- add MemoizedSlots, a generalized solution to using __getattr__

for memoization on a class that uses slots.
- apply many more __slots__.  mem use for nova now at 46% savings

1 files changed, 43 insertions, 8 deletions

diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py
index 68b86268c..346e2412e 100644
--- a/lib/sqlalchemy/orm/interfaces.py
+++ b/lib/sqlalchemy/orm/interfaces.py
@@ -24,7 +24,8 @@ from .. import util
 from ..sql import operators
 from .base import (ONETOMANY, MANYTOONE, MANYTOMANY,
                    EXT_CONTINUE, EXT_STOP, NOT_EXTENSION)
-from .base import InspectionAttr, _MappedAttribute
+from .base import (InspectionAttr, InspectionAttr,
+    InspectionAttrInfo, _MappedAttribute)
 import collections
 
 # imported later
@@ -48,7 +49,7 @@ __all__ = (
 )
 
 
-class MapperProperty(_MappedAttribute, InspectionAttr):
+class MapperProperty(_MappedAttribute, InspectionAttr, util.MemoizedSlots):
     """Manage the relationship of a ``Mapper`` to a single class
     attribute, as well as that attribute as it appears on individual
     instances of the class, including attribute instrumentation,
@@ -63,6 +64,11 @@ class MapperProperty(_MappedAttribute, InspectionAttr):
 
     """
 
+    __slots__ = (
+        '_configure_started', '_configure_finished', 'parent', 'key',
+        'info'
+    )
+
     cascade = frozenset()
     """The set of 'cascade' attribute names.
 
@@ -78,6 +84,32 @@ class MapperProperty(_MappedAttribute, InspectionAttr):
 
     """
 
+    def _memoized_attr_info(self):
+        """Info dictionary associated with the object, allowing user-defined
+        data to be associated with this :class:`.InspectionAttr`.
+
+        The dictionary is generated when first accessed.  Alternatively,
+        it can be specified as a constructor argument to the
+        :func:`.column_property`, :func:`.relationship`, or :func:`.composite`
+        functions.
+
+        .. versionadded:: 0.8  Added support for .info to all
+           :class:`.MapperProperty` subclasses.
+
+        .. versionchanged:: 1.0.0 :attr:`.InspectionAttr.info` moved
+           from :class:`.MapperProperty` so that it can apply to a wider
+           variety of ORM and extension constructs.
+
+        .. seealso::
+
+            :attr:`.QueryableAttribute.info`
+
+            :attr:`.SchemaItem.info`
+
+        """
+        return {}
+
+
     def setup(self, context, entity, path, adapter, **kwargs):
         """Called by Query for the purposes of constructing a SQL statement.
 
@@ -139,8 +171,9 @@ class MapperProperty(_MappedAttribute, InspectionAttr):
 
         """
 
-    _configure_started = False
-    _configure_finished = False
+    def __init__(self):
+        self._configure_started = False
+        self._configure_finished = False
 
     def init(self):
         """Called after all mappers are created to assemble
@@ -422,6 +455,8 @@ class StrategizedProperty(MapperProperty):
 
     """
 
+    __slots__ = '_strategies', 'strategy'
+
     strategy_wildcard_key = None
 
     def _get_context_loader(self, context, path):
@@ -485,14 +520,14 @@ class StrategizedProperty(MapperProperty):
                 not mapper.class_manager._attr_has_impl(self.key):
             self.strategy.init_class_attribute(mapper)
 
-    _strategies = collections.defaultdict(dict)
+    _all_strategies = collections.defaultdict(dict)
 
     @classmethod
     def strategy_for(cls, **kw):
         def decorate(dec_cls):
             dec_cls._strategy_keys = []
             key = tuple(sorted(kw.items()))
-            cls._strategies[cls][key] = dec_cls
+            cls._all_strategies[cls][key] = dec_cls
             dec_cls._strategy_keys.append(key)
             return dec_cls
         return decorate
@@ -500,8 +535,8 @@ class StrategizedProperty(MapperProperty):
     @classmethod
     def _strategy_lookup(cls, *key):
         for prop_cls in cls.__mro__:
-            if prop_cls in cls._strategies:
-                strategies = cls._strategies[prop_cls]
+            if prop_cls in cls._all_strategies:
+                strategies = cls._all_strategies[prop_cls]
                 try:
                     return strategies[key]
                 except KeyError: