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
44 #include "config.h"
45 #include "DateMath.h"
46
47 #include "Assertions.h"
48 #include "ASCIICType.h"
49 #include "CurrentTime.h"
50 #include "MathExtras.h"
51 #include "StringExtras.h"
52
53 #include <algorithm>
54 #include <limits.h>
55 #include <limits>
56 #include <stdint.h>
57 #include <time.h>
58
59
60 #if HAVE(ERRNO_H)
61 #include <errno.h>
62 #endif
63
64 #if PLATFORM(DARWIN)
65 #include <notify.h>
66 #endif
67
68 #if PLATFORM(WINCE) && !PLATFORM(QT)
69 extern "C" size_t strftime(char * const s, const size_t maxsize, const char * const format, const struct tm * const t);
70 extern "C" struct tm * localtime(const time_t *timer);
71 #endif
72
73 #if HAVE(SYS_TIME_H)
74 #include <sys/time.h>
75 #endif
76
77 #if HAVE(SYS_TIMEB_H)
78 #include <sys/timeb.h>
79 #endif
80
81 #define NaN std::numeric_limits<double>::quiet_NaN()
82
83 namespace WTF {
84
85 /* Constants */
86
87 static const double minutesPerDay = 24.0 * 60.0;
88 static const double secondsPerDay = 24.0 * 60.0 * 60.0;
89 static const double secondsPerYear = 24.0 * 60.0 * 60.0 * 365.0;
90
91 static const double usecPerSec = 1000000.0;
92
93 static const double maxUnixTime = 2145859200.0; // 12/31/2037
94
95 // Day of year for the first day of each month, where index 0 is January, and day 0 is January 1.
96 // First for non-leap years, then for leap years.
97 static const int firstDayOfMonth[2][12] = {
98 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
99 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
100 };
101
isLeapYear(int year)102 static inline bool isLeapYear(int year)
103 {
104 if (year % 4 != 0)
105 return false;
106 if (year % 400 == 0)
107 return true;
108 if (year % 100 == 0)
109 return false;
110 return true;
111 }
112
daysInYear(int year)113 static inline int daysInYear(int year)
114 {
115 return 365 + isLeapYear(year);
116 }
117
daysFrom1970ToYear(int year)118 static inline double daysFrom1970ToYear(int year)
119 {
120 // The Gregorian Calendar rules for leap years:
121 // Every fourth year is a leap year. 2004, 2008, and 2012 are leap years.
122 // However, every hundredth year is not a leap year. 1900 and 2100 are not leap years.
123 // Every four hundred years, there's a leap year after all. 2000 and 2400 are leap years.
124
125 static const int leapDaysBefore1971By4Rule = 1970 / 4;
126 static const int excludedLeapDaysBefore1971By100Rule = 1970 / 100;
127 static const int leapDaysBefore1971By400Rule = 1970 / 400;
128
129 const double yearMinusOne = year - 1;
130 const double yearsToAddBy4Rule = floor(yearMinusOne / 4.0) - leapDaysBefore1971By4Rule;
131 const double yearsToExcludeBy100Rule = floor(yearMinusOne / 100.0) - excludedLeapDaysBefore1971By100Rule;
132 const double yearsToAddBy400Rule = floor(yearMinusOne / 400.0) - leapDaysBefore1971By400Rule;
133
134 return 365.0 * (year - 1970) + yearsToAddBy4Rule - yearsToExcludeBy100Rule + yearsToAddBy400Rule;
135 }
136
msToDays(double ms)137 static inline double msToDays(double ms)
138 {
139 return floor(ms / msPerDay);
140 }
141
msToYear(double ms)142 static inline int msToYear(double ms)
143 {
144 int approxYear = static_cast<int>(floor(ms / (msPerDay * 365.2425)) + 1970);
145 double msFromApproxYearTo1970 = msPerDay * daysFrom1970ToYear(approxYear);
146 if (msFromApproxYearTo1970 > ms)
147 return approxYear - 1;
148 if (msFromApproxYearTo1970 + msPerDay * daysInYear(approxYear) <= ms)
149 return approxYear + 1;
150 return approxYear;
151 }
152
dayInYear(double ms,int year)153 static inline int dayInYear(double ms, int year)
154 {
155 return static_cast<int>(msToDays(ms) - daysFrom1970ToYear(year));
156 }
157
msToMilliseconds(double ms)158 static inline double msToMilliseconds(double ms)
159 {
160 double result = fmod(ms, msPerDay);
161 if (result < 0)
162 result += msPerDay;
163 return result;
164 }
165
166 // 0: Sunday, 1: Monday, etc.
