Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/engineio/async_server.py

@@ -0,0 +1,578 @@
+import asyncio
+import urllib
+
+from . import base_server
+from . import exceptions
+from . import packet
+from . import async_socket
+
+# this set is used to keep references to background tasks to prevent them from
+# being garbage collected mid-execution. Solution taken from
+# https://docs.python.org/3/library/asyncio-task.html#asyncio.create_task
+task_reference_holder = set()
+
+
+class AsyncServer(base_server.BaseServer):
+    """An Engine.IO server for asyncio.
+
+    This class implements a fully compliant Engine.IO web server with support
+    for websocket and long-polling transports, compatible with the asyncio
+    framework on Python 3.5 or newer.
+
+    :param async_mode: The asynchronous model to use. See the Deployment
+                       section in the documentation for a description of the
+                       available options. Valid async modes are "aiohttp",
+                       "sanic", "tornado" and "asgi". If this argument is not
+                       given, "aiohttp" is tried first, followed by "sanic",
+                       "tornado", and finally "asgi". The first async mode that
+                       has all its dependencies installed is the one that is
+                       chosen.
+    :param ping_interval: The interval in seconds at which the server pings
+                          the client. The default is 25 seconds. For advanced
+                          control, a two element tuple can be given, where
+                          the first number is the ping interval and the second
+                          is a grace period added by the server.
+    :param ping_timeout: The time in seconds that the client waits for the
+                         server to respond before disconnecting. The default
+                         is 20 seconds.
+    :param max_http_buffer_size: The maximum size that is accepted for incoming
+                                 messages.  The default is 1,000,000 bytes. In
+                                 spite of its name, the value set in this
+                                 argument is enforced for HTTP long-polling and
+                                 WebSocket connections.
+    :param allow_upgrades: Whether to allow transport upgrades or not.
+    :param http_compression: Whether to compress packages when using the
+                             polling transport.
+    :param compression_threshold: Only compress messages when their byte size
+                                  is greater than this value.
+    :param cookie: If set to a string, it is the name of the HTTP cookie the
+                   server sends back tot he client containing the client
+                   session id. If set to a dictionary, the ``'name'`` key
+                   contains the cookie name and other keys define cookie
+                   attributes, where the value of each attribute can be a
+                   string, a callable with no arguments, or a boolean. If set
+                   to ``None`` (the default), a cookie is not sent to the
+                   client.
+    :param cors_allowed_origins: Origin or list of origins that are allowed to
+                                 connect to this server. Only the same origin
+                                 is allowed by default. Set this argument to
+                                 ``'*'`` to allow all origins, or to ``[]`` to
+                                 disable CORS handling.
+    :param cors_credentials: Whether credentials (cookies, authentication) are
+                             allowed in requests to this server.
+    :param logger: To enable logging set to ``True`` or pass a logger object to
+                   use. To disable logging set to ``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 async_handlers: If set to ``True``, run message event handlers in
+                           non-blocking threads. To run handlers synchronously,
+                           set to ``False``. The default is ``True``.
+    :param monitor_clients: If set to ``True``, a background task will ensure
+                            inactive clients are closed. Set to ``False`` to
+                            disable the monitoring task (not recommended). The
+                            default is ``True``.
+    :param transports: The list of allowed transports. Valid transports
+                       are ``'polling'`` and ``'websocket'``. Defaults to
+                       ``['polling', 'websocket']``.
+    :param kwargs: Reserved for future extensions, any additional parameters
+                   given as keyword arguments will be silently ignored.
+    """
+    def is_asyncio_based(self):
+        return True
+
+    def async_modes(self):
+        return ['aiohttp', 'sanic', 'tornado', 'asgi']
+
+    def attach(self, app, engineio_path='engine.io'):
+        """Attach the Engine.IO server to an application."""
+        engineio_path = engineio_path.strip('/')
+        self._async['create_route'](app, self, '/{}/'.format(engineio_path))
+
+    async def send(self, sid, data):
+        """Send a message to a client.
+
+        :param sid: The session id of the recipient 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(sid, packet.Packet(packet.MESSAGE, data=data))
+
+    async def send_packet(self, sid, pkt):
+        """Send a raw packet to a client.
+
+        :param sid: The session id of the recipient client.
+        :param pkt: The packet to send to the client.
+
+        Note: this method is a coroutine.
+        """
+        try:
+            socket = self._get_socket(sid)
+        except KeyError:
+            # the socket is not available
+            self.logger.warning('Cannot send to sid %s', sid)
+            return
+        await socket.send(pkt)
+
+    async def get_session(self, sid):
+        """Return the user session for a client.
+
+        :param sid: The session id of the client.
+
+        The return value is a dictionary. Modifications made to this
+        dictionary are not guaranteed to be preserved. If you want to modify
+        the user session, use the ``session`` context manager instead.
