Re: [Qemu-devel] [PATCH RFC v3 30/32] qapi: New QMP command query-schema for QMP schema introspection

[Michael Roth]

Quoting Eric Blake (2015-09-03 09:31:01)
> On 09/03/2015 03:26 AM, Markus Armbruster wrote:
> >>
> >> I think we need to be careful that these descriptions are not
> >> interpreted by clients as an alternative to the more-specific
> >> constraints in the QAPI schema though. 'query-schema' seems
> >> a bit misleading in that regard, it appears to be more like
> >> 'query-schema-encoding' in function. But not sure it's worth
> >> renaming or anything so long as the documentation is clear.
> > 
> > You have a point: "schema" can mean two related, yet different things.
> > There's the QAPI schema, and there's the QMP (the wire protocol) schema.
> > QMP introspection is about the latter, not the former.
> > 
> > If we want to avoid the ambiguity, we could call the command
> > query-qmp-schema or something.
> > 
> > Renaming query-schema now might confuse people coming from my KVM Forum
> > talk slightly, but if we can agree on a better name, let's do it.
> 
> I'm okay if you want to use 'query-qmp-schema'; it's a bit longer, but
> more precise, and doesn't cause too much grief to change the name at
> this point in the game.

I'm also okay with this. It avoids confusion down that road if we
ever introduced, say, a query-ber-schema or something.

I have some minor reservations: I think query-qmp-schema-mapping or
query-qmp-schema-encoding, i.e. "give me information on how the
[QAPI] schema maps to the QMP wire protocol", is more correct.
query-qmp-schema reads like "give me the complete schema for the
QMP wire protocol", which makes it more tempting to treat the
result as a complete schema, rather than a component of what's
defined by the QAPI schema.

But in all likelihood trying to cram all that information into the
command name would probably just be confusing to most, so a simpler
name with clear documentation seems reasonable.

> 
> -- 
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>