django1/django/core/cache/backends/memcached.py

74 lines
2.3 KiB
Python

"Memcached cache backend"
from django.core.cache.backends.base import BaseCache, InvalidCacheBackendError
from django.utils.encoding import smart_unicode, smart_str
try:
import cmemcache as memcache
except ImportError:
try:
import memcache
except:
raise InvalidCacheBackendError("Memcached cache backend requires either the 'memcache' or 'cmemcache' library")
class CacheClass(BaseCache):
def __init__(self, server, params):
BaseCache.__init__(self, params)
self._cache = memcache.Client(server.split(';'))
def add(self, key, value, timeout=0):
if isinstance(value, unicode):
value = value.encode('utf-8')
return self._cache.add(smart_str(key), value, timeout or self.default_timeout)
def get(self, key, default=None):
val = self._cache.get(smart_str(key))
if val is None:
return default
else:
if isinstance(val, basestring):
return smart_unicode(val)
else:
return val
def set(self, key, value, timeout=0):
if isinstance(value, unicode):
value = value.encode('utf-8')
self._cache.set(smart_str(key), value, timeout or self.default_timeout)
def delete(self, key):
self._cache.delete(smart_str(key))
def get_many(self, keys):
return self._cache.get_multi(map(smart_str,keys))
def close(self, **kwargs):
self._cache.disconnect_all()
def incr(self, key, delta=1):
try:
val = self._cache.incr(key, delta)
# python-memcache responds to incr on non-existent keys by
# raising a ValueError. Cmemcache returns None. In both
# cases, we should raise a ValueError though.
except ValueError:
val = None
if val is None:
raise ValueError("Key '%s' not found" % key)
return val
def decr(self, key, delta=1):
try:
val = self._cache.decr(key, delta)
# python-memcache responds to decr on non-existent keys by
# raising a ValueError. Cmemcache returns None. In both
# cases, we should raise a ValueError though.
except ValueError:
val = None
if val is None:
raise ValueError("Key '%s' not found" % key)
return val