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webkit / WebKit / 611b5c715221d141f1aa004df01477ef3dbbd40f / . / Source / WTF / wtf / DateMath.cpp
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/*
* Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
* Copyright (C) 2006-2019 Apple Inc. All rights reserved.
* Copyright (C) 2009 Google Inc. All rights reserved.
* Copyright (C) 2007-2009 Torch Mobile, Inc.
* Copyright (C) 2010 &yet, LLC. (nate@andyet.net)
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Alternatively, the contents of this file may be used under the terms
* of either the Mozilla Public License Version 1.1, found at
* http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
* License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
* (the "GPL"), in which case the provisions of the MPL or the GPL are
* applicable instead of those above. If you wish to allow use of your
* version of this file only under the terms of one of those two
* licenses (the MPL or the GPL) and not to allow others to use your
* version of this file under the LGPL, indicate your decision by
* deletingthe provisions above and replace them with the notice and
* other provisions required by the MPL or the GPL, as the case may be.
* If you do not delete the provisions above, a recipient may use your
* version of this file under any of the LGPL, the MPL or the GPL.
* Copyright 2006-2008 the V8 project authors. All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include <wtf/DateMath.h>
#include <algorithm>
#include <limits>
#include <stdint.h>
#include <time.h>
#include <wtf/Assertions.h>
#include <wtf/ASCIICType.h>
#include <wtf/text/StringBuilder.h>
#if OS(WINDOWS)
#include <windows.h>
#endif
namespace WTF {
// FIXME: Should this function go into StringCommon.h or some other header?
template<unsigned length> inline bool startsWithLettersIgnoringASCIICase(const char* string, const char (&lowercaseLetters)[length])
{
return equalLettersIgnoringASCIICase(string, lowercaseLetters, length - 1);
}
/* Constants */
const char* const weekdayName[7] = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };
const char* const monthName[12] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
const char* const monthFullName[12] = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" };
// Day of year for the first day of each month, where index 0 is January, and day 0 is January 1.
// First for non-leap years, then for leap years.
const int firstDayOfMonth[2][12] = {
{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
};
#if !OS(WINDOWS) || HAVE(TM_GMTOFF)
static inline void getLocalTime(const time_t* localTime, struct tm* localTM)
{
#if HAVE(LOCALTIME_R)
localtime_r(localTime, localTM);
#else
localtime_s(localTime, localTM);
#endif
}
#endif
static void appendTwoDigitNumber(StringBuilder& builder, int number)
{
ASSERT(number >= 0);
ASSERT(number < 100);
builder.append(static_cast<LChar>('0' + number / 10));
builder.append(static_cast<LChar>('0' + number % 10));
}
static inline double msToMilliseconds(double ms)
{
double result = fmod(ms, msPerDay);
if (result < 0)
result += msPerDay;
return result;
}
// There is a hard limit at 2038 that we currently do not have a workaround
// for (rdar://problem/5052975).
static inline int maximumYearForDST()
{
return 2037;
}
static inline int minimumYearForDST()
{
// Because of the 2038 issue (see maximumYearForDST) if the current year is
// greater than the max year minus 27 (2010), we want to use the max year
// minus 27 instead, to ensure there is a range of 28 years that all years
// can map to.
return std::min(msToYear(jsCurrentTime()), maximumYearForDST() - 27) ;
}
/*
* Find an equivalent year for the one given, where equivalence is deterined by
* the two years having the same leapness and the first day of the year, falling
* on the same day of the week.
*
* This function returns a year between this current year and 2037, however this
* function will potentially return incorrect results if the current year is after
* 2010, (rdar://problem/5052975), if the year passed in is before 1900 or after
* 2100, (rdar://problem/5055038).
