def start(self, schedule):
"""Start running function based on the provided schedule.
@param schedule: An object that provides or can be adapted to an
ISchedule interface.
@return: A Deferred whose callback will be invoked with
C{self} when C{self.stop} is called, or whose errback will be
invoked when the function raises an exception or returned a
deferred that has its errback invoked.
"""
assert not self.running, ("Tried to start an already running "
"Scheduled.")
self.schedule = ISchedule(schedule)
self.running = True
d = self.deferred = defer.Deferred()
self.starttime = self.clock.seconds()
self._lastTime = None
self._reschedule()
return d
def start(self, schedule):
"""Start running function based on the provided schedule.
@param schedule: An object that provides or can be adapted to an
ISchedule interface.
@return: A Deferred whose callback will be invoked with
C{self} when C{self.stop} is called, or whose errback will be
invoked when the function raises an exception or returned a
deferred that has its errback invoked.
"""
assert not self.running, ("Tried to start an already running "
"Scheduled.")
self.schedule = ISchedule(schedule)
self.running = True
d = self.deferred = defer.Deferred()
self.starttime = self.clock.seconds()
self._lastTime = None
self._reschedule()
return d
class ScheduledCall:
"""Call a function repeatedly.
If C{f} returns a deferred, rescheduling will not take place until the
deferred has fired. The result value is ignored.
@ivar f: The function to call.
@ivar a: A tuple of arguments to pass the function.
@ivar kw: A dictionary of keyword arguments to pass to the function.
@ivar clock: A provider of
L{twisted.internet.interfaces.IReactorTime}. The default is
L{twisted.internet.reactor}. Feel free to set this to
something else, but it probably ought to be set *before*
calling L{start}.
@type _lastTime: C{float}
@ivar _lastTime: The time at which this instance most recently scheduled
itself to run.
"""
call = None
running = False
deferred = None
schedule = None
_lastTime = 0.0
starttime = None
def __init__(self, f, *a, **kw):
self.f = f
self.a = a
self.kw = kw
from twisted.internet import reactor
self.clock = reactor
def start(self, schedule):
"""Start running function based on the provided schedule.
@param schedule: An object that provides or can be adapted to an
ISchedule interface.
@return: A Deferred whose callback will be invoked with
C{self} when C{self.stop} is called, or whose errback will be
invoked when the function raises an exception or returned a
deferred that has its errback invoked.
"""
assert not self.running, ("Tried to start an already running "
"Scheduled.")
self.schedule = ISchedule(schedule)
self.running = True
d = self.deferred = defer.Deferred()
self.starttime = self.clock.seconds()
self._lastTime = None
self._reschedule()
return d
def stop(self):
"""Stop running function.
"""
assert self.running, ("Tried to stop a ScheduledCall that was "
"not running.")
self.running = False
if self.call is not None:
self.call.cancel()
self.call = None
d, self.deferred = self.deferred, None
d.callback(self)
def __call__(self):
def cb(result):
if self.running:
self._reschedule()
else:
d, self.deferred = self.deferred, None
d.callback(self)
def eb(failure):
self.running = False
d, self.deferred = self.deferred, None
d.errback(failure)
self.call = None
d = defer.maybeDeferred(self.f, *self.a, **self.kw)
d.addCallback(cb)
d.addErrback(eb)
def _reschedule(self):
"""
Schedule the next iteration of this scheduled call.
"""
if self.call is None:
delay = self.schedule.getDelayForNext()
self._lastTime = self.clock.seconds() + delay
self.call = self.clock.callLater(delay, self)
def __repr__(self):
if hasattr(self.f, 'func_name'):
func = self.f.func_name
if hasattr(self.f, 'im_class'):
func = self.f.im_class.__name__ + '.' + func
else:
func = reflect.safe_repr(self.f)
return 'ScheduledCall<%s>(%s, *%s, **%s)' % (
self.schedule, func, reflect.safe_repr(self.a),
reflect.safe_repr(self.kw))
class ScheduledCall:
"""Call a function repeatedly.
If C{f} returns a deferred, rescheduling will not take place until the
deferred has fired. The result value is ignored.
@ivar f: The function to call.
@ivar a: A tuple of arguments to pass the function.
@ivar kw: A dictionary of keyword arguments to pass to the function.
@ivar clock: A provider of
L{twisted.internet.interfaces.IReactorTime}. The default is
L{twisted.internet.reactor}. Feel free to set this to
something else, but it probably ought to be set *before*
calling L{start}.
@type _lastTime: C{float}
@ivar _lastTime: The time at which this instance most recently scheduled
itself to run.
"""
call = None
running = False
deferred = None
schedule = None
_lastTime = 0.0
starttime = None
def __init__(self, f, *a, **kw):
self.f = f
self.a = a
self.kw = kw
from twisted.internet import reactor
self.clock = reactor
def start(self, schedule):
"""Start running function based on the provided schedule.
@param schedule: An object that provides or can be adapted to an
ISchedule interface.
@return: A Deferred whose callback will be invoked with
C{self} when C{self.stop} is called, or whose errback will be
invoked when the function raises an exception or returned a
deferred that has its errback invoked.
"""
assert not self.running, ("Tried to start an already running "
"Scheduled.")
self.schedule = ISchedule(schedule)
self.running = True
d = self.deferred = defer.Deferred()
self.starttime = self.clock.seconds()
self._lastTime = None
self._reschedule()
return d
def stop(self):
"""Stop running function.
"""
assert self.running, ("Tried to stop a ScheduledCall that was "
"not running.")
self.running = False
if self.call is not None:
self.call.cancel()
self.call = None
d, self.deferred = self.deferred, None
d.callback(self)
def __call__(self):
def cb(result):
if self.running:
self._reschedule()
else:
d, self.deferred = self.deferred, None
d.callback(self)
def eb(failure):
self.running = False
d, self.deferred = self.deferred, None
d.errback(failure)
self.call = None
d = defer.maybeDeferred(self.f, *self.a, **self.kw)
d.addCallback(cb)
d.addErrback(eb)
def _reschedule(self):
"""
Schedule the next iteration of this scheduled call.
"""
if self.call is None:
delay = self.schedule.getDelayForNext()
self._lastTime = self.clock.seconds() + delay
self.call = self.clock.callLater(delay, self)
def __repr__(self):
if hasattr(self.f, 'func_name'):
func = self.f.func_name
if hasattr(self.f, 'im_class'):
func = self.f.im_class.__name__ + '.' + func
else:
func = reflect.safe_repr(self.f)
return 'ScheduledCall<%s>(%s, *%s, **%s)' % (
self.schedule, func, reflect.safe_repr(
self.a), reflect.safe_repr(self.kw))
