#!/usr/bin/env python # # A library that provides a Python interface to the Telegram Bot API # Copyright (C) 2015-2022 # Leandro Toledo de Souza # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU Lesser Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # This program 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 Public License for more details. # # You should have received a copy of the GNU Lesser Public License # along with this program. If not, see [http://www.gnu.org/licenses/]. """This module contains the Dispatcher class.""" import logging import warnings import weakref from collections import defaultdict from functools import wraps from queue import Empty, Queue from threading import BoundedSemaphore, Event, Lock, Thread, current_thread from time import sleep from typing import ( TYPE_CHECKING, Callable, DefaultDict, Dict, List, Optional, Set, Union, Generic, TypeVar, overload, cast, ) from uuid import uuid4 from telegram import TelegramError, Update from telegram.ext import BasePersistence, ContextTypes from telegram.ext.callbackcontext import CallbackContext from telegram.ext.handler import Handler import telegram.ext.extbot from telegram.ext.callbackdatacache import CallbackDataCache from telegram.utils.deprecate import TelegramDeprecationWarning, set_new_attribute_deprecated from telegram.ext.utils.promise import Promise from telegram.utils.helpers import DefaultValue, DEFAULT_FALSE from telegram.ext.utils.types import CCT, UD, CD, BD if TYPE_CHECKING: from telegram import Bot from telegram.ext import JobQueue DEFAULT_GROUP: int = 0 UT = TypeVar('UT') def run_async( func: Callable[[Update, CallbackContext], object] ) -> Callable[[Update, CallbackContext], object]: """ Function decorator that will run the function in a new thread. Will run :attr:`telegram.ext.Dispatcher.run_async`. Using this decorator is only possible when only a single Dispatcher exist in the system. Note: DEPRECATED. Use :attr:`telegram.ext.Dispatcher.run_async` directly instead or the :attr:`Handler.run_async` parameter. Warning: If you're using ``@run_async`` you cannot rely on adding custom attributes to :class:`telegram.ext.CallbackContext`. See its docs for more info. """ @wraps(func) def async_func(*args: object, **kwargs: object) -> object: warnings.warn( 'The @run_async decorator is deprecated. Use the `run_async` parameter of ' 'your Handler or `Dispatcher.run_async` instead.', TelegramDeprecationWarning, stacklevel=2, ) return Dispatcher.get_instance()._run_async( # pylint: disable=W0212 func, *args, update=None, error_handling=False, **kwargs ) return async_func class DispatcherHandlerStop(Exception): """ Raise this in handler to prevent execution of any other handler (even in different group). In order to use this exception in a :class:`telegram.ext.ConversationHandler`, pass the optional ``state`` parameter instead of returning the next state: .. code-block:: python def callback(update, context): ... raise DispatcherHandlerStop(next_state) Attributes: state (:obj:`object`): Optional. The next state of the conversation. Args: state (:obj:`object`, optional): The next state of the conversation. """ __slots__ = ('state',) def __init__(self, state: object = None) -> None: super().__init__() self.state = state class Dispatcher(Generic[CCT, UD, CD, BD]): """This class dispatches all kinds of updates to its registered handlers. Args: bot (:class:`telegram.Bot`): The bot object that should be passed to the handlers. update_queue (:obj:`Queue`): The synchronized queue that will contain the updates. job_queue (:class:`telegram.ext.JobQueue`, optional): The :class:`telegram.ext.JobQueue` instance to pass onto handler callbacks. workers (:obj:`int`, optional): Number of maximum concurrent worker threads for the ``@run_async`` decorator and :meth:`run_async`. Defaults to 4. persistence (:class:`telegram.ext.BasePersistence`, optional): The persistence class to store data that should be persistent over restarts. use_context (:obj:`bool`, optional): If set to :obj:`True` uses the context based callback API (ignored if `dispatcher` argument is used). Defaults to :obj:`True`. **New users**: set this to :obj:`True`. context_types (:class:`telegram.ext.ContextTypes`, optional): Pass an instance of :class:`telegram.ext.ContextTypes` to customize the types used in the ``context`` interface. If not passed, the defaults documented in :class:`telegram.ext.ContextTypes` will be used. .. versionadded:: 13.6 Attributes: bot (:class:`telegram.Bot`): The bot object that should be passed to the handlers. update_queue (:obj:`Queue`): The synchronized queue that will contain the updates. job_queue (:class:`telegram.ext.JobQueue`): Optional. The :class:`telegram.ext.JobQueue` instance to pass onto handler callbacks. workers (:obj:`int`, optional): Number of maximum concurrent worker threads for the ``@run_async`` decorator and :meth:`run_async`. user_data (:obj:`defaultdict`): A dictionary handlers can use to store data for the user. chat_data (:obj:`defaultdict`): A dictionary handlers can use to store data for the chat. bot_data (:obj:`dict`): A dictionary handlers can use to store data for the bot. persistence (:class:`telegram.ext.BasePersistence`): Optional. The persistence class to store data that should be persistent over restarts. context_types (:class:`telegram.ext.ContextTypes`): Container for the types used in the ``context`` interface. .. versionadded:: 13.6 """ # Allowing '__weakref__' creation here since we need it for the singleton __slots__ = ( 'workers', 'persistence', 'use_context', 'update_queue', 'job_queue', 'user_data', 'chat_data', 'bot_data', '_update_persistence_lock', 'handlers', 'groups', 'error_handlers', 'running', '__stop_event', '__exception_event', '__async_queue', '__async_threads', 'bot', '__dict__', '__weakref__', 'context_types', ) __singleton_lock = Lock() __singleton_semaphore = BoundedSemaphore() __singleton = None logger = logging.getLogger(__name__) @overload def __init__( self: 'Dispatcher[CallbackContext[Dict, Dict, Dict], Dict, Dict, Dict]', bot: 'Bot', update_queue: Queue, workers: int = 4, exception_event: Event = None, job_queue: 'JobQueue' = None, persistence: BasePersistence = None, use_context: bool = True, ): ... @overload def __init__( self: 'Dispatcher[CCT, UD, CD, BD]', bot: 'Bot', update_queue: Queue, workers: int = 4, exception_event: Event = None, job_queue: 'JobQueue' = None, persistence: BasePersistence = None, use_context: bool = True, context_types: ContextTypes[CCT, UD, CD, BD] = None, ): ... def __init__( self, bot: 'Bot', update_queue: Queue, workers: int = 4, exception_event: Event = None, job_queue: 'JobQueue' = None, persistence: BasePersistence = None, use_context: bool = True, context_types: ContextTypes[CCT, UD, CD, BD] = None, ): self.bot = bot self.update_queue = update_queue self.job_queue = job_queue self.workers = workers self.use_context = use_context self.context_types = cast(ContextTypes[CCT, UD, CD, BD], context_types or ContextTypes()) if not use_context: warnings.warn( 'Old Handler API is deprecated - see ' 'https://github.com/python-telegram-bot/python-telegram-bot/wiki/Transition' '-guide-to-Version-12.0 for details', TelegramDeprecationWarning, stacklevel=3, ) if self.workers < 1: warnings.warn( 'Asynchronous callbacks can not be processed without at least one worker thread.' ) self.user_data: DefaultDict[int, UD] = defaultdict(self.context_types.user_data) self.chat_data: DefaultDict[int, CD] = defaultdict(self.context_types.chat_data) self.bot_data = self.context_types.bot_data() self.persistence: Optional[BasePersistence] = None self._update_persistence_lock = Lock() if persistence: if not isinstance(persistence, BasePersistence): raise TypeError("persistence must be based on telegram.ext.BasePersistence") self.persistence = persistence self.persistence.set_bot(self.bot) if self.persistence.store_user_data: self.user_data = self.persistence.get_user_data() if not isinstance(self.user_data, defaultdict): raise ValueError("user_data must be of type defaultdict") if self.persistence.store_chat_data: self.chat_data = self.persistence.get_chat_data() if not isinstance(self.chat_data, defaultdict): raise ValueError("chat_data must be of type defaultdict") if self.persistence.store_bot_data: self.bot_data = self.persistence.get_bot_data() if not isinstance(self.bot_data, self.context_types.bot_data): raise ValueError( f"bot_data must be of type {self.context_types.bot_data.