1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include <memory>
#include "mongo/base/clonable_ptr.h"
#include "mongo/db/update/modifier_node.h"
namespace mongo {
/**
* An ArrayCullingNode represents an update modifier that removes elements from an array that match
* a predicate (condensing the array in the process), such as $pull and $pullAll. Modifiers with
* this behavior all use the same apply() logic (implemented in this class), which uses a
* subclass-supplied ElementMatcher to determine which array elements should be removed. The init
* method for each subclass must populate _matcher with an ElementMatcher implementation.
*/
class ArrayCullingNode : public ModifierNode {
public:
ModifyResult updateExistingElement(mutablebson::Element* element,
const FieldRef& elementPath) const final;
void validateUpdate(mutablebson::ConstElement updatedElement,
mutablebson::ConstElement leftSibling,
mutablebson::ConstElement rightSibling,
std::uint32_t recursionLevel,
ModifyResult modifyResult,
bool validateForStorage,
bool* containsDotsAndDollarsField) const final;
void setCollator(const CollatorInterface* collator) final {
_matcher->setCollator(collator);
}
protected:
/**
* ArrayCullingNode::apply() uses an ElementMatcher to determine which array elements meet the
* $pull condition. The different subclasses of ElementMatcher implement the different kinds of
* checks that can be used for a $pull operation.
*/
class ElementMatcher {
public:
virtual ~ElementMatcher() = default;
virtual std::unique_ptr<ElementMatcher> clone() const = 0;
virtual bool match(const mutablebson::ConstElement& element) = 0;
virtual void setCollator(const CollatorInterface* collator) = 0;
/**
* Retrieve the value the matcher applies as a single-element BSONObj with an empty string
* as the keyname. For example, for the input syntax: { $pull: { votes: { $gte: 6 } } },
* this function would return: { "": { $gte: 6 } } in BSON.
*/
virtual BSONObj value() const = 0;
};
clonable_ptr<ElementMatcher> _matcher;
private:
BSONObj operatorValue() const final {
return _matcher->value();
}
};
} // namespace mongo
|
