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 #include "MathExtras.h" 79 #include "StdLibExtras.h" 80 #include "StringExtras.h" 81 82 #include <algorithm> 83 #include <limits.h> 84 #include <limits> 85 #include <math.h> 86 #include <stdlib.h> 87 #include <time.h> 88 #include "wtf/text/StringBuilder.h" 89 90 #if OS(WIN) 91 #include <windows.h> 92 #endif 93 94 #if HAVE(SYS_TIME_H) 95 #include <sys/time.h> 96 #endif 97 98 using namespace WTF; 99 100 namespace WTF { 101 102 /* Constants */ 103 104 static const double hoursPerDay = 24.0; 105 static const double secondsPerDay = 24.0 * 60.0 * 60.0; 106 static const double secondsPerHour = 60.0 * 60.0; 107 108 static const double maxUnixTime = 2145859200.0; // 12/31/2037 109 110 // Day of year for the first day of each month, where index 0 is January, and day 0 is January 1. 111 // First for non-leap years, then for leap years. 112 static const int firstDayOfMonth[2][12] = { 113 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}, 114 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335} 115 }; 116 117 static inline void getLocalTime(const time_t* localTime, struct tm* localTM) 118 { 119 #if COMPILER(MSVC) 120 localtime_s(localTM, localTime); 121 #else 122 localtime_r(localTime, localTM); 123 #endif 124 } 125 126 bool isLeapYear(int year) 127 { 128 if (year % 4 != 0) 129 return false; 130 if (year % 400 == 0) 131 return true; 132 if (year % 100 == 0) 133 return false; 134 return true; 135 } 136 137 static inline int daysInYear(int year) 138 { 139 return 365 + isLeapYear(year); 140 } 141 142 static inline double daysFrom1970ToYear(int year) 143 { 144 // The Gregorian Calendar rules for leap years: 145 // Every fourth year is a leap year. 2004, 2008, and 2012 are leap years. 146 // However, every hundredth year is not a leap year. 1900 and 2100 are not leap years. 147 // Every four hundred years, there's a leap year after all. 2000 and 2400 are leap years. 148 149 static const int leapDaysBefore1971By4Rule = 1970 / 4; 150 static const int excludedLeapDaysBefore1971By100Rule = 1970 / 100; 151 static const int leapDaysBefore1971By400Rule = 1970 / 400; 152 153 const double yearMinusOne = year - 1; 154 const double yearsToAddBy4Rule = floor(yearMinusOne / 4.0) - leapDaysBefore1971By4Rule; 155 const double yearsToExcludeBy100Rule = floor(yearMinusOne / 100.0) - excludedLeapDaysBefore1971By100Rule; 156 const double yearsToAddBy400Rule = floor(yearMinusOne / 400.0) - leapDaysBefore1971By400Rule; 157 158 return 365.0 * (year - 1970) + yearsToAddBy4Rule - yearsToExcludeBy100Rule + yearsToAddBy400Rule; 159 } 160 161 static double msToDays(double ms) 162 { 163 return floor(ms / msPerDay); 164 } 165 166 static String twoDigitStringFromNumber(int number) 167 { 168 ASSERT(number >= 0 && number < 100); 169 if (number > 9) 170 return String::number(number); 171 return "0" + String::number(number); 172 } 173 174 int msToYear(double ms) 175 { 176 int approxYear = static_cast<int>(floor(ms / (msPerDay * 365.2425)) + 1970); 177 double msFromApproxYearTo1970 = msPerDay * daysFrom1970ToYear(approxYear); 178 if (msFromApproxYearTo1970 > ms) 179 return approxYear - 1; 180 if (msFromApproxYearTo1970 + msPerDay * daysInYear(approxYear) <= ms) 181 return approxYear + 1; 182 return approxYear; 183 } 184 185 int dayInYear(double ms, int year) 186 { 187 return static_cast<int>(msToDays(ms) - daysFrom1970ToYear(year)); 188 } 189 190 static inline double msToMilliseconds(double ms) 191 { 192 double result = fmod(ms, msPerDay); 193 if (result < 0) 194 result += msPerDay; 