This mixin is intended for small lookup-style models that contain mostly static data and referenced by foreign keys from many other places. A good example is a list of Payment options in an e-shop that is referenced from Orders and is hitting database order.payment
at least one time for an order.
The idea is to cache entire table in a dict in memory that will live for entire life of a whole process serving many requests.
The downside is that you need to restart the server when a cached lookup table changes.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | # Mixin:
class CachedGet(object):
def get(self, *args, **kwargs):
pk_name = self.model._meta.pk.name
if not hasattr(self, '_cache'):
self._cache = dict((obj._get_pk_val(), obj) for obj in self.all())
value = len(kwargs) == 1 and kwargs.keys()[0] in ('pk', pk_name, '%s__exact' % pk_name) and self._cache.get(kwargs.values()[0], False)
if value:
return value
else:
super(CachedGet, self).get(*args, **kwargs)
# Usage:
class MyModel(CachedGet, models.Model):
# ...
|
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