*/
int equivalentYearForDST(int year)
{
// It is ok if the cached year is not the current year as long as the rules
// for DST did not change between the two years; if they did the app would need
// to be restarted.
static int minYear = minimumYearForDST();
int maxYear = maximumYearForDST();
int difference;
if (year > maxYear)
difference = minYear - year;
else if (year < minYear)
difference = maxYear - year;
else
return year;
int quotient = difference / 28;
int product = (quotient) * 28;
year += product;
return year;
}
#if OS(WINDOWS)
typedef BOOL(WINAPI* callGetTimeZoneInformationForYear_t)(USHORT, PDYNAMIC_TIME_ZONE_INFORMATION, LPTIME_ZONE_INFORMATION);
static callGetTimeZoneInformationForYear_t timeZoneInformationForYearFunction()
{
static callGetTimeZoneInformationForYear_t getTimeZoneInformationForYear = nullptr;
if (getTimeZoneInformationForYear)
return getTimeZoneInformationForYear;
HMODULE module = ::GetModuleHandleW(L"kernel32.dll");
if (!module)
return nullptr;
getTimeZoneInformationForYear = reinterpret_cast<callGetTimeZoneInformationForYear_t>(::GetProcAddress(module, "GetTimeZoneInformationForYear"));
return getTimeZoneInformationForYear;
}
#endif
static int32_t calculateUTCOffset()
{
#if OS(WINDOWS)
TIME_ZONE_INFORMATION timeZoneInformation;
DWORD rc = 0;
if (callGetTimeZoneInformationForYear_t timeZoneFunction = timeZoneInformationForYearFunction()) {
// If available, use the Windows API call that takes into account the varying DST from
// year to year.
SYSTEMTIME systemTime;
::GetSystemTime(&systemTime);
rc = timeZoneFunction(systemTime.wYear, nullptr, &timeZoneInformation);
if (rc == TIME_ZONE_ID_INVALID)
return 0;
} else {
rc = ::GetTimeZoneInformation(&timeZoneInformation);
if (rc == TIME_ZONE_ID_INVALID)
return 0;
}
int32_t bias = timeZoneInformation.Bias;
if (rc == TIME_ZONE_ID_DAYLIGHT)
bias += timeZoneInformation.DaylightBias;
else if (rc == TIME_ZONE_ID_STANDARD || rc == TIME_ZONE_ID_UNKNOWN)
bias += timeZoneInformation.StandardBias;
return -bias * 60 * 1000;
#else
time_t localTime = time(0);
tm localt;
getLocalTime(&localTime, &localt);
// Get the difference between this time zone and UTC on the 1st of January of this year.
localt.tm_sec = 0;
localt.tm_min = 0;
localt.tm_hour = 0;
localt.tm_mday = 1;
localt.tm_mon = 0;
// Not setting localt.tm_year!
localt.tm_wday = 0;
localt.tm_yday = 0;
localt.tm_isdst = 0;
#if HAVE(TM_GMTOFF)
localt.tm_gmtoff = 0;
#endif
#if HAVE(TM_ZONE)
localt.tm_zone = 0;
#endif
#if HAVE(TIMEGM)
time_t utcOffset = timegm(&localt) - mktime(&localt);
#else
// Using a canned date of 01/01/2019 on platforms with weaker date-handling foo.
localt.tm_year = 119;
time_t utcOffset = 1546300800 - mktime(&localt);
#endif
return static_cast<int32_t>(utcOffset * 1000);
#endif
}
#if !HAVE(TM_GMTOFF)
#if OS(WINDOWS)
// Code taken from http://support.microsoft.com/kb/167296
static void UnixTimeToFileTime(time_t t, LPFILETIME pft)
{
// Note that LONGLONG is a 64-bit value
LONGLONG ll;
ll = Int32x32To64(t, 10000000) + 116444736000000000;
pft->dwLowDateTime = (DWORD)ll;
pft->dwHighDateTime = ll >> 32;
}
#endif
/*
* Get the DST offset for the time passed in.
*/
static double calculateDSTOffset(time_t localTime, double utcOffset)
{
// input is UTC so we have to shift back to local time to determine DST thus the + getUTCOffset()
double offsetTime = (localTime * msPerSecond) + utcOffset;
// Offset from UTC but doesn't include DST obviously
int offsetHour = msToHours(offsetTime);
int offsetMinute = msToMinutes(offsetTime);
#if OS(WINDOWS)
FILETIME utcFileTime;
UnixTimeToFileTime(localTime, &utcFileTime);
SYSTEMTIME utcSystemTime, localSystemTime;
if (!::FileTimeToSystemTime(&utcFileTime, &utcSystemTime))
return 0;
if (!::SystemTimeToTzSpecificLocalTime(nullptr, &utcSystemTime, &localSystemTime))
return 0;
double diff = ((localSystemTime.wHour - offsetHour) * secondsPerHour) + ((localSystemTime.wMinute - offsetMinute) * 60);
#else
tm localTM;
getLocalTime(&localTime, &localTM);
double diff = ((localTM.tm_hour - offsetHour) * secondsPerHour) + ((localTM.tm_min - offsetMinute) * 60);
#endif
if (diff < 0)
diff += secondsPerDay;
return (diff * msPerSecond);
}
#endif
// Returns combined offset in millisecond (UTC + DST).
