mirror of
https://github.com/jazzband/django-constance.git
synced 2026-04-27 18:24:51 +00:00
93 lines
2.7 KiB
Python
93 lines
2.7 KiB
Python
from pickle import loads, dumps
|
|
from threading import RLock
|
|
from time import monotonic
|
|
|
|
from django.core.exceptions import ImproperlyConfigured
|
|
|
|
from . import Backend
|
|
from .. import settings, utils, signals, config
|
|
|
|
|
|
class RedisBackend(Backend):
|
|
|
|
def __init__(self):
|
|
super().__init__()
|
|
self._prefix = settings.REDIS_PREFIX
|
|
connection_cls = settings.REDIS_CONNECTION_CLASS
|
|
if connection_cls is not None:
|
|
self._rd = utils.import_module_attr(connection_cls)()
|
|
else:
|
|
try:
|
|
import redis
|
|
except ImportError:
|
|
raise ImproperlyConfigured(
|
|
"The Redis backend requires redis-py to be installed.")
|
|
if isinstance(settings.REDIS_CONNECTION, str):
|
|
self._rd = redis.from_url(settings.REDIS_CONNECTION)
|
|
else:
|
|
self._rd = redis.Redis(**settings.REDIS_CONNECTION)
|
|
|
|
def add_prefix(self, key):
|
|
return "%s%s" % (self._prefix, key)
|
|
|
|
def get(self, key):
|
|
value = self._rd.get(self.add_prefix(key))
|
|
if value:
|
|
return loads(value)
|
|
return None
|
|
|
|
def mget(self, keys):
|
|
if not keys:
|
|
return
|
|
prefixed_keys = [self.add_prefix(key) for key in keys]
|
|
for key, value in zip(keys, self._rd.mget(prefixed_keys)):
|
|
if value:
|
|
yield key, loads(value)
|
|
|
|
def set(self, key, value):
|
|
old_value = self.get(key)
|
|
self._rd.set(self.add_prefix(key), dumps(value, protocol=settings.REDIS_PICKLE_VERSION))
|
|
signals.config_updated.send(
|
|
sender=config, key=key, old_value=old_value, new_value=value
|
|
)
|
|
|
|
|
|
class CachingRedisBackend(RedisBackend):
|
|
_sentinel = object()
|
|
_lock = RLock()
|
|
|
|
def __init__(self):
|
|
super().__init__()
|
|
self._timeout = settings.REDIS_CACHE_TIMEOUT
|
|
self._cache = {}
|
|
self._sentinel = object()
|
|
|
|
def _has_expired(self, value):
|
|
return value[0] <= monotonic()
|
|
|
|
def _cache_value(self, key, new_value):
|
|
self._cache[key] = (monotonic() + self._timeout, new_value)
|
|
|
|
def get(self, key):
|
|
value = self._cache.get(key, self._sentinel)
|
|
|
|
if value is self._sentinel or self._has_expired(value):
|
|
with self._lock:
|
|
new_value = super().get(key)
|
|
self._cache_value(key, new_value)
|
|
return new_value
|
|
|
|
return value[1]
|
|
|
|
def set(self, key, value):
|
|
with self._lock:
|
|
super().set(key, value)
|
|
self._cache_value(key, value)
|
|
|
|
def mget(self, keys):
|
|
if not keys:
|
|
return
|
|
for key in keys:
|
|
value = self.get(key)
|
|
if value is not None:
|
|
yield key, value
|