[cups.general] Server/Client printer updates

Michael R Sweet msweet at apple.com
Mon Mar 30 09:52:19 PDT 2009


On Mar 30, 2009, at 7:10 AM, angelb wrote:
> Hello all. Just want to know if someone has already come up with  
> simillar
> suggestion or if this is worth sending to feature request.
>
> Since printer management are done on the CUPS server(s), what if  
> changes
> are logged and only those changes are sent to the polling client  
> instead of
> the entire printers in the list all the time?

Like, maybe, a subscription to printer change events?  Yes, this is  
definitely possible and is one of the things we've considered for both  
polling and automatic replication. Sadly, I haven't had the time to  
actually implement these things... :)

> Obviously, I didn't think this through thoroughly. I don't know  
> enough about
> CUPS and its internals. I just want to see if a feature like that is
> feasible, I'm sure it will require major coding, but it may worth  
> looking
> into, if not already.
>
> CUPS 1.5? :)


It certainly won't be in CUPS 1.4, but if you want to experiment you  
can play with IPP subscriptions all the way back to CUPS 1.2.  Your  
local cups-polld (maybe renamed to cups-updated? I dunno) would just  
need to grab the printer list on startup (sending updates for each),  
and then create a subscription to poll for events on a regular basis,  
sending printer updates locally as needed. Bonus points for reusing  
subscriptions across runs and doing caching...

Oh, and feel free to file a feature request for this:

     http://www.cups.org/str.php

Patches, source, etc. are welcome as well... :)

____________________________________
Michael R Sweet, Senior Printing System Engineer







More information about the cups mailing list