195 return result; 196 } 197 198 static int msToMinutes(double ms) 199 { 200 double result = fmod(floor(ms / msPerMinute), minutesPerHour); 201 if (result < 0) 202 result += minutesPerHour; 203 return static_cast<int>(result); 204 } 205 206 static int msToHours(double ms) 207 { 208 double result = fmod(floor(ms/msPerHour), hoursPerDay); 209 if (result < 0) 210 result += hoursPerDay; 211 return static_cast<int>(result); 212 } 213 214 int monthFromDayInYear(int dayInYear, bool leapYear) 215 { 216 const int d = dayInYear; 217 int step; 218 219 if (d < (step = 31)) 220 return 0; 221 step += (leapYear ? 29 : 28); 222 if (d < step) 223 return 1; 224 if (d < (step += 31)) 225 return 2; 226 if (d < (step += 30)) 227 return 3; 228 if (d < (step += 31)) 229 return 4; 230 if (d < (step += 30)) 231 return 5; 232 if (d < (step += 31)) 233 return 6; 234 if (d < (step += 31)) 235 return 7; 236 if (d < (step += 30)) 237 return 8; 238 if (d < (step += 31)) 239 return 9; 240 if (d < (step += 30)) 241 return 10; 242 return 11; 243 } 244 245 static inline bool checkMonth(int dayInYear, int& startDayOfThisMonth, int& startDayOfNextMonth, int daysInThisMonth) 246 { 247 startDayOfThisMonth = startDayOfNextMonth; 248 startDayOfNextMonth += daysInThisMonth; 249 return (dayInYear <= startDayOfNextMonth); 250 } 251 252 int dayInMonthFromDayInYear(int dayInYear, bool leapYear) 253 { 254 const int d = dayInYear; 255 int step; 256 int next = 30; 257 258 if (d <= next) 259 return d + 1; 260 const int daysInFeb = (leapYear ? 29 : 28); 261 if (checkMonth(d, step, next, daysInFeb)) 262 return d - step; 263 if (checkMonth(d, step, next, 31)) 264 return d - step; 265 if (checkMonth(d, step, next, 30)) 266 return d - step; 267 if (checkMonth(d, step, next, 31)) 268 return d - step; 269 if (checkMonth(d, step, next, 30)) 270 return d - step; 271 if (checkMonth(d, step, next, 31)) 272 return d - step; 273 if (checkMonth(d, step, next, 31)) 274 return d - step; 275 if (checkMonth(d, step, next, 30)) 276 return d - step; 277 if (checkMonth(d, step, next, 31)) 278 return d - step; 279 if (checkMonth(d, step, next, 30)) 280 return d - step; 281 step = next; 282 return d - step; 283 } 284 285 int dayInYear(int year, int month, int day) 286 { 287 return firstDayOfMonth[isLeapYear(year)][month] + day - 1; 288 } 289 290 double dateToDaysFrom1970(int year, int month, int day) 291 { 292 year += month / 12; 293 294 month %= 12; 295 if (month < 0) { 296 month += 12; 297 --year; 298 } 299 300 double yearday = floor(daysFrom1970ToYear(year)); 301 ASSERT((year >= 1970 && yearday >= 0) || (year < 1970 && yearday < 0)); 302 return yearday + dayInYear(year, month, day); 303 } 304 305 // There is a hard limit at 2038 that we currently do not have a workaround 306 // for (rdar://problem/5052975). 307 static inline int maximumYearForDST() 308 { 309 return 2037; 310 } 311 312 static inline double jsCurrentTime() 313 { 314 // JavaScript doesn't recognize fractions of a millisecond. 315 return floor(WTF::currentTimeMS()); 316 } 317 318 static inline int minimumYearForDST() 319 { 320 // Because of the 2038 issue (see maximumYearForDST) if the current year is 321 // greater than the max year minus 27 (2010), we want to use the max year 322 // minus 27 instead, to ensure there is a range of 28 years that all years 323 // can map to. 324 return std::min(msToYear(jsCurrentTime()), maximumYearForDST() - 27) ; 325 } 326 327 /* 328 * Find an equivalent year for the one given, where equivalence is deterined by 329 * the two years having the same leapness and the first day of the year, falling 330 * on the same day of the week. 331 * 332 * This function returns a year between this current year and 2037, however this 333 * function will potentially return incorrect results if the current year is after 334 * 2010, (rdar://problem/5052975), if the year passed in is before 1900 or after 335 * 2100, (rdar://problem/5055038). 