+        """
+        socket = self._get_socket(sid)
+        return socket.session
+
+    async def save_session(self, sid, session):
+        """Store the user session for a client.
+
+        :param sid: The session id of the client.
+        :param session: The session dictionary.
+        """
+        socket = self._get_socket(sid)
+        socket.session = session
+
+    def session(self, sid):
+        """Return the user session for a client with context manager syntax.
+
+        :param sid: The session id of the client.
+
+        This is a context manager that returns the user session dictionary for
+        the client. Any changes that are made to this dictionary inside the
+        context manager block are saved back to the session. Example usage::
+
+            @eio.on('connect')
+            def on_connect(sid, environ):
+                username = authenticate_user(environ)
+                if not username:
+                    return False
+                with eio.session(sid) as session:
+                    session['username'] = username
+
+            @eio.on('message')
+            def on_message(sid, msg):
+                async with eio.session(sid) as session:
+                    print('received message from ', session['username'])
+        """
+        class _session_context_manager(object):
+            def __init__(self, server, sid):
+                self.server = server
+                self.sid = sid
+                self.session = None
+
+            async def __aenter__(self):
+                self.session = await self.server.get_session(sid)
+                return self.session
+
+            async def __aexit__(self, *args):
+                await self.server.save_session(sid, self.session)
+
+        return _session_context_manager(self, sid)
+
+    async def disconnect(self, sid=None):
+        """Disconnect a client.
+
+        :param sid: The session id of the client to close. If this parameter
+                    is not given, then all clients are closed.
+
+        Note: this method is a coroutine.
+        """
+        if sid is not None:
+            try:
+                socket = self._get_socket(sid)
+            except KeyError:  # pragma: no cover
+                # the socket was already closed or gone
+                pass
+            else:
+                await socket.close()
+                if sid in self.sockets:  # pragma: no cover
+                    del self.sockets[sid]
+        else:
+            await asyncio.wait([asyncio.create_task(client.close())
+                                for client in self.sockets.values()])
+            self.sockets = {}
+
+    async def handle_request(self, *args, **kwargs):
+        """Handle an HTTP request from the client.
+
+        This is the entry point of the Engine.IO application. This function
+        returns the HTTP response to deliver to the client.
+
+        Note: this method is a coroutine.
+        """
+        translate_request = self._async['translate_request']
+        if asyncio.iscoroutinefunction(translate_request):
+            environ = await translate_request(*args, **kwargs)
+        else:
+            environ = translate_request(*args, **kwargs)
+
+        if self.cors_allowed_origins != []:
+            # Validate the origin header if present
+            # This is important for WebSocket more than for HTTP, since
+            # browsers only apply CORS controls to HTTP.
+            origin = environ.get('HTTP_ORIGIN')
+            if origin:
+                allowed_origins = self._cors_allowed_origins(environ)
+                if allowed_origins is not None and origin not in \
+                        allowed_origins:
+                    self._log_error_once(
+                        origin + ' is not an accepted origin.', 'bad-origin')
+                    return await self._make_response(
+                        self._bad_request(
+                            origin + ' is not an accepted origin.'),
+                        environ)
+
+        method = environ['REQUEST_METHOD']
+        query = urllib.parse.parse_qs(environ.get('QUERY_STRING', ''))
+
+        sid = query['sid'][0] if 'sid' in query else None
+        jsonp = False
+        jsonp_index = None
+
+        # make sure the client uses an allowed transport
+        transport = query.get('transport', ['polling'])[0]
+        if transport not in self.transports:
+            self._log_error_once('Invalid transport', 'bad-transport')
+            return await self._make_response(
+                self._bad_request('Invalid transport'), environ)
+
+        # make sure the client speaks a compatible Engine.IO version
+        sid = query['sid'][0] if 'sid' in query else None
+        if sid is None and query.get('EIO') != ['4']:
+            self._log_error_once(
+                'The client is using an unsupported version of the Socket.IO '
+                'or Engine.IO protocols', 'bad-version'
+            )
+            return await self._make_response(self._bad_request(
+                'The client is using an unsupported version of the Socket.IO '
+                'or Engine.IO protocols'
+            ), environ)
+
+        if 'j' in query:
+            jsonp = True
+            try:
+                jsonp_index = int(query['j'][0])
+            except (ValueError, KeyError, IndexError):
+                # Invalid JSONP index number
+                pass
+
+        if jsonp and jsonp_index is None:
+            self._log_error_once('Invalid JSONP index number',
+                                 'bad-jsonp-index')
+            r = self._bad_request('Invalid JSONP index number')
+        elif method == 'GET':
+            upgrade_header = environ.get('HTTP_UPGRADE').lower() \
+                if 'HTTP_UPGRADE' in environ else None
+            if sid is None:
+                # transport must be one of 'polling' or 'websocket'.
