Introduce MessageQueue (#537)

* Introduce MessageQueue

* minor documentation and terminology fixes according to the review

* minor documentation and terminology fixes according to the review

* minor documentation and terminology fixes according to the review

* pep8 fix
This commit is contained in:
thodnev 2017-03-15 18:35:33 +02:00 committed by Jannes Höke
parent 85b9236641
commit 22142e7cbd
5 changed files with 430 additions and 0 deletions

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@ -41,6 +41,7 @@ The following wonderful people contributed directly or indirectly to this projec
- `Joscha Götzer <https://github.com/Rostgnom>`_
- `Shelomentsev D <https://github.com/shelomentsevd>`_
- `sooyhwang <https://github.com/sooyhwang>`_
- `thodnev <https://github.com/thodnev>`_
- `Valentijn <https://github.com/Faalentijn>`_
- `voider1 <https://github.com/voider1>`_
- `wjt <https://github.com/wjt>`_

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@ -0,0 +1,7 @@
telegram.ext.messagequeue module
================================
.. automodule:: telegram.ext.messagequeue
:members:
:undoc-members:
:show-inheritance:

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@ -16,6 +16,7 @@ Submodules
telegram.ext.commandhandler
telegram.ext.inlinequeryhandler
telegram.ext.messagehandler
telegram.ext.messagequeue
telegram.ext.filters
telegram.ext.regexhandler
telegram.ext.stringcommandhandler

