You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
618 lines
25 KiB
618 lines
25 KiB
import asyncio
|
|
import signal
|
|
import ssl
|
|
import threading
|
|
|
|
try:
|
|
import aiohttp
|
|
except ImportError: # pragma: no cover
|
|
aiohttp = None
|
|
|
|
from . import client
|
|
from . import exceptions
|
|
from . import packet
|
|
from . import payload
|
|
|
|
async_signal_handler_set = False
|
|
|
|
|
|
def async_signal_handler():
|
|
"""SIGINT handler.
|
|
|
|
Disconnect all active async clients.
|
|
"""
|
|
async def _handler():
|
|
asyncio.get_event_loop().stop()
|
|
for c in client.connected_clients[:]:
|
|
if c.is_asyncio_based():
|
|
await c.disconnect()
|
|
else: # pragma: no cover
|
|
pass
|
|
|
|
asyncio.ensure_future(_handler())
|
|
|
|
|
|
class AsyncClient(client.Client):
|
|
"""An Engine.IO client for asyncio.
|
|
|
|
This class implements a fully compliant Engine.IO web client with support
|
|
for websocket and long-polling transports, compatible with the asyncio
|
|
framework on Python 3.5 or newer.
|
|
|
|
:param logger: To enable logging set to ``True`` or pass a logger object to
|
|
use. To disable logging set to ``False``. The default is
|
|
``False``. Note that fatal errors are logged even when
|
|
``logger`` is ``False``.
|
|
:param json: An alternative json module to use for encoding and decoding
|
|
packets. Custom json modules must have ``dumps`` and ``loads``
|
|
functions that are compatible with the standard library
|
|
versions.
|
|
:param request_timeout: A timeout in seconds for requests. The default is
|
|
5 seconds.
|
|
:param http_session: an initialized ``aiohttp.ClientSession`` object to be
|
|
used when sending requests to the server. Use it if
|
|
you need to add special client options such as proxy
|
|
servers, SSL certificates, etc.
|
|
:param ssl_verify: ``True`` to verify SSL certificates, or ``False`` to
|
|
skip SSL certificate verification, allowing
|
|
connections to servers with self signed certificates.
|
|
The default is ``True``.
|
|
:param handle_sigint: Set to ``True`` to automatically handle disconnection
|
|
when the process is interrupted, or to ``False`` to
|
|
leave interrupt handling to the calling application.
|
|
Interrupt handling can only be enabled when the
|
|
client instance is created in the main thread.
|
|
"""
|
|
def is_asyncio_based(self):
|
|
return True
|
|
|
|
async def connect(self, url, headers=None, transports=None,
|
|
engineio_path='engine.io'):
|
|
"""Connect to an Engine.IO server.
|
|
|
|
:param url: The URL of the Engine.IO server. It can include custom
|
|
query string parameters if required by the server.
|
|
:param headers: A dictionary with custom headers to send with the
|
|
connection request.
|
|
:param transports: The list of allowed transports. Valid transports
|
|
are ``'polling'`` and ``'websocket'``. If not
|
|
given, the polling transport is connected first,
|
|
then an upgrade to websocket is attempted.
|
|
:param engineio_path: The endpoint where the Engine.IO server is
|
|
installed. The default value is appropriate for
|
|
most cases.
|
|
|
|
Note: this method is a coroutine.
|
|
|
|
Example usage::
|
|
|
|
eio = engineio.Client()
|
|
await eio.connect('http://localhost:5000')
|
|
"""
|
|
global async_signal_handler_set
|
|
if self.handle_sigint and not async_signal_handler_set and \
|
|
threading.current_thread() == threading.main_thread():
|
|
try:
|
|
asyncio.get_event_loop().add_signal_handler(
|
|
signal.SIGINT, async_signal_handler)
|
|
async_signal_handler_set = True
|
|
except NotImplementedError: # pragma: no cover
|
|
self.logger.warning('Signal handler is unsupported')
|
|
|
|
if self.state != 'disconnected':
|
|
raise ValueError('Client is not in a disconnected state')
|
|
valid_transports = ['polling', 'websocket']
|
|
if transports is not None:
|
|
if isinstance(transports, str):
|
|
transports = [transports]
|
|
transports = [transport for transport in transports
|
|
if transport in valid_transports]
|
|
if not transports:
|
|
raise ValueError('No valid transports provided')
|
|
self.transports = transports or valid_transports
|
|
self.queue = self.create_queue()
|
|
return await getattr(self, '_connect_' + self.transports[0])(
|
|
url, headers or {}, engineio_path)
|
|
|
|
async def wait(self):
|
|
"""Wait until the connection with the server ends.