336 */ 337 static int equivalentYearForDST(int year) 338 { 339 // It is ok if the cached year is not the current year as long as the rules 340 // for DST did not change between the two years; if they did the app would need 341 // to be restarted. 342 static int minYear = minimumYearForDST(); 343 int maxYear = maximumYearForDST(); 344 345 int difference; 346 if (year > maxYear) 347 difference = minYear - year; 348 else if (year < minYear) 349 difference = maxYear - year; 350 else 351 return year; 352 353 int quotient = difference / 28; 354 int product = (quotient) * 28; 355 356 year += product; 357 ASSERT((year >= minYear && year <= maxYear) || (product - year == static_cast<int>(std::numeric_limits<double>::quiet_NaN()))); 358 return year; 359 } 360 361 int32_t calculateUTCOffset() 362 { 363 #if OS(WIN) 364 TIME_ZONE_INFORMATION timeZoneInformation; 365 GetTimeZoneInformation(&timeZoneInformation); 366 int32_t bias = timeZoneInformation.Bias + timeZoneInformation.StandardBias; 367 return -bias * 60 * 1000; 368 #else 369 time_t localTime = time(0); 370 tm localt; 371 getLocalTime(&localTime, &localt); 372 373 // Get the difference between this time zone and UTC on the 1st of January of this year. 374 localt.tm_sec = 0; 375 localt.tm_min = 0; 376 localt.tm_hour = 0; 377 localt.tm_mday = 1; 378 localt.tm_mon = 0; 379 // Not setting localt.tm_year! 380 localt.tm_wday = 0; 381 localt.tm_yday = 0; 382 localt.tm_isdst = 0; 383 #if HAVE(TM_GMTOFF) 384 localt.tm_gmtoff = 0; 385 #endif 386 #if HAVE(TM_ZONE) 387 localt.tm_zone = 0; 388 #endif 389 390 #if HAVE(TIMEGM) 391 time_t utcOffset = timegm(&localt) - mktime(&localt); 392 #else 393 // Using a canned date of 01/01/2009 on platforms with weaker date-handling foo. 394 localt.tm_year = 109; 395 time_t utcOffset = 1230768000 - mktime(&localt); 396 #endif 397 398 return static_cast<int32_t>(utcOffset * 1000); 399 #endif 400 } 401 402 /* 403 * Get the DST offset for the time passed in. 404 */ 405 static double calculateDSTOffsetSimple(double localTimeSeconds, double utcOffset) 406 { 407 if (localTimeSeconds > maxUnixTime) 408 localTimeSeconds = maxUnixTime; 409 else if (localTimeSeconds < 0) // Go ahead a day to make localtime work (does not work with 0) 410 localTimeSeconds += secondsPerDay; 411 412 //input is UTC so we have to shift back to local time to determine DST thus the + getUTCOffset() 413 double offsetTime = (localTimeSeconds * msPerSecond) + utcOffset; 414 415 // Offset from UTC but doesn't include DST obviously 416 int offsetHour = msToHours(offsetTime); 417 int offsetMinute = msToMinutes(offsetTime); 418 419 // FIXME: time_t has a potential problem in 2038 420 time_t localTime = static_cast<time_t>(localTimeSeconds); 421 422 tm localTM; 423 getLocalTime(&localTime, &localTM); 424 425 double diff = ((localTM.tm_hour - offsetHour) * secondsPerHour) + ((localTM.tm_min - offsetMinute) * 60); 426 427 if (diff < 0) 428 diff += secondsPerDay; 429 430 return (diff * msPerSecond); 431 } 432 433 // Get the DST offset, given a time in UTC 434 double calculateDSTOffset(double ms, double utcOffset) 435 { 436 // On Mac OS X, the call to localtime (see calculateDSTOffsetSimple) will return historically accurate 437 // DST information (e.g. New Zealand did not have DST from 1946 to 1974) however the JavaScript 438 // standard explicitly dictates that historical information should not be considered when 439 // determining DST. For this reason we shift away from years that localtime can handle but would 440 // return historically accurate information. 