dynamic containers issue

["Zeeshan Ali (Khattak)" <zeenix gmail com>]

Hi everyone,
   In the D-Bus MediaServer spec that rygel-grilo implements, I made
the 'ChildCount' property of MediaContainer1 optional based on the
fact that this number is not always known in case of online sources in
grilo (e.g youtube) as the containers are dynamic (i-e their contents
change very frequently). This poses two issues:

1. UPnP specific issue: UPnP does not take into account such
containers and whenever each container changes, it must signal that
and the clients are supposed to update their views (if any) to the
container. Because of this it is mandatory to provide the correct
value for this property if/when a client asks for it.

2. Generic issue: If the containers are so dynamic, how is the client
(e.g totem) going to do incremental browsing? The current browsing API
that we have agreed on, requires the container's children to remain
not only the same but also in the same order unless the changes are
explicitly signaled.

  While #1 could either be worked-around in Rygel or rygel-grilo
(latter would be more efficient), the only easy/simple solution to #2
I see is for either rygel-grilo or grilo to simulate static containers
by keeping a local cached list of children of such dynamic containers.
You could have a timeout on this cache to keep it not completely
static but each time the cache is updated, you signal the client about
the container update (we have a signal for that). This solution will
also solve #1 above.

  What do you guys think?

-- 
Regards,

Zeeshan Ali (Khattak)
FSF member#5124