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 * Copyright (C) 2010 &yet, LLC. (nate@andyet.net)
7 *
8 * The Original Code is Mozilla Communicator client code, released
9 * March 31, 1998.
10 *
11 * The Initial Developer of the Original Code is
12 * Netscape Communications Corporation.
13 * Portions created by the Initial Developer are Copyright (C) 1998
14 * the Initial Developer. All Rights Reserved.
15 *
16 * This library is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU Lesser General Public
18 * License as published by the Free Software Foundation; either
19 * version 2.1 of the License, or (at your option) any later version.
20 *
21 * This library is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 * Lesser General Public License for more details.
25 *
26 * You should have received a copy of the GNU Lesser General Public
27 * License along with this library; if not, write to the Free Software
28 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
29 *
30 * Alternatively, the contents of this file may be used under the terms
31 * of either the Mozilla Public License Version 1.1, found at
32 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
33 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
34 * (the "GPL"), in which case the provisions of the MPL or the GPL are
35 * applicable instead of those above. If you wish to allow use of your
36 * version of this file only under the terms of one of those two
37 * licenses (the MPL or the GPL) and not to allow others to use your
38 * version of this file under the LGPL, indicate your decision by
39 * deletingthe provisions above and replace them with the notice and
40 * other provisions required by the MPL or the GPL, as the case may be.
41 * If you do not delete the provisions above, a recipient may use your
42 * version of this file under any of the LGPL, the MPL or the GPL.
43
44 * Copyright 2006-2008 the V8 project authors. All rights reserved.
45 * Redistribution and use in source and binary forms, with or without
46 * modification, are permitted provided that the following conditions are
47 * met:
48 *
49 * * Redistributions of source code must retain the above copyright
50 * notice, this list of conditions and the following disclaimer.
51 * * Redistributions in binary form must reproduce the above
52 * copyright notice, this list of conditions and the following
53 * disclaimer in the documentation and/or other materials provided
54 * with the distribution.
55 * * Neither the name of Google Inc. nor the names of its
56 * contributors may be used to endorse or promote products derived
57 * from this software without specific prior written permission.
58 *
59 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
60 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
61 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
62 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
63 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
64 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
65 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
66 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
67 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
68 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
69 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
70 */
71
72 #include "config.h"
73 #include "DateMath.h"
74
75 #include "Assertions.h"
76 #include "ASCIICType.h"
77 #include "CurrentTime.h"
78 #include "MathExtras.h"
79 #include "StdLibExtras.h"
80 #include "StringExtras.h"
81
82 #include <algorithm>
83 #include <limits.h>
84 #include <limits>
85 #include <math.h>
86 #include <stdlib.h>
87 #include <time.h>
88 #include "wtf/text/StringBuilder.h"
89
90 #if OS(WIN)
91 #include <windows.h>
92 #endif
93
94 #if HAVE(SYS_TIME_H)
95 #include <sys/time.h>
96 #endif
97
98 using namespace WTF;
99
100 namespace WTF {
101
102 /* Constants */
103
104 static const double hoursPerDay = 24.0;
105 static const double secondsPerDay = 24.0 * 60.0 * 60.0;
106 static const double secondsPerHour = 60.0 * 60.0;
107
108 static const double maxUnixTime = 2145859200.0; // 12/31/2037
109
110 // Day of year for the first day of each month, where index 0 is January, and day 0 is January 1.
111 // First for non-leap years, then for leap years.
112 static const int firstDayOfMonth[2][12] = {
113 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
114 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
115 };
116
getLocalTime(const time_t * localTime,struct tm * localTM)117 static inline void getLocalTime(const time_t* localTime, struct tm* localTM)
118 {
119 #if COMPILER(MSVC)
120 localtime_s(localTM, localTime);
121 #else
122 localtime_r(localTime, localTM);
123 #endif
124 }
125
isLeapYear(int year)126 bool isLeapYear(int year)
127 {
128 if (year % 4 != 0)
129 return false;
130 if (year % 400 == 0)
131 return true;
132 if (year % 100 == 0)
133 return false;
134 return true;
135 }
136
daysInYear(int year)137 static inline int daysInYear(int year)
138 {
139 return 365 + isLeapYear(year);
140 }
141
daysFrom1970ToYear(int year)142 static inline double daysFrom1970ToYear(int year)
143 {
144 // The Gregorian Calendar rules for leap years:
145 // Every fourth year is a leap year. 2004, 2008, and 2012 are leap years.
