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 "StringExtras.h"
78
79#include <algorithm>
80#include <limits.h>
81#include <limits>
82#include <stdint.h>
83#include <time.h>
84
85
86#if HAVE(ERRNO_H)
87#include <errno.h>
88#endif
89
90#if OS(WINCE)
91extern "C" size_t strftime(char * const s, const size_t maxsize, const char * const format, const struct tm * const t);
92extern "C" struct tm * localtime(const time_t *timer);
93#endif
94
95#if HAVE(SYS_TIME_H)
96#include <sys/time.h>
97#endif
98
99#if HAVE(SYS_TIMEB_H)
100#include <sys/timeb.h>
101#endif
102
103#if USE(JSC)
104#include "CallFrame.h"
105#endif
106
107#include "MathExtras.h"
108
109#define NaN std::numeric_limits<double>::quiet_NaN()
110
111using namespace WTF;
112
113namespace WTF {
114
115/* Constants */
116
117static const double minutesPerDay = 24.0 * 60.0;
118static const double secondsPerDay = 24.0 * 60.0 * 60.0;
119static const double secondsPerYear = 24.0 * 60.0 * 60.0 * 365.0;
120
121static const double usecPerSec = 1000000.0;
122
123static const double maxUnixTime = 2145859200.0; // 12/31/2037
124// ECMAScript asks not to support for a date of which total
125// millisecond value is larger than the following value.
126// See 15.9.1.14 of ECMA-262 5th edition.
127static const double maxECMAScriptTime = 8.64E15;
128
129// Day of year for the first day of each month, where index 0 is January, and day 0 is January 1.
130// First for non-leap years, then for leap years.
131static const int firstDayOfMonth[2][12] = {
132 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
133 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
134};
135
136static inline bool isLeapYear(int year)
137{
138 if (year % 4 != 0)
139 return false;
140 if (year % 400 == 0)
141 return true;
142 if (year % 100 == 0)
143 return false;
144 return true;
145}
146
147static inline int daysInYear(int year)
148{
149 return 365 + isLeapYear(year);
150}
151
152static inline double daysFrom1970ToYear(int year)
153{
154 // The Gregorian Calendar rules for leap years:
155 // Every fourth year is a leap year. 2004, 2008, and 2012 are leap years.
156 // However, every hundredth year is not a leap year. 1900 and 2100 are not leap years.
157 // Every four hundred years, there's a leap year after all. 2000 and 2400 are leap years.
158
159 static const int leapDaysBefore1971By4Rule = 1970 / 4;
160 static const int excludedLeapDaysBefore1971By100Rule = 1970 / 100;
161 static const int leapDaysBefore1971By400Rule = 1970 / 400;
162
163 const double yearMinusOne = year - 1;
164 const double yearsToAddBy4Rule = floor(x: yearMinusOne / 4.0) - leapDaysBefore1971By4Rule;
165 const double yearsToExcludeBy100Rule = floor(x: yearMinusOne / 100.0) - excludedLeapDaysBefore1971By100Rule;
166 const double yearsToAddBy400Rule = floor(x: yearMinusOne / 400.0) - leapDaysBefore1971By400Rule;
167
168 return 365.0 * (year - 1970) + yearsToAddBy4Rule - yearsToExcludeBy100Rule + yearsToAddBy400Rule;
169}
170
171static inline double msToDays(double ms)
172{
173 return floor(x: ms / msPerDay);
174}
175
176int msToYear(double ms)
177{
178 int approxYear = static_cast<int>(floor(x: ms / (msPerDay * 365.2425)) + 1970);
179 double msFromApproxYearTo1970 = msPerDay * daysFrom1970ToYear(year: approxYear);
180 if (msFromApproxYearTo1970 > ms)
181 return approxYear - 1;
182 if (msFromApproxYearTo1970 + msPerDay * daysInYear(year: approxYear) <= ms)
183 return approxYear + 1;
184 return approxYear;
185}
186
187int dayInYear(double ms, int year)
188{
189 return static_cast<int>(msToDays(ms) - daysFrom1970ToYear(year));
190}
191
192static inline double msToMilliseconds(double ms)
193{
194 double result = fmod(x: ms, y: msPerDay);
195 if (result < 0)
196 result += msPerDay;
197 return result;
198}
199
200// 0: Sunday, 1: Monday, etc.
