cachemodel.py

""" Cache <-> Object Mapper

I know there is `rom <https://pypi.python.org/pypi/rom>`_ or some.
"""
import json

from django.core.cache import cache


SEPARATOR = ':'


class CacheModel(object):
    key_attribute = ''
    attribute_names = ()

    def __init__(self, **kwargs):
        for attr in self.attribute_names:
            init_value = kwargs.get(attr, None)
            setattr(self, attr, init_value)

    @classmethod
    def generate_key(cls, key_value):
        class_name = cls.__name__
        module_name = __name__
        return module_name + '.' + class_name + SEPARATOR + key_value

    @property
    def key(self):
        return self.generate_key(getattr(self, self.key_attribute))

    @staticmethod
    def serialize(obj):
        return json.dumps(obj)

    @staticmethod
    def deserialize(dumped):
        return json.loads(dumped)

    @property
    def attributes(self):
        return {attr: getattr(self, attr, None) for attr in self.attribute_names}

    @classmethod
    def get(cls, key):
        dumped = cache.get(cls.generate_key(key))
        return cls.deserialize(dumped)

    def save(self):
        dumped = self.serialize(self.attributes)
        return cache.set(self.key, dumped)