msToWeekDay(double ms)167 static inline int msToWeekDay(double ms)
168 {
169 int wd = (static_cast<int>(msToDays(ms)) + 4) % 7;
170 if (wd < 0)
171 wd += 7;
172 return wd;
173 }
174
msToSeconds(double ms)175 static inline int msToSeconds(double ms)
176 {
177 double result = fmod(floor(ms / msPerSecond), secondsPerMinute);
178 if (result < 0)
179 result += secondsPerMinute;
180 return static_cast<int>(result);
181 }
182
msToMinutes(double ms)183 static inline int msToMinutes(double ms)
184 {
185 double result = fmod(floor(ms / msPerMinute), minutesPerHour);
186 if (result < 0)
187 result += minutesPerHour;
188 return static_cast<int>(result);
189 }
190
msToHours(double ms)191 static inline int msToHours(double ms)
192 {
193 double result = fmod(floor(ms/msPerHour), hoursPerDay);
194 if (result < 0)
195 result += hoursPerDay;
196 return static_cast<int>(result);
197 }
198
monthFromDayInYear(int dayInYear,bool leapYear)199 static inline int monthFromDayInYear(int dayInYear, bool leapYear)
200 {
201 const int d = dayInYear;
202 int step;
203
204 if (d < (step = 31))
205 return 0;
206 step += (leapYear ? 29 : 28);
207 if (d < step)
208 return 1;
209 if (d < (step += 31))
210 return 2;
211 if (d < (step += 30))
212 return 3;
213 if (d < (step += 31))
214 return 4;
215 if (d < (step += 30))
216 return 5;
217 if (d < (step += 31))
218 return 6;
219 if (d < (step += 31))
220 return 7;
221 if (d < (step += 30))
222 return 8;
223 if (d < (step += 31))
224 return 9;
225 if (d < (step += 30))
226 return 10;
227 return 11;
228 }
229
checkMonth(int dayInYear,int & startDayOfThisMonth,int & startDayOfNextMonth,int daysInThisMonth)230 static inline bool checkMonth(int dayInYear, int& startDayOfThisMonth, int& startDayOfNextMonth, int daysInThisMonth)
231 {
232 startDayOfThisMonth = startDayOfNextMonth;
233 startDayOfNextMonth += daysInThisMonth;
234 return (dayInYear <= startDayOfNextMonth);
235 }
236
dayInMonthFromDayInYear(int dayInYear,bool leapYear)237 static inline int dayInMonthFromDayInYear(int dayInYear, bool leapYear)
238 {
239 const int d = dayInYear;
240 int step;
241 int next = 30;
242
243 if (d <= next)
244 return d + 1;
245 const int daysInFeb = (leapYear ? 29 : 28);
246 if (checkMonth(d, step, next, daysInFeb))
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 if (checkMonth(d, step, next, 31))
257 return d - step;
258 if (checkMonth(d, step, next, 31))
259 return d - step;
260 if (checkMonth(d, step, next, 30))
261 return d - step;
262 if (checkMonth(d, step, next, 31))
263 return d - step;
264 if (checkMonth(d, step, next, 30))
265 return d - step;
266 step = next;
267 return d - step;
268 }
269
monthToDayInYear(int month,bool isLeapYear)270 static inline int monthToDayInYear(int month, bool isLeapYear)
271 {
272 return firstDayOfMonth[isLeapYear][month];
273 }
274
timeToMS(double hour,double min,double sec,double ms)275 static inline double timeToMS(double hour, double min, double sec, double ms)
276 {
277 return (((hour * minutesPerHour + min) * secondsPerMinute + sec) * msPerSecond + ms);
278 }
279
dateToDayInYear(int year,int month,int day)280 static int dateToDayInYear(int year, int month, int day)