201static inline int msToWeekDay(double ms)
202{
203 int wd = (static_cast<int>(msToDays(ms)) + 4) % 7;
204 if (wd < 0)
205 wd += 7;
206 return wd;
207}
208
209static inline int msToSeconds(double ms)
210{
211 double result = fmod(x: floor(x: ms / msPerSecond), y: secondsPerMinute);
212 if (result < 0)
213 result += secondsPerMinute;
214 return static_cast<int>(result);
215}
216
217static inline int msToMinutes(double ms)
218{
219 double result = fmod(x: floor(x: ms / msPerMinute), y: minutesPerHour);
220 if (result < 0)
221 result += minutesPerHour;
222 return static_cast<int>(result);
223}
224
225static inline int msToHours(double ms)
226{
227 double result = fmod(x: floor(x: ms/msPerHour), y: hoursPerDay);
228 if (result < 0)
229 result += hoursPerDay;
230 return static_cast<int>(result);
231}
232
233int monthFromDayInYear(int dayInYear, bool leapYear)
234{
235 const int d = dayInYear;
236 int step;
237
238 if (d < (step = 31))
239 return 0;
240 step += (leapYear ? 29 : 28);
241 if (d < step)
242 return 1;
243 if (d < (step += 31))
244 return 2;
245 if (d < (step += 30))
246 return 3;
247 if (d < (step += 31))
248 return 4;
249 if (d < (step += 30))
250 return 5;
251 if (d < (step += 31))
252 return 6;
253 if (d < (step += 31))
254 return 7;
255 if (d < (step += 30))
256 return 8;
257 if (d < (step += 31))
258 return 9;
259 if (d < (step += 30))
260 return 10;
261 return 11;
262}
263
264static inline bool checkMonth(int dayInYear, int& startDayOfThisMonth, int& startDayOfNextMonth, int daysInThisMonth)
265{
266 startDayOfThisMonth = startDayOfNextMonth;
267 startDayOfNextMonth += daysInThisMonth;
268 return (dayInYear <= startDayOfNextMonth);
269}
270
271int dayInMonthFromDayInYear(int dayInYear, bool leapYear)
272{
273 const int d = dayInYear;
274 int step;
275 int next = 30;
276
277 if (d <= next)
278 return d + 1;
279 const int daysInFeb = (leapYear ? 29 : 28);
280 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: daysInFeb))
281 return d - step;
282 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: 31))
283 return d - step;
284 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: 30))
285 return d - step;
286 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: 31))
287 return d - step;
288 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: 30))
289 return d - step;
290 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: 31))
291 return d - step;
292 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: 31))
293 return d - step;
294 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: 30))
295 return d - step;
296 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: 31))
297 return d - step;
298 if (checkMonth(dayInYear: d, startDayOfThisMonth&: step, startDayOfNextMonth&: next, daysInThisMonth: 30))
299 return d - step;
300 step = next;
301 return d - step;
302}
303
304static inline int monthToDayInYear(int month, bool isLeapYear)
305{
306 return firstDayOfMonth[isLeapYear][month];
307}
308
309static inline double timeToMS(double hour, double min, double sec, double ms)
310{
311 return (((hour * minutesPerHour + min) * secondsPerMinute + sec) * msPerSecond + ms);
312}
313
314double dateToDaysFrom1970(int year, int month, int day)
315{
316 year += month / 12;
317
318 month %= 12;
319 if (month < 0) {
320 month += 12;
321 --year;
322 }
323
324 double yearday = floor(x: daysFrom1970ToYear(year));
325 ASSERT((year >= 1970 && yearday >= 0) || (year < 1970 && yearday < 0));
326 int monthday = monthToDayInYear(month, isLeapYear: isLeapYear(year));
327
328 return yearday + monthday + day - 1;
329}
330
331// There is a hard limit at 2038 that we currently do not have a workaround
332// for (rdar://problem/5052975).
