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