441 int year = msToYear(ms); 442 int equivalentYear = equivalentYearForDST(year); 443 if (year != equivalentYear) { 444 bool leapYear = isLeapYear(year); 445 int dayInYearLocal = dayInYear(ms, year); 446 int dayInMonth = dayInMonthFromDayInYear(dayInYearLocal, leapYear); 447 int month = monthFromDayInYear(dayInYearLocal, leapYear); 448 double day = dateToDaysFrom1970(equivalentYear, month, dayInMonth); 449 ms = (day * msPerDay) + msToMilliseconds(ms); 450 } 451 452 return calculateDSTOffsetSimple(ms / msPerSecond, utcOffset); 453 } 454 455 void initializeDates() 456 { 457 #if !ASSERT_DISABLED 458 static bool alreadyInitialized; 459 ASSERT(!alreadyInitialized); 460 alreadyInitialized = true; 461 #endif 462 463 equivalentYearForDST(2000); // Need to call once to initialize a static used in this function. 464 } 465 466 static inline double ymdhmsToSeconds(int year, long mon, long day, long hour, long minute, double second) 467 { 468 double days = (day - 32075) 469 + floor(1461 * (year + 4800.0 + (mon - 14) / 12) / 4) 470 + 367 * (mon - 2 - (mon - 14) / 12 * 12) / 12 471 - floor(3 * ((year + 4900.0 + (mon - 14) / 12) / 100) / 4) 472 - 2440588; 473 return ((days * hoursPerDay + hour) * minutesPerHour + minute) * secondsPerMinute + second; 474 } 475 476 // We follow the recommendation of RFC 2822 to consider all 477 // obsolete time zones not listed here equivalent to "-0000". 478 static const struct KnownZone { 479 #if !OS(WIN) 480 const 481 #endif 482 char tzName[4]; 483 int tzOffset; 484 } known_zones[] = { 485 { "UT", 0 }, 486 { "GMT", 0 }, 487 { "EST", -300 }, 488 { "EDT", -240 }, 489 { "CST", -360 }, 490 { "CDT", -300 }, 491 { "MST", -420 }, 492 { "MDT", -360 }, 493 { "PST", -480 }, 494 { "PDT", -420 } 495 }; 496 497 inline static void skipSpacesAndComments(const char*& s) 498 { 499 int nesting = 0; 500 char ch; 501 while ((ch = *s)) { 502 if (!isASCIISpace(ch)) { 503 if (ch == '(') 504 nesting++; 505 else if (ch == ')' && nesting > 0) 506 nesting--; 507 else if (nesting == 0) 508 break; 509 } 510 s++; 511 } 512 } 513 514 // returns 0-11 (Jan-Dec); -1 on failure 515 static int findMonth(const char* monthStr) 516 { 517 ASSERT(monthStr); 518 char needle[4]; 519 for (int i = 0; i < 3; ++i) { 520 if (!*monthStr) 521 return -1; 522 needle[i] = static_cast<char>(toASCIILower(*monthStr++)); 523 } 524 needle[3] = '\0'; 525 const char *haystack = "janfebmaraprmayjunjulaugsepoctnovdec"; 526 const char *str = strstr(haystack, needle); 527 if (str) { 528 int position = static_cast<int>(str - haystack); 529 if (position % 3 == 0) 530 return position / 3; 531 } 532 return -1; 533 } 534 535 static bool parseInt(const char* string, char** stopPosition, int base, int* result) 536 { 537 long longResult = strtol(string, stopPosition, base); 538 // Avoid the use of errno as it is not available on Windows CE 539 if (string == *stopPosition || longResult <= std::numeric_limits<int>::min() || longResult >= std::numeric_limits<int>::max()) 540 return false; 541 *result = static_cast<int>(longResult); 542 return true; 543 } 544 545 static bool parseLong(const char* string, char** stopPosition, int base, long* result) 546 { 547 *result = strtol(string, stopPosition, base); 548 // Avoid the use of errno as it is not available on Windows CE 549 if (string == *stopPosition || *result == std::numeric_limits<long>::min() || *result == std::numeric_limits<long>::max()) 550 return false; 551 return true; 552 } 553 554 // Odd case where 'exec' is allowed to be 0, to accomodate a caller in WebCore. 