+                # if 'websocket', the HTTP_UPGRADE header must match.
+                if transport == 'polling' \
+                        or transport == upgrade_header == 'websocket':
+                    r = await self._handle_connect(environ, transport,
+                                                   jsonp_index)
+                else:
+                    self._log_error_once('Invalid websocket upgrade',
+                                         'bad-upgrade')
+                    r = self._bad_request('Invalid websocket upgrade')
+            else:
+                if sid not in self.sockets:
+                    self._log_error_once('Invalid session ' + sid, 'bad-sid')
+                    r = self._bad_request('Invalid session ' + sid)
+                else:
+                    socket = self._get_socket(sid)
+                    if self.transport(sid) != transport and \
+                            transport != upgrade_header:
+                        self._log_error_once(
+                            'Invalid transport for session ' + sid,
+                            'bad-transport')
+                        r = self._bad_request('Invalid transport')
+                    else:
+                        try:
+                            packets = await socket.handle_get_request(environ)
+                            if isinstance(packets, list):
+                                r = self._ok(packets, jsonp_index=jsonp_index)
+                            else:
+                                r = packets
+                        except exceptions.EngineIOError:
+                            if sid in self.sockets:  # pragma: no cover
+                                await self.disconnect(sid)
+                            r = self._bad_request()
+                        if sid in self.sockets and self.sockets[sid].closed:
+                            del self.sockets[sid]
+        elif method == 'POST':
+            if sid is None or sid not in self.sockets:
+                self._log_error_once('Invalid session ' + sid, 'bad-sid')
+                r = self._bad_request('Invalid session ' + sid)
+            else:
+                socket = self._get_socket(sid)
+                try:
+                    await socket.handle_post_request(environ)
+                    r = self._ok(jsonp_index=jsonp_index)
+                except exceptions.EngineIOError:
+                    if sid in self.sockets:  # pragma: no cover
+                        await self.disconnect(sid)
+                    r = self._bad_request()
+                except:  # pragma: no cover
+                    # for any other unexpected errors, we log the error
+                    # and keep going
+                    self.logger.exception('post request handler error')
+                    r = self._ok(jsonp_index=jsonp_index)
+        elif method == 'OPTIONS':
+            r = self._ok()
+        else:
+            self.logger.warning('Method %s not supported', method)
+            r = self._method_not_found()
+        if not isinstance(r, dict):
+            return r
+        if self.http_compression and \
+                len(r['response']) >= self.compression_threshold:
+            encodings = [e.split(';')[0].strip() for e in
+                         environ.get('HTTP_ACCEPT_ENCODING', '').split(',')]
+            for encoding in encodings:
+                if encoding in self.compression_methods:
+                    r['response'] = \
+                        getattr(self, '_' + encoding)(r['response'])
+                    r['headers'] += [('Content-Encoding', encoding)]
+                    break
+        return await self._make_response(r, environ)
+
+    async def shutdown(self):
+        """Stop Socket.IO background tasks.
+
+        This method stops background activity initiated by the Socket.IO
+        server. It must be called before shutting down the web server.
+        """
+        self.logger.info('Socket.IO is shutting down')
+        if self.service_task_event:  # pragma: no cover
+            self.service_task_event.set()
+            await self.service_task_handle
+            self.service_task_handle = None
+
+    def start_background_task(self, target, *args, **kwargs):
+        """Start a background task using the appropriate async model.
+
+        This is a utility function that applications can use to start a
+        background task using the method that is compatible with the
+        selected async mode.
+
+        :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 using the appropriate async
+        model.
+
+        This is a utility function that applications can use to put a task to
+        sleep without having to worry about using the correct call for the
+        selected async mode.
+
+        Note: this method is a coroutine.
+        """
+        return await asyncio.sleep(seconds)
+
+    def create_queue(self, *args, **kwargs):
+        """Create a queue object using the appropriate async model.
+
+        This is a utility function that applications can use to create a queue
+        without having to worry about using the correct call for the selected
+        async mode. For asyncio based async modes, this returns an instance of
+        ``asyncio.Queue``.
+        """
+        return asyncio.Queue(*args, **kwargs)
+
+    def get_queue_empty_exception(self):
+        """Return the queue empty exception for the appropriate async model.
+
+        This is a utility function that applications can use to work with a
+        queue without having to worry about using the correct call for the
+        selected async mode. For asyncio based async modes, this returns an
+        instance of ``asyncio.QueueEmpty``.
+        """
+        return asyncio.QueueEmpty
+
+    def create_event(self, *args, **kwargs):
+        """Create an event object using the appropriate async model.
+
+        This is a utility function that applications can use to create an
+        event without having to worry about using the correct call for the
+        selected async mode. For asyncio based async modes, this returns
+        an instance of ``asyncio.Event``.
