Re: [gtk-vnc-devel] [PATCH 5/7] Use X window backing store for the VNC window 2008-11-24 Federico Mena Quintero <federico novell com>

["Daniel P. Berrange" <berrange redhat com>]

On Thu, Dec 18, 2008 at 10:08:25AM -0600, Federico Mena Quintero wrote:
> On Wed, 2008-12-17 at 19:51 -0600, Anthony Liguori wrote:
> 
> [backing store]
> > 
> > Is this just double buffering in GTK parlance?  If you avoid disabling 
> > double buffering, does that help?
> 
> Nope, it's different.  You can ask the X server to use backing store if
> possible --- if the server can save the contents of a window, it can
> avoid sending Expose events when the window is unobscured.  That is,
> nothing goes over the wire in the ideal case.
> 
> [This is similar to requesting "save-unders" for temporary windows, but
> it saves your actual contents, not the underlying contents.]

Ok, I see how this can make a big difference for slow X connections.
Obviously it'll have a bit of a memory overhead in the X server
to maintain the backing store. 

ACk to the patch in principle, once its has been #ifdef'd to not hardcode
the use of GTK X backend on all platforms. 

Daniel
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