146 // However, every hundredth year is not a leap year. 1900 and 2100 are not leap years.
147 // Every four hundred years, there's a leap year after all. 2000 and 2400 are leap years.
148
149 static const int leapDaysBefore1971By4Rule = 1970 / 4;
150 static const int excludedLeapDaysBefore1971By100Rule = 1970 / 100;
151 static const int leapDaysBefore1971By400Rule = 1970 / 400;
152
153 const double yearMinusOne = year - 1;
154 const double yearsToAddBy4Rule = floor(yearMinusOne / 4.0) - leapDaysBefore1971By4Rule;
155 const double yearsToExcludeBy100Rule = floor(yearMinusOne / 100.0) - excludedLeapDaysBefore1971By100Rule;
156 const double yearsToAddBy400Rule = floor(yearMinusOne / 400.0) - leapDaysBefore1971By400Rule;
157
158 return 365.0 * (year - 1970) + yearsToAddBy4Rule - yearsToExcludeBy100Rule + yearsToAddBy400Rule;
159 }
160
msToDays(double ms)161 static double msToDays(double ms)
162 {
163 return floor(ms / msPerDay);
164 }
165
twoDigitStringFromNumber(int number)166 static String twoDigitStringFromNumber(int number)
167 {
168 ASSERT(number >= 0 && number < 100);
169 if (number > 9)
170 return String::number(number);
171 return "0" + String::number(number);
172 }
173
msToYear(double ms)174 int msToYear(double ms)
175 {
176 int approxYear = static_cast<int>(floor(ms / (msPerDay * 365.2425)) + 1970);
177 double msFromApproxYearTo1970 = msPerDay * daysFrom1970ToYear(approxYear);
178 if (msFromApproxYearTo1970 > ms)
179 return approxYear - 1;
180 if (msFromApproxYearTo1970 + msPerDay * daysInYear(approxYear) <= ms)
181 return approxYear + 1;
182 return approxYear;
183 }
184
dayInYear(double ms,int year)185 int dayInYear(double ms, int year)
186 {
187 return static_cast<int>(msToDays(ms) - daysFrom1970ToYear(year));
188 }
189
msToMilliseconds(double ms)190 static inline double msToMilliseconds(double ms)
191 {
192 double result = fmod(ms, msPerDay);
193 if (result < 0)
194 result += msPerDay;
195 return result;
196 }
197
msToMinutes(double ms)198 static int msToMinutes(double ms)
199 {
200 double result = fmod(floor(ms / msPerMinute), minutesPerHour);
201 if (result < 0)
202 result += minutesPerHour;
203 return static_cast<int>(result);
204 }
205
msToHours(double ms)206 static int msToHours(double ms)
207 {
208 double result = fmod(floor(ms/msPerHour), hoursPerDay);
209 if (result < 0)
210 result += hoursPerDay;
211 return static_cast<int>(result);
212 }
213
monthFromDayInYear(int dayInYear,bool leapYear)214 int monthFromDayInYear(int dayInYear, bool leapYear)
215 {
216 const int d = dayInYear;
217 int step;
218
219 if (d < (step = 31))
220 return 0;
221 step += (leapYear ? 29 : 28);
222 if (d < step)
223 return 1;
224 if (d < (step += 31))
225 return 2;
226 if (d < (step += 30))
227 return 3;
228 if (d < (step += 31))
229 return 4;
230 if (d < (step += 30))
231 return 5;
232 if (d < (step += 31))
233 return 6;
234 if (d < (step += 31))
235 return 7;
236 if (d < (step += 30))
237 return 8;
238 if (d < (step += 31))
239 return 9;
240 if (d < (step += 30))
241 return 10;
242 return 11;
243 }
244
checkMonth(int dayInYear,int & startDayOfThisMonth,int & startDayOfNextMonth,int daysInThisMonth)245 static inline bool checkMonth(int dayInYear, int& startDayOfThisMonth, int& startDayOfNextMonth, int daysInThisMonth)
246 {
247 startDayOfThisMonth = startDayOfNextMonth;
248 startDayOfNextMonth += daysInThisMonth;
249 return (dayInYear <= startDayOfNextMonth);
250 }
251
dayInMonthFromDayInYear(int dayInYear,bool leapYear)252 int dayInMonthFromDayInYear(int dayInYear, bool leapYear)
253 {
254 const int d = dayInYear;
255 int step;
256 int next = 30;
257
258 if (d <= next)
259 return d + 1;
260 const int daysInFeb = (leapYear ? 29 : 28);
261 if (checkMonth(d, step, next, daysInFeb))
