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-rw-r--r--main/models.py6
-rw-r--r--main/utils.py42
2 files changed, 1 insertions, 47 deletions
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.