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[Sandbox-CVS] Sandbox/ianbicking/WebKit/TaskKit Properties.py,NONE,1.1 Scheduler.py,NONE,1.1 Task.py,NONE,1.1 TaskHandler.py,NONE,1.1 __init__.py,NONE,1.1
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From: <ian...@us...> - 2003-11-05 08:27:07
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Update of /cvsroot/webware-sandbox/Sandbox/ianbicking/WebKit/TaskKit
In directory sc8-pr-cvs1:/tmp/cvs-serv27696/TaskKit
Added Files:
Properties.py Scheduler.py Task.py TaskHandler.py __init__.py
Log Message:
Added WebKit-Standalone project.
--- NEW FILE: Properties.py ---
name = 'TaskKit'
version = ('X', 'Y', 0)
docs = [
{'name': "Quick Start", 'file': 'QuickStart.html'},
{'name': "User's Guide", 'file': 'UsersGuide.html'},
{'name': 'To Do', 'file': 'TODO-TaskKit.text'},
]
status = 'beta'
requiredPyVersion = (2, 0, 0)
synopsis = """TaskKit provides a framework for the scheduling and management of tasks which can be triggered periodically or at specific times."""
--- NEW FILE: Scheduler.py ---
"""
This is the TaskManager python package. It provides a system for running any number of
predefined tasks in separate threads in an organized and controlled manner.
A task in this package is a class derived from the Task class. The task should have a run
method that, when called, performs some task.
The Scheduler class is the organizing object. It manages the addition, execution, deletion,
and well being of a number of tasks. Once you have created your task class, you call the Scheduler to
get it added to the tasks to be run.
"""
from threading import Thread, Event
from TaskHandler import TaskHandler
from time import time, sleep
from exceptions import IOError
class Scheduler(Thread):
"""
The top level class of the TaskManager system. The Scheduler is a thread that
handles organizing and running tasks. The Sheduler class should be instantiated
to start a TaskManager sessions. It's run method should be called to start the
TaskManager. It's stop method should be called to end the TaskManager session.
"""
## Init ##
def __init__(self, daemon=1):
Thread.__init__(self)
self._notifyEvent = Event()
self._nextTime = None
self._scheduled = {}
self._running = {}
self._onDemand = {}
self._isRunning = 0
if daemon: self.setDaemon(1)
## Event Methods ##
def wait(self, seconds=None):
"""
Our own version of wait.
When called, it waits for the specified number of seconds, or until it is
notified that it needs to wake up, through the notify event.
"""
try:
self._notifyEvent.wait(seconds)
except IOError, e:
pass
self._notifyEvent.clear()
## Attributes ##
def runningTasks(self):
return self._running
def running(self, name, default=None):
"""
Returns a task with the given name from the "running" list,
if it is present there.
"""
return self._running.get(name, default)
def hasRunning(self, name):
"""
Check to see if a task with the given name is currently running.
"""
return self._running.has_key(name)
def setRunning(self, handle):
"""
Add a task to the running dictionary.
Used internally only.
"""
self._running[handle.name()] = handle
def delRunning(self, name):
"""
Delete a task from the running list.
Used Internally.
"""
try:
handle = self._running[name]
del self._running[name]
return handle
except:
return None
def scheduledTasks(self):
return self._scheduled
def scheduled(self, name, default=None):
"""
Returns a task from the scheduled list.
"""
return self._scheduled.get(name, default)
def hasScheduled(self, name):
"""
Is the task with he given name in the scheduled list?
"""
return self._scheduled.has_key(name)
def setScheduled(self, handle):
"""
Add the given task to the scheduled list.
"""
self._scheduled[handle.name()] = handle
def delScheduled(self, name):
"""
Deleted a task with the given name from the scheduled list.
"""
try:
handle = self._scheduled[name]
del self._scheduled[name]
return handle
except:
return None
def onDemandTasks(self):
return self._onDemand
def onDemand(self, name, default=None):
"""
Returns a task from the onDemand list.
"""
return self._onDemand.get(name, default)
def hasOnDemand(self, name):
"""
Is the task with he given name in the onDemand list?
