source: webkit/trunk/JavaScriptCore/runtime/DateMath.cpp@ 43165

Last change on this file since 43165 was 42037, checked in by Simon Hausmann, 16 years ago

2009-03-27 Laszlo Gombos <Laszlo Gombos>

Reviewed by Darin Adler.

Bug 24884: Include strings.h for strcasecmp()
​https://bugs.webkit.org/show_bug.cgi?id=24884
  • Property svn:eol-style set to native
File size: 27.8 KB
Line 
1/*
2 * Copyright (C) 1999-2000 Harri Porten ([email protected])
3 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
4 *
5 * The Original Code is Mozilla Communicator client code, released
6 * March 31, 1998.
7 *
8 * The Initial Developer of the Original Code is
9 * Netscape Communications Corporation.
10 * Portions created by the Initial Developer are Copyright (C) 1998
11 * the Initial Developer. All Rights Reserved.
12 *
13 * This library is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU Lesser General Public
15 * License as published by the Free Software Foundation; either
16 * version 2.1 of the License, or (at your option) any later version.
17 *
18 * This library is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * Lesser General Public License for more details.
22 *
23 * You should have received a copy of the GNU Lesser General Public
24 * License along with this library; if not, write to the Free Software
25 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 *
27 * Alternatively, the contents of this file may be used under the terms
28 * of either the Mozilla Public License Version 1.1, found at
29 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
30 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
31 * (the "GPL"), in which case the provisions of the MPL or the GPL are
32 * applicable instead of those above. If you wish to allow use of your
33 * version of this file only under the terms of one of those two
34 * licenses (the MPL or the GPL) and not to allow others to use your
35 * version of this file under the LGPL, indicate your decision by
36 * deletingthe provisions above and replace them with the notice and
37 * other provisions required by the MPL or the GPL, as the case may be.
38 * If you do not delete the provisions above, a recipient may use your
39 * version of this file under any of the LGPL, the MPL or the GPL.
40 */
41
42#include "config.h"
43#include "DateMath.h"
44
45#include "JSNumberCell.h"
46#include <math.h>
47#include <stdint.h>
48#include <time.h>
49#include <wtf/ASCIICType.h>
50#include <wtf/Assertions.h>
51#include <wtf/CurrentTime.h>
52#include <wtf/MathExtras.h>
53#include <wtf/StringExtras.h>
54
55#if HAVE(ERRNO_H)
56#include <errno.h>
57#endif
58
59#if PLATFORM(DARWIN)
60#include <notify.h>
61#endif
62
63#if HAVE(SYS_TIME_H)
64#include <sys/time.h>
65#endif
66
67#if HAVE(SYS_TIMEB_H)
68#include <sys/timeb.h>
69#endif
70
71using namespace WTF;
72
73namespace JSC {
74
75/* Constants */
76
77static const double minutesPerDay = 24.0 * 60.0;
78static const double secondsPerDay = 24.0 * 60.0 * 60.0;
79static const double secondsPerYear = 24.0 * 60.0 * 60.0 * 365.0;
80
81static const double usecPerSec = 1000000.0;
82
83static const double maxUnixTime = 2145859200.0; // 12/31/2037
84
85// Day of year for the first day of each month, where index 0 is January, and day 0 is January 1.
86// First for non-leap years, then for leap years.
87static const int firstDayOfMonth[2][12] = {
88 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
89 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
90};
91
92static inline bool isLeapYear(int year)
93{
94 if (year % 4 != 0)
95 return false;
96 if (year % 400 == 0)
97 return true;
98 if (year % 100 == 0)
99 return false;
100 return true;
101}
102
103static inline int daysInYear(int year)
104{
105 return 365 + isLeapYear(year);
106}
107
108static inline double daysFrom1970ToYear(int year)
109{
110 // The Gregorian Calendar rules for leap years:
111 // Every fourth year is a leap year. 2004, 2008, and 2012 are leap years.
112 // However, every hundredth year is not a leap year. 1900 and 2100 are not leap years.
