def perform_handshake(self, connection, resume=False):
"""Waits for the gateway to say hello then identifies with it and
waits for its READY acknowledgment.
In the process the heartbeat interval and session ID are defined.
Raises:
AssertionError: Unexpected behaviour from the gateway during the handshake.
KeyError: Handshake messages did not contain necessary information.
"""
payload = connection.receive_payload()
assert payload == Payload.HELLO, "First message upon connection was not HELLO."
self.heartbeat_period = payload.data["heartbeat_interval"] / 1000
# Identify
if resume:
payload = Payload.Resume(self.token, self.session_id,
connection.last_seq)
else:
payload = Payload.Identify(self.token, self.OS, self.NAME)
connection.send_payload(payload)
# Get ready
payload = connection.receive_payload()
if payload == Payload.DISPATCH and payload.event_name == "READY":
self.session_id = payload.data["session_id"]
elif payload == Payload.INVALID:
raise InvalidSessionException()
else:
self.process_payload(payload, connection)
def receive_payload(self):
"""Receives a payload packet from the websocket
and stores its sequence number.
Returns:
A Payload object.
"""
packet = self.ws.recv()
self.logger.info("Inc. packet: %s", packet[:1000])
if packet == "":
raise DisconnectionException()
payload = Payload.from_packet(packet)
if payload.seq_number:
self.last_seq = payload.seq_number
return payload
def send_heartbeat(self, connection):
payload = Payload(Payload.HEARTBEAT, data=connection.last_seq)
connection.send_payload(payload)