262 return d - step;
263 if (checkMonth(d, step, next, 31))
264 return d - step;
265 if (checkMonth(d, step, next, 30))
266 return d - step;
267 if (checkMonth(d, step, next, 31))
268 return d - step;
269 if (checkMonth(d, step, next, 30))
270 return d - step;
271 if (checkMonth(d, step, next, 31))
272 return d - step;
273 if (checkMonth(d, step, next, 31))
274 return d - step;
275 if (checkMonth(d, step, next, 30))
276 return d - step;
277 if (checkMonth(d, step, next, 31))
278 return d - step;
279 if (checkMonth(d, step, next, 30))
280 return d - step;
281 step = next;
282 return d - step;
283 }
284
dayInYear(int year,int month,int day)285 int dayInYear(int year, int month, int day)
286 {
287 return firstDayOfMonth[isLeapYear(year)][month] + day - 1;
288 }
289
dateToDaysFrom1970(int year,int month,int day)290 double dateToDaysFrom1970(int year, int month, int day)
291 {
292 year += month / 12;
293
294 month %= 12;
295 if (month < 0) {
296 month += 12;
297 --year;
298 }
299
300 double yearday = floor(daysFrom1970ToYear(year));
301 ASSERT((year >= 1970 && yearday >= 0) || (year < 1970 && yearday < 0));
302 return yearday + dayInYear(year, month, day);
303 }
304
305 // There is a hard limit at 2038 that we currently do not have a workaround
306 // for (rdar://problem/5052975).
maximumYearForDST()307 static inline int maximumYearForDST()
308 {
309 return 2037;
310 }
311
jsCurrentTime()312 static inline double jsCurrentTime()
313 {
314 // JavaScript doesn't recognize fractions of a millisecond.
315 return floor(WTF::currentTimeMS());
316 }
317
minimumYearForDST()318 static inline int minimumYearForDST()
319 {
320 // Because of the 2038 issue (see maximumYearForDST) if the current year is
321 // greater than the max year minus 27 (2010), we want to use the max year
322 // minus 27 instead, to ensure there is a range of 28 years that all years
323 // can map to.
324 return std::min(msToYear(jsCurrentTime()), maximumYearForDST() - 27) ;
325 }
326
327 /*
328 * Find an equivalent year for the one given, where equivalence is deterined by
329 * the two years having the same leapness and the first day of the year, falling
330 * on the same day of the week.
331 *
332 * This function returns a year between this current year and 2037, however this
333 * function will potentially return incorrect results if the current year is after
334 * 2010, (rdar://problem/5052975), if the year passed in is before 1900 or after
335 * 2100, (rdar://problem/5055038).
336 */
equivalentYearForDST(int year)337 static int equivalentYearForDST(int year)
338 {
339 // It is ok if the cached year is not the current year as long as the rules
340 // for DST did not change between the two years; if they did the app would need
341 // to be restarted.
342 static int minYear = minimumYearForDST();
343 int maxYear = maximumYearForDST();
344
345 int difference;
346 if (year > maxYear)
347 difference = minYear - year;
348 else if (year < minYear)
349 difference = maxYear - year;
350 else
351 return year;
352
353 int quotient = difference / 28;
354 int product = (quotient) * 28;
355
356 year += product;
357 ASSERT((year >= minYear && year <= maxYear) || (product - year == static_cast<int>(std::numeric_limits<double>::quiet_NaN())));
358 return year;
359 }
360
calculateUTCOffset()361 int32_t calculateUTCOffset()
362 {
363 #if OS(WIN)
364 TIME_ZONE_INFORMATION timeZoneInformation;
365 GetTimeZoneInformation(&timeZoneInformation);
366 int32_t bias = timeZoneInformation.Bias + timeZoneInformation.StandardBias;
367 return -bias * 60 * 1000;
368 #else
369 time_t localTime = time(0);
370 tm localt;
371 getLocalTime(&localTime, &localt);
372
373 // Get the difference between this time zone and UTC on the 1st of January of this year.
