58 lines
1.9 KiB
Python
58 lines
1.9 KiB
Python
"""Modulo que contiene la clase/decorador Cache, contiene su logger y una conexión a redis"""
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import json
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import logging
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from blake3 import blake3 # pylint: disable=no-name-in-module
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from redis import Redis
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from django.conf import settings
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_log = logging.getLogger(__name__)
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_log.addHandler(logging.NullHandler())
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_redis = Redis()
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class Cache:
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""" Decorator that caches the result of a function
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It works by generating a key given the function signature and uses it to store the result
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of the function on redis, so if the function is called with the same parameters again it
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will be cached and will retrieve the data from redis and will not execute the function.
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It is assumed that the function will returns a dictionary that can be formatted to json.
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"""
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# If caching is enabled
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enabled = settings.CUSTOM_CACHE['enabled']
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# Time to expire, by default a week
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expire = 60 * 60 * 24 * 7
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def __init__(self, function):
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self.function = function
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def __call__(self, *args, **kwargs):
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if not self.enabled:
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_log.info('Cache is disabled, executing function directly')
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return self.function(*args, **kwargs)
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_log.info('Caching function %s with argument list %s and dictionary %s',
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self.function.__name__, args, kwargs)
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key = f'{self.function.__name__}:{self.create_hash_key(args, kwargs)}'
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_log.debug('Resolved key for function is "%s"', key)
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if _redis.exists(key):
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_log.info('Key was in cache')
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result = json.loads(_redis.get(key))
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return result
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_log.info('Key was not in cache')
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result = self.function(*args, **kwargs)
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_redis.set(key, json.dumps(result), ex=self.expire)
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return result
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@staticmethod
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def create_hash_key(args, kwargs):
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"""Crea la key dados unos argumentos arbitrarios"""
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return blake3((str(args) + str(kwargs)).encode('utf-8')).hexdigest()
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