113 // Every four hundred years, there's a leap year after all. 2000 and 2400 are leap years.
114
115 static const int leapDaysBefore1971By4Rule = 1970 / 4;
116 static const int excludedLeapDaysBefore1971By100Rule = 1970 / 100;
117 static const int leapDaysBefore1971By400Rule = 1970 / 400;
118
119 const double yearMinusOne = year - 1;
120 const double yearsToAddBy4Rule = floor(yearMinusOne / 4.0) - leapDaysBefore1971By4Rule;
121 const double yearsToExcludeBy100Rule = floor(yearMinusOne / 100.0) - excludedLeapDaysBefore1971By100Rule;
122 const double yearsToAddBy400Rule = floor(yearMinusOne / 400.0) - leapDaysBefore1971By400Rule;
123
124 return 365.0 * (year - 1970) + yearsToAddBy4Rule - yearsToExcludeBy100Rule + yearsToAddBy400Rule;
125}
126
127static inline double msToDays(double ms)
128{
129 return floor(ms / msPerDay);
130}
131
132static inline int msToYear(double ms)
133{
134 int approxYear = static_cast<int>(floor(ms / (msPerDay * 365.2425)) + 1970);
135 double msFromApproxYearTo1970 = msPerDay * daysFrom1970ToYear(approxYear);
136 if (msFromApproxYearTo1970 > ms)
137 return approxYear - 1;
138 if (msFromApproxYearTo1970 + msPerDay * daysInYear(approxYear) <= ms)
139 return approxYear + 1;
140 return approxYear;
141}
142
143static inline int dayInYear(double ms, int year)
144{
145 return static_cast<int>(msToDays(ms) - daysFrom1970ToYear(year));
146}
147
148static inline double msToMilliseconds(double ms)
149{
150 double result = fmod(ms, msPerDay);
151 if (result < 0)
152 result += msPerDay;
153 return result;
154}
155
156// 0: Sunday, 1: Monday, etc.
157static inline int msToWeekDay(double ms)
158{
159 int wd = (static_cast<int>(msToDays(ms)) + 4) % 7;
160 if (wd < 0)
161 wd += 7;
162 return wd;
163}
164
165static inline int msToSeconds(double ms)
166{
167 double result = fmod(floor(ms / msPerSecond), secondsPerMinute);
168 if (result < 0)
169 result += secondsPerMinute;
170 return static_cast<int>(result);
171}
172
173static inline int msToMinutes(double ms)
174{
175 double result = fmod(floor(ms / msPerMinute), minutesPerHour);
176 if (result < 0)
177 result += minutesPerHour;
178 return static_cast<int>(result);
179}
180
181static inline int msToHours(double ms)
182{
183 double result = fmod(floor(ms/msPerHour), hoursPerDay);
184 if (result < 0)
185 result += hoursPerDay;
186 return static_cast<int>(result);
187}
188
189static inline int monthFromDayInYear(int dayInYear, bool leapYear)
190{
191 const int d = dayInYear;
192 int step;
193
194 if (d < (step = 31))
195 return 0;
196 step += (leapYear ? 29 : 28);
197 if (d < step)
198 return 1;
199 if (d < (step += 31))
200 return 2;
201 if (d < (step += 30))
202 return 3;
203 if (d < (step += 31))
204 return 4;
205 if (d < (step += 30))
206 return 5;
207 if (d < (step += 31))
208 return 6;
209 if (d < (step += 31))
210 return 7;
211 if (d < (step += 30))
212 return 8;
213 if (d < (step += 31))
214 return 9;
215 if (d < (step += 30))
216 return 10;
217 return 11;
218}
219
220static inline bool checkMonth(int dayInYear, int& startDayOfThisMonth, int& startDayOfNextMonth, int daysInThisMonth)
221{
222 startDayOfThisMonth = startDayOfNextMonth;
223 startDayOfNextMonth += daysInThisMonth;
224 return (dayInYear <= startDayOfNextMonth);
225}
226
227static inline int dayInMonthFromDayInYear(int dayInYear, bool leapYear)
228{