333static inline int maximumYearForDST()
334{
335 return 2037;
336}
337
338static inline int minimumYearForDST()
339{
340 // Because of the 2038 issue (see maximumYearForDST) if the current year is
341 // greater than the max year minus 27 (2010), we want to use the max year
342 // minus 27 instead, to ensure there is a range of 28 years that all years
343 // can map to.
344 return std::min(a: msToYear(ms: jsCurrentTime()), b: maximumYearForDST() - 27) ;
345}
346
347/*
348 * Find an equivalent year for the one given, where equivalence is deterined by
349 * the two years having the same leapness and the first day of the year, falling
350 * on the same day of the week.
351 *
352 * This function returns a year between this current year and 2037, however this
353 * function will potentially return incorrect results if the current year is after
354 * 2010, (rdar://problem/5052975), if the year passed in is before 1900 or after
355 * 2100, (rdar://problem/5055038).
356 */
357int equivalentYearForDST(int year)
358{
359 // It is ok if the cached year is not the current year as long as the rules
360 // for DST did not change between the two years; if they did the app would need
361 // to be restarted.
362 static int minYear = minimumYearForDST();
363 int maxYear = maximumYearForDST();
364
365 int difference;
366 if (year > maxYear)
367 difference = minYear - year;
368 else if (year < minYear)
369 difference = maxYear - year;
370 else
371 return year;
372
373 int quotient = difference / 28;
374 int product = (quotient) * 28;
375
376 year += product;
377 ASSERT((year >= minYear && year <= maxYear) || (product - year == static_cast<int>(NaN)));
378 return year;
379}
380
381#if !HAVE(TM_GMTOFF)
382
383static int32_t calculateUTCOffset()
384{
385#if PLATFORM(BREWMP)
386 time_t localTime = static_cast<time_t>(currentTime());
387#else
388 time_t localTime = time(0);
389#endif
390 tm localt;
391 getLocalTime(&localTime, &localt);
392
393 // Get the difference between this time zone and UTC on the 1st of January of this year.
394 localt.tm_sec = 0;
395 localt.tm_min = 0;
396 localt.tm_hour = 0;
397 localt.tm_mday = 1;
398 localt.tm_mon = 0;
399 // Not setting localt.tm_year!
400 localt.tm_wday = 0;
401 localt.tm_yday = 0;
402 localt.tm_isdst = 0;
403#if HAVE(TM_GMTOFF)
404 localt.tm_gmtoff = 0;
405#endif
406#if HAVE(TM_ZONE)
407 localt.tm_zone = 0;
408#endif
409
410#if HAVE(TIMEGM)
411 time_t utcOffset = timegm(&localt) - mktime(&localt);
412#else
413 // Using a canned date of 01/01/2009 on platforms with weaker date-handling foo.
414 localt.tm_year = 109;
415 time_t utcOffset = 1230768000 - mktime(&localt);
416#endif
417
418 return static_cast<int32_t>(utcOffset * 1000);
419}
420
421/*
422 * Get the DST offset for the time passed in.
423 */
424static double calculateDSTOffset(time_t localTime, double utcOffset)
425{
426 //input is UTC so we have to shift back to local time to determine DST thus the + getUTCOffset()
427 double offsetTime = (localTime * msPerSecond) + utcOffset;
428
429 // Offset from UTC but doesn't include DST obviously
430 int offsetHour = msToHours(offsetTime);
431 int offsetMinute = msToMinutes(offsetTime);
432
433 tm localTM;
434 getLocalTime(&localTime, &localTM);
435
436 double diff = ((localTM.tm_hour - offsetHour) * secondsPerHour) + ((localTM.tm_min - offsetMinute) * 60);
437
438 if (diff < 0)
439 diff += secondsPerDay;
440
441 return (diff * msPerSecond);
442}
443
444#endif
445
446// Returns combined offset in millisecond (UTC + DST).
