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// expression_parser.h
/**
* Copyright (C) 2013 10gen 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/base/status.h"
#include "mongo/base/status_with.h"
#include "mongo/db/matcher/expression.h"
#include "mongo/db/matcher/expression_leaf.h"
#include "mongo/db/matcher/expression_tree.h"
#include "mongo/db/matcher/extensions_callback.h"
#include "mongo/stdx/functional.h"
namespace mongo {
class CollatorInterface;
class OperationContext;
class MatchExpressionParser {
public:
/**
* caller has to maintain ownership obj
* the tree has views (BSONElement) into obj
*/
static StatusWithMatchExpression parse(const BSONObj& obj,
const ExtensionsCallback& extensionsCallback,
const CollatorInterface* collator) {
const bool topLevelCall = true;
return MatchExpressionParser(&extensionsCallback)._parse(obj, collator, topLevelCall);
}
private:
MatchExpressionParser(const ExtensionsCallback* extensionsCallback)
: _extensionsCallback(extensionsCallback) {}
/**
* 5 = false
* { a : 5 } = false
* { $lt : 5 } = true
* { $ref: "s", $id: "x" } = false
* { $ref: "s", $id: "x", $db: "mydb" } = false
* { $ref : "s" } = false (if incomplete DBRef is allowed)
* { $id : "x" } = false (if incomplete DBRef is allowed)
* { $db : "mydb" } = false (if incomplete DBRef is allowed)
*/
bool _isExpressionDocument(const BSONElement& e, bool allowIncompleteDBRef);
/**
* { $ref: "s", $id: "x" } = true
* { $ref : "s" } = true (if incomplete DBRef is allowed)
* { $id : "x" } = true (if incomplete DBRef is allowed)
* { $db : "x" } = true (if incomplete DBRef is allowed)
*/
bool _isDBRefDocument(const BSONObj& obj, bool allowIncompleteDBRef);
/**
* Parse 'obj' and return either a MatchExpression or an error.
*
* 'collator' is the collator that constructed collation-aware MatchExpressions will use. It
* must outlive the returned MatchExpression and any clones made of it.
*
* 'topLevel' indicates whether or not the we are at the top level of the tree across recursive
* class to this function. This is used to apply special logic at the top level.
*/
StatusWithMatchExpression _parse(const BSONObj& obj,
const CollatorInterface* collator,
bool topLevel);
/**
* parses a field in a sub expression
* if the query is { x : { $gt : 5, $lt : 8 } }
* e is { $gt : 5, $lt : 8 }
*/
Status _parseSub(const char* name,
const BSONObj& obj,
AndMatchExpression* root,
const CollatorInterface* collator,
bool topLevel);
/**
* parses a single field in a sub expression
* if the query is { x : { $gt : 5, $lt : 8 } }
* e is $gt : 5
*/
StatusWithMatchExpression _parseSubField(const BSONObj& context,
const AndMatchExpression* andSoFar,
const char* name,
const BSONElement& e,
const CollatorInterface* collator,
bool topLevel);
StatusWithMatchExpression _parseComparison(const char* name,
ComparisonMatchExpression* cmp,
const BSONElement& e,
const CollatorInterface* collator);
StatusWithMatchExpression _parseMOD(const char* name, const BSONElement& e);
StatusWithMatchExpression _parseRegexElement(const char* name, const BSONElement& e);
StatusWithMatchExpression _parseRegexDocument(const char* name, const BSONObj& doc);
Status _parseInExpression(InMatchExpression* entries,
const BSONObj& theArray,
const CollatorInterface* collator);
StatusWithMatchExpression _parseType(const char* name, const BSONElement& elt);
// arrays
StatusWithMatchExpression _parseElemMatch(const char* name,
const BSONElement& e,
const CollatorInterface* collator,
bool topLevel);
StatusWithMatchExpression _parseAll(const char* name,
const BSONElement& e,
const CollatorInterface* collator,
bool topLevel);
// tree
Status _parseTreeList(const BSONObj& arr,
ListOfMatchExpression* out,
const CollatorInterface* collator,
bool topLevel);
StatusWithMatchExpression _parseNot(const char* name,
const BSONElement& e,
const CollatorInterface* collator,
bool topLevel);
/**
* Parses 'e' into a BitTestMatchExpression.
*/
template <class T>
StatusWithMatchExpression _parseBitTest(const char* name, const BSONElement& e);
/**
* Converts 'theArray', a BSONArray of integers, into a std::vector of integers.
*/
StatusWith<std::vector<uint32_t>> _parseBitPositionsArray(const BSONObj& theArray);
// The maximum allowed depth of a query tree. Just to guard against stack overflow.
static const int kMaximumTreeDepth;
// Performs parsing for the match extensions. We do not own this pointer - it has to live
// as long as the parser is active.
const ExtensionsCallback* _extensionsCallback;
};
typedef stdx::function<StatusWithMatchExpression(
const char* name, int type, const BSONObj& section)>
MatchExpressionParserGeoCallback;
extern MatchExpressionParserGeoCallback expressionParserGeoCallback;
}