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