447LocalTimeOffset calculateLocalTimeOffset(double ms)
448{
449 // On Mac OS X, the call to localtime (see calculateDSTOffset) will return historically accurate
450 // DST information (e.g. New Zealand did not have DST from 1946 to 1974) however the JavaScript
451 // standard explicitly dictates that historical information should not be considered when
452 // determining DST. For this reason we shift away from years that localtime can handle but would
453 // return historically accurate information.
454 int year = msToYear(ms);
455 int equivalentYear = equivalentYearForDST(year);
456 if (year != equivalentYear) {
457 bool leapYear = isLeapYear(year);
458 int dayInYearLocal = dayInYear(ms, year);
459 int dayInMonth = dayInMonthFromDayInYear(dayInYear: dayInYearLocal, leapYear);
460 int month = monthFromDayInYear(dayInYear: dayInYearLocal, leapYear);
461 double day = dateToDaysFrom1970(year: equivalentYear, month, day: dayInMonth);
462 ms = (day * msPerDay) + msToMilliseconds(ms);
463 }
464
465 double localTimeSeconds = ms / msPerSecond;
466 if (localTimeSeconds > maxUnixTime)
467 localTimeSeconds = maxUnixTime;
468 else if (localTimeSeconds < 0) // Go ahead a day to make localtime work (does not work with 0).
469 localTimeSeconds += secondsPerDay;
470 // FIXME: time_t has a potential problem in 2038.
471 time_t localTime = static_cast<time_t>(localTimeSeconds);
472
473#if HAVE(TM_GMTOFF)
474 tm localTM;
475 getLocalTime(localTime: &localTime, localTM: &localTM);
476 return LocalTimeOffset(localTM.tm_isdst, localTM.tm_gmtoff * msPerSecond);
477#else
478 double utcOffset = calculateUTCOffset();
479 double dstOffset = calculateDSTOffset(localTime, utcOffset);
480 return LocalTimeOffset(dstOffset, utcOffset + dstOffset);
481#endif
482}
483
484void initializeDates()
485{
486#ifndef NDEBUG
487 static bool alreadyInitialized;
488 ASSERT(!alreadyInitialized);
489 alreadyInitialized = true;
490#endif
491
492 equivalentYearForDST(year: 2000); // Need to call once to initialize a static used in this function.
493}
494
495static inline double ymdhmsToSeconds(long year, int mon, int day, int hour, int minute, int second)
496{
497 double days = (day - 32075)
498 + floor(x: 1461 * (year + 4800.0 + (mon - 14) / 12) / 4)
499 + 367 * (mon - 2 - (mon - 14) / 12 * 12) / 12
500 - floor(x: 3 * ((year + 4900.0 + (mon - 14) / 12) / 100) / 4)
501 - 2440588;
502 return ((days * hoursPerDay + hour) * minutesPerHour + minute) * secondsPerMinute + second;
503}
504
505// We follow the recommendation of RFC 2822 to consider all
506// obsolete time zones not listed here equivalent to "-0000".
