how can i invalidate page cache in django

Question

How can I invalidate page cache in django. I am trying to cache a page displays a list that is unique for each user using django-rest-framework. I can not figure out how to invalidate the page cache when the another object is added, updated, deleted from the model.

I am open to using an external package or signals.

I don't know what the key is for @page_cache to invalidate the cache

I have tried to use django-fancy-cache but I just get an error

unsupported operand type(s) for +: 'float' and 'function'

my cache settings

CACHES = {
    'default': {
         'BACKEND': 'django.core.cache.backends.locmem.LocMemCache',
         'LOCATION': 'unique-snowflake',
     }
}

the same user may view this page multiple times per minute. and the page is very processor heavy — user14665310, Jan 25 '22 at 19:06

score 1 · Answer 1 · answered Jan 25 '22 at 03:38

1

You can move your invalidation logic to your models. For example, in order to invalidate a cache when an object is added/updated, you can override model's save method. e.g:

def save(self, *args, **kwargs):
    cache.delete(`YOUR_CACHE_KEY`)
    super().save(*args, **kwargs)

same for delete:

def delete(self, *args, **kwargs):
    cache.delete(`YOUR_CACHE_KEY`)
    super().delete(*args, **kwargs)

answered Jan 25 '22 at 03:38

Moein Babapour

96
5

I know that I can delete the cache. the problem is that I don't know what the cache key is for the page – user14665310 Jan 25 '22 at 19:08
@user14665310 I think this link might be helpful https://stackoverflow.com/questions/2268417/expire-a-view-cache-in-django/36845722#36845722 – Moein Babapour Jan 26 '22 at 13:32
Thank you that answer did not help but a different answer did work https://stackoverflow.com/a/7455114/14665310 – user14665310 Jan 26 '22 at 19:56

how can i invalidate page cache in django

1 Answers1