"""
return self._onDemand.has_key(name)
def setOnDemand(self, handle):
"""
Add the given task to the onDemand list.
"""
self._onDemand[handle.name()] = handle
def delOnDemand(self, name):
"""
Deleted a task with the given name from the onDemand list.
"""
try:
handle = self._onDemand[name]
del self._onDemand[name]
return handle
except:
return None
def nextTime(self):
return self._nextTime
def setNextTime(self, time):
self._nextTime = time
def isRunning(self):
return self._isRunning
## Adding Tasks ##
def addTimedAction(self, time, task, name):
"""
This method is used to add an action to be run once, at a specific time.
"""
handle = self.unregisterTask(name)
if not handle:
handle = TaskHandler(self, time, 0, task, name)
else:
handle.reset(time, 0, task, 1)
self.scheduleTask(handle)
def addActionOnDemand(self, task, name):
"""
This method is used to add a task to the scheduler that will not be scheduled
until specifically requested.
"""
handle = self.unregisterTask(name)
if not handle:
handle = TaskHandler(self, time(), 0, task, name)
else:
handle.reset(time(), 0, task, 1)
self.setOnDemand(handle)
def addDailyAction(self, hour, minute, task, name):
""" This method is used to add an action to be run every day
at a specific time. If a task with the given name is already
registered with the scheduler, that task will be removed from
the scheduling queue and registered anew as a periodic task.
Can we make this addCalendarAction? What if we want to run
something once a week? We probably don't need that for
WebKit, but this is a more generally useful module. This
could be a difficult function, though. Particularly without
mxDateTime.
"""
import time
current = time.localtime(time.time())
currHour = current[3]
currMin = current[4]
if hour > currHour:
hourDifference = hour - currHour
if minute > currMin:
minuteDifference = minute - currMin
elif minute < currMin:
minuteDifference = 60 - currMin + minute
hourDifference -= 1
else:
minuteDifference = 0
elif hour < currHour:
hourDifference = 24 - currHour + hour
if minute > currMin:
minuteDifference = minute - currMin
elif minute < currMin:
minuteDifference = 60 - currMin + minute
hourDifference -= 1
else:
minuteDifference = 0
else:
if minute > currMin:
hourDifference = 0
minuteDifference = minute - currMin
elif minute < currMin:
minuteDifference = 60 - currMin + minute
hourDifference = 23
else:
hourDifference = 0
minuteDifference = 0
delay = (minuteDifference + (hourDifference * 60)) * 60
self.addPeriodicAction(time.time()+delay, 24*60*60, task, name)
def addPeriodicAction(self, start, period, task, name):
"""
This method is used to add an action to be run at a specific initial time,
and every period thereafter.
The scheduler will not reschedule a task until the last scheduled instance
of the task has completed.
If a task with the given name is already registered with the scheduler,
that task will be removed from the scheduling queue and registered
anew as a periodic task.
"""
handle = self.unregisterTask(name)
if not handle:
handle = TaskHandler(self, start, period, task, name)
else:
handle.reset(start, period, task, 1)
self.scheduleTask(handle)
## Task methods ##
def unregisterTask(self, name):
"""
This method unregisters the named task so that it can be rescheduled with
different parameters, or simply removed.
"""
handle = None
if self.hasScheduled(name):
handle = self.delScheduled(name)
if self.hasOnDemand(name):
handle = self.delOnDemand(name)
if handle:
handle.unregister()
return handle
def runTaskNow(self, name):
"""
This method is provided to allow a registered task to be immediately executed.
Returns 1 if the task is either currently running or was started, or 0 if the
task could not be found in the list of currently registered tasks.
"""
if self.hasRunning(name):
return 1
handle = self.scheduled(name)
if not handle:
handle = self.onDemand(name)
if not handle:
return 0
self.runTask(handle)
return 1
def demandTask(self, name):
"""
This method is provided to allow the server to request that a task listed as being
registered on-demand be run as soon as possible.
If the task is currently running, it will be flagged to run again as soon as the
current run completes.
Returns 0 if the task name could not be found on the on-demand or currently running lists.
