Fixed #16042 -- Use the content types caching in the comments contrib app. Thanks, ptone, Julien Phalip and Thejaswi Puthraya.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16737 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/comments/templatetags/comments.py

@@ -47,7 +47,7 @@ class BaseCommentNode(template.Node):
     def lookup_content_type(token, tagname):
         try:
             app, model = token.split('.')
-            return ContentType.objects.get(app_label=app, model=model)
+            return ContentType.objects.get_by_natural_key(app, model)
         except ValueError:
             raise template.TemplateSyntaxError("Third argument in %r must be in the format 'app.model'" % tagname)
         except ContentType.DoesNotExist:

tests/regressiontests/comment_tests/tests/templatetag_tests.py

@@ -1,4 +1,7 @@
+from __future__ import with_statement
+
 from django.contrib.comments.forms import CommentForm
+from django.contrib.comments.models import Comment
 from django.contrib.contenttypes.models import ContentType
 from django.template import Template, Context
 from regressiontests.comment_tests.models import Article, Author
@@ -44,30 +47,41 @@ class CommentTemplateTagTests(CommentTestCase):
             self.testRenderCommentFormFromObject()
         self.assertNumQueries(1, test)
 
-    def testGetCommentCount(self, tag=None):
+    def verifyGetCommentCount(self, tag=None):
-        self.createSomeComments()
         t = "{% load comments %}" + (tag or "{% get_comment_count for comment_tests.article a.id as cc %}") + "{{ cc }}"
         ctx, out = self.render(t, a=Article.objects.get(pk=1))
         self.assertEqual(out, "2")
 
+    def testGetCommentCount(self):
+        self.createSomeComments()
+        self.verifyGetCommentCount("{% get_comment_count for comment_tests.article a.id as cc %}")
+
     def testGetCommentCountFromLiteral(self):
-        self.testGetCommentCount("{% get_comment_count for comment_tests.article 1 as cc %}")
+        self.createSomeComments()
+        self.verifyGetCommentCount("{% get_comment_count for comment_tests.article 1 as cc %}")
 
     def testGetCommentCountFromObject(self):
-        self.testGetCommentCount("{% get_comment_count for a as cc %}")
+        self.createSomeComments()
+        self.verifyGetCommentCount("{% get_comment_count for a as cc %}")
 
-    def testGetCommentList(self, tag=None):
+    def verifyGetCommentList(self, tag=None):
-        c1, c2, c3, c4 = self.createSomeComments()
+        c1, c2, c3, c4 = Comment.objects.all()[:4]
-        t = "{% load comments %}" + (tag or "{% get_comment_list for comment_tests.author a.id as cl %}")
+        t = "{% load comments %}" +  (tag or "{% get_comment_list for comment_tests.author a.id as cl %}")
         ctx, out = self.render(t, a=Author.objects.get(pk=1))
         self.assertEqual(out, "")
         self.assertEqual(list(ctx["cl"]), [c2])
 
+    def testGetCommentList(self):
+        self.createSomeComments()
+        self.verifyGetCommentList("{% get_comment_list for comment_tests.author a.id as cl %}")
+
     def testGetCommentListFromLiteral(self):
-        self.testGetCommentList("{% get_comment_list for comment_tests.author 1 as cl %}")
+        self.createSomeComments()
+        self.verifyGetCommentList("{% get_comment_list for comment_tests.author 1 as cl %}")
 
     def testGetCommentListFromObject(self):
-        self.testGetCommentList("{% get_comment_list for a as cl %}")
+        self.createSomeComments()
+        self.verifyGetCommentList("{% get_comment_list for a as cl %}")
 
     def testGetCommentPermalink(self):
         c1, c2, c3, c4 = self.createSomeComments()
@@ -99,3 +113,63 @@ class CommentTemplateTagTests(CommentTestCase):
     def testRenderCommentListFromObject(self):
         self.testRenderCommentList("{% render_comment_list for a %}")
 
+    def testNumberQueries(self):
+        """
+        Ensure that the template tags use cached content types to reduce the
+        number of DB queries.
+        Refs #16042.
+        """
+
+        self.createSomeComments()
+
+        # {% render_comment_list %} -----------------
+
+        # Clear CT cache
+        ContentType.objects.clear_cache()
+        with self.assertNumQueries(4):
+            self.testRenderCommentListFromObject()
+
+        # Force the CT to be cached
+        ct = ContentType.objects.get_for_model(Article)
+        with self.assertNumQueries(3):
+            self.testRenderCommentListFromObject()
+
+        # {% get_comment_list %} --------------------
+
+        ContentType.objects.clear_cache()
+        with self.assertNumQueries(4):
+            self.verifyGetCommentList()
+
+        ct = ContentType.objects.get_for_model(Author)
+        with self.assertNumQueries(3):
+            self.verifyGetCommentList()
+
+        # {% render_comment_form %} -----------------
+
+        ContentType.objects.clear_cache()
+        with self.assertNumQueries(3):
+            self.testRenderCommentForm()
+
+        ct = ContentType.objects.get_for_model(Article)
+        with self.assertNumQueries(2):
+            self.testRenderCommentForm()
+
+        # {% get_comment_form %} --------------------
+
+        ContentType.objects.clear_cache()
+        with self.assertNumQueries(3):
+            self.testGetCommentForm()
+
+        ct = ContentType.objects.get_for_model(Article)
+        with self.assertNumQueries(2):
+            self.testGetCommentForm()
+
+        # {% get_comment_count %} -------------------
+
+        ContentType.objects.clear_cache()
+        with self.assertNumQueries(3):
+            self.verifyGetCommentCount()
+
+        ct = ContentType.objects.get_for_model(Article)
+        with self.assertNumQueries(2):
+            self.verifyGetCommentCount()