Source/JavaScriptCore/runtime/JSDateMath.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
  * Copyright (C) 2006-2018 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 "JSObject.h"
 #include "JSScope.h"
 #include "JSCInlines.h"

 #include <algorithm>
 #include <limits.h>
 #include <limits>
 #include <stdint.h>
 #include <time.h>
 #include <wtf/ASCIICType.h>
 #include <wtf/Assertions.h>
 #include <wtf/MathExtras.h>
 #include <wtf/StdLibExtras.h>

 #if HAVE(ERRNO_H)
 #include <errno.h>
 #endif

 #if HAVE(SYS_TIME_H)
 #include <sys/time.h>
 #endif

 #if HAVE(SYS_TIMEB_H)
 #include <sys/timeb.h>
 #endif

 namespace JSC {

 // Get the combined UTC + 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 LocalTimeOffset localTimeOffset(VM& vm, double ms, WTF::TimeType inputTimeType = WTF::UTCTime)
 {
     LocalTimeOffsetCache& cache = inputTimeType == WTF::LocalTime
         ? vm.localTimeOffsetCache : vm.utcTimeOffsetCache;

     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) {
             LocalTimeOffset endOffset = calculateLocalTimeOffset(newEnd, inputTimeType);
             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 = WTF::msPerMonth;
                 return endOffset;
             }
             LocalTimeOffset offset = calculateLocalTimeOffset(ms, inputTimeType);
             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 = WTF::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.
     LocalTimeOffset offset = calculateLocalTimeOffset(ms, inputTimeType);
     cache.offset = offset;
     cache.start = ms;
     cache.end = ms;
     cache.increment = WTF::msPerMonth;
     return offset;
 }

 static inline double timeToMS(double hour, double min, double sec, double ms)
 {
     return (((hour * WTF::minutesPerHour + min) * WTF::secondsPerMinute + sec) * WTF::msPerSecond + ms);
 }

 double gregorianDateTimeToMS(VM& vm, const GregorianDateTime& t, double milliSeconds, WTF::TimeType inputTimeType)
 {
     double day = dateToDaysFrom1970(t.year(), t.month(), t.monthDay());
     double ms = timeToMS(t.hour(), t.minute(), t.second(), milliSeconds);
     double localTimeResult = (day * WTF::msPerDay) + ms;

     double localToUTCTimeOffset = inputTimeType == WTF::LocalTime
         ? localTimeOffset(vm, localTimeResult, inputTimeType).offset : 0;

     return localTimeResult - localToUTCTimeOffset;
 }

 // input is UTC
 void msToGregorianDateTime(VM& vm, double ms, WTF::TimeType outputTimeType, GregorianDateTime& tm)
 {
     LocalTimeOffset localTime;
     if (outputTimeType == WTF::LocalTime) {
         localTime = localTimeOffset(vm, ms);
         ms += localTime.offset;
     }
     tm = GregorianDateTime(ms, localTime);
 }

 static double parseDate(VM& vm, const char* dateString)
 {
     bool isLocalTime;
     double value = WTF::parseES5DateFromNullTerminatedCharacters(dateString, isLocalTime);
     if (std::isnan(value))
         value = WTF::parseDateFromNullTerminatedCharacters(dateString, isLocalTime);

     if (isLocalTime)
         value -= localTimeOffset(vm, value, WTF::LocalTime).offset;

     return value;
 }

 double parseDate(JSGlobalObject* globalObject, VM& vm, const String& date)
 {
     auto scope = DECLARE_THROW_SCOPE(vm);

     if (date == vm.cachedDateString)
         return vm.cachedDateStringValue;
     auto expectedString = date.tryGetUtf8();
     if (!expectedString) {
         if (expectedString.error() == UTF8ConversionError::OutOfMemory)
             throwOutOfMemoryError(globalObject, scope);
         // https://tc39.github.io/ecma262/#sec-date-objects section 20.3.3.2 states that:
         // "Unrecognizable Strings or dates containing illegal element values in the
         // format String shall cause Date.parse to return NaN."
         return std::numeric_limits<double>::quiet_NaN();
     }

     auto dateUtf8 = expectedString.value();
     double value = parseDate(vm, dateUtf8.data());
     vm.cachedDateString = date;
     vm.cachedDateStringValue = value;
     return value;
 }

