webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

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diff --git a/Source/JavaScriptCore/bytecode/DirectEvalCodeCache.h b/Source/JavaScriptCore/bytecode/DirectEvalCodeCache.h
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+++ b/Source/JavaScriptCore/bytecode/DirectEvalCodeCache.h
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+/*
+ * Copyright (C) 2008, 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.
+ * 3.  Neither the name of Apple Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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.
+ */
+
+#pragma once
+
+#include "DirectEvalExecutable.h"
+#include <wtf/HashMap.h>
+#include <wtf/RefPtr.h>
+#include <wtf/text/StringHash.h>
+
+namespace JSC {
+
+    class SlotVisitor;
+
+    class DirectEvalCodeCache {
+    public:
+        class CacheKey {
+        public:
+            CacheKey(const String& source, CallSiteIndex callSiteIndex)
+                : m_source(source.impl())
+                , m_callSiteIndex(callSiteIndex)
+            {
+            }
+
+            CacheKey(WTF::HashTableDeletedValueType)
+                : m_source(WTF::HashTableDeletedValue)
+            {
+            }
+
+            CacheKey() = default;
+
+            unsigned hash() const { return m_source->hash() ^ m_callSiteIndex.bits(); }
+
+            bool isEmptyValue() const { return !m_source; }
+
+            bool operator==(const CacheKey& other) const
+            {
+                return m_callSiteIndex == other.m_callSiteIndex && WTF::equal(m_source.get(), other.m_source.get());
+            }
+
+            bool isHashTableDeletedValue() const { return m_source.isHashTableDeletedValue(); }
+
+            struct Hash {
+                static unsigned hash(const CacheKey& key)
+                {
+                    return key.hash();
+                }
+                static bool equal(const CacheKey& lhs, const CacheKey& rhs)
+                {
+                    return lhs == rhs;
+                }
+                static const bool safeToCompareToEmptyOrDeleted = false;
+            };
+
+            typedef SimpleClassHashTraits<CacheKey> HashTraits;
+
+        private:
+            RefPtr<StringImpl> m_source;
+            CallSiteIndex m_callSiteIndex;
+        };
+
+        DirectEvalExecutable* tryGet(const String& evalSource, CallSiteIndex callSiteIndex)
+        {
+            return m_cacheMap.fastGet(CacheKey(evalSource, callSiteIndex)).get();
+        }
+        
+        void set(ExecState* exec, JSCell* owner, const String& evalSource, CallSiteIndex callSiteIndex, DirectEvalExecutable* evalExecutable)
+        {
+            if (m_cacheMap.size() < maxCacheEntries)
+                setSlow(exec, owner, evalSource, callSiteIndex, evalExecutable);
+        }
+
+        bool isEmpty() const { return m_cacheMap.isEmpty(); }
+
+        void visitAggregate(SlotVisitor&);
+
+        void clear();
+
+    private:
+        static const int maxCacheEntries = 64;
+
+        void setSlow(ExecState*, JSCell* owner, const String& evalSource, CallSiteIndex, DirectEvalExecutable*);
+
+        typedef HashMap<CacheKey, WriteBarrier<DirectEvalExecutable>, CacheKey::Hash, CacheKey::HashTraits> EvalCacheMap;
+        EvalCacheMap m_cacheMap;
+        Lock m_lock;
+    };
+
+} // namespace JSC