374 localt.tm_sec = 0;
375 localt.tm_min = 0;
376 localt.tm_hour = 0;
377 localt.tm_mday = 1;
378 localt.tm_mon = 0;
379 // Not setting localt.tm_year!
380 localt.tm_wday = 0;
381 localt.tm_yday = 0;
382 localt.tm_isdst = 0;
383 #if HAVE(TM_GMTOFF)
384 localt.tm_gmtoff = 0;
385 #endif
386 #if HAVE(TM_ZONE)
387 localt.tm_zone = 0;
388 #endif
389
390 #if HAVE(TIMEGM)
391 time_t utcOffset = timegm(&localt) - mktime(&localt);
392 #else
393 // Using a canned date of 01/01/2009 on platforms with weaker date-handling foo.
394 localt.tm_year = 109;
395 time_t utcOffset = 1230768000 - mktime(&localt);
396 #endif
397
398 return static_cast<int32_t>(utcOffset * 1000);
399 #endif
400 }
401
402 /*
403 * Get the DST offset for the time passed in.
404 */
calculateDSTOffsetSimple(double localTimeSeconds,double utcOffset)405 static double calculateDSTOffsetSimple(double localTimeSeconds, double utcOffset)
406 {
407 if (localTimeSeconds > maxUnixTime)
408 localTimeSeconds = maxUnixTime;
409 else if (localTimeSeconds < 0) // Go ahead a day to make localtime work (does not work with 0)
410 localTimeSeconds += secondsPerDay;
411
412 //input is UTC so we have to shift back to local time to determine DST thus the + getUTCOffset()
413 double offsetTime = (localTimeSeconds * msPerSecond) + utcOffset;
414
415 // Offset from UTC but doesn't include DST obviously
416 int offsetHour = msToHours(offsetTime);
417 int offsetMinute = msToMinutes(offsetTime);
418
419 // FIXME: time_t has a potential problem in 2038
420 time_t localTime = static_cast<time_t>(localTimeSeconds);
421
422 tm localTM;
423 getLocalTime(&localTime, &localTM);
424
425 double diff = ((localTM.tm_hour - offsetHour) * secondsPerHour) + ((localTM.tm_min - offsetMinute) * 60);
426
427 if (diff < 0)
428 diff += secondsPerDay;
429
430 return (diff * msPerSecond);
431 }
432
433 // Get the DST offset, given a time in UTC
calculateDSTOffset(double ms,double utcOffset)434 double calculateDSTOffset(double ms, double utcOffset)
435 {
436 // On Mac OS X, the call to localtime (see calculateDSTOffsetSimple) will return historically accurate
437 // DST information (e.g. New Zealand did not have DST from 1946 to 1974) however the JavaScript
438 // standard explicitly dictates that historical information should not be considered when
439 // determining DST. For this reason we shift away from years that localtime can handle but would
440 // return historically accurate information.
441 int year = msToYear(ms);
442 int equivalentYear = equivalentYearForDST(year);
443 if (year != equivalentYear) {
444 bool leapYear = isLeapYear(year);
445 int dayInYearLocal = dayInYear(ms, year);
446 int dayInMonth = dayInMonthFromDayInYear(dayInYearLocal, leapYear);
447 int month = monthFromDayInYear(dayInYearLocal, leapYear);
448 double day = dateToDaysFrom1970(equivalentYear, month, dayInMonth);
449 ms = (day * msPerDay) + msToMilliseconds(ms);
450 }
451
452 return calculateDSTOffsetSimple(ms / msPerSecond, utcOffset);
453 }
454
initializeDates()455 void initializeDates()
456 {
457 #if ASSERT_ENABLED
458 static bool alreadyInitialized;
459 ASSERT(!alreadyInitialized);
460 alreadyInitialized = true;
461 #endif
462
463 equivalentYearForDST(2000); // Need to call once to initialize a static used in this function.