LocalTimeOffset calculateLocalTimeOffset(double ms, TimeType inputTimeType)
{
#if HAVE(TM_GMTOFF)
double localToUTCTimeOffset = inputTimeType == LocalTime ? calculateUTCOffset() : 0;
#else
double localToUTCTimeOffset = calculateUTCOffset();
#endif
if (inputTimeType == LocalTime)
ms -= localToUTCTimeOffset;
// On Mac OS X, the call to localtime (see calculateDSTOffset) will return historically accurate
// DST information (e.g. New Zealand did not have DST from 1946 to 1974) however the JavaScript
// standard explicitly dictates that historical information should not be considered when
// determining DST. For this reason we shift away from years that localtime can handle but would
// return historically accurate information.
int year = msToYear(ms);
int equivalentYear = equivalentYearForDST(year);
if (year != equivalentYear) {
bool leapYear = isLeapYear(year);
int dayInYearLocal = dayInYear(ms, year);
int dayInMonth = dayInMonthFromDayInYear(dayInYearLocal, leapYear);
int month = monthFromDayInYear(dayInYearLocal, leapYear);
double day = dateToDaysFrom1970(equivalentYear, month, dayInMonth);
ms = (day * msPerDay) + msToMilliseconds(ms);
}
double localTimeSeconds = ms / msPerSecond;
if (localTimeSeconds > maxUnixTime)
localTimeSeconds = maxUnixTime;
else if (localTimeSeconds < 0) // Go ahead a day to make localtime work (does not work with 0).
localTimeSeconds += secondsPerDay;
// FIXME: time_t has a potential problem in 2038.
time_t localTime = static_cast<time_t>(localTimeSeconds);
#if HAVE(TM_GMTOFF)
tm localTM;
getLocalTime(&localTime, &localTM);
return LocalTimeOffset(localTM.tm_isdst, localTM.tm_gmtoff * msPerSecond);
#else
double dstOffset = calculateDSTOffset(localTime, localToUTCTimeOffset);
return LocalTimeOffset(dstOffset, localToUTCTimeOffset + dstOffset);
#endif
}
void initializeDates()
{
#if ASSERT_ENABLED
static bool alreadyInitialized;
ASSERT(!alreadyInitialized);
alreadyInitialized = true;
#endif
equivalentYearForDST(2000); // Need to call once to initialize a static used in this function.
}
static inline double ymdhmsToSeconds(int year, long mon, long day, long hour, long minute, double second)
{
int mday = firstDayOfMonth[isLeapYear(year)][mon - 1];
double ydays = daysFrom1970ToYear(year);
double dateSeconds = second + minute * secondsPerMinute + hour * secondsPerHour + (mday + day - 1 + ydays) * secondsPerDay;
// Clamp to EcmaScript standard (ecma262/#sec-time-values-and-time-range) of
// +/- 100,000,000 days from 01 January, 1970.
if (dateSeconds < -8640000000000.0 || dateSeconds > 8640000000000.0)
return std::numeric_limits<double>::quiet_NaN();
return dateSeconds;
}
// We follow the recommendation of RFC 2822 to consider all
// obsolete time zones not listed here equivalent to "-0000".