281 {
282 year += month / 12;
283
284 month %= 12;
285 if (month < 0) {
286 month += 12;
287 --year;
288 }
289
290 int yearday = static_cast<int>(floor(daysFrom1970ToYear(year)));
291 int monthday = monthToDayInYear(month, isLeapYear(year));
292
293 return yearday + monthday + day - 1;
294 }
295
getCurrentUTCTime()296 double getCurrentUTCTime()
297 {
298 return floor(getCurrentUTCTimeWithMicroseconds());
299 }
300
301 // Returns current time in milliseconds since 1 Jan 1970.
getCurrentUTCTimeWithMicroseconds()302 double getCurrentUTCTimeWithMicroseconds()
303 {
304 return currentTime() * 1000.0;
305 }
306
getLocalTime(const time_t * localTime,struct tm * localTM)307 void getLocalTime(const time_t* localTime, struct tm* localTM)
308 {
309 #if COMPILER(MSVC7) || COMPILER(MINGW) || PLATFORM(WINCE)
310 *localTM = *localtime(localTime);
311 #elif COMPILER(MSVC)
312 localtime_s(localTM, localTime);
313 #else
314 localtime_r(localTime, localTM);
315 #endif
316 }
317
318 // There is a hard limit at 2038 that we currently do not have a workaround
319 // for (rdar://problem/5052975).
maximumYearForDST()320 static inline int maximumYearForDST()
321 {
322 return 2037;
323 }
324
minimumYearForDST()325 static inline int minimumYearForDST()
326 {
327 // Because of the 2038 issue (see maximumYearForDST) if the current year is
328 // greater than the max year minus 27 (2010), we want to use the max year
329 // minus 27 instead, to ensure there is a range of 28 years that all years
330 // can map to.
331 return std::min(msToYear(getCurrentUTCTime()), maximumYearForDST() - 27) ;
332 }
333
334 /*
335 * Find an equivalent year for the one given, where equivalence is deterined by
336 * the two years having the same leapness and the first day of the year, falling
337 * on the same day of the week.
338 *
339 * This function returns a year between this current year and 2037, however this
340 * function will potentially return incorrect results if the current year is after
341 * 2010, (rdar://problem/5052975), if the year passed in is before 1900 or after
342 * 2100, (rdar://problem/5055038).
343 */
equivalentYearForDST(int year)344 int equivalentYearForDST(int year)
345 {
346 // It is ok if the cached year is not the current year as long as the rules
347 // for DST did not change between the two years; if they did the app would need
348 // to be restarted.
349 static int minYear = minimumYearForDST();
350 int maxYear = maximumYearForDST();
351
352 int difference;
353 if (year > maxYear)
354 difference = minYear - year;
355 else if (year < minYear)
356 difference = maxYear - year;
357 else
358 return year;
359
360 int quotient = difference / 28;
361 int product = (quotient) * 28;
362
363 year += product;
364 ASSERT((year >= minYear && year <= maxYear) || (product - year == static_cast<int>(NaN)));
365 return year;
366 }
367
calculateUTCOffset()368 static int32_t calculateUTCOffset()
369 {
370 time_t localTime = time(0);
371 tm localt;
372 getLocalTime(&localTime, &localt);
373
374 // Get the difference between this time zone and UTC on the 1st of January of this year.