464 }
465
ymdhmsToSeconds(int year,long mon,long day,long hour,long minute,double second)466 static inline double ymdhmsToSeconds(int year, long mon, long day, long hour, long minute, double second)
467 {
468 double days = (day - 32075)
469 + floor(1461 * (year + 4800.0 + (mon - 14) / 12) / 4)
470 + 367 * (mon - 2 - (mon - 14) / 12 * 12) / 12
471 - floor(3 * ((year + 4900.0 + (mon - 14) / 12) / 100) / 4)
472 - 2440588;
473 return ((days * hoursPerDay + hour) * minutesPerHour + minute) * secondsPerMinute + second;
474 }
475
476 // We follow the recommendation of RFC 2822 to consider all
477 // obsolete time zones not listed here equivalent to "-0000".
478 static const struct KnownZone {
479 #if !OS(WIN)
480 const
481 #endif
482 char tzName[4];
483 int tzOffset;
484 } known_zones[] = {
485 { "UT", 0 },
486 { "GMT", 0 },
487 { "EST", -300 },
488 { "EDT", -240 },
489 { "CST", -360 },
490 { "CDT", -300 },
491 { "MST", -420 },
492 { "MDT", -360 },
493 { "PST", -480 },
494 { "PDT", -420 }
495 };
496
skipSpacesAndComments(const char * & s)497 inline static void skipSpacesAndComments(const char*& s)
498 {
499 int nesting = 0;
500 char ch;
501 while ((ch = *s)) {
502 if (!isASCIISpace(ch)) {
503 if (ch == '(')
504 nesting++;
505 else if (ch == ')' && nesting > 0)
506 nesting--;
507 else if (nesting == 0)
508 break;
509 }
510 s++;
511 }
512 }
513
514 // returns 0-11 (Jan-Dec); -1 on failure
findMonth(const char * monthStr)515 static int findMonth(const char* monthStr)
516 {
517 ASSERT(monthStr);
518 char needle[4];
519 for (int i = 0; i < 3; ++i) {
520 if (!*monthStr)
521 return -1;
522 needle[i] = static_cast<char>(toASCIILower(*monthStr++));
523 }
524 needle[3] = '\0';
525 const char *haystack = "janfebmaraprmayjunjulaugsepoctnovdec";
526 const char *str = strstr(haystack, needle);
527 if (str) {
528 int position = static_cast<int>(str - haystack);
529 if (position % 3 == 0)
530 return position / 3;
531 }
532 return -1;
533 }
534
parseInt(const char * string,char ** stopPosition,int base,int * result)535 static bool parseInt(const char* string, char** stopPosition, int base, int* result)
536 {
537 long longResult = strtol(string, stopPosition, base);
538 // Avoid the use of errno as it is not available on Windows CE
539 if (string == *stopPosition || longResult <= std::numeric_limits<int>::min() || longResult >= std::numeric_limits<int>::max())
540 return false;
541 *result = static_cast<int>(longResult);
542 return true;
543 }
544
parseLong(const char * string,char ** stopPosition,int base,long * result)545 static bool parseLong(const char* string, char** stopPosition, int base, long* result)
546 {
547 *result = strtol(string, stopPosition, base);
548 // Avoid the use of errno as it is not available on Windows CE
549 if (string == *stopPosition || *result == std::numeric_limits<long>::min() || *result == std::numeric_limits<long>::max())
550 return false;
551 return true;
552 }
553
554 // Odd case where 'exec' is allowed to be 0, to accomodate a caller in WebCore.
parseDateFromNullTerminatedCharacters(const char * dateString,bool & haveTZ,int & offset)555 static double parseDateFromNullTerminatedCharacters(const char* dateString, bool& haveTZ, int& offset)
556 {
557 haveTZ = false;
558 offset = 0;
559
560 // This parses a date in the form:
561 // Tuesday, 09-Nov-99 23:12:40 GMT
562 // or
563 // Sat, 01-Jan-2000 08:00:00 GMT
564 // or
565 // Sat, 01 Jan 2000 08:00:00 GMT
566 // or
567 // 01 Jan 99 22:00 +0100 (exceptions in rfc822/rfc2822)
568 // ### non RFC formats, added for Javascript:
569 // [Wednesday] January 09 1999 23:12:40 GMT
570 // [Wednesday] January 09 23:12:40 GMT 1999
571 //
572 // We ignore the weekday.
