summaryrefslogtreecommitdiff
path: root/src/mongo/db/update/pull_node.cpp
blob: 5842718c3885373e57c25b10cacb55afb3bce233 (plain)
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
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
/**
 * 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.
 */

#include "mongo/platform/basic.h"

#include "mongo/db/update/pull_node.h"

#include "mongo/db/matcher/copyable_match_expression.h"
#include "mongo/db/matcher/extensions_callback_disallow_extensions.h"
#include "mongo/db/query/collation/collator_interface.h"

namespace mongo {

/**
 * The ObjectMatcher is used when the $pull condition is specified as an object and the first field
 * of that object is not an operator (like $gt).
 */
class PullNode::ObjectMatcher final : public PullNode::ElementMatcher {
public:
    ObjectMatcher(BSONObj matchCondition, const CollatorInterface* collator)
        : _matchExpr(
              matchCondition, stdx::make_unique<ExtensionsCallbackDisallowExtensions>(), collator) {
    }

    std::unique_ptr<ElementMatcher> clone() const final {
        return stdx::make_unique<ObjectMatcher>(*this);
    }

    bool match(const mutablebson::ConstElement& element) final {
        if (element.getType() == mongo::Object) {
            return _matchExpr->matchesBSON(element.getValueObject());
        } else {
            return false;
        }
    }

    void setCollator(const CollatorInterface* collator) final {
        _matchExpr.setCollator(collator);
    }

private:
    CopyableMatchExpression _matchExpr;
};

/**
 * The WrappedObjectMatcher is used when the condition is a regex or an object with an operator as
 * its first field (e.g., {$gt: ...}). It is possible that the element we want to compare is not an
 * object, so we wrap it in an object before comparing it. We also wrap the MatchExpression in an
 * empty object so that we are comparing the MatchCondition and the array element at the same level.
 * This hack allows us to use a MatchExpression to check a BSONElement.
 */
class PullNode::WrappedObjectMatcher final : public PullNode::ElementMatcher {
public:
    WrappedObjectMatcher(BSONElement matchCondition, const CollatorInterface* collator)
        : _matchExpr(matchCondition.wrap(""),
                     stdx::make_unique<ExtensionsCallbackDisallowExtensions>(),
                     collator) {}

    std::unique_ptr<ElementMatcher> clone() const final {
        return stdx::make_unique<WrappedObjectMatcher>(*this);
    }

    bool match(const mutablebson::ConstElement& element) final {
        BSONObj candidate = element.getValue().wrap("");
        return _matchExpr->matchesBSON(candidate);
    }

    void setCollator(const CollatorInterface* collator) final {
        _matchExpr.setCollator(collator);
    }

private:
    CopyableMatchExpression _matchExpr;
};

/**
 * The EqualityMatcher is used when the condition is a primitive value or an array value. We require
 * an exact match.
 */
class PullNode::EqualityMatcher final : public PullNode::ElementMatcher {
public:
    EqualityMatcher(BSONElement modExpr, const CollatorInterface* collator)
        : _modExpr(modExpr), _collator(collator) {}

    std::unique_ptr<ElementMatcher> clone() const final {
        return stdx::make_unique<EqualityMatcher>(*this);
    }

    bool match(const mutablebson::ConstElement& element) final {
        return (element.compareWithBSONElement(_modExpr, _collator, false) == 0);
    }

    void setCollator(const CollatorInterface* collator) final {
        _collator = collator;
    }

private:
    BSONElement _modExpr;
    const CollatorInterface* _collator;
};

Status PullNode::init(BSONElement modExpr, const CollatorInterface* collator) {
    invariant(modExpr.ok());

    try {
        if (modExpr.type() == mongo::Object &&
            !MatchExpressionParser::parsePathAcceptingKeyword(
                modExpr.embeddedObject().firstElement())) {
            _matcher = stdx::make_unique<ObjectMatcher>(modExpr.embeddedObject(), collator);
        } else if (modExpr.type() == mongo::Object || modExpr.type() == mongo::RegEx) {
            _matcher = stdx::make_unique<WrappedObjectMatcher>(modExpr, collator);
        } else {
            _matcher = stdx::make_unique<EqualityMatcher>(modExpr, collator);
        }
    } catch (AssertionException& exception) {
        return exception.toStatus();
    }

    return Status::OK();
}

}  // namespace mongo