1/*
2 * Copyright (c) 2022-2024 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16#ifndef ECMASCRIPT_JS_WEAK_REF_H
17#define ECMASCRIPT_JS_WEAK_REF_H
18
19#include "ecmascript/ecma_context.h"
20#include "ecmascript/js_object.h"
21#include "ecmascript/js_tagged_value-inl.h"
22
23namespace panda::ecmascript {
24class JSWeakRef : public JSObject {
25public:
26    static JSWeakRef *Cast(TaggedObject *object)
27    {
28        ASSERT(JSTaggedValue(object).IsJSWeakRef());
29        return static_cast<JSWeakRef *>(object);
30    }
31
32    // 26.1.4.1 WeakRefDeref ( weakRef )
33    static JSTaggedValue WeakRefDeref(JSThread *thread, const JSHandle<JSWeakRef> &weakRef)
34    {
35        // 1. Let target be weakRef.[[WeakRefTarget]].
36        // 2. If target is not empty, then
37        //     a. Perform ! AddToKeptObjects(target).
38        //     b. Return target.
39        // 3. Return undefined.
40        JSHandle<JSTaggedValue> target(thread, weakRef->GetFromWeak());
41        if (!target->IsUndefined()) {
42            thread->GetCurrentEcmaContext()->AddToKeptObjects(target);
43        }
44        return target.GetTaggedValue();
45    }
46
47    void SetToWeak(JSThread *thread, JSTaggedValue value)
48    {
49        ALLOW_LOCAL_TO_SHARE_WEAK_REF_HANDLE;
50        JSTaggedValue weakObj = JSTaggedValue(value.CreateAndGetWeakRef());
51        ASSERT(weakObj.IsWeak());
52        SetWeakObject(thread, weakObj);
53    }
54
55    JSTaggedValue GetFromWeak() const
56    {
57        JSTaggedValue weakObj = GetWeakObject();
58        if (!weakObj.IsUndefined()) {
59            return JSTaggedValue(weakObj.GetWeakReferent());
60        }
61        return weakObj;
62    }
63    static constexpr size_t WEAK_OBJECT_OFFSET = JSObject::SIZE;
64    ACCESSORS(WeakObject, WEAK_OBJECT_OFFSET, SIZE)
65
66    DECL_VISIT_OBJECT_FOR_JS_OBJECT(JSObject, WEAK_OBJECT_OFFSET, SIZE)
67    DECL_DUMP()
68};
69} // namespace
70#endif // ECMASCRIPT_JS_WEAK_REF_H