573
574 // Skip leading space
575 skipSpacesAndComments(dateString);
576
577 long month = -1;
578 const char *wordStart = dateString;
579 // Check contents of first words if not number
580 while (*dateString && !isASCIIDigit(*dateString)) {
581 if (isASCIISpace(*dateString) || *dateString == '(') {
582 if (dateString - wordStart >= 3)
583 month = findMonth(wordStart);
584 skipSpacesAndComments(dateString);
585 wordStart = dateString;
586 } else
587 dateString++;
588 }
589
590 // Missing delimiter between month and day (like "January29")?
591 if (month == -1 && wordStart != dateString)
592 month = findMonth(wordStart);
593
594 skipSpacesAndComments(dateString);
595
596 if (!*dateString)
597 return std::numeric_limits<double>::quiet_NaN();
598
599 // ' 09-Nov-99 23:12:40 GMT'
600 char* newPosStr;
601 long day;
602 if (!parseLong(dateString, &newPosStr, 10, &day))
603 return std::numeric_limits<double>::quiet_NaN();
604 dateString = newPosStr;
605
606 if (!*dateString)
607 return std::numeric_limits<double>::quiet_NaN();
608
609 if (day < 0)
610 return std::numeric_limits<double>::quiet_NaN();
611
612 int year = 0;
613 if (day > 31) {
614 // ### where is the boundary and what happens below?
615 if (*dateString != '/')
616 return std::numeric_limits<double>::quiet_NaN();
617 // looks like a YYYY/MM/DD date
618 if (!*++dateString)
619 return std::numeric_limits<double>::quiet_NaN();
620 if (day <= std::numeric_limits<int>::min() || day >= std::numeric_limits<int>::max())
621 return std::numeric_limits<double>::quiet_NaN();
622 year = static_cast<int>(day);
623 if (!parseLong(dateString, &newPosStr, 10, &month))
624 return std::numeric_limits<double>::quiet_NaN();
625 month -= 1;
626 dateString = newPosStr;
627 if (*dateString++ != '/' || !*dateString)
628 return std::numeric_limits<double>::quiet_NaN();
629 if (!parseLong(dateString, &newPosStr, 10, &day))
630 return std::numeric_limits<double>::quiet_NaN();
631 dateString = newPosStr;
632 } else if (*dateString == '/' && month == -1) {
633 dateString++;
634 // This looks like a MM/DD/YYYY date, not an RFC date.
635 month = day - 1; // 0-based
636 if (!parseLong(dateString, &newPosStr, 10, &day))
637 return std::numeric_limits<double>::quiet_NaN();
638 if (day < 1 || day > 31)
639 return std::numeric_limits<double>::quiet_NaN();
640 dateString = newPosStr;
641 if (*dateString == '/')
642 dateString++;
643 if (!*dateString)
644 return std::numeric_limits<double>::quiet_NaN();
645 } else {
646 if (*dateString == '-')
647 dateString++;
648
649 skipSpacesAndComments(dateString);
650
651 if (*dateString == ',')
652 dateString++;
653
654 if (month == -1) { // not found yet
655 month = findMonth(dateString);
656 if (month == -1)
657 return std::numeric_limits<double>::quiet_NaN();
658
659 while (*dateString && *dateString != '-' && *dateString != ',' && !isASCIISpace(*dateString))
660 dateString++;
661
662 if (!*dateString)
663 return std::numeric_limits<double>::quiet_NaN();
664
665 // '-99 23:12:40 GMT'
666 if (*dateString != '-' && *dateString != '/' && *dateString != ',' && !isASCIISpace(*dateString))
667 return std::numeric_limits<double>::quiet_NaN();
668 dateString++;
669 }
670 }
671
672 if (month < 0 || month > 11)
673 return std::numeric_limits<double>::quiet_NaN();
674
675 // '99 23:12:40 GMT'
676 if (year <= 0 && *dateString) {
677 if (!parseInt(dateString, &newPosStr, 10, &year))
678 return std::numeric_limits<double>::quiet_NaN();
679 }
680
681 // Don't fail if the time is missing.
