Merged cowell back into core.

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

diff --git a/contrib/shipherd/models.py b/contrib/shipherd/models.py
index 72bd775..dee16e9 100644 (file)
--- a/contrib/shipherd/models.py
+++ b/contrib/shipherd/models.py
@@ -1,139 +1,225 @@
 #encoding: utf-8
 from django.core.exceptions import ValidationError
 from django.core.urlresolvers import NoReverseMatch
 #encoding: utf-8
 from django.core.exceptions import ValidationError
 from django.core.urlresolvers import NoReverseMatch

+from django.core.validators import RegexValidator, MinValueValidator

 from django.db import models
 from django.forms.models import model_to_dict
 from django.db import models
 from django.forms.models import model_to_dict

-from philo.models import TreeEntity, JSONField, Node, TreeManager
+from philo.models import TreeEntity, JSONField, Node, TreeManager, Entity

 from philo.validators import RedirectValidator
 from philo.validators import RedirectValidator

+from UserDict import DictMixin

 
 
 DEFAULT_NAVIGATION_DEPTH = 3
 
 
 
 
 DEFAULT_NAVIGATION_DEPTH = 3
 
 

-class NavigationQuerySet(models.query.QuerySet):
+class NavigationQuerySetMapper(object, DictMixin):
+       """This class exists to prevent setting of items in the navigation cache through node.navigation."""
+       def __init__(self, node):
+               self.node = node
+       
+       def __getitem__(self, key):
+               return Navigation.objects.get_cache_for(self.node)[key]['root_items']
+       
+       def keys(self):
+               return Navigation.objects.get_cache_for(self.node).keys()
+
+
+def navigation(self):
+       if not hasattr(self, '_navigation'):
+               self._navigation = NavigationQuerySetMapper(self)
+       return self._navigation
+
+
+Node.navigation = property(navigation)
+
+
+class NavigationCacheQuerySet(models.query.QuerySet):

        """
        """

-       This subclass is necessary to trigger cache clearing for Navigation when a mass update
-       or deletion is performed. For now, either action will trigger a clearing of the entire
-       navigation cache, since there's no convenient way to iterate over the changed or
-       deleted instances.
+       This subclass will trigger general cache clearing for Navigation.objects when a mass
+       update or deletion is performed. As there is no convenient way to iterate over the
+       changed or deleted instances, there's no way to be more precise about what gets cleared.

        """
        def update(self, *args, **kwargs):
        """
        def update(self, *args, **kwargs):

-               super(NavigationQuerySet, self).update(*args, **kwargs)
+               super(NavigationCacheQuerySet, self).update(*args, **kwargs)

                Navigation.objects.clear_cache()
        
        def delete(self, *args, **kwargs):
                Navigation.objects.clear_cache()
        
        def delete(self, *args, **kwargs):

-               super(NavigationQuerySet, self).delete(*args, **kwargs)
+               super(NavigationCacheQuerySet, self).delete(*args, **kwargs)

                Navigation.objects.clear_cache()
 
 
                Navigation.objects.clear_cache()
 
 

-class NavigationManager(TreeManager):
-       
-       # Analagous to contenttypes, cache Navigation to avoid repeated lookups all over the place.
-       # Navigation will probably be used frequently.
+class NavigationManager(models.Manager):
+       # Since navigation is going to be hit frequently and changed
+       # relatively infrequently, cache it. Analogous to contenttypes.
+       use_for_related = True

        _cache = {}
        
        def get_queryset(self):
        _cache = {}
        
        def get_queryset(self):

-               return NavigationQuerySet(self.model, using=self._db)
+               return NavigationCacheQuerySet(self.model, using=self._db)

        
        

-       def closest_navigation(self, node):
-               """
-               Returns the set of Navigation objects for a given node's navigation. This
-               will be the most recent set of defined hosted navigation among the node's
-               ancestors. Lookups are cached so that subsequent lookups for the same node
-               don't hit the database.
+       def get_cache_for(self, node, update_targets=True):
+               created = False
+               if not self.has_cache_for(node):
+                       self.create_cache_for(node)
+                       created = True

                
                

