On Mon, Feb 19, 2024 at 04:14:16PM -0800, Junio C Hamano wrote:
> Patrick Steinhardt <ps@pks.im> writes:
> 
> > The ref and reflog iterators share much of the same underlying code to
> > iterate over the corresponding entries. This results in some weird code
> > because the reflog iterator also exposes an object ID as well as a flag
> > to the callback function. Neither of these fields do refer to the reflog
> > though -- they refer to the corresponding ref with the same name. This
> > is quite misleading. In practice at least the object ID cannot really be
> > implemented in any other way as a reflog does not have a specific object
> > ID in the first place. This is further stressed by the fact that none of
> > the callbacks except for our test helper make use of these fields.
> 
> Interesting observation.  Of course this will make the callstack
> longer by another level of indirection ...

It actually doesn't -- the old code had a `do_for_each_ref_helper()`
that did the same wrapping, so the level of indirection is exactly the
same. Over there we have it to drop the unused `struct repository`
parameter.

Patrick

> > +struct do_for_each_reflog_help {
> > +	each_reflog_fn *fn;
> > +	void *cb_data;
> > +};
> > +
> > +static int do_for_each_reflog_helper(struct repository *r UNUSED,
> > +				     const char *refname,
> > +				     const struct object_id *oid UNUSED,
> > +				     int flags,
> > +				     void *cb_data)
> > +{
> > +	struct do_for_each_reflog_help *hp = cb_data;
> > +	return hp->fn(refname, hp->cb_data);
> > +}
> 
> ... but I think it would be worth it.
> 
> > +/*
> > + * The signature for the callback function for the {refs_,}for_each_reflog()
> > + * functions below. The memory pointed to by the refname argument is only
> > + * guaranteed to be valid for the duration of a single callback invocation.
> > + */
> > +typedef int each_reflog_fn(const char *refname, void *cb_data);
> > +
> >  /*
> >   * Calls the specified function for each reflog file until it returns nonzero,
> >   * and returns the value. Reflog file order is unspecified.
> >   */
> > -int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data);
> > -int for_each_reflog(each_ref_fn fn, void *cb_data);
> > +int refs_for_each_reflog(struct ref_store *refs, each_reflog_fn fn, void *cb_data);
> > +int for_each_reflog(each_reflog_fn fn, void *cb_data);
> 
> Nice simplification.