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 
16 #ifndef HIVIEW_BASE_EVENT_STORE_SYS_EVENT_DOC_LRU_CACHE_H
17 #define HIVIEW_BASE_EVENT_STORE_SYS_EVENT_DOC_LRU_CACHE_H
18 
19 #include <list>
20 #include <memory>
21 
22 #include <string>
23 #include <unordered_map>
24 
25 #include "sys_event_doc.h"
26 
27 namespace OHOS {
28 namespace HiviewDFX {
29 namespace EventStore {
30 class SysEventDocLruCache {
31 public:
32     typedef std::pair<std::string, std::string> LruCacheKey;
33     typedef std::shared_ptr<SysEventDoc> LruCacheValue;
34 
SysEventDocLruCache(size_t capacity)35     explicit SysEventDocLruCache(size_t capacity) : capacity_(capacity) {}
~SysEventDocLruCache()36     ~SysEventDocLruCache() {}
37 
38     bool Contain(const LruCacheKey& key) const;
39     LruCacheValue Get(const LruCacheKey& key);
40     bool Add(const LruCacheKey& key, const LruCacheValue& value);
41     bool Remove(const LruCacheKey& key);
42     void Clear();
43 
44 private:
45     typedef std::pair<std::list<LruCacheKey>::iterator, LruCacheValue> LruCacheValuePair;
46     struct LruCacheKeyHashfunc {
operatorLruCacheKeyHashfunc47         size_t operator() (const std::pair<std::string, std::string>& keyPair) const
48         {
49             return std::hash<std::string>()(keyPair.first) ^ std::hash<std::string>()(keyPair.second);
50         }
51     };
52 
53     size_t capacity_;
54     std::list<LruCacheKey> lruList_;
55     std::unordered_map<LruCacheKey, LruCacheValuePair, LruCacheKeyHashfunc> lruCache_;
56 }; // SysEventDocLruCache
57 } // EventStore
58 } // HiviewDFX
59 } // OHOS
60 #endif // HIVIEW_BASE_EVENT_STORE_SYS_EVENT_DOC_LRU_CACHE_H
61