Would anybody be interested if I added a graceful timer implementation? #459
Description
I had an idea a couple of days ago on one of my evening walks an idea for a possible New timer type and I decided not to go ahead and write a new python library just yet for it since many features would be taken straight from the Timer class object provided here. This way safer cleanup by the user could be done without task-starvation.
@types.coroutine
def _s_heartbeat():
"""
Allows a single cycle from the event loop
to pass by, it is equivilent to setting
asyncio.sleep(0) but simpler and faster
"""
yield
# Ignore the fact that I subclassed it. I'm trying to make the code smaller
# so repeated code in async_timeout doesn't have to be re-read.
class GTimer(Timeout):
"""
Graceful Timer allows things to be ran while inside of a while-loop
and is allowed to be exited gracefully
example::
async with GTimer(5) as gtimer:
while await gtimer.is_running():
...
# Somewhere after this while loop you
# could perform sensetive object cleanup.
"""
__slots__ = ("_deadline", "_loop", "_state", "_timeout_handler", "_task")
def __init__(
self, deadline: Optional[float], *, loop: asyncio.AbstractEventLoop
) -> None:
super().__init__(deadline, loop)
def _do_exit(self, exc_type: Optional[BaseException]):
# Error Silenced because GTimer is graceful
pass
def _on_timeout(self) -> None:
# Instead of killing the running task allow
# anything inside of a while loop to complete
# gracefully hence the name...
self._state = _State.TIMEOUT
# drop the reference early
self._timeout_handler = None
async def is_running(self) -> bool:
# Allow a single cycle to pass before getting the
# boolean incase user has a poorly configured while loop...
# this prevents task-starving.
await _s_heartbeat()
return self._state == _State.TIMEOUT