__name__}" ) if self.persistence.store_callback_data: self.bot = cast(telegram.ext.extbot.ExtBot, self.bot) persistent_data = self.persistence.get_callback_data() if persistent_data is not None: if not isinstance(persistent_data, tuple) and len(persistent_data) != 2: raise ValueError('callback_data must be a 2-tuple') self.bot.callback_data_cache = CallbackDataCache( self.bot, self.bot.callback_data_cache.maxsize, persistent_data=persistent_data, ) else: self.persistence = None self.handlers: Dict[int, List[Handler]] = {} """Dict[:obj:`int`, List[:class:`telegram.ext.Handler`]]: Holds the handlers per group.""" self.groups: List[int] = [] """List[:obj:`int`]: A list with all groups.""" self.error_handlers: Dict[Callable, Union[bool, DefaultValue]] = {} """Dict[:obj:`callable`, :obj:`bool`]: A dict, where the keys are error handlers and the values indicate whether they are to be run asynchronously.""" self.running = False """:obj:`bool`: Indicates if this dispatcher is running.""" self.__stop_event = Event() self.__exception_event = exception_event or Event() self.__async_queue: Queue = Queue() self.__async_threads: Set[Thread] = set() # For backward compatibility, we allow a "singleton" mode for the dispatcher. When there's # only one instance of Dispatcher, it will be possible to use the `run_async` decorator. with self.__singleton_lock: if self.__singleton_semaphore.acquire(blocking=False): # pylint: disable=R1732 self._set_singleton(self) else: self._set_singleton(None) def __setattr__(self, key: str, value: object) -> None: # Mangled names don't automatically apply in __setattr__ (see # https://docs.python.org/3/tutorial/classes.html#private-variables), so we have to make # it mangled so they don't raise TelegramDeprecationWarning unnecessarily if key.startswith('__'): key = f"_{self.__class__.__name__}{key}" if issubclass(self.__class__, Dispatcher) and self.__class__ is not Dispatcher: object.__setattr__(self, key, value) return set_new_attribute_deprecated(self, key, value) @property def exception_event(self) -> Event: # skipcq: PY-D0003 return self.__exception_event def _init_async_threads(self, base_name: str, workers: int) -> None: base_name = f'{base_name}_' if base_name else '' for i in range(workers): thread = Thread(target=self._pooled, name=f'Bot:{self.bot.id}:worker:{base_name}{i}') self.__async_threads.add(thread) thread.start() @classmethod def _set_singleton(cls, val: Optional['Dispatcher']) -> None: cls.logger.debug('Setting singleton dispatcher as %s', val) cls.__singleton = weakref.ref(val) if val else None @classmethod def get_instance(cls) -> 'Dispatcher': """Get the singleton instance of this class. Returns: :class:`telegram.ext.Dispatcher` Raises: RuntimeError """ if cls.__singleton is not None: return cls.__singleton() # type: ignore[return-value] # pylint: disable=not-callable raise RuntimeError(f'{cls.__name__} not initialized or multiple instances exist') def _pooled(self) -> None: thr_name = current_thread().name while 1: promise = self.__async_queue.get() # If unpacking fails, the thread pool is being closed from Updater._join_async_threads if not isinstance(promise, Promise): self.logger.debug( "Closing run_async thread %s/%d", thr_name, len(self.__async_threads) ) break promise.run() if not promise.exception: self.update_persistence(update=promise.update) continue if isinstance(promise.exception, DispatcherHandlerStop): self.logger.warning( 'DispatcherHandlerStop is not supported with async functions; func: %s', promise.pooled_function.__name__, ) continue # Avoid infinite recursion of error handlers. if promise.pooled_function in self.error_handlers: self.logger.error('An uncaught error was raised while handling the error.') continue # Don't perform error handling for a `Promise` with deactivated error handling. This # should happen only via the deprecated `@run_async` decorator or `Promises` created # within error handlers if not promise.error_handling: self.logger.error('A promise with deactivated error handling raised an error.') continue # If we arrive here, an exception happened in the promise and was neither # DispatcherHandlerStop nor raised by an error handler. So we can and must handle it try: self.dispatch_error(promise.update, promise.exception, promise=promise) except Exception: self.logger.exception('An uncaught error was raised while handling the error.') def run_async( self, func: Callable[..., object], *args: object, update: object = None, **kwargs: object ) -> Promise: """ Queue a function (with