229 const int d = dayInYear;
230 int step;
231 int next = 30;
232
233 if (d <= next)
234 return d + 1;
235 const int daysInFeb = (leapYear ? 29 : 28);
236 if (checkMonth(d, step, next, daysInFeb))
237 return d - step;
238 if (checkMonth(d, step, next, 31))
239 return d - step;
240 if (checkMonth(d, step, next, 30))
241 return d - step;
242 if (checkMonth(d, step, next, 31))
243 return d - step;
244 if (checkMonth(d, step, next, 30))
245 return d - step;
246 if (checkMonth(d, step, next, 31))
247 return d - step;
248 if (checkMonth(d, step, next, 31))
249 return d - step;
250 if (checkMonth(d, step, next, 30))
251 return d - step;
252 if (checkMonth(d, step, next, 31))
253 return d - step;
254 if (checkMonth(d, step, next, 30))
255 return d - step;
256 step = next;
257 return d - step;
258}
259
260static inline int monthToDayInYear(int month, bool isLeapYear)
261{
262 return firstDayOfMonth[isLeapYear][month];
263}
264
265static inline double timeToMS(double hour, double min, double sec, double ms)
266{
267 return (((hour * minutesPerHour + min) * secondsPerMinute + sec) * msPerSecond + ms);
268}
269
270static int dateToDayInYear(int year, int month, int day)
271{
272 year += month / 12;
273
274 month %= 12;
275 if (month < 0) {
276 month += 12;
277 --year;
278 }
279
280 int yearday = static_cast<int>(floor(daysFrom1970ToYear(year)));
281 int monthday = monthToDayInYear(month, isLeapYear(year));
282
283 return yearday + monthday + day - 1;
284}
285
286double getCurrentUTCTime()
287{
288 return floor(getCurrentUTCTimeWithMicroseconds());
289}
290
291// Returns current time in milliseconds since 1 Jan 1970.
292double getCurrentUTCTimeWithMicroseconds()
293{
294 return currentTime() * 1000.0;
295}
296
297void getLocalTime(const time_t* localTime, struct tm* localTM)
298{
299#if COMPILER(MSVC7) || COMPILER(MINGW) || PLATFORM(WIN_CE)
300 *localTM = *localtime(localTime);
301#elif COMPILER(MSVC)
302 localtime_s(localTM, localTime);
303#else
304 localtime_r(localTime, localTM);
305#endif
306}
307
308// There is a hard limit at 2038 that we currently do not have a workaround
309// for (rdar://problem/5052975).
310static inline int maximumYearForDST()
311{
312 return 2037;
313}
314
315static inline int minimumYearForDST()
316{
317 // Because of the 2038 issue (see maximumYearForDST) if the current year is
318 // greater than the max year minus 27 (2010), we want to use the max year
319 // minus 27 instead, to ensure there is a range of 28 years that all years
320 // can map to.
321 return std::min(msToYear(getCurrentUTCTime()), maximumYearForDST() - 27) ;
322}
323
324/*
325 * Find an equivalent year for the one given, where equivalence is deterined by
326 * the two years having the same leapness and the first day of the year, falling
327 * on the same day of the week.
328 *
329 * This function returns a year between this current year and 2037, however this
330 * function will potentially return incorrect results if the current year is after
331 * 2010, (rdar://problem/5052975), if the year passed in is before 1900 or after
332 * 2100, (rdar://problem/5055038).
333 */
334int equivalentYearForDST(int year)
335{
336 // It is ok if the cached year is not the current year as long as the rules
337 // for DST did not change between the two years; if they did the app would need
338 // to be restarted.
