python-telegram-bot/telegram/ext/jobqueue.py
2016-05-26 13:55:56 +02:00

230 lines
6.9 KiB
Python

#!/usr/bin/env python
#
# A library that provides a Python interface to the Telegram Bot API
# Copyright (C) 2015-2016
# 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 class JobQueue."""
import logging
import time
from threading import Thread, Lock, Event
from queue import PriorityQueue
class JobQueue(object):
"""
This class allows you to periodically perform tasks with the bot.
Attributes:
queue (PriorityQueue):
bot (Bot):
Args:
bot (Bot): The bot instance that should be passed to the jobs
"""
def __init__(self, bot):
self.queue = PriorityQueue()
self.bot = bot
self.logger = logging.getLogger(__name__)
self.__lock = Lock()
self.__tick = Event()
self.next_peek = None
self.running = False
def put(self, job, next_t=None, prevent_autostart=False):
"""
Queue a new job. If the JobQueue is not running, it will be started.
Args:
job (Job): The ``Job`` instance representing the new job
next_t (Optional[float]): Time in seconds in which the job should be executed first.
Defaults to ``job.interval``
prevent_autostart (Optional[bool]): If ``True``, the job queue will not be started
automatically if it is not running. Defaults to ``False``
"""
job.job_queue = self
if next_t is None:
next_t = job.interval
now = time.time()
next_t += now
self.logger.debug('Putting a %s with t=%f' % (job.name, next_t))
self.queue.put((next_t, job))
if not self.next_peek or self.next_peek > next_t:
self.next_peek = next_t
self.__tick.set()
if not self.running and not prevent_autostart:
self.logger.debug('Auto-starting JobQueue')
self.start()
def tick(self):
"""
Run all jobs that are due and re-enqueue them with their interval
"""
now = time.time()
self.logger.debug('Ticking jobs with t=%f' % now)
while not self.queue.empty():
t, job = self.queue.queue[0]
self.logger.debug('Peeked at %s with t=%f' % (job.name, t))
if t <= now:
self.queue.get()
if job._remove.is_set():
self.logger.debug('Removing job %s' % job.name)
continue
elif job.enabled:
self.logger.debug('Running job %s' % job.name)
try:
job.run()
except:
self.logger.exception(
'An uncaught error was raised while executing job %s' % job.name)
else:
self.logger.debug('Skipping disabled job %s' % job.name)
if job.repeat:
self.put(job)
continue
self.logger.debug('Next task isn\'t due yet. Finished!')
self.next_peek = t
break
else:
self.next_peek = None
self.__tick.clear()
def start(self):
"""
Starts the job_queue thread.
"""
self.__lock.acquire()
if not self.running:
self.running = True
self.__lock.release()
job_queue_thread = Thread(target=self._start, name="job_queue")
job_queue_thread.start()
self.logger.debug('Job Queue thread started')
else:
self.__lock.release()
def _start(self):
"""
Thread target of thread 'job_queue'. Runs in background and performs
ticks on the job queue.
"""
while self.running:
self.__tick.wait(self.next_peek and self.next_peek - time.time())
# If we were woken up by set(), wait with the new timeout
if self.__tick.is_set():
self.__tick.clear()
continue
self.tick()
self.logger.debug('Job Queue thread stopped')
def stop(self):
"""
Stops the thread
"""
with self.__lock:
self.running = False
self.__tick.set()
def jobs(self):
"""Returns a tuple of all jobs that are currently in the ``JobQueue``"""
return tuple(job[1] for job in self.queue.queue if job)
class Job(object):
"""This class encapsulates a Job
Attributes:
callback (function):
interval (float):
repeat (bool):
name (str):
enabled (bool): If this job is currently active
Args:
callback (function): The callback function that should be executed by the Job. It should
take two parameters ``bot`` and ``job``, where ``job`` is the ``Job`` instance. It
can be used to terminate the job or modify its interval.
interval (float): The interval in which this job should execute its callback function in
seconds.
repeat (Optional[bool]): If this job should be periodically execute its callback function
(``True``) or only once (``False``). Defaults to ``True``
context (Optional[object]): Additional data needed for the callback function. Can be
accessed through ``job.context`` in the callback. Defaults to ``None``
"""
job_queue = None
def __init__(self, callback, interval, repeat=True, context=None):
self.callback = callback
self.interval = interval
self.repeat = repeat
self.context = context
self.name = callback.__name__
self._remove = Event()
self._enabled = Event()
self._enabled.set()
def run(self):
"""Executes the callback function"""
self.callback(self.job_queue.bot, self)
def schedule_removal(self):
"""
Schedules this job for removal from the ``JobQueue``. It will be removed without executing
its callback function again.
"""
self._remove.set()
def is_enabled(self):
return self._enabled.is_set()
def set_enabled(self, status):
if status:
self._enabled.set()
else:
self._enabled.clear()
enabled = property(is_enabled, set_enabled)
def __lt__(self, other):
return False