[CRIU] [PATCH 3/4] unix: add ability to set callbacks for external sockets

[Cyrill Gorcunov]

On Mon, Dec 02, 2013 at 10:21:05AM +0400, Andrew Vagin wrote:
> On Mon, Dec 02, 2013 at 10:15:04AM +0400, Cyrill Gorcunov wrote:
> > On Mon, Dec 02, 2013 at 08:47:11AM +0400, Andrew Vagin wrote:
> > > 
> > > > 
> > > > Data exchange with libraries
> > > > ============================
> > > > 
> > > > I think we might pass protobuf objects to libraries because it's extendable
> > > > so if one day you need to pass more insformation to library you simply update
> > > > protobuf file.
> > > 
> > > Pavel has suggested to pass structure with size. It's extendable too.
> > 
> > Not that convenient as protobuf.
> 
> Could you enumirate benifits from protobuf?
> 
> * easy to understand which fields are here
> * default values for optional fields
> * anything else?

They key moment is autogeneration for optional fields. Say library is compiled
with some new protobuf but get packet from criu with older version. Calculating
which fields are accessible would be pain in the ass,