diff options
Diffstat (limited to 'src/mongo/db/ops/modifier_inc.h')
| -rw-r--r-- | src/mongo/db/ops/modifier_inc.h | 115 |
1 files changed, 54 insertions, 61 deletions
diff --git a/src/mongo/db/ops/modifier_inc.h b/src/mongo/db/ops/modifier_inc.h index cfb7bbdf25d..17c76acf88f 100644 --- a/src/mongo/db/ops/modifier_inc.h +++ b/src/mongo/db/ops/modifier_inc.h @@ -37,64 +37,57 @@ namespace mongo { - class LogBuilder; - - class ModifierInc : public ModifierInterface { - MONGO_DISALLOW_COPYING(ModifierInc); - - public: - - // TODO: This is a shortcut to implementing $mul by hijacking $inc. In the near future, - // we should consider either pulling $mul into its own operator, or creating a general - // purpose "numeric binary op" operator. Potentially, that operator could also subsume - // $bit (thought there are some subtleties, like that $bit can have multiple - // operations, and doing so with arbirary math operations introduces potential - // associativity difficulties). At the very least, if this mechanism is retained, then - // this class should be renamed at some point away from ModifierInc. - enum ModifierIncMode { - MODE_INC, - MODE_MUL - }; - - ModifierInc(ModifierIncMode mode = MODE_INC); - virtual ~ModifierInc(); - - /** - * A 'modExpr' is a BSONElement {<fieldname>: <value>} coming from a $inc mod such as - * {$inc: {<fieldname: <value>}}. init() extracts the field name and the value to be - * assigned to it from 'modExpr'. It returns OK if successful or a status describing - * the error. - */ - virtual Status init(const BSONElement& modExpr, const Options& opts, - bool* positional = NULL); - - /** Evaluates the validity of applying $inc to the identified node, and computes - * effects, handling upcasting and overflow as necessary. - */ - virtual Status prepare(mutablebson::Element root, - StringData matchedField, - ExecInfo* execInfo); - - /** Updates the node passed in prepare with the results of the $inc */ - virtual Status apply() const; - - /** Converts the result of the $inc into an equivalent $set under logRoot */ - virtual Status log(LogBuilder* logBuilder) const; - - private: - const ModifierIncMode _mode; - - // 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; - - // Element of the $set expression. - SafeNum _val; - - struct PreparedState; - std::unique_ptr<PreparedState> _preparedState; - }; - -} // namespace mongo +class LogBuilder; + +class ModifierInc : public ModifierInterface { + MONGO_DISALLOW_COPYING(ModifierInc); + +public: + // TODO: This is a shortcut to implementing $mul by hijacking $inc. In the near future, + // we should consider either pulling $mul into its own operator, or creating a general + // purpose "numeric binary op" operator. Potentially, that operator could also subsume + // $bit (thought there are some subtleties, like that $bit can have multiple + // operations, and doing so with arbirary math operations introduces potential + // associativity difficulties). At the very least, if this mechanism is retained, then + // this class should be renamed at some point away from ModifierInc. + enum ModifierIncMode { MODE_INC, MODE_MUL }; + + ModifierInc(ModifierIncMode mode = MODE_INC); + virtual ~ModifierInc(); + + /** + * A 'modExpr' is a BSONElement {<fieldname>: <value>} coming from a $inc mod such as + * {$inc: {<fieldname: <value>}}. init() extracts the field name and the value to be + * assigned to it from 'modExpr'. It returns OK if successful or a status describing + * the error. + */ + virtual Status init(const BSONElement& modExpr, const Options& opts, bool* positional = NULL); + + /** Evaluates the validity of applying $inc to the identified node, and computes + * effects, handling upcasting and overflow as necessary. + */ + virtual Status prepare(mutablebson::Element root, StringData matchedField, ExecInfo* execInfo); + + /** Updates the node passed in prepare with the results of the $inc */ + virtual Status apply() const; + + /** Converts the result of the $inc into an equivalent $set under logRoot */ + virtual Status log(LogBuilder* logBuilder) const; + +private: + const ModifierIncMode _mode; + + // 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; + + // Element of the $set expression. + SafeNum _val; + + struct PreparedState; + std::unique_ptr<PreparedState> _preparedState; +}; + +} // namespace mongo |