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authorSteve Block <steveblock@google.com>2009-11-05 09:23:40 +0000
committerSteve Block <steveblock@google.com>2009-11-10 22:41:12 +0000
commitcac0f67c402d107cdb10971b95719e2ff9c7c76b (patch)
treed182c7f87211c6f201a5f038e332336493ebdbe7 /JavaScriptCore/runtime/DateInstanceCache.h
parent4b2ef0f288e7c6c4602f621b7a0e9feed304b70e (diff)
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Merge webkit.org at r50258 : Initial merge by git.
Change-Id: I1a9e1dc4ed654b69174ad52a4f031a07240f37b0
Diffstat (limited to 'JavaScriptCore/runtime/DateInstanceCache.h')
-rw-r--r--JavaScriptCore/runtime/DateInstanceCache.h89
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diff --git a/JavaScriptCore/runtime/DateInstanceCache.h b/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 <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