5eef07d232
We were doing a *lot* of string-to-int conversion while creating a new global object. This happened because Object::put() would try to convert the property name (string) to an integer to see if it refers to an indexed property. Sidestep this issue by using PropertyName for the CommonPropertyNames struct on VM (vm.names.foo), and giving PropertyName a flag that tells us whether it's a string that *may be* a number. All CommonPropertyNames are set up so they are known to not be numbers.
118 lines
3.6 KiB
C++
118 lines
3.6 KiB
C++
/*
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* Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/HashMap.h>
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#include <AK/OwnPtr.h>
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#include <AK/WeakPtr.h>
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#include <AK/Weakable.h>
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#include <LibJS/Forward.h>
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#include <LibJS/Heap/Cell.h>
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#include <LibJS/Runtime/PropertyAttributes.h>
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#include <LibJS/Runtime/StringOrSymbol.h>
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#include <LibJS/Runtime/Value.h>
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namespace JS {
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struct PropertyMetadata {
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size_t offset { 0 };
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PropertyAttributes attributes { 0 };
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};
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struct TransitionKey {
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StringOrSymbol property_name;
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PropertyAttributes attributes { 0 };
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bool operator==(const TransitionKey& other) const
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{
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return property_name == other.property_name && attributes == other.attributes;
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}
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};
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class Shape final
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: public Cell
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, public Weakable<Shape> {
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public:
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virtual ~Shape() override;
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enum class TransitionType {
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Invalid,
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Put,
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Configure,
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Prototype,
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};
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enum class ShapeWithoutGlobalObjectTag { Tag };
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explicit Shape(ShapeWithoutGlobalObjectTag);
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explicit Shape(Object& global_object);
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Shape(Shape& previous_shape, const StringOrSymbol& property_name, PropertyAttributes attributes, TransitionType);
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Shape(Shape& previous_shape, Object* new_prototype);
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Shape* create_put_transition(const StringOrSymbol&, PropertyAttributes attributes);
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Shape* create_configure_transition(const StringOrSymbol&, PropertyAttributes attributes);
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Shape* create_prototype_transition(Object* new_prototype);
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void add_property_without_transition(const StringOrSymbol&, PropertyAttributes);
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void add_property_without_transition(PropertyName const&, PropertyAttributes);
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bool is_unique() const { return m_unique; }
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Shape* create_unique_clone() const;
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GlobalObject* global_object() const;
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Object* prototype() { return m_prototype; }
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const Object* prototype() const { return m_prototype; }
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Optional<PropertyMetadata> lookup(const StringOrSymbol&) const;
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const HashMap<StringOrSymbol, PropertyMetadata>& property_table() const;
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size_t property_count() const;
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struct Property {
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StringOrSymbol key;
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PropertyMetadata value;
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};
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Vector<Property> property_table_ordered() const;
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void set_prototype_without_transition(Object* new_prototype) { m_prototype = new_prototype; }
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void remove_property_from_unique_shape(const StringOrSymbol&, size_t offset);
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void add_property_to_unique_shape(const StringOrSymbol&, PropertyAttributes attributes);
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void reconfigure_property_in_unique_shape(const StringOrSymbol& property_name, PropertyAttributes attributes);
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private:
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virtual const char* class_name() const override { return "Shape"; }
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virtual void visit_edges(Visitor&) override;
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Shape* get_or_prune_cached_forward_transition(TransitionKey const&);
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void ensure_property_table() const;
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PropertyAttributes m_attributes { 0 };
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TransitionType m_transition_type : 6 { TransitionType::Invalid };
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bool m_unique : 1 { false };
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Object* m_global_object { nullptr };
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mutable OwnPtr<HashMap<StringOrSymbol, PropertyMetadata>> m_property_table;
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HashMap<TransitionKey, WeakPtr<Shape>> m_forward_transitions;
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Shape* m_previous { nullptr };
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StringOrSymbol m_property_name;
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Object* m_prototype { nullptr };
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size_t m_property_count { 0 };
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};
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}
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template<>
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struct AK::Traits<JS::TransitionKey> : public GenericTraits<JS::TransitionKey> {
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static unsigned hash(const JS::TransitionKey& key)
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{
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return pair_int_hash(key.attributes.bits(), Traits<JS::StringOrSymbol>::hash(key.property_name));
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}
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};
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