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-rw-r--r--main/utils.py25
1 files changed, 20 insertions, 5 deletions
diff --git a/main/utils.py b/main/utils.py
index 81f689e7..e7e47c53 100644
--- a/main/utils.py
+++ b/main/utils.py
@@ -4,20 +4,24 @@ except ImportError:
import pickle
from datetime import datetime
+import hashlib
+from pytz import utc
from django.core.cache import cache
-from django.utils.hashcompat import md5_constructor
+
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)
- key = md5_constructor(pickled).hexdigest()
+ key = hashlib.md5(pickled).hexdigest()
return 'cache_function.' + func.__name__ + '.' + key
+
def cache_function(length):
"""
A variant of the snippet posted by Jeff Wheeler at
@@ -43,6 +47,7 @@ def cache_function(length):
return inner_func
return decorator
+
def clear_cache_function(func, args, kwargs):
key = cache_function_key(func, args, kwargs)
cache.delete(key)
@@ -50,6 +55,7 @@ def clear_cache_function(func, args, kwargs):
# utility to make a pair of django choices
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.
@@ -65,6 +71,7 @@ def refresh_latest(**kwargs):
# will be valid again. See "Scaling Django" by Mike Malone, slide 30.
cache.set(cache_key, None, INVALIDATE_TIMEOUT)
+
def retrieve_latest(sender):
# we could break this down based on the request url, but it would probably
# cost us more in query time to do so.
@@ -84,12 +91,19 @@ def retrieve_latest(sender):
pass
return None
+
+def utc_now():
+ '''Returns a timezone-aware UTC date representing now.'''
+ return datetime.utcnow().replace(tzinfo=utc)
+
+
def set_created_field(sender, **kwargs):
- '''This will set the 'created' field on any object to datetime.utcnow() if
- it is unset. For use as a pre_save signal handler.'''
+ '''This will set the 'created' field on any object to the current UTC time
+ if it is unset. For use as a pre_save signal handler.'''
obj = kwargs['instance']
if hasattr(obj, 'created') and not obj.created:
- obj.created = datetime.utcnow()
+ obj.created = utc_now()
+
def groupby_preserve_order(iterable, keyfunc):
'''Take an iterable and regroup using keyfunc to determine whether items
@@ -112,6 +126,7 @@ def groupby_preserve_order(iterable, keyfunc):
return result
+
class PackageStandin(object):
'''Resembles a Package object, and has a few of the same fields, but is
really a link to a pkgbase that has no package with matching pkgname.'''