import inspect
import selectors
import socket
import threading
import time
from typing import Any, Callable, Optional, Union
from . import _logging
from ._abnf import ABNF
from ._core import WebSocket, getdefaulttimeout
from ._exceptions import (
WebSocketConnectionClosedException,
WebSocketException,
WebSocketTimeoutException,
)
from ._ssl_compat import SSLEOFError
from ._url import parse_url
"""
_app.py
websocket - WebSocket client library for Python
Copyright 2024 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.
"""
__all__ = ["WebSocketApp"]
RECONNECT = 0
def setReconnect(reconnectInterval: int) -> None:
global RECONNECT
RECONNECT = reconnectInterval
class DispatcherBase:
"""
DispatcherBase
"""
def __init__(self, app: Any, ping_timeout: Union[float, int, None]) -> None:
self.app = app
self.ping_timeout = ping_timeout
def timeout(self, seconds: Union[float, int, None], callback: Callable) -> None:
time.sleep(seconds)
callback()
def reconnect(self, seconds: int, reconnector: Callable) -> None:
try:
_logging.info(
f"reconnect() - retrying in {seconds} seconds [{len(inspect.stack())} frames in stack]"
)
time.sleep(seconds)
reconnector(reconnecting=True)
except KeyboardInterrupt as e:
_logging.info(f"User exited {e}")
raise e
class Dispatcher(DispatcherBase):
"""
Dispatcher
"""
def read(
self,
sock: socket.socket,
read_callback: Callable,
check_callback: Callable,
) -> None:
sel = selectors.DefaultSelector()
sel.register(self.app.sock.sock, selectors.EVENT_READ)
try:
while self.app.keep_running:
if sel.select(self.ping_timeout):
if not read_callback():
break
check_callback()
finally:
sel.close()
class SSLDispatcher(DispatcherBase):
"""
SSLDispatcher
"""
def read(
self,
sock: socket.socket,
read_callback: Callable,
check_callback: Callable,
) -> None:
sock = self.app.sock.sock
sel = selectors.DefaultSelector()
sel.register(sock, selectors.EVENT_READ)
try:
while self.app.keep_running:
if self.select(sock, sel):
if not read_callback():
break
check_callback()
finally:
sel.close()
def select(self, sock, sel: selectors.DefaultSelector):
sock = self.app.sock.sock
if sock.pending():
return [
sock,
]
r = sel.select(self.ping_timeout)
if len(r) > 0:
return r[0][0]
class WrappedDispatcher:
"""
WrappedDispatcher
"""
def __init__(self, app, ping_timeout: Union[float, int, None], dispatcher) -> None:
self.app = app
self.ping_timeout = ping_timeout
self.dispatcher = dispatcher
dispatcher.signal(2, dispatcher.abort) # keyboard interrupt
def read(
self,
sock: socket.socket,
read_callback: Callable,
check_callback: Callable,
) -> None:
self.dispatcher.read(sock, read_callback)
self.ping_timeout and self.timeout(self.ping_timeout, check_callback)
def timeout(self, seconds: float, callback: Callable) -> None:
self.dispatcher.timeout(seconds, callback)
def reconnect(self, seconds: int, reconnector: Callable) -> None:
self.timeout(seconds, reconnector)
class WebSocketApp:
"""
Higher level of APIs are provided. The interface is like JavaScript WebSocket object.
"""
def __init__(
self,
url: str,
header: Union[list, dict, Callable, None] = None,
on_open: Optional[Callable[[WebSocket], None]] = None,
on_reconnect: Optional[Callable[[WebSocket], None]] = None,
on_message: Optional[Callable[[WebSocket, Any], None]] = None,
on_error: Optional[Callable[[WebSocket, Any], None]] = None,
on_close: Optional[Callable[[WebSocket, Any, Any], None]] = None,
on_ping: Optional[Callable] = None,
on_pong: Optional[Callable] = None,
on_cont_message: Optional[Callable] = None,
keep_running: bool = True,
get_mask_key: Optional[Callable] = None,
cookie: Optional[str] = None,
subprotocols: Optional[list] = None,
on_data: Optional[Callable] = None,
socket: Optional[socket.socket] = None,
) -> None:
"""
WebSocketApp initialization
Parameters
----------
url: str
Websocket url.
header: list or dict or Callable
Custom header for websocket handshake.
