mirror of
https://github.com/LadybirdBrowser/ladybird
synced 2026-04-25 17:25:08 +02:00
614713ed08
Replace the OwnPtr<IndexedPropertyStorage> indirection with inline indexed element storage directly on Object. This eliminates virtual dispatch and reduces indirection for indexed property access. The new system uses three storage kinds tracked by IndexedStorageKind: - Packed: Dense array, no holes. Elements stored in a malloced Value* array with capacity header (same layout as named properties). - Holey: Dense array with possible holes marked by empty sentinel. Same physical layout as Packed. - Dictionary: Sparse storage using GenericIndexedPropertyStorage, type-punned into the m_indexed_elements pointer. Transitions: None->Packed->Holey->Dictionary (mostly monotonic). Dictionary mode triggers on non-default attributes or sparse arrays. Object keeps the same 48-byte size since m_indexed_elements (8 bytes) replaces IndexedProperties (8 bytes), and the storage kind + array size fit in existing padding alongside m_flags. The asm interpreter benefits from one fewer indirection: it now reads the element pointer and array size directly from Object fields instead of chasing through OwnPtr -> IndexedPropertyStorage -> Vector. Removes: IndexedProperties, SimpleIndexedPropertyStorage, IndexedPropertyStorage, IndexedPropertyIterator. Keeps: GenericIndexedPropertyStorage (for Dictionary mode).
60 lines
1.4 KiB
C++
60 lines
1.4 KiB
C++
/*
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* Copyright (c) 2020, Matthew Olsson <mattco@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 <LibJS/Export.h>
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#include <LibJS/Runtime/Shape.h>
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#include <LibJS/Runtime/Value.h>
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namespace JS {
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struct ValueAndAttributes {
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Value value;
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PropertyAttributes attributes { default_attributes };
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Optional<u32> property_offset {};
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void visit_edges(Cell::Visitor& visitor)
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{
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visitor.visit(value);
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}
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};
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class GenericIndexedPropertyStorage {
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public:
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explicit GenericIndexedPropertyStorage()
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{
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}
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bool has_index(u32 index) const;
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Optional<ValueAndAttributes> get(u32 index) const;
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void put(u32 index, Value value, PropertyAttributes attributes = default_attributes);
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void remove(u32 index);
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ValueAndAttributes take_first();
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ValueAndAttributes take_last();
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size_t size() const { return m_sparse_elements.size(); }
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size_t array_like_size() const { return m_array_size; }
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bool set_array_like_size(size_t new_size);
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void visit_edges(Cell::Visitor& visitor)
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{
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for (auto& element : m_sparse_elements)
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element.value.visit_edges(visitor);
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}
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HashMap<u32, ValueAndAttributes> const& sparse_elements() const { return m_sparse_elements; }
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private:
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size_t m_array_size { 0 };
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HashMap<u32, ValueAndAttributes> m_sparse_elements;
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};
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}
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