1 /*
2  * Copyright (c) 2021 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 STORAGE_ENGINE_MANAGER_H
17 #define STORAGE_ENGINE_MANAGER_H
18 
19 #include <string>
20 #include <map>
21 #include <mutex>
22 #include <set>
23 #include <condition_variable>
24 
25 #include "storage_engine.h"
26 
27 namespace DistributedDB {
28 class StorageEngineManager final {
29 public:
30     static StorageEngine *GetStorageEngine(const KvDBProperties &property, int &errCode);
31 
32     static int ReleaseStorageEngine(StorageEngine *storageEngine);
33 
34     static int ForceReleaseStorageEngine(const std::string &identifier);
35 
36     static int ExecuteMigration(StorageEngine *storageEngine);
37 
38     DISABLE_COPY_ASSIGN_MOVE(StorageEngineManager);
39 
40 private:
41     StorageEngineManager();
42     ~StorageEngineManager();
43 
44     // Get a StorageEngineManager instance, Singleton mode
45     static StorageEngineManager *GetInstance();
46 
47     int RegisterLockStatusListener();
48 
49     void LockStatusNotifier(bool isAccessControlled);
50 
51     StorageEngine *CreateStorageEngine(const KvDBProperties &property, int &errCode);
52 
53     StorageEngine *FindStorageEngine(const std::string &identifier);
54 
55     void InsertStorageEngine(const std::string &identifier, StorageEngine *&storageEngine);
56 
57     void EraseStorageEngine(const std::string &identifier);
58 
59     void ReleaseResources(const std::string &identifier);
60 
61     int ReleaseEngine(StorageEngine *releaseEngine);
62 
63     void EnterGetEngineProcess(const std::string &identifier);
64 
65     void ExitGetEngineProcess(const std::string &identifier);
66 
67     static std::mutex instanceLock_;
68     static std::atomic<StorageEngineManager *> instance_;
69     static volatile bool isRegLockStatusListener_;
70 
71     static std::mutex storageEnginesLock_;
72     std::map<std::string, StorageEngine *> storageEngines_;
73 
74     std::mutex getEngineMutex_;
75     std::condition_variable getEngineCondition_;
76     std::set<std::string> getEngineSet_;
77 
78     NotificationChain::Listener *lockStatusListener_;
79 };
80 } // namespace DistributedDB
81 
82 #endif // STORAGE_ENGINE_MANAGER_H
83