 { 523 int nesting = 0; 524 char ch; 525 while ((ch = *s)) { 526 if (!isASCIISpace(ch)) { 527 if (ch == '(') 528 nesting++; 529 else if (ch == ')' && nesting > 0) 530 nesting--; 531 else if (nesting == 0) 532 break; 533 } 534 s++; 535 } 536 } 537 538 // returns 0-11 (Jan-Dec); -1 on failure 539 static int findMonth(const char* monthStr) 540 { 541 ASSERT(monthStr); 542 char needle[4]; 543 for (int i = 0; i < 3; ++i) { 544 if (!*monthStr) 545 return -1; 546 needle[i] = static_cast<char>(toASCIILower(*monthStr++)); 547 } 548 needle[3] = '\0'; 549 const char *haystack = "janfebmaraprmayjunjulaugsepoctnovdec"; 550 const char *str = strstr(haystack, needle); 551 if (str) { 552 int position = static_cast<int>(str - haystack); 553 if (position % 3 == 0) 554 return position / 3; 555 } 556 return -1; 557 } 558 559 static bool parseLong(const char* string, char** stopPosition, int base, long* result) 560 { 561 *result = strtol(string, stopPosition, base); 562 // Avoid the use of errno as it is not available on Windows CE 563 if (string == *stopPosition || *result == LONG_MIN || *result == LONG_MAX) 564 return false; 565 return true; 566 } 567 568 double parseES5DateFromNullTerminatedCharacters(const char* dateString) 569 { 570 // This parses a date of the form defined in ECMA-262-5, section 15.9.1.15 571 // (similar to RFC 3339 / ISO 8601: YYYY-MM-DDTHH:mm:ss[.sss]Z). 572 // In most cases it is intentionally strict (e.g. correct field widths, no stray whitespace). 573 574 static const long daysPerMonth[12] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; 575 576 const char* currentPosition = dateString; 577 char* postParsePosition; 578 579 // This is a bit more lenient on the year string than ES5 specifies: 580 // instead of restricting to 4 digits (or 6 digits with mandatory +/-), 581 // it accepts any integer value. Consider this an implementation fallback. 582 long year; 583 if (!parseLong(currentPosition, &postParsePosition, 10, &year)) 584 return NaN; 585 if (*postParsePosition != '-') 586 return NaN; 587 currentPosition = postParsePosition + 1; 588 589 long month; 590 if (!isASCIIDigit(*currentPosition)) 591 return NaN; 592 if (!parseLong(currentPosition, &postParsePosition, 10, &month)) 593 return NaN; 594 if (*postParsePosition != '-' || (postParsePosition - currentPosition) != 2) 595 return NaN; 596 currentPosition = postParsePosition + 1; 597 598 long day; 599 if (!isASCIIDigit(*currentPosition)) 600 return NaN; 601 if (!parseLong(currentPosition, &postParsePosition, 10, &day)) 602 return NaN; 603 if (*postParsePosition != 'T' || (postParsePosition - currentPosition) != 2) 604 return NaN; 605 currentPosition = postParsePosition + 1; 606 607 long hours; 608 if (!isASCIIDigit(*currentPosition)) 609 return NaN; 610 if (!parseLong(currentPosition, &postParsePosition, 10, &hours)) 611 return NaN; 612 if (*postParsePosition != ':' || (postParsePosition - currentPosition) != 2) 613 return NaN; 614 currentPosition = postParsePosition + 1; 615 616 long minutes; 617 if (!isASCIIDigit(*currentPosition)) 618 return NaN; 619 if (!parseLong(currentPosition, &postParsePosition, 10, &minutes)) 620 return NaN; 621 if (*postParsePosition != ':' || (postParsePosition - currentPosition) != 2) 622 return NaN; 623 currentPosition = postParsePosition + 1; 624 625 long intSeconds; 626 if (!isASCIIDigit(*currentPosition)) 627 return NaN; 628 if (!parseLong(currentPosition, &postParsePosition, 10, &intSeconds)) 629 return NaN; 630 if ((postParsePosition - currentPosition) != 2) 631 return NaN; 632 633 double seconds = intSeconds; 634 if (*postParsePosition == '.') { 635 currentPosition = postParsePosition + 1; 636 637 // In ECMA-262-5 it's a bit unclear if '.' can be present without milliseconds, but 638 // a reasonable interpretation guided by the given examples and RFC 3339 says "no". 