-               TODO: Should this create the auto-generated navigation in "physical" form?
-               """
-               try:
-                       return self._get_from_cache(self.db, node)
-               except KeyError:
-                       # Find the most recent host!
-                       ancestors = node.get_ancestors(ascending=True, include_self=True).annotate(num_navigation=models.Count("hosted_navigation"))
-                       
-                       # Iterate down the ancestors until you find one that:
-                       # a) is cached, or
-                       # b) has hosted navigation.
-                       nodes_to_cache = []
-                       host_node = None
-                       for ancestor in ancestors:
-                               if self._is_cached(self.db, ancestor) or ancestor.num_navigation > 0:
-                                       host_node = ancestor
-                                       break
-                               else:
-                                       nodes_to_cache.append(ancestor)
-                       
-                       if not self._is_cached(self.db, host_node):
-                               self._add_to_cache(self.db, host_node)
-                       
-                       # Cache the queryset instance for every node that was passed over, as well.
-                       hosted_navigation = self._get_from_cache(self.db, host_node)
-                       for node in nodes_to_cache:
-                               self._add_to_cache(self.db, node, hosted_navigation)
+               if update_targets and not created:
+                       self.update_targets_for(node)

                
                

-               return hosted_navigation
+               return self.__class__._cache[self.db][node]
+       
+       def has_cache_for(self, node):
+               return self.db in self.__class__._cache and node in self.__class__._cache[self.db]

        
        

-       def _add_to_cache(self, using, node, qs=None):
-               key = getattr(node, 'pk', None)
+       def create_cache_for(self, node):
+               "This method loops through the nodes ancestors and caches all unique navigation keys."
+               ancestors = node.get_ancestors(ascending=True, include_self=True)

                
                

-               if qs is None:
-                       if key is None:
-                               roots = self.none()
+               nodes_to_cache = []
+               
+               for node in ancestors:
+                       if self.has_cache_for(node):
+                               cache = self.get_cache_for(node).copy()
+                               break

                        else:
                        else:

-                               roots = node.hosted_navigation.select_related('target_node')
+                               nodes_to_cache.insert(0, node)
+               else:
+                       cache = {}
+               
+               for node in nodes_to_cache:
+                       cache = cache.copy()
+                       cache.update(self._build_cache_for(node))
+                       self.__class__._cache.setdefault(self.db, {})[node] = cache
+       
+       def _build_cache_for(self, node):
+               cache = {}
+               tree_id_attr = NavigationItem._mptt_meta.tree_id_attr
+               level_attr = NavigationItem._mptt_meta.level_attr
+               
+               for navigation in node.navigation_set.all():
+                       tree_ids = navigation.roots.values_list(tree_id_attr)
+                       items = list(NavigationItem.objects.filter(**{'%s__in' % tree_id_attr: tree_ids, '%s__lt' % level_attr: navigation.depth}).order_by('order', 'lft'))

                        
                        

-                       for root in roots:
-                               root_qs = root.get_descendants(include_self=True).complex_filter({'%s__lte' % root._mptt_meta.level_attr: root.get_level() + root.depth}).exclude(depth__isnull=True)
-                               if qs is None:
-                                       qs = root_qs
+                       root_items = []
+                       
+                       for item in items:
+                               item._is_cached = True
+                               
+                               if not hasattr(item, '_cached_children'):
+                                       item._cached_children = []
+                               
+                               if item.parent:
+                                       # alternatively, if I don't want to force it to a list, I could keep track of
+                                       # instances where the parent hasn't yet been met and do this step later for them.
+                                       # delayed action.
+                                       item.parent = items[items.index(item.parent)]
+                                       if not hasattr(item.parent, '_cached_children'):
+                                               item.parent._cached_children = []
+                                       item.parent._cached_children.append(item)

                                else:
                                else:

-                                       qs |= root_qs
-               
-                       if qs is None:
-                               qs = self.none()
+                                       root_items.append(item)
+                       
+                       cache[navigation.key] = {
+                               'navigation': navigation,
+                               'root_items': root_items,
+                               'items': items
+                       }

                
                

-               self.__class__._cache.setdefault(using, {})[key] = qs
+               return cache

        
        

-       def _get_from_cache(self, using, node):
-               key = getattr(node, 'pk', None)
-               return self.__class__._cache[self.db][key]
+       def clear_cache_for(self, node):
+               # Clear the cache for this node and all its descendants. The
+               # navigation for this node has probably changed, and for now,
+               # it isn't worth it to only clear the descendants actually
+               # affected by this.
+               if not self.has_cache_for(node):
+                       # Already cleared.
+                       return
+               
+               descendants = node.get_descendants(include_self=True)
+               cache = self.__class__._cache[self.db]
+               for node in descendants:
+                       cache.pop(node, None)

        
        