682 long hour = 0;
683 long minute = 0;
684 long second = 0;
685 if (!*newPosStr)
686 dateString = newPosStr;
687 else {
688 // ' 23:12:40 GMT'
689 if (!(isASCIISpace(*newPosStr) || *newPosStr == ',')) {
690 if (*newPosStr != ':')
691 return std::numeric_limits<double>::quiet_NaN();
692 // There was no year; the number was the hour.
693 year = -1;
694 } else {
695 // in the normal case (we parsed the year), advance to the next number
696 dateString = ++newPosStr;
697 skipSpacesAndComments(dateString);
698 }
699
700 parseLong(dateString, &newPosStr, 10, &hour);
701 // Do not check for errno here since we want to continue
702 // even if errno was set becasue we are still looking
703 // for the timezone!
704
705 // Read a number? If not, this might be a timezone name.
706 if (newPosStr != dateString) {
707 dateString = newPosStr;
708
709 if (hour < 0 || hour > 23)
710 return std::numeric_limits<double>::quiet_NaN();
711
712 if (!*dateString)
713 return std::numeric_limits<double>::quiet_NaN();
714
715 // ':12:40 GMT'
716 if (*dateString++ != ':')
717 return std::numeric_limits<double>::quiet_NaN();
718
719 if (!parseLong(dateString, &newPosStr, 10, &minute))
720 return std::numeric_limits<double>::quiet_NaN();
721 dateString = newPosStr;
722
723 if (minute < 0 || minute > 59)
724 return std::numeric_limits<double>::quiet_NaN();
725
726 // ':40 GMT'
727 if (*dateString && *dateString != ':' && !isASCIISpace(*dateString))
728 return std::numeric_limits<double>::quiet_NaN();
729
730 // seconds are optional in rfc822 + rfc2822
731 if (*dateString ==':') {
732 dateString++;
733
734 if (!parseLong(dateString, &newPosStr, 10, &second))
735 return std::numeric_limits<double>::quiet_NaN();
736 dateString = newPosStr;
737
738 if (second < 0 || second > 59)
739 return std::numeric_limits<double>::quiet_NaN();
740 }
741
742 skipSpacesAndComments(dateString);
743
744 if (strncasecmp(dateString, "AM", 2) == 0) {
745 if (hour > 12)
746 return std::numeric_limits<double>::quiet_NaN();
747 if (hour == 12)
748 hour = 0;
749 dateString += 2;
750 skipSpacesAndComments(dateString);
751 } else if (strncasecmp(dateString, "PM", 2) == 0) {
752 if (hour > 12)
753 return std::numeric_limits<double>::quiet_NaN();
754 if (hour != 12)
755 hour += 12;
756 dateString += 2;
757 skipSpacesAndComments(dateString);
758 }
759 }
760 }
761
762 // The year may be after the time but before the time zone.
763 if (isASCIIDigit(*dateString) && year == -1) {
764 if (!parseInt(dateString, &newPosStr, 10, &year))
765 return std::numeric_limits<double>::quiet_NaN();
766 dateString = newPosStr;
767 skipSpacesAndComments(dateString);
768 }
769
770 // Don't fail if the time zone is missing.
771 // Some websites omit the time zone (4275206).
