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 SQLITE_SINGLE_VER_RESULT_SET_H 17 #define SQLITE_SINGLE_VER_RESULT_SET_H 18 19 #include <mutex> 20 #include <vector> 21 22 #include "ikvdb_raw_cursor.h" 23 #include "kvdb_windowed_result_set.h" 24 #include "query_object.h" 25 26 namespace DistributedDB { 27 constexpr int INIT_POSITION = -1; 28 constexpr int DEFAULT_RESULT_SET_CACHE_MAX_SIZE = 1; // Unit MB, default 1 MB 29 constexpr int RESULT_SET_CACHE_MAX_SIZE_MIN = 1; 30 constexpr int RESULT_SET_CACHE_MAX_SIZE_MAX = 16; 31 enum class ResultSetType : int { 32 KEYPREFIX = 0, 33 QUERY = 1, 34 }; 35 // Forward declaration 36 class SQLiteSingleVerNaturalStore; 37 class SQLiteSingleVerStorageExecutor; 38 39 class SQLiteSingleVerResultSet : public KvDBWindowedResultSet { 40 public: 41 struct Option { 42 ResultSetCacheMode cacheMode = ResultSetCacheMode::CACHE_FULL_ENTRY; 43 int cacheMaxSize = DEFAULT_RESULT_SET_CACHE_MAX_SIZE; 44 }; 45 46 SQLiteSingleVerResultSet(SQLiteSingleVerNaturalStore *kvDB, const Key &keyPrefix, const Option& option); 47 SQLiteSingleVerResultSet(SQLiteSingleVerNaturalStore *kvDB, const QueryObject &queryObj, const Option& option); 48 ~SQLiteSingleVerResultSet() override; 49 50 // Delete the copy and assign constructors 51 DISABLE_COPY_ASSIGN_MOVE(SQLiteSingleVerResultSet); 52 53 // Initialize logic 54 int Open(bool isMemDb) override; 55 56 // Get total entries count. 57 // >= 0: count, < 0: errCode. 58 int GetCount() const override; 59 60 // Get current read position. 61 // >= 0: position, < 0: errCode 62 int GetPosition() const override; 63 64 // Move the read position to an absolute position value. 65 int MoveTo(int position) const override; 66 67 // Get the entry of current position. 68 int GetEntry(Entry &entry) const override; 69 70 // Finalize logic 71 void Close() override; 72 private: 73 int OpenForCacheFullEntryMode(bool isMemDb); 74 int OpenForCacheEntryIdMode(); 75 76 int MoveToForCacheFullEntryMode(int position) const; 77 int MoveToForCacheEntryIdMode(int position) const; 78 79 void CloseForCacheFullEntryMode(); 80 void CloseForCacheEntryIdMode(); 81 82 const Option option_; 83 84 // Common Part Of Two ResultSet Mode. 85 bool isOpen_ = false; 86 int count_ = 0; 87 mutable int position_ = INIT_POSITION; // The position in the overall result 88 mutable std::mutex mutex_; 89 90 // For KeyPrefix Type Or Query Type. 91 const ResultSetType type_ = ResultSetType::KEYPREFIX; 92 Key keyPrefix_; 93 mutable QueryObject queryObj_; // Some QueryObject member function need to call is not a const function(BAD...) 94 // Common Pointer For Use, Not Own it, Not Responsible To Release It. 95 SQLiteSingleVerNaturalStore *kvDB_ = nullptr; 96 97 // Cache Full Entry Mode Using ResultEntriesWindow and IKvDBRawCursor, Own It, Responsible To Release It. 98 ResultEntriesWindow *window_ = nullptr; 99 IKvDBRawCursor *rawCursor_ = nullptr; 100 101 // Cache EntryId Mode Using StorageExecutor, Own It, Responsible To Release It. 102 SQLiteSingleVerStorageExecutor *handle_ = nullptr; 103 mutable std::vector<int64_t> cachedRowIds_; 104 mutable int cacheStartPosition_ = INIT_POSITION; // The offset of the first cached rowid in all result rowids 105 }; 106 } // namespace DistributedDB 107 108 #endif // SQLITE_SINGLE_VER_RESULT_SET_H 109