import inspect 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 from ._dispatcher import Dispatcher, DispatcherBase, SSLDispatcher, WrappedDispatcher """ _app.py websocket - WebSocket client library for Python Copyright 2025 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 set_reconnect(reconnectInterval: int) -> None: global RECONNECT RECONNECT = reconnectInterval class WebSocketApp: """ Higher level of APIs are provided. The interface is like JavaScript WebSocket object. """ def __init__( self, url: str, header: Optional[ Union[ list[str], dict[str, str], Callable[[], Union[list[str], dict[str, str]]], ] ] = None, on_open: Optional[Callable[["WebSocketApp"], None]] = None, on_reconnect: Optional[Callable[["WebSocketApp"], None]] = None, on_message: Optional[Callable[["WebSocketApp", Any], None]] = None, on_error: Optional[Callable[["WebSocketApp", Any], None]] = None, on_close: Optional[Callable[["WebSocketApp", 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[str]] = 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: Optional[Union[float, int]] = 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) # Handle thread leak - if thread doesn't terminate within timeout, # force cleanup and log warning instead of abandoning the thread if self.ping_thread.is_alive(): _logging.warning( "Ping thread failed to terminate within 3 seconds, " "forcing cleanup. Thread may be blocked." ) # Force cleanup by clearing references even if thread is still alive # The daemon thread will eventually be cleaned up by Python's GC # but we prevent resource leaks by not holding references # Always clean up references regardless of thread state self.ping_thread = None self.stop_ping = None self.last_ping_tm = self.last_pong_tm = float(0) def _send_ping(self) -> None: if self.stop_ping is None: return 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 ready(self): return self.sock and self.sock.connected def run_forever( self, sockopt: tuple = None, sslopt: dict = None, ping_interval: Union[float, int] = 0, ping_timeout: Optional[Union[float, int]] = 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: # in cases like handleDisconnect, the "on_error" callback is called first. If the WebSocketApp # is being used in a multithreaded application, we nee to make sure that "self.sock" is cleared # before calling close, otherwise logic built around the sock being set can cause issues - # specifically calling "run_forever" again, since is checks if "self.sock" is set. current_sock = self.sock self.sock = None current_sock.close() close_status_code, close_reason = self._get_close_args( close_frame if close_frame else None ) # Finally call the callback AFTER all teardown is complete self._callback(self.on_close, close_status_code, close_reason) def initialize_socket(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, dispatcher=dispatcher, ) 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: teardown() return False if self.sock is None: return False try: op_code, frame = self.sock.recv_data_frame(True) except ( WebSocketConnectionClosedException, KeyboardInterrupt, SSLEOFError, ) as e: if custom_dispatcher: return closed(e) else: raise e if op_code == ABNF.OPCODE_CLOSE: return closed(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 closed( e: Union[ WebSocketConnectionClosedException, ConnectionRefusedError, KeyboardInterrupt, SystemExit, Exception, str, ] = "closed unexpectedly", ) -> bool: if type(e) is str: e = WebSocketConnectionClosedException(e) return handleDisconnect(e, bool(reconnect)) # type: ignore[arg-type] 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, initialize_socket) else: _logging.error(f"{e} - goodbye") teardown() return self.has_errored custom_dispatcher = bool(dispatcher) dispatcher = self.create_dispatcher( ping_timeout, dispatcher, parse_url(self.url)[3], closed ) try: initialize_socket() 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, initialize_socket) 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: Optional[Union[float, int]], dispatcher: Optional[DispatcherBase] = None, is_ssl: bool = False, handleDisconnect: Callable = None, ) -> Union[Dispatcher, SSLDispatcher, WrappedDispatcher]: if dispatcher: # If custom dispatcher is set, use WrappedDispatcher return WrappedDispatcher(self, ping_timeout, dispatcher, handleDisconnect) 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}") # Bug fix: Prevent infinite recursion by not calling on_error # when the failing callback IS on_error itself if self.on_error and callback is not self.on_error: self.on_error(self, e)