507static const struct KnownZone {
508#if !OS(WINDOWS)
509 const
510#endif
511 char tzName[4];
512 int tzOffset;
513} known_zones[] = {
514 { .tzName: "UT", .tzOffset: 0 },
515 { .tzName: "GMT", .tzOffset: 0 },
516 { .tzName: "EST", .tzOffset: -300 },
517 { .tzName: "EDT", .tzOffset: -240 },
518 { .tzName: "CST", .tzOffset: -360 },
519 { .tzName: "CDT", .tzOffset: -300 },
520 { .tzName: "MST", .tzOffset: -420 },
521 { .tzName: "MDT", .tzOffset: -360 },
522 { .tzName: "PST", .tzOffset: -480 },
523 { .tzName: "PDT", .tzOffset: -420 }
524};
525
526inline static void skipSpacesAndComments(const char*& s)
527{
528 int nesting = 0;
529 char ch;
530 while ((ch = *s)) {
531 if (!isASCIISpace(c: ch)) {
532 if (ch == '(')
533 nesting++;
534 else if (ch == ')' && nesting > 0)
535 nesting--;
536 else if (nesting == 0)
537 break;
538 }
539 s++;
540 }
541}
542
543// returns 0-11 (Jan-Dec); -1 on failure
544static int findMonth(const char* monthStr)
545{
546 ASSERT(monthStr);
547 char needle[4];
548 for (int i = 0; i < 3; ++i) {
549 if (!*monthStr)
550 return -1;
551 needle[i] = static_cast<char>(toASCIILower(c: *monthStr++));
552 }
553 needle[3] = '\0';
554 const char *haystack = "janfebmaraprmayjunjulaugsepoctnovdec";
555 const char *str = strstr(haystack: haystack, needle: needle);
556 if (str) {
557 int position = static_cast<int>(str - haystack);
558 if (position % 3 == 0)
559 return position / 3;
560 }
561 return -1;
562}
563
564static bool parseLong(const char* string, char** stopPosition, int base, long* result)
565{
566 *result = strtol(nptr: string, endptr: stopPosition, base: base);
567 // Avoid the use of errno as it is not available on Windows CE
568 if (string == *stopPosition || *result == LONG_MIN || *result == LONG_MAX)
569 return false;
570 return true;
571}
572
573// Odd case where 'exec' is allowed to be 0, to accomodate a caller in WebCore.
574static double parseDateFromNullTerminatedCharacters(const char* dateString, bool& haveTZ, int& offset)
575{
576 haveTZ = false;
577 offset = 0;
578
579 // This parses a date in the form:
580 // Tuesday, 09-Nov-99 23:12:40 GMT
581 // or
582 // Sat, 01-Jan-2000 08:00:00 GMT
583 // or
584 // Sat, 01 Jan 2000 08:00:00 GMT
585 // or
586 // 01 Jan 99 22:00 +0100 (exceptions in rfc822/rfc2822)
587 // ### non RFC formats, added for Javascript:
588 // [Wednesday] January 09 1999 23:12:40 GMT
589 // [Wednesday] January 09 23:12:40 GMT 1999
590 //
591 // We ignore the weekday.
592
593 // Skip leading space
594 skipSpacesAndComments(s&: dateString);
595
596 long month = -1;
597 const char *wordStart = dateString;
598 // Check contents of first words if not number
599 while (*dateString && !isASCIIDigit(c: *dateString)) {
600 if (isASCIISpace(c: *dateString) || *dateString == '(') {
601 if (dateString - wordStart >= 3)
602 month = findMonth(monthStr: wordStart);
603 skipSpacesAndComments(s&: dateString);
604 wordStart = dateString;
605 } else
606 dateString++;
607 }
608
609 // Missing delimiter between month and day (like "January29")?
610 if (month == -1 && wordStart != dateString)
611 month = findMonth(monthStr: wordStart);
612
613 skipSpacesAndComments(s&: dateString);
614
615 if (!*dateString)
616 return NaN;
617
618 // ' 09-Nov-99 23:12:40 GMT'
619 char* newPosStr;
620 long day;
621 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &day))
622 return NaN;
623 dateString = newPosStr;
624
625 if (!*dateString)
626 return NaN;
627
628 if (day < 0)
629 return NaN;
630
631 long year = 0;
632 if (day > 31) {
633 // ### where is the boundary and what happens below?