639 // We check the next character to avoid reading +/- timezone hours after an invalid decimal. 640 if (!isASCIIDigit(*currentPosition)) 641 return NaN; 642 643 // We are more lenient than ES5 by accepting more or less than 3 fraction digits. 644 long fracSeconds; 645 if (!parseLong(currentPosition, &postParsePosition, 10, &fracSeconds)) 646 return NaN; 647 648 long numFracDigits = postParsePosition - currentPosition; 649 seconds += fracSeconds * pow(10.0, static_cast<double>(-numFracDigits)); 650 } 651 currentPosition = postParsePosition; 652 653 // A few of these checks could be done inline above, but since many of them are interrelated 654 // we would be sacrificing readability to "optimize" the (presumably less common) failure path. 655 if (month < 1 || month > 12) 656 return NaN; 657 if (day < 1 || day > daysPerMonth[month - 1]) 658 return NaN; 659 if (month == 2 && day > 28 && !isLeapYear(year)) 660 return NaN; 661 if (hours < 0 || hours > 24) 662 return NaN; 663 if (hours == 24 && (minutes || seconds)) 664 return NaN; 665 if (minutes < 0 || minutes > 59) 666 return NaN; 667 if (seconds < 0 || seconds >= 61) 668 return NaN; 669 if (seconds > 60) { 670 // Discard leap seconds by clamping to the end of a minute. 671 seconds = 60; 672 } 673 674 long timeZoneSeconds = 0; 675 if (*currentPosition != 'Z') { 676 bool tzNegative; 677 if (*currentPosition == '-') 678 tzNegative = true; 679 else if (*currentPosition == '+') 680 tzNegative = false; 681 else 682 return NaN; 683 currentPosition += 1; 684 685 long tzHours; 686 long tzHoursAbs; 687 long tzMinutes; 688 689 if (!isASCIIDigit(*currentPosition)) 690 return NaN; 691 if (!parseLong(currentPosition, &postParsePosition, 10, &tzHours)) 692 return NaN; 693 if (*postParsePosition != ':' || (postParsePosition - currentPosition) != 2) 694 return NaN; 695 tzHoursAbs = abs(tzHours); 696 currentPosition = postParsePosition + 1; 697 698 if (!isASCIIDigit(*currentPosition)) 699 return NaN; 700 if (!parseLong(currentPosition, &postParsePosition, 10, &tzMinutes)) 701 return NaN; 702 if ((postParsePosition - currentPosition) != 2) 703 return NaN; 704 currentPosition = postParsePosition; 705 706 if (tzHoursAbs > 24) 707 return NaN; 708 if (tzMinutes < 0 || tzMinutes > 59) 709 return NaN; 710 711 timeZoneSeconds = 60 * (tzMinutes + (60 * tzHoursAbs)); 712 if (tzNegative) 713 timeZoneSeconds = -timeZoneSeconds; 714 } else { 715 currentPosition += 1; 716 } 717 if (*currentPosition) 718 return NaN; 719 720 double dateSeconds = ymdhmsToSeconds(year, month, day, hours, minutes, seconds) - timeZoneSeconds; 721 return dateSeconds * msPerSecond; 722 } 723 724 // Odd case where 'exec' is allowed to be 0, to accomodate a caller in WebCore. 725 static double parseDateFromNullTerminatedCharacters(const char* dateString, bool& haveTZ, int& offset) 726 { 727 haveTZ = false; 728 offset = 0; 729 730 // This parses a date in the form: 731 // Tuesday, 09-Nov-99 23:12:40 GMT 732 // or 733 // Sat, 01-Jan-2000 08:00:00 GMT 734 // or 735 // Sat, 01 Jan 2000 08:00:00 GMT 736 // or 737 // 01 Jan 99 22:00 +0100 (exceptions in rfc822/rfc2822) 738 // ### non RFC formats, added for Javascript: 739 // [Wednesday] January 09 1999 23:12:40 GMT 740 // [Wednesday] January 09 23:12:40 GMT 1999 741 // 742 // We ignore the weekday. 743 744 // Skip leading space 745 skipSpacesAndComments(dateString); 746 747 long month = -1; 748 const char *wordStart = dateString; 749 // Check contents of first words if not number 750 while (*dateString && !isASCIIDigit(*dateString)) { 751 if (isASCIISpace(*dateString) || *dateString == '(') { 752 if (dateString - wordStart >= 3) 753 month = findMonth(wordStart); 754 skipSpacesAndComments(dateString); 755 wordStart = dateString; 756 } else 757 dateString++; 758 } 759 760 // Missing delimiter between month and day (like "January29")? 