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
|
/**
* Copyright (C) 2017 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* 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 GNU Affero General 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 "mongo/db/update/update_leaf_node.h"
#include "mongo/stdx/memory.h"
namespace mongo {
/**
* A PathCreatingNode represents an update modifier that materializes the field it wants to update
* when that field does not already exist. This category of modifiers includes $set, $inc, and $mul.
* These nodes are very similar in operation, so most of their logic is in the apply() method of
* this abstract base class, which calls into a virtual methods for modifier-specific functionality.
*/
class PathCreatingNode : public UpdateLeafNode {
public:
void apply(mutablebson::Element element,
FieldRef* pathToCreate,
FieldRef* pathTaken,
StringData matchedField,
bool fromReplication,
const UpdateIndexData* indexData,
LogBuilder* logBuilder,
bool* indexesAffected,
bool* noop) const final;
protected:
/**
* PathCreatingNode::apply() calls the updateExistingElement() method when applying its update
* to an existing path. The child's implementation of this method is responsible for either
* updating the given Element or setting *noop to true to indicate that no update is necessary.
*/
virtual void updateExistingElement(mutablebson::Element* element, bool* noop) const = 0;
/**
* PathCreatingNode::apply() calls the setValueForNewElement() method when it must materialize a
* new field in order to apply its update. The child's implemenation of this method is
* responsible for assigning a value to the new element (which will initially be null).
*/
virtual void setValueForNewElement(mutablebson::Element* element) const = 0;
};
} // namespace mongo
|
