1 2 /** 3 * Copyright (C) 2018-present MongoDB, Inc. 4 * 5 * This program is free software: you can redistribute it and/or modify 6 * it under the terms of the Server Side Public License, version 1, 7 * as published by MongoDB, Inc. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * Server Side Public License for more details. 13 * 14 * You should have received a copy of the Server Side Public License 15 * along with this program. If not, see 16 * <http://www.mongodb.com/licensing/server-side-public-license>. 17 * 18 * As a special exception, the copyright holders give permission to link the 19 * code of portions of this program with the OpenSSL library under certain 20 * conditions as described in each individual source file and distribute 21 * linked combinations including the program with the OpenSSL library. You 22 * must comply with the Server Side Public License in all respects for 23 * all of the code used other than as permitted herein. If you modify file(s) 24 * with this exception, you may extend this exception to your version of the 25 * file(s), but you are not obligated to do so. If you do not wish to do so, 26 * delete this exception statement from your version. If you delete this 27 * exception statement from all source files in the program, then also delete 28 * it in the license file. 29 */ 30 31 #pragma once 32 33 #include "mongo/base/string_data_comparator_interface.h" 34 #include "mongo/bson/bsonelement_comparator_interface.h" 35 36 namespace mongo { 37 38 /** 39 * A BSONElement comparator that supports: 40 * - Ignoring field names during comparison. 41 * - Passing a custom string comparator. 42 */ 43 class BSONElementComparator final : public BSONElement::ComparatorInterface { 44 public: 45 enum class FieldNamesMode { 46 kConsider, 47 kIgnore, 48 }; 49 50 /** 51 * Constructs a BSONElement comparator. 52 * 53 * Will not consider the elements' field names in comparisons if 'fieldNamesMode' is kIgnore. 54 * 55 * If 'stringComparator' is null, uses default binary string comparison. Otherwise, 56 * 'stringComparator' is used for all string comparisons. 57 */ BSONElementComparator(FieldNamesMode fieldNamesMode,const StringData::ComparatorInterface * stringComparator)58 BSONElementComparator(FieldNamesMode fieldNamesMode, 59 const StringData::ComparatorInterface* stringComparator) 60 : _stringComparator(stringComparator), 61 _rules((fieldNamesMode == FieldNamesMode::kConsider) ? ComparisonRules::kConsiderFieldName 62 : 0) {} 63 compare(const BSONElement & lhs,const BSONElement & rhs)64 int compare(const BSONElement& lhs, const BSONElement& rhs) const final { 65 return lhs.woCompare(rhs, _rules, _stringComparator); 66 } 67 hash_combine(size_t & seed,const BSONElement & toHash)68 void hash_combine(size_t& seed, const BSONElement& toHash) const final { 69 hashCombineBSONElement(seed, toHash, _rules, _stringComparator); 70 } 71 72 private: 73 const StringData::ComparatorInterface* _stringComparator; 74 ComparisonRulesSet _rules; 75 }; 76 77 } // namespace mongo 78