import time
import sortedcontainers
class TimerScheduler:
def __init__(self):
self._timers_by_expire_time = sortedcontainers.SortedDict()
def now(self):
return time.monotonic()
def schedule(self, timer):
expire_time = timer.expire_time()
assert expire_time is not None
if expire_time in self._timers_by_expire_time:
self._timers_by_expire_time[expire_time].append(timer)
else:
self._timers_by_expire_time[expire_time] = [timer]
def unschedule(self, timer):
expire_time = timer.expire_time()
assert expire_time is not None
assert expire_time in self._timers_by_expire_time
timers_with_matching_expire = self._timers_by_expire_time[expire_time]
assert timer in timers_with_matching_expire
timers_with_matching_expire.remove(timer)
if timers_with_matching_expire == []:
self._timers_by_expire_time.pop(expire_time)
def expired_timers_pending(self):
if not self._timers_by_expire_time:
return False
now = self.now()
next_expire_time = self._timers_by_expire_time.peekitem(0)[0]
if next_expire_time > now:
return False
return True
def trigger_all_expired_timers(self):
# Trigger all expired timers and return time until next expire
now = self.now()
while True:
if not self._timers_by_expire_time:
return None
next_expire_time = self._timers_by_expire_time.peekitem(0)[0]
if next_expire_time > now:
return next_expire_time - now
expired_timers = self._timers_by_expire_time.popitem(0)[1]
for timer in expired_timers:
timer.trigger_expire()
def stop_all_timers(self):
while self._timers_by_expire_time:
timers = self._timers_by_expire_time.peekitem(0)[1]
for timer in timers:
timer.stop()
TIMER_SCHEDULER = TimerScheduler()
class Timer:
def __init__(self, interval, expire_function, periodic=True, start=True):
self._running = False
self._periodic = periodic
self._interval = interval
self._expire_time = None
self._expire_function = expire_function
if start:
self.start()
def __del__(self):
self.stop()
def running(self):
return self._running
def interval(self):
return self._interval
def expire_time(self):
return self._expire_time
def remaining_time_str(self):
if self._running:
secs_left = self._expire_time - TIMER_SCHEDULER.now()
return "{:06f} secs".format(secs_left)
else:
return "Stopped"
def start(self):
if self._running:
self.stop()
self._running = True
self._expire_time = TIMER_SCHEDULER.now() + self._interval
TIMER_SCHEDULER.schedule(self)
def stop(self):
if self._running:
TIMER_SCHEDULER.unschedule(self)
self._running = False
self._expire_time = None
def trigger_expire(self):
if self._expire_function is not None:
self._expire_function()
if self._periodic:
# Next expire is not now + interval but current expire_time + interval because the
# expire function may be called too late when the system is busy, in which case we
# try to catch up.
self._expire_time += self._interval
TIMER_SCHEDULER.schedule(self)
else:
self._running = False
self._expire_time = None
