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
|
/**
* 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.
*/
#include "mongo/platform/basic.h"
#include "mongo/db/matcher/expression_expr.h"
#include "mongo/util/fail_point_service.h"
namespace mongo {
MONGO_FAIL_POINT_DEFINE(ExprMatchExpressionMatchesReturnsFalseOnException);
ExprMatchExpression::ExprMatchExpression(boost::intrusive_ptr<Expression> expr,
const boost::intrusive_ptr<ExpressionContext>& expCtx)
: MatchExpression(MatchType::EXPRESSION), _expCtx(expCtx), _expression(expr) {}
ExprMatchExpression::ExprMatchExpression(BSONElement elem,
const boost::intrusive_ptr<ExpressionContext>& expCtx)
: ExprMatchExpression(Expression::parseOperand(expCtx, elem, expCtx->variablesParseState),
expCtx) {}
bool ExprMatchExpression::matches(const MatchableDocument* doc, MatchDetails* details) const {
if (_rewriteResult && _rewriteResult->matchExpression() &&
!_rewriteResult->matchExpression()->matches(doc, details)) {
return false;
}
Document document(doc->toBSON());
// 'Variables' is not thread safe, and ExprMatchExpression may be used in a validator which
// processes documents from multiple threads simultaneously. Hence we make a copy of the
// 'Variables' object per-caller.
Variables variables = _expCtx->variables;
try {
auto value = _expression->evaluate(document, &variables);
return value.coerceToBool();
} catch (const DBException&) {
if (MONGO_FAIL_POINT(ExprMatchExpressionMatchesReturnsFalseOnException)) {
return false;
}
throw;
}
}
void ExprMatchExpression::serialize(BSONObjBuilder* out) const {
*out << "$expr" << _expression->serialize(false);
}
bool ExprMatchExpression::equivalent(const MatchExpression* other) const {
if (other->matchType() != matchType()) {
return false;
}
const ExprMatchExpression* realOther = static_cast<const ExprMatchExpression*>(other);
if (!CollatorInterface::collatorsMatch(_expCtx->getCollator(),
realOther->_expCtx->getCollator())) {
return false;
}
// TODO SERVER-30982: Add mechanism to allow for checking Expression equivalency.
return ValueComparator().evaluate(_expression->serialize(false) ==
realOther->_expression->serialize(false));
}
void ExprMatchExpression::_doSetCollator(const CollatorInterface* collator) {
_expCtx->setCollator(collator);
if (_rewriteResult && _rewriteResult->matchExpression()) {
_rewriteResult->matchExpression()->setCollator(collator);
}
}
std::unique_ptr<MatchExpression> ExprMatchExpression::shallowClone() const {
// TODO SERVER-31003: Replace Expression clone via serialization with Expression::clone().
BSONObjBuilder bob;
bob << "" << _expression->serialize(false);
boost::intrusive_ptr<Expression> clonedExpr =
Expression::parseOperand(_expCtx, bob.obj().firstElement(), _expCtx->variablesParseState);
auto clone = std::make_unique<ExprMatchExpression>(std::move(clonedExpr), _expCtx);
if (_rewriteResult) {
clone->_rewriteResult = _rewriteResult->clone();
}
return std::move(clone);
}
MatchExpression::ExpressionOptimizerFunc ExprMatchExpression::getOptimizer() const {
return [](std::unique_ptr<MatchExpression> expression) {
auto& exprMatchExpr = static_cast<ExprMatchExpression&>(*expression);
// If '_expression' can be rewritten to a MatchExpression, we will return a $and node with
// both the original ExprMatchExpression and the MatchExpression rewrite as children.
// Exiting early prevents additional calls to optimize from performing additional rewrites
// and adding duplicate MatchExpression sub-trees to the tree.
if (exprMatchExpr._rewriteResult) {
return expression;
}
exprMatchExpr._expression = exprMatchExpr._expression->optimize();
exprMatchExpr._rewriteResult =
RewriteExpr::rewrite(exprMatchExpr._expression, exprMatchExpr._expCtx->getCollator());
if (exprMatchExpr._rewriteResult->matchExpression()) {
auto andMatch = std::make_unique<AndMatchExpression>();
andMatch->add(exprMatchExpr._rewriteResult->releaseMatchExpression().release());
andMatch->add(expression.release());
// Re-optimize the new AND in order to make sure that any AND children are absorbed.
expression = MatchExpression::optimize(std::move(andMatch));
}
return expression;
};
}
} // namespace mongo
|