given args/kwargs) to be run asynchronously. Exceptions raised by the function will be handled by the error handlers registered with :meth:`add_error_handler`. Warning: * If you're using ``@run_async``/:meth:`run_async` you cannot rely on adding custom attributes to :class:`telegram.ext.CallbackContext`. See its docs for more info. * Calling a function through :meth:`run_async` from within an error handler can lead to an infinite error handling loop. Args: func (:obj:`callable`): The function to run in the thread. *args (:obj:`tuple`, optional): Arguments to ``func``. update (:class:`telegram.Update` | :obj:`object`, optional): The update associated with the functions call. If passed, it will be available in the error handlers, in case an exception is raised by :attr:`func`. **kwargs (:obj:`dict`, optional): Keyword arguments to ``func``. Returns: Promise """ return self._run_async(func, *args, update=update, error_handling=True, **kwargs) def _run_async( self, func: Callable[..., object], *args: object, update: object = None, error_handling: bool = True, **kwargs: object, ) -> Promise: # TODO: Remove error_handling parameter once we drop the @run_async decorator promise = Promise(func, args, kwargs, update=update, error_handling=error_handling) self.__async_queue.put(promise) return promise def start(self, ready: Event = None) -> None: """Thread target of thread 'dispatcher'. Runs in background and processes the update queue. Args: ready (:obj:`threading.Event`, optional): If specified, the event will be set once the dispatcher is ready. """ if self.running: self.logger.warning('already running') if ready is not None: ready.set() return if self.__exception_event.is_set(): msg = 'reusing dispatcher after exception event is forbidden' self.logger.error(msg) raise TelegramError(msg) self._init_async_threads(str(uuid4()), self.workers) self.running = True self.logger.debug('Dispatcher started') if ready is not None: ready.set() while 1: try: # Pop update from update queue. update = self.update_queue.get(True, 1) except Empty: if self.__stop_event.is_set(): self.logger.debug('orderly stopping') break if self.__exception_event.is_set(): self.logger.critical('stopping due to exception in another thread') break continue self.logger.debug('Processing Update: %s', update) self.process_update(update) self.update_queue.task_done() self.running = False self.logger.debug('Dispatcher thread stopped') def stop(self) -> None: """Stops the thread.""" if self.running: self.__stop_event.set() while self.running: sleep(0.1) self.__stop_event.clear() # async threads must be join()ed only after the dispatcher thread was joined, # otherwise we can still have new async threads dispatched threads = list(self.__async_threads) total = len(threads) # Stop all threads in the thread pool by put()ting one non-tuple per thread for i in range(total): self.__async_queue.put(None) for i, thr in enumerate(threads): self.logger.debug('Waiting for async thread %s/%s to end', i + 1, total) thr.join() self.__async_threads.remove(thr) self.logger.debug('async thread %s/%s has ended', i + 1, total) @property def has_running_threads(self) -> bool: # skipcq: PY-D0003 return self.running or bool(self.__async_threads) def process_update(self, update: object) -> None: """Processes a single update and updates the persistence. Note: If the update is handled by least one synchronously running handlers (i.e. ``run_async=False``), :meth:`update_persistence` is called *once* after all handlers synchronous handlers are done. Each asynchronously running handler will trigger :meth:`update_persistence` on its own. Args: update (:class:`telegram.Update` | :obj:`object` | \ :class:`telegram.error.TelegramError`): The update to process. """ # An error happened while polling if isinstance(update, TelegramError): try: self.dispatch_error(None, update) except Exception: self.logger.exception('An uncaught error was raised while handling the error.') return context = None handled = False sync_modes = [] for group in self.groups: try: for handler in self.handlers[group]: check = handler.check_update(update) if check is not None and check is not False: if not context and self.use_context: context = self.context_types.context.from_update(update, self) context.refresh_data() handled = True