555 static double parseDateFromNullTerminatedCharacters(const char* dateString, bool& haveTZ, int& offset) 556 { 557 haveTZ = false; 558 offset = 0; 559 560 // This parses a date in the form: 561 // Tuesday, 09-Nov-99 23:12:40 GMT 562 // or 563 // Sat, 01-Jan-2000 08:00:00 GMT 564 // or 565 // Sat, 01 Jan 2000 08:00:00 GMT 566 // or 567 // 01 Jan 99 22:00 +0100 (exceptions in rfc822/rfc2822) 568 // ### non RFC formats, added for Javascript: 569 // [Wednesday] January 09 1999 23:12:40 GMT 570 // [Wednesday] January 09 23:12:40 GMT 1999 571 // 572 // We ignore the weekday. 573 574 // Skip leading space 575 skipSpacesAndComments(dateString); 576 577 long month = -1; 578 const char *wordStart = dateString; 579 // Check contents of first words if not number 580 while (*dateString && !isASCIIDigit(*dateString)) { 581 if (isASCIISpace(*dateString) || *dateString == '(') { 582 if (dateString - wordStart >= 3) 583 month = findMonth(wordStart); 584 skipSpacesAndComments(dateString); 585 wordStart = dateString; 586 } else 587 dateString++; 588 } 589 590 // Missing delimiter between month and day (like "January29")? 591 if (month == -1 && wordStart != dateString) 592 month = findMonth(wordStart); 593 594 skipSpacesAndComments(dateString); 595 596 if (!*dateString) 597 return std::numeric_limits<double>::quiet_NaN(); 598 599 // ' 09-Nov-99 23:12:40 GMT' 600 char* newPosStr; 601 long day; 602 if (!parseLong(dateString, &newPosStr, 10, &day)) 603 return std::numeric_limits<double>::quiet_NaN(); 604 dateString = newPosStr; 605 606 if (!*dateString) 607 return std::numeric_limits<double>::quiet_NaN(); 608 609 if (day < 0) 610 return std::numeric_limits<double>::quiet_NaN(); 611 612 int year = 0; 613 if (day > 31) { 614 // ### where is the boundary and what happens below? 615 if (*dateString != '/') 616 return std::numeric_limits<double>::quiet_NaN(); 617 // looks like a YYYY/MM/DD date 618 if (!*++dateString) 619 return std::numeric_limits<double>::quiet_NaN(); 620 if (day <= std::numeric_limits<int>::min() || day >= std::numeric_limits<int>::max()) 621 return std::numeric_limits<double>::quiet_NaN(); 622 year = static_cast<int>(day); 623 if (!parseLong(dateString, &newPosStr, 10, &month)) 624 return std::numeric_limits<double>::quiet_NaN(); 625 month -= 1; 626 dateString = newPosStr; 627 if (*dateString++ != '/' || !*dateString) 628 return std::numeric_limits<double>::quiet_NaN(); 629 if (!parseLong(dateString, &newPosStr, 10, &day)) 630 return std::numeric_limits<double>::quiet_NaN(); 631 dateString = newPosStr; 632 } else if (*dateString == '/' && month == -1) { 633 dateString++; 634 // This looks like a MM/DD/YYYY date, not an RFC date. 635 month = day - 1; // 0-based 636 if (!parseLong(dateString, &newPosStr, 10, &day)) 637 return std::numeric_limits<double>::quiet_NaN(); 638 if (day < 1 || day > 31) 639 return std::numeric_limits<double>::quiet_NaN(); 640 dateString = newPosStr; 641 if (*dateString == '/') 642 dateString++; 643 if (!*dateString) 644 return std::numeric_limits<double>::quiet_NaN(); 645 } else { 646 if (*dateString == '-') 647 dateString++; 648 649 skipSpacesAndComments(dateString); 650 651 if (*dateString == ',') 652 dateString++; 653 654 if (month == -1) { // not found yet 655 month = findMonth(dateString); 656 if (month == -1) 657 return std::numeric_limits<double>::quiet_NaN(); 658 659 while (*dateString && *dateString != '-' && *dateString != ',' && !isASCIISpace(*dateString)) 660 dateString++; 661 662 if (!