Adding fancier version checks to allow to the cache to be preserved longer
[theonering] / src / gvoice / state_machine.py
index 6b0a58d..6d184d0 100644 (file)
 #!/usr/bin/env python
 
-"""
-@todo Look into switching from POLL_TIME = min(F * 2^n, MAX) to POLL_TIME = min(CONST + F * 2^n, MAX)
-@todo Look into supporting more states that have a different F and MAX
-"""
-
 import logging
 
-import gobject
-
 import util.go_utils as gobject_utils
 import util.coroutines as coroutines
-import gtk_toolbox
+import util.misc as misc_utils
 
 
-_moduleLogger = logging.getLogger("gvoice.state_machine")
+_moduleLogger = logging.getLogger(__name__)
 
 
-def _to_milliseconds(**kwd):
+def to_milliseconds(**kwd):
        if "milliseconds" in kwd:
                return kwd["milliseconds"]
        elif "seconds" in kwd:
                return kwd["seconds"] * 1000
        elif "minutes" in kwd:
                return kwd["minutes"] * 1000 * 60
+       elif "hours" in kwd:
+               return kwd["hours"] * 1000 * 60 * 60
        raise KeyError("Unknown arg: %r" % kwd)
 
 
+def to_seconds(**kwd):
+       if "milliseconds" in kwd:
+               return kwd["milliseconds"] / 1000
+       elif "seconds" in kwd:
+               return kwd["seconds"]
+       elif "minutes" in kwd:
+               return kwd["minutes"] * 60
+       elif "hours" in kwd:
+               return kwd["hours"] * 60 * 60
+       raise KeyError("Unknown arg: %r" % kwd)
+
+
+class NopStateStrategy(object):
+
+       def __init__(self):
+               pass
+
+       def initialize_state(self):
+               pass
+
+       def reinitialize_state(self):
+               pass
+
+       def increment_state(self):
+               pass
+
+       @property
+       def timeout(self):
+               return UpdateStateMachine.INFINITE_PERIOD
+
+       def __repr__(self):
+               return "NopStateStrategy()"
+
+
+class ConstantStateStrategy(object):
+
+       def __init__(self, timeout):
+               assert 0 < timeout or timeout == UpdateStateMachine.INFINITE_PERIOD
+               self._timeout = timeout
+
+       def initialize_state(self):
+               pass
+
+       def reinitialize_state(self):
+               pass
+
+       def increment_state(self):
+               pass
+
+       @property
+       def timeout(self):
+               return self._timeout
+
+       def __repr__(self):
+               return "ConstantStateStrategy(timeout=%r)" % self._timeout
+
+
+class NTimesStateStrategy(object):
+
+       def __init__(self, timeouts, postTimeout):
+               assert 0 < len(timeouts)
+               for timeout in timeouts:
+                       assert 0 < timeout or timeout == UpdateStateMachine.INFINITE_PERIOD
+               assert 0 < postTimeout or postTimeout == UpdateStateMachine.INFINITE_PERIOD
+               self._timeouts = timeouts
+               self._postTimeout = postTimeout
+
+               self._attemptCount = 0
+
+       def initialize_state(self):
+               self._attemptCount = len(self._timeouts)
+
+       def reinitialize_state(self):
+               self._attemptCount = 0
+
+       def increment_state(self):
+               self._attemptCount += 1
+
+       @property
+       def timeout(self):
+               try:
+                       return self._timeouts[self._attemptCount]
+               except IndexError:
+                       return self._postTimeout
+
+       def __str__(self):
+               return "NTimesStateStrategy(timeout=%r)" % (
+                       self.timeout,
+               )
+
+       def __repr__(self):
+               return "NTimesStateStrategy(timeouts=%r, postTimeout=%r)" % (
+                       self._timeouts,
+                       self._postTimeout,
+               )
+
+
+class GeometricStateStrategy(object):
+
+       def __init__(self, init, min, max):
+               assert 0 < init and init < max or init == UpdateStateMachine.INFINITE_PERIOD
+               assert 0 < min or min == UpdateStateMachine.INFINITE_PERIOD
+               assert min < max or max == UpdateStateMachine.INFINITE_PERIOD
+               self._min = min
+               self._max = max
+               self._init = init
+               self._current = 0
+
+       def initialize_state(self):
+               self._current = self._max
+
+       def reinitialize_state(self):
+               self._current = self._min
+
+       def increment_state(self):
+               if self._current == UpdateStateMachine.INFINITE_PERIOD:
+                       pass
+               if self._init == UpdateStateMachine.INFINITE_PERIOD:
+                       self._current = UpdateStateMachine.INFINITE_PERIOD
+               elif self._max == UpdateStateMachine.INFINITE_PERIOD:
+                       self._current *= 2
+               else:
+                       self._current = min(2 * self._current, self._max - self._init)
+
+       @property
+       def timeout(self):
+               if UpdateStateMachine.INFINITE_PERIOD in (self._init, self._current):
+                       timeout = UpdateStateMachine.INFINITE_PERIOD
+               else:
+                       timeout = self._init + self._current
+               return timeout
+
+       def __str__(self):
+               return "GeometricStateStrategy(timeout=%r)" % (
+                       self.timeout
+               )
+
+       def __repr__(self):
+               return "GeometricStateStrategy(init=%r, min=%r, max=%r)" % (
+                       self._init, self._min, self._max
+               )
+
+
 class StateMachine(object):
 
