diff options
Diffstat (limited to 'src/mongo/db/projection.h')
| -rw-r--r-- | src/mongo/db/projection.h | 225 |
1 files changed, 112 insertions, 113 deletions
diff --git a/src/mongo/db/projection.h b/src/mongo/db/projection.h index b9424cec3e9..de495ce327f 100644 --- a/src/mongo/db/projection.h +++ b/src/mongo/db/projection.h @@ -39,136 +39,135 @@ namespace mongo { - /** - * given a document and a projection specification - * can transform the document - * currently supports specifying which fields and $slice - */ - class Projection { +/** + * given a document and a projection specification + * can transform the document + * currently supports specifying which fields and $slice + */ +class Projection { +public: + class KeyOnly { public: + KeyOnly() : _stringSize(0) {} - class KeyOnly { - public: - - KeyOnly() : _stringSize(0) {} + BSONObj hydrate(const BSONObj& key) const; - BSONObj hydrate( const BSONObj& key ) const; - - void addNo() { _add( false , "" ); } - void addYes( const std::string& name ) { _add( true , name ); } - - private: + void addNo() { + _add(false, ""); + } + void addYes(const std::string& name) { + _add(true, name); + } - void _add( bool b , const std::string& name ) { - _include.push_back( b ); - _names.push_back( name ); - _stringSize += name.size(); - } + private: + void _add(bool b, const std::string& name) { + _include.push_back(b); + _names.push_back(name); + _stringSize += name.size(); + } - std::vector<bool> _include; // one entry per field in key. true iff should be in output - std::vector<std::string> _names; // name of field since key doesn't have names + std::vector<bool> _include; // one entry per field in key. true iff should be in output + std::vector<std::string> _names; // name of field since key doesn't have names - int _stringSize; - }; + int _stringSize; + }; - enum ArrayOpType { - ARRAY_OP_NORMAL = 0, - ARRAY_OP_ELEM_MATCH, - ARRAY_OP_POSITIONAL - }; + enum ArrayOpType { ARRAY_OP_NORMAL = 0, ARRAY_OP_ELEM_MATCH, ARRAY_OP_POSITIONAL }; - Projection() : - _include(true) , - _special(false) , - _includeID(true) , - _skip(0) , - _limit(-1) , - _arrayOpType(ARRAY_OP_NORMAL), - _hasNonSimple(false) { - } + Projection() + : _include(true), + _special(false), + _includeID(true), + _skip(0), + _limit(-1), + _arrayOpType(ARRAY_OP_NORMAL), + _hasNonSimple(false) {} - /** - * called once per lifetime - * e.g. { "x" : 1 , "a.y" : 1 } - */ - void init(const BSONObj& spec, const MatchExpressionParser::WhereCallback& whereCallback); - - /** - * @return the spec init was called with - */ - BSONObj getSpec() const { return _source; } - - /** - * transforms in according to spec - */ - BSONObj transform( const BSONObj& in, const MatchDetails* details = NULL ) const; - - - /** - * transforms in according to spec - */ - void transform( const BSONObj& in , BSONObjBuilder& b, const MatchDetails* details = NULL ) const; - - - /** - * @return if the keyPattern has all the information needed to return then - * return a new KeyOnly otherwise null - * NOTE: a key may have modified the actual data - * which has to be handled above this (arrays, geo) - */ - KeyOnly* checkKey( const BSONObj& keyPattern ) const; - - bool includeID() const { return _includeID; } - - /** - * get the type of array operator for the projection - * @return ARRAY_OP_NORMAL if no array projection modifier, - * ARRAY_OP_ELEM_MATCH if one or more $elemMatch specifier, - * ARRAY_OP_POSITIONAL if one '.$' projection specified - */ - ArrayOpType getArrayOpType() const; - - /** - * Validate the given query satisfies this projection's positional operator. - * NOTE: this function is only used to validate projections with a positional operator. - * @param query User-supplied query specifier - * @return Field name if found, empty std::string otherwise. - */ - void validateQuery( const BSONObj query ) const; + /** + * called once per lifetime + * e.g. { "x" : 1 , "a.y" : 1 } + */ + void init(const BSONObj& spec, const MatchExpressionParser::WhereCallback& whereCallback); - private: + /** + * @return the spec init was called with + */ + BSONObj getSpec() const { + return _source; + } - /** - * appends e to b if user wants it - * will descend into e if needed - */ - void append( BSONObjBuilder& b , const BSONElement& e, const MatchDetails* details = NULL, - const ArrayOpType arrayOpType = ARRAY_OP_NORMAL ) const; + /** + * transforms in according to spec + */ + BSONObj transform(const BSONObj& in, const MatchDetails* details = NULL) const; - void add( const std::string& field, bool include ); - void add( const std::string& field, int skip, int limit ); - void appendArray( BSONObjBuilder& b , const BSONObj& a , bool nested=false) const; - bool _include; // true if default at this level is to include - bool _special; // true if this level can't be skipped or included without recursing + /** + * transforms in according to spec + */ + void transform(const BSONObj& in, BSONObjBuilder& b, const MatchDetails* details = NULL) const; - //TODO: benchmark std::vector<pair> vs map - typedef StringMap<boost::shared_ptr<Projection> > FieldMap; - FieldMap _fields; - BSONObj _source; - bool _includeID; - // used for $slice operator - int _skip; - int _limit; + /** + * @return if the keyPattern has all the information needed to return then + * return a new KeyOnly otherwise null + * NOTE: a key may have modified the actual data + * which has to be handled above this (arrays, geo) + */ + KeyOnly* checkKey(const BSONObj& keyPattern) const; - // used for $elemMatch and positional operator ($) - typedef StringMap<boost::shared_ptr<Matcher> > Matchers; - Matchers _matchers; - ArrayOpType _arrayOpType; + bool includeID() const { + return _includeID; + } - bool _hasNonSimple; - }; + /** + * get the type of array operator for the projection + * @return ARRAY_OP_NORMAL if no array projection modifier, + * ARRAY_OP_ELEM_MATCH if one or more $elemMatch specifier, + * ARRAY_OP_POSITIONAL if one '.$' projection specified + */ + ArrayOpType getArrayOpType() const; + /** + * Validate the given query satisfies this projection's positional operator. + * NOTE: this function is only used to validate projections with a positional operator. + * @param query User-supplied query specifier + * @return Field name if found, empty std::string otherwise. + */ + void validateQuery(const BSONObj query) const; +private: + /** + * appends e to b if user wants it + * will descend into e if needed + */ + void append(BSONObjBuilder& b, + const BSONElement& e, + const MatchDetails* details = NULL, + const ArrayOpType arrayOpType = ARRAY_OP_NORMAL) const; + + void add(const std::string& field, bool include); + void add(const std::string& field, int skip, int limit); + void appendArray(BSONObjBuilder& b, const BSONObj& a, bool nested = false) const; + + bool _include; // true if default at this level is to include + bool _special; // true if this level can't be skipped or included without recursing + + // TODO: benchmark std::vector<pair> vs map + typedef StringMap<boost::shared_ptr<Projection>> FieldMap; + FieldMap _fields; + BSONObj _source; + bool _includeID; + + // used for $slice operator + int _skip; + int _limit; + + // used for $elemMatch and positional operator ($) + typedef StringMap<boost::shared_ptr<Matcher>> Matchers; + Matchers _matchers; + ArrayOpType _arrayOpType; + + bool _hasNonSimple; +}; } |