python-telegram-bot/telegram/ext/dispatcher.py

664 lines
27 KiB
Python

#!/usr/bin/env python
#
# A library that provides a Python interface to the Telegram Bot API
# Copyright (C) 2015-2020
# Leandro Toledo de Souza <devs@python-telegram-bot.org>
#
# 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, Any, Callable, DefaultDict, Dict, List, Optional, Set, Union
from uuid import uuid4
from telegram import TelegramError, Update
from telegram.ext import BasePersistence
from telegram.ext.callbackcontext import CallbackContext
from telegram.ext.handler import Handler
from telegram.utils.deprecate import TelegramDeprecationWarning
from telegram.utils.promise import Promise
from telegram.utils.types import HandlerArg
if TYPE_CHECKING:
from telegram import Bot
from telegram.ext import JobQueue
DEFAULT_GROUP: int = 0
def run_async(
func: Callable[[Update, CallbackContext], Any]
) -> Callable[[Update, CallbackContext], Any]:
"""
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: Any, **kwargs: Any) -> Any:
warnings.warn(
'The @run_async decorator is deprecated. Use the `run_async` parameter of'
'`Dispatcher.add_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 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.
"""
def __init__(self, state: object = None) -> None:
super().__init__()
self.state = state
class Dispatcher:
"""This class dispatches all kinds of updates to its registered handlers.
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.
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`.
"""
__singleton_lock = Lock()
__singleton_semaphore = BoundedSemaphore()
__singleton = None
logger = logging.getLogger(__name__)
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,
):
self.bot = bot
self.update_queue = update_queue
self.job_queue = job_queue
self.workers = workers
self.use_context = use_context
if not use_context:
warnings.warn(
'Old Handler API is deprecated - see https://git.io/fxJuV for details',
TelegramDeprecationWarning,
stacklevel=3,
)
self.user_data: DefaultDict[int, Dict[Any, Any]] = defaultdict(dict)
self.chat_data: DefaultDict[int, Dict[Any, Any]] = defaultdict(dict)
self.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, dict):
raise ValueError("bot_data must be of type dict")
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, bool] = {}
"""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):
self._set_singleton(self)
else:
self._set_singleton(None)
@property
def exception_event(self) -> Event:
return self.__exception_event
def _init_async_threads(self, base_name: str, workers: int) -> None:
base_name = '{}_'.format(base_name) if base_name else ''
for i in range(workers):
thread = Thread(
target=self._pooled, name='Bot:{}:worker:{}{}'.format(self.bot.id, 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('{} not initialized or multiple instances exist'.format(cls.__name__))
def _pooled(self) -> None:
thr_name = current_thread().getName()
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[..., Any], *args: Any, update: HandlerArg = None, **kwargs: Any
) -> 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`, 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[..., Any],
*args: Any,
update: HandlerArg = None,
error_handling: bool = True,
**kwargs: Any,
) -> 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:
return self.running or bool(self.__async_threads)
def process_update(self, update: Union[str, Update, TelegramError]) -> None:
"""Processes a single update.
Args:
update (:obj:`str` | :class:`telegram.Update` | :class:`telegram.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
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 = CallbackContext.from_update(update, self)
handler.handle_update(update, self, check, context)
# If handler runs async updating immediately doesn't make sense
if not handler.run_async:
self.update_persistence(update=update)
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.')
def add_handler(self, handler: Handler, 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('handler is not an instance of {}'.format(Handler.__name__))
if not isinstance(group, int):
raise TypeError('group is not int')
if isinstance(handler, ConversationHandler) and handler.persistent and handler.name:
if not self.persistence:
raise ValueError(
"ConversationHandler {} can not be persistent if dispatcher has no "
"persistence".format(handler.name)
)
handler.persistence = self.persistence
handler.conversations = self.persistence.get_conversations(handler.name)
if group not in self.handlers:
self.handlers[group] = list()
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: HandlerArg = 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: HandlerArg = 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_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[[Any, CallbackContext], None],
run_async: bool = 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: Update, 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://git.io/fxJuV 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
self.error_handlers[callback] = run_async
def remove_error_handler(self, callback: Callable[[Any, CallbackContext], 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[HandlerArg], error: Exception, promise: Promise = None
) -> None:
"""Dispatches an error.
Args:
update (:obj:`str` | :class:`telegram.Update` | None): 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 = CallbackContext.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
)