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/*
* Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
* Copyright (C) 2006-2024 Apple Inc. All rights reserved.
* Copyright (C) 2009 Google Inc. All rights reserved.
* Copyright (C) 2012 the V8 project authors. All rights reserved.
* Copyright (C) 2010 Research In Motion Limited. All rights reserved.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* 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.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
*/
#pragma once
#include "DateInstanceCache.h"
#include <wtf/DateMath.h>
#include <wtf/GregorianDateTime.h>
#include <wtf/SaturatedArithmetic.h>
#include <wtf/TZoneMalloc.h>
WTF_ALLOW_UNSAFE_BUFFER_USAGE_BEGIN
namespace JSC {
class JSGlobalObject;
class OpaqueICUTimeZone;
class VM;
static constexpr double minECMAScriptTime = -8.64E15;
#if PLATFORM(COCOA)
extern JS_EXPORT_PRIVATE std::atomic<uint64_t> lastTimeZoneID;
#endif
// We do not expose icu::TimeZone in this header file. And we cannot use icu::TimeZone forward declaration
// because icu namespace can be an alias to icu$verNum namespace.
struct OpaqueICUTimeZoneDeleter {
JS_EXPORT_PRIVATE void operator()(OpaqueICUTimeZone*);
};
struct LocalTimeOffsetCache {
LocalTimeOffsetCache() = default;
bool isEmpty() { return start > end; }
LocalTimeOffset offset { };
int64_t start { WTF::Int64Milliseconds::maxECMAScriptTime };
int64_t end { WTF::Int64Milliseconds::minECMAScriptTime };
uint64_t epoch { 0 };
};
class DateCache {
WTF_MAKE_TZONE_NON_HEAP_ALLOCATABLE(DateCache);
WTF_MAKE_NONCOPYABLE(DateCache);
public:
DateCache();
~DateCache();
bool hasTimeZoneChange()
{
#if PLATFORM(COCOA)
return m_cachedTimezoneID != lastTimeZoneID;
#else
return true; // always force a time zone check.
#endif
}
void resetIfNecessary()
{
#if PLATFORM(COCOA)
if (LIKELY(!hasTimeZoneChange()))
return;
m_cachedTimezoneID = lastTimeZoneID;
#endif
resetIfNecessarySlow();
}
JS_EXPORT_PRIVATE void resetIfNecessarySlow();
String defaultTimeZone();
String timeZoneDisplayName(bool isDST);
Ref<DateInstanceData> cachedDateInstanceData(double millisecondsFromEpoch);
void msToGregorianDateTime(double millisecondsFromEpoch, WTF::TimeType outputTimeType, GregorianDateTime&);
double gregorianDateTimeToMS(const GregorianDateTime&, double milliseconds, WTF::TimeType);
double localTimeToMS(double milliseconds, WTF::TimeType);
JS_EXPORT_PRIVATE double parseDate(JSGlobalObject*, VM&, const WTF::String&);
static void timeZoneChanged();
private:
class DSTCache {
public:
static constexpr unsigned cacheSize = 32;
// The implementation relies on the fact that no time zones have
// more than one daylight savings offset change per 19 days.
// In Egypt in 2010 they decided to suspend DST during Ramadan. This
// led to a short interval where DST is in effect from September 10 to
// September 30.
static constexpr int64_t defaultDSTDeltaInMilliseconds = 19 * WTF::Int64Milliseconds::secondsPerDay * 1000;
DSTCache()
: m_before(m_entries.data())
, m_after(m_entries.data() + 1)
{
}
uint64_t bumpEpoch()
{
++m_epoch;
return m_epoch;
}
void reset()
{
m_entries.fill(LocalTimeOffsetCache { });
m_before = m_entries.data();
m_after = m_entries.data() + 1;
m_epoch = 0;
}
LocalTimeOffset localTimeOffset(DateCache&, int64_t millisecondsFromEpoch, WTF::TimeType);
private:
LocalTimeOffsetCache* leastRecentlyUsed(LocalTimeOffsetCache* exclude);
std::tuple<LocalTimeOffsetCache*, LocalTimeOffsetCache*> probe(int64_t millisecondsFromEpoch);
void extendTheAfterCache(int64_t millisecondsFromEpoch, LocalTimeOffset);
uint64_t m_epoch { 0 };
std::array<LocalTimeOffsetCache, cacheSize> m_entries { };
LocalTimeOffsetCache* m_before;
LocalTimeOffsetCache* m_after;
};
struct YearMonthDayCache {
int32_t m_days { 0 };
int32_t m_year { 0 };
int32_t m_month { 0 };
int32_t m_day { 0 };
};
void timeZoneCacheSlow();
LocalTimeOffset localTimeOffset(int64_t millisecondsFromEpoch, WTF::TimeType inputTimeType = WTF::UTCTime)
{
static_assert(!WTF::UTCTime);
static_assert(WTF::LocalTime == 1);
return m_caches[static_cast<unsigned>(inputTimeType)].localTimeOffset(*this, millisecondsFromEpoch, inputTimeType);
}
LocalTimeOffset calculateLocalTimeOffset(double millisecondsFromEpoch, WTF::TimeType inputTimeType);
OpaqueICUTimeZone* timeZoneCache()
{
if (!m_timeZoneCache)
timeZoneCacheSlow();
return m_timeZoneCache.get();
}
std::tuple<int32_t, int32_t, int32_t> yearMonthDayFromDaysWithCache(int32_t days);
std::unique_ptr<OpaqueICUTimeZone, OpaqueICUTimeZoneDeleter> m_timeZoneCache;
std::array<DSTCache, 2> m_caches;
std::optional<YearMonthDayCache> m_yearMonthDayCache;
String m_cachedDateString;
double m_cachedDateStringValue;
DateInstanceCache m_dateInstanceCache;
uint64_t m_cachedTimezoneID { 0 };
String m_timeZoneStandardDisplayNameCache;
String m_timeZoneDSTDisplayNameCache;
};
ALWAYS_INLINE bool isUTCEquivalent(StringView timeZone)
{
return timeZone == "Etc/UTC"_s || timeZone == "Etc/GMT"_s || timeZone == "GMT"_s;
}
} // namespace JSC
WTF_ALLOW_UNSAFE_BUFFER_USAGE_END
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