375 localt.tm_sec = 0;
376 localt.tm_min = 0;
377 localt.tm_hour = 0;
378 localt.tm_mday = 1;
379 localt.tm_mon = 0;
380 // Not setting localt.tm_year!
381 localt.tm_wday = 0;
382 localt.tm_yday = 0;
383 localt.tm_isdst = 0;
384 #if HAVE(TM_GMTOFF)
385 localt.tm_gmtoff = 0;
386 #endif
387 #if HAVE(TM_ZONE)
388 localt.tm_zone = 0;
389 #endif
390
391 #if HAVE(TIMEGM)
392 time_t utcOffset = timegm(&localt) - mktime(&localt);
393 #else
394 // Using a canned date of 01/01/2009 on platforms with weaker date-handling foo.
395 localt.tm_year = 109;
396 time_t utcOffset = 1230768000 - mktime(&localt);
397 #endif
398
399 return static_cast<int32_t>(utcOffset * 1000);
400 }
401
402 #if PLATFORM(DARWIN)
403 static 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.
404 static bool s_haveCachedUTCOffset;
405 static int s_notificationToken;
406 #endif
407
408 /*
409 * Get the difference in milliseconds between this time zone and UTC (GMT)
410 * NOT including DST.
411 */
getUTCOffset()412 double getUTCOffset()
413 {
414 #if PLATFORM(DARWIN)
415 if (s_haveCachedUTCOffset) {
416 int notified;
417 uint32_t status = notify_check(s_notificationToken, ¬ified);
418 if (status == NOTIFY_STATUS_OK && !notified)
419 return s_cachedUTCOffset;
420 }
421 #endif
422
423 int32_t utcOffset = calculateUTCOffset();
424
425 #if PLATFORM(DARWIN)
426 // Theoretically, it is possible that several threads will be executing this code at once, in which case we will have a race condition,
427 // and a newer value may be overwritten. In practice, time zones don't change that often.
428 s_cachedUTCOffset = utcOffset;
429 #endif
430
431 return utcOffset;
432 }
433
434 /*
435 * Get the DST offset for the time passed in. Takes
436 * seconds (not milliseconds) and cannot handle dates before 1970
437 * on some OS'
438 */
getDSTOffsetSimple(double localTimeSeconds,double utcOffset)439 static double getDSTOffsetSimple(double localTimeSeconds, double utcOffset)
440 {
441 if (localTimeSeconds > maxUnixTime)
442 localTimeSeconds = maxUnixTime;
443 else if (localTimeSeconds < 0) // Go ahead a day to make localtime work (does not work with 0)
444 localTimeSeconds += secondsPerDay;
445
446 //input is UTC so we have to shift back to local time to determine DST thus the + getUTCOffset()
447 double offsetTime = (localTimeSeconds * msPerSecond) + utcOffset;
448
449 // Offset from UTC but doesn't include DST obviously
450 int offsetHour = msToHours(offsetTime);
451 int offsetMinute = msToMinutes(offsetTime);
452
453 // FIXME: time_t has a potential problem in 2038
454 time_t localTime = static_cast<time_t>(localTimeSeconds);
455
456 tm localTM;
457 getLocalTime(&localTime, &localTM);
458
459 double diff = ((localTM.tm_hour - offsetHour) * secondsPerHour) + ((localTM.tm_min - offsetMinute) * 60);
460
461 if (diff < 0)
462 diff += secondsPerDay;
463
464 return (diff * msPerSecond);
465 }
466
467 // Get the DST offset, given a time in UTC
getDSTOffset(double ms,double utcOffset)468 static double getDSTOffset(double ms, double utcOffset)
469 {
470 // On Mac OS X, the call to localtime (see getDSTOffsetSimple) will return historically accurate
471 // DST information (e.g. New Zealand did not have DST from 1946 to 1974) however the JavaScript
472 // standard explicitly dictates that historical information should not be considered when
473 // determining DST. For this reason we shift away from years that localtime can handle but would
474 // return historically accurate information.
