Haskell SendFile zero-copy - Abort the transfert

Question

Hi I want to use the following lib in Haskell for transferring files between nodes : https://hackage.haskell.org/package/sendfile-0.7.11.1/docs/Network-Socket-SendFile.html

I want to be able to abort the sendFile if the file has been transferred by another node basically...

I was thinking using the iteratee for doing it like in this example :

runIter :: IO Iter -> IO ()
runIter iter =
   do r <- iter
      case r of
        (Done _n)      -> return ()
        (Sent _n cont) -> runIter cont
        (WouldBlock _n fd cont) -> 
            do threadWaitWrite fd
               runIter cont

My question is : How can I abort this transfert ?

I was thinking doing something like this :

(Sent _n cont) -> return () or (Sent _n cont) -> error "Already downloaded (Abort)"

Basically having a way for the client to know the call has been aborted...

Nothing is explained in the lib for implementing that kind of behaviour...