webkitgtk-2.10.2webkitgtk-2.10.2

1 files changed, 93 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/runtime/DateInstanceCache.h b/Source/JavaScriptCore/runtime/DateInstanceCache.h
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+++ b/Source/JavaScriptCore/runtime/DateInstanceCache.h
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+/*
+ * 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 "JSCJSValue.h"
+#include "JSDateMath.h"
+#include <array>
+#include <wtf/HashFunctions.h>
+#include <wtf/RefCounted.h>
+
+namespace JSC {
+
+class DateInstanceData : public RefCounted<DateInstanceData> {
+public:
+    static Ref<DateInstanceData> create() { return adoptRef(*new DateInstanceData); }
+
+    double m_gregorianDateTimeCachedForMS;
+    GregorianDateTime m_cachedGregorianDateTime;
+    double m_gregorianDateTimeUTCCachedForMS;
+    GregorianDateTime m_cachedGregorianDateTimeUTC;
+
+private:
+    DateInstanceData()
+        : m_gregorianDateTimeCachedForMS(PNaN)
+        , m_gregorianDateTimeUTCCachedForMS(PNaN)
+    {
+    }
+};
+
+class DateInstanceCache {
+public:
+    DateInstanceCache()
+    {
+        reset();
+    }
+
+    void reset()
+    {
+        for (size_t i = 0; i < cacheSize; ++i)
+            m_cache[i].key = PNaN;
+    }
+
+    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 = 16;
+
+    struct CacheEntry {
+        double key;
+        RefPtr<DateInstanceData> value;
+    };
+
+    CacheEntry& lookup(double d) { return m_cache[WTF::FloatHash<double>::hash(d) & (cacheSize - 1)]; }
+
+    std::array<CacheEntry, cacheSize> m_cache;
+};
+
+} // namespace JSC
+
+#endif // DateInstanceCache_h