class Registration(object):
"""An object that registers a znode with ZooKeeper."""
def __init__(self, zk, path, data=None, state=True):
# Create our logger
self.log = logging.getLogger('%s.Registration.%s' % (__name__, path))
# Set our local variables
self._zk = zk
self._path = path
self._state = state
# Store both encdoed-string and decoded-dict versions of our 'data'
# for comparison purposes later.
self._data = data
self._encoded_data = funcs.encode(data)
self._decoded_data = funcs.decode(self._encoded_data)
# Make sure that we have a watcher on the path we care about
self._watcher = Watcher(self._zk,
path=self._path,
watch_children=False,
callback=self._update)
def data(self):
"""Returns live node data from Watcher object."""
return self._watcher.data()
def get(self):
"""Returns live node information from Watcher object."""
return self._watcher.get()
def set_data(self, data):
"""Sets self._data.
Args:
data: String or Dict of data to register with this object."""
if not data == self._data:
self._data = data
self._encoded_data = funcs.encode(data)
self._decoded_data = funcs.decode(self._encoded_data)
self._update_data()
def _update_data(self):
try:
self._zk.retry(self._zk.set, self._path, value=self._encoded_data)
self.log.debug('Updated with data: %s' % self._encoded_data)
except kazoo.exceptions.NoAuthError, e:
self.log.error('No authorization to set node.')
pass
except Exception, e:
self.log.error('Received exception. Moving on, will re-attempt '
'when Watcher notifies us of a state change: %s '
% e)
pass