634 if (*dateString != '/')
635 return NaN;
636 // looks like a YYYY/MM/DD date
637 if (!*++dateString)
638 return NaN;
639 year = day;
640 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &month))
641 return NaN;
642 month -= 1;
643 dateString = newPosStr;
644 if (*dateString++ != '/' || !*dateString)
645 return NaN;
646 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &day))
647 return NaN;
648 dateString = newPosStr;
649 } else if (*dateString == '/' && month == -1) {
650 dateString++;
651 // This looks like a MM/DD/YYYY date, not an RFC date.
652 month = day - 1; // 0-based
653 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &day))
654 return NaN;
655 if (day < 1 || day > 31)
656 return NaN;
657 dateString = newPosStr;
658 if (*dateString == '/')
659 dateString++;
660 if (!*dateString)
661 return NaN;
662 } else {
663 if (*dateString == '-')
664 dateString++;
665
666 skipSpacesAndComments(s&: dateString);
667
668 if (*dateString == ',')
669 dateString++;
670
671 if (month == -1) { // not found yet
672 month = findMonth(monthStr: dateString);
673 if (month == -1)
674 return NaN;
675
676 while (*dateString && *dateString != '-' && *dateString != ',' && !isASCIISpace(c: *dateString))
677 dateString++;
678
679 if (!*dateString)
680 return NaN;
681
682 // '-99 23:12:40 GMT'
683 if (*dateString != '-' && *dateString != '/' && *dateString != ',' && !isASCIISpace(c: *dateString))
684 return NaN;
685 dateString++;
686 }
687 }
688
689 if (month < 0 || month > 11)
690 return NaN;
691
692 // '99 23:12:40 GMT'
693 if (year <= 0 && *dateString) {
694 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &year))
695 return NaN;
696 }
697
698 // Don't fail if the time is missing.
699 long hour = 0;
700 long minute = 0;
701 long second = 0;
702 if (!*newPosStr)
703 dateString = newPosStr;
704 else {
705 // ' 23:12:40 GMT'
706 if (!(isASCIISpace(c: *newPosStr) || *newPosStr == ',')) {
707 if (*newPosStr != ':')
708 return NaN;
709 // There was no year; the number was the hour.
710 year = -1;
711 } else {
712 // in the normal case (we parsed the year), advance to the next number
713 dateString = ++newPosStr;
714 skipSpacesAndComments(s&: dateString);
715 }
716
717 parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &hour);
718 // Do not check for errno here since we want to continue
719 // even if errno was set becasue we are still looking
720 // for the timezone!
721
722 // Read a number? If not, this might be a timezone name.
723 if (newPosStr != dateString) {
724 dateString = newPosStr;
725
726 if (hour < 0 || hour > 23)
727 return NaN;
728
729 if (!*dateString)
730 return NaN;
731
732 // ':12:40 GMT'
733 if (*dateString++ != ':')
734 return NaN;
735
736 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &minute))
737 return NaN;
738 dateString = newPosStr;
739
740 if (minute < 0 || minute > 59)
741 return NaN;
742
743 // ':40 GMT'
744 if (*dateString && *dateString != ':' && !isASCIISpace(c: *dateString))
745 return NaN;
746
747 // seconds are optional in rfc822 + rfc2822
748 if (*dateString ==':') {
749 dateString++;
750
751 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &second))
752 return NaN;
753 dateString = newPosStr;
754
755 if (second < 0 || second > 59)
756 return NaN;
757 }
758
759 skipSpacesAndComments(s&: dateString);
760
761 if (strncasecmp(s1: dateString, s2: "AM", n: 2) == 0) {
762 if (hour > 12)
763 return NaN;
764 if (hour == 12)
765 hour = 0;
766 dateString += 2;
767 skipSpacesAndComments(s&: dateString);
768 } else if (strncasecmp(s1: dateString, s2: "PM", n: 2) == 0) {
769 if (hour > 12)
770 return NaN;
771 if (hour != 12)
772 hour += 12;
773 dateString += 2;
774 skipSpacesAndComments(s&: dateString);
775 }
776 }
777 }
778
779 // Don't fail if the time zone is missing.