+        """
+        return asyncio.Event(*args, **kwargs)
+
+    async def _make_response(self, response_dict, environ):
+        cors_headers = self._cors_headers(environ)
+        make_response = self._async['make_response']
+        if asyncio.iscoroutinefunction(make_response):
+            response = await make_response(
+                response_dict['status'],
+                response_dict['headers'] + cors_headers,
+                response_dict['response'], environ)
+        else:
+            response = make_response(
+                response_dict['status'],
+                response_dict['headers'] + cors_headers,
+                response_dict['response'], environ)
+        return response
+
+    async def _handle_connect(self, environ, transport, jsonp_index=None):
+        """Handle a client connection request."""
+        if self.start_service_task:
+            # start the service task to monitor connected clients
+            self.start_service_task = False
+            self.service_task_handle = self.start_background_task(
+                self._service_task)
+
+        sid = self.generate_id()
+        s = async_socket.AsyncSocket(self, sid)
+        self.sockets[sid] = s
+
+        pkt = packet.Packet(
+            packet.OPEN, {'sid': sid,
+                          'upgrades': self._upgrades(sid, transport),
+                          'pingTimeout': int(self.ping_timeout * 1000),
+                          'pingInterval': int(self.ping_interval * 1000)})
+        await s.send(pkt)
+        s.schedule_ping()
+
+        ret = await self._trigger_event('connect', sid, environ,
+                                        run_async=False)
+        if ret is not None and ret is not True:
+            del self.sockets[sid]
+            self.logger.warning('Application rejected connection')
+            return self._unauthorized(ret or None)
+
+        if transport == 'websocket':
+            ret = await s.handle_get_request(environ)
+            if s.closed and sid in self.sockets:
+                # websocket connection ended, so we are done
+                del self.sockets[sid]
+            return ret
+        else:
+            s.connected = True
+            headers = None
+            if self.cookie:
+                if isinstance(self.cookie, dict):
+                    headers = [(
+                        'Set-Cookie',
+                        self._generate_sid_cookie(sid, self.cookie)
+                    )]
+                else:
+                    headers = [(
+                        'Set-Cookie',
+                        self._generate_sid_cookie(sid, {
+                            'name': self.cookie, 'path': '/', 'SameSite': 'Lax'
+                        })
+                    )]
+            try:
+                return self._ok(await s.poll(), headers=headers,
+                                jsonp_index=jsonp_index)
+            except exceptions.QueueEmpty:
+                return self._bad_request()
+
+    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]):
+                async def run_async_handler():
+                    try:
+                        return 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
+
+                if run_async:
+                    ret = self.start_background_task(run_async_handler)
+                    task_reference_holder.add(ret)
+                    ret.add_done_callback(task_reference_holder.discard)
+                else:
+                    ret = await run_async_handler()
+            else:
+                async def run_sync_handler():
+                    try:
+                        return 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
+
+                if run_async:
+                    ret = self.start_background_task(run_sync_handler)
+                    task_reference_holder.add(ret)
+                    ret.add_done_callback(task_reference_holder.discard)
+                else:
+                    ret = await run_sync_handler()
+        return ret
+
+    async def _service_task(self):  # pragma: no cover
+        """Monitor connected clients and clean up those that time out."""
+        self.service_task_event = self.create_event()
+        while not self.service_task_event.is_set():
+            if len(self.sockets) == 0:
+                # nothing to do
+                try:
+                    await asyncio.wait_for(self.service_task_event.wait(),
+                                           timeout=self.ping_timeout)
+                    break
+                except asyncio.TimeoutError:
+                    continue
+
+            # go through the entire client list in a ping interval cycle
+            sleep_interval = self.ping_timeout / len(self.sockets)
+
+            try:
+                # iterate over the current clients
+                for s in self.sockets.copy().values():
+                    if s.closed:
+                        try:
+                            del self.sockets[s.sid]
+                        except KeyError:
+                            # the socket could have also been removed by
+                            # the _get_socket() method from another thread
+                            pass
+                    elif not s.closing:
+                        await s.check_ping_timeout()
+                    try:
+                        await asyncio.wait_for(self.service_task_event.wait(),
+                                               timeout=sleep_interval)
+                        raise KeyboardInterrupt()
+                    except asyncio.TimeoutError:
+                        continue
+            except (
+                SystemExit,
+                KeyboardInterrupt,
+                asyncio.CancelledError,
+                GeneratorExit,
+            ):
+                self.logger.info('service task canceled')
+                break
+            except:
+                if asyncio.get_event_loop().is_closed():
+                    self.logger.info('event loop is closed, exiting service '
+                                     'task')
+                    break
+
+                # an unexpected exception has occurred, log it and continue
+                self.logger.exception('service task exception')