static const struct KnownZone {
#if !OS(WINDOWS)
const
#endif
char tzName[4];
int tzOffset;
} knownZones[] = {
{ "ut", 0 },
{ "gmt", 0 },
{ "est", -300 },
{ "edt", -240 },
{ "cst", -360 },
{ "cdt", -300 },
{ "mst", -420 },
{ "mdt", -360 },
{ "pst", -480 },
{ "pdt", -420 }
};
inline static void skipSpacesAndComments(const char*& s)
{
int nesting = 0;
char ch;
while ((ch = *s)) {
if (!isASCIISpace(ch)) {
if (ch == '(')
nesting++;
else if (ch == ')' && nesting > 0)
nesting--;
else if (nesting == 0)
break;
}
s++;
}
}
// returns 0-11 (Jan-Dec); -1 on failure
static int findMonth(const char* monthStr)
{
ASSERT(monthStr);
char needle[4];
for (int i = 0; i < 3; ++i) {
if (!*monthStr)
return -1;
needle[i] = static_cast<char>(toASCIILower(*monthStr++));
}
needle[3] = '\0';
const char *haystack = "janfebmaraprmayjunjulaugsepoctnovdec";
const char *str = strstr(haystack, needle);
if (str) {
int position = static_cast<int>(str - haystack);
if (position % 3 == 0)
return position / 3;
}
return -1;
}
static bool parseInt(const char* string, char** stopPosition, int base, int* result)
{
long longResult = strtol(string, stopPosition, base);
// Avoid the use of errno as it is not available on Windows CE
if (string == *stopPosition || longResult <= std::numeric_limits<int>::min() || longResult >= std::numeric_limits<int>::max())
return false;
*result = static_cast<int>(longResult);
return true;
}
static bool parseLong(const char* string, char** stopPosition, int base, long* result)
{
*result = strtol(string, stopPosition, base);
// Avoid the use of errno as it is not available on Windows CE
if (string == *stopPosition || *result == std::numeric_limits<long>::min() || *result == std::numeric_limits<long>::max())
return false;
return true;
}
// Parses a date with the format YYYY[-MM[-DD]].
// Year parsing is lenient, allows any number of digits, and +/-.
// Returns 0 if a parse error occurs, else returns the end of the parsed portion of the string.
static char* parseES5DatePortion(const char* currentPosition, int& year, long& month, long& day)
{
char* postParsePosition;
// This is a bit more lenient on the year string than ES5 specifies:
// instead of restricting to 4 digits (or 6 digits with mandatory +/-),
// it accepts any integer value. Consider this an implementation fallback.
if (!parseInt(currentPosition, &postParsePosition, 10, &year))
return nullptr;
// Check for presence of -MM portion.
if (*postParsePosition != '-')
return postParsePosition;
currentPosition = postParsePosition + 1;
if (!isASCIIDigit(*currentPosition))
return nullptr;
if (!parseLong(currentPosition, &postParsePosition, 10, &month))
return nullptr;
if ((postParsePosition - currentPosition) != 2)
return nullptr;
// Check for presence of -DD portion.
if (*postParsePosition != '-')
return postParsePosition;
currentPosition = postParsePosition + 1;
if (!isASCIIDigit(*currentPosition))
return nullptr;
if (!parseLong(currentPosition, &postParsePosition, 10, &day))
return nullptr;
if ((postParsePosition - currentPosition) != 2)
return nullptr;
return postParsePosition;
}
// Parses a time with the format HH:mm[:ss[.sss]][Z|(+|-)(00:00|0000|00)].
// Fractional seconds parsing is lenient, allows any number of digits.
// Returns 0 if a parse error occurs, else returns the end of the parsed portion of the string.
static char* parseES5TimePortion(char* currentPosition, long& hours, long& minutes, double& seconds, bool& isLocalTime, long& timeZoneSeconds)
{
isLocalTime = false;
char* postParsePosition;
if (!isASCIIDigit(*currentPosition))
return nullptr;
if (!parseLong(currentPosition, &postParsePosition, 10, &hours))
return nullptr;
if (*postParsePosition != ':' || (postParsePosition - currentPosition) != 2)
return nullptr;
currentPosition = postParsePosition + 1;
if (!isASCIIDigit(*currentPosition))
return nullptr;
if (!parseLong(currentPosition, &postParsePosition, 10, &minutes))
return nullptr;
if ((postParsePosition - currentPosition) != 2)
return nullptr;
currentPosition = postParsePosition;
// Seconds are optional.
if (*currentPosition == ':') {
++currentPosition;
long intSeconds;
if (!isASCIIDigit(*currentPosition))
return nullptr;
if (!parseLong(currentPosition, &postParsePosition, 10, &intSeconds))
return nullptr;
if ((postParsePosition - currentPosition) != 2)
return nullptr;
seconds = intSeconds;
if (*postParsePosition == '.') {
currentPosition = postParsePosition + 1;
// In ECMA-262-5 it's a bit unclear if '.' can be present without milliseconds, but
// a reasonable interpretation guided by the given examples and RFC 3339 says "no".
