Ticket #13812: 13812_faster_context_using_deque.diff

context.py

@@ +1 @@
+import collections
+
 from django.core.exceptions import ImproperlyConfigured
 from django.utils.importlib import import_module
 
@@ -15 +17 @@
 class BaseContext(object):
     def __init__(self, dict_=None):
         dict_ = dict_ or {}
-        self.dicts = [dict_]
+        self.dicts = collections.deque((dict_,))
 
     def __repr__(self):
         return repr(self.dicts)
 
     def __iter__(self):
-        for d in reversed(self.dicts):
+        for d in self.dicts:
             yield d
 
     def push(self):
         d = {}
-        self.dicts.append(d)
+        self.dicts.appendleft(d)
         return d
 
     def pop(self):
         if len(self.dicts) == 1:
             raise ContextPopException
-        return self.dicts.pop()
+        return self.dicts.popleft()
 
     def __setitem__(self, key, value):
         "Set a variable in the current context"
-        self.dicts[-1][key] = value
+        self.dicts[0][key] = value
 
     def __getitem__(self, key):
         "Get a variable's value, starting at the current context and going upward"
-        for d in reversed(self.dicts):
+        for d in self.dicts:
             if key in d:
                 return d[key]
         raise KeyError(key)
 
     def __delitem__(self, key):
         "Delete a variable from the current context"
-        del self.dicts[-1][key]
+        del self.dicts[0][key]
 
     def has_key(self, key):
         for d in self.dicts:
@@ -59 +61 @@
         return self.has_key(key)
 
     def get(self, key, otherwise=None):
-        for d in reversed(self.dicts):
+        for d in self.dicts:
             if key in d:
                 return d[key]
         return otherwise
@@ -76 +78 @@
         "Like dict.update(). Pushes an entire dictionary's keys and values onto the context."
         if not hasattr(other_dict, '__getitem__'):
             raise TypeError('other_dict must be a mapping (dictionary-like) object.')
-        self.dicts.append(other_dict)
+        self.dicts.appendleft(other_dict)
         return other_dict
 
 class RenderContext(BaseContext):
@@ -95 +97 @@
     template context.
     """
     def __iter__(self):
-        for d in self.dicts[-1]:
+        for d in self.dicts[0]:
             yield d
 
     def has_key(self, key):
-        return key in self.dicts[-1]
+        return key in self.dicts[0]
 
     def get(self, key, otherwise=None):
-        d = self.dicts[-1]
+        d = self.dicts[0]
         if key in d:
             return d[key]
         return otherwise