*dateString) 663 return std::numeric_limits<double>::quiet_NaN(); 664 665 // '-99 23:12:40 GMT' 666 if (*dateString != '-' && *dateString != '/' && *dateString != ',' && !isASCIISpace(*dateString)) 667 return std::numeric_limits<double>::quiet_NaN(); 668 dateString++; 669 } 670 } 671 672 if (month < 0 || month > 11) 673 return std::numeric_limits<double>::quiet_NaN(); 674 675 // '99 23:12:40 GMT' 676 if (year <= 0 && *dateString) { 677 if (!parseInt(dateString, &newPosStr, 10, &year)) 678 return std::numeric_limits<double>::quiet_NaN(); 679 } 680 681 // Don't fail if the time is missing. 682 long hour = 0; 683 long minute = 0; 684 long second = 0; 685 if (!*newPosStr) 686 dateString = newPosStr; 687 else { 688 // ' 23:12:40 GMT' 689 if (!(isASCIISpace(*newPosStr) || *newPosStr == ',')) { 690 if (*newPosStr != ':') 691 return std::numeric_limits<double>::quiet_NaN(); 692 // There was no year; the number was the hour. 693 year = -1; 694 } else { 695 // in the normal case (we parsed the year), advance to the next number 696 dateString = ++newPosStr; 697 skipSpacesAndComments(dateString); 698 } 699 700 parseLong(dateString, &newPosStr, 10, &hour); 701 // Do not check for errno here since we want to continue 702 // even if errno was set becasue we are still looking 703 // for the timezone! 704 705 // Read a number? If not, this might be a timezone name. 706 if (newPosStr != dateString) { 707 dateString = newPosStr; 708 709 if (hour < 0 || hour > 23) 710 return std::numeric_limits<double>::quiet_NaN(); 711 712 if (!*dateString) 713 return std::numeric_limits<double>::quiet_NaN(); 714 715 // ':12:40 GMT' 716 if (*dateString++ != ':') 717 return std::numeric_limits<double>::quiet_NaN(); 718 719 if (!parseLong(dateString, &newPosStr, 10, &minute)) 720 return std::numeric_limits<double>::quiet_NaN(); 721 dateString = newPosStr; 722 723 if (minute < 0 || minute > 59) 724 return std::numeric_limits<double>::quiet_NaN(); 725 726 // ':40 GMT' 727 if (*dateString && *dateString != ':' && !isASCIISpace(*dateString)) 728 return std::numeric_limits<double>::quiet_NaN(); 729 730 // seconds are optional in rfc822 + rfc2822 731 if (*dateString ==':') { 732 dateString++; 733 734 if (!parseLong(dateString, &newPosStr, 10, &second)) 735 return std::numeric_limits<double>::quiet_NaN(); 736 dateString = newPosStr; 737 738 if (second < 0 || second > 59) 739 return std::numeric_limits<double>::quiet_NaN(); 740 } 741 742 skipSpacesAndComments(dateString); 743 744 if (strncasecmp(dateString, "AM", 2) == 0) { 745 if (hour > 12) 746 return std::numeric_limits<double>::quiet_NaN(); 747 if (hour == 12) 748 hour = 0; 749 dateString += 2; 750 skipSpacesAndComments(dateString); 751 } else if (strncasecmp(dateString, "PM", 2) == 0) { 752 if (hour > 12) 753 return std::numeric_limits<double>::quiet_NaN(); 754 if (hour != 12) 755 hour += 12; 756 dateString += 2; 757 skipSpacesAndComments(dateString); 758 } 759 } 760 } 761 762 // The year may be after the time but before the time zone. 763 if (isASCIIDigit(*dateString) && year == -1) { 764 if (!parseInt(dateString, &newPosStr, 10, &year)) 765 return std::numeric_limits<double>::quiet_NaN(); 766 dateString = newPosStr; 767 skipSpacesAndComments(dateString); 768 } 769 770 // Don't fail if the time zone is missing. 771 // Some websites omit the time zone (4275206). 