1/*
2 * Copyright (C) 2013, 2016 Apple Inc. All rights reserved.
3 * Copyright (C) 2018 Igalia S.L.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (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 "JSCJSValue.h"
30#include "Weak.h"
31
32namespace JSC {
33
34class JSObject;
35class JSString;
36class WeakHandleOwner;
37
38class JSWeakValue {
39public:
40 JSWeakValue() = default;
41 ~JSWeakValue();
42
43 void clear();
44 bool isClear() const;
45
46 bool isSet() const { return m_tag != WeakTypeTag::NotSet; }
47 bool isPrimitive() const { return m_tag == WeakTypeTag::Primitive; }
48 bool isObject() const { return m_tag == WeakTypeTag::Object; }
49 bool isString() const { return m_tag == WeakTypeTag::String; }
50
51 void setPrimitive(JSValue);
52 void setObject(JSObject*, WeakHandleOwner&, void* context);
53 void setString(JSString*, WeakHandleOwner&, void* context);
54
55 JSObject* object() const
56 {
57 ASSERT(isObject());
58 return m_value.object.get();
59 }
60
61 JSValue primitive() const
62 {
63 ASSERT(isPrimitive());
64 return m_value.primitive;
65 }
66
67 JSString* string() const
68 {
69 ASSERT(isString());
70 return m_value.string.get();
71 }
72
73private:
74 enum class WeakTypeTag { NotSet, Primitive, Object, String };
75
76 WeakTypeTag m_tag { WeakTypeTag::NotSet };
77
78 union WeakValueUnion {
79 WeakValueUnion()
80 : primitive(JSValue())
81 {
82 }
83
84 ~WeakValueUnion()
85 {
86 ASSERT(!primitive);
87 }
88
89 JSValue primitive;
90 Weak<JSObject> object;
91 Weak<JSString> string;
92 } m_value;
93};
94
95} // namespace JSC
96