1 /*
2 * Copyright (c) 2025 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 OHOS_CAMERA_DPS_ENABLE_SHARED_CREATE_H
17 #define OHOS_CAMERA_DPS_ENABLE_SHARED_CREATE_H
18
19 #include <memory>
20
21 namespace OHOS {
22 namespace CameraStandard {
23 namespace DeferredProcessing {
24 template <typename Class>
25 class EnableSharedCreate {
26 public:
27 virtual ~EnableSharedCreate() = default;
28
29 template <typename... Args>
Create(Args &&...args)30 static std::shared_ptr<Class> Create(Args&&...args)
31 {
32 struct MakeSharedHelper : Class {
33 explicit MakeSharedHelper(Args&&...args) : Class(std::forward<Args>(args)...) {}
34 };
35
36 std::shared_ptr<Class> sharedObj = std::make_shared<MakeSharedHelper>(std::forward<Args>(args)...);
37 EnableSharedFromThis(sharedObj, static_cast<EnableSharedCreate*>(sharedObj.get()));
38 return sharedObj;
39 }
40
shared_from_this()41 std::shared_ptr<Class> shared_from_this()
42 {
43 return std::shared_ptr<Class>(this->weakThis_);
44 }
45
shared_from_this()46 std::shared_ptr<const Class> shared_from_this() const
47 {
48 return std::shared_ptr<const Class>(this->weakThis_);
49 }
50
weak_from_this()51 std::weak_ptr<Class> weak_from_this() noexcept
52 {
53 return this->weakThis_;
54 }
55
weak_from_this()56 std::weak_ptr<const Class> weak_from_this() const noexcept
57 {
58 return this->weakThis_;
59 }
60
61 protected:
InitWeakThis(const std::shared_ptr<Class> & weak)62 inline void InitWeakThis(const std::shared_ptr<Class>& weak)
63 {
64 weakThis_ = weak;
65 }
66
67 private:
68 template<typename X, typename Y>
69 friend void EnableSharedFromThis(const std::shared_ptr<X>& sp, Y* base);
70
71 mutable std::weak_ptr<Class> weakThis_;
72 };
73
74 template<typename X, typename Y>
EnableSharedFromThis(const std::shared_ptr<X> & sp,Y * base)75 void EnableSharedFromThis(const std::shared_ptr<X>& sp, Y* base)
76 {
77 if (base != nullptr) {
78 base->InitWeakThis(sp);
79 }
80 }
81
82 template <typename Class>
83 class EnableSharedCreateInit : public EnableSharedCreate<Class> {
84 public:
85 template <typename... Args>
Create(Args &&...args)86 static std::shared_ptr<Class> Create(Args&&...args)
87 {
88 auto sharedObj = EnableSharedCreate<Class>::Create(std::forward<Args>(args)...);
89 if (sharedObj && (sharedObj->Initialize() != 0)) {
90 sharedObj = nullptr;
91 }
92 return sharedObj;
93 }
94
95 virtual int32_t Initialize() = 0;
96 };
97 } // namespace DeferredProcessing
98 } // namespace CameraStandard
99 } // namespace OHOS
100 #endif // OHOS_CAMERA_DPS_ENABLE_SHARED_CREATE_H