// We check the next character to avoid reading +/- timezone hours after an invalid decimal.
if (!isASCIIDigit(*currentPosition))
return nullptr;
// We are more lenient than ES5 by accepting more or less than 3 fraction digits.
long fracSeconds;
if (!parseLong(currentPosition, &postParsePosition, 10, &fracSeconds))
return nullptr;
long numFracDigits = postParsePosition - currentPosition;
seconds += fracSeconds * pow(10.0, static_cast<double>(-numFracDigits));
}
currentPosition = postParsePosition;
}
if (*currentPosition == 'Z')
return currentPosition + 1;
// Parse (+|-)(00:00|0000|00).
bool tzNegative;
if (*currentPosition == '-')
tzNegative = true;
else if (*currentPosition == '+')
tzNegative = false;
else {
isLocalTime = true;
return currentPosition;
}
++currentPosition;
long tzHours = 0;
long tzHoursAbs = 0;
long tzMinutes = 0;
if (!isASCIIDigit(*currentPosition))
return nullptr;
if (!parseLong(currentPosition, &postParsePosition, 10, &tzHours))
return nullptr;
if (*postParsePosition != ':') {
if ((postParsePosition - currentPosition) == 2) {
// "00" case.
tzHoursAbs = labs(tzHours);
} else if ((postParsePosition - currentPosition) == 4) {
// "0000" case.
tzHoursAbs = labs(tzHours);
tzMinutes = tzHoursAbs % 100;
tzHoursAbs = tzHoursAbs / 100;
} else
return nullptr;
} else {
// "00:00" case.
if ((postParsePosition - currentPosition) != 2)
return nullptr;
tzHoursAbs = labs(tzHours);
currentPosition = postParsePosition + 1; // Skip ":".
if (!isASCIIDigit(*currentPosition))
return nullptr;
if (!parseLong(currentPosition, &postParsePosition, 10, &tzMinutes))
return nullptr;
if ((postParsePosition - currentPosition) != 2)
return nullptr;
}
currentPosition = postParsePosition;
if (tzHoursAbs > 24)
return nullptr;
if (tzMinutes < 0 || tzMinutes > 59)
return nullptr;
timeZoneSeconds = 60 * (tzMinutes + (60 * tzHoursAbs));
if (tzNegative)
timeZoneSeconds = -timeZoneSeconds;
return currentPosition;
}
double parseES5DateFromNullTerminatedCharacters(const char* dateString, bool& isLocalTime)
{
isLocalTime = false;
// This parses a date of the form defined in ecma262/#sec-date-time-string-format
// (similar to RFC 3339 / ISO 8601: YYYY-MM-DDTHH:mm:ss[.sss]Z).
// In most cases it is intentionally strict (e.g. correct field widths, no stray whitespace).
static const long daysPerMonth[12] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
// The year must be present, but the other fields may be omitted - see ES5.1 15.9.1.15.
int year = 0;
long month = 1;
long day = 1;
long hours = 0;
long minutes = 0;
double seconds = 0;
long timeZoneSeconds = 0;
// Parse the date YYYY[-MM[-DD]]
char* currentPosition = parseES5DatePortion(dateString, year, month, day);
if (!currentPosition)
return std::numeric_limits<double>::quiet_NaN();
// Look for a time portion.
