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Diffstat (limited to 'src/3rdparty/webkit/JavaScriptCore/runtime/DateInstanceCache.h')
-rw-r--r-- | src/3rdparty/webkit/JavaScriptCore/runtime/DateInstanceCache.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/src/3rdparty/webkit/JavaScriptCore/runtime/DateInstanceCache.h b/src/3rdparty/webkit/JavaScriptCore/runtime/DateInstanceCache.h new file mode 100644 index 0000000..b626c1d --- /dev/null +++ b/src/3rdparty/webkit/JavaScriptCore/runtime/DateInstanceCache.h @@ -0,0 +1,89 @@ +/* + * Copyright (C) 2009 Apple Inc. All Rights Reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. 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. + * + * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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. + */ + +#ifndef DateInstanceCache_h +#define DateInstanceCache_h + +#include <wtf/DateMath.h> +#include <wtf/HashFunctions.h> +#include <wtf/PassRefPtr.h> +#include <wtf/RefCounted.h> + +namespace JSC { + + extern const double NaN; + + class DateInstanceData : public RefCounted<DateInstanceData> { + public: + static PassRefPtr<DateInstanceData> create() { return adoptRef(new DateInstanceData); } + + double m_gregorianDateTimeCachedForMS; + WTF::GregorianDateTime m_cachedGregorianDateTime; + double m_gregorianDateTimeUTCCachedForMS; + WTF::GregorianDateTime m_cachedGregorianDateTimeUTC; + + private: + DateInstanceData() + : m_gregorianDateTimeCachedForMS(NaN) + , m_gregorianDateTimeUTCCachedForMS(NaN) + { + } + }; + + class DateInstanceCache { + public: + DateInstanceCache() + { + for (size_t i = 0; i < cacheSize; ++i) + m_cache[i].key = NaN; + } + + DateInstanceData* add(double d) + { + CacheEntry& entry = lookup(d); + if (d == entry.key) + return entry.value.get(); + + entry.key = d; + entry.value = DateInstanceData::create(); + return entry.value.get(); + } + + private: + static const size_t cacheSize = 64; + + struct CacheEntry { + double key; + RefPtr<DateInstanceData> value; + }; + + CacheEntry& lookup(double d) { return m_cache[WTF::FloatHash<double>::hash(d) & (cacheSize - 1)]; } + + CacheEntry m_cache[cacheSize]; + }; + +} // namespace JSC + +#endif // DateInstanceCache_h |