[vos-d] VOS to RDF mapping

[Peter Amstutz]

On Fri, Dec 01, 2006 at 11:46:41PM -0800, Ken Taylor wrote:

> I think this is definitely needed and may even be worth getting a sketch of
> it into s5 if possible. Even something simple, like being able to
> temporarily lock an object for editing, would make programming in a
> distributed writable space a bit less headache-worthy. If you wanted to be
> especially ambitious, you could implement a round-robin system where
> multiple programs are waiting for edit-lock, and are messaged when they
> receive it (otherwise you'd have to poll for edit lock, which isn't very
> efficient).

I agree it's necessary, which is why I mentioned it.  My main concern is 
how to handle deadlock, livelock, and denial-of-service attacks.  Before 
we can do locking, we need a good lock-breaking policy.

> With all the recent talk about revision control on vobjects, I had a thought
> about this: Internally, to save space, different versions of an object (or
> different frames of an animation) would probably be stored differentially;
> only the changes from the last version/frame are actually stored. These
> "updates of the entire vobject" could consist of this kind of diff between
> versions.

Animation is a different beast from version control.  The similarity is 
in how they include a time component, but in terms of storage it would 
be very different.  Animation is also usually interpolated, which makes 
no sense for version control.

The actual messages sent out are pretty much exclusively change deltas 
and not whole entire new state data.

> Another thought was -- why not just timestamp object updates? This way, two
> updates may arrive separately but have the same timestamp, so the receiver
> knows they go together. Also, timestamping network updates is usefull for
> client-side prediction of physics and other such things, as far as I
> understand. Finally, if the receiver wanted to record an animation, it would
> have accurate time-stamping information.

Yes -- but the tricky part about timestamps is that you need to know 
what clock the time is relative to.  So this is a good idea, but it's 
part of the larger discussion of how time fits into the VOS model.

[   Peter Amstutz  ][ tetron at interreality.org ][ peter.amstutz at gdit.com ]
[Lead Programmer][Interreality Project][Virtual Reality for the Internet]
[ VOS: Next Generation Internet Communication][ http://interreality.org ]
[ http://interreality.org/~tetron ][ pgpkey:  pgpkeys.mit.edu  18C21DF7 ]

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