Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Browse files

Fixed #3766 -- Added in-memory caching for the sites framework. Will …

…speed up all the "current site" lookups. Thanks, Matt Riggott.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@6180 bcc190cf-cafb-0310-a4f2-bffc1f526a37
  • Loading branch information...
commit 36396fb4307af9764b2f8c53f8f0fcb926be249e 1 parent bc21612
@malcolmt malcolmt authored
Showing with 43 additions and 1 deletion.
  1. +18 −1 django/contrib/sites/models.py
  2. +25 −0 docs/sites.txt
View
19 django/contrib/sites/models.py
@@ -2,15 +2,32 @@
from django.utils.translation import ugettext_lazy as _
from django.http import get_host
+SITE_CACHE = {}
+
class SiteManager(models.Manager):
def get_current(self):
+ """
+ Returns the current ``Site`` based on the SITE_ID in the
+ project's settings. The ``Site`` object is cached the first
+ time it's retrieved from the database.
+ """
from django.conf import settings
try:
sid = settings.SITE_ID
except AttributeError:
from django.core.exceptions import ImproperlyConfigured
raise ImproperlyConfigured("You're using the Django \"sites framework\" without having set the SITE_ID setting. Create a site in your database and set the SITE_ID setting to fix this error.")
- return self.get(pk=sid)
+ try:
+ current_site = SITE_CACHE[sid]
+ except KeyError:
+ current_site = self.get(pk=sid)
+ SITE_CACHE[sid] = current_site
+ return current_site
+
+ def clear_cache(self):
+ """Clears the ``Site`` object cache."""
+ global SITE_CACHE
+ SITE_CACHE = {}
class Site(models.Model):
domain = models.CharField(_('domain name'), max_length=100)
View
25 docs/sites.txt
@@ -213,6 +213,31 @@ To do this, you can use the sites framework. A simple example::
>>> 'http://%s%s' % (Site.objects.get_current().domain, obj.get_absolute_url())
'http://example.com/mymodel/objects/3/'
+Caching the current ``Site`` object
+===================================
+
+**New in Django development version**
+
+As the current site is stored in the database, each call to
+``Site.objects.get_current()`` could result in a database query. But Django is a
+little cleverer than that: on the first request, the current site is cached, and
+any subsequent call returns the cached data instead of hitting the database.
+
+If for any reason you want to force a database query, you can tell Django to
+clear the cache using ``Site.objects.clear_cache()``::
+
+ # First call; current site fetched from database.
+ current_site = Site.objects.get_current()
+ # ...
+
+ # Second call; current site fetched from cache.
+ current_site = Site.objects.get_current()
+ # ...
+
+ # Force a database query for the third call.
+ Site.objects.clear_cache()
+ current_site = Site.objects.get_current()
+
The ``CurrentSiteManager``
==========================
Please sign in to comment.
Something went wrong with that request. Please try again.