1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
/*
* Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/HashMap.h>
#include <AK/OwnPtr.h>
#include <AK/WeakPtr.h>
#include <AK/Weakable.h>
#include <LibJS/Forward.h>
#include <LibJS/Heap/Cell.h>
#include <LibJS/Runtime/PropertyAttributes.h>
#include <LibJS/Runtime/StringOrSymbol.h>
#include <LibJS/Runtime/Value.h>
namespace JS {
struct PropertyMetadata {
u32 offset { 0 };
PropertyAttributes attributes { 0 };
};
struct TransitionKey {
StringOrSymbol property_key;
PropertyAttributes attributes { 0 };
bool operator==(const TransitionKey& other) const
{
return property_key == other.property_key && attributes == other.attributes;
}
};
class Shape final
: public Cell
, public Weakable<Shape> {
public:
virtual ~Shape() override;
enum class TransitionType {
Invalid,
Put,
Configure,
Prototype,
};
enum class ShapeWithoutGlobalObjectTag { Tag };
explicit Shape(ShapeWithoutGlobalObjectTag);
explicit Shape(Object& global_object);
Shape(Shape& previous_shape, const StringOrSymbol& property_key, PropertyAttributes attributes, TransitionType);
Shape(Shape& previous_shape, Object* new_prototype);
Shape* create_put_transition(const StringOrSymbol&, PropertyAttributes attributes);
Shape* create_configure_transition(const StringOrSymbol&, PropertyAttributes attributes);
Shape* create_prototype_transition(Object* new_prototype);
void add_property_without_transition(const StringOrSymbol&, PropertyAttributes);
void add_property_without_transition(PropertyKey const&, PropertyAttributes);
bool is_unique() const { return m_unique; }
Shape* create_unique_clone() const;
GlobalObject* global_object() const;
Object* prototype() { return m_prototype; }
const Object* prototype() const { return m_prototype; }
Optional<PropertyMetadata> lookup(const StringOrSymbol&) const;
const HashMap<StringOrSymbol, PropertyMetadata>& property_table() const;
u32 property_count() const { return m_property_count; }
struct Property {
StringOrSymbol key;
PropertyMetadata value;
};
Vector<Property> property_table_ordered() const;
void set_prototype_without_transition(Object* new_prototype) { m_prototype = new_prototype; }
void remove_property_from_unique_shape(const StringOrSymbol&, size_t offset);
void add_property_to_unique_shape(const StringOrSymbol&, PropertyAttributes attributes);
void reconfigure_property_in_unique_shape(const StringOrSymbol& property_key, PropertyAttributes attributes);
private:
virtual const char* class_name() const override { return "Shape"; }
virtual void visit_edges(Visitor&) override;
Shape* get_or_prune_cached_forward_transition(TransitionKey const&);
Shape* get_or_prune_cached_prototype_transition(Object* prototype);
void ensure_property_table() const;
Object* m_global_object { nullptr };
mutable OwnPtr<HashMap<StringOrSymbol, PropertyMetadata>> m_property_table;
OwnPtr<HashMap<TransitionKey, WeakPtr<Shape>>> m_forward_transitions;
OwnPtr<HashMap<Object*, WeakPtr<Shape>>> m_prototype_transitions;
Shape* m_previous { nullptr };
StringOrSymbol m_property_key;
Object* m_prototype { nullptr };
u32 m_property_count { 0 };
PropertyAttributes m_attributes { 0 };
TransitionType m_transition_type : 6 { TransitionType::Invalid };
bool m_unique : 1 { false };
};
}
template<>
struct AK::Traits<JS::TransitionKey> : public GenericTraits<JS::TransitionKey> {
static unsigned hash(const JS::TransitionKey& key)
{
return pair_int_hash(key.attributes.bits(), Traits<JS::StringOrSymbol>::hash(key.property_key));
}
};
|
