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 KV_STORE_SNAPSHOT_DELEGATE_H
17 #define KV_STORE_SNAPSHOT_DELEGATE_H
18 
19 #include <functional>
20 #include <vector>
21 
22 #include "store_types.h"
23 
24 namespace DistributedDB {
25 class KvStoreSnapshotDelegate {
26 public:
~KvStoreSnapshotDelegate()27     DB_API virtual ~KvStoreSnapshotDelegate() {}
28 
29     // Get a value from the snapshot with the given key.
30     // The return value is DBStatus and Value, these values will be passed to the callback.
31     DB_API virtual void Get(const Key &key, const std::function<void(DBStatus, const Value &)> &callback) const = 0;
32 
33     // Get entries from the snapshot  which keys start with keyPrefix.
34     // The return value is DBStatus and Value, these values will be passed to the callback.
35     DB_API virtual void GetEntries(const Key &keyPrefix,
36         const std::function<void(DBStatus, const std::vector<Entry> &)> &callback) const = 0;
37 };
38 } // namespace DistributedDB
39 
40 #endif // KV_STORE_SNAPSHOT_DELEGATE_H