780 // Some websites omit the time zone (4275206).
781 if (*dateString) {
782 if (strncasecmp(s1: dateString, s2: "GMT", n: 3) == 0 || strncasecmp(s1: dateString, s2: "UTC", n: 3) == 0) {
783 dateString += 3;
784 haveTZ = true;
785 }
786
787 if (*dateString == '+' || *dateString == '-') {
788 long o;
789 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &o))
790 return NaN;
791 dateString = newPosStr;
792
793 if (o < -9959 || o > 9959)
794 return NaN;
795
796 int sgn = (o < 0) ? -1 : 1;
797 o = labs(x: o);
798 if (*dateString != ':') {
799 offset = ((o / 100) * 60 + (o % 100)) * sgn;
800 } else { // GMT+05:00
801 long o2;
802 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &o2))
803 return NaN;
804 dateString = newPosStr;
805 offset = (o * 60 + o2) * sgn;
806 }
807 haveTZ = true;
808 } else {
809 for (int i = 0; i < int(sizeof(known_zones) / sizeof(KnownZone)); i++) {
810 if (0 == strncasecmp(s1: dateString, s2: known_zones[i].tzName, n: strlen(s: known_zones[i].tzName))) {
811 offset = known_zones[i].tzOffset;
812 dateString += strlen(s: known_zones[i].tzName);
813 haveTZ = true;
814 break;
815 }
816 }
817 }
818 }
819
820 skipSpacesAndComments(s&: dateString);
821
822 if (*dateString && year == -1) {
823 if (!parseLong(string: dateString, stopPosition: &newPosStr, base: 10, result: &year))
824 return NaN;
825 dateString = newPosStr;
826 }
827
828 skipSpacesAndComments(s&: dateString);
829
830 // Trailing garbage
831 if (*dateString)
832 return NaN;
833
834 // Y2K: Handle 2 digit years.
835 if (year >= 0 && year < 100) {
836 if (year < 50)
837 year += 2000;
838 else
839 year += 1900;
840 }
841
842 return ymdhmsToSeconds(year, mon: month + 1, day, hour, minute, second) * msPerSecond;
843}
844
845double parseDateFromNullTerminatedCharacters(const char* dateString)
846{
847 bool haveTZ;
848 int offset;
849 double ms = parseDateFromNullTerminatedCharacters(dateString, haveTZ, offset);
850 if (std::isnan(x: ms))
851 return NaN;
852
853 // fall back to local timezone
854 if (!haveTZ)
855 offset = calculateLocalTimeOffset(ms).offset / msPerMinute;
856
857 return ms - (offset * msPerMinute);
858}
859
860double timeClip(double t)
861{
862 if (!std::isfinite(x: t))
863 return NaN;
864 if (fabs(x: t) > maxECMAScriptTime)
865 return NaN;
866 return trunc(x: t);
867}
868} // namespace WTF
869
870#if USE(JSC)
871namespace JSC {
872
873// Get the combined UTC + DST offset for the time passed in.
874//
875// NOTE: The implementation relies on the fact that no time zones have
876// more than one daylight savings offset change per month.
877// If this function is called with NaN it returns NaN.
878static LocalTimeOffset localTimeOffset(ExecState* exec, double ms)
879{
880 LocalTimeOffsetCache& cache = exec->globalData().localTimeOffsetCache;
881 double start = cache.start;
882 double end = cache.end;
883
884 if (start <= ms) {
885 // If the time fits in the cached interval, return the cached offset.
886 if (ms <= end) return cache.offset;
887
888 // Compute a possible new interval end.