339 static int minYear = minimumYearForDST();
340 int maxYear = maximumYearForDST();
341
342 int difference;
343 if (year > maxYear)
344 difference = minYear - year;
345 else if (year < minYear)
346 difference = maxYear - year;
347 else
348 return year;
349
350 int quotient = difference / 28;
351 int product = (quotient) * 28;
352
353 year += product;
354 ASSERT((year >= minYear && year <= maxYear) || (product - year == static_cast<int>(NaN)));
355 return year;
356}
357
358static int32_t calculateUTCOffset()
359{
360 tm localt;
361 memset(&localt, 0, sizeof(localt));
362
363 // get the difference between this time zone and UTC on Jan 01, 2000 12:00:00 AM
364 localt.tm_mday = 1;
365 localt.tm_year = 100;
366 time_t utcOffset = 946684800 - mktime(&localt);
367
368 return static_cast<int32_t>(utcOffset * 1000);
369}
370
371#if PLATFORM(DARWIN)
372static int32_t s_cachedUTCOffset; // In milliseconds. An assumption here is that access to an int32_t variable is atomic on platforms that take this code path.
373static bool s_haveCachedUTCOffset;
374static int s_notificationToken;
375#endif
376
377/*
378 * Get the difference in milliseconds between this time zone and UTC (GMT)
379 * NOT including DST.
380 */
381double getUTCOffset()
382{
383#if PLATFORM(DARWIN)
384 if (s_haveCachedUTCOffset) {
385 int notified;
386 uint32_t status = notify_check(s_notificationToken, &notified);
387 if (status == NOTIFY_STATUS_OK && !notified)
388 return s_cachedUTCOffset;
389 }
390#endif
391
392 int32_t utcOffset = calculateUTCOffset();
393
394#if PLATFORM(DARWIN)
395 // Theoretically, it is possible that several threads will be executing this code at once, in which case we will have a race condition,
396 // and a newer value may be overwritten. In practice, time zones don't change that often.
397 s_cachedUTCOffset = utcOffset;
398#endif
399
400 return utcOffset;
401}
402
403/*
404 * Get the DST offset for the time passed in. Takes
405 * seconds (not milliseconds) and cannot handle dates before 1970
406 * on some OS'
407 */
408static double getDSTOffsetSimple(double localTimeSeconds, double utcOffset)
409{
410 if (localTimeSeconds > maxUnixTime)
411 localTimeSeconds = maxUnixTime;
412 else if (localTimeSeconds < 0) // Go ahead a day to make localtime work (does not work with 0)
413 localTimeSeconds += secondsPerDay;
414
415 //input is UTC so we have to shift back to local time to determine DST thus the + getUTCOffset()
416 double offsetTime = (localTimeSeconds * msPerSecond) + utcOffset;
417
418 // Offset from UTC but doesn't include DST obviously
419 int offsetHour = msToHours(offsetTime);
420 int offsetMinute = msToMinutes(offsetTime);
421
422 // FIXME: time_t has a potential problem in 2038
423 time_t localTime = static_cast<time_t>(localTimeSeconds);
424
425 tm localTM;
426 getLocalTime(&localTime, &localTM);
427
428 double diff = ((localTM.tm_hour - offsetHour) * secondsPerHour) + ((localTM.tm_min - offsetMinute) * 60);
429
430 if (diff < 0)
431 diff += secondsPerDay;
432
433 return (diff * msPerSecond);
434}
435
436// Get the DST offset, given a time in UTC
437static double getDSTOffset(double ms, double utcOffset)
438{
439 // On Mac OS X, the call to localtime (see getDSTOffsetSimple) will return historically accurate
440 // DST information (e.g. New Zealand did not have DST from 1946 to 1974) however the JavaScript
441 // standard explicitly dictates that historical information should not be considered when
442 // determining DST. For this reason we shift away from years that localtime can handle but would
443 // return historically accurate information.
