"""
"""
"""
websocket - WebSocket client library for Python
Copyright (C) 2010 Hiroki Ohtani(liris)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""
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]
[docs]class WebSocketApp(object):
"""
Higher level of APIs are provided. The interface is like JavaScript WebSocket object.
"""
[docs] 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):
"""
WebSocketApp initialization
Parameters
----------
url: <type>
websocket url.
header: list or dict
custom header for websocket handshake.
on_open: <type>
callable object which is called at opening websocket.
this function has one argument. The argument is this class object.
on_message: <type>
callable 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 string which we get from the server.
on_error: <type>
callable 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: <type>
callable object which is called when closed the connection.
this function has one argument. The argument is this class object.
on_cont_message: <type>
callback object which is called when receive continued
frame data.
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: <type>
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: <type>
this parameter is obsolete and ignored.
get_mask_key: func
a callable to produce new mask keys,
see the WebSocket.set_mask_key's docstring for more information
cookie: str
cookie value.
subprotocols: <type>
array 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
[docs] def send(self, data, opcode=ABNF.OPCODE_TEXT):
"""
send message
Parameters
----------
data: <type>
Message to send. If you set opcode to OPCODE_TEXT,
data must be utf-8 string or unicode.
opcode: <type>
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.")
[docs] 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
[docs] 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, not send automatically.
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: <type>
http proxy host name.
http_proxy_port: <type>
http proxy port. If not set, set to 80.
http_no_proxy: <type>
host names, which doesn't use proxy.
skip_utf8_validation: bool
skip utf8 validation.
host: str
update host header.
origin: str
update origin header.
dispatcher: <type>
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.
If close_frame is set, we will invoke the on_close handler with the
statusCode and reason from there.
"""
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._callback(self.on_close, close_status_code, close_reason)
self.sock = None
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 if ping_interval else False)
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)
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)
elif op_code == ABNF.OPCODE_PONG:
self.last_pong_tm = time.time()
self._callback(self.on_pong, frame.data)
elif op_code == ABNF.OPCODE_CONT and self.on_cont_message:
self._callback(self.on_data, frame.data,
frame.opcode, frame.fin)
self._callback(self.on_cont_message,
frame.data, frame.fin)
else:
data = frame.data
if op_code == ABNF.OPCODE_TEXT:
data = data.decode("utf-8")
self._callback(self.on_data, data, frame.opcode, True)
self._callback(self.on_message, data)
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)
if isinstance(e, SystemExit):
# propagate SystemExit further
raise
teardown()
return not isinstance(e, KeyboardInterrupt)
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 _logging.isEnabledForDebug():
_, _, tb = sys.exc_info()
traceback.print_tb(tb)