772 if (*dateString) {
773 if (strncasecmp(dateString, "GMT", 3) == 0 || strncasecmp(dateString, "UTC", 3) == 0) {
774 dateString += 3;
775 haveTZ = true;
776 }
777
778 if (*dateString == '+' || *dateString == '-') {
779 int o;
780 if (!parseInt(dateString, &newPosStr, 10, &o))
781 return std::numeric_limits<double>::quiet_NaN();
782 dateString = newPosStr;
783
784 if (o < -9959 || o > 9959)
785 return std::numeric_limits<double>::quiet_NaN();
786
787 int sgn = (o < 0) ? -1 : 1;
788 o = abs(o);
789 if (*dateString != ':') {
790 if (o >= 24)
791 offset = ((o / 100) * 60 + (o % 100)) * sgn;
792 else
793 offset = o * 60 * sgn;
794 } else { // GMT+05:00
795 ++dateString; // skip the ':'
796 int o2;
797 if (!parseInt(dateString, &newPosStr, 10, &o2))
798 return std::numeric_limits<double>::quiet_NaN();
799 dateString = newPosStr;
800 offset = (o * 60 + o2) * sgn;
801 }
802 haveTZ = true;
803 } else {
804 for (size_t i = 0; i < WTF_ARRAY_LENGTH(known_zones); ++i) {
805 if (0 == strncasecmp(dateString, known_zones[i].tzName, strlen(known_zones[i].tzName))) {
806 offset = known_zones[i].tzOffset;
807 dateString += strlen(known_zones[i].tzName);
808 haveTZ = true;
809 break;
810 }
811 }
812 }
813 }
814
815 skipSpacesAndComments(dateString);
816
817 if (*dateString && year == -1) {
818 if (!parseInt(dateString, &newPosStr, 10, &year))
819 return std::numeric_limits<double>::quiet_NaN();
820 dateString = newPosStr;
821 skipSpacesAndComments(dateString);
822 }
823
824 // Trailing garbage
825 if (*dateString)
826 return std::numeric_limits<double>::quiet_NaN();
827
828 // Y2K: Handle 2 digit years.
829 if (year >= 0 && year < 100) {
830 if (year < 50)
831 year += 2000;
832 else
833 year += 1900;
834 }
835
836 return ymdhmsToSeconds(year, month + 1, day, hour, minute, second) * msPerSecond;
837 }
838
parseDateFromNullTerminatedCharacters(const char * dateString)839 double parseDateFromNullTerminatedCharacters(const char* dateString)
840 {
841 bool haveTZ;
842 int offset;
843 double ms = parseDateFromNullTerminatedCharacters(dateString, haveTZ, offset);
844 if (std::isnan(ms))
845 return std::numeric_limits<double>::quiet_NaN();
846
847 // fall back to local timezone
848 if (!haveTZ) {
849 double utcOffset = calculateUTCOffset();
850 double dstOffset = calculateDSTOffset(ms, utcOffset);
851 offset = (utcOffset + dstOffset) / msPerMinute;
852 }
853 return ms - (offset * msPerMinute);
854 }
855
856 // See http://tools.ietf.org/html/rfc2822#section-3.3 for more information.
makeRFC2822DateString(unsigned dayOfWeek,unsigned day,unsigned month,unsigned year,unsigned hours,unsigned minutes,unsigned seconds,int utcOffset)857 String makeRFC2822DateString(unsigned dayOfWeek, unsigned day, unsigned month, unsigned year, unsigned hours, unsigned minutes, unsigned seconds, int utcOffset)
858 {
859 StringBuilder stringBuilder;
860 stringBuilder.append(weekdayName[dayOfWeek]);
861 stringBuilder.appendLiteral(", ");
862 stringBuilder.appendNumber(day);
863 stringBuilder.append(' ');
864 stringBuilder.append(monthName[month]);
865 stringBuilder.append(' ');
866 stringBuilder.appendNumber(year);
867 stringBuilder.append(' ');
868
869 stringBuilder.append(twoDigitStringFromNumber(hours));
870 stringBuilder.append(':');
871 stringBuilder.append(twoDigitStringFromNumber(minutes));
872 stringBuilder.append(':');
873 stringBuilder.append(twoDigitStringFromNumber(seconds));
874 stringBuilder.append(' ');
875
876 stringBuilder.append(utcOffset > 0 ? '+' : '-');
877 int absoluteUTCOffset = abs(utcOffset);
878 stringBuilder.append(twoDigitStringFromNumber(absoluteUTCOffset / 60));
879 stringBuilder.append(twoDigitStringFromNumber(absoluteUTCOffset % 60));
880
881 return stringBuilder.toString();
882 }
883
884 } // namespace WTF
885