Re: [PATCH v7 6/6] Reftable support for git-core

Han-Wen Nienhuys [off-list ref] writes:

So, the ref backend should manage the HEAD ref, but iteration should
not produce the HEAD ref.

Yeah, as there is a dedicated API function head_ref().

Things like ORIG_HEAD and MERGE_HEAD have always been curiosity
outside the official API, but IIRC read_ref() and friends are
prepared to read them [*1*], so the vocabulary may be unbounded [*2*].

These won't be listed in for_each_ref() iteration, either (think of
for_each_ref() as a filtered "ls -R .git/refs/" output).

Thanks.


[Footnotes]

*1* I do not offhand know if these *_HEAD pseudo-refs are written
via the refs API---it probably is the safest to arrange the ref
backends in such a way that they always go to the files backend,
even if HEAD and refs/* are managed by a backend different from the
files one.

*2* I vaguely recall that back when ref-backend infrastructure was
introduced, we had discussion on declaring that "^[A-Z_]*HEAD$"
directly under $GIT_DIR/ are these special refs (and nothing else
directly under $GIT_DIR/ is).  I do not recall what happend to the
discussion, though other folks may.

On Thu, Feb 27, 2020 at 5:23 PM Junio C Hamano [off-list ref] wrote:

Han-Wen Nienhuys [off-list ref] writes:

quoted

So, the ref backend should manage the HEAD ref, but iteration should
not produce the HEAD ref.

Yeah, as there is a dedicated API function head_ref().

Things like ORIG_HEAD and MERGE_HEAD have always been curiosity
outside the official API, but IIRC read_ref() and friends are
prepared to read them [*1*], so the vocabulary may be unbounded [*2*].

These won't be listed in for_each_ref() iteration, either (think of
for_each_ref() as a filtered "ls -R .git/refs/" output).

currently the code says

 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 {
   return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
 }

but it looks like this should do

   return do_for_each_ref(refs, "refs/", fn, 0, 0, cb_data);

instead.

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