def start(self, known_ids=None):
"""Subscribes to state delta events, and then waits to receive deltas.
Sends any events received to delta handlers.
"""
if not known_ids:
known_ids = [NULL_BLOCK_ID]
self._stream.wait_for_ready()
LOGGER.debug('Subscribing to state delta events')
block_sub = EventSubscription(event_type='sawtooth/block-commit')
delta_sub = EventSubscription(
event_type='sawtooth/state-delta',
filters=[
EventFilter(key='address',
match_string='^{}.*'.format(NAMESPACE),
filter_type=EventFilter.REGEX_ANY)
])
request = ClientEventsSubscribeRequest(
last_known_block_ids=known_ids,
subscriptions=[block_sub, delta_sub])
response_future = self._stream.send(
Message.CLIENT_EVENTS_SUBSCRIBE_REQUEST,
request.SerializeToString())
response = ClientEventsSubscribeResponse()
response.ParseFromString(response_future.result().content)
# Forked all the way back to genesis, restart with no known_ids
if (response.status == ClientEventsSubscribeResponse.UNKNOWN_BLOCK
and known_ids):
return self.start()
if response.status != ClientEventsSubscribeResponse.OK:
raise RuntimeError('Subscription failed with status: {}'.format(
ClientEventsSubscribeResponse.Status.Name(response.status)))
self._is_active = True
LOGGER.debug('Successfully subscribed to state delta events')
while self._is_active:
message_future = self._stream.receive()
event_list = EventList()
event_list.ParseFromString(message_future.result().content)
for handler in self._event_handlers:
handler(event_list.events)
def subscribe_to_event(self):
LOGGER.info("Subscribing to event {}".format(self._event))
done_sub = EventSubscription(event_type=self._event)
request = ClientEventsSubscribeRequest(subscriptions=[done_sub])
response_future = self._stream.send(
Message.CLIENT_EVENTS_SUBSCRIBE_REQUEST,
request.SerializeToString())
sub_response = ClientEventsSubscribeResponse()
sub_response.ParseFromString(response_future.result().content)
if sub_response.status == ClientEventsSubscribeResponse.OK:
self._is_active = True
LOGGER.info('Subscription with response {}'.format(
sub_response.status))
else:
LOGGER.error('Could not Subscribe to event')
raise SubscriberError()
def listen_to_event(self):
self._stream.wait_for_ready()
# Step 1: Construct a Subscription
block_sub = EventSubscription(event_type='sawtooth/block-commit')
# Step 2: Submit the Event Subscription
request = ClientEventsSubscribeRequest(subscriptions=[block_sub])
response_future = self._stream.send(
Message.CLIENT_EVENTS_SUBSCRIBE_REQUEST,
request.SerializeToString())
response = ClientEventsSubscribeResponse()
response.ParseFromString(response_future.result().content)
# Listen for events in an infinite loop
LOGGER.warning("Listening to events.")
while True:
msg = self._stream.receive()
event_list = EventList()
event_list.ParseFromString(msg.result().content)
for handler in self._event_handlers:
handler(event_list.events)