def delete(self, key, ignore_missing=False):
with self._lock:
try:
subject = self._pool.pop(key)
except KeyError:
if not ignore_missing:
raise exc.ServiceLookupError(self, key) from None
return
try:
self._delete(subject)
except Exception as e:
self._pool[key] = subject
raise exc.ServiceDeleteError(self, key, subject) from e
def lookup(self, key):
try:
item = self._pool[key]
except KeyError:
raise exc.ServiceLookupError(self, key) from None
return item