|
|
|
|
Client applications can use this function to block the main thread
|
|
during the life of the connection.
|
|
|
|
Note: this method is a coroutine.
|
|
"""
|
|
if self.read_loop_task:
|
|
await self.read_loop_task
|
|
|
|
async def send(self, data):
|
|
"""Send a message to a client.
|
|
|
|
:param data: The data to send to the client. Data can be of type
|
|
``str``, ``bytes``, ``list`` or ``dict``. If a ``list``
|
|
or ``dict``, the data will be serialized as JSON.
|
|
|
|
Note: this method is a coroutine.
|
|
"""
|
|
await self._send_packet(packet.Packet(packet.MESSAGE, data=data))
|
|
|
|
async def disconnect(self, abort=False):
|
|
"""Disconnect from the server.
|
|
|
|
:param abort: If set to ``True``, do not wait for background tasks
|
|
associated with the connection to end.
|
|
|
|
Note: this method is a coroutine.
|
|
"""
|
|
if self.state == 'connected':
|
|
await self._send_packet(packet.Packet(packet.CLOSE))
|
|
await self.queue.put(None)
|
|
self.state = 'disconnecting'
|
|
await self._trigger_event('disconnect', run_async=False)
|
|
if self.current_transport == 'websocket':
|
|
await self.ws.close()
|
|
if not abort:
|
|
await self.read_loop_task
|
|
self.state = 'disconnected'
|
|
try:
|
|
client.connected_clients.remove(self)
|
|
except ValueError: # pragma: no cover
|
|
pass
|
|
self._reset()
|
|
|
|
def start_background_task(self, target, *args, **kwargs):
|
|
"""Start a background task.
|
|
|
|
This is a utility function that applications can use to start a
|
|
background task.
|
|
|
|
:param target: the target function to execute.
|
|
:param args: arguments to pass to the function.
|
|
:param kwargs: keyword arguments to pass to the function.
|
|
|
|
The return value is a ``asyncio.Task`` object.
|
|
"""
|
|
return asyncio.ensure_future(target(*args, **kwargs))
|
|
|
|
async def sleep(self, seconds=0):
|
|
"""Sleep for the requested amount of time.
|
|
|
|
Note: this method is a coroutine.
|
|
"""
|
|
return await asyncio.sleep(seconds)
|
|
|
|
def create_queue(self):
|
|
"""Create a queue object."""
|
|
q = asyncio.Queue()
|
|
q.Empty = asyncio.QueueEmpty
|
|
return q
|
|
|
|
def create_event(self):
|
|
"""Create an event object."""
|
|
return asyncio.Event()
|
|
|
|
def __del__(self): # pragma: no cover
|
|
# try to close the aiohttp session if it is still open
|
|
if self.http and not self.http.closed:
|
|
try:
|
|
loop = asyncio.get_event_loop()
|
|
if loop.is_running():
|
|
loop.ensure_future(self.http.close())
|
|
else:
|
|
loop.run_until_complete(self.http.close())
|
|
except:
|
|
pass
|
|
|
|
async def _connect_polling(self, url, headers, engineio_path):
|
|
"""Establish a long-polling connection to the Engine.IO server."""
|
|
if aiohttp is None: # pragma: no cover
|
|
self.logger.error('aiohttp not installed -- cannot make HTTP '
|
|
'requests!')