sync_modes.append(handler.run_async) handler.handle_update(update, self, check, context) break # Stop processing with any other handler. except DispatcherHandlerStop: self.logger.debug('Stopping further handlers due to DispatcherHandlerStop') self.update_persistence(update=update) break # Dispatch any error. except Exception as exc: try: self.dispatch_error(update, exc) except DispatcherHandlerStop: self.logger.debug('Error handler stopped further handlers') break # Errors should not stop the thread. except Exception: self.logger.exception('An uncaught error was raised while handling the error.') # Update persistence, if handled handled_only_async = all(sync_modes) if handled: # Respect default settings if all(mode is DEFAULT_FALSE for mode in sync_modes) and self.bot.defaults: handled_only_async = self.bot.defaults.run_async # If update was only handled by async handlers, we don't need to update here if not handled_only_async: self.update_persistence(update=update) def add_handler(self, handler: Handler[UT, CCT], group: int = DEFAULT_GROUP) -> None: """Register a handler. TL;DR: Order and priority counts. 0 or 1 handlers per group will be used. End handling of update with :class:`telegram.ext.DispatcherHandlerStop`. A handler must be an instance of a subclass of :class:`telegram.ext.Handler`. All handlers are organized in groups with a numeric value. The default group is 0. All groups will be evaluated for handling an update, but only 0 or 1 handler per group will be used. If :class:`telegram.ext.DispatcherHandlerStop` is raised from one of the handlers, no further handlers (regardless of the group) will be called. The priority/order of handlers is determined as follows: * Priority of the group (lower group number == higher priority) * The first handler in a group which should handle an update (see :attr:`telegram.ext.Handler.check_update`) will be used. Other handlers from the group will not be used. The order in which handlers were added to the group defines the priority. Args: handler (:class:`telegram.ext.Handler`): A Handler instance. group (:obj:`int`, optional): The group identifier. Default is 0. """ # Unfortunately due to circular imports this has to be here from .conversationhandler import ConversationHandler # pylint: disable=C0415 if not isinstance(handler, Handler): raise TypeError(f'handler is not an instance of {Handler.__name__}') if not isinstance(group, int): raise TypeError('group is not int') # For some reason MyPy infers the type of handler is here, # so for now we just ignore all the errors if ( isinstance(handler, ConversationHandler) and handler.persistent # type: ignore[attr-defined] and handler.name # type: ignore[attr-defined] ): if not self.persistence: raise ValueError( f"ConversationHandler {handler.name} " # type: ignore[attr-defined] f"can not be persistent if dispatcher has no persistence" ) handler.persistence = self.persistence # type: ignore[attr-defined] handler.conversations = ( # type: ignore[attr-defined] self.persistence.get_conversations(handler.name) # type: ignore[attr-defined] ) if group not in self.handlers: self.handlers[group] = [] self.groups.append(group) self.groups = sorted(self.groups) self.handlers[group].append(handler) def remove_handler(self, handler: Handler, group: int = DEFAULT_GROUP) -> None: """Remove a handler from the specified group. Args: handler (:class:`telegram.ext.Handler`): A Handler instance. group (:obj:`object`, optional): The group identifier. Default is 0. """ if handler in self.handlers[group]: self.handlers[group].remove(handler) if not self.handlers[group]: del self.handlers[group] self.groups.remove(group) def update_persistence(self, update: object = None) -> None: """Update :attr:`user_data`, :attr:`chat_data` and :attr:`bot_data` in :attr:`persistence`. Args: update (:class:`telegram.Update`, optional): The update to process. If passed, only the corresponding ``user_data`` and ``chat_data`` will be updated. """ with self._update_persistence_lock: self.