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@ -0,0 +1,330 @@
#!/usr/bin/env python
#
# Module author:
# Tymofii A. Khodniev (thodnev) <thodnev@mail.ru>
#
# A library that provides a Python interface to the Telegram Bot API
# Copyright (C) 2015-2017
# 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/]
'''A throughput-limiting message processor for Telegram bots'''
from telegram.utils import promise
import functools
import sys
import time
import threading
if sys.version_info.major > 2:
import queue as q
else:
import Queue as q
# We need to count < 1s intervals, so the most accurate timer is needed
# Starting from Python 3.3 we have time.perf_counter which is the clock
# with the highest resolution available to the system, so let's use it there.
# In Python 2.7, there's no perf_counter yet, so fallback on what we have:
# on Windows, the best available is time.clock while time.time is on
# another platforms (M. Lutz, "Learning Python," 4ed, p.630-634)
if sys.version_info.major == 3 and sys.version_info.minor >= 3:
curtime = time.perf_counter
else:
curtime = time.clock if sys.platform[:3] == 'win' else time.time
class DelayQueueError(RuntimeError):
'''Indicates processing errors'''
pass
class DelayQueue(threading.Thread):
'''Processes callbacks from queue with specified throughput limits.
Creates a separate thread to process callbacks with delays.
Args:
queue (:obj:`queue.Queue`, optional): used to pass callbacks to
thread.
Creates `queue.Queue` implicitly if not provided.
burst_limit (:obj:`int`, optional): number of maximum callbacks to
process per time-window defined by `time_limit_ms`.
Defaults to 30.
time_limit_ms (:obj:`int`, optional): defines width of time-window
used when each processing limit is calculated.
Defaults to 1000.
exc_route (:obj:`callable`, optional): a callable, accepting 1
positional argument; used to route exceptions from processor
thread to main thread; is called on `Exception` subclass
exceptions.
If not provided, exceptions are routed through dummy handler,
which re-raises them.
autostart (:obj:`bool`, optional): if True, processor is started
immediately after object's creation; if False, should be
started manually by `start` method.
Defaults to True.
name (:obj:`str`, optional): thread's name.
Defaults to ``'DelayQueue-N'``, where N is sequential
number of object created.
'''
_instcnt = 0 # instance counter
def __init__(self,
queue=None,
burst_limit=30,
time_limit_ms=1000,
exc_route=None,
autostart=True,
name=None):
self._queue = queue if queue is not None else q.Queue()
self.burst_limit = burst_limit
self.time_limit = time_limit_ms / 1000
self.exc_route = (exc_route if exc_route is not None else self._default_exception_handler)
self.__exit_req = False # flag to gently exit thread
self.__class__._instcnt += 1
if name is None:
name = '%s-%s' % (self.__class__.__name__, self.__class__._instcnt)
super(DelayQueue, self).__init__(name=name)
self.daemon = False
if autostart: # immediately start processing
super(DelayQueue, self).start()
def run(self):
'''Do not use the method except for unthreaded testing purposes,
the method normally is automatically called by `start` method.
'''
times = [] # used to store each callable processing time
while True:
item = self._queue.get()
if self.__exit_req:
return # shutdown thread
# delay routine
now = curtime()
t_delta = now - self.time_limit # calculate early to improve perf.
if times and t_delta > times[-1]:
# if last call was before the limit time-window
# used to impr. perf. in long-interval calls case
times = [now]
else:
# collect last in current limit time-window
times = [t for t in times if t >= t_delta]
times.append(now)
if len(times) >= self.burst_limit: # if throughput limit was hit
time.sleep(times[1] - t_delta)
# finally process one
try:
func, args, kwargs = item
func(*args, **kwargs)
except Exception as exc: # re-route any exceptions
self.exc_route(exc) # to prevent thread exit
def stop(self, timeout=None):
'''Used to gently stop processor and shutdown its thread.
Args:
timeout (:obj:`float`): indicates maximum time to wait for
processor to stop and its thread to exit.
If timeout exceeds and processor has not stopped, method
silently returns. `is_alive` could be used afterwards
to check the actual status. If `timeout` set to None, blocks
until processor is shut down.
Defaults to None.
Returns:
None
'''
self.__exit_req = True # gently request
self._queue.put(None) # put something to unfreeze if frozen
super(DelayQueue, self).join(timeout=timeout)
@staticmethod
def _default_exception_handler(exc):
'''Dummy exception handler which re-raises exception in thread.
Could be possibly overwritten by subclasses.
'''
raise exc
def __call__(self, func, *args, **kwargs):
'''Used to process callbacks in throughput-limiting thread
through queue.
Args:
func (:obj:`callable`): the actual function (or any callable) that
is processed through queue.
*args: variable-length `func` arguments.
**kwargs: arbitrary keyword-arguments to `func`.
Returns:
None
'''
if not self.is_alive() or self.__exit_req:
raise DelayQueueError('Could not process callback in stopped thread')
self._queue.put((func, args, kwargs))
# The most straightforward way to implement this is to use 2 sequenital delay
# queues, like on classic delay chain schematics in electronics.
# So, message path is:
# msg --> group delay if group msg, else no delay --> normal msg delay --> out
# This way OS threading scheduler cares of timings accuracy.
# (see time.time, time.clock, time.perf_counter, time.sleep @ docs.python.org)
class MessageQueue(object):
'''Implements callback processing with proper delays to avoid hitting
Telegram's message limits.
Contains two `DelayQueue`s, for group and for all messages, interconnected
in delay chain. Callables are processed through *group* `DelayQueue`, then
through *all* `DelayQueue` for group-type messages. For non-group messages,
only the *all* `DelayQueue` is used.
Args:
all_burst_limit (:obj:`int`, optional): numer of maximum *all-type*
callbacks to process per time-window defined by
`all_time_limit_ms`.
Defaults to 30.
all_time_limit_ms (:obj:`int`, optional): defines width of *all-type*
time-window used when each processing limit is calculated.
Defaults to 1000 ms.
group_burst_limit (:obj:`int`, optional): numer of maximum *group-type*
callbacks to process per time-window defined by
`group_time_limit_ms`.
Defaults to 20.
group_time_limit_ms (:obj:`int`, optional): defines width of
*group-type* time-window used when each processing limit is
calculated.
Defaults to 60000 ms.
exc_route (:obj:`callable`, optional): a callable, accepting one
positional argument; used to route exceptions from processor
threads to main thread; is called on `Exception` subclass
exceptions.
If not provided, exceptions are routed through dummy handler,
which re-raises them.
autostart (:obj:`bool`, optional): if True, processors are started
immediately after object's creation; if False, should be
started manually by `start` method.
Defaults to True.
Attributes:
_all_delayq (:obj:`telegram.ext.messagequeue.DelayQueue`): actual
`DelayQueue` used for *all-type* callback processing
_group_delayq (:obj:`telegram.ext.messagequeue.DelayQueue`): actual
`DelayQueue` used for *group-type* callback processing
'''
def __init__(self,
all_burst_limit=30,
all_time_limit_ms=1000,
group_burst_limit=20,
group_time_limit_ms=60000,
exc_route=None,
autostart=True):
# create accoring delay queues, use composition
self._all_delayq = DelayQueue(
burst_limit=all_burst_limit,
time_limit_ms=all_time_limit_ms,
exc_route=exc_route,
autostart=autostart)
self._group_delayq = DelayQueue(
burst_limit=group_burst_limit,
time_limit_ms=group_time_limit_ms,
exc_route=exc_route,
autostart=autostart)
def start(self):
'''Method is used to manually start the `MessageQueue` processing
Returns:
None
'''
self._all_delayq.start()
self._group_delayq.start()
def stop(self, timeout=None):
self._group_delayq.stop(timeout=timeout)
self._all_delayq.stop(timeout=timeout)
stop.__doc__ = DelayQueue.stop.__doc__ or '' # reuse docsting if any
def __call__(self, promise, is_group_msg=False):
'''Processes callables in troughput-limiting queues to avoid
hitting limits (specified with \*_burst_limit and *\_time_limit_ms).
Args:
promise (:obj:`callable`): mainly the
:obj:`telegram.utils.promise.Promise` (see Notes for other
callables), that is processed in delay queues
is_group_msg (:obj:`bool`, optional): defines whether `promise`
would be processed in *group*+*all* `DelayQueue`s
(if set to ``True``), or only through *all* `DelayQueue`
(if set to ``False``), resulting in needed delays to avoid
hitting specified limits.
Defaults to ``True``.
Notes:
Method is designed to accept :obj:`telegram.utils.promise.Promise`
as `promise` argument, but other callables could be used too.
For example, lambdas or simple functions could be used to wrap
original func to be called with needed args.
In that case, be sure that either wrapper func does not raise
outside exceptions or the proper `exc_route` handler is provided.
Returns:
:obj:`callable` used as `promise` argument.
'''
if not is_group_msg: # ignore middle group delay
self._all_delayq(promise)
else: # use middle group delay
self._group_delayq(self._all_delayq, promise)
return promise
def queuedmessage(method):
'''A decorator to be used with `telegram.bot.Bot` send* methods.
Note:
As it probably wouldn't be a good idea to make this decorator a
property, it had been coded as decorator function, so it implies that
**first positional argument to wrapped MUST be self**\.
The next object attributes are used by decorator:
Attributes:
self._is_messages_queued_default (:obj:`bool`): Value to provide
class-defaults to `queued` kwarg if not provided during wrapped
method call.
self._msg_queue (:obj:`telegram.ext.messagequeue.MessageQueue`):
The actual `MessageQueue` used to delay outbond messages according
to specified time-limits.
Wrapped method starts accepting the next kwargs:
Args:
queued (:obj:`bool`, optional): if set to ``True``, the `MessageQueue`
is used to process output messages.
Defaults to `self._is_queued_out`.
isgroup (:obj:`bool`, optional): if set to ``True``, the message is
meant to be group-type (as there's no obvious way to determine its
type in other way at the moment). Group-type messages could have
additional processing delay according to limits set in
`self._out_queue`.
Defaults to ``False``.
Returns:
Either :obj:`telegram.utils.promise.Promise` in case call is queued,
or original method's return value if it's not.
'''
@functools.wraps(method)
def wrapped(self, *args, **kwargs):
queued = kwargs.pop('queued', self._is_messages_queued_default)
isgroup = kwargs.pop('isgroup', False)
if queued:
prom = promise.Promise(method, args, kwargs)
return self._msg_queue(prom, isgroup)
return method(self, *args, **kwargs)
return wrapped

