sanic/sanic/websocket.py
2017-02-27 22:35:28 -08:00

68 lines
2.2 KiB
Python

from sanic.exceptions import InvalidUsage
from sanic.server import HttpProtocol
from httptools import HttpParserUpgrade
from websockets import handshake, WebSocketCommonProtocol, InvalidHandshake
from websockets import ConnectionClosed # noqa
class WebSocketProtocol(HttpProtocol):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.websocket = None
def connection_timeout(self):
# timeouts make no sense for websocket routes
if self.websocket is None:
super().connection_timeout()
def connection_lost(self, exc):
if self.websocket is not None:
self.websocket.connection_lost(exc)
super().connection_lost(exc)
def data_received(self, data):
if self.websocket is not None:
# pass the data to the websocket protocol
self.websocket.data_received(data)
else:
try:
super().data_received(data)
except HttpParserUpgrade:
# this is okay, it just indicates we've got an upgrade request
pass
def write_response(self, response):
if self.websocket is not None:
# websocket requests do not write a response
self.transport.close()
else:
super().write_response(response)
async def websocket_handshake(self, request):
# let the websockets package do the handshake with the client
headers = []
def get_header(k):
return request.headers.get(k, '')
def set_header(k, v):
headers.append((k, v))
try:
key = handshake.check_request(get_header)
handshake.build_response(set_header, key)
except InvalidHandshake:
raise InvalidUsage('Invalid websocket request')
# write the 101 response back to the client
rv = b'HTTP/1.1 101 Switching Protocols\r\n'
for k, v in headers:
rv += k.encode('utf-8') + b': ' + v.encode('utf-8') + b'\r\n'
rv += b'\r\n'
request.transport.write(rv)
# hook up the websocket protocol
self.websocket = WebSocketCommonProtocol()
self.websocket.connection_made(request.transport)
return self.websocket