"""
if not self.hasRunning(name) and not self.hasOnDemand(name):
return 0
else:
handle = self.running(name)
if handle:
handle.runOnCompletion()
return 1
handle = self.onDemand(name)
if not handle:
return 0
self.runTask(handle)
return 1
def stopTask(self, name):
"""
This method is provided to put an immediate halt to a running background task.
Returns 1 if the task was either not running, or was running and was told to stop.
"""
handle = self.running(name)
if not handle:
return 0
handle.stop()
return 1
def stopAllTasks(self):
"""
Terminate all running tasks.
"""
for i in self._running.keys():
print "Stopping ",i
self.stopTask(i)
def disableTask(self, name):
"""
This method is provided to specify that a task be suspended. Suspended tasks will
not be scheduled until later enabled. If the task is currently running, it will
not be interfered with, but the task will not be scheduled for execution in future
until re-enabled.
Returns 1 if the task was found and disabled.
"""
handle = self.running(name)
if not handle:
handle = self.scheduled(name)
if not handle:
return 0
handle.disable()
return 1
def enableTask(self, name):
"""
This method is provided to specify that a task be re-enabled after a suspension.
A re-enabled task will be scheduled for execution according to its original schedule,
with any runtimes that would have been issued during the time the task was suspended
simply skipped.
Returns 1 if the task was found and enabled
"""
handle = self.running(name)
if not handle:
handle = self.scheduled(name)
if not handle:
return 0
handle.enable()
return 1
def runTask(self, handle):
"""
This method is used by the Scheduler thread's main loop to put a task in
the scheduled hash onto the run hash.
"""
name = handle.name()
if self.delScheduled(name) or self.delOnDemand(name):
self.setRunning(handle)
handle.runTask()
def scheduleTask(self, handle):
"""
This method takes a task that needs to be scheduled and adds it to the scheduler.
All scheduling additions or changes are handled by this method. This is the only
Scheduler method that can notify the run() method that it may need to wake up early
to handle a newly registered task.
"""
self.setScheduled(handle)
if not self.nextTime() or handle.startTime() < self.nextTime():
self.setNextTime(handle.startTime())
self.notify()
## Misc Methods ##
def notifyCompletion(self, handle):
"""
This method is used by instances of TaskHandler to let the Scheduler thread know
when their tasks have run to completion.
This method is responsible for rescheduling the task if it is a periodic task.
"""
name = handle.name()
if self.hasRunning(name):
self.delRunning(name)
if handle.startTime() and handle.startTime() > time():
self.scheduleTask(handle)
else:
if handle.reschedule():
self.scheduleTask(handle)
elif not handle.startTime():
self.setOnDemand(handle)
if handle.runAgain():
self.runTask(handle)
def notify(self):
self._notifyEvent.set()
def stop(self):
"""
This method terminates the scheduler and its associated tasks.
"""
self._isRunning = 0
self.notify()
self.stopAllTasks()
self.join() # jdh: wait until the scheduler thread exits; otherwise
# it's possible for the interpreter to exit before this thread
# has a chance to shut down completely, which causes a traceback
## Main Method ##
def run(self):
"""
This method is responsible for carrying out the scheduling work of this class
on a background thread. The basic logic is to wait until the next action is due to
run, move the task from our scheduled list to our running list, and run it. Other
synchronized methods such as runTask(), scheduleTask(), and notifyCompletion(), may
be called while this method is waiting for something to happen. These methods modify
the data structures that run() uses to determine its scheduling needs.
"""
self._isRunning = 1
while 1:
if not self._isRunning:
return
if not self.nextTime():
self.wait()
else:
nextTime = self.nextTime()
currentTime = time()
if currentTime < nextTime:
sleepTime = nextTime - currentTime
self.wait(sleepTime)
if not self._isRunning: return
currentTime = time()
if currentTime >= nextTime:
toRun = []
nextRun = None
for handle in self._scheduled.values():
startTime = handle.startTime()
if startTime <= currentTime:
toRun.append(handle)
else:
if not nextRun:
nextRun = startTime
elif startTime < nextRun:
nextRun = startTime
self.setNextTime(nextRun)
for handle in toRun:
self.runTask(handle)
--- NEW FILE: Task.py ---
from WebKit.MiscUtils import AbstractError
class Task:
def __init__(self):
""" Subclasses should invoke super for this method. """
# Nothing for now, but we might do something in the future.
pass
def run(self):
"""
Override this method for you own tasks. Long running tasks can periodically
use the proceed() method to check if a task should stop.
