diff options
| -rw-r--r-- | feeds.py | 14 | ||||
| -rw-r--r-- | main/models.py | 6 | ||||
| -rw-r--r-- | main/utils.py | 42 | ||||
| -rw-r--r-- | news/models.py | 7 |
4 files changed, 12 insertions, 57 deletions
@@ -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): diff --git a/main/models.py b/main/models.py index 09b1adc0..1b95f3fa 100644 --- a/main/models.py +++ b/main/models.py @@ -443,12 +443,8 @@ class PackageFile(models.Model): db_table = 'package_files' -# connect signals needed to keep cache in line with reality -from main.utils import refresh_latest -from django.db.models.signals import pre_save, post_save +from django.db.models.signals import pre_save -post_save.connect(refresh_latest, sender=Package, - dispatch_uid="main.models") # note: reporead sets the 'created' field on Package objects, so no signal # listener is set up here to do so pre_save.connect(set_created_field, sender=Donor, diff --git a/main/utils.py b/main/utils.py index 97cc540a..cf156566 100644 --- a/main/utils.py +++ b/main/utils.py @@ -12,11 +12,6 @@ from django.utils.timezone import now from django.template.defaultfilters import slugify -CACHE_TIMEOUT = 1800 -INVALIDATE_TIMEOUT = 10 -CACHE_LATEST_PREFIX = 'cache_latest_' - - def cache_function_key(func, args, kwargs): raw = [func.__name__, func.__module__, args, kwargs] pickled = pickle.dumps(raw, protocol=pickle.HIGHEST_PROTOCOL) @@ -76,43 +71,6 @@ def format_http_headers(request): make_choice = lambda l: [(str(m), str(m)) for m in l] -# These are in here because we would be jumping around in some import circles -# and hoops otherwise. The only thing currently using these keys is the feed -# caching stuff. - -def refresh_latest(**kwargs): - '''A post_save signal handler to clear out the cached latest value for a - given model.''' - cache_key = CACHE_LATEST_PREFIX + kwargs['sender'].__name__ - # We could delete the value, but that could open a race condition - # where the new data wouldn't have been committed yet by the calling - # thread. Instead, explicitly set it to None for a short amount of time. - # Hopefully by the time it expires we will have committed, and the cache - # will be valid again. See "Scaling Django" by Mike Malone, slide 30. - cache.set(cache_key, None, INVALIDATE_TIMEOUT) - - -def retrieve_latest(sender, latest_by=None): - # we could break this down based on the request url, but it would probably - # cost us more in query time to do so. - cache_key = CACHE_LATEST_PREFIX + sender.__name__ - latest = cache.get(cache_key) - if latest: - return latest - try: - if latest_by is None: - latest_by = sender._meta.get_latest_by - latest = sender.objects.values(latest_by).latest(latest_by)[latest_by] - # Using add means "don't overwrite anything in there". What could be in - # there is an explicit None value that our refresh signal set, which - # means we want to avoid race condition possibilities for a bit. - cache.add(cache_key, latest, CACHE_TIMEOUT) - return latest - except sender.DoesNotExist: - pass - return None - - def set_created_field(sender, **kwargs): '''This will set the 'created' field on any object to the current UTC time if it is unset. diff --git a/news/models.py b/news/models.py index d51db7c7..985c1088 100644 --- a/news/models.py +++ b/news/models.py @@ -45,12 +45,9 @@ def set_news_fields(sender, **kwargs): news.guid = 'tag:%s,%s:%s' % (Site.objects.get_current(), current_time.strftime('%Y-%m-%d'), news.get_absolute_url()) -# connect signals needed to keep cache in line with reality -from main.utils import refresh_latest -from django.db.models.signals import pre_save, post_save -post_save.connect(refresh_latest, sender=News, - dispatch_uid="news.models") +from django.db.models.signals import pre_save + pre_save.connect(set_news_fields, sender=News, dispatch_uid="news.models") |