444 int year = msToYear(ms);
445 int equivalentYear = equivalentYearForDST(year);
446 if (year != equivalentYear) {
447 bool leapYear = isLeapYear(year);
448 int dayInYearLocal = dayInYear(ms, year);
449 int dayInMonth = dayInMonthFromDayInYear(dayInYearLocal, leapYear);
450 int month = monthFromDayInYear(dayInYearLocal, leapYear);
451 int day = dateToDayInYear(equivalentYear, month, dayInMonth);
452 ms = (day * msPerDay) + msToMilliseconds(ms);
453 }
454
455 return getDSTOffsetSimple(ms / msPerSecond, utcOffset);
456}
457
458double gregorianDateTimeToMS(const GregorianDateTime& t, double milliSeconds, bool inputIsUTC)
459{
460 int day = dateToDayInYear(t.year + 1900, t.month, t.monthDay);
461 double ms = timeToMS(t.hour, t.minute, t.second, milliSeconds);
462 double result = (day * msPerDay) + ms;
463
464 if (!inputIsUTC) { // convert to UTC
465 double utcOffset = getUTCOffset();
466 result -= utcOffset;
467 result -= getDSTOffset(result, utcOffset);
468 }
469
470 return result;
471}
472
473void msToGregorianDateTime(double ms, bool outputIsUTC, GregorianDateTime& tm)
474{
475 // input is UTC
476 double dstOff = 0.0;
477 const double utcOff = getUTCOffset();
478
479 if (!outputIsUTC) { // convert to local time
480 dstOff = getDSTOffset(ms, utcOff);
481 ms += dstOff + utcOff;
482 }
483
484 const int year = msToYear(ms);
485 tm.second = msToSeconds(ms);
486 tm.minute = msToMinutes(ms);
487 tm.hour = msToHours(ms);
488 tm.weekDay = msToWeekDay(ms);
489 tm.yearDay = dayInYear(ms, year);
490 tm.monthDay = dayInMonthFromDayInYear(tm.yearDay, isLeapYear(year));
491 tm.month = monthFromDayInYear(tm.yearDay, isLeapYear(year));
492 tm.year = year - 1900;
493 tm.isDST = dstOff != 0.0;
494
495 tm.utcOffset = static_cast<long>((dstOff + utcOff) / msPerSecond);
496 tm.timeZone = NULL;
497}
498
499void initDateMath()
500{
501#ifndef NDEBUG
502 static bool alreadyInitialized;
503 ASSERT(!alreadyInitialized++);
504#endif
505
506 equivalentYearForDST(2000); // Need to call once to initialize a static used in this function.
507#if PLATFORM(DARWIN)
508 // Register for a notification whenever the time zone changes.
509 uint32_t status = notify_register_check("com.apple.system.timezone", &s_notificationToken);
510 if (status == NOTIFY_STATUS_OK) {
511 s_cachedUTCOffset = calculateUTCOffset();
512 s_haveCachedUTCOffset = true;
513 }
514#endif
515}
516
517static inline double ymdhmsToSeconds(long year, int mon, int day, int hour, int minute, int second)
518{
519 double days = (day - 32075)
520 + floor(1461 * (year + 4800.0 + (mon - 14) / 12) / 4)
521 + 367 * (mon - 2 - (mon - 14) / 12 * 12) / 12
522 - floor(3 * ((year + 4900.0 + (mon - 14) / 12) / 100) / 4)
523 - 2440588;
524 return ((days * hoursPerDay + hour) * minutesPerHour + minute) * secondsPerMinute + second;
525}
526
527// We follow the recommendation of RFC 2822 to consider all
528// obsolete time zones not listed here equivalent to "-0000".
