Re: [PATCH v2 08/24] midx: respect 'core.multiPackIndex' when writing

On Tue, Jul 27, 2021 at 01:36:34PM -0400, Taylor Blau wrote:

quoted

But now the internal midx writing code can never call close_midx() on
that, because it does not own it to close. Can we simply drop the
close_midx() call there?

This would all make much more sense to me if write_midx_internal()
simply took a conceptually read-only midx as a parameter, and the caller
passed in the appropriate one (probably even using
prepare_multi_pack_index_one() to get it).

No, we can't drop the close_midx() call there because we must close the
MIDX file on Windows before moving a new one into place. My feeling is
we should always be working on the r->objects->multi_pack_index pointer,
and calling close_object_store() there instead of close_midx().

Does that seem like a reasonable approach to you?

Yes, though I'd have said that it is the responsibility of the caller
(who knows we are operating with r->objects->multi_pack_index) to do
that closing. But maybe it's not possible if the rename-into-place
happens at too low a level.

BTW, yet another weirdness: close_object_store() will call close_midx()
on the outermost midx struct, ignoring o->multi_pack_index->next
entirely. So that's a leak, but also means we may not be closing the
midx we're interested in (since write_midx_internal() takes an
object-dir parameter, and we could be pointing to some other
object-dir's midx).

-Peff