Added a local cache to NavigationMapper - avoids some unpickling costs.

[philo.git] / philo / contrib / shipherd / models.py

diff --git a/philo/contrib/shipherd/models.py b/philo/contrib/shipherd/models.py
index c8579a2..3655e51 100644 (file)
--- a/philo/contrib/shipherd/models.py
+++ b/philo/contrib/shipherd/models.py
@@ -1,6 +1,9 @@
 #encoding: utf-8
 from UserDict import DictMixin
+from hashlib import sha1
 
+from django.contrib.sites.models import Site
+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
@@ -21,9 +24,15 @@ class NavigationMapper(object, DictMixin):
        """
        def __init__(self, node):
                self.node = node
+               self._cache = {}
        
        def __getitem__(self, 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):
@@ -39,41 +48,62 @@ 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').order_by('order')
+                       item_opts = NavigationItem._mptt_meta
+                       by_pk = {}
+                       tree_ids = []
+                       
+                       site_root_node = Site.objects.get_current().root_node
+                       
+                       for root in roots:
+                               by_pk[root.pk] = root
+                               tree_ids.append(getattr(root, item_opts.tree_id_attr))
+                               root._cached_children = []
+                               root.target_node.get_path(root=site_root_node)
+                               root.navigation = nav
+                       
+                       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)
+                               item.target_node.get_path(root=site_root_node)
+                       
+                       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 = 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).order_by('-node__%s' % opts.level_attr)
-               nav = navs[0]
-               roots = nav.roots.all()
-               item_opts = NavigationItem._mptt_meta
-               by_pk = {}
-               tree_ids = []
+               tree_id = getattr(node, opts.tree_id_attr)
+               parent_id = getattr(node, "%s_id" % opts.parent_attr)
                
-               for root in roots:
-                       by_pk[root.pk] = pk
-                       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).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)
-               
-               return roots
+               return sha1(unicode(left) + unicode(right) + unicode(tree_id) + unicode(parent_id) + unicode(node.pk) + unicode(key)).hexdigest()
 
 
 class Navigation(Entity):
@@ -142,13 +172,15 @@ class NavigationItem(TreeEntity, TargetURLModel):
                        # the same as the request path, check whether the target node is an ancestor
                        # of the requested node. If so, this is active unless the target node
                        # is the same as the ``host node`` for this navigation structure.
-                       try:
-                               host_node = self.get_root().navigation.node
-                       except AttributeError:
-                               pass
-                       else:
-                               if self.target_node != host_node and self.target_node.is_ancestor_of(request.node):
-                                       return True
+                       root = self
+                       
+                       # The common case will be cached items, whose parents are cached with them.
+                       while root.parent is not None:
+                               root = root.parent
+                       
+                       host_node_id = root.navigation.node_id
+                       if self.target_node.pk != host_node_id and self.target_node.is_ancestor_of(request.node):
+                               return True
                
                return False