-       def _is_cached(self, using, node):
-               try:
-                       self._get_from_cache(using, node)
-               except KeyError:
-                       return False
-               return True
+       def update_targets_for(self, node):
+               # Manually update a cache's target nodes in case something's changed there.
+               # This should be a less complex operation than reloading the models each
+               # time. Not as good as selective updates... but not much to be done
+               # about that. TODO: Benchmark it.
+               caches = self.__class__._cache[self.db][node].values()
+               
+               items = []
+               
+               for cache in caches:
+                       items += cache['items']
+               
+               # A distinct query is not strictly necessary. TODO: benchmark the efficiency
+               # with/without distinct.
+               targets = list(Node.objects.filter(navigation_items__in=items).distinct())
+               
+               for cache in caches:
+                       for item in cache['items']:
+                               item.target_node = targets[targets.index(item.target_node)]

        
        

-       def clear_cache(self, navigation=None):
-               """
-               Clear out the navigation cache. This needs to happen during database flushes
-               or if a navigation entry is changed to prevent caching of outdated navigation information.
-               """
-               if navigation is None:
-                       self.__class__._cache.clear()
-               elif self.db in self.__class__._cache:
-                       cache = self.__class__._cache[self.db]
-                       for pk, qs in cache.items():
-                               if navigation in qs:
-                                       cache.pop(pk)
-
-
-class Navigation(TreeEntity):
+       def clear_cache(self):
+               self.__class__._cache.pop(self.db, None)
+
+
+class Navigation(Entity):

        objects = NavigationManager()
        objects = NavigationManager()

-       text = models.CharField(max_length=50)

        
        

-       hosting_node = models.ForeignKey(Node, blank=True, null=True, related_name='hosted_navigation', help_text="Be part of this node's root navigation.")
+       node = models.ForeignKey(Node, related_name='navigation_set', help_text="Be available as navigation for this node.")
+       key = models.CharField(max_length=255, validators=[RegexValidator("\w+")], help_text="Must contain one or more alphanumeric characters or underscores.")
+       depth = models.PositiveSmallIntegerField(default=DEFAULT_NAVIGATION_DEPTH, validators=[MinValueValidator(1)], help_text="Defines the maximum display depth of this navigation.")
+       
+       def __init__(self, *args, **kwargs):
+               super(Navigation, self).__init__(*args, **kwargs)
+               self._initial_data = model_to_dict(self)
+       
+       def __unicode__(self):
+               return "%s[%s]" % (self.node, self.key)
+       
+       def _has_changed(self):
+               return self._initial_data != model_to_dict(self)
+       
+       def save(self, *args, **kwargs):
+               super(Navigation, self).save(*args, **kwargs)
+               
+               if self._has_changed():
+                       Navigation.objects.clear_cache_for(self.node)
+                       self._initial_data = model_to_dict(self)
+       
+       def delete(self, *args, **kwargs):
+               super(Navigation, self).delete(*args, **kwargs)
+               Navigation.objects.clear_cache_for(self.node)
+       
+       class Meta:
+               unique_together = ('node', 'key')
+
+
+class NavigationItemManager(TreeManager):
+       use_for_related = True
+       
+       def get_queryset(self):
+               return NavigationCacheQuerySet(self.model, using=self._db)
+
+
+class NavigationItem(TreeEntity):
+       objects = NavigationItemManager()

        
        

-       target_node = models.ForeignKey(Node, blank=True, null=True, related_name='targeting_navigation', help_text="Point to this node's url.")
+       navigation = models.ForeignKey(Navigation, blank=True, null=True, related_name='roots', help_text="Be a root in this navigation tree.")
+       text = models.CharField(max_length=50)
+       
+       target_node = models.ForeignKey(Node, blank=True, null=True, related_name='navigation_items', help_text="Point to this node's url.")

        url_or_subpath = models.CharField(max_length=200, validators=[RedirectValidator()], blank=True, help_text="Point to this url or, if a node is defined and accepts subpaths, this subpath of the node.")
        reversing_parameters = JSONField(blank=True, help_text="If reversing parameters are defined, url_or_subpath will instead be interpreted as the view name to be reversed.")
        
        url_or_subpath = models.CharField(max_length=200, validators=[RedirectValidator()], blank=True, help_text="Point to this url or, if a node is defined and accepts subpaths, this subpath of the node.")
        reversing_parameters = JSONField(blank=True, help_text="If reversing parameters are defined, url_or_subpath will instead be interpreted as the view name to be reversed.")
        