475 int year = msToYear(ms);
476 int equivalentYear = equivalentYearForDST(year);
477 if (year != equivalentYear) {
478 bool leapYear = isLeapYear(year);
479 int dayInYearLocal = dayInYear(ms, year);
480 int dayInMonth = dayInMonthFromDayInYear(dayInYearLocal, leapYear);
481 int month = monthFromDayInYear(dayInYearLocal, leapYear);
482 int day = dateToDayInYear(equivalentYear, month, dayInMonth);
483 ms = (day * msPerDay) + msToMilliseconds(ms);
484 }
485
486 return getDSTOffsetSimple(ms / msPerSecond, utcOffset);
487 }
488
gregorianDateTimeToMS(const GregorianDateTime & t,double milliSeconds,bool inputIsUTC)489 double gregorianDateTimeToMS(const GregorianDateTime& t, double milliSeconds, bool inputIsUTC)
490 {
491 int day = dateToDayInYear(t.year + 1900, t.month, t.monthDay);
492 double ms = timeToMS(t.hour, t.minute, t.second, milliSeconds);
493 double result = (day * msPerDay) + ms;
494
495 if (!inputIsUTC) { // convert to UTC
496 double utcOffset = getUTCOffset();
497 result -= utcOffset;
498 result -= getDSTOffset(result, utcOffset);
499 }
500
501 return result;
502 }
503
msToGregorianDateTime(double ms,bool outputIsUTC,GregorianDateTime & tm)504 void msToGregorianDateTime(double ms, bool outputIsUTC, GregorianDateTime& tm)
505 {
506 // input is UTC
507 double dstOff = 0.0;
508 const double utcOff = getUTCOffset();
509
510 if (!outputIsUTC) { // convert to local time
511 dstOff = getDSTOffset(ms, utcOff);
512 ms += dstOff + utcOff;
513 }
514
515 const int year = msToYear(ms);
516 tm.second = msToSeconds(ms);
517 tm.minute = msToMinutes(ms);
518 tm.hour = msToHours(ms);
519 tm.weekDay = msToWeekDay(ms);
520 tm.yearDay = dayInYear(ms, year);
521 tm.monthDay = dayInMonthFromDayInYear(tm.yearDay, isLeapYear(year));
522 tm.month = monthFromDayInYear(tm.yearDay, isLeapYear(year));
523 tm.year = year - 1900;
524 tm.isDST = dstOff != 0.0;
525
526 tm.utcOffset = outputIsUTC ? 0 : static_cast<long>((dstOff + utcOff) / msPerSecond);
527 tm.timeZone = NULL;
528 }
529
initializeDates()530 void initializeDates()
531 {
532 #ifndef NDEBUG
533 static bool alreadyInitialized;
534 ASSERT(!alreadyInitialized++);
535 #endif
536
537 equivalentYearForDST(2000); // Need to call once to initialize a static used in this function.
538 #if PLATFORM(DARWIN)
539 // Register for a notification whenever the time zone changes.
540 uint32_t status = notify_register_check("com.apple.system.timezone", &s_notificationToken);
541 if (status == NOTIFY_STATUS_OK) {
542 s_cachedUTCOffset = calculateUTCOffset();
543 s_haveCachedUTCOffset = true;
544 }
545 #endif
546 }
547
ymdhmsToSeconds(long year,int mon,int day,int hour,int minute,int second)548 static inline double ymdhmsToSeconds(long year, int mon, int day, int hour, int minute, int second)
549 {
550 double days = (day - 32075)
551 + floor(1461 * (year + 4800.0 + (mon - 14) / 12) / 4)
552 + 367 * (mon - 2 - (mon - 14) / 12 * 12) / 12
553 - floor(3 * ((year + 4900.0 + (mon - 14) / 12) / 100) / 4)
554 - 2440588;
555 return ((days * hoursPerDay + hour) * minutesPerHour + minute) * secondsPerMinute + second;
556 }
557
558 // We follow the recommendation of RFC 2822 to consider all
559 // obsolete time zones not listed here equivalent to "-0000".