|
|
return
|
|
self.base_url = self._get_engineio_url(url, engineio_path, 'polling')
|
|
self.logger.info('Attempting polling connection to ' + self.base_url)
|
|
r = await self._send_request(
|
|
'GET', self.base_url + self._get_url_timestamp(), headers=headers,
|
|
timeout=self.request_timeout)
|
|
if r is None or isinstance(r, str):
|
|
self._reset()
|
|
raise exceptions.ConnectionError(
|
|
r or 'Connection refused by the server')
|
|
if r.status < 200 or r.status >= 300:
|
|
self._reset()
|
|
try:
|
|
arg = await r.json()
|
|
except aiohttp.ClientError:
|
|
arg = None
|
|
raise exceptions.ConnectionError(
|
|
'Unexpected status code {} in server response'.format(
|
|
r.status), arg)
|
|
try:
|
|
p = payload.Payload(encoded_payload=(await r.read()).decode(
|
|
'utf-8'))
|
|
except ValueError:
|
|
raise exceptions.ConnectionError(
|
|
'Unexpected response from server') from None
|
|
open_packet = p.packets[0]
|
|
if open_packet.packet_type != packet.OPEN:
|
|
raise exceptions.ConnectionError(
|
|
'OPEN packet not returned by server')
|
|
self.logger.info(
|
|
'Polling connection accepted with ' + str(open_packet.data))
|
|
self.sid = open_packet.data['sid']
|
|
self.upgrades = open_packet.data['upgrades']
|
|
self.ping_interval = int(open_packet.data['pingInterval']) / 1000.0
|
|
self.ping_timeout = int(open_packet.data['pingTimeout']) / 1000.0
|
|
self.current_transport = 'polling'
|
|
self.base_url += '&sid=' + self.sid
|
|
|
|
self.state = 'connected'
|
|
client.connected_clients.append(self)
|
|
await self._trigger_event('connect', run_async=False)
|
|
|
|
for pkt in p.packets[1:]:
|
|
await self._receive_packet(pkt)
|
|
|
|
if 'websocket' in self.upgrades and 'websocket' in self.transports:
|
|
# attempt to upgrade to websocket
|
|
if await self._connect_websocket(url, headers, engineio_path):
|
|
# upgrade to websocket succeeded, we're done here
|
|
return
|
|
|
|
self.write_loop_task = self.start_background_task(self._write_loop)
|
|
self.read_loop_task = self.start_background_task(
|
|
self._read_loop_polling)
|
|
|
|
async def _connect_websocket(self, url, headers, engineio_path):
|
|
"""Establish or upgrade to a WebSocket connection with the server."""
|
|
if aiohttp is None: # pragma: no cover
|
|
self.logger.error('aiohttp package not installed')
|
|
return False
|
|
websocket_url = self._get_engineio_url(url, engineio_path,
|
|
'websocket')
|
|
if self.sid:
|
|
self.logger.info(
|
|
'Attempting WebSocket upgrade to ' + websocket_url)
|
|
upgrade = True
|
|
websocket_url += '&sid=' + self.sid
|
|
else:
|
|
upgrade = False
|
|
self.base_url = websocket_url
|
|
self.logger.info(
|
|
'Attempting WebSocket connection to ' + websocket_url)
|
|
|
|
if self.http is None or self.http.closed: # pragma: no cover
|
|
self.http = aiohttp.ClientSession()
|
|
|
|
# extract any new cookies passed in a header so that they can also be
|
|
# sent the the WebSocket route
|
|
cookies = {}
|
|
for header, value in headers.items():
|
|
if header.lower() == 'cookie':
|
|
cookies = dict(
|
|
[cookie.split('=', 1) for cookie in value.split('; ')])
|
|
del headers[header]
|
|
break
|
|
self.http.cookie_jar.update_cookies(cookies)
|
|
|
|
try:
|
|
if not self.ssl_verify:
|
|
ssl_context = ssl.create_default_context()
|
|
ssl_context.check_hostname = False
|
|
ssl_context.verify_mode = ssl.CERT_NONE
|
|
ws = await self.http.ws_connect(
|
|
websocket_url + self._get_url_timestamp(),