        STATE_ACTIVE = 0, "active"
        STATE_IDLE = 1, "idle"
        STATE_DND = 2, "dnd"
 
-       _ACTION_UPDATE = "update"
-       _ACTION_RESET = "reset"
-       _ACTION_STOP = "stop"
+       def start(self):
+               raise NotImplementedError("Abstract")
+
+       def stop(self):
+               raise NotImplementedError("Abstract")
+
+       def close(self):
+               raise NotImplementedError("Abstract")
+
+       def set_state(self, state):
+               raise NotImplementedError("Abstract")
+
+       @property
+       def state(self):
+               raise NotImplementedError("Abstract")
+
+
+class MasterStateMachine(StateMachine):
+
+       def __init__(self):
+               self._machines = []
+               self._state = self.STATE_ACTIVE
+
+       def append_machine(self, machine):
+               self._machines.append(machine)
 
-       _INITIAL_ACTIVE_PERIOD = int(_to_milliseconds(seconds=5))
-       _FINAL_ACTIVE_PERIOD = int(_to_milliseconds(minutes=2))
-       _IDLE_PERIOD = int(_to_milliseconds(minutes=10))
-       _INFINITE_PERIOD = -1
+       def start(self):
+               # Confirm we are all on the same page
+               for machine in self._machines:
+                       machine.set_state(self._state)
+               for machine in self._machines:
+                       machine.start()
+
+       def stop(self):
+               for machine in self._machines:
+                       machine.stop()
+
+       def close(self):
+               for machine in self._machines:
+                       machine.close()
+
+       def set_state(self, state):
+               self._state = state
+               for machine in self._machines:
+                       machine.set_state(state)
+
+       @property
+       def state(self):
+               return self._state
+
+
+class UpdateStateMachine(StateMachine):
+       # Making sure the it is initialized is finicky, be careful
+
+       INFINITE_PERIOD = -1
+       DEFAULT_MAX_TIMEOUT = to_seconds(hours=24)
 
        _IS_DAEMON = True
 
-       def __init__(self, initItems, updateItems):
-               self._initItems = initItems
+       def __init__(self, updateItems, name="", maxTime = DEFAULT_MAX_TIMEOUT):
+               self._name = name
                self._updateItems = updateItems
+               self._maxTime = maxTime
+               self._isActive = False
 
                self._state = self.STATE_ACTIVE
-               self._timeoutId = None
-               self._currentPeriod = self._INITIAL_ACTIVE_PERIOD
-               self._set_initial_period()
+               self._onTimeout = gobject_utils.Timeout(self._on_timeout)
 
+               self._strategies = {}
                self._callback = coroutines.func_sink(
                        coroutines.expand_positional(
                                self._request_reset_timers
                        )
                )
 
-       def close(self):
-               self._callback = None
+       def __str__(self):
+               return """UpdateStateMachine(
+       name=%r,
+       strategie=%s,
+       isActive=%r,
+       isPolling=%r,
+)""" % (self._name, self._strategy, self._isActive, self._onTimeout.is_running())
+
+       def __repr__(self):
+               return """UpdateStateMachine(
+       name=%r,
+       strategie=%r,
+)""" % (self._name, self._strategies)
+
+       def set_state_strategy(self, state, strategy):
+               self._strategies[state] = strategy
 
