diff options
| -rw-r--r-- | state_tracker.py | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/state_tracker.py b/state_tracker.py index 4f77ff4..9ce61e3 100644 --- a/state_tracker.py +++ b/state_tracker.py @@ -20,8 +20,8 @@ class StateTracker(ABC): invoked via the heartbeat() method. This method, in turn, invokes update() with update_ids according to a schedule / periodicity provided to the c'tor. - """ + """ def __init__(self, update_ids_to_update_secs: Dict[str, float]) -> None: """The update_ids_to_update_secs dict parameter describes one or more update types (unique update_ids) and the periodicity(ies), in @@ -30,6 +30,7 @@ class StateTracker(ABC): Note that, when more than one update is overdue, they will be invoked in order by their update_ids so care in choosing these identifiers may be in order. + """ self.update_ids_to_update_secs = update_ids_to_update_secs self.last_reminder_ts: Dict[str, Optional[datetime.datetime]] = {} @@ -49,6 +50,7 @@ class StateTracker(ABC): The now param is the approximate current timestamp and the last_invocation param is the last time you were invoked (or None on the first invocation) + """ pass @@ -64,6 +66,7 @@ class StateTracker(ABC): Setting force_all_updates_to_run will invoke all updates (ordered by update_id) immediately ignoring whether or not they are due. + """ self.now = datetime.datetime.now(tz=pytz.timezone("US/Pacific")) for update_id in sorted(self.last_reminder_ts.keys()): @@ -101,13 +104,15 @@ class AutomaticStateTracker(StateTracker): """Just like HeartbeatCurrentState but you don't need to pump the heartbeat; it runs on a background thread. Call .shutdown() to terminate the updates. - """ + """ @background_thread def pace_maker(self, should_terminate) -> None: """Entry point for a background thread to own calling heartbeat() at regular intervals so that the main thread doesn't need to do - so.""" + so. + + """ while True: if should_terminate.is_set(): logger.debug('pace_maker noticed event; shutting down') @@ -138,6 +143,7 @@ class AutomaticStateTracker(StateTracker): def shutdown(self): """Terminates the background thread and waits for it to tear down. This may block for as long as self.sleep_delay. + """ logger.debug( 'Setting shutdown event and waiting for background thread.' @@ -148,7 +154,26 @@ class AutomaticStateTracker(StateTracker): class WaitableAutomaticStateTracker(AutomaticStateTracker): + """This is an AutomaticStateTracker that exposes a wait method which + will block the calling thread until the state changes with an + optional timeout. The caller should check the return value of + wait; it will be true if something changed and false if the wait + simply timed out. If the return value is true, the instance + should be reset() before wait is called again. + Example usage: + + detector = waitable_presence.WaitableAutomaticStateSubclass() + while True: + changed = detector.wait(timeout=60 * 5) + if changed: + detector.reset() + # Figure out what changed and react + else: + # Just a timeout; no need to reset. Maybe do something + # else before looping up into wait again. + + """ def __init__( self, update_ids_to_update_secs: Dict[str, float], |