--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/core/cache/backends/memcached.py Wed Jun 02 18:57:35 2010 +0200
@@ -0,0 +1,104 @@
+"Memcached cache backend"
+
+import time
+
+from django.core.cache.backends.base import BaseCache, InvalidCacheBackendError
+from django.utils.encoding import smart_unicode, smart_str
+
+try:
+ import cmemcache as memcache
+ import warnings
+ warnings.warn(
+ "Support for the 'cmemcache' library has been deprecated. Please use python-memcached instead.",
+ PendingDeprecationWarning
+ )
+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 _get_memcache_timeout(self, timeout):
+ """
+ Memcached deals with long (> 30 days) timeouts in a special
+ way. Call this function to obtain a safe value for your timeout.
+ """
+ timeout = timeout or self.default_timeout
+ if timeout > 2592000: # 60*60*24*30, 30 days
+ # See http://code.google.com/p/memcached/wiki/FAQ
+ # "You can set expire times up to 30 days in the future. After that
+ # memcached interprets it as a date, and will expire the item after
+ # said date. This is a simple (but obscure) mechanic."
+ #
+ # This means that we have to switch to absolute timestamps.
+ timeout += int(time.time())
+ return timeout
+
+ def add(self, key, value, timeout=0):
+ if isinstance(value, unicode):
+ value = value.encode('utf-8')
+ return self._cache.add(smart_str(key), value, self._get_memcache_timeout(timeout))
+
+ def get(self, key, default=None):
+ val = self._cache.get(smart_str(key))
+ if val is None:
+ return default
+ return val
+
+ def set(self, key, value, timeout=0):
+ self._cache.set(smart_str(key), value, self._get_memcache_timeout(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
+
+ def set_many(self, data, timeout=0):
+ safe_data = {}
+ for key, value in data.items():
+ if isinstance(value, unicode):
+ value = value.encode('utf-8')
+ safe_data[smart_str(key)] = value
+ self._cache.set_multi(safe_data, self._get_memcache_timeout(timeout))
+
+ def delete_many(self, keys):
+ self._cache.delete_multi(map(smart_str, keys))
+
+ def clear(self):
+ self._cache.flush_all()