// Note: As of ES2016, when a UTC offset is missing, date-time forms are local time while date-only forms are UTC.
if (*currentPosition == 'T') {
// Parse the time HH:mm[:ss[.sss]][Z|(+|-)(00:00|0000|00)]
currentPosition = parseES5TimePortion(currentPosition + 1, hours, minutes, seconds, isLocalTime, timeZoneSeconds);
if (!currentPosition)
return std::numeric_limits<double>::quiet_NaN();
}
// Check that we have parsed all characters in the string.
if (*currentPosition)
return std::numeric_limits<double>::quiet_NaN();
// A few of these checks could be done inline above, but since many of them are interrelated
// we would be sacrificing readability to "optimize" the (presumably less common) failure path.
if (month < 1 || month > 12)
return std::numeric_limits<double>::quiet_NaN();
if (day < 1 || day > daysPerMonth[month - 1])
return std::numeric_limits<double>::quiet_NaN();
if (month == 2 && day > 28 && !isLeapYear(year))
return std::numeric_limits<double>::quiet_NaN();
if (hours < 0 || hours > 24)
return std::numeric_limits<double>::quiet_NaN();
if (hours == 24 && (minutes || seconds))
return std::numeric_limits<double>::quiet_NaN();
if (minutes < 0 || minutes > 59)
return std::numeric_limits<double>::quiet_NaN();
if (seconds < 0 || seconds >= 61)
return std::numeric_limits<double>::quiet_NaN();
if (seconds > 60) {
// Discard leap seconds by clamping to the end of a minute.
seconds = 60;
}
double dateSeconds = ymdhmsToSeconds(year, month, day, hours, minutes, seconds) - timeZoneSeconds;
return dateSeconds * msPerSecond;
}
// Odd case where 'exec' is allowed to be 0, to accomodate a caller in WebCore.
double parseDateFromNullTerminatedCharacters(const char* dateString, bool& isLocalTime)
{
isLocalTime = true;
int offset = 0;
// This parses a date in the form:
// Tuesday, 09-Nov-99 23:12:40 GMT
// or
// Sat, 01-Jan-2000 08:00:00 GMT
// or
// Sat, 01 Jan 2000 08:00:00 GMT
// or
// 01 Jan 99 22:00 +0100 (exceptions in rfc822/rfc2822)
// ### non RFC formats, added for Javascript:
// [Wednesday] January 09 1999 23:12:40 GMT
// [Wednesday] January 09 23:12:40 GMT 1999
//
// We ignore the weekday.
// Skip leading space
skipSpacesAndComments(dateString);
long month = -1;
const char *wordStart = dateString;
// Check contents of first words if not number
while (*dateString && !isASCIIDigit(*dateString)) {
if (isASCIISpace(*dateString) || *dateString == '(') {
if (dateString - wordStart >= 3)
month = findMonth(wordStart);
skipSpacesAndComments(dateString);
wordStart = dateString;
} else
dateString++;
}
// Missing delimiter between month and day (like "January29")?
if (month == -1 && wordStart != dateString)
month = findMonth(wordStart);
skipSpacesAndComments(dateString);
if (!*dateString)
return std::numeric_limits<double>::quiet_NaN();
// ' 09-Nov-99 23:12:40 GMT'
char* newPosStr;
long day;
if (!parseLong(dateString, &newPosStr, 10, &day))
return std::numeric_limits<double>::quiet_NaN();
dateString = newPosStr;
if (day < 0)
return std::numeric_limits<double>::quiet_NaN();
Optional<int> year;
if (day > 31) {
// ### where is the boundary and what happens below?
if (*dateString != '/')
return std::numeric_limits<double>::quiet_NaN();
// looks like a YYYY/MM/DD date
if (!*++dateString)
return std::numeric_limits<double>::quiet_NaN();
if (day <= std::numeric_limits<int>::min() || day >= std::numeric_limits<int>::max())
return std::numeric_limits<double>::quiet_NaN();
year = static_cast<int>(day);
if (!parseLong(dateString, &newPosStr, 10, &month))
return std::numeric_limits<double>::quiet_NaN();
month -= 1;
dateString = newPosStr;
if (*dateString++ != '/' || !*dateString)
return std::numeric_limits<double>::quiet_NaN();
if (!parseLong(dateString, &newPosStr, 10, &day))
return std::numeric_limits<double>::quiet_NaN();
dateString = newPosStr;
} else if (*dateString == '/' && month == -1) {
dateString++;
// This looks like a MM/DD/YYYY date, not an RFC date.