889 double newEnd = end + cache.increment;
890
891 if (ms <= newEnd) {
892 LocalTimeOffset endOffset = calculateLocalTimeOffset(ms: newEnd);
893 if (cache.offset == endOffset) {
894 // If the offset at the end of the new interval still matches
895 // the offset in the cache, we grow the cached time interval
896 // and return the offset.
897 cache.end = newEnd;
898 cache.increment = msPerMonth;
899 return endOffset;
900 }
901 LocalTimeOffset offset = calculateLocalTimeOffset(ms);
902 if (offset == endOffset) {
903 // The offset at the given time is equal to the offset at the
904 // new end of the interval, so that means that we've just skipped
905 // the point in time where the DST offset change occurred. Updated
906 // the interval to reflect this and reset the increment.
907 cache.start = ms;
908 cache.end = newEnd;
909 cache.increment = msPerMonth;
910 } else {
911 // The interval contains a DST offset change and the given time is
912 // before it. Adjust the increment to avoid a linear search for
913 // the offset change point and change the end of the interval.
914 cache.increment /= 3;
915 cache.end = ms;
916 }
917 // Update the offset in the cache and return it.
918 cache.offset = offset;
919 return offset;
920 }
921 }
922
923 // Compute the DST offset for the time and shrink the cache interval
924 // to only contain the time. This allows fast repeated DST offset
925 // computations for the same time.
926 LocalTimeOffset offset = calculateLocalTimeOffset(ms);
927 cache.offset = offset;
928 cache.start = ms;
929 cache.end = ms;
930 cache.increment = msPerMonth;
931 return offset;
932}
933
934double gregorianDateTimeToMS(ExecState* exec, const GregorianDateTime& t, double milliSeconds, bool inputIsUTC)
935{
936 double day = dateToDaysFrom1970(year: t.year + 1900, month: t.month, day: t.monthDay);
937 double ms = timeToMS(hour: t.hour, min: t.minute, sec: t.second, ms: milliSeconds);
938 double result = (day * WTF::msPerDay) + ms;
939
940 if (!inputIsUTC)
941 result -= localTimeOffset(exec, ms: result).offset;
942
943 return result;
944}
945
946// input is UTC
947void msToGregorianDateTime(ExecState* exec, double ms, bool outputIsUTC, GregorianDateTime& tm)
948{
949 LocalTimeOffset localTime(false, 0);
950 if (!outputIsUTC) {
951 localTime = localTimeOffset(exec, ms);
952 ms += localTime.offset;
953 }
954
955 const int year = msToYear(ms);
956 tm.second = msToSeconds(ms);
957 tm.minute = msToMinutes(ms);
958 tm.hour = msToHours(ms);
959 tm.weekDay = msToWeekDay(ms);
960 tm.yearDay = dayInYear(ms, year);
961 tm.monthDay = dayInMonthFromDayInYear(dayInYear: tm.yearDay, leapYear: isLeapYear(year));
962 tm.month = monthFromDayInYear(dayInYear: tm.yearDay, leapYear: isLeapYear(year));
963 tm.year = year - 1900;
964 tm.isDST = localTime.isDST;
965 tm.utcOffset = localTime.offset / WTF::msPerSecond;
966 tm.timeZone = NULL;
967}
968
969double parseDateFromNullTerminatedCharacters(ExecState* exec, const char* dateString)
970{
971 ASSERT(exec);
972 bool haveTZ;
973 int offset;
974 double ms = WTF::parseDateFromNullTerminatedCharacters(dateString, haveTZ, offset);
975 if (std::isnan(x: ms))
976 return NaN;
977
978 // fall back to local timezone
979 if (!haveTZ)
980 offset = calculateLocalTimeOffset(ms).offset / msPerMinute;
981
982 return ms - (offset * WTF::msPerMinute);
983}
984
985} // namespace JSC
986#endif // USE(JSC)
987

source code of qtscript/src/3rdparty/javascriptcore/JavaScriptCore/wtf/DateMath.cpp