1 /*
2  * Copyright (c) 2023 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 #ifndef HDI_DEVICE_INTELL_VOICE_SCOPE_GUARD_H
16 #define HDI_DEVICE_INTELL_VOICE_SCOPE_GUARD_H
17 
18 #include <utility>
19 
20 namespace OHOS {
21 namespace IntelligentVoice {
22 namespace Utils {
23 template <typename Func>
24 class ScopeGuard {
25 public:
ScopeGuard(Func && f)26     ScopeGuard(Func &&f) : func_(std::forward<Func>(f)), active_(true)
27     {
28     }
29 
ScopeGuard(ScopeGuard && rhs)30     ScopeGuard(ScopeGuard &&rhs) : func_(std::move(rhs.func)), active_(rhs.active_)
31     {
32         rhs.Disable();
33     }
34 
~ScopeGuard()35     ~ScopeGuard()
36     {
37         if (active_) {
38             func_();
39         }
40     }
41 
Disable()42     void Disable()
43     {
44         active_ = false;
45     }
46 
Active()47     bool Active() const
48     {
49         return active_;
50     }
51 
EarlyExit()52     void EarlyExit()
53     {
54         if (active_) {
55             func_();
56         }
57         active_ = false;
58     }
59 private:
60     Func func_;
61     bool active_;
62     ScopeGuard() = delete;
63     ScopeGuard(const ScopeGuard &) = delete;
64     ScopeGuard &operator=(const ScopeGuard &) = delete;
65     ScopeGuard &operator=(ScopeGuard &&) = delete;
66 };
67 
68 // tag dispatch
69 struct ScopeGuardOnExit {};
70 
71 template <typename Func>
72 inline ScopeGuard<Func> operator+(ScopeGuardOnExit, Func &&fn)
73 {
74     return ScopeGuard<Func>(std::forward<Func>(fn));
75 }
76 }
77 }
78 }
79 
80 /*
81  * ScopeGuard ensure the specified function which is created by ON_SCOPE_EXIT is executed no matter how the current
82  * scope exit.
83  * when use ON_SCOPE_EXIT macro, the format is:
84  * ON_SCOPE_EXIT {
85  *     your code
86  * };
87 */
88 #define ON_SCOPE_EXIT \
89     auto __onScopeGuardExit__ = OHOS::IntelligentVoice::Utils::ScopeGuardOnExit() + [&]()
90 
91 #define CANCEL_SCOPE_EXIT \
92     (__onScopeGuardExit__.Disable())
93 
94 #define EARLY_SCOPE_EXIT \
95     (__onScopeGuardExit__.EarlyExit())
96 
97 #define ON_SCOPE_EXIT_WITH_NAME(variable_name) \
98     auto variable_name = OHOS::IntelligentVoice::Utils::ScopeGuardOnExit() + [&]()
99 
100 #endif
101