diff options
Diffstat (limited to 'src/mongo/db/ops/modifier_push.h')
| -rw-r--r-- | src/mongo/db/ops/modifier_push.h | 182 |
1 files changed, 88 insertions, 94 deletions
diff --git a/src/mongo/db/ops/modifier_push.h b/src/mongo/db/ops/modifier_push.h index 708c6431d97..df9c4b65db9 100644 --- a/src/mongo/db/ops/modifier_push.h +++ b/src/mongo/db/ops/modifier_push.h @@ -39,97 +39,91 @@ namespace mongo { - class LogBuilder; - - class ModifierPush : public ModifierInterface { - MONGO_DISALLOW_COPYING(ModifierPush); - - public: - - enum ModifierPushMode { PUSH_NORMAL, PUSH_ALL }; - explicit ModifierPush(ModifierPushMode mode= PUSH_NORMAL); - - // - // Modifier interface implementation - // - - virtual ~ModifierPush(); - - /** - * A 'modExpr' here is a BSONElement {<fieldname>: <each clause>, <slice clause>, <sort - * clause>} coming from a $push mod such as {$set: {x: $each[{a:1}], $slice:3, - * $sort{b:1}}}. init() extracts and validates the field name and the clauses. It - * returns OK if successful or a status describing the error. - * - * There are currently a few restrictions concerning the clauses (but all can be - * lifted): - * + $slice can be negative only (ie, slicing from the recent end) - * + $sort requires $slice to be present - * + $sort can only sort objects (as opposed to basic types), so it only takes - * object as patterns - * + Because of the previous, $sort requires that the array being pushed to be made - * of objects - */ - virtual Status init(const BSONElement& modExpr, const Options& opts, - bool* positional = NULL); - - /** - * Locates the array to be pushed into in the 'root', if it exists, and fills in - * execInfo accordingly. Returns true if $push would succeed in 'root', otherwise - * return a status describing the error. - * - * Note that a $push is never in-place. The cost of checking if it is a no-op makes it - * so that we don't do such check either. As such, execInfo is always filled with - * 'false' for those two options. - */ - virtual Status prepare(mutablebson::Element root, - StringData matchedField, - ExecInfo* execInfo); - - /** - * Pushes the array into the prepared position and "sort/slice"s the resulting array - * according to that call's instructions. - */ - virtual Status apply() const; - - /** - * $push currently logs the entire resulting array as a $set. - * - * TODO Log a positional $set in the array, whenever possible. - */ - virtual Status log(LogBuilder* logBuilder) const; - - private: - - // Access to each component of fieldName that's the target of this mod. - FieldRef _fieldRef; - - // 0 or index for $-positional in _fieldRef. - size_t _posDollar; - - // Clauses for the $push that are filled when the $each variation of the command is used. - bool _eachMode; - BSONElement _eachElem; - bool _slicePresent; - int64_t _slice; - bool _sortPresent; - size_t _startPosition; - - PatternElementCmp _sort; - - // Whether this mod is supposed to be parsed as a $pushAll. - const ModifierPushMode _pushMode; - - // Simple (old style) push value when the $each variation of the command is not - // used. The _eachMode flag would be off if we're this mode. - BSONElement _val; - - // The instance of the field in the provided doc. This state is valid after a - // prepare() was issued and until a log() is issued. The document this mod is - // being prepared against must be live throughout all the calls. - struct PreparedState; - std::unique_ptr<PreparedState> _preparedState; - - }; - -} // namespace mongo +class LogBuilder; + +class ModifierPush : public ModifierInterface { + MONGO_DISALLOW_COPYING(ModifierPush); + +public: + enum ModifierPushMode { PUSH_NORMAL, PUSH_ALL }; + explicit ModifierPush(ModifierPushMode mode = PUSH_NORMAL); + + // + // Modifier interface implementation + // + + virtual ~ModifierPush(); + + /** + * A 'modExpr' here is a BSONElement {<fieldname>: <each clause>, <slice clause>, <sort + * clause>} coming from a $push mod such as {$set: {x: $each[{a:1}], $slice:3, + * $sort{b:1}}}. init() extracts and validates the field name and the clauses. It + * returns OK if successful or a status describing the error. + * + * There are currently a few restrictions concerning the clauses (but all can be + * lifted): + * + $slice can be negative only (ie, slicing from the recent end) + * + $sort requires $slice to be present + * + $sort can only sort objects (as opposed to basic types), so it only takes + * object as patterns + * + Because of the previous, $sort requires that the array being pushed to be made + * of objects + */ + virtual Status init(const BSONElement& modExpr, const Options& opts, bool* positional = NULL); + + /** + * Locates the array to be pushed into in the 'root', if it exists, and fills in + * execInfo accordingly. Returns true if $push would succeed in 'root', otherwise + * return a status describing the error. + * + * Note that a $push is never in-place. The cost of checking if it is a no-op makes it + * so that we don't do such check either. As such, execInfo is always filled with + * 'false' for those two options. + */ + virtual Status prepare(mutablebson::Element root, StringData matchedField, ExecInfo* execInfo); + + /** + * Pushes the array into the prepared position and "sort/slice"s the resulting array + * according to that call's instructions. + */ + virtual Status apply() const; + + /** + * $push currently logs the entire resulting array as a $set. + * + * TODO Log a positional $set in the array, whenever possible. + */ + virtual Status log(LogBuilder* logBuilder) const; + +private: + // Access to each component of fieldName that's the target of this mod. + FieldRef _fieldRef; + + // 0 or index for $-positional in _fieldRef. + size_t _posDollar; + + // Clauses for the $push that are filled when the $each variation of the command is used. + bool _eachMode; + BSONElement _eachElem; + bool _slicePresent; + int64_t _slice; + bool _sortPresent; + size_t _startPosition; + + PatternElementCmp _sort; + + // Whether this mod is supposed to be parsed as a $pushAll. + const ModifierPushMode _pushMode; + + // Simple (old style) push value when the $each variation of the command is not + // used. The _eachMode flag would be off if we're this mode. + BSONElement _val; + + // The instance of the field in the provided doc. This state is valid after a + // prepare() was issued and until a log() is issued. The document this mod is + // being prepared against must be live throughout all the calls. + struct PreparedState; + std::unique_ptr<PreparedState> _preparedState; +}; + +} // namespace mongo |