Added memoization (optional but enabled by default) to TreeEntity.get_path.

diff --git a/philo/models/base.py b/philo/models/base.py
index 2f798ae..d1dc38a 100644 (file)
--- a/philo/models/base.py
+++ b/philo/models/base.py
@@ -458,11 +458,12 @@ class TreeEntity(Entity, MPTTModel):
        objects = TreeEntityManager()
        parent = models.ForeignKey('self', related_name='children', null=True, blank=True)
        
-       def get_path(self, root=None, pathsep='/', field='slug'):
+       def get_path(self, root=None, pathsep='/', field='pk', memoize=True):
                """
                :param root: Only return the path since this object.
                :param pathsep: The path separator to use when constructing an instance's path
                :param field: The field to pull path information from for each ancestor.
+               :param memoize: Whether to use memoized results. Since, in most cases, the ancestors of a TreeEntity will not change over the course of an instance's lifetime, this defaults to ``True``.
                :returns: A string representation of an object's path.
                
                """
@@ -476,12 +477,26 @@ class TreeEntity(Entity, MPTTModel):
                if root is not None and not self.is_descendant_of(root):
                        raise AncestorDoesNotExist(root)
                
+               if memoize:
+                       memo_args = (getattr(self, "%s_id" % self._mptt_meta.parent_attr), getattr(root, 'pk', None), pathsep, getattr(self, field, '?'))
+                       try:
+                               return self._path_memo[memo_args]
+                       except AttributeError:
+                               self._path_memo = {}
+                       except KeyError:
+                               pass
+               
                qs = self.get_ancestors(include_self=True)
                
                if root is not None:
                        qs = qs.filter(**{'%s__gt' % self._mptt_meta.level_attr: root.get_level()})
                
-               return pathsep.join([getattr(parent, field, '?') for parent in qs])
+               path = pathsep.join([getattr(parent, field, '?') for parent in qs])
+               
+               if memoize:
+                       self._path_memo[memo_args] = path
+               
+               return path
        path = property(get_path)
        
        def get_attribute_mapper(self, mapper=None):
@@ -522,8 +537,8 @@ class SlugTreeEntity(TreeEntity):
        objects = SlugTreeEntityManager()
        slug = models.SlugField(max_length=255)
        
-       def get_path(self, root=None, pathsep='/', field='slug'):
-               return super(SlugTreeEntity, self).get_path(root, pathsep, field)
+       def get_path(self, root=None, pathsep='/', field='slug', memoize=True):
+               return super(SlugTreeEntity, self).get_path(root, pathsep, field, memoize)
        path = property(get_path)
        
        def clean(self):