If the parameter is a callable object, it is called just before the connection attempt.
The returned dict or list is used as custom header value.
This could be useful in order to properly setup timestamp dependent headers.
on_open: function
Callback object which is called at opening websocket.
on_open has one argument.
The 1st argument is this class object.
on_reconnect: function
Callback object which is called at reconnecting websocket.
on_reconnect 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.
socket: socket
Pre-initialized stream socket.
"""
self.url = url
self.header = header if header is not None else []
self.cookie = cookie
self.on_open = on_open
self.on_reconnect = on_reconnect
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: Optional[WebSocket] = None
self.last_ping_tm = float(0)
self.last_pong_tm = float(0)
self.ping_thread: Optional[threading.Thread] = None
self.stop_ping: Optional[threading.Event] = None
self.ping_interval = float(0)
self.ping_timeout: Union[float, int, None] = None
self.ping_payload = ""
self.subprotocols = subprotocols
self.prepared_socket = socket
self.has_errored = False
self.has_done_teardown = False
self.has_done_teardown_lock = threading.Lock()
def send(self, data: Union[bytes, str], opcode: int = ABNF.OPCODE_TEXT) -> None:
"""
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 send_text(self, text_data: str) -> None:
"""
Sends UTF-8 encoded text.
"""
if not self.sock or self.sock.send(text_data, ABNF.OPCODE_TEXT) == 0:
raise WebSocketConnectionClosedException("Connection is already closed.")
def send_bytes(self, data: Union[bytes, bytearray]) -> None:
"""
Sends a sequence of bytes.
"""
if not self.sock or self.sock.send(data, ABNF.OPCODE_BINARY) == 0:
raise WebSocketConnectionClosedException("Connection is already closed.")
def close(self, **kwargs) -> None:
"""
Close websocket connection.
"""
self.keep_running = False
if self.sock:
self.sock.close(**kwargs)
self.sock = None
def _start_ping_thread(self) -> None:
self.last_ping_tm = self.last_pong_tm = float(0)
self.stop_ping = threading.Event()
self.ping_thread = threading.Thread(target=self._send_ping)
self.ping_thread.daemon = True
self.ping_thread.start()
def _stop_ping_thread(self) -> None:
if self.stop_ping:
self.stop_ping.set()
if self.ping_thread and self.ping_thread.is_alive():
self.ping_thread.join(3)
self.last_ping_tm = self.last_pong_tm = float(0)
def _send_ping(self) -> None:
if self.stop_ping.wait(self.ping_interval) or self.keep_running is False:
return
while not self.stop_ping.wait(self.ping_interval) and self.keep_running is True:
if self.sock:
self.last_ping_tm = time.time()
try:
_logging.debug("Sending ping")
self.sock.ping(self.ping_payload)
except Exception as e:
_logging.debug(f"Failed to send ping: {e}")
def run_forever(
self,
sockopt: tuple = None,
sslopt: dict = None,
ping_interval: Union[float, int] = 0,
ping_timeout: Union[float, int, None] = None,
ping_payload: str = "",
http_proxy_host: str = None,
http_proxy_port: Union[int, str] = None,
http_no_proxy: list = None,
http_proxy_auth: tuple = None,
http_proxy_timeout: Optional[float] = None,
skip_utf8_validation: bool = False,
host: str = None,
origin: str = None,
dispatcher=None,
suppress_origin: bool = False,
proxy_type: str = None,
reconnect: int = None,
) -> bool:
"""
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.
http_proxy_timeout: int or float
HTTP proxy timeout, default is 60 sec as per python-socks.
http_proxy_auth: tuple
HTTP proxy auth information. tuple of username and password. Default is None.
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.
proxy_type: str
type of proxy from: http, socks4, socks4a, socks5, socks5h
reconnect: int
delay interval when reconnecting
Returns
-------
teardown: bool
False if the `WebSocketApp` is closed or caught KeyboardInterrupt,
True if any other exception was raised during a loop.
"""
if reconnect is None:
reconnect = RECONNECT
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")
self.ping_interval = ping_interval
self.ping_timeout = ping_timeout
self.ping_payload = ping_payload
self.has_done_teardown = False
self.keep_running = True
def teardown(close_frame: ABNF = 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.