560 static const struct KnownZone {
561 #if !PLATFORM(WIN_OS)
562 const
563 #endif
564 char tzName[4];
565 int tzOffset;
566 } known_zones[] = {
567 { "UT", 0 },
568 { "GMT", 0 },
569 { "EST", -300 },
570 { "EDT", -240 },
571 { "CST", -360 },
572 { "CDT", -300 },
573 { "MST", -420 },
574 { "MDT", -360 },
575 { "PST", -480 },
576 { "PDT", -420 }
577 };
578
skipSpacesAndComments(const char * & s)579 inline static void skipSpacesAndComments(const char*& s)
580 {
581 int nesting = 0;
582 char ch;
583 while ((ch = *s)) {
584 if (!isASCIISpace(ch)) {
585 if (ch == '(')
586 nesting++;
587 else if (ch == ')' && nesting > 0)
588 nesting--;
589 else if (nesting == 0)
590 break;
591 }
592 s++;
593 }
594 }
595
596 // returns 0-11 (Jan-Dec); -1 on failure
findMonth(const char * monthStr)597 static int findMonth(const char* monthStr)
598 {
599 ASSERT(monthStr);
600 char needle[4];
601 for (int i = 0; i < 3; ++i) {
602 if (!*monthStr)
603 return -1;
604 needle[i] = static_cast<char>(toASCIILower(*monthStr++));
605 }
606 needle[3] = '\0';
607 const char *haystack = "janfebmaraprmayjunjulaugsepoctnovdec";
608 const char *str = strstr(haystack, needle);
609 if (str) {
610 int position = static_cast<int>(str - haystack);
611 if (position % 3 == 0)
612 return position / 3;
613 }
614 return -1;
615 }
616
parseLong(const char * string,char ** stopPosition,int base,long * result)617 static bool parseLong(const char* string, char** stopPosition, int base, long* result)
618 {
619 *result = strtol(string, stopPosition, base);
620 // Avoid the use of errno as it is not available on Windows CE
621 if (string == *stopPosition || *result == LONG_MIN || *result == LONG_MAX)
622 return false;
623 return true;
624 }
625
parseDateFromNullTerminatedCharacters(const char * dateString)626 double parseDateFromNullTerminatedCharacters(const char* dateString)
627 {
628 // This parses a date in the form:
629 // Tuesday, 09-Nov-99 23:12:40 GMT
630 // or
631 // Sat, 01-Jan-2000 08:00:00 GMT
632 // or
633 // Sat, 01 Jan 2000 08:00:00 GMT
634 // or
635 // 01 Jan 99 22:00 +0100 (exceptions in rfc822/rfc2822)
636 // ### non RFC formats, added for Javascript:
637 // [Wednesday] January 09 1999 23:12:40 GMT
638 // [Wednesday] January 09 23:12:40 GMT 1999
639 //
640 // We ignore the weekday.
641
642 // Skip leading space
643 skipSpacesAndComments(dateString);
644
645 long month = -1;
646 const char *wordStart = dateString;
647 // Check contents of first words if not number
648 while (*dateString && !isASCIIDigit(*dateString)) {
649 if (isASCIISpace(*dateString) || *dateString == '(') {
650 if (dateString - wordStart >= 3)
651 month = findMonth(wordStart);
652 skipSpacesAndComments(dateString);
653 wordStart = dateString;
654 } else
655 dateString++;
656 }
657
658 // Missing delimiter between month and day (like "January29")?