761 if (month == -1 && wordStart != dateString) 762 month = findMonth(wordStart); 763 764 skipSpacesAndComments(dateString); 765 766 if (!*dateString) 767 return NaN; 768 769 // ' 09-Nov-99 23:12:40 GMT' 770 char* newPosStr; 771 long day; 772 if (!parseLong(dateString, &newPosStr, 10, &day)) 773 return NaN; 774 dateString = newPosStr; 775 776 if (!*dateString) 777 return NaN; 778 779 if (day < 0) 780 return NaN; 781 782 long year = 0; 783 if (day > 31) { 784 // ### where is the boundary and what happens below? 785 if (*dateString != '/') 786 return NaN; 787 // looks like a YYYY/MM/DD date 788 if (!*++dateString) 789 return NaN; 790 year = day; 791 if (!parseLong(dateString, &newPosStr, 10, &month)) 792 return NaN; 793 month -= 1; 794 dateString = newPosStr; 795 if (*dateString++ != '/' || !*dateString) 796 return NaN; 797 if (!parseLong(dateString, &newPosStr, 10, &day)) 798 return NaN; 799 dateString = newPosStr; 800 } else if (*dateString == '/' && month == -1) { 801 dateString++; 802 // This looks like a MM/DD/YYYY date, not an RFC date. 803 month = day - 1; // 0-based 804 if (!parseLong(dateString, &newPosStr, 10, &day)) 805 return NaN; 806 if (day < 1 || day > 31) 807 return NaN; 808 dateString = newPosStr; 809 if (*dateString == '/') 810 dateString++; 811 if (!*dateString) 812 return NaN; 813 } else { 814 if (*dateString == '-') 815 dateString++; 816 817 skipSpacesAndComments(dateString); 818 819 if (*dateString == ',') 820 dateString++; 821 822 if (month == -1) { // not found yet 823 month = findMonth(dateString); 824 if (month == -1) 825 return NaN; 826 827 while (*dateString && *dateString != '-' && *dateString != ',' && !isASCIISpace(*dateString)) 828 dateString++; 829 830 if (!*dateString) 831 return NaN; 832 833 // '-99 23:12:40 GMT' 834 if (*dateString != '-' && *dateString != '/' && *dateString != ',' && !isASCIISpace(*dateString)) 835 return NaN; 836 dateString++; 837 } 838 } 839 840 if (month < 0 || month > 11) 841 return NaN; 842 843 // '99 23:12:40 GMT' 844 if (year <= 0 && *dateString) { 845 if (!parseLong(dateString, &newPosStr, 10, &year)) 846 return NaN; 847 } 848 849 // Don't fail if the time is missing. 850 long hour = 0; 851 long minute = 0; 852 long second = 0; 853 if (!*newPosStr) 854 dateString = newPosStr; 855 else { 856 // ' 23:12:40 GMT' 857 if (!(isASCIISpace(*newPosStr) || *newPosStr == ',')) { 858 if (*newPosStr != ':') 859 return NaN; 860 // There was no year; the number was the hour. 861 year = -1; 862 } else { 863 // in the normal case (we parsed the year), advance to the next number 864 dateString = ++newPosStr; 865 skipSpacesAndComments(dateString); 866 } 867 868 parseLong(dateString, &newPosStr, 10, &hour); 869 // Do not check for errno here since we want to continue 870 // even if errno was set becasue we are still looking 871 // for the timezone! 872 873 // Read a number? If not, this might be a timezone name. 874 if (newPosStr != dateString) { 875 dateString = newPosStr; 876 877 if (hour < 0 || hour > 23) 878 return NaN; 879 880 if (!*dateString) 881 return NaN; 882 883 // ':12:40 GMT' 884 if (*dateString++ != ':') 885 return NaN; 886 887 if (!parseLong(dateString, &newPosStr, 10, &minute)) 888 return NaN; 889 dateString = newPosStr; 890 891 if (minute < 0 || minute > 59) 892 return NaN; 893 894 // ':40 GMT' 895 if (*dateString && *dateString != ':' && !isASCIISpace(*dateString)) 896 return NaN; 897 898 // seconds are optional in rfc822 + rfc2822 899 if (*dateString ==':') { 900 dateString++; 901 902 if (!parseLong(dateString, &newPosStr, 10, &second)) 903 return NaN; 904 dateString = newPosStr; 905 906 if (second < 0 || second > 59) 907 return NaN; 908 } 909 910 skipSpacesAndComments(dateString); 911 912 if (strncasecmp(dateString, "AM", 2) == 0) { 913 if (hour > 12) 914 return NaN; 915 if (hour == 12) 916 hour = 0; 917 dateString += 2; 918 skipSpacesAndComments(dateString); 919 } else if (strncasecmp(dateString, "PM", 