"""
# teardown() is called in many code paths to ensure resources are cleaned up and on_close is fired.
# To ensure the work is only done once, we use this bool and lock.
with self.has_done_teardown_lock:
if self.has_done_teardown:
return
self.has_done_teardown = True
self._stop_ping_thread()
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)
def setSock(reconnecting: bool = False) -> None:
if reconnecting and self.sock:
self.sock.shutdown()
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())
try:
header = self.header() if callable(self.header) else self.header
self.sock.connect(
self.url,
header=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,
http_proxy_timeout=http_proxy_timeout,
subprotocols=self.subprotocols,
host=host,
origin=origin,
suppress_origin=suppress_origin,
proxy_type=proxy_type,
socket=self.prepared_socket,
)
_logging.info("Websocket connected")
if self.ping_interval:
self._start_ping_thread()
if reconnecting and self.on_reconnect:
self._callback(self.on_reconnect)
else:
self._callback(self.on_open)
dispatcher.read(self.sock.sock, read, check)
except (
WebSocketConnectionClosedException,
ConnectionRefusedError,
KeyboardInterrupt,
SystemExit,
Exception,
) as e:
handleDisconnect(e, reconnecting)
def read() -> bool:
if not self.keep_running:
return teardown()
try:
op_code, frame = self.sock.recv_data_frame(True)
except (
WebSocketConnectionClosedException,
KeyboardInterrupt,
SSLEOFError,
) as e:
if custom_dispatcher:
return handleDisconnect(e, bool(reconnect))
else:
raise e
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 and not skip_utf8_validation:
data = data.decode("utf-8")
self._callback(self.on_data, data, frame.opcode, True)
self._callback(self.on_message, data)
return True
def check() -> bool:
if self.ping_timeout:
has_timeout_expired = (
time.time() - self.last_ping_tm > self.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 > self.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
def handleDisconnect(
e: Union[
WebSocketConnectionClosedException,
ConnectionRefusedError,
KeyboardInterrupt,
SystemExit,
Exception,
],
reconnecting: bool = False,
) -> bool:
self.has_errored = True
self._stop_ping_thread()
if not reconnecting:
self._callback(self.on_error, e)
if isinstance(e, (KeyboardInterrupt, SystemExit)):
teardown()
# Propagate further
raise
if reconnect:
_logging.info(f"{e} - reconnect")
if custom_dispatcher:
_logging.debug(
f"Calling custom dispatcher reconnect [{len(inspect.stack())} frames in stack]"
)
dispatcher.reconnect(reconnect, setSock)
else:
_logging.error(f"{e} - goodbye")
teardown()
custom_dispatcher = bool(dispatcher)
dispatcher = self.create_dispatcher(
ping_timeout, dispatcher, parse_url(self.url)[3]
)
try:
setSock()
if not custom_dispatcher and reconnect:
while self.keep_running:
_logging.debug(
f"Calling dispatcher reconnect [{len(inspect.stack())} frames in stack]"
)
dispatcher.reconnect(reconnect, setSock)
except (KeyboardInterrupt, Exception) as e:
_logging.info(f"tearing down on exception {e}")
teardown()
finally:
if not custom_dispatcher:
# Ensure teardown was called before returning from run_forever
teardown()
return self.has_errored
def create_dispatcher(
self,
ping_timeout: Union[float, int, None],
dispatcher: Optional[DispatcherBase] = None,
is_ssl: bool = False,
) -> Union[Dispatcher, SSLDispatcher, WrappedDispatcher]:
if dispatcher: # If custom dispatcher is set, use WrappedDispatcher
return WrappedDispatcher(self, ping_timeout, dispatcher)
timeout = ping_timeout or 10
if is_ssl:
return SSLDispatcher(self, timeout)
return Dispatcher(self, timeout)
def _get_close_args(self, close_frame: ABNF) -> list:
"""
_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 * int(close_frame.data[0]) + int(
close_frame.data[1]
)
reason = close_frame.data[2:]
if isinstance(reason, bytes):
reason = reason.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) -> None:
if callback:
try:
callback(self, *args)
except Exception as e:
_logging.error(f"error from callback {callback}: {e}")
if self.on_error:
self.on_error(self, e)