from django.core.cache import cache
from django.conf import settings
from django.utils import importlib
from django.core.exceptions import ImproperlyConfigured
import hashlib
import time
import six
class BaseRosettaStorage(object):
def __init__(self, request):
self.request = request
def get(self, key, default=None):
raise NotImplementedError
def set(self, key, val):
raise NotImplementedError
def has(self, key):
raise NotImplementedError
def delete(self, key):
raise NotImplementedError
class DummyRosettaStorage(BaseRosettaStorage):
def get(self, key, default=None):
return default
def set(self, key, val):
pass
def has(self, key):
return False
def delete(self, key):
pass
class SessionRosettaStorage(BaseRosettaStorage):
def get(self, key, default=None):
if key in self.request.session:
return self.request.session[key]
return default
def set(self, key, val):
self.request.session[key] = val
def has(self, key):
return key in self.request.session
def delete(self, key):
del(self.request.session[key])
class CacheRosettaStorage(BaseRosettaStorage):
# unlike the session storage backend, cache is shared among all users
# so we need to per-user key prefix, which we store in the session
def __init__(self, request):
super(CacheRosettaStorage, self).__init__(request)
if 'rosetta_cache_storage_key_prefix' in self.request.session:
self._key_prefix = self.request.session['rosetta_cache_storage_key_prefix']
else:
self._key_prefix = hashlib.new('sha1', six.text_type(time.time()).encode('utf8')).hexdigest()
self.request.session['rosetta_cache_storage_key_prefix'] = self._key_prefix
70 if self.request.session['rosetta_cache_storage_key_prefix'] != self._key_prefix:
raise ImproperlyConfigured("You can't use the CacheRosettaStorage because your Django Session storage doesn't seem to be working. The CacheRosettaStorage relies on the Django Session storage to avoid conflicts.")
# Make sure we're not using DummyCache
74 if 'dummycache' in settings.CACHES['default']['BACKEND'].lower():
raise ImproperlyConfigured("You can't use the CacheRosettaStorage if your cache isn't correctly set up (you are use the DummyCache cache backend).")
# Make sure the actually actually works
try:
self.set('rosetta_cache_test', 'rosetta')
80 if not self.get('rosetta_cache_test') == 'rosetta':
raise ImproperlyConfigured("You can't use the CacheRosettaStorage if your cache isn't correctly set up, please double check your Django DATABASES setting and that the cache server is responding.")
finally:
self.delete('rosetta_cache_test')
def get(self, key, default=None):
#print ('get', self._key_prefix + key)
return cache.get(self._key_prefix + key, default)
def set(self, key, val):
#print ('set', self._key_prefix + key)
cache.set(self._key_prefix + key, val, 86400)
def has(self, key):
#print ('has', self._key_prefix + key)
return (self._key_prefix + key) in cache
def delete(self, key):
#print ('del', self._key_prefix + key)
cache.delete(self._key_prefix + key)
def get_storage(request):
from rosetta.conf import settings
storage_module, storage_class = settings.STORAGE_CLASS.rsplit('.', 1)
storage_module = importlib.import_module(storage_module)
return getattr(storage_module, storage_class)(request)
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