sanic/sanic/websocket.py
2018-10-17 21:20:16 -07:00

106 lines
3.7 KiB
Python

from httptools import HttpParserUpgrade
from websockets import ConnectionClosed # noqa
from websockets import InvalidHandshake, WebSocketCommonProtocol, handshake
from sanic.exceptions import InvalidUsage
from sanic.server import HttpProtocol
class WebSocketProtocol(HttpProtocol):
def __init__(
self,
*args,
websocket_timeout=10,
websocket_max_size=None,
websocket_max_queue=None,
websocket_read_limit=2 ** 16,
websocket_write_limit=2 ** 16,
**kwargs
):
super().__init__(*args, **kwargs)
self.websocket = None
self.websocket_timeout = websocket_timeout
self.websocket_max_size = websocket_max_size
self.websocket_max_queue = websocket_max_queue
self.websocket_read_limit = websocket_read_limit
self.websocket_write_limit = websocket_write_limit
# timeouts make no sense for websocket routes
def request_timeout_callback(self):
if self.websocket is None:
super().request_timeout_callback()
def response_timeout_callback(self):
if self.websocket is None:
super().response_timeout_callback()
def keep_alive_timeout_callback(self):
if self.websocket is None:
super().keep_alive_timeout_callback()
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, subprotocols=None):
# let the websockets package do the handshake with the client
headers = {}
try:
key = handshake.check_request(request.headers)
handshake.build_response(headers, key)
except InvalidHandshake:
raise InvalidUsage("Invalid websocket request")
subprotocol = None
if subprotocols and "Sec-Websocket-Protocol" in request.headers:
# select a subprotocol
client_subprotocols = [
p.strip()
for p in request.headers["Sec-Websocket-Protocol"].split(",")
]
for p in client_subprotocols:
if p in subprotocols:
subprotocol = p
headers["Sec-Websocket-Protocol"] = subprotocol
break
# write the 101 response back to the client
rv = b"HTTP/1.1 101 Switching Protocols\r\n"
for k, v in headers.items():
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(
timeout=self.websocket_timeout,
max_size=self.websocket_max_size,
max_queue=self.websocket_max_queue,
read_limit=self.websocket_read_limit,
write_limit=self.websocket_write_limit,
)
self.websocket.subprotocol = subprotocol
self.websocket.connection_made(request.transport)
self.websocket.connection_open()
return self.websocket