|
|
headers=headers, ssl=ssl_context)
|
|
else:
|
|
ws = await self.http.ws_connect(
|
|
websocket_url + self._get_url_timestamp(),
|
|
headers=headers)
|
|
except (aiohttp.client_exceptions.WSServerHandshakeError,
|
|
aiohttp.client_exceptions.ServerConnectionError,
|
|
aiohttp.client_exceptions.ClientConnectionError):
|
|
if upgrade:
|
|
self.logger.warning(
|
|
'WebSocket upgrade failed: connection error')
|
|
return False
|
|
else:
|
|
raise exceptions.ConnectionError('Connection error')
|
|
if upgrade:
|
|
p = packet.Packet(packet.PING, data='probe').encode()
|
|
try:
|
|
await ws.send_str(p)
|
|
except Exception as e: # pragma: no cover
|
|
self.logger.warning(
|
|
'WebSocket upgrade failed: unexpected send exception: %s',
|
|
str(e))
|
|
return False
|
|
try:
|
|
p = (await ws.receive()).data
|
|
except Exception as e: # pragma: no cover
|
|
self.logger.warning(
|
|
'WebSocket upgrade failed: unexpected recv exception: %s',
|
|
str(e))
|
|
return False
|
|
pkt = packet.Packet(encoded_packet=p)
|
|
if pkt.packet_type != packet.PONG or pkt.data != 'probe':
|
|
self.logger.warning(
|
|
'WebSocket upgrade failed: no PONG packet')
|
|
return False
|
|
p = packet.Packet(packet.UPGRADE).encode()
|
|
try:
|
|
await ws.send_str(p)
|
|
except Exception as e: # pragma: no cover
|
|
self.logger.warning(
|
|
'WebSocket upgrade failed: unexpected send exception: %s',
|
|
str(e))
|
|
return False
|
|
self.current_transport = 'websocket'
|
|
self.logger.info('WebSocket upgrade was successful')
|
|
else:
|
|
try:
|
|
p = (await ws.receive()).data
|
|
except Exception as e: # pragma: no cover
|
|
raise exceptions.ConnectionError(
|
|
'Unexpected recv exception: ' + str(e))
|
|
open_packet = packet.Packet(encoded_packet=p)
|
|
if open_packet.packet_type != packet.OPEN:
|
|
raise exceptions.ConnectionError('no OPEN packet')
|
|
self.logger.info(
|
|
'WebSocket connection accepted with ' + str(open_packet.data))
|
|
self.sid = open_packet.data['sid']
|
|
self.upgrades = open_packet.data['upgrades']
|
|
self.ping_interval = int(open_packet.data['pingInterval']) / 1000.0
|
|
self.ping_timeout = int(open_packet.data['pingTimeout']) / 1000.0
|
|
self.current_transport = 'websocket'
|
|
|
|
self.state = 'connected'
|
|
client.connected_clients.append(self)
|
|
await self._trigger_event('connect', run_async=False)
|
|
|
|
self.ws = ws
|
|
self.write_loop_task = self.start_background_task(self._write_loop)
|
|
self.read_loop_task = self.start_background_task(
|
|
self._read_loop_websocket)
|
|
return True
|
|
|
|
async def _receive_packet(self, pkt):
|
|
"""Handle incoming packets from the server."""
|
|
packet_name = packet.packet_names[pkt.packet_type] \
|
|
if pkt.packet_type < len(packet.packet_names) else 'UNKNOWN'
|
|
self.logger.info(
|
|
'Received packet %s data %s', packet_name,
|
|
pkt.data if not isinstance(pkt.data, bytes) else '<binary>')
|
|
if pkt.packet_type == packet.MESSAGE:
|
|
await self._trigger_event('message', pkt.data, run_async=True)
|
|
elif pkt.packet_type == packet.PING:
|
|
await self._send_packet(packet.Packet(packet.PONG, pkt.data))
|
|
elif pkt.packet_type == packet.CLOSE:
|
|
await self.disconnect(abort=True)
|
|
elif pkt.packet_type == packet.NOOP:
|
|
pass
|
|
else:
|
|
self.logger.error('Received unexpected packet of type %s',
|
|
pkt.packet_type)
|
|
|
|
async def _send_packet(self, pkt):
|
|
"""Queue a packet to be sent to the server."""
