Cleaned up the Scheduler.

This commit is contained in:
Lance Stout 2010-10-06 15:03:21 -04:00
parent 77b8f0f4bb
commit cbe76c8a70

View file

@ -1,14 +1,58 @@
"""
SleekXMPP: The Sleek XMPP Library
Copyright (C) 2010 Nathanael C. Fritz
This file is part of SleekXMPP.
See the file LICENSE for copying permission.
"""
import time
import threading
import logging
try: try:
import queue import queue
except ImportError: except ImportError:
import Queue as queue import Queue as queue
import time
import threading
import logging
class Task(object): class Task(object):
"""Task object for the Scheduler class"""
def __init__(self, name, seconds, callback, args=None, kwargs=None, repeat=False, qpointer=None): """
A scheduled task that will be executed by the scheduler
after a given time interval has passed.
Attributes:
name -- The name of the task.
seconds -- The number of seconds to wait before executing.
callback -- The function to execute.
args -- The arguments to pass to the callback.
kwargs -- The keyword arguments to pass to the callback.
repeat -- Indicates if the task should repeat.
Defaults to False.
qpointer -- A pointer to an event queue for queuing callback
execution instead of executing immediately.
Methods:
run -- Either queue or execute the callback.
reset -- Reset the task's timer.
"""
def __init__(self, name, seconds, callback, args=None,
kwargs=None, repeat=False, qpointer=None):
"""
Create a new task.
Arguments:
name -- The name of the task.
seconds -- The number of seconds to wait before executing.
callback -- The function to execute.
args -- The arguments to pass to the callback.
kwargs -- The keyword arguments to pass to the callback.
repeat -- Indicates if the task should repeat.
Defaults to False.
qpointer -- A pointer to an event queue for queuing callback
execution instead of executing immediately.
"""
self.name = name self.name = name
self.seconds = seconds self.seconds = seconds
self.callback = callback self.callback = callback
@ -19,6 +63,12 @@ class Task(object):
self.qpointer = qpointer self.qpointer = qpointer
def run(self): 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: if self.qpointer is not None:
self.qpointer.put(('schedule', self.callback, self.args)) self.qpointer.put(('schedule', self.callback, self.args))
else: else:
@ -27,11 +77,40 @@ class Task(object):
return self.repeat return self.repeat
def reset(self): def reset(self):
"""
Reset the task's timer so that it will repeat.
"""
self.next = time.time() + self.seconds self.next = time.time() + self.seconds
class Scheduler(object): class Scheduler(object):
"""Threaded scheduler that allows for updates mid-execution unlike http://docs.python.org/library/sched.html#module-sched"""
"""
A threaded scheduler that allows for updates mid-execution unlike the
scheduler in the standard library.
http://docs.python.org/library/sched.html#module-sched
Attributes:
addq -- A queue storing added tasks.
schedule -- A list of tasks in order of execution times.
thread -- If threaded, the thread processing the schedule.
run -- Indicates if the scheduler is running.
parentqueue -- A parent event queue in control of this scheduler.
Methods:
add -- Add a new task to the schedule.
process -- Process and schedule tasks.
quit -- Stop the scheduler.
"""
def __init__(self, parentqueue=None): def __init__(self, parentqueue=None):
"""
Create a new scheduler.
Arguments:
parentqueue -- A separate event queue controlling this scheduler.
"""
self.addq = queue.Queue() self.addq = queue.Queue()
self.schedule = [] self.schedule = []
self.thread = None self.thread = None
@ -39,13 +118,22 @@ class Scheduler(object):
self.parentqueue = parentqueue self.parentqueue = parentqueue
def process(self, threaded=True): def process(self, threaded=True):
"""
Begin accepting and processing scheduled tasks.
Arguments:
threaded -- Indicates if the scheduler should execute in its own
thread. Defaults to True.
"""
if threaded: if threaded:
self.thread = threading.Thread(name='shedulerprocess', target=self._process) self.thread = threading.Thread(name='sheduler_process',
target=self._process)
self.thread.start() self.thread.start()
else: else:
self._process() self._process()
def _process(self): def _process(self):
"""Process scheduled tasks."""
self.run = True self.run = True
while self.run: while self.run:
try: try:
@ -73,15 +161,35 @@ class Scheduler(object):
updated = True updated = True
self.schedule.append(newtask) self.schedule.append(newtask)
finally: finally:
if updated: self.schedule = sorted(self.schedule, key=lambda task: task.next) if updated:
self.schedule = sorted(self.schedule,
key=lambda task: task.next)
except KeyboardInterrupt: except KeyboardInterrupt:
self.run = False self.run = False
logging.debug("Qutting Scheduler thread") logging.debug("Qutting Scheduler thread")
if self.parentqueue is not None: if self.parentqueue is not None:
self.parentqueue.put(('quit', None, None)) self.parentqueue.put(('quit', None, None))
def add(self, name, seconds, callback, args=None, kwargs=None, repeat=False, qpointer=None): def add(self, name, seconds, callback, args=None,
self.addq.put(Task(name, seconds, callback, args, kwargs, repeat, qpointer)) kwargs=None, repeat=False, qpointer=None):
"""
Schedule a new task.
Arguments:
name -- The name of the task.
seconds -- The number of seconds to wait before executing.
callback -- The function to execute.
args -- The arguments to pass to the callback.
kwargs -- The keyword arguments to pass to the callback.
repeat -- Indicates if the task should repeat.
Defaults to False.
qpointer -- A pointer to an event queue for queuing callback
execution instead of executing immediately.
"""
self.addq.put(Task(name, seconds, callback, args,
kwargs, repeat, qpointer))
def quit(self): def quit(self):
"""Shutdown the scheduler."""
self.run = False self.run = False