"""
Defined states:
- * 0: The device is inactive.
- * ST_ACTIVE|ST_TRANSITION: The device is transitioning from inactive to active.
- * ST_ACTIVE: The device is active.
- * ST_TRANSITION: The device is transitioning from active to inactive.
+ - 0: The device is inactive.
+ - ST_ACTIVE|ST_TRANSITION: The device is transitioning from inactive to active.
+ - ST_ACTIVE: The device is active.
+ - ST_TRANSITION: The device is transitioning from active to inactive.
"""
+import logging
+
+from gi.repository import GObject
+
+logger = logging.getLogger("onoff.common")
+
ST_ACTIVE = 1
ST_TRANSITION = 2
def close(self):
self.device.notify.remove(self.changestate)
self.device.close()
+
+class ThrottledDevice(OnoffDevice):
+ """A device that delays the activation signal and the actual deactivation
+ by a fixed amounts of time. This limits the rate of state transitions to
+ two per offdelay."""
+ def __init__(self, device, ondelay, offdelay):
+ """
+ @type device: OnoffDevice
+ @type ondelay: int or float
+ @param ondelay: delay the report of ST_ACTIVE by this many seconds
+ @type offdelay: int or float
+ @param offdelay: delay the actual deactivation by this many seconds
+ """
+ OnoffDevice.__init__(self)
+ self.device = device
+ self.ondelay = ondelay
+ self.offdelay = offdelay
+ self.desired_state = 0
+ self.transition = None
+ self.device.notify.add(self.changestate)
+
+ @property
+ def state(self):
+ if self.transition is None:
+ return self.device.state
+ return self.desired_state | ST_TRANSITION
+
+ def _schedule_transition(self, delay, func):
+ assert self.transition is None
+ self.transition = GObject.timeout_add(int(1000 * delay), func)
+
+ def _cancel_transition(self):
+ assert self.transition is not None
+ ret = GObject.source_remove(self.transition)
+ assert ret
+ self.transition = None
+
+ def changestate(self, state):
+ if state != ST_ACTIVE:
+ OnoffDevice.changestate(self, state)
+ else:
+ if self.desired_state == 0:
+ logger.warn("device became active but we want inactive," +
+ "suppresing signal")
+ elif self.transition is None:
+ logger.debug("scheduling report of activation in %.1fs",
+ self.ondelay)
+ self._schedule_transition(self.ondelay, self._report_active)
+ else:
+ logger.debug("suppressing duplicate activation signal")
+
+ def _report_active(self):
+ assert self.desired_state == ST_ACTIVE
+ assert self.transition is not None
+ self.transition = None
+ logger.debug("delivering activation signal")
+ OnoffDevice.changestate(self, ST_ACTIVE)
+
+ def activate(self):
+ if self.desired_state == 0 and self.transition is not None:
+ logger.debug("cancelling pending deactivation")
+ self._cancel_transition()
+ curstate = self.device.state
+ if curstate == ST_ACTIVE:
+ self.desired_state = ST_ACTIVE
+ OnoffDevice.changestate(self, ST_ACTIVE)
+ return
+ logger.warn("device should be active during delayed deactivation" +
+ ", but is in state %d", curstate)
+ self.desired_state = ST_ACTIVE
+ self.device.activate()
+ self.changestate(self.device.state)
+
+ def _do_stop(self):
+ assert self.desired_state == 0
+ assert self.transition is not None
+ self.transition = None
+ logger.debug("actually deactivating")
+ self.device.deactivate()
+
+ def deactivate(self):
+ if self.desired_state == ST_ACTIVE and self.transition is not None:
+ logger.debug("cancelling pending activation report")
+ self._cancel_transition()
+ self.desired_state = 0
+ if self.transition is None:
+ logger.debug("scheduling actual deactivate in %.1fs",
+ self.offdelay)
+ self._schedule_transition(self.offdelay, self._do_stop)
+ self.changestate(self.state)
+ else:
+ logger.debug("not issuing deactivate due to pending deactivate")
+
+ def close(self):
+ if self.transition is not None:
+ logger.info("cancelling pending transition")
+ self._cancel_transition()
+ if self.desired_state == 0:
+ logger.info("invoking pending deactivate early during close")
+ self.device.deactivate()
+ self.device.notify.remove(self.changestate)
+ self.device.close()