[Libguestfs] [libnbd] notify API changes (was: Re: [libnbd PATCH 5/6] api: Add new nbd_aio_FOO_notify functions)
On Sat, Jun 29, 2019 at 08:28:28AM -0500, Eric Blake wrote:
As mentioned in the previous patch, there are situations where an
aio
client wants instant notification when a given command is complete,
rather than having to maintain a separate data structure to track all
in-flight commands and then iterate over that structure to learn which
commands are complete. It's also desirable when writing a server
validation program (such as for checking structured reads for
compliance) to be able to clean up the associated opaque data and have
a final chance to change the overall command status.
Introduce new nbd_aio_FOO_notify functions for each command. Rewire
the existing nbd_aio_FOO to forward to the new command. (Perhaps the
generator could reduce some of the boilerplate duplication, if a later
patch wants to refactor this).
I'm writing some code now using these new nbd_aio_<CMD>_notify
functions, and I temporarily confused myself because these are similar
to nbd_notify_read and nbd_notify_write (the functions used to signal
to the state machine that the socket is ready for reading/writing).
I wonder if we should rename something here. My suggestions are
either of the following or both:
(I) Rename nbd_notify_read / nbd_notify_write to nbd_ready_to_read /
nbd_ready_to_write.
(II) Rename nbd_aio_<CMD>_notify to nbd_aio_<CMD>_callback.
What do you think?
Rich.
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