"""Utils."""
from django.conf import settings
from django.core.cache import cache
from django.http import HttpRequest
from django.utils.cache import get_cache_key
[docs]def invalidate_cache(path=""):
"""This function uses Django's caching function get_cache_key().
Since 1.7, Django has used more variables from the request object (scheme, host,
path, and query string) in order to create the MD5 hashed part of the
cache_key. Additionally, Django will use your server's timezone and
language as properties as well. If internationalization is important to
your application, you will most likely need to adapt this function to
handle that appropriately.
Bootstrap request:
request.path should point to the view endpoint you want to invalidate
request.META must include the correct
SERVER_NAME and SERVER_PORT as django uses these in order
to build a MD5 hashed value for the cache_key. Similarly, we need to artificially set the
language code on the request to 'en-us' to match the initial creation of the cache_key.
YMMV regarding the language code.
"""
request = HttpRequest()
request.META = settings.CACHE_META_INVALIDATION
request.LANGUAGE_CODE = "en-us"
request.path = path
try:
cache_key = get_cache_key(request)
if cache_key:
if cache_key in cache:
cache.delete(cache_key)
return (True, "successfully invalidated")
return (False, "cache_key does not exist in cache")
raise ValueError("failed to create cache_key")
except (ValueError, Exception) as err:
return (False, err)
# pylint: disable=unused-argument
[docs]def is_panic_activated(request):
"""This function return True if panic mode is activated."""
return {"PANIC": cache.get(settings.PANIC_KEY)}
[docs]class Singleton(type):
"""Singleton Metaclass."""
_instances = {}
def __call__(cls, *args, **kwargs):
"""Singleton Call."""
if cls not in cls._instances:
cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
return cls._instances[cls]
[docs]def depth(_dict: dict) -> int:
"""Compute the depth of a dict."""
if isinstance(_dict, dict):
return 1 + (max(map(depth, _dict.values())) if _dict else 0)
return 0