772 if (*dateString) { 773 if (strncasecmp(dateString, "GMT", 3) == 0 || strncasecmp(dateString, "UTC", 3) == 0) { 774 dateString += 3; 775 haveTZ = true; 776 } 777 778 if (*dateString == '+' || *dateString == '-') { 779 int o; 780 if (!parseInt(dateString, &newPosStr, 10, &o)) 781 return std::numeric_limits<double>::quiet_NaN(); 782 dateString = newPosStr; 783 784 if (o < -9959 || o > 9959) 785 return std::numeric_limits<double>::quiet_NaN(); 786 787 int sgn = (o < 0) ? -1 : 1; 788 o = abs(o); 789 if (*dateString != ':') { 790 if (o >= 24) 791 offset = ((o / 100) * 60 + (o % 100)) * sgn; 792 else 793 offset = o * 60 * sgn; 794 } else { // GMT+05:00 795 ++dateString; // skip the ':' 796 int o2; 797 if (!parseInt(dateString, &newPosStr, 10, &o2)) 798 return std::numeric_limits<double>::quiet_NaN(); 799 dateString = newPosStr; 800 offset = (o * 60 + o2) * sgn; 801 } 802 haveTZ = true; 803 } else { 804 for (size_t i = 0; i < WTF_ARRAY_LENGTH(known_zones); ++i) { 805 if (0 == strncasecmp(dateString, known_zones[i].tzName, strlen(known_zones[i].tzName))) { 806 offset = known_zones[i].tzOffset; 807 dateString += strlen(known_zones[i].tzName); 808 haveTZ = true; 809 break; 810 } 811 } 812 } 813 } 814 815 skipSpacesAndComments(dateString); 816 817 if (*dateString && year == -1) { 818 if (!parseInt(dateString, &newPosStr, 10, &year)) 819 return std::numeric_limits<double>::quiet_NaN(); 820 dateString = newPosStr; 821 skipSpacesAndComments(dateString); 822 } 823 824 // Trailing garbage 825 if (*dateString) 826 return std::numeric_limits<double>::quiet_NaN(); 827 828 // Y2K: Handle 2 digit years. 829 if (year >= 0 && year < 100) { 830 if (year < 50) 831 year += 2000; 832 else 833 year += 1900; 834 } 835 836 return ymdhmsToSeconds(year, month + 1, day, hour, minute, second) * msPerSecond; 837 } 838 839 double parseDateFromNullTerminatedCharacters(const char* dateString) 840 { 841 bool haveTZ; 842 int offset; 843 double ms = parseDateFromNullTerminatedCharacters(dateString, haveTZ, offset); 844 if (std::isnan(ms)) 845 return std::numeric_limits<double>::quiet_NaN(); 846 847 // fall back to local timezone 848 if (!haveTZ) { 849 double utcOffset = calculateUTCOffset(); 850 double dstOffset = calculateDSTOffset(ms, utcOffset); 851 offset = (utcOffset + dstOffset) / msPerMinute; 852 } 853 return ms - (offset * msPerMinute); 854 } 855 856 // See http://tools.ietf.org/html/rfc2822#section-3.3 for more information. 857 String makeRFC2822DateString(unsigned dayOfWeek, unsigned day, unsigned month, unsigned year, unsigned hours, unsigned minutes, unsigned seconds, int utcOffset) 858 { 859 StringBuilder stringBuilder; 860 stringBuilder.append(weekdayName[dayOfWeek]); 861 stringBuilder.appendLiteral(", "); 862 stringBuilder.appendNumber(day); 863 stringBuilder.append(' '); 864 stringBuilder.append(monthName[month]); 865 stringBuilder.append(' '); 866 stringBuilder.appendNumber(year); 867 stringBuilder.append(' '); 868 869 stringBuilder.append(twoDigitStringFromNumber(hours)); 870 stringBuilder.append(':'); 871 stringBuilder.append(twoDigitStringFromNumber(minutes)); 872 stringBuilder.append(':'); 873 stringBuilder.append(twoDigitStringFromNumber(seconds)); 874 stringBuilder.append(' '); 875 876 stringBuilder.append(utcOffset > 0 ? '+' : '-'); 877 int absoluteUTCOffset = abs(utcOffset); 878 stringBuilder.append(twoDigitStringFromNumber(absoluteUTCOffset / 60)); 879 stringBuilder.append(twoDigitStringFromNumber(absoluteUTCOffset % 60)); 880 881 return stringBuilder.toString(); 882 } 883 884 } // namespace WTF 885