659 if (month == -1 && wordStart != dateString)
660 month = findMonth(wordStart);
661
662 skipSpacesAndComments(dateString);
663
664 if (!*dateString)
665 return NaN;
666
667 // ' 09-Nov-99 23:12:40 GMT'
668 char* newPosStr;
669 long day;
670 if (!parseLong(dateString, &newPosStr, 10, &day))
671 return NaN;
672 dateString = newPosStr;
673
674 if (!*dateString)
675 return NaN;
676
677 if (day < 0)
678 return NaN;
679
680 long year = 0;
681 if (day > 31) {
682 // ### where is the boundary and what happens below?
683 if (*dateString != '/')
684 return NaN;
685 // looks like a YYYY/MM/DD date
686 if (!*++dateString)
687 return NaN;
688 year = day;
689 if (!parseLong(dateString, &newPosStr, 10, &month))
690 return NaN;
691 month -= 1;
692 dateString = newPosStr;
693 if (*dateString++ != '/' || !*dateString)
694 return NaN;
695 if (!parseLong(dateString, &newPosStr, 10, &day))
696 return NaN;
697 dateString = newPosStr;
698 } else if (*dateString == '/' && month == -1) {
699 dateString++;
700 // This looks like a MM/DD/YYYY date, not an RFC date.
701 month = day - 1; // 0-based
702 if (!parseLong(dateString, &newPosStr, 10, &day))
703 return NaN;
704 if (day < 1 || day > 31)
705 return NaN;
706 dateString = newPosStr;
707 if (*dateString == '/')
708 dateString++;
709 if (!*dateString)
710 return NaN;
711 } else {
712 if (*dateString == '-')
713 dateString++;
714
715 skipSpacesAndComments(dateString);
716
717 if (*dateString == ',')
718 dateString++;
719
720 if (month == -1) { // not found yet
721 month = findMonth(dateString);
722 if (month == -1)
723 return NaN;
724
725 while (*dateString && *dateString != '-' && *dateString != ',' && !isASCIISpace(*dateString))
726 dateString++;
727
728 if (!*dateString)
729 return NaN;
730
731 // '-99 23:12:40 GMT'
732 if (*dateString != '-' && *dateString != '/' && *dateString != ',' && !isASCIISpace(*dateString))
733 return NaN;
734 dateString++;
735 }
736 }
737
738 if (month < 0 || month > 11)
739 return NaN;
740
741 // '99 23:12:40 GMT'
742 if (year <= 0 && *dateString) {
743 if (!parseLong(dateString, &newPosStr, 10, &year))
744 return NaN;
745 }
746
747 // Don't fail if the time is missing.
748 long hour = 0;
749 long minute = 0;
750 long second = 0;
751 if (!*newPosStr)
752 dateString = newPosStr;
753 else {
754 // ' 23:12:40 GMT'
755 if (!(isASCIISpace(*newPosStr) || *newPosStr == ',')) {
756 if (*newPosStr != ':')
757 return NaN;
758 // There was no year; the number was the hour.
759 year = -1;
760 } else {
761 // in the normal case (we parsed the year), advance to the next number
762 dateString = ++newPosStr;
763 skipSpacesAndComments(dateString);
764 }
765
766 parseLong(dateString, &newPosStr, 10, &hour);
767 // Do not check for errno here since we want to continue
768 // even if errno was set becasue we are still looking
769 // for the timezone!
770
771 // Read a number? If not, this might be a timezone name.
