Re: [PATCH 07/20] migration: rename qemu_update_position to qemu_file_credit_transfer

[Dr. David Alan Gilbert]

* Daniel P. Berrangé (berrange@redhat.com) wrote:
> On Thu, Jun 09, 2022 at 01:56:00PM +0100, Peter Maydell wrote:
> > On Tue, 24 May 2022 at 12:46, Daniel P. Berrangé <berrange@redhat.com> 
> > wrote:
> > >
> > > The qemu_update_position method name gives the misleading impression
> > > that it is changing the current file offset. Most of the files are
> > > just streams, however, so there's no concept of a file offset in the
> > > general case.
> > >
> > > What this method is actually used for is to report on the number of
> > > bytes that have been transferred out of band from the main I/O methods.
> > > This new name better reflects this purpose.
> > >
> > > Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> > 
> > >  int qemu_peek_byte(QEMUFile *f, int offset);
> > >  void qemu_file_skip(QEMUFile *f, int size);
> > > -void qemu_update_position(QEMUFile *f, size_t size);
> > > +/*
> > > + * qemu_file_credit_transfer:
> > > + *
> > > + * Report on a number of bytes that have been transferred
> > > + * out of band from the main file object I/O methods.
> > > + */
> > > +void qemu_file_credit_transfer(QEMUFile *f, size_t size);
> > >  void qemu_file_reset_rate_limit(QEMUFile *f);
> > >  void qemu_file_update_transfer(QEMUFile *f, int64_t len);
> > >  void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
> > 
> > What's the difference between "credit transfer" and "update
> > transfer" ? The latter also seems to just be adding a number
> > to a count of bytes-transferred...
> 
> The other method is merely related to the rate limiting, and so
> probably ought to have 'rate_limit' included in its name too.

Bleh that's messy; I see update_transfer is used in the multifd case
as well, so makes sense for stats only and not a position in a stream
that only makes sense for a single fd.
(But now doesn't make any sense any more with these changes either)

Dave

> With regards,
> Daniel
> -- 
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-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK