import memcache
from myghty.synchronization import *
from myghty.container import NamespaceManager,Container
import sys
class MemcachedNamespaceManager(NamespaceManager):
def __init__(self, context, namespace, url, **params):
NamespaceManager.__init__(self, context, namespace, **params)
self.mc = memcache.Client([url], debug=0)
# memcached does its own locking. override our own stuff
def do_acquire_read_lock(self): pass
def do_release_read_lock(self): pass
def do_acquire_write_lock(self, wait = True): return True
def do_release_write_lock(self): pass
# override open/close to do nothing, keep memcache connection open as long
# as possible
def open(self, *args, **params):pass
def close(self, *args, **params):pass
def __getitem__(self, key):
value = self.mc.get(self.namespace + "_" + key)
if value is None:
raise KeyError(key)
return value
def __contains__(self, key):
return self.mc.get(self.namespace + "_" + key) is not None
def has_key(self, key):
return self.mc.get(self.namespace + "_" + key) is not None
def __setitem__(self, key, value):
keys = self.mc.get(self.namespace + ':keys')
if keys is None:
keys = {}
keys[key] = True
self.mc.set(self.namespace + ':keys', keys)
self.mc.set(self.namespace + "_" + key, value)
def __delitem__(self, key):
keys = self.mc.get(self.namespace + ':keys')
try:
del keys[key]
self.mc.delete(self.namespace + "_" + key)
self.mc.set(self.namespace + ':keys', keys)
except KeyError:
raise
def do_remove(self):
pass
def keys(self):
keys = self.mc.get(self.namespace + ':keys')
if keys is None:
return []
else:
return keys.keys()
class MemcachedContainer(Container):
def do_init(self, **params):
self.funclock = None
def do_create_namespace_manager(self, context, namespace, url, **params):
return MemcachedNamespaceManager(context, namespace, url, **params)
def lock_createfunc(self, wait = True):
if self.funclock is None:
self.funclock = Synchronizer(identifier =
"memcachedcontainer/funclock/%s" % self.namespacemanager.namespace,
use_files = True, lock_dir = self.namespacemanager.lock_dir)
return self.funclock.acquire_write_lock(wait)
def unlock_createfunc(self):
self.funclock.release_write_lock()
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