529static const struct KnownZone {
530#if !PLATFORM(WIN_OS)
531 const
532#endif
533 char tzName[4];
534 int tzOffset;
535} known_zones[] = {
536 { "UT", 0 },
537 { "GMT", 0 },
538 { "EST", -300 },
539 { "EDT", -240 },
540 { "CST", -360 },
541 { "CDT", -300 },
542 { "MST", -420 },
543 { "MDT", -360 },
544 { "PST", -480 },
545 { "PDT", -420 }
546};
547
548inline static void skipSpacesAndComments(const char*& s)
549{
550 int nesting = 0;
551 char ch;
552 while ((ch = *s)) {
553 if (!isASCIISpace(ch)) {
554 if (ch == '(')
555 nesting++;
556 else if (ch == ')' && nesting > 0)
557 nesting--;
558 else if (nesting == 0)
559 break;
560 }
561 s++;
562 }
563}
564
565// returns 0-11 (Jan-Dec); -1 on failure
566static int findMonth(const char* monthStr)
567{
568 ASSERT(monthStr);
569 char needle[4];
570 for (int i = 0; i < 3; ++i) {
571 if (!*monthStr)
572 return -1;
573 needle[i] = static_cast<char>(toASCIILower(*monthStr++));
574 }
575 needle[3] = '\0';
576 const char *haystack = "janfebmaraprmayjunjulaugsepoctnovdec";
577 const char *str = strstr(haystack, needle);
578 if (str) {
579 int position = static_cast<int>(str - haystack);
580 if (position % 3 == 0)
581 return position / 3;
582 }
583 return -1;
584}
585
586static bool parseLong(const char* string, char** stopPosition, int base, long* result)
587{
588 *result = strtol(string, stopPosition, base);
589 // Avoid the use of errno as it is not available on Windows CE
590 if (string == *stopPosition || *result == LONG_MIN || *result == LONG_MAX)
591 return false;
592 return true;
593}
594
595double parseDate(const UString &date)
596{
597 // This parses a date in the form:
598 // Tuesday, 09-Nov-99 23:12:40 GMT
599 // or
600 // Sat, 01-Jan-2000 08:00:00 GMT
601 // or
602 // Sat, 01 Jan 2000 08:00:00 GMT
603 // or
604 // 01 Jan 99 22:00 +0100 (exceptions in rfc822/rfc2822)
605 // ### non RFC formats, added for Javascript:
606 // [Wednesday] January 09 1999 23:12:40 GMT
607 // [Wednesday] January 09 23:12:40 GMT 1999
608 //
609 // We ignore the weekday.
610
611 CString dateCString = date.UTF8String();
612 const char *dateString = dateCString.c_str();
613
614 // Skip leading space
615 skipSpacesAndComments(dateString);
616
617 long month = -1;
618 const char *wordStart = dateString;
619 // Check contents of first words if not number
620 while (*dateString && !isASCIIDigit(*dateString)) {
621 if (isASCIISpace(*dateString) || *dateString == '(') {
622 if (dateString - wordStart >= 3)
623 month = findMonth(wordStart);
624 skipSpacesAndComments(dateString);
625 wordStart = dateString;
626 } else
627 dateString++;
628 }
629
630 // Missing delimiter between month and day (like "January29")?
631 if (month == -1 && wordStart != dateString)
632 month = findMonth(wordStart);
633
634 skipSpacesAndComments(dateString);
635
636 if (!*dateString)
637 return NaN;
638
639 // ' 09-Nov-99 23:12:40 GMT'
640 char* newPosStr;
641 long day;
642 if (!parseLong(dateString, &newPosStr, 10, &day))
643 return NaN;
644 dateString = newPosStr;
645
646 if (!*dateString)
647 return NaN;
648
649 if (day < 0)
650 return NaN;
651
652 long year = 0;
653 if (day > 31) {
654 // ### where is the boundary and what happens below?
655 if (*dateString != '/')
656 return NaN;
657 // looks like a YYYY/MM/DD date
658 if (!*++dateString)
659 return NaN;
660 year = day;
661 if (!parseLong(dateString, &newPosStr, 10, &month))
662 return NaN;
663 month -= 1;
664 dateString = newPosStr;
665 if (*dateString++ != '/' || !*dateString)
666 return NaN;
667 if (!parseLong(dateString, &newPosStr, 10, &day))
668 return NaN;
669 dateString = newPosStr;
670 } else if (*dateString == '/' && month == -1) {
671 dateString++;
672 // This looks like a MM/DD/YYYY date, not an RFC date.
