def start(self):
if self._state == self._STARTED:
return self
self._started_at = misc.wallclock()
self._stopped_at = None
self._state = self._STARTED
return self
def elapsed(self):
if self._state == self._STOPPED:
return float(self._stopped_at - self._started_at)
elif self._state == self._STARTED:
return float(misc.wallclock() - self._started_at)
else:
raise RuntimeError("Can not get the elapsed time of an invalid"
" stopwatch")
def leftover(self):
if self._duration is None:
raise RuntimeError("Can not get the leftover time of a watch that"
" has no duration")
if self._state != self._STARTED:
raise RuntimeError("Can not get the leftover time of a stopwatch"
" that has not been started")
end_time = self._started_at + self._duration
return max(0.0, end_time - misc.wallclock())
def stop(self):
if self._state == self._STOPPED:
return self
if self._state != self._STARTED:
raise RuntimeError("Can not stop a stopwatch that has not been"
" started")
self._stopped_at = misc.wallclock()
self._state = self._STOPPED
return self
