Re: POP3 "resume download" extension

> > > Thinking about pipelining, though, how does this sound: POP3 is normally a
> > > half-duplex-like dialog.  Suppose we allow an allowed a received command
> > > sequence (like maybe "!NEXT") to queue an interrupt of the download at
> > > the next chunk.
> >
> > If you're suggesting that servers do out-of-order command processing,
> > I don't think that's the way to go.
> >
> 
> No, I didn't really mean out-of-order command processing.  What I meant is 
> that there would be a recurring state at the end of every chunk in 
> which the server checks to see whether it has received an "interrupt" 
> command.  

I think there would be significant pushback against changes to the basic
POP request-response command structure...it would be difficult to retro-fit
existing servers to support it and once you get away from simple 
request-response it's fairly easy to introduce silly states.

(e.g.: suppose a client wants to issue several commands at once without
waiting for a response, and then later on needs to interrupt a transfer.
by the time the server gets the interrupt, it's working on a different
transfer already, and it interrupts the wrong one.) 

Keith