1/*
2 * Copyright (c) 2022 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 SCOPE_GUARD_H
17#define SCOPE_GUARD_H
18
19namespace Updater {
20/*
21 * The RAII feature is used to implement scope exit protection so that resources
22 * can be released and the closure action can be performed in a unified manner when
23 * the scope exits.
24 */
25namespace Detail {
26template<typename ExitAction> class ScopeGuard {
27public:
28    ScopeGuard(ExitAction &&action) : action_(action), enable_(true) {}
29    ~ScopeGuard()
30    {
31        if (enable_) {
32            action_();
33        }
34    }
35
36    void Disable()
37    {
38        enable_ = false;
39    }
40
41private:
42    ExitAction action_;
43    bool enable_;
44};
45
46struct ScopeExitGuardHelper {};
47template<typename ExitAction>
48static inline ScopeGuard<ExitAction> operator + (ScopeExitGuardHelper, ExitAction &&action)
49{
50    return ScopeGuard<ExitAction>(std::forward<ExitAction>(action));
51}
52}
53
54#define ON_SCOPE_EXIT(id) auto onScopeExitGuard##id = Detail::ScopeExitGuardHelper {} + [ & ]
55
56#define CANCEL_SCOPE_EXIT_GUARD(id) onScopeExitGuard##id.Disable()
57}
58#endif
59