|
|
if self.state != 'connected':
|
|
return
|
|
await self.queue.put(pkt)
|
|
self.logger.info(
|
|
'Sending packet %s data %s',
|
|
packet.packet_names[pkt.packet_type],
|
|
pkt.data if not isinstance(pkt.data, bytes) else '<binary>')
|
|
|
|
async def _send_request(
|
|
self, method, url, headers=None, body=None,
|
|
timeout=None): # pragma: no cover
|
|
if self.http is None or self.http.closed:
|
|
self.http = aiohttp.ClientSession()
|
|
http_method = getattr(self.http, method.lower())
|
|
|
|
try:
|
|
if not self.ssl_verify:
|
|
return await http_method(
|
|
url, headers=headers, data=body,
|
|
timeout=aiohttp.ClientTimeout(total=timeout), ssl=False)
|
|
else:
|
|
return await http_method(
|
|
url, headers=headers, data=body,
|
|
timeout=aiohttp.ClientTimeout(total=timeout))
|
|
|
|
except (aiohttp.ClientError, asyncio.TimeoutError) as exc:
|
|
self.logger.info('HTTP %s request to %s failed with error %s.',
|
|
method, url, exc)
|
|
return str(exc)
|
|
|
|
async def _trigger_event(self, event, *args, **kwargs):
|
|
"""Invoke an event handler."""
|
|
run_async = kwargs.pop('run_async', False)
|
|
ret = None
|
|
if event in self.handlers:
|
|
if asyncio.iscoroutinefunction(self.handlers[event]) is True:
|
|
if run_async:
|
|
return self.start_background_task(self.handlers[event],
|
|
*args)
|
|
else:
|
|
try:
|
|
ret = await self.handlers[event](*args)
|
|
except asyncio.CancelledError: # pragma: no cover
|
|
pass
|
|
except:
|
|
self.logger.exception(event + ' async handler error')
|
|
if event == 'connect':
|
|
# if connect handler raised error we reject the
|
|
# connection
|
|
return False
|
|
else:
|
|
if run_async:
|
|
async def async_handler():
|
|
return self.handlers[event](*args)
|
|
|
|
return self.start_background_task(async_handler)
|
|
else:
|
|
try:
|
|
ret = self.handlers[event](*args)
|
|
except:
|
|
self.logger.exception(event + ' handler error')
|
|
if event == 'connect':
|
|
# if connect handler raised error we reject the
|
|
# connection
|
|
return False
|
|
return ret
|
|
|
|
async def _read_loop_polling(self):
|
|
"""Read packets by polling the Engine.IO server."""
|
|
while self.state == 'connected':
|
|
self.logger.info(
|
|
'Sending polling GET request to ' + self.base_url)
|
|
r = await self._send_request(
|
|
'GET', self.base_url + self._get_url_timestamp(),
|
|
timeout=max(self.ping_interval, self.ping_timeout) + 5)
|
|
if r is None or isinstance(r, str):
|
|
self.logger.warning(
|
|
r or 'Connection refused by the server, aborting')
|
|
await self.queue.put(None)
|
|
break
|
|
if r.status < 200 or r.status >= 300:
|
|
self.logger.warning('Unexpected status code %s in server '
|
|
'response, aborting', r.status)
|
|
await self.queue.put(None)
|
|
break
|
|
try:
|
|
p = payload.Payload(encoded_payload=(await r.read()).decode(
|
|
'utf-8'))
|
|
except ValueError:
|
|
self.logger.warning(
|
|
'Unexpected packet from server, aborting')
|
|
await self.queue.put(None)
|
|
break
|
|
for pkt in p.packets:
|
|
await self._receive_packet(pkt)
|
|
|
|
self.logger.info('Waiting for write loop task to end')
|
|
await self.write_loop_task
|
|
if self.state == 'connected':
|
|
await self._trigger_event('disconnect', run_async=False)
|
|
try:
|
|
client.connected_clients.remove(self)
|
|
except ValueError: # pragma: no cover
|
|
pass
|
|
self._reset()
|
|
self.logger.info('Exiting read loop task')
|
|
|
|
async def _read_loop_websocket(self):
|
|
"""Read packets from the Engine.IO WebSocket connection."""
