Re: ocaml libxl bindings and KeyedUnion

[Ian Campbell <ian.campbell@citrix.com>]

On Fri, 2015-03-20 at 17:44 +0100, Olaf Hering wrote:
> +         ("dev", Struct(None, [("m", libxl_vscsi_hctl)])),
> +         ("wwn", Struct(None, [("m", string)])),
> +         ("hctl", Struct(None, [("m", libxl_vscsi_hctl)])),

> > Aside: What is the difference between dev and hctl in this context?
> 
> Its supposed to represent either "/dev/something" and "h:ct:l".

So shouldn't dev by a string then?

>  The
> result in the "p-dev" property, which is used by the backend, is the
> same.  But translating "p-dev" back into the config string for the
> scsi-list command needs some way to represent that. I'm not fully happy
> with the current way. Perhaps the code should just reuse the "p-devname"
> property to tell what was in the config file.

Perhaps the list command should just list the canonical name for the
device (i.e p-dev? a h:c:t:l tuple) and not worry about matching the
config file?

I'd even go as far as suggesting that the libxl API ought only to deal
with the canonical name and that the toolstack can parse whatever forms
it likes into that (perhaps using a helper from libxlu). That would make
the libxl interface a lot simpler, wouldn't it?

Ian.