 } // namespace JSC
	/*
	* Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
	* Copyright (C) 2006-2018 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 "JSObject.h"
	#include "JSScope.h"
	#include "JSCInlines.h"

	#include <algorithm>
	#include <limits.h>
	#include <limits>
	#include <stdint.h>
	#include <time.h>
	#include <wtf/ASCIICType.h>
	#include <wtf/Assertions.h>
	#include <wtf/MathExtras.h>
	#include <wtf/StdLibExtras.h>

	#if HAVE(ERRNO_H)
	#include <errno.h>
	#endif

	#if HAVE(SYS_TIME_H)
	#include <sys/time.h>
	#endif

	#if HAVE(SYS_TIMEB_H)
	#include <sys/timeb.h>
	#endif

	namespace JSC {

	// Get the combined UTC + 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 LocalTimeOffset localTimeOffset(VM& vm, double ms, WTF::TimeType inputTimeType = WTF::UTCTime)
	{
	LocalTimeOffsetCache& cache = inputTimeType == WTF::LocalTime
	? vm.localTimeOffsetCache : vm.utcTimeOffsetCache;

	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) {
	LocalTimeOffset endOffset = calculateLocalTimeOffset(newEnd, inputTimeType);
	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 = WTF::msPerMonth;
	return endOffset;
	}
	LocalTimeOffset offset = calculateLocalTimeOffset(ms, inputTimeType);
	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 = WTF::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.
	LocalTimeOffset offset = calculateLocalTimeOffset(ms, inputTimeType);
	cache.offset = offset;
	cache.start = ms;
	cache.end = ms;
	cache.increment = WTF::msPerMonth;
	return offset;
	}

	static inline double timeToMS(double hour, double min, double sec, double ms)
	{
	return (((hour * WTF::minutesPerHour + min) * WTF::secondsPerMinute + sec) * WTF::msPerSecond + ms);
	}

	double gregorianDateTimeToMS(VM& vm, const GregorianDateTime& t, double milliSeconds, WTF::TimeType inputTimeType)
	{
	double day = dateToDaysFrom1970(t.year(), t.month(), t.monthDay());
	double ms = timeToMS(t.hour(), t.minute(), t.second(), milliSeconds);
	double localTimeResult = (day * WTF::msPerDay) + ms;

	double localToUTCTimeOffset = inputTimeType == WTF::LocalTime
	? localTimeOffset(vm, localTimeResult, inputTimeType).offset : 0;

	return localTimeResult - localToUTCTimeOffset;
	}

	// input is UTC
	void msToGregorianDateTime(VM& vm, double ms, WTF::TimeType outputTimeType, GregorianDateTime& tm)
	{
	LocalTimeOffset localTime;
	if (outputTimeType == WTF::LocalTime) {
	localTime = localTimeOffset(vm, ms);
	ms += localTime.offset;
	}
	tm = GregorianDateTime(ms, localTime);
	}

	static double parseDate(VM& vm, const char* dateString)
	{
	bool isLocalTime;
	double value = WTF::parseES5DateFromNullTerminatedCharacters(dateString, isLocalTime);
	if (std::isnan(value))
	value = WTF::parseDateFromNullTerminatedCharacters(dateString, isLocalTime);

	if (isLocalTime)
	value -= localTimeOffset(vm, value, WTF::LocalTime).offset;

	return value;
	}

	double parseDate(JSGlobalObject* globalObject, VM& vm, const String& date)
	{
	auto scope = DECLARE_THROW_SCOPE(vm);

	if (date == vm.cachedDateString)
	return vm.cachedDateStringValue;
	auto expectedString = date.tryGetUtf8();
	if (!expectedString) {
	if (expectedString.error() == UTF8ConversionError::OutOfMemory)
	throwOutOfMemoryError(globalObject, scope);
	// https://tc39.github.io/ecma262/#sec-date-objects section 20.3.3.2 states that:
	// "Unrecognizable Strings or dates containing illegal element values in the
	// format String shall cause Date.parse to return NaN."
	return std::numeric_limits<double>::quiet_NaN();
	}

	auto dateUtf8 = expectedString.value();
	double value = parseDate(vm, dateUtf8.data());
	vm.cachedDateString = date;
	vm.cachedDateStringValue = value;
	return value;
	}

	} // namespace JSC