"""
raise AbstractError, self.__class__
## Utility method ##
def proceed(self):
"""
Should this task continue running?
Should be called periodically by long tasks to check if the system wants them to exit.
Returns 1 if its OK to continue, 0 if its time to quit
"""
return self._handle._isRunning
## Attributes ##
def handle(self):
"""
A task is scheduled by wrapping a handler around it. It knows
everything about the scheduling (periodicity and the like).
Under normal circumstances you should not need the handler,
but if you want to write period modifying run() methods,
it is useful to have access to the handler. Use it with care.
"""
return self._handle
def name(self):
"""
Returns the unique name under which the task was scheduled.
"""
return self._name
## Private method ##
def _run(self, handle):
"""
This is the actual run method for the Task thread. It is a private method which
should not be overriden.
"""
self._name = handle.name()
self._handle = handle
self.run()
handle.notifyCompletion()
--- NEW FILE: TaskHandler.py ---
from time import time, sleep
from threading import Event, Thread
class TaskHandler:
"""
While the Task class only knows what task to perform with the run()-method,
the TaskHandler has all the knowledge about the periodicity of the task.
Instances of this class are managed by the Scheduler in the
scheduled, running and onDemand dictionaries.
"""
## Init ##
def __init__(self, scheduler, start, period, task, name):
self._scheduler = scheduler
self._task = task
self._name = name
self._thread = None
self._isRunning = 0
self._suspend = 0
self._lastTime = None
self._startTime = start
self._registerTime = time()
self._reregister = 1
self._rerun = 0
self._period = abs(period)
## Scheduling ##
def reset(self, start, period, task, reregister):
self._startTime = start
self._period = abs(period)
self._task = task
self._reregister = reregister
def runTask(self):
"""
Runs this task in a background thread.
"""
if self._suspend:
self._scheduler.notifyCompletion(self)
return
self._rerun = 0
self._thread = Thread(None, self._task._run, self.name(), (self,))
self._isRunning = 1
self._thread.start()
def reschedule(self):
"""
Method to determine whether this task should be rescheduled. Increments the
startTime and returns true if this is a periodically executed task.
"""
if self._period == 0:
return 0
else:
if self._lastTime - self._startTime > self._period: #if the time taken to run the task exceeds the period
self._startTime = self._lastTime + self._period
else:
self._startTime = self._startTime + self._period
return 1
def notifyCompletion(self):
self._isRunning = 0
self._lastTime = time()
self._scheduler.notifyCompletion(self)
## Attributes ##
def isRunning(self):
return self._isRunning
def runAgain(self):
"""
This method lets the Scheduler check to see whether this task should be
re-run when it terminates
"""
return self._rerun
def isOnDemand(self):
"""
Returns true if this task is not scheduled for periodic execution.
"""
return self._period == 1
def runOnCompletion(self):
"""
Method to request that this task be re-run after its current completion.
Intended for on-demand tasks that are requested by the Scheduler while
they are already running.
"""
self._rerun = 1
def unregister(self):
"""
Method to request that this task not be kept after its current completion.
Used to remove a task from the scheduler
"""
self._reregister = 0
self._rerun = 0
def disable(self):
"""
Method to disable future invocations of this task.
"""
self._suspend = 1
def enable(self):
"""
Method to enable future invocations of this task.
"""
self._suspend = 0
def period(self):
"""
Returns the period of this task.
"""
return self._period
def setPeriod(self, period):
"""
Mmethod to change the period for this task.
"""
self._period = period
def stop(self):
self._isRunning = 0
def name(self):
return self._name
def startTime(self, newTime=None):
if newTime:
self._startTime = newTime
return self._startTime
--- NEW FILE: __init__.py ---
def InstallInWebKit(appserver):
pass
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