Re: [Libguestfs] [libnbd PATCH 5/6] api: Add new nbd_aio_FOO_notify functions
On 6/29/19 12:28 PM, Richard W.M. Jones wrote:
Obvious change given the previous patch, so ACK.
I do wonder if we should make the notify parameter mandatory (and
therefore avoid the duplicate functions).
Maybe. I've already posted the patch for nbdkit to use the notify
parameter. But for other language bindings, the version without a notify
parameter may still be easier to use.
Another trick you might do if feeling really keen is to
programmatically generate the notify variants of commands, something
like this:
let make_notify_variant_of_call ({ args; longdesc } as call) =
let args = List.rev args in
let flags, args = List.hd args, List.tl args in
assert (flags = Flags "flags");
let args = flags :: CallbackPersist ("notify", [ etc ]) :: args in
It's a little trickier - the nbd_aio_pread_structured and
nbd_aio_block_status already have an opaque parameter, but the other
calls need to add an opaque.
let args = List.rev args in
let longdesc = longdesc ^ "\nThe C<notify> callback blah blah ..." in
{ call with args; longdesc }
let aio_pwrite_call = {
default_call with
args = [ BytesPersistIn ("buf", "count"); UInt64
"offset"; Flags "flags" ]; ]
(* etc copy the definition of aio_pwrite *)
}
let aio_pwrite_notify_call = make_notify_variant_of_call aio_pwrite_call
let handle_calls = [
...
"aio_pwrite", aio_pwrite_call;
"aio_pwrite_notify", aio_pwrite_notify_call;
...
]
I may still play with the idea of better auto-generation of things, but
it's orthogonal enough to not hold up this patch going in.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
Attachments:
- signature.asc (application/pgp-signature — 488 bytes)