"""
"""
"""
_app.py
websocket - WebSocket client library for Python
Copyright 2021 engn33r
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
import selectors
import sys
import threading
import time
import traceback
from ._abnf import ABNF
from ._core import WebSocket, getdefaulttimeout
from ._exceptions import *
from . import _logging
__all__ = ["WebSocketApp"]
class Dispatcher:
"""
Dispatcher
"""
def __init__(self, app, ping_timeout):
self.app = app
self.ping_timeout = ping_timeout
def read(self, sock, read_callback, check_callback):
while self.app.keep_running:
sel = selectors.DefaultSelector()
sel.register(self.app.sock.sock, selectors.EVENT_READ)
r = sel.select(self.ping_timeout)
if r:
if not read_callback():
break
check_callback()
sel.close()
class SSLDispatcher:
"""
SSLDispatcher
"""
def __init__(self, app, ping_timeout):
self.app = app
self.ping_timeout = ping_timeout
def read(self, sock, read_callback, check_callback):
while self.app.keep_running:
r = self.select()
if r:
if not read_callback():
break
check_callback()
def select(self):
sock = self.app.sock.sock
if sock.pending():
return [sock,]
sel = selectors.DefaultSelector()
sel.register(sock, selectors.EVENT_READ)
r = sel.select(self.ping_timeout)
sel.close()
if len(r) > 0:
return r[0][0]
class WebSocketApp:
"""
Higher level of APIs are provided. The interface is like JavaScript WebSocket object.
"""
def __init__(self, url, header=None,
on_open=None, on_message=None, on_error=None,
on_close=None, on_ping=None, on_pong=None,
on_cont_message=None,
keep_running=True, get_mask_key=None, cookie=None,
subprotocols=None,
on_data=None, callback_args=[]):
"""
WebSocketApp initialization
Parameters
----------
url: str
Websocket url.
header: list or dict
Custom header for websocket handshake.
on_open: function
Callback object which is called at opening websocket.
on_open has one argument.
The 1st argument is this class object.
on_message: function
Callback object which is called when received data.
on_message has 2 arguments.
The 1st argument is this class object.
The 2nd argument is utf-8 data received from the server.
on_error: function
Callback object which is called when we get error.
on_error has 2 arguments.
The 1st argument is this class object.
The 2nd argument is exception object.
on_close: function
Callback object which is called when connection is closed.
on_close has 3 arguments.
The 1st argument is this class object.
The 2nd argument is close_status_code.
The 3rd argument is close_msg.
on_cont_message: function
Callback object which is called when a continuation
frame is received.
on_cont_message has 3 arguments.
The 1st argument is this class object.
The 2nd argument is utf-8 string which we get from the server.
The 3rd argument is continue flag. if 0, the data continue
to next frame data
on_data: function
Callback object which is called when a message received.
This is called before on_message or on_cont_message,
and then on_message or on_cont_message is called.
on_data has 4 argument.
The 1st argument is this class object.
The 2nd argument is utf-8 string which we get from the server.
The 3rd argument is data type. ABNF.OPCODE_TEXT or ABNF.OPCODE_BINARY will be came.
The 4th argument is continue flag. If 0, the data continue
keep_running: bool
This parameter is obsolete and ignored.
get_mask_key: function
A callable function to get new mask keys, see the
WebSocket.set_mask_key's docstring for more information.
cookie: str
Cookie value.
subprotocols: list
List of available sub protocols. Default is None.
"""
self.url = url
self.header = header if header is not None else []
self.cookie = cookie
self.on_open = on_open
self.on_message = on_message
self.on_data = on_data
self.on_error = on_error
self.on_close = on_close
self.on_ping = on_ping
self.on_pong = on_pong
self.on_cont_message = on_cont_message
self.keep_running = False
self.get_mask_key = get_mask_key
self.sock = None
self.last_ping_tm = 0
self.last_pong_tm = 0
self.subprotocols = subprotocols
self.callback_args = callback_args
def update_args(self, *args):
self.callback_args = args
#print(self.callback_args)
def send(self, data, opcode=ABNF.OPCODE_TEXT):
"""
send message
Parameters
----------
data: str
Message to send. If you set opcode to OPCODE_TEXT,
data must be utf-8 string or unicode.
opcode: int
Operation code of data. Default is OPCODE_TEXT.
"""
if not self.sock or self.sock.send(data, opcode) == 0:
raise WebSocketConnectionClosedException(
"Connection is already closed.")
def close(self, **kwargs):
"""
Close websocket connection.
"""
self.keep_running = False
if self.sock:
self.sock.close(**kwargs)
self.sock = None
def _send_ping(self, interval, event, payload):
while not event.wait(interval):
self.last_ping_tm = time.time()
if self.sock:
try:
self.sock.ping(payload)
except Exception as ex:
_logging.warning("send_ping routine terminated: {}".format(ex))
break
def run_forever(self, sockopt=None, sslopt=None,
ping_interval=0, ping_timeout=None,
ping_payload="",
http_proxy_host=None, http_proxy_port=None,
http_no_proxy=None, http_proxy_auth=None,
skip_utf8_validation=False,
host=None, origin=None, dispatcher=None,
suppress_origin=False, proxy_type=None):
"""
Run event loop for WebSocket framework.
This loop is an infinite loop and is alive while websocket is available.
Parameters
----------
sockopt: tuple
Values for socket.setsockopt.
sockopt must be tuple
and each element is argument of sock.setsockopt.
sslopt: dict
Optional dict object for ssl socket option.
ping_interval: int or float
Automatically send "ping" command
every specified period (in seconds).
