Simplify last modified and etags processing for feeds

We had this elaborate system set up with caching and invalidation, which
is overkill since we cache the result of the view anyway. Just hit the
database when needed to find the last change to the respective model
class and be done with it.

Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 9 insertions, 5 deletions

diff --git a/feeds.py b/feeds.py
index feb8a84a..d1836178 100644
--- a/feeds.py
+++ b/feeds.py
@@ -4,11 +4,11 @@ from pytz import utc
 
 from django.contrib.sites.models import Site
 from django.contrib.syndication.views import Feed
+from django.db import connection
 from django.db.models import Q
 from django.utils.feedgenerator import Rss201rev2Feed
 from django.views.decorators.http import condition
 
-from main.utils import retrieve_latest
 from main.models import Arch, Repo, Package
 from news.models import News
 from releng.models import Release
@@ -64,13 +64,15 @@ class GuidNotPermalinkFeed(Rss201rev2Feed):
 
 
 def package_etag(request, *args, **kwargs):
-    latest = retrieve_latest(Package)
+    latest = package_last_modified(request)
     if latest:
         return hashlib.md5(str(kwargs) + str(latest)).hexdigest()
     return None
 
 def package_last_modified(request, *args, **kwargs):
-    return retrieve_latest(Package)
+    cursor = connection.cursor()
+    cursor.execute("SELECT MAX(last_update) FROM packages")
+    return cursor.fetchone()[0]
 
 
 class PackageFeed(Feed):
@@ -148,13 +150,15 @@ class PackageFeed(Feed):
 
 
 def news_etag(request, *args, **kwargs):
-    latest = retrieve_latest(News, 'last_modified')
+    latest = news_last_modified(request)
     if latest:
         return hashlib.md5(str(latest)).hexdigest()
     return None
 
 def news_last_modified(request, *args, **kwargs):
-    return retrieve_latest(News, 'last_modified')
+    cursor = connection.cursor()
+    cursor.execute("SELECT MAX(last_modified) FROM news")
+    return cursor.fetchone()[0]
 
 
 class NewsFeed(Feed):