month = day - 1; // 0-based
if (!parseLong(dateString, &newPosStr, 10, &day))
return std::numeric_limits<double>::quiet_NaN();
if (day < 1 || day > 31)
return std::numeric_limits<double>::quiet_NaN();
dateString = newPosStr;
if (*dateString == '/')
dateString++;
if (!*dateString)
return std::numeric_limits<double>::quiet_NaN();
} else {
if (*dateString == '-')
dateString++;
skipSpacesAndComments(dateString);
if (*dateString == ',')
dateString++;
if (month == -1) { // not found yet
month = findMonth(dateString);
if (month == -1)
return std::numeric_limits<double>::quiet_NaN();
while (*dateString && *dateString != '-' && *dateString != ',' && !isASCIISpace(*dateString))
dateString++;
if (!*dateString)
return std::numeric_limits<double>::quiet_NaN();
// '-99 23:12:40 GMT'
if (*dateString != '-' && *dateString != '/' && *dateString != ',' && !isASCIISpace(*dateString))
return std::numeric_limits<double>::quiet_NaN();
dateString++;
}
}
if (month < 0 || month > 11)
return std::numeric_limits<double>::quiet_NaN();
// '99 23:12:40 GMT'
if (*dateString && !year) {
int result = 0;
if (!parseInt(dateString, &newPosStr, 10, &result))
return std::numeric_limits<double>::quiet_NaN();
year = result;
}
// Don't fail if the time is missing.
long hour = 0;
long minute = 0;
long second = 0;
if (!*newPosStr)
dateString = newPosStr;
else {
// ' 23:12:40 GMT'
if (!(isASCIISpace(*newPosStr) || *newPosStr == ',')) {
if (*newPosStr != ':')
return std::numeric_limits<double>::quiet_NaN();
// There was no year; the number was the hour.
year = WTF::nullopt;
} else {
// in the normal case (we parsed the year), advance to the next number
dateString = ++newPosStr;
skipSpacesAndComments(dateString);
}
parseLong(dateString, &newPosStr, 10, &hour);
// Do not check for errno here since we want to continue
// even if errno was set becasue we are still looking
// for the timezone!
// Read a number? If not, this might be a timezone name.
if (newPosStr != dateString) {
dateString = newPosStr;
if (hour < 0 || hour > 23)
return std::numeric_limits<double>::quiet_NaN();
if (!*dateString)
return std::numeric_limits<double>::quiet_NaN();
// ':12:40 GMT'
if (*dateString++ != ':')
return std::numeric_limits<double>::quiet_NaN();
if (!parseLong(dateString, &newPosStr, 10, &minute))
return std::numeric_limits<double>::quiet_NaN();
dateString = newPosStr;
if (minute < 0 || minute > 59)
return std::numeric_limits<double>::quiet_NaN();
// ':40 GMT'
if (*dateString && *dateString != ':' && !isASCIISpace(*dateString))
return std::numeric_limits<double>::quiet_NaN();
// seconds are optional in rfc822 + rfc2822
if (*dateString ==':') {
dateString++;
if (!parseLong(dateString, &newPosStr, 10, &second))
return std::numeric_limits<double>::quiet_NaN();
dateString = newPosStr;
if (second < 0 || second > 59)
return std::numeric_limits<double>::quiet_NaN();
}
skipSpacesAndComments(dateString);
if (startsWithLettersIgnoringASCIICase(dateString, "am")) {
if (hour > 12)
return std::numeric_limits<double>::quiet_NaN();
if (hour == 12)
hour = 0;
dateString += 2;
skipSpacesAndComments(dateString);
} else if (startsWithLettersIgnoringASCIICase(dateString, "pm")) {
if (hour > 12)
return std::numeric_limits<double>::quiet_NaN();
if (hour != 12)
hour += 12;
dateString += 2;
skipSpacesAndComments(dateString);
}
}
}
// The year may be after the time but before the time zone.
if (isASCIIDigit(*dateString) && !year) {
int result = 0;
if (!parseInt(dateString, &newPosStr, 10, &result))
return std::numeric_limits<double>::quiet_NaN();
year = result;
dateString = newPosStr;
skipSpacesAndComments(dateString);
}
// Don't fail if the time zone is missing.
