def learn_cache_key(request, response, cache_timeout=None, key_prefix=None, cache=None):
"""
Learns what headers to take into account for some request path from the
response object. It stores those headers in a global path registry so that
later access to that path will know what headers to take into account
without building the response object itself. The headers are named in the
Vary header of the response, but we want to prevent response generation.
The list of headers to use for cache key generation is stored in the same
cache as the pages themselves. If the cache ages some data out of the
cache, this just means that we have to build the response once to get at
the Vary header and so at the list of headers to use for the cache key.
"""
if key_prefix is None:
key_prefix = settings.CACHE_MIDDLEWARE_KEY_PREFIX
if cache_timeout is None:
cache_timeout = settings.CACHE_MIDDLEWARE_SECONDS
cache_key = _generate_cache_header_key(key_prefix, request)
if cache is None:
cache = get_cache(settings.CACHE_MIDDLEWARE_ALIAS)
if response.has_header('Vary'):
headerlist = ['HTTP_'+header.upper().replace('-', '_')
for header in cc_delim_re.split(response['Vary'])]
cache.set(cache_key, headerlist, cache_timeout)
return _generate_cache_key(request, request.method, headerlist, key_prefix)
else:
# if there is no Vary header, we still need a cache key
# for the request.get_full_path()
cache.set(cache_key, [], cache_timeout)
return _generate_cache_key(request, request.method, [], key_prefix)
def __init__(self):
self.cache_timeout = settings.CACHE_MIDDLEWARE_SECONDS
self.key_prefix = settings.CACHE_MIDDLEWARE_KEY_PREFIX
self.cache_anonymous_only = getattr(settings,
'CACHE_MIDDLEWARE_ANONYMOUS_ONLY',
False)
self.cache_alias = settings.CACHE_MIDDLEWARE_ALIAS
self.cache = get_cache(self.cache_alias)
def create_test_db(self, verbosity=1, autoclobber=False):
"""
Creates a test database, prompting the user for confirmation if the
database already exists. Returns the name of the test database created.
"""
# Don't import my_django.core.management if it isn't needed.
from my_django.core.management import call_command
test_database_name = self._get_test_db_name()
if verbosity >= 1:
test_db_repr = ''
if verbosity >= 2:
test_db_repr = " ('%s')" % test_database_name
print "Creating test database for alias '%s'%s..." % (
self.connection.alias, test_db_repr)
self._create_test_db(verbosity, autoclobber)
self.connection.close()
self.connection.settings_dict["NAME"] = test_database_name
# Confirm the feature set of the test database
self.connection.features.confirm()
# Report syncdb messages at one level lower than that requested.
# This ensures we don't get flooded with messages during testing
# (unless you really ask to be flooded)
call_command('syncdb',
verbosity=max(verbosity - 1, 0),
interactive=False,
database=self.connection.alias,
load_initial_data=False)
# We need to then do a flush to ensure that any data installed by
# custom SQL has been removed. The only test data should come from
# test fixtures, or autogenerated from post_syncdb triggers.
# This has the side effect of loading initial data (which was
# intentionally skipped in the syncdb).
call_command('flush',
verbosity=max(verbosity - 1, 0),
interactive=False,
database=self.connection.alias)
from my_django.core.cache import get_cache
from my_django.core.cache.backends.db import BaseDatabaseCache
for cache_alias in settings.CACHES:
cache = get_cache(cache_alias)
if isinstance(cache, BaseDatabaseCache):
call_command('createcachetable',
cache._table,
database=self.connection.alias)
# Get a cursor (even though we don't need one yet). This has
# the side effect of initializing the test database.
self.connection.cursor()
return test_database_name
def __init__(self, *args, **kwargs):
super(CachedFilesMixin, self).__init__(*args, **kwargs)
try:
self.cache = get_cache('staticfiles')
except InvalidCacheBackendError:
# Use the default backend
self.cache = default_cache
self._patterns = SortedDict()
for extension, patterns in self.patterns:
for pattern in patterns:
compiled = re.compile(pattern)
self._patterns.setdefault(extension, []).append(compiled)
def __init__(self,
cache_timeout=None,
cache_anonymous_only=None,
**kwargs):
# We need to differentiate between "provided, but using default value",
# and "not provided". If the value is provided using a default, then
# we fall back to system defaults. If it is not provided at all,
# we need to use middleware defaults.
cache_kwargs = {}
try:
self.key_prefix = kwargs['key_prefix']
if self.key_prefix is not None:
cache_kwargs['KEY_PREFIX'] = self.key_prefix
else:
self.key_prefix = ''
except KeyError:
self.key_prefix = settings.CACHE_MIDDLEWARE_KEY_PREFIX
cache_kwargs['KEY_PREFIX'] = self.key_prefix
try:
self.cache_alias = kwargs['cache_alias']
if self.cache_alias is None:
self.cache_alias = DEFAULT_CACHE_ALIAS
if cache_timeout is not None:
cache_kwargs['TIMEOUT'] = cache_timeout
except KeyError:
self.cache_alias = settings.CACHE_MIDDLEWARE_ALIAS
if cache_timeout is None:
cache_kwargs['TIMEOUT'] = settings.CACHE_MIDDLEWARE_SECONDS
else:
cache_kwargs['TIMEOUT'] = cache_timeout
if cache_anonymous_only is None:
self.cache_anonymous_only = getattr(
settings, 'CACHE_MIDDLEWARE_ANONYMOUS_ONLY', False)
else:
self.cache_anonymous_only = cache_anonymous_only
self.cache = get_cache(self.cache_alias, **cache_kwargs)
self.cache_timeout = self.cache.default_timeout
def get_cache_key(request, key_prefix=None, method='GET', cache=None):
"""
Returns a cache key based on the request path and query. It can be used
in the request phase because it pulls the list of headers to take into
account from the global path registry and uses those to build a cache key
to check against.
If there is no headerlist stored, the page needs to be rebuilt, so this
function returns None.
"""
if key_prefix is None:
key_prefix = settings.CACHE_MIDDLEWARE_KEY_PREFIX
cache_key = _generate_cache_header_key(key_prefix, request)
if cache is None:
cache = get_cache(settings.CACHE_MIDDLEWARE_ALIAS)
headerlist = cache.get(cache_key, None)
if headerlist is not None:
return _generate_cache_key(request, method, headerlist, key_prefix)
else:
return None