Added memoization to TargetURLModel.get_target_url.

[philo.git] / philo / models / nodes.py

diff --git a/philo/models/nodes.py b/philo/models/nodes.py
index 830f94a..58d1b96 100644 (file)
--- a/philo/models/nodes.py
+++ b/philo/models/nodes.py
@@ -2,9 +2,11 @@ from inspect import getargspec
 import mimetypes
 from os.path import basename
 
+from django.conf import settings
 from django.contrib.contenttypes import generic
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.sites.models import Site, RequestSite
+from django.core.cache import cache
 from django.core.exceptions import ValidationError
 from django.core.servers.basehttp import FileWrapper
 from django.core.urlresolvers import resolve, clear_url_caches, reverse, NoReverseMatch
@@ -24,6 +26,7 @@ __all__ = ('Node', 'View', 'MultiView', 'Redirect', 'File')
 
 
 _view_content_type_limiter = ContentTypeSubclassLimiter(None)
+CACHE_PHILO_ROOT = getattr(settings, "PHILO_CACHE_PHILO_ROOT", True)
 
 
 class Node(SlugTreeEntity):
@@ -71,6 +74,8 @@ class Node(SlugTreeEntity):
                
                Node urls will not contain a trailing slash unless a subpath is provided which ends with a trailing slash. Subpaths are expected to begin with a slash, as if returned by :func:`django.core.urlresolvers.reverse`.
                
+               Because this method will be called frequently and will always try to reverse ``philo-root``, the results of that reversal will be cached by default. This can be disabled by setting :setting:`PHILO_CACHE_PHILO_ROOT` to ``False``.
+               
                :meth:`construct_url` may raise the following exceptions:
                
                - :class:`NoReverseMatch` if "philo-root" is not reversable -- for example, if :mod:`philo.urls` is not included anywhere in your urlpatterns.
@@ -85,7 +90,14 @@ class Node(SlugTreeEntity):
                
                """
                # Try reversing philo-root first, since we can't do anything if that fails.
-               root_url = reverse('philo-root')
+               if CACHE_PHILO_ROOT:
+                       key = "CACHE_PHILO_ROOT__" + settings.ROOT_URLCONF
+                       root_url = cache.get(key)
+                       if root_url is None:
+                               root_url = reverse('philo-root')
+                               cache.set(key, root_url)
+               else:
+                       root_url = reverse('philo-root')
                
                try:
                        current_site = Site.objects.get_current()
@@ -323,8 +335,17 @@ class TargetURLModel(models.Model):
                        kwargs = dict([(smart_str(k, 'ascii'), v) for k, v in params.items()])
                return self.url_or_subpath, args, kwargs
        
-       def get_target_url(self):
-               """Calculates and returns the target url based on the :attr:`target_node`, :attr:`url_or_subpath`, and :attr:`reversing_parameters`."""
+       def get_target_url(self, memoize=True):
+               """Calculates and returns the target url based on the :attr:`target_node`, :attr:`url_or_subpath`, and :attr:`reversing_parameters`. The results will be memoized by default; this can be prevented by passing in ``memoize=False``."""
+               if memoize:
+                       memo_args = (self.target_node_id, self.url_or_subpath, self.reversing_parameters_json)
+                       try:
+                               return self._target_url_memo[memo_args]
+                       except AttributeError:
+                               self._target_url_memo = {}
+                       except KeyError:
+                               pass
+               
                node = self.target_node
                if node is not None and node.accepts_subpath and self.url_or_subpath:
                        if self.reversing_parameters is not None:
@@ -334,14 +355,19 @@ class TargetURLModel(models.Model):
                                subpath = self.url_or_subpath
                                if subpath[0] != '/':
                                        subpath = '/' + subpath
-                       return node.construct_url(subpath)
+                       target_url = node.construct_url(subpath)
                elif node is not None:
-                       return node.get_absolute_url()
+                       target_url = node.get_absolute_url()
                else:
                        if self.reversing_parameters is not None:
                                view_name, args, kwargs = self.get_reverse_params()
-                               return reverse(view_name, args=args, kwargs=kwargs)
-                       return self.url_or_subpath
+                               target_url = reverse(view_name, args=args, kwargs=kwargs)
+                       else:
+                               target_url = self.url_or_subpath
+               
+               if memoize:
+                       self._target_url_memo[memo_args] = target_url
+               return target_url
        target_url = property(get_target_url)
        
        class Meta: