- 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

2 files changed, 25 insertions, 14 deletions

diff --git a/lib/sqlalchemy/sql/base.py b/lib/sqlalchemy/sql/base.py
index 2d06109b9..0f6405309 100644
--- a/lib/sqlalchemy/sql/base.py
+++ b/lib/sqlalchemy/sql/base.py
@@ -449,10 +449,12 @@ class ColumnCollection(util.OrderedProperties):
 
     """
 
+    __slots__ = '_all_col_set', '_all_columns'
+
     def __init__(self, *columns):
         super(ColumnCollection, self).__init__()
-        self.__dict__['_all_col_set'] = util.column_set()
-        self.__dict__['_all_columns'] = []
+        object.__setattr__(self, '_all_col_set', util.column_set())
+        object.__setattr__(self, '_all_columns', [])
         for c in columns:
             self.add(c)
 
@@ -576,13 +578,14 @@ class ColumnCollection(util.OrderedProperties):
         return util.OrderedProperties.__contains__(self, other)
 
     def __getstate__(self):
-        return {'_data': self.__dict__['_data'],
-                '_all_columns': self.__dict__['_all_columns']}
+        return {'_data': self._data,
+                '_all_columns': self._all_columns}
 
     def __setstate__(self, state):
-        self.__dict__['_data'] = state['_data']
-        self.__dict__['_all_columns'] = state['_all_columns']
-        self.__dict__['_all_col_set'] = util.column_set(state['_all_columns'])
+        object.__setattr__(self, '_data', state['_data'])
+        object.__setattr__(self, '_all_columns', state['_all_columns'])
+        object.__setattr__(
+            self, '_all_col_set', util.column_set(state['_all_columns']))
 
     def contains_column(self, col):
         # this has to be done via set() membership
@@ -596,8 +599,8 @@ class ColumnCollection(util.OrderedProperties):
 class ImmutableColumnCollection(util.ImmutableProperties, ColumnCollection):
     def __init__(self, data, colset, all_columns):
         util.ImmutableProperties.__init__(self, data)
-        self.__dict__['_all_col_set'] = colset
-        self.__dict__['_all_columns'] = all_columns
+        object.__setattr__(self, '_all_col_set', colset)
+        object.__setattr__(self, '_all_columns', all_columns)
 
     extend = remove = util.ImmutableProperties._immutable
 
diff --git a/lib/sqlalchemy/sql/elements.py b/lib/sqlalchemy/sql/elements.py
index 445857b82..8df22b7a6 100644
--- a/lib/sqlalchemy/sql/elements.py
+++ b/lib/sqlalchemy/sql/elements.py
@@ -3387,7 +3387,7 @@ class ReleaseSavepointClause(_IdentifiedClause):
     __visit_name__ = 'release_savepoint'
 
 
-class quoted_name(util.text_type):
+class quoted_name(util.MemoizedSlots, util.text_type):
     """Represent a SQL identifier combined with quoting preferences.
 
     :class:`.quoted_name` is a Python unicode/str subclass which
@@ -3431,6 +3431,8 @@ class quoted_name(util.text_type):
 
     """
 
+    __slots__ = 'quote', 'lower', 'upper'
+
     def __new__(cls, value, quote):
         if value is None:
             return None
@@ -3450,15 +3452,13 @@ class quoted_name(util.text_type):
     def __reduce__(self):
         return quoted_name, (util.text_type(self), self.quote)
 
-    @util.memoized_instancemethod
-    def lower(self):
+    def _memoized_method_lower(self):
         if self.quote:
             return self
         else:
             return util.text_type(self).lower()
 
-    @util.memoized_instancemethod
-    def upper(self):
+    def _memoized_method_upper(self):
         if self.quote:
             return self
         else:
@@ -3475,6 +3475,8 @@ class _truncated_label(quoted_name):
     """A unicode subclass used to identify symbolic "
     "names that may require truncation."""
 
+    __slots__ = ()
+
     def __new__(cls, value, quote=None):
         quote = getattr(value, "quote", quote)
         # return super(_truncated_label, cls).__new__(cls, value, quote, True)
@@ -3531,6 +3533,7 @@ class conv(_truncated_label):
         :ref:`constraint_naming_conventions`
 
     """
+    __slots__ = ()
 
 
 class _defer_name(_truncated_label):
@@ -3538,6 +3541,8 @@ class _defer_name(_truncated_label):
     generation.
 
     """
+    __slots__ = ()
+
     def __new__(cls, value):
         if value is None:
             return _NONE_NAME
@@ -3552,6 +3557,7 @@ class _defer_name(_truncated_label):
 
 class _defer_none_name(_defer_name):
     """indicate a 'deferred' name that was ultimately the value None."""
+    __slots__ = ()
 
 _NONE_NAME = _defer_none_name("_unnamed_")
 
@@ -3566,6 +3572,8 @@ class _anonymous_label(_truncated_label):
     """A unicode subclass used to identify anonymously
     generated names."""
 
+    __slots__ = ()
+
     def __add__(self, other):
         return _anonymous_label(
             quoted_name(