772 if (newPosStr != dateString) {
773 dateString = newPosStr;
774
775 if (hour < 0 || hour > 23)
776 return NaN;
777
778 if (!*dateString)
779 return NaN;
780
781 // ':12:40 GMT'
782 if (*dateString++ != ':')
783 return NaN;
784
785 if (!parseLong(dateString, &newPosStr, 10, &minute))
786 return NaN;
787 dateString = newPosStr;
788
789 if (minute < 0 || minute > 59)
790 return NaN;
791
792 // ':40 GMT'
793 if (*dateString && *dateString != ':' && !isASCIISpace(*dateString))
794 return NaN;
795
796 // seconds are optional in rfc822 + rfc2822
797 if (*dateString ==':') {
798 dateString++;
799
800 if (!parseLong(dateString, &newPosStr, 10, &second))
801 return NaN;
802 dateString = newPosStr;
803
804 if (second < 0 || second > 59)
805 return NaN;
806 }
807
808 skipSpacesAndComments(dateString);
809
810 if (strncasecmp(dateString, "AM", 2) == 0) {
811 if (hour > 12)
812 return NaN;
813 if (hour == 12)
814 hour = 0;
815 dateString += 2;
816 skipSpacesAndComments(dateString);
817 } else if (strncasecmp(dateString, "PM", 2) == 0) {
818 if (hour > 12)
819 return NaN;
820 if (hour != 12)
821 hour += 12;
822 dateString += 2;
823 skipSpacesAndComments(dateString);
824 }
825 }
826 }
827
828 bool haveTZ = false;
829 int offset = 0;
830
831 // Don't fail if the time zone is missing.
832 // Some websites omit the time zone (4275206).
833 if (*dateString) {
834 if (strncasecmp(dateString, "GMT", 3) == 0 || strncasecmp(dateString, "UTC", 3) == 0) {
835 dateString += 3;
836 haveTZ = true;
837 }
838
839 if (*dateString == '+' || *dateString == '-') {
840 long o;
841 if (!parseLong(dateString, &newPosStr, 10, &o))
842 return NaN;
843 dateString = newPosStr;
844
845 if (o < -9959 || o > 9959)
846 return NaN;
847
848 int sgn = (o < 0) ? -1 : 1;
849 o = labs(o);
850 if (*dateString != ':') {
851 offset = ((o / 100) * 60 + (o % 100)) * sgn;
852 } else { // GMT+05:00
853 long o2;
854 if (!parseLong(dateString, &newPosStr, 10, &o2))
855 return NaN;
856 dateString = newPosStr;
857 offset = (o * 60 + o2) * sgn;
858 }
859 haveTZ = true;
860 } else {
861 for (int i = 0; i < int(sizeof(known_zones) / sizeof(KnownZone)); i++) {
862 if (0 == strncasecmp(dateString, known_zones[i].tzName, strlen(known_zones[i].tzName))) {
863 offset = known_zones[i].tzOffset;
864 dateString += strlen(known_zones[i].tzName);
865 haveTZ = true;
866 break;
867 }
868 }
869 }
870 }
871
872 skipSpacesAndComments(dateString);
873
874 if (*dateString && year == -1) {
875 if (!parseLong(dateString, &newPosStr, 10, &year))
876 return NaN;
877 dateString = newPosStr;
878 }
879
880 skipSpacesAndComments(dateString);
881
882 // Trailing garbage
883 if (*dateString)
884 return NaN;
885
886 // Y2K: Handle 2 digit years.
887 if (year >= 0 && year < 100) {
888 if (year < 50)
889 year += 2000;
890 else
891 year += 1900;
892 }
893
894 // fall back to local timezone
895 if (!haveTZ) {
896 GregorianDateTime t;
897 t.monthDay = day;
898 t.month = month;
899 t.year = year - 1900;
900 t.isDST = -1;
901 t.second = second;
902 t.minute = minute;
903 t.hour = hour;
904
905 // Use our gregorianDateTimeToMS() rather than mktime() as the latter can't handle the full year range.
906 return gregorianDateTimeToMS(t, 0, false);
907 }
908
909 return (ymdhmsToSeconds(year, month + 1, day, hour, minute, second) - (offset * 60.0)) * msPerSecond;
910 }
911
timeClip(double t)912 double timeClip(double t)
913 {
914 if (!isfinite(t))
915 return NaN;
916 if (fabs(t) > 8.64E15)
917 return NaN;
918 return trunc(t);
919 }
920
921
922 } // namespace WTF
923