Added django cache backend use on top of cacheless shipherd.

diff --git a/philo/contrib/shipherd/models.py b/philo/contrib/shipherd/models.py
index 9888378..9bba816 100644 (file)
--- a/philo/contrib/shipherd/models.py
+++ b/philo/contrib/shipherd/models.py
@@ -1,6 +1,8 @@
 #encoding: utf-8
 from UserDict import DictMixin
+from hashlib import sha1
 
+from django.core.cache import cache
 from django.core.exceptions import ValidationError
 from django.core.urlresolvers import NoReverseMatch
 from django.core.validators import RegexValidator, MinValueValidator
@@ -24,12 +26,13 @@ class NavigationMapper(object, DictMixin):
                self._cache = {}
        
        def __getitem__(self, key):
-               if key not in self._cache:
-                       try:
-                               self._cache[key] = Navigation.objects.get_for_node(self.node, key)
-                       except Navigation.DoesNotExist:
-                               self._cache[key] = None
-               return self._cache[key]
+               return Navigation.objects.get_for_node(self.node, key)
+               #if key not in self._cache:
+               #       try:
+               #               self._cache[key] = Navigation.objects.get_for_node(self.node, key)
+               #       except Navigation.DoesNotExist:
+               #               self._cache[key] = None
+               #return self._cache[key]
 
 
 def navigation(self):
@@ -45,41 +48,57 @@ class NavigationManager(models.Manager):
        use_for_related = True
        
        def get_for_node(self, node, key):
+               cache_key = self._get_cache_key(node, key)
+               cached = cache.get(cache_key)
+               
+               if cached is None:
+                       opts = Node._mptt_meta
+                       left = getattr(node, opts.left_attr)
+                       right = getattr(node, opts.right_attr)
+                       tree_id = getattr(node, opts.tree_id_attr)
+                       kwargs = {
+                               "node__%s__lte" % opts.left_attr: left,
+                               "node__%s__gte" % opts.right_attr: right,
+                               "node__%s" % opts.tree_id_attr: tree_id
+                       }
+                       navs = self.filter(key=key, **kwargs).select_related('node').order_by('-node__%s' % opts.level_attr)
+                       nav = navs[0]
+                       roots = nav.roots.all().select_related('target_node')
+                       item_opts = NavigationItem._mptt_meta
+                       by_pk = {}
+                       tree_ids = []
+                       
+                       for root in roots:
+                               by_pk[root.pk] = root
+                               tree_ids.append(getattr(root, item_opts.tree_id_attr))
+                               root._cached_children = []
+                       
+                       kwargs = {
+                               '%s__in' % item_opts.tree_id_attr: tree_ids,
+                               '%s__lt' % item_opts.level_attr: nav.depth,
+                               '%s__gt' % item_opts.level_attr: 0
+                       }
+                       items = NavigationItem.objects.filter(**kwargs).select_related('target_node').order_by('level', 'order')
+                       for item in items:
+                               by_pk[item.pk] = item
+                               item._cached_children = []
+                               parent_pk = getattr(item, '%s_id' % item_opts.parent_attr)
+                               item.parent = by_pk[parent_pk]
+                               item.parent._cached_children.append(item)
+                       
+                       cached = roots
+                       cache.set(cache_key, cached)
+               
+               return cached
+       
+       def _get_cache_key(self, node, key):
                opts = Node._mptt_meta
                left = getattr(node, opts.left_attr)
                right = getattr(node, opts.right_attr)
                tree_id = getattr(node, opts.tree_id_attr)
-               kwargs = {
-                       "node__%s__lte" % opts.left_attr: left,
-                       "node__%s__gte" % opts.right_attr: right,
-                       "node__%s" % opts.tree_id_attr: tree_id
-               }
-               navs = self.filter(key=key, **kwargs).select_related('node').order_by('-node__%s' % opts.level_attr)
-               nav = navs[0]
-               roots = nav.roots.all().select_related('target_node')
-               item_opts = NavigationItem._mptt_meta
-               by_pk = {}
-               tree_ids = []
-               
-               for root in roots:
-                       by_pk[root.pk] = root
-                       tree_ids.append(getattr(root, item_opts.tree_id_attr))
-                       root._cached_children = []
-               
-               kwargs = {
-                       '%s__in' % item_opts.tree_id_attr: tree_ids,
-                       '%s__lt' % item_opts.level_attr: nav.depth,
-                       '%s__gt' % item_opts.level_attr: 0
-               }
-               items = NavigationItem.objects.filter(**kwargs).select_related('target_node').order_by('level', 'order')
-               for item in items:
-                       by_pk[item.pk] = item
-                       item._cached_children = []
-                       parent_pk = getattr(item, '%s_id' % item_opts.parent_attr)
-                       item.parent = by_pk[parent_pk]
-                       item.parent._cached_children.append(item)
+               parent_id = getattr(node, "%s_id" % opts.parent_attr)
                
-               return roots
+               return sha1(unicode(left) + unicode(right) + unicode(tree_id) + unicode(parent_id) + unicode(node.pk) + unicode(key)).hexdigest()
 
 
 class Navigation(Entity):