callcount reduction

3 files changed, 30 insertions, 23 deletions

diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py
index 28ab383c3..d50aea83a 100644
--- a/lib/sqlalchemy/orm/interfaces.py
+++ b/lib/sqlalchemy/orm/interfaces.py
@@ -296,9 +296,9 @@ class StrategizedProperty(MapperProperty):
     """
     
     def _get_context_strategy(self, context, path):
-        cls = context.attributes.get(('loaderstrategy',
-                _reduce_path(path)), None)
-        if cls:
+        key = ('loaderstrategy', _reduce_path(path))
+        if key in context.attributes:
+            cls = context.attributes[key]
             try:
                 return self._strategies[cls]
             except KeyError:
@@ -546,9 +546,9 @@ def _reduce_path(path):
     
     """
     return tuple([i % 2 != 0 and 
-                    path[i] or 
-                    getattr(path[i], 'base_mapper', path[i]) 
-                    for i in xrange(len(path))])
+                    element or 
+                    getattr(element, 'base_mapper', element) 
+                    for i, element in enumerate(path)])
 
 class LoaderStrategy(object):
     """Describe the loading behavior of a StrategizedProperty object.
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index 60ca33b93..b8c06cb08 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -1090,12 +1090,12 @@ def _clause_element_as_expr(element):
         return element
         
 def _literal_as_column(element):
-    if hasattr(element, '__clause_element__'):
+    if isinstance(element, Visitable):
+        return element
+    elif hasattr(element, '__clause_element__'):
         return element.__clause_element__()
-    elif not isinstance(element, Visitable):
-        return literal_column(str(element))
     else:
-        return element
+        return literal_column(str(element))
 
 def _literal_as_binds(element, name=None, type_=None):
     if hasattr(element, '__clause_element__'):
@@ -3557,7 +3557,14 @@ class ColumnClause(_Immutable, ColumnElement):
         self.table = selectable
         self.type = sqltypes.to_instance(type_)
         self.is_literal = is_literal
-
+    
+    @util.memoized_property
+    def _from_objects(self):
+        if self.table is not None:
+            return [self.table]
+        else:
+            return []
+        
     @util.memoized_property
     def description(self):
         # Py3K
@@ -3601,12 +3608,6 @@ class ColumnClause(_Immutable, ColumnElement):
         else:
             return super(ColumnClause, self).label(name)
 
-    @property
-    def _from_objects(self):
-        if self.table is not None:
-            return [self.table]
-        else:
-            return []
 
     def _bind_param(self, operator, obj):
         return _BindParamClause(self.name, obj,
@@ -3712,6 +3713,9 @@ class TableClause(_Immutable, FromClause):
 class _SelectBase(Executable, FromClause):
     """Base class for :class:`Select` and ``CompoundSelects``."""
 
+    _order_by_clause = ClauseList()
+    _group_by_clause = ClauseList()
+    
     def __init__(self,
             use_labels=False,
             for_update=False,
@@ -3733,9 +3737,11 @@ class _SelectBase(Executable, FromClause):
         self._limit = limit
         self._offset = offset
         self._bind = bind
-
-        self._order_by_clause = ClauseList(*util.to_list(order_by) or [])
-        self._group_by_clause = ClauseList(*util.to_list(group_by) or [])
+        
+        if order_by is not None:
+            self._order_by_clause = ClauseList(*util.to_list(order_by))
+        if group_by is not None:
+            self._group_by_clause = ClauseList(*util.to_list(group_by))
     
     def as_scalar(self):
         """return a 'scalar' representation of this selectable, which can be
diff --git a/lib/sqlalchemy/util/_collections.py b/lib/sqlalchemy/util/_collections.py
index 57ce02a1e..4ab52c3d6 100644
--- a/lib/sqlalchemy/util/_collections.py
+++ b/lib/sqlalchemy/util/_collections.py
@@ -270,9 +270,10 @@ class OrderedSet(set):
     __str__ = __repr__
 
     def update(self, iterable):
-        add = self.add
-        for i in iterable:
-            add(i)
+        for e in iterable:
+            if e not in self:
+                self._list.append(e)
+                set.add(self, e)
         return self
 
     __ior__ = update