Event for logging end of aborted streaming request

Is there some event triggered when the client aborts a request to file that is streamed through workers? We would like to keep of how many bytes are delivered to the client but it seems that the thread is closed down as soon as the request is aborted?
I’m considering if we could use the ctx.event.waitUntil in combination with some sleep loop to make sure the worker stays running after the request is aborted? As it’s not very elegant if feels like a last resort… In case we would use this strategy, is there some propery on the ctx object that we can query to see if the connection to the client still is open?