2) == 0) { 920 if (hour > 12) 921 return NaN; 922 if (hour != 12) 923 hour += 12; 924 dateString += 2; 925 skipSpacesAndComments(dateString); 926 } 927 } 928 } 929 930 // The year may be after the time but before the time zone, but don't 931 // confuse a time zone specificed as an offset from UTC (e.g. +0100) with a 932 // four-digit year. 933 if (year <= 0 && *dateString != '+' && *dateString != '-') { 934 if (!parseLong(dateString, &newPosStr, 10, &year)) 935 year = 0; 936 dateString = newPosStr; 937 skipSpacesAndComments(dateString); 938 } 939 940 // Don't fail if the time zone is missing. 941 // Some websites omit the time zone (4275206). 942 if (*dateString) { 943 if (strncasecmp(dateString, "GMT", 3) == 0 || strncasecmp(dateString, "UTC", 3) == 0) { 944 dateString += 3; 945 haveTZ = true; 946 } 947 948 if (*dateString == '+' || *dateString == '-') { 949 long o; 950 if (!parseLong(dateString, &newPosStr, 10, &o)) 951 return NaN; 952 dateString = newPosStr; 953 954 if (o < -9959 || o > 9959) 955 return NaN; 956 957 int sgn = (o < 0) ? -1 : 1; 958 o = labs(o); 959 if (*dateString != ':') { 960 offset = ((o / 100) * 60 + (o % 100)) * sgn; 961 } else { // GMT+05:00 962 long o2; 963 if (!parseLong(dateString, &newPosStr, 10, &o2)) 964 return NaN; 965 dateString = newPosStr; 966 offset = (o * 60 + o2) * sgn; 967 } 968 haveTZ = true; 969 } else { 970 for (size_t i = 0; i < WTF_ARRAY_LENGTH(known_zones); ++i) { 971 if (0 == strncasecmp(dateString, known_zones[i].tzName, strlen(known_zones[i].tzName))) { 972 offset = known_zones[i].tzOffset; 973 dateString += strlen(known_zones[i].tzName); 974 haveTZ = true; 975 break; 976 } 977 } 978 } 979 } 980 981 skipSpacesAndComments(dateString); 982 983 if (*dateString && year == -1) { 984 if (!parseLong(dateString, &newPosStr, 10, &year)) 985 return NaN; 986 dateString = newPosStr; 987 } 988 989 skipSpacesAndComments(dateString); 990 991 // Trailing garbage 992 if (*dateString) 993 return NaN; 994 995 // Y2K: Handle 2 digit years. 996 if (year >= 0 && year < 100) { 997 if (year < 50) 998 year += 2000; 999 else 1000 year += 1900; 1001 } 1002 1003 return ymdhmsToSeconds(year, month + 1, day, hour, minute, second) * msPerSecond; 1004 } 1005 1006 double parseDateFromNullTerminatedCharacters(const char* dateString) 1007 { 1008 bool haveTZ; 1009 int offset; 1010 double ms = parseDateFromNullTerminatedCharacters(dateString, haveTZ, offset); 1011 if (isnan(ms)) 1012 return NaN; 1013 1014 // fall back to local timezone 1015 if (!haveTZ) { 1016 double utcOffset = calculateUTCOffset(); 1017 double dstOffset = calculateDSTOffset(ms, utcOffset); 1018 offset = static_cast<int>((utcOffset + dstOffset) / msPerMinute); 1019 } 1020 return ms - (offset * msPerMinute); 1021 } 1022 1023 double timeClip(double t) 1024 { 1025 if (!isfinite(t)) 1026 return NaN; 1027 if (fabs(t) > maxECMAScriptTime) 1028 return NaN; 1029 return trunc(t); 1030 } 1031 } // namespace WTF 1032 1033 #if USE(JSC) 1034 namespace JSC { 1035 1036 // Get the DST offset for the time passed in. 1037 // 1038 // NOTE: The implementation relies on the fact that no time zones have 1039 // more than one daylight savings offset change per month. 1040 // If this function is called with NaN it returns NaN. 1041 static double getDSTOffset(ExecState* exec, double ms, double utcOffset) 1042 { 1043 DSTOffsetCache& cache = exec->globalData().dstOffsetCache; 1044 double start = cache.start; 1045 double end = cache.end; 1046 1047 if (start <= ms) { 1048 // If the time fits in the cached interval, return the cached offset. 1049 if (ms <= end) return cache.offset; 1050 1051 // Compute a possible new interval end. 1052 double newEnd = end + cache.increment; 1053 1054 if (ms <= newEnd) { 1055 double endOffset = calculateDSTOffset(newEnd, utcOffset); 1056 if (cache.offset == endOffset) { 1057 // If the offset at the end of the new interval still matches 1058 // the offset in the cache, we grow the cached time interval 1059 // and return the offset. 