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/**
* 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 <boost/optional.hpp>
#include <vector>
#include "mongo/db/matcher/expression.h"
#include "mongo/db/matcher/expression_tree.h"
#include "mongo/db/matcher/rewrite_expr.h"
#include "mongo/db/pipeline/expression.h"
#include "mongo/db/pipeline/expression_context.h"
#include "mongo/db/pipeline/expression_walker.h"
#include "mongo/util/assert_util.h"
namespace mongo {
/**
* MatchExpression for the top-level $expr keyword. Take an expression as an argument, evaluates and
* coerces to boolean form which determines whether a document is a match.
*/
class ExprMatchExpression final : public MatchExpression {
public:
ExprMatchExpression(BSONElement elem,
const boost::intrusive_ptr<ExpressionContext>& expCtx,
clonable_ptr<ErrorAnnotation> annotation = nullptr);
ExprMatchExpression(boost::intrusive_ptr<Expression> expr,
const boost::intrusive_ptr<ExpressionContext>& expCtx,
clonable_ptr<ErrorAnnotation> annotation = nullptr);
bool matchesSingleElement(const BSONElement& e, MatchDetails* details = nullptr) const final {
MONGO_UNREACHABLE;
}
bool matches(const MatchableDocument* doc, MatchDetails* details = nullptr) const final;
/**
* Evaluates the aggregation expression of this match expression on document 'doc' and returns
* the result.
*/
Value evaluateExpression(const MatchableDocument* doc) const;
std::unique_ptr<MatchExpression> clone() const final;
void debugString(StringBuilder& debug, int indentationLevel = 0) const final {
_debugAddSpace(debug, indentationLevel);
debug << "$expr " << _expression->serialize(false).toString();
_debugStringAttachTagInfo(&debug);
}
void serialize(BSONObjBuilder* out, SerializationOptions opts) const final;
bool isTriviallyTrue() const final;
bool equivalent(const MatchExpression* other) const final;
MatchCategory getCategory() const final {
return MatchCategory::kOther;
}
size_t numChildren() const final {
return 0;
}
MatchExpression* getChild(size_t i) const final {
MONGO_UNREACHABLE_TASSERT(6400207);
}
void resetChild(size_t, MatchExpression*) {
MONGO_UNREACHABLE;
};
std::vector<std::unique_ptr<MatchExpression>>* getChildVector() final {
return nullptr;
}
boost::intrusive_ptr<ExpressionContext> getExpressionContext() const {
return _expCtx;
}
boost::intrusive_ptr<Expression> getExpression() const {
return _expression;
}
/**
* Use if the caller needs to modify the expression held by this $expr.
*/
boost::intrusive_ptr<Expression>& getExpressionRef() {
return _expression;
}
void acceptVisitor(MatchExpressionMutableVisitor* visitor) final {
visitor->visit(this);
}
void acceptVisitor(MatchExpressionConstVisitor* visitor) const final {
visitor->visit(this);
}
/**
* Finds an applicable rename from 'renameList' (if one exists) and applies it to the
* expression. Each pair in 'renameList' specifies a path prefix that should be renamed (as the
* first element) and the path components that should replace the renamed prefix (as the second
* element).
*/
void applyRename(const StringMap<std::string>& renameList) {
SubstituteFieldPathWalker substituteWalker(renameList);
expression_walker::walk<Expression>(_expression.get(), &substituteWalker);
}
private:
ExpressionOptimizerFunc getOptimizer() const final;
void _doSetCollator(const CollatorInterface* collator) final;
boost::intrusive_ptr<ExpressionContext> _expCtx;
boost::intrusive_ptr<Expression> _expression;
boost::optional<RewriteExpr::RewriteResult> _rewriteResult;
};
} // namespace mongo
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