Merge branch 'cache-auth-user'

airmozilla/auth/backend.py

@@ -0,0 +1,25 @@
+from django_browserid.auth import BrowserIDBackend
+from django.core.cache import cache
+
+
+class AirmozillaBrowserIDBackend(BrowserIDBackend):
+    """The only difference between this backend and the default
+    BrowserIDBackend backend is that this one uses the cache framework
+    to remember the user.
+
+    The cache is invalidated by a post_save signal in this app's models.py.
+    """
+
+    def get_user(self, user_id):
+        if not user_id:
+            return None
+        cache_key = 'user:%s' % (user_id,)
+        user = cache.get(cache_key)
+        if user:
+            return user
+        try:
+            user = self.User.objects.get(pk=user_id)
+            cache.set(cache_key, user, 60 * 60)
+            return user
+        except self.User.DoesNotExist:
+            return None

airmozilla/auth/models.py

@@ -1 +1,11 @@
-# delete me
+from django.core.cache import cache
+from django.dispatch import receiver
+from django.contrib.auth.models import User
+from django.db import models
+
+
+@receiver(models.signals.post_save, sender=User)
+def invalidate_user_cache(sender, instance, **kwargs):
+    if instance.id:
+        cache_key = 'user:%s' % (instance.id,)
+        cache.delete(cache_key)

airmozilla/auth/tests/test_backend.py

@@ -0,0 +1,43 @@
+from django.test import TestCase
+from django.contrib.auth.models import User
+
+from nose.tools import eq_
+
+from airmozilla.auth.backend import AirmozillaBrowserIDBackend
+
+
+class TestBackend(TestCase):
+
+    # def setUp(self):
+    #     super(TestViews, self).setUp()
+
+    def shortDescription(self):
+        # Stop nose using the test docstring and instead the test method name.
+        pass
+
+    def test_getuser_none(self):
+        backend = AirmozillaBrowserIDBackend()
+        eq_(backend.get_user(0), None)
+        eq_(backend.get_user(None), None)
+
+    def test_getuser_known(self):
+        backend = AirmozillaBrowserIDBackend()
+        user = User.objects.create(username='richard')
+        eq_(backend.get_user(user.id), user)
+        # a second time and it should be coming from the cache
+        eq_(backend.get_user(user.id), user)
+        # change the user and it should be reflected
+        user.username = 'zandr'
+        user.save()
+        eq_(backend.get_user(user.id).username, 'zandr')
+        # a second time
+        eq_(backend.get_user(user.id).username, 'zandr')
+
+    def test_getuser_deleted(self):
+        backend = AirmozillaBrowserIDBackend()
+        user = User.objects.create(username='richard')
+        eq_(backend.get_user(user.id), user)
+        # twice
+        eq_(backend.get_user(user.id), user)
+        user.delete()
+        eq_(backend.get_user(user.id), None)

airmozilla/settings/base.py

@@ -51,6 +51,10 @@
 # BrowserID configuration
 AUTHENTICATION_BACKENDS = [
     'django.contrib.auth.backends.ModelBackend',
+    # this is the first one that matters
+    '%s.auth.backend.AirmozillaBrowserIDBackend' % PROJECT_MODULE,
+    # but we're keeping this in case people still have sessions
+    # whose backend cookie points to this class path
     'django_browserid.auth.BrowserIDBackend',
 ]