diff options
Diffstat (limited to 'src/mongo/db/matcher/expression_parser.h')
| -rw-r--r-- | src/mongo/db/matcher/expression_parser.h | 84 |
1 files changed, 65 insertions, 19 deletions
diff --git a/src/mongo/db/matcher/expression_parser.h b/src/mongo/db/matcher/expression_parser.h index b4c45e6cb81..ae2c2a991ac 100644 --- a/src/mongo/db/matcher/expression_parser.h +++ b/src/mongo/db/matcher/expression_parser.h @@ -46,16 +46,37 @@ namespace mongo { public: /** + * In general, expression parsing and matching should not require context, but the $where + * clause is an exception in that it needs to read the sys.js collection. + * + * The default behaviour is to return an error status that $where context is not present. + * + * Do not use this class to pass-in generic context as it should only be used for $where. + */ + class WhereCallback { + public: + virtual StatusWithMatchExpression parseWhere(const BSONElement& where) const; + + virtual ~WhereCallback() { } + }; + + /** * caller has to maintain ownership obj * the tree has views (BSONElement) into obj */ - static StatusWithMatchExpression parse( const BSONObj& obj ) { + static StatusWithMatchExpression parse(const BSONObj& obj, + const WhereCallback& whereCallback = WhereCallback()) { // The 0 initializes the match expression tree depth. - return _parse( obj, 0 ); + return MatchExpressionParser(&whereCallback)._parse(obj, 0); } private: + explicit MatchExpressionParser(const WhereCallback* whereCallback) + : _whereCallback(whereCallback) { + + } + /** * 5 = false * { a : 5 } = false @@ -66,7 +87,7 @@ namespace mongo { * { $id : "x" } = false (if incomplete DBRef is allowed) * { $db : "mydb" } = false (if incomplete DBRef is allowed) */ - static bool _isExpressionDocument( const BSONElement& e, bool allowIncompleteDBRef ); + bool _isExpressionDocument( const BSONElement& e, bool allowIncompleteDBRef ); /** * { $ref: "s", $id: "x" } = true @@ -74,7 +95,7 @@ namespace mongo { * { $id : "x" } = true (if incomplete DBRef is allowed) * { $db : "x" } = true (if incomplete DBRef is allowed) */ - static bool _isDBRefDocument( const BSONObj& obj, bool allowIncompleteDBRef ); + bool _isDBRefDocument( const BSONObj& obj, bool allowIncompleteDBRef ); /** * Parse 'obj' and return either a MatchExpression or an error. @@ -83,14 +104,14 @@ namespace mongo { * function. Used in order to apply special logic at the top-level and to return an * error if the tree exceeds the maximum allowed depth. */ - static StatusWithMatchExpression _parse( const BSONObj& obj, int level ); + StatusWithMatchExpression _parse( const BSONObj& obj, int level ); /** * parses a field in a sub expression * if the query is { x : { $gt : 5, $lt : 8 } } * e is { $gt : 5, $lt : 8 } */ - static Status _parseSub( const char* name, + Status _parseSub( const char* name, const BSONObj& obj, AndMatchExpression* root, int level ); @@ -100,57 +121,82 @@ namespace mongo { * if the query is { x : { $gt : 5, $lt : 8 } } * e is $gt : 5 */ - static StatusWithMatchExpression _parseSubField( const BSONObj& context, + StatusWithMatchExpression _parseSubField( const BSONObj& context, const AndMatchExpression* andSoFar, const char* name, const BSONElement& e, int level ); - static StatusWithMatchExpression _parseComparison( const char* name, + StatusWithMatchExpression _parseComparison( const char* name, ComparisonMatchExpression* cmp, const BSONElement& e ); - static StatusWithMatchExpression _parseMOD( const char* name, + StatusWithMatchExpression _parseMOD( const char* name, const BSONElement& e ); - static StatusWithMatchExpression _parseRegexElement( const char* name, + StatusWithMatchExpression _parseRegexElement( const char* name, const BSONElement& e ); - static StatusWithMatchExpression _parseRegexDocument( const char* name, + StatusWithMatchExpression _parseRegexDocument( const char* name, const BSONObj& doc ); - static Status _parseArrayFilterEntries( ArrayFilterEntries* entries, + Status _parseArrayFilterEntries( ArrayFilterEntries* entries, const BSONObj& theArray ); // arrays - static StatusWithMatchExpression _parseElemMatch( const char* name, + StatusWithMatchExpression _parseElemMatch( const char* name, const BSONElement& e, int level ); - static StatusWithMatchExpression _parseAll( const char* name, + StatusWithMatchExpression _parseAll( const char* name, const BSONElement& e, int level ); // tree - static Status _parseTreeList( const BSONObj& arr, ListOfMatchExpression* out, int level ); + Status _parseTreeList( const BSONObj& arr, ListOfMatchExpression* out, int level ); - static StatusWithMatchExpression _parseNot( const char* name, + StatusWithMatchExpression _parseNot( const char* name, const BSONElement& e, int level ); // The maximum allowed depth of a query tree. Just to guard against stack overflow. static const int kMaximumTreeDepth; + + // Performs parsing for the $where clause. We do not own this pointer - it has to live + // as long as the parser is active. + const WhereCallback* _whereCallback; + }; + + /** + * This implementation is used for the server-side code. + */ + class WhereCallbackReal : public MatchExpressionParser::WhereCallback { + public: + WhereCallbackReal(const StringData& dbName); + + virtual StatusWithMatchExpression parseWhere(const BSONElement& where) const; + + private: + const StringData _dbName; }; + /** + * This is just a pass-through implementation, used by sharding only. + */ + class WhereCallbackNoop : public MatchExpressionParser::WhereCallback { + public: + WhereCallbackNoop(); + + virtual StatusWithMatchExpression parseWhere(const BSONElement& where) const; + }; + + typedef boost::function<StatusWithMatchExpression(const char* name, int type, const BSONObj& section)> MatchExpressionParserGeoCallback; extern MatchExpressionParserGeoCallback expressionParserGeoCallback; - typedef boost::function<StatusWithMatchExpression(const BSONElement& where)> MatchExpressionParserWhereCallback; - extern MatchExpressionParserWhereCallback expressionParserWhereCallback; - typedef boost::function<StatusWithMatchExpression(const BSONObj& queryObj)> MatchExpressionParserTextCallback; extern MatchExpressionParserTextCallback expressionParserTextCallback; |