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 <boost/optional.hpp> 34 #include <limits> 35 #include <vector> 36 37 #include "mongo/db/update/modifier_node.h" 38 #include "mongo/db/update/push_sorter.h" 39 #include "mongo/stdx/memory.h" 40 41 namespace mongo { 42 43 class PushNode final : public ModifierNode { 44 public: PushNode()45 PushNode() 46 : _slice(std::numeric_limits<long long>::max()), 47 _position(std::numeric_limits<long long>::max()) {} 48 Status init(BSONElement modExpr, const boost::intrusive_ptr<ExpressionContext>& expCtx) final; 49 clone()50 std::unique_ptr<UpdateNode> clone() const final { 51 return stdx::make_unique<PushNode>(*this); 52 } 53 setCollator(const CollatorInterface * collator)54 void setCollator(const CollatorInterface* collator) final { 55 if (_sort) { 56 invariant(!_sort->collator); 57 _sort->collator = collator; 58 } 59 } 60 61 protected: 62 ModifyResult updateExistingElement(mutablebson::Element* element, 63 std::shared_ptr<FieldRef> elementPath) const final; 64 void setValueForNewElement(mutablebson::Element* element) const final; 65 void logUpdate(LogBuilder* logBuilder, 66 StringData pathTaken, 67 mutablebson::Element element, 68 ModifyResult modifyResult) const final; 69 allowCreation()70 bool allowCreation() const final { 71 return true; 72 } 73 74 75 private: 76 // A helper for performPush(). 77 static ModifyResult insertElementsWithPosition(mutablebson::Element* array, 78 long long position, 79 const std::vector<BSONElement>& valuesToPush); 80 81 /** 82 * Inserts the elements from '_valuesToPush' in the 'element' array using '_position' to 83 * determine where to insert. This function also applies any '_slice' and or '_sort' that is 84 * specified. The return value of this function will indicate to logUpdate() what kind of oplog 85 * entries should be generated. 86 * 87 * Returns: 88 * - ModifyResult::kNoOp if '_valuesToPush' is empty and no slice or sort gets performed; 89 * - ModifyResult::kArrayAppendUpdate if the 'elements' array is initially non-empty, all 90 * inserted values are appended to the end, and no slice or sort gets performed; or 91 * - ModifyResult::kNormalUpdate if 'elements' is initially an empty array, values get 92 * inserted at the beginning or in the middle of the array, or a slice or sort gets 93 * performed. 94 */ 95 ModifyResult performPush(mutablebson::Element* element, FieldRef* elementPath) const; 96 97 static const StringData kEachClauseName; 98 static const StringData kSliceClauseName; 99 static const StringData kSortClauseName; 100 static const StringData kPositionClauseName; 101 102 std::vector<BSONElement> _valuesToPush; 103 long long _slice; 104 long long _position; 105 boost::optional<PatternElementCmp> _sort; 106 }; 107 108 } // namespace mongo 109