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Diffstat (limited to 'Source/JavaScriptCore/runtime/JSDateMath.cpp')
| -rw-r--r-- | Source/JavaScriptCore/runtime/JSDateMath.cpp | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/runtime/JSDateMath.cpp b/Source/JavaScriptCore/runtime/JSDateMath.cpp new file mode 100644 index 000000000..863073338 --- /dev/null +++ b/Source/JavaScriptCore/runtime/JSDateMath.cpp @@ -0,0 +1,267 @@ +/* + * Copyright (C) 1999-2000 Harri Porten (porten@kde.org) + * Copyright (C) 2006, 2007 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 "JSDateMath.h" + +#include "Assertions.h" +#include "ASCIICType.h" +#include "CurrentTime.h" +#include "JSObject.h" +#include "MathExtras.h" +#include "ScopeChain.h" +#include "StdLibExtras.h" +#include "StringExtras.h" + +#include <algorithm> +#include <limits.h> +#include <limits> +#include <stdint.h> +#include <time.h> +#include <wtf/text/StringBuilder.h> + +#if HAVE(ERRNO_H) +#include <errno.h> +#endif + +#if OS(WINCE) +extern "C" size_t strftime(char * const s, const size_t maxsize, const char * const format, const struct tm * const t); +extern "C" struct tm * localtime(const time_t *timer); +#endif + +#if HAVE(SYS_TIME_H) +#include <sys/time.h> +#endif + +#if HAVE(SYS_TIMEB_H) +#include <sys/timeb.h> +#endif + +using namespace WTF; + +namespace JSC { + +static inline double timeToMS(double hour, double min, double sec, double ms) +{ + return (((hour * minutesPerHour + min) * secondsPerMinute + sec) * msPerSecond + ms); +} + +static inline int msToSeconds(double ms) +{ + double result = fmod(floor(ms / msPerSecond), secondsPerMinute); + if (result < 0) + result += secondsPerMinute; + return static_cast<int>(result); +} + +// 0: Sunday, 1: Monday, etc. +static inline int msToWeekDay(double ms) +{ + int wd = (static_cast<int>(msToDays(ms)) + 4) % 7; + if (wd < 0) + wd += 7; + return wd; +} + +// Get the DST offset for the time passed in. +// +// NOTE: The implementation relies on the fact that no time zones have +// more than one daylight savings offset change per month. +// If this function is called with NaN it returns NaN. +static double getDSTOffset(ExecState* exec, double ms, double utcOffset) +{ + DSTOffsetCache& cache = exec->globalData().dstOffsetCache; + double start = cache.start; + double end = cache.end; + + if (start <= ms) { + // If the time fits in the cached interval, return the cached offset. + if (ms <= end) return cache.offset; + + // Compute a possible new interval end. + double newEnd = end + cache.increment; + + if (ms <= newEnd) { + double endOffset = calculateDSTOffset(newEnd, utcOffset); + if (cache.offset == endOffset) { + // If the offset at the end of the new interval still matches + // the offset in the cache, we grow the cached time interval + // and return the offset. + cache.end = newEnd; + cache.increment = msPerMonth; + return endOffset; + } else { + double offset = calculateDSTOffset(ms, utcOffset); + if (offset == endOffset) { + // The offset at the given time is equal to the offset at the + // new end of the interval, so that means that we've just skipped + // the point in time where the DST offset change occurred. Updated + // the interval to reflect this and reset the increment. + cache.start = ms; + cache.end = newEnd; + cache.increment = msPerMonth; + } else { + // The interval contains a DST offset change and the given time is + // before it. Adjust the increment to avoid a linear search for + // the offset change point and change the end of the interval. + cache.increment /= 3; + cache.end = ms; + } + // Update the offset in the cache and return it. + cache.offset = offset; + return offset; + } + } + } + + // Compute the DST offset for the time and shrink the cache interval + // to only contain the time. This allows fast repeated DST offset + // computations for the same time. + double offset = calculateDSTOffset(ms, utcOffset); + cache.offset = offset; + cache.start = ms; + cache.end = ms; + cache.increment = msPerMonth; + return offset; +} + +/* + * Get the difference in milliseconds between this time zone and UTC (GMT) + * NOT including DST. + */ +double getUTCOffset(ExecState* exec) +{ + double utcOffset = exec->globalData().cachedUTCOffset; + if (!isnan(utcOffset)) + return utcOffset; + exec->globalData().cachedUTCOffset = calculateUTCOffset(); + return exec->globalData().cachedUTCOffset; +} + +double gregorianDateTimeToMS(ExecState* exec, const GregorianDateTime& t, double milliSeconds, bool inputIsUTC) +{ + double day = dateToDaysFrom1970(t.year + 1900, t.month, t.monthDay); + double ms = timeToMS(t.hour, t.minute, t.second, milliSeconds); + double result = (day * WTF::msPerDay) + ms; + + if (!inputIsUTC) { // convert to UTC + double utcOffset = getUTCOffset(exec); + result -= utcOffset; + result -= getDSTOffset(exec, result, utcOffset); + } + + return result; +} + +// input is UTC +void msToGregorianDateTime(ExecState* exec, double ms, bool outputIsUTC, GregorianDateTime& tm) +{ + double dstOff = 0.0; + double utcOff = 0.0; + if (!outputIsUTC) { + utcOff = getUTCOffset(exec); + dstOff = getDSTOffset(exec, ms, utcOff); + ms += dstOff + utcOff; + } + + const int year = msToYear(ms); + tm.second = msToSeconds(ms); + tm.minute = msToMinutes(ms); + tm.hour = msToHours(ms); + tm.weekDay = msToWeekDay(ms); + tm.yearDay = dayInYear(ms, year); + tm.monthDay = dayInMonthFromDayInYear(tm.yearDay, isLeapYear(year)); + tm.month = monthFromDayInYear(tm.yearDay, isLeapYear(year)); + tm.year = year - 1900; + tm.isDST = dstOff != 0.0; + tm.utcOffset = static_cast<long>((dstOff + utcOff) / WTF::msPerSecond); + tm.timeZone = nullptr; +} + +double parseDateFromNullTerminatedCharacters(ExecState* exec, const char* dateString) +{ + ASSERT(exec); + bool haveTZ; + int offset; + double ms = WTF::parseDateFromNullTerminatedCharacters(dateString, haveTZ, offset); + if (isnan(ms)) + return std::numeric_limits<double>::quiet_NaN(); + + // fall back to local timezone + if (!haveTZ) { + double utcOffset = getUTCOffset(exec); + double dstOffset = getDSTOffset(exec, ms, utcOffset); + offset = static_cast<int>((utcOffset + dstOffset) / WTF::msPerMinute); + } + return ms - (offset * WTF::msPerMinute); +} + +} // namespace JSC |