|
|
while self.state == 'connected':
|
|
p = None
|
|
try:
|
|
p = await asyncio.wait_for(
|
|
self.ws.receive(),
|
|
timeout=self.ping_interval + self.ping_timeout)
|
|
p = p.data
|
|
if p is None: # pragma: no cover
|
|
await self.queue.put(None)
|
|
break # the connection is broken
|
|
except asyncio.TimeoutError:
|
|
self.logger.warning(
|
|
'Server has stopped communicating, aborting')
|
|
await self.queue.put(None)
|
|
break
|
|
except aiohttp.client_exceptions.ServerDisconnectedError:
|
|
self.logger.info(
|
|
'Read loop: WebSocket connection was closed, aborting')
|
|
await self.queue.put(None)
|
|
break
|
|
except Exception as e:
|
|
self.logger.info(
|
|
'Unexpected error receiving packet: "%s", aborting',
|
|
str(e))
|
|
await self.queue.put(None)
|
|
break
|
|
try:
|
|
pkt = packet.Packet(encoded_packet=p)
|
|
except Exception as e: # pragma: no cover
|
|
self.logger.info(
|
|
'Unexpected error decoding packet: "%s", aborting', str(e))
|
|
await self.queue.put(None)
|
|
break
|
|
await self._receive_packet(pkt)
|
|
|
|
self.logger.info('Waiting for write loop task to end')
|
|
await self.write_loop_task
|
|
if self.state == 'connected':
|
|
await self._trigger_event('disconnect', run_async=False)
|
|
try:
|
|
client.connected_clients.remove(self)
|
|
except ValueError: # pragma: no cover
|
|
pass
|
|
self._reset()
|
|
self.logger.info('Exiting read loop task')
|
|
|
|
async def _write_loop(self):
|
|
"""This background task sends packages to the server as they are
|
|
pushed to the send queue.
|
|
"""
|
|
while self.state == 'connected':
|
|
# to simplify the timeout handling, use the maximum of the
|
|
# ping interval and ping timeout as timeout, with an extra 5
|
|
# seconds grace period
|
|
timeout = max(self.ping_interval, self.ping_timeout) + 5
|
|
packets = None
|
|
try:
|
|
packets = [await asyncio.wait_for(self.queue.get(), timeout)]
|
|
except (self.queue.Empty, asyncio.TimeoutError,
|
|
asyncio.CancelledError):
|
|
self.logger.error('packet queue is empty, aborting')
|
|
break
|
|
if packets == [None]:
|
|
self.queue.task_done()
|
|
packets = []
|
|
else:
|
|
while True:
|
|
try:
|
|
packets.append(self.queue.get_nowait())
|
|
except self.queue.Empty:
|
|
break
|
|
if packets[-1] is None:
|
|
packets = packets[:-1]
|
|
self.queue.task_done()
|
|
break
|
|
if not packets:
|
|
# empty packet list returned -> connection closed
|
|
break
|
|
if self.current_transport == 'polling':
|
|
p = payload.Payload(packets=packets)
|
|
r = await self._send_request(
|
|
'POST', self.base_url, body=p.encode(),
|
|
headers={'Content-Type': 'text/plain'},
|
|
timeout=self.request_timeout)
|
|
for pkt in packets:
|
|
self.queue.task_done()
|
|
if r is None or isinstance(r, str):
|
|
self.logger.warning(
|
|
r or 'Connection refused by the server, aborting')
|
|
break
|
|
if r.status < 200 or r.status >= 300:
|
|
self.logger.warning('Unexpected status code %s in server '
|
|
'response, aborting', r.status)
|
|
self._reset()
|
|
break
|
|
else:
|
|
# websocket
|
|
try:
|
|
for pkt in packets:
|
|
if pkt.binary:
|
|
await self.ws.send_bytes(pkt.encode())
|
|
else:
|
|
await self.ws.send_str(pkt.encode())
|
|
self.queue.task_done()
|
|
except (aiohttp.client_exceptions.ServerDisconnectedError,
|
|
BrokenPipeError, OSError):
|
|
self.logger.info(
|
|
'Write loop: WebSocket connection was closed, '
|
|
'aborting')
|
|
break
|
|
self.logger.info('Exiting write loop task')
|