__update_persistence(update) def __update_persistence(self, update: object = None) -> None: if self.persistence: # We use list() here in order to decouple chat_ids from self.chat_data, as dict view # objects will change, when the dict does and we want to loop over chat_ids chat_ids = list(self.chat_data.keys()) user_ids = list(self.user_data.keys()) if isinstance(update, Update): if update.effective_chat: chat_ids = [update.effective_chat.id] else: chat_ids = [] if update.effective_user: user_ids = [update.effective_user.id] else: user_ids = [] if self.persistence.store_callback_data: self.bot = cast(telegram.ext.extbot.ExtBot, self.bot) try: self.persistence.update_callback_data( self.bot.callback_data_cache.persistence_data ) except Exception as exc: try: self.dispatch_error(update, exc) except Exception: message = ( 'Saving callback data raised an error and an ' 'uncaught error was raised while handling ' 'the error with an error_handler' ) self.logger.exception(message) if self.persistence.store_bot_data: try: self.persistence.update_bot_data(self.bot_data) except Exception as exc: try: self.dispatch_error(update, exc) except Exception: message = ( 'Saving bot data raised an error and an ' 'uncaught error was raised while handling ' 'the error with an error_handler' ) self.logger.exception(message) if self.persistence.store_chat_data: for chat_id in chat_ids: try: self.persistence.update_chat_data(chat_id, self.chat_data[chat_id]) except Exception as exc: try: self.dispatch_error(update, exc) except Exception: message = ( 'Saving chat data raised an error and an ' 'uncaught error was raised while handling ' 'the error with an error_handler' ) self.logger.exception(message) if self.persistence.store_user_data: for user_id in user_ids: try: self.persistence.update_user_data(user_id, self.user_data[user_id]) except Exception as exc: try: self.dispatch_error(update, exc) except Exception: message = ( 'Saving user data raised an error and an ' 'uncaught error was raised while handling ' 'the error with an error_handler' ) self.logger.exception(message) def add_error_handler( self, callback: Callable[[object, CCT], None], run_async: Union[bool, DefaultValue] = DEFAULT_FALSE, # pylint: disable=W0621 ) -> None: """Registers an error handler in the Dispatcher. This handler will receive every error which happens in your bot. Note: Attempts to add the same callback multiple times will be ignored. Warning: The errors handled within these handlers won't show up in the logger, so you need to make sure that you reraise the error. Args: callback (:obj:`callable`): The callback function for this error handler. Will be called when an error is raised. Callback signature for context based API: ``def callback(update: object, context: CallbackContext)`` The error that happened will be present in context.error. run_async (:obj:`bool`, optional): Whether this handlers callback should be run asynchronously using :meth:`run_async`. Defaults to :obj:`False`. Note: See https://github.com/python-telegram-bot/python-telegram-bot/wiki\ /Transition-guide-to-Version-12.0 for more info about switching to context based API. """ if callback in self.error_handlers: self.logger.debug('The callback is already registered as an error handler. Ignoring.') return if run_async is DEFAULT_FALSE and self.bot.defaults and self.bot.defaults.run_async: run_async = True self.error_handlers[callback] = run_async def remove_error_handler(self, callback: Callable[[object, CCT], None]) -> None: """Removes an error handler. Args: callback (:obj:`callable`): The error handler to remove. """ self.error_handlers.pop(callback, None) def dispatch_error( self, update: Optional[object], error: Exception, promise: Promise = None ) -> None: """Dispatches an error. Args: update (:obj:`object` | :class:`telegram.Update`): The update that caused the error. error (:obj:`Exception`): The error that was raised. promise (:class:`telegram.utils.Promise`, optional): The promise whose pooled function raised the error. """ async_args = None if not promise else promise.args async_kwargs = None if not promise else promise.kwargs if self.error_handlers: for callback, run_async in self.error_handlers.items(): # pylint: disable=W0621 if self.use_context: context = self.context_types.context.from_error( update, error, self, async_args=async_args, async_kwargs=async_kwargs ) if run_async: self.run_async(callback, update, context, update=update) else: callback(update, context) else: if run_async: self.run_async(callback, self.bot, update, error, update=update) else: callback(self.bot, update, error) else: self.logger.exception( 'No error handlers are registered, logging exception.', exc_info=error )