-       order = models.PositiveSmallIntegerField(blank=True, null=True)
-       depth = models.PositiveSmallIntegerField(blank=True, null=True, default=DEFAULT_NAVIGATION_DEPTH, help_text="For the root of a hosted tree, defines the depth of the tree. A blank depth will hide this section of navigation. Otherwise, depth is ignored.")
+       order = models.PositiveSmallIntegerField(default=0)

        
        def __init__(self, *args, **kwargs):
        
        def __init__(self, *args, **kwargs):

-               super(Navigation, self).__init__(*args, **kwargs)
+               super(NavigationItem, self).__init__(*args, **kwargs)

                self._initial_data = model_to_dict(self)
                self._initial_data = model_to_dict(self)

+               self._is_cached = False

        
        def __unicode__(self):
                return self.get_path(field='text', pathsep=u' › ')
        
        def __unicode__(self):
                return self.get_path(field='text', pathsep=u' › ')


@@ -150,6 +236,9 @@ class Navigation(TreeEntity):
                        self.get_target_url()
                except NoReverseMatch, e:
                        raise ValidationError(e.message)
                        self.get_target_url()
                except NoReverseMatch, e:
                        raise ValidationError(e.message)

+               
+               if bool(self.parent) == bool(self.navigation):
+                       raise ValidationError("Exactly one of `parent` and `navigation` must be defined.")

        
        def get_target_url(self):
                node = self.target_node
        
        def get_target_url(self):
                node = self.target_node


@@ -172,29 +261,34 @@ class Navigation(TreeEntity):
        target_url = property(get_target_url)
        
        def is_active(self, request):
        target_url = property(get_target_url)
        
        def is_active(self, request):

-               # First check if this particular navigation is active. It is considered active if:
-               # - the requested node is this instance's target node and its subpath matches the requested path.
-               # - the requested node is a descendant of this instance's target node and this instance's target
-               #   node is not the hosting node of this navigation structure.
-               # - this instance has no target node and the url matches either the request path or the full url.
-               # - any of this instance's children are active.
-               node = request.node
-               
-               if self.target_node == node:
-                       if self.target_url == request.path:
-                               return True
-               elif self.target_node is None:
-                       if self.url_or_subpath == request.path or self.url_or_subpath == "http%s://%s%s" % (request.is_secure() and 's' or '', request.get_host(), request.path):
-                               return True
-               elif self.target_node.is_ancestor_of(node) and self.target_node != self.hosting_node:
+               if self.target_url == request.path:
+                       # Handle the `default` case where the target_url and requested path
+                       # are identical.
+                       return True
+               
+               if self.target_node is None and self.url_or_subpath == "http%s://%s%s" % (request.is_secure() and 's' or '', request.get_host(), request.path):
+                       # If there's no target_node, double-check whether it's a full-url
+                       # match.

                        return True
                
                        return True
                

-               # Always fall back to whether the node has active children.
-               return self.has_active_children(request)
+               if self.target_node and not self.url_or_subpath:
+                       # If there is a target node and it's targeted simply, but the target URL is not
+                       # 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
+               
+               return False

        
        

-       def has_active_children(self, request):
+       def has_active_descendants(self, request):

                for child in self.get_children():
                for child in self.get_children():

-                       if child.is_active(request):
+                       if child.is_active(request) or child.has_active_descendants(request):

                                return True
                return False
        
                                return True
                return False
        


@@ -203,16 +297,20 @@ class Navigation(TreeEntity):
                        return False
                return True
        
                        return False
                return True
        

+       def _clear_cache(self):
+               try:
+                       root = self.get_root()
+                       if self.get_level() < root.navigation.depth:
+                               Navigation.objects.clear_cache_for(self.get_root().navigation.node)
+               except AttributeError:
+                       pass
+       

        def save(self, *args, **kwargs):
        def save(self, *args, **kwargs):

-               super(Navigation, self).save(*args, **kwargs)
+               super(NavigationItem, self).save(*args, **kwargs)
+               

                if self._has_changed():
                if self._has_changed():

-                       self._initial_data = model_to_dict(self)
-                       Navigation.objects.clear_cache(self)
+                       self._clear_cache()

        
        def delete(self, *args, **kwargs):
        
        def delete(self, *args, **kwargs):

-               super(Navigation, self).delete(*args, **kwargs)
-               Navigation.objects.clear_cache(self)
-       
-       class Meta:
-               ordering = ['order']
-               verbose_name_plural = 'navigation'
\ No newline at end of file
+               super(NavigationItem, self).delete(*args, **kwargs)
+               self._clear_cache()
\ No newline at end of file