webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 145 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/runtime/JSPropertyNameEnumerator.h b/Source/JavaScriptCore/runtime/JSPropertyNameEnumerator.h
new file mode 100644
index 000000000..5e1235985
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+++ b/Source/JavaScriptCore/runtime/JSPropertyNameEnumerator.h
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+/*
+ * Copyright (C) 2014, 2016 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. 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 INC. 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 "JSCell.h"
+#include "Operations.h"
+#include "PropertyNameArray.h"
+#include "Structure.h"
+
+namespace JSC {
+
+class JSPropertyNameEnumerator final : public JSCell {
+public:
+    typedef JSCell Base;
+    static const unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;
+
+    static JSPropertyNameEnumerator* create(VM&);
+    static JSPropertyNameEnumerator* create(VM&, Structure*, uint32_t, uint32_t, PropertyNameArray&&);
+
+    static const bool needsDestruction = true;
+    static void destroy(JSCell*);
+
+    static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
+    {
+        return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
+    }
+
+    DECLARE_EXPORT_INFO;
+
+    JSString* propertyNameAtIndex(uint32_t index) const
+    {
+        if (index >= m_propertyNames.size())
+            return nullptr;
+        return m_propertyNames[index].get();
+    }
+
+    StructureChain* cachedPrototypeChain() const { return m_prototypeChain.get(); }
+    void setCachedPrototypeChain(VM& vm, StructureChain* prototypeChain) { return m_prototypeChain.set(vm, this, prototypeChain); }
+
+    Structure* cachedStructure(VM& vm) const
+    {
+        if (!m_cachedStructureID)
+            return nullptr;
+        return vm.heap.structureIDTable().get(m_cachedStructureID);
+    }
+    StructureID cachedStructureID() const { return m_cachedStructureID; }
+    uint32_t indexedLength() const { return m_indexedLength; }
+    uint32_t endStructurePropertyIndex() const { return m_endStructurePropertyIndex; }
+    uint32_t endGenericPropertyIndex() const { return m_endGenericPropertyIndex; }
+    uint32_t cachedInlineCapacity() const { return m_cachedInlineCapacity; }
+    static ptrdiff_t cachedStructureIDOffset() { return OBJECT_OFFSETOF(JSPropertyNameEnumerator, m_cachedStructureID); }
+    static ptrdiff_t indexedLengthOffset() { return OBJECT_OFFSETOF(JSPropertyNameEnumerator, m_indexedLength); }
+    static ptrdiff_t endStructurePropertyIndexOffset() { return OBJECT_OFFSETOF(JSPropertyNameEnumerator, m_endStructurePropertyIndex); }
+    static ptrdiff_t endGenericPropertyIndexOffset() { return OBJECT_OFFSETOF(JSPropertyNameEnumerator, m_endGenericPropertyIndex); }
+    static ptrdiff_t cachedInlineCapacityOffset() { return OBJECT_OFFSETOF(JSPropertyNameEnumerator, m_cachedInlineCapacity); }
+    static ptrdiff_t cachedPropertyNamesVectorOffset()
+    {
+        return OBJECT_OFFSETOF(JSPropertyNameEnumerator, m_propertyNames) + Vector<WriteBarrier<JSString>>::dataMemoryOffset();
+    }
+
+    static void visitChildren(JSCell*, SlotVisitor&);
+
+private:
+    JSPropertyNameEnumerator(VM&, StructureID, uint32_t);
+    void finishCreation(VM&, uint32_t, uint32_t, RefPtr<PropertyNameArrayData>&&);
+
+    Vector<WriteBarrier<JSString>> m_propertyNames;
+    StructureID m_cachedStructureID;
+    WriteBarrier<StructureChain> m_prototypeChain;
+    uint32_t m_indexedLength;
+    uint32_t m_endStructurePropertyIndex;
+    uint32_t m_endGenericPropertyIndex;
+    uint32_t m_cachedInlineCapacity;
+};
+
+inline JSPropertyNameEnumerator* propertyNameEnumerator(ExecState* exec, JSObject* base)
+{
+    VM& vm = exec->vm();
+    auto scope = DECLARE_THROW_SCOPE(vm);
+
+    uint32_t indexedLength = base->methodTable(vm)->getEnumerableLength(exec, base);
+
+    JSPropertyNameEnumerator* enumerator = nullptr;
+
+    Structure* structure = base->structure(vm);
+    if (!indexedLength
+        && (enumerator = structure->cachedPropertyNameEnumerator())
+        && enumerator->cachedPrototypeChain() == structure->prototypeChain(exec))
+        return enumerator;
+
+    uint32_t numberStructureProperties = 0;
+
+    PropertyNameArray propertyNames(exec, PropertyNameMode::Strings);
+
+    if (structure->canAccessPropertiesQuicklyForEnumeration() && indexedLength == base->getArrayLength()) {
+        base->methodTable(vm)->getStructurePropertyNames(base, exec, propertyNames, EnumerationMode());
+        ASSERT(!scope.exception());
+
+        numberStructureProperties = propertyNames.size();
+
+        base->methodTable(vm)->getGenericPropertyNames(base, exec, propertyNames, EnumerationMode());
+        ASSERT(!scope.exception());
+    } else {
+        // Generic property names vector contains all indexed property names.
+        // So disable indexed property enumeration phase by setting |indexedLength| to 0.
+        indexedLength = 0;
+        base->methodTable(vm)->getPropertyNames(base, exec, propertyNames, EnumerationMode());
+        RETURN_IF_EXCEPTION(scope, nullptr);
+    }
+
+    ASSERT(propertyNames.size() < UINT32_MAX);
+
+    normalizePrototypeChain(exec, structure);
+
+    enumerator = JSPropertyNameEnumerator::create(vm, structure, indexedLength, numberStructureProperties, WTFMove(propertyNames));
+    enumerator->setCachedPrototypeChain(vm, structure->prototypeChain(exec));
+    if (!indexedLength && structure->canCachePropertyNameEnumerator())
+        structure->setCachedPropertyNameEnumerator(vm, enumerator);
+    return enumerator;
+}
+
+} // namespace JSC