673 month = day - 1; // 0-based
674 if (!parseLong(dateString, &newPosStr, 10, &day))
675 return NaN;
676 if (day < 1 || day > 31)
677 return NaN;
678 dateString = newPosStr;
679 if (*dateString == '/')
680 dateString++;
681 if (!*dateString)
682 return NaN;
683 } else {
684 if (*dateString == '-')
685 dateString++;
686
687 skipSpacesAndComments(dateString);
688
689 if (*dateString == ',')
690 dateString++;
691
692 if (month == -1) { // not found yet
693 month = findMonth(dateString);
694 if (month == -1)
695 return NaN;
696
697 while (*dateString && *dateString != '-' && *dateString != ',' && !isASCIISpace(*dateString))
698 dateString++;
699
700 if (!*dateString)
701 return NaN;
702
703 // '-99 23:12:40 GMT'
704 if (*dateString != '-' && *dateString != '/' && *dateString != ',' && !isASCIISpace(*dateString))
705 return NaN;
706 dateString++;
707 }
708 }
709
710 if (month < 0 || month > 11)
711 return NaN;
712
713 // '99 23:12:40 GMT'
714 if (year <= 0 && *dateString) {
715 if (!parseLong(dateString, &newPosStr, 10, &year))
716 return NaN;
717 }
718
719 // Don't fail if the time is missing.
720 long hour = 0;
721 long minute = 0;
722 long second = 0;
723 if (!*newPosStr)
724 dateString = newPosStr;
725 else {
726 // ' 23:12:40 GMT'
727 if (!(isASCIISpace(*newPosStr) || *newPosStr == ',')) {
728 if (*newPosStr != ':')
729 return NaN;
730 // There was no year; the number was the hour.
731 year = -1;
732 } else {
733 // in the normal case (we parsed the year), advance to the next number
734 dateString = ++newPosStr;
735 skipSpacesAndComments(dateString);
736 }
737
738 parseLong(dateString, &newPosStr, 10, &hour);
739 // Do not check for errno here since we want to continue
740 // even if errno was set becasue we are still looking
741 // for the timezone!
742
743 // Read a number? If not, this might be a timezone name.
744 if (newPosStr != dateString) {
745 dateString = newPosStr;
746
747 if (hour < 0 || hour > 23)
748 return NaN;
749
750 if (!*dateString)
751 return NaN;
752
753 // ':12:40 GMT'
754 if (*dateString++ != ':')
755 return NaN;
756
757 if (!parseLong(dateString, &newPosStr, 10, &minute))
758 return NaN;
759 dateString = newPosStr;
760
761 if (minute < 0 || minute > 59)
762 return NaN;
763
764 // ':40 GMT'
765 if (*dateString && *dateString != ':' && !isASCIISpace(*dateString))
766 return NaN;
767
768 // seconds are optional in rfc822 + rfc2822
769 if (*dateString ==':') {
770 dateString++;
771
772 if (!parseLong(dateString, &newPosStr, 10, &second))
773 return NaN;
774 dateString = newPosStr;
775
776 if (second < 0 || second > 59)
777 return NaN;
778 }
779
780 skipSpacesAndComments(dateString);
781
782 if (strncasecmp(dateString, "AM", 2) == 0) {
783 if (hour > 12)
784 return NaN;
785 if (hour == 12)
786 hour = 0;
787 dateString += 2;
788 skipSpacesAndComments(dateString);
789 } else if (strncasecmp(dateString, "PM", 2) == 0) {
790 if (hour > 12)
791 return NaN;
792 if (hour != 12)
793 hour += 12;
794 dateString += 2;
795 skipSpacesAndComments(dateString);
796 }
797 }
798 }
799
800 bool haveTZ = false;
801 int offset = 0;
802
803 // Don't fail if the time zone is missing.
804 // Some websites omit the time zone (4275206).