If set to 0, no ping is sent periodically.
ping_timeout: int or float
Timeout (in seconds) if the pong message is not received.
ping_payload: str
Payload message to send with each ping.
http_proxy_host: str
HTTP proxy host name.
http_proxy_port: int or str
HTTP proxy port. If not set, set to 80.
http_no_proxy: list
Whitelisted host names that don't use the proxy.
skip_utf8_validation: bool
skip utf8 validation.
host: str
update host header.
origin: str
update origin header.
dispatcher: Dispatcher object
customize reading data from socket.
suppress_origin: bool
suppress outputting origin header.
Returns
-------
teardown: bool
False if caught KeyboardInterrupt, True if other exception was raised during a loop
"""
if ping_timeout is not None and ping_timeout <= 0:
raise WebSocketException("Ensure ping_timeout > 0")
if ping_interval is not None and ping_interval < 0:
raise WebSocketException("Ensure ping_interval >= 0")
if ping_timeout and ping_interval and ping_interval <= ping_timeout:
raise WebSocketException("Ensure ping_interval > ping_timeout")
if not sockopt:
sockopt = []
if not sslopt:
sslopt = {}
if self.sock:
raise WebSocketException("socket is already opened")
thread = None
self.keep_running = True
self.last_ping_tm = 0
self.last_pong_tm = 0
def teardown(close_frame=None):
"""
Tears down the connection.
Parameters
----------
close_frame: ABNF frame
If close_frame is set, the on_close handler is invoked
with the statusCode and reason from the provided frame.
"""
if thread and thread.is_alive():
event.set()
thread.join()
self.keep_running = False
if self.sock:
self.sock.close()
close_status_code, close_reason = self._get_close_args(
close_frame if close_frame else None)
self.sock = None
# Finally call the callback AFTER all teardown is complete
self._callback(self.on_close, close_status_code, close_reason,
self.callback_args)
try:
self.sock = WebSocket(
self.get_mask_key, sockopt=sockopt, sslopt=sslopt,
fire_cont_frame=self.on_cont_message is not None,
skip_utf8_validation=skip_utf8_validation,
enable_multithread=True)
self.sock.settimeout(getdefaulttimeout())
self.sock.connect(
self.url, header=self.header, cookie=self.cookie,
http_proxy_host=http_proxy_host,
http_proxy_port=http_proxy_port, http_no_proxy=http_no_proxy,
http_proxy_auth=http_proxy_auth, subprotocols=self.subprotocols,
host=host, origin=origin, suppress_origin=suppress_origin,
proxy_type=proxy_type)
if not dispatcher:
dispatcher = self.create_dispatcher(ping_timeout)
self._callback(self.on_open, self.callback_args)
if ping_interval:
event = threading.Event()
thread = threading.Thread(
target=self._send_ping, args=(ping_interval, event, ping_payload))
thread.daemon = True
thread.start()
def read():
if not self.keep_running:
return teardown()
op_code, frame = self.sock.recv_data_frame(True)
if op_code == ABNF.OPCODE_CLOSE:
return teardown(frame)
elif op_code == ABNF.OPCODE_PING:
self._callback(self.on_ping, frame.data, self.callback_args)
elif op_code == ABNF.OPCODE_PONG:
self.last_pong_tm = time.time()
self._callback(self.on_pong, frame.data, self.callback_args)
elif op_code == ABNF.OPCODE_CONT and self.on_cont_message:
self._callback(self.on_data, frame.data,
frame.opcode, frame.fin, self.callback_args)
self._callback(self.on_cont_message,
frame.data, frame.fin, self.callback_args)
else:
data = frame.data
if op_code == ABNF.OPCODE_TEXT:
data = data.decode("utf-8")
self._callback(self.on_message, data, self.callback_args)
else:
self._callback(self.on_data, data, frame.opcode, True,
self.callback_args)
return True
def check():
if (ping_timeout):
has_timeout_expired = time.time() - self.last_ping_tm > ping_timeout
has_pong_not_arrived_after_last_ping = self.last_pong_tm - self.last_ping_tm < 0
has_pong_arrived_too_late = self.last_pong_tm - self.last_ping_tm > ping_timeout
if (self.last_ping_tm and
has_timeout_expired and
(has_pong_not_arrived_after_last_ping or has_pong_arrived_too_late)):
raise WebSocketTimeoutException("ping/pong timed out")
return True
dispatcher.read(self.sock.sock, read, check)
except (Exception, KeyboardInterrupt, SystemExit) as e:
self._callback(self.on_error, e, self.callback_args)
if isinstance(e, SystemExit):
# propagate SystemExit further
raise
teardown()
return not isinstance(e, KeyboardInterrupt)
else:
teardown()
return True
def create_dispatcher(self, ping_timeout):
timeout = ping_timeout or 10
if self.sock.is_ssl():
return SSLDispatcher(self, timeout)
return Dispatcher(self, timeout)
def _get_close_args(self, close_frame):
"""
_get_close_args extracts the close code and reason from the close body
if it exists (RFC6455 says WebSocket Connection Close Code is optional)
"""
# Need to catch the case where close_frame is None
# Otherwise the following if statement causes an error
if not self.on_close or not close_frame:
return [None, None]
# Extract close frame status code
if close_frame.data and len(close_frame.data) >= 2:
close_status_code = 256 * close_frame.data[0] + close_frame.data[1]
reason = close_frame.data[2:].decode('utf-8')
return [close_status_code, reason]
else:
# Most likely reached this because len(close_frame_data.data) < 2
return [None, None]
def _callback(self, callback, *args):
if callback:
try:
callback(self, *args)
except Exception as e:
_logging.error("error from callback {}: {}".format(callback, e))
if self.on_error:
self.on_error(self, e)