1060 cache.end = newEnd; 1061 cache.increment = msPerMonth; 1062 return endOffset; 1063 } else { 1064 double offset = calculateDSTOffset(ms, utcOffset); 1065 if (offset == endOffset) { 1066 // The offset at the given time is equal to the offset at the 1067 // new end of the interval, so that means that we've just skipped 1068 // the point in time where the DST offset change occurred. Updated 1069 // the interval to reflect this and reset the increment. 1070 cache.start = ms; 1071 cache.end = newEnd; 1072 cache.increment = msPerMonth; 1073 } else { 1074 // The interval contains a DST offset change and the given time is 1075 // before it. Adjust the increment to avoid a linear search for 1076 // the offset change point and change the end of the interval. 1077 cache.increment /= 3; 1078 cache.end = ms; 1079 } 1080 // Update the offset in the cache and return it. 1081 cache.offset = offset; 1082 return offset; 1083 } 1084 } 1085 } 1086 1087 // Compute the DST offset for the time and shrink the cache interval 1088 // to only contain the time. This allows fast repeated DST offset 1089 // computations for the same time. 1090 double offset = calculateDSTOffset(ms, utcOffset); 1091 cache.offset = offset; 1092 cache.start = ms; 1093 cache.end = ms; 1094 cache.increment = msPerMonth; 1095 return offset; 1096 } 1097 1098 /* 1099 * Get the difference in milliseconds between this time zone and UTC (GMT) 1100 * NOT including DST. 1101 */ 1102 double getUTCOffset(ExecState* exec) 1103 { 1104 double utcOffset = exec->globalData().cachedUTCOffset; 1105 if (!isnan(utcOffset)) 1106 return utcOffset; 1107 exec->globalData().cachedUTCOffset = calculateUTCOffset(); 1108 return exec->globalData().cachedUTCOffset; 1109 } 1110 1111 double gregorianDateTimeToMS(ExecState* exec, const GregorianDateTime& t, double milliSeconds, bool inputIsUTC) 1112 { 1113 double day = dateToDaysFrom1970(t.year + 1900, t.month, t.monthDay); 1114 double ms = timeToMS(t.hour, t.minute, t.second, milliSeconds); 1115 double result = (day * WTF::msPerDay) + ms; 1116 1117 if (!inputIsUTC) { // convert to UTC 1118 double utcOffset = getUTCOffset(exec); 1119 result -= utcOffset; 1120 result -= getDSTOffset(exec, result, utcOffset); 1121 } 1122 1123 return result; 1124 } 1125 1126 // input is UTC 1127 void msToGregorianDateTime(ExecState* exec, double ms, bool outputIsUTC, GregorianDateTime& tm) 1128 { 1129 double dstOff = 0.0; 1130 double utcOff = 0.0; 1131 if (!outputIsUTC) { 1132 utcOff = getUTCOffset(exec); 1133 dstOff = getDSTOffset(exec, ms, utcOff); 1134 ms += dstOff + utcOff; 1135 } 1136 1137 const int year = msToYear(ms); 1138 tm.second = msToSeconds(ms); 1139 tm.minute = msToMinutes(ms); 1140 tm.hour = msToHours(ms); 1141 tm.weekDay = msToWeekDay(ms); 1142 tm.yearDay = dayInYear(ms, year); 1143 tm.monthDay = dayInMonthFromDayInYear(tm.yearDay, isLeapYear(year)); 1144 tm.month = monthFromDayInYear(tm.yearDay, isLeapYear(year)); 1145 tm.year = year - 1900; 1146 tm.isDST = dstOff != 0.0; 1147 tm.utcOffset = static_cast<long>((dstOff + utcOff) / WTF::msPerSecond); 1148 tm.timeZone = nullptr; 1149 } 1150 1151 double parseDateFromNullTerminatedCharacters(ExecState* exec, const char* dateString) 1152 { 1153 ASSERT(exec); 1154 bool haveTZ; 1155 int offset; 1156 double ms = WTF::parseDateFromNullTerminatedCharacters(dateString, haveTZ, offset); 1157 if (isnan(ms)) 1158 return NaN; 1159 1160 // fall back to local timezone 1161 if (!haveTZ) { 1162 double utcOffset = getUTCOffset(exec); 1163 double dstOffset = getDSTOffset(exec, ms, utcOffset); 1164 offset = static_cast<int>((utcOffset + dstOffset) / WTF::msPerMinute); 1165 } 1166 return ms - (offset * WTF::msPerMinute); 1167 } 1168 1169 } // namespace JSC 1170 #endif // USE(JSC) 1171
