/usr/lib/python3/dist-packages/sleekxmpp/xmlstream/scheduler.py is in python3-sleekxmpp 1.3.1-6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 | # -*- coding: utf-8 -*-
"""
sleekxmpp.xmlstream.scheduler
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This module provides a task scheduler that works better
with SleekXMPP's threading usage than the stock version.
Part of SleekXMPP: The Sleek XMPP Library
:copyright: (c) 2011 Nathanael C. Fritz
:license: MIT, see LICENSE for more details
"""
import time
import threading
import logging
import itertools
from sleekxmpp.util import Queue, QueueEmpty
#: The time in seconds to wait for events from the event queue, and also the
#: time between checks for the process stop signal.
WAIT_TIMEOUT = 1.0
log = logging.getLogger(__name__)
class Task(object):
"""
A scheduled task that will be executed by the scheduler
after a given time interval has passed.
:param string name: The name of the task.
:param int seconds: The number of seconds to wait before executing.
:param callback: The function to execute.
:param tuple args: The arguments to pass to the callback.
:param dict kwargs: The keyword arguments to pass to the callback.
:param bool repeat: Indicates if the task should repeat.
Defaults to ``False``.
:param pointer: A pointer to an event queue for queuing callback
execution instead of executing immediately.
"""
def __init__(self, name, seconds, callback, args=None,
kwargs=None, repeat=False, qpointer=None):
#: The name of the task.
self.name = name
#: The number of seconds to wait before executing.
self.seconds = seconds
#: The function to execute once enough time has passed.
self.callback = callback
#: The arguments to pass to :attr:`callback`.
self.args = args or tuple()
#: The keyword arguments to pass to :attr:`callback`.
self.kwargs = kwargs or {}
#: Indicates if the task should repeat after executing,
#: using the same :attr:`seconds` delay.
self.repeat = repeat
#: The time when the task should execute next.
self.next = time.time() + self.seconds
#: The main event queue, which allows for callbacks to
#: be queued for execution instead of executing immediately.
self.qpointer = qpointer
def run(self):
"""Execute the task's callback.
If an event queue was supplied, place the callback in the queue;
otherwise, execute the callback immediately.
"""
if self.qpointer is not None:
self.qpointer.put(('schedule', self.callback,
self.args, self.kwargs, self.name))
else:
self.callback(*self.args, **self.kwargs)
self.reset()
return self.repeat
def reset(self):
"""Reset the task's timer so that it will repeat."""
self.next = time.time() + self.seconds
class Scheduler(object):
"""
A threaded scheduler that allows for updates mid-execution unlike the
scheduler in the standard library.
Based on: http://docs.python.org/library/sched.html#module-sched
:param parentstop: An :class:`~threading.Event` to signal stopping
the scheduler.
"""
def __init__(self, parentstop=None):
#: A queue for storing tasks
self.addq = Queue()
#: A list of tasks in order of execution time.
self.schedule = []
#: If running in threaded mode, this will be the thread processing
#: the schedule.
self.thread = None
#: A flag indicating that the scheduler is running.
self.run = False
#: An :class:`~threading.Event` instance for signalling to stop
#: the scheduler.
self.stop = parentstop
#: Lock for accessing the task queue.
self.schedule_lock = threading.RLock()
#: The time in seconds to wait for events from the event queue,
#: and also the time between checks for the process stop signal.
self.wait_timeout = WAIT_TIMEOUT
def process(self, threaded=True, daemon=False):
"""Begin accepting and processing scheduled tasks.
:param bool threaded: Indicates if the scheduler should execute
in its own thread. Defaults to ``True``.
"""
if threaded:
self.thread = threading.Thread(name='scheduler_process',
target=self._process)
self.thread.daemon = daemon
self.thread.start()
else:
self._process()
def _process(self):
"""Process scheduled tasks."""
self.run = True
try:
while self.run and not self.stop.is_set():
updated = False
if self.schedule:
wait = self.schedule[0].next - time.time()
else:
wait = self.wait_timeout
try:
if wait <= 0.0:
newtask = self.addq.get(False)
else:
newtask = None
while self.run and \
not self.stop.is_set() and \
newtask is None and \
wait > 0:
try:
newtask = self.addq.get(True, min(wait, self.wait_timeout))
except QueueEmpty: # Nothing to add, nothing to do. Check run flags and continue waiting.
wait -= self.wait_timeout
except QueueEmpty: # Time to run some tasks, and no new tasks to add.
self.schedule_lock.acquire()
# select only those tasks which are to be executed now
relevant = itertools.takewhile(
lambda task: time.time() >= task.next, self.schedule)
# run the tasks and keep the return value in a tuple
status = map(lambda task: (task, task.run()), relevant)
# remove non-repeating tasks
for task, doRepeat in status:
if not doRepeat:
try:
self.schedule.remove(task)
except ValueError:
pass
else:
# only need to resort tasks if a repeated task has
# been kept in the list.
updated = True
else: # Add new task
self.schedule_lock.acquire()
if newtask is not None:
self.schedule.append(newtask)
updated = True
finally:
if updated:
self.schedule.sort(key=lambda task: task.next)
self.schedule_lock.release()
except KeyboardInterrupt:
self.run = False
except SystemExit:
self.run = False
log.debug("Quitting Scheduler thread")
def add(self, name, seconds, callback, args=None,
kwargs=None, repeat=False, qpointer=None):
"""Schedule a new task.
:param string name: The name of the task.
:param int seconds: The number of seconds to wait before executing.
:param callback: The function to execute.
:param tuple args: The arguments to pass to the callback.
:param dict kwargs: The keyword arguments to pass to the callback.
:param bool repeat: Indicates if the task should repeat.
Defaults to ``False``.
:param pointer: A pointer to an event queue for queuing callback
execution instead of executing immediately.
"""
try:
self.schedule_lock.acquire()
for task in self.schedule:
if task.name == name:
raise ValueError("Key %s already exists" % name)
self.addq.put(Task(name, seconds, callback, args,
kwargs, repeat, qpointer))
except:
raise
finally:
self.schedule_lock.release()
def remove(self, name):
"""Remove a scheduled task ahead of schedule, and without
executing it.
:param string name: The name of the task to remove.
"""
try:
self.schedule_lock.acquire()
the_task = None
for task in self.schedule:
if task.name == name:
the_task = task
if the_task is not None:
self.schedule.remove(the_task)
except:
raise
finally:
self.schedule_lock.release()
def quit(self):
"""Shutdown the scheduler."""
self.run = False
|