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@ -0,0 +1,91 @@
'''This module contains telegram.ext.messagequeue test logic'''
from __future__ import print_function, division
import sys
import os
import time
import unittest
sys.path.insert(0, os.path.dirname(__file__) + os.sep + '..')
from tests.base import BaseTest
from telegram.ext import messagequeue as mq
class DelayQueueTest(BaseTest, unittest.TestCase):
def __init__(self, *args, **kwargs):
self._N = kwargs.pop('N', 128)
self._msglimit = kwargs.pop('burst_limit', 30)
self._timelimit = kwargs.pop('time_limit_ms', 1000)
self._margin = kwargs.pop('margin_ms', 0)
isprint = kwargs.pop('isprint', False)
def noprint(*args, **kwargs):
pass
self._print = print if isprint else noprint
super(DelayQueueTest, self).__init__(*args, **kwargs)
def setUp(self):
print = self._print
print('Self-test with N = {} msgs, burst_limit = {} msgs, '
'time_limit = {:.2f} ms, margin = {:.2f} ms'
''.format(self._N, self._msglimit, self._timelimit, self._margin))
self.testtimes = []
def testcall():
self.testtimes.append(mq.curtime())
self.testcall = testcall
def test_delayqueue_limits(self):
'''Test that DelayQueue dispatched calls don't hit time-window limit'''
print = self._print
dsp = mq.DelayQueue(
burst_limit=self._msglimit, time_limit_ms=self._timelimit, autostart=True)
print('Started dispatcher {}\nStatus: {}'
''.format(dsp, ['inactive', 'active'][dsp.is_alive()]))
self.assertTrue(dsp.is_alive())
print('Dispatching {} calls @ {}'.format(self._N, time.asctime()))
for i in range(self._N):
dsp(self.testcall)
print('Queue filled, waiting 4 dispatch finish @ ' + str(time.asctime()))
starttime = mq.curtime()
app_endtime = (
(self._N * self._msglimit /
(1000 * self._timelimit)) + starttime + 20) # wait up to 20 sec more than needed
while not dsp._queue.empty() and mq.curtime() < app_endtime:
time.sleep(1)
self.assertTrue(dsp._queue.empty()) # check loop exit condition
dsp.stop()
print('Dispatcher ' + ['stopped', '!NOT STOPPED!'][dsp.is_alive()] + ' @ ' + str(
time.asctime()))
self.assertFalse(dsp.is_alive())
self.assertTrue(self.testtimes or self._N == 0)
print('Calculating call time windows')
passes, fails = [], []
delta = (self._timelimit - self._margin) / 1000
it = enumerate(range(self._msglimit + 1, len(self.testtimes)))
for start, stop in it:
part = self.testtimes[start:stop]
if (part[-1] - part[0]) >= delta:
passes.append(part)
else:
fails.append(part)
print('Tested: {}, Passed: {}, Failed: {}'
''.format(len(passes + fails), len(passes), len(fails)))
if fails:
print('(!) Got mismatches: ' + ';\n'.join(map(str, fails)))
self.assertFalse(fails)
if __name__ == '__main__':
unittest.main()