from typing import Iterable
from redis import Redis, StrictRedis
from ..cache_keys import decode, encode
from . import BaseCache, BaseStorage, get_valid_kwargs
[docs]class RedisCache(BaseCache):
"""Redis cache backend.
Args:
namespace: redis namespace (default: ``'requests-cache'``)
connection: Redis connection instance to use instead of creating a new one
kwargs: Additional keyword arguments for :py:class:`redis.client.Redis`
"""
def __init__(self, namespace='http_cache', connection: Redis = None, **kwargs):
super().__init__(**kwargs)
self.responses = RedisDict(namespace, 'responses', connection=connection, **kwargs)
self.redirects = RedisDict(
namespace, 'redirects', connection=self.responses.connection, **kwargs
)
[docs]class RedisDict(BaseStorage):
"""A dictionary-like interface for redis key-value store.
Notes:
* In order to deal with how redis stores data/keys, all keys and data are pickled.
* The actual key name on the redis server will be ``namespace:collection_name``.
Args:
namespace: Redis namespace
collection_name: Name of the Redis hash map
connection: (optional) Redis connection instance to use instead of creating a new one
kwargs: Additional keyword arguments for :py:class:`redis.client.Redis`
"""
def __init__(self, namespace, collection_name='http_cache', connection=None, **kwargs):
super().__init__(**kwargs)
connection_kwargs = get_valid_kwargs(Redis, kwargs)
self.connection = connection or StrictRedis(**connection_kwargs)
self._self_key = ':'.join([namespace, collection_name])
def __getitem__(self, key):
result = self.connection.hget(self._self_key, encode(key))
if result is None:
raise KeyError
return self.serializer.loads(result)
def __setitem__(self, key, item):
self.connection.hset(self._self_key, encode(key), self.serializer.dumps(item))
def __delitem__(self, key):
if not self.connection.hdel(self._self_key, encode(key)):
raise KeyError
def __len__(self):
return self.connection.hlen(self._self_key)
def __iter__(self):
for key in self.connection.hkeys(self._self_key):
yield decode(key)
[docs] def bulk_delete(self, keys: Iterable[str]):
"""Delete multiple keys from the cache. Does not raise errors for missing keys."""
if keys:
self.connection.hdel(self._self_key, *[encode(key) for key in keys])
[docs] def clear(self):
self.connection.delete(self._self_key)