1 /*
2  * Copyright (c) 2022-2023 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 
16 #ifndef ID_FACTORY_H
17 #define ID_FACTORY_H
18 
19 #include <set>
20 
21 #include "nocopyable.h"
22 
23 namespace OHOS {
24 namespace Msdp {
25 namespace DeviceStatus {
26 template<typename T>
27 class IdFactory {
28 public:
IdFactory()29     IdFactory() : IdFactory(1) {}
IdFactory(T seed)30     explicit IdFactory(T seed) : seed_(seed) {}
31     DISALLOW_COPY_AND_MOVE(IdFactory);
32     virtual ~IdFactory() = default;
33 
GenerateId()34     T GenerateId()
35     {
36         if (ids_.empty()) {
37             if (seed_ == maxLimit_) {
38                 return 0;
39             }
40             return seed_++;
41         }
42         T firstId = *ids_.begin();
43         ids_.erase(ids_.begin());
44         return firstId;
45     }
RecoveryId(T id)46     void RecoveryId(T id)
47     {
48         if (id > seed_) {
49             return;
50         }
51         ids_.insert(id);
52     }
53 
54 private:
55     T seed_ { 0 };
56     const T maxLimit_ = std::numeric_limits<T>::max();
57     std::set<T> ids_;
58 };
59 } // namespace DeviceStatus
60 } // namespace Msdp
61 } // namespace OHOS
62 #endif // ID_FACTORY_H
63