// Some websites omit the time zone (4275206).
if (*dateString) {
if (startsWithLettersIgnoringASCIICase(dateString, "gmt") || startsWithLettersIgnoringASCIICase(dateString, "utc")) {
dateString += 3;
isLocalTime = false;
}
if (*dateString == '+' || *dateString == '-') {
int o;
if (!parseInt(dateString, &newPosStr, 10, &o))
return std::numeric_limits<double>::quiet_NaN();
dateString = newPosStr;
if (o < -9959 || o > 9959)
return std::numeric_limits<double>::quiet_NaN();
int sgn = (o < 0) ? -1 : 1;
o = abs(o);
if (*dateString != ':') {
if (o >= 24)
offset = ((o / 100) * 60 + (o % 100)) * sgn;
else
offset = o * 60 * sgn;
} else { // GMT+05:00
++dateString; // skip the ':'
int o2;
if (!parseInt(dateString, &newPosStr, 10, &o2))
return std::numeric_limits<double>::quiet_NaN();
dateString = newPosStr;
offset = (o * 60 + o2) * sgn;
}
isLocalTime = false;
} else {
for (auto& knownZone : knownZones) {
// Since the passed-in length is used for both strings, the following checks that
// dateString has the time zone name as a prefix, not that it is equal.
auto length = strlen(knownZone.tzName);
if (equalLettersIgnoringASCIICase(dateString, knownZone.tzName, length)) {
offset = knownZone.tzOffset;
dateString += length;
isLocalTime = false;
break;
}
}
}
}
skipSpacesAndComments(dateString);
if (*dateString && !year) {
int result = 0;
if (!parseInt(dateString, &newPosStr, 10, &result))
return std::numeric_limits<double>::quiet_NaN();
year = result;
dateString = newPosStr;
skipSpacesAndComments(dateString);
}
// Trailing garbage
if (*dateString)
return std::numeric_limits<double>::quiet_NaN();
// Y2K: Handle 2 digit years.
if (year) {
int yearValue = year.value();
if (yearValue >= 0 && yearValue < 100) {
if (yearValue < 50)
yearValue += 2000;
else
yearValue += 1900;
}
year = yearValue;
} else {
// We select 2000 as default value. This is because of the following reasons.
// 1. Year 2000 was used for the initial value of the variable `year`. While it won't be posed to users in WebKit,
// V8 used this 2000 as its default value. (As of April 2017, V8 is using the year 2001 and Spider Monkey is
// not doing this kind of fallback.)
// 2. It is a leap year. When using `new Date("Feb 29")`, we assume that people want to save month and day.
// Leap year can save user inputs if they is valid. If we use the current year instead, the current year
// may not be a leap year. In that case, `new Date("Feb 29").getMonth()` becomes 2 (March).
year = 2000;
}
ASSERT(year);
double dateSeconds = ymdhmsToSeconds(year.value(), month + 1, day, hour, minute, second) - offset * secondsPerMinute;
return dateSeconds * msPerSecond;
}
double parseDateFromNullTerminatedCharacters(const char* dateString)
{
bool isLocalTime;
double value = parseDateFromNullTerminatedCharacters(dateString, isLocalTime);
if (isLocalTime)
value -= calculateLocalTimeOffset(value, LocalTime).offset;
return value;
}
// See http://tools.ietf.org/html/rfc2822#section-3.3 for more information.
String makeRFC2822DateString(unsigned dayOfWeek, unsigned day, unsigned month, unsigned year, unsigned hours, unsigned minutes, unsigned seconds, int utcOffset)
{
StringBuilder stringBuilder;
stringBuilder.append(weekdayName[dayOfWeek], ", ", day, ' ', monthName[month], ' ', year, ' ');
appendTwoDigitNumber(stringBuilder, hours);
stringBuilder.append(':');
appendTwoDigitNumber(stringBuilder, minutes);
stringBuilder.append(':');
appendTwoDigitNumber(stringBuilder, seconds);
stringBuilder.append(' ');
stringBuilder.append(utcOffset > 0 ? '+' : '-');
int absoluteUTCOffset = abs(utcOffset);
appendTwoDigitNumber(stringBuilder, absoluteUTCOffset / 60);
appendTwoDigitNumber(stringBuilder, absoluteUTCOffset % 60);
return stringBuilder.toString();
}
} // namespace WTF