805 if (*dateString) {
806 if (strncasecmp(dateString, "GMT", 3) == 0 || strncasecmp(dateString, "UTC", 3) == 0) {
807 dateString += 3;
808 haveTZ = true;
809 }
810
811 if (*dateString == '+' || *dateString == '-') {
812 long o;
813 if (!parseLong(dateString, &newPosStr, 10, &o))
814 return NaN;
815 dateString = newPosStr;
816
817 if (o < -9959 || o > 9959)
818 return NaN;
819
820 int sgn = (o < 0) ? -1 : 1;
821 o = abs(o);
822 if (*dateString != ':') {
823 offset = ((o / 100) * 60 + (o % 100)) * sgn;
824 } else { // GMT+05:00
825 long o2;
826 if (!parseLong(dateString, &newPosStr, 10, &o2))
827 return NaN;
828 dateString = newPosStr;
829 offset = (o * 60 + o2) * sgn;
830 }
831 haveTZ = true;
832 } else {
833 for (int i = 0; i < int(sizeof(known_zones) / sizeof(KnownZone)); i++) {
834 if (0 == strncasecmp(dateString, known_zones[i].tzName, strlen(known_zones[i].tzName))) {
835 offset = known_zones[i].tzOffset;
836 dateString += strlen(known_zones[i].tzName);
837 haveTZ = true;
838 break;
839 }
840 }
841 }
842 }
843
844 skipSpacesAndComments(dateString);
845
846 if (*dateString && year == -1) {
847 if (!parseLong(dateString, &newPosStr, 10, &year))
848 return NaN;
849 dateString = newPosStr;
850 }
851
852 skipSpacesAndComments(dateString);
853
854 // Trailing garbage
855 if (*dateString)
856 return NaN;
857
858 // Y2K: Handle 2 digit years.
859 if (year >= 0 && year < 100) {
860 if (year < 50)
861 year += 2000;
862 else
863 year += 1900;
864 }
865
866 // fall back to local timezone
867 if (!haveTZ) {
868 GregorianDateTime t;
869 t.monthDay = day;
870 t.month = month;
871 t.year = year - 1900;
872 t.isDST = -1;
873 t.second = second;
874 t.minute = minute;
875 t.hour = hour;
876
877 // Use our gregorianDateTimeToMS() rather than mktime() as the latter can't handle the full year range.
878 return gregorianDateTimeToMS(t, 0, false);
879 }
880
881 return (ymdhmsToSeconds(year, month + 1, day, hour, minute, second) - (offset * 60.0)) * msPerSecond;
882}
883
884double timeClip(double t)
885{
886 if (!isfinite(t))
887 return NaN;
888 if (fabs(t) > 8.64E15)
889 return NaN;
890 return trunc(t);
891}
892
893UString formatDate(const GregorianDateTime &t)
894{
895 char buffer[100];
896 snprintf(buffer, sizeof(buffer), "%s %s %02d %04d",
897 weekdayName[(t.weekDay + 6) % 7],
898 monthName[t.month], t.monthDay, t.year + 1900);
899 return buffer;
900}
901
902UString formatDateUTCVariant(const GregorianDateTime &t)
903{
904 char buffer[100];
905 snprintf(buffer, sizeof(buffer), "%s, %02d %s %04d",
906 weekdayName[(t.weekDay + 6) % 7],
907 t.monthDay, monthName[t.month], t.year + 1900);
908 return buffer;
909}
910
911UString formatTime(const GregorianDateTime &t, bool utc)
912{
913 char buffer[100];
914 if (utc) {
915 snprintf(buffer, sizeof(buffer), "%02d:%02d:%02d GMT", t.hour, t.minute, t.second);
916 } else {
917 int offset = abs(gmtoffset(t));
918 char timeZoneName[70];
919 struct tm gtm = t;
920 strftime(timeZoneName, sizeof(timeZoneName), "%Z", &gtm);
921
922 if (timeZoneName[0]) {
923 snprintf(buffer, sizeof(buffer), "%02d:%02d:%02d GMT%c%02d%02d (%s)",
924 t.hour, t.minute, t.second,
925 gmtoffset(t) < 0 ? '-' : '+', offset / (60*60), (offset / 60) % 60, timeZoneName);
926 } else {
927 snprintf(buffer, sizeof(buffer), "%02d:%02d:%02d GMT%c%02d%02d",
928 t.hour, t.minute, t.second,
929 gmtoffset(t) < 0 ? '-' : '+', offset / (60*60), (offset / 60) % 60);
930 }
931 }
932 return UString(buffer);
933}
934
935} // namespace JSC
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