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_DB_WINDOWED_RESULT_SET_H
17 #define KV_DB_WINDOWED_RESULT_SET_H
18 
19 #include "ikvdb_result_set.h"
20 #include "result_entries_window.h"
21 
22 namespace DistributedDB {
23 class KvDBWindowedResultSet : public IKvDBResultSet {
24 public:
25     KvDBWindowedResultSet();
26     ~KvDBWindowedResultSet() override;
27     DISABLE_COPY_ASSIGN_MOVE(KvDBWindowedResultSet);
28 
29     // Initialize logic
30     int Open(bool isMemDb) override;
31 
32     // Get total entries count.
33     // >= 0: count, < 0: errCode.
34     int GetCount() const override;
35 
36     // Get current read position.
37     // >= 0: position, < 0: errCode
38     int GetPosition() const override;
39 
40     int Move(int offset) const override;
41 
42     // Move the read position to an absolute position value.
43     int MoveTo(int position) const override;
44 
45     int MoveToFirst() override;
46 
47     int MoveToLast() override;
48 
49     bool IsFirst() const override;
50 
51     bool IsLast() const override;
52 
53     bool IsBeforeFirst() const override;
54 
55     bool IsAfterLast() const override;
56 
57     // Get the entry of current position.
58     int GetEntry(Entry &entry) const override;
59 
60     // Finalize logic
61     int Close() override;
62 
63 private:
64     ResultEntriesWindow *window_;
65 };
66 } // namespace DistributedDB
67 
68 #endif // KV_DB_WINDOWED_RESULT_SET_H
69