-       @gobject_utils.async
-       @gtk_toolbox.log_exception(_moduleLogger)
        def start(self):
-               _moduleLogger.info("Starting State Machine")
-               for item in self._initItems:
-                       try:
-                               item.update()
-                       except Exception:
-                               _moduleLogger.exception("Initial update failed for %r" % item)
-               self._schedule_update()
+               for strategy in self._strategies.itervalues():
+                       strategy.initialize_state()
+               if self._strategy.timeout != self.INFINITE_PERIOD:
+                       self._onTimeout.start(seconds=0)
+               self._isActive = True
+               _moduleLogger.info("%s Starting State Machine" % (self._name, ))
 
        def stop(self):
-               _moduleLogger.info("Stopping an already stopped state machine")
-               self._stop_update()
+               _moduleLogger.info("%s Stopping State Machine" % (self._name, ))
+               self._isActive = False
+               self._onTimeout.cancel()
+
+       def close(self):
+               self._onTimeout.cancel()
+               self._callback = None
 
        def set_state(self, newState):
+               if self._state == newState:
+                       return
                oldState = self._state
-               _moduleLogger.info("Transitioning from %s to %s" % (oldState, newState))
+               _moduleLogger.info("%s Transitioning from %s to %s" % (self._name, oldState, newState))
 
                self._state = newState
-               self.reset_timers()
+               self._reset_timers(initialize=True)
 
-       def get_state(self):
+       @property
+       def state(self):
                return self._state
 
        def reset_timers(self):
@@ -94,50 +300,44 @@ class StateMachine(object):
        def request_reset_timers(self):
                return self._callback
 
-       @gobject_utils.async
-       @gtk_toolbox.log_exception(_moduleLogger)
-       def _request_reset_timers(self, *args):
-               self.reset_timers()
+       @property
+       def _strategy(self):
+               return self._strategies[self._state]
 
-       def _set_initial_period(self):
-               self._currentPeriod = self._INITIAL_ACTIVE_PERIOD / 2 # We will double it later
+       @property
+       def maxTime(self):
+               return self._maxTime
 
-       def _schedule_update(self):
-               nextTimeout = self._calculate_step(self._state, self._currentPeriod)
-               nextTimeout = int(nextTimeout)
-               if nextTimeout != self._INFINITE_PERIOD:
-                       self._timeoutId = gobject.timeout_add(nextTimeout, self._on_timeout)
-               _moduleLogger.info("Next update in %s ms" % (nextTimeout, ))
-               self._currentPeriod = nextTimeout
-
-       def _stop_update(self):
-               if self._timeoutId is None:
-                       return
-               gobject.source_remove(self._timeoutId)
-               self._timeoutId = None
+       @misc_utils.log_exception(_moduleLogger)
+       def _request_reset_timers(self, *args):
+               self._reset_timers()
 
-       def _reset_timers(self):
-               self._stop_update()
-               self._set_initial_period()
+       def _reset_timers(self, initialize=False):
+               if not self._isActive:
+                       return # not started yet
+               _moduleLogger.info("%s Resetting State Machine" % (self._name, ))
+               self._onTimeout.cancel()
+               if initialize:
+                       self._strategy.initialize_state()
+               else:
+                       self._strategy.reinitialize_state()
                self._schedule_update()
 
+       def _schedule_update(self):
+               self._strategy.increment_state()
+               nextTimeout = self._strategy.timeout
+               if nextTimeout != self.INFINITE_PERIOD and nextTimeout < self._maxTime:
+                       assert 0 < nextTimeout
+                       self._onTimeout.start(seconds=nextTimeout)
+                       _moduleLogger.info("%s Next update in %s seconds" % (self._name, nextTimeout, ))
+               else:
+                       _moduleLogger.info("%s No further updates (timeout is %s seconds)" % (self._name, nextTimeout, ))
+
+       @misc_utils.log_exception(_moduleLogger)
        def _on_timeout(self):
-               _moduleLogger.info("Update")
+               self._schedule_update()
                for item in self._updateItems:
                        try:
                                item.update(force=True)
                        except Exception:
                                _moduleLogger.exception("Update failed for %r" % item)
-               self._schedule_update()
-               return False # do not continue
-
-       @classmethod
-       def _calculate_step(cls, state, period):
-               if state == cls.STATE_ACTIVE:
-                       return min(period * 2, cls._FINAL_ACTIVE_PERIOD)
-               elif state == cls.STATE_IDLE:
-                       return cls._IDLE_PERIOD
-               elif state == cls.STATE_DND:
-                       return cls._INFINITE_PERIOD
-               else:
-                       raise RuntimeError("Unknown state: %r" % (state, ))