jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#pragma once
28
29#include <AK/FlyString.h>
30#include <AK/HashMap.h>
31#include <AK/OwnPtr.h>
32#include <LibJS/Forward.h>
33#include <LibJS/Runtime/Cell.h>
34#include <LibJS/Runtime/Value.h>
35
36namespace JS {
37
38struct PropertyMetadata {
39 size_t offset { 0 };
40 u8 attributes { 0 };
41};
42
43class Shape final : public Cell {
44public:
45 virtual ~Shape() override;
46
47 Shape();
48 Shape(Shape* previous_shape, const FlyString& property_name, u8 property_attributes);
49 Shape(Shape* previous_shape, Object* new_prototype);
50
51 Shape* create_put_transition(const FlyString& name, u8 attributes);
52 Shape* create_prototype_transition(Object* new_prototype);
53
54 Object* prototype() { return m_prototype; }
55 const Object* prototype() const { return m_prototype; }
56
57 Optional<PropertyMetadata> lookup(const FlyString&) const;
58 const HashMap<FlyString, PropertyMetadata>& property_table() const;
59 size_t property_count() const;
60
61 void set_prototype_without_transition(Object* new_prototype) { m_prototype = new_prototype; }
62
63private:
64 virtual const char* class_name() const override { return "Shape"; }
65 virtual void visit_children(Visitor&) override;
66
67 void ensure_property_table() const;
68
69 mutable OwnPtr<HashMap<FlyString, PropertyMetadata>> m_property_table;
70
71 HashMap<FlyString, Shape*> m_forward_transitions;
72 Shape* m_previous { nullptr };
73 FlyString m_property_name;
74 u8 m_property_attributes { 0 };
75 Object* m_prototype { nullptr };
76};
77
78}