Subject: Re: [PATCH 6/9] pack-bitmap: expose function to iterate over bitmapped objects

From: Patrick Steinhardt <[email-masked]>
Date: Tue, 25 Feb 2025 07:59:14 +0100

On Mon, Feb 24, 2025 at 10:05:27AM -0800, Junio C Hamano wrote:
> Patrick Steinhardt <[email-masked]> writes:
> 
> > Expose a function that allows the caller to iterate over all bitmapped
> > objects of a specific type. This mechanism allows us to use the object
> > type-specific bitmaps to enumerate all objects of that type without
> > having to scan through a complete packfile.
> >
> > This functionality will be used in a subsequent commit.
> >
> > Signed-off-by: Patrick Steinhardt <[email-masked]>
> > ---
> >  builtin/pack-objects.c |  3 ++-
> >  builtin/rev-list.c     |  3 ++-
> >  pack-bitmap.c          | 65 +++++++++++++++++++++++++++++++-------------------
> >  pack-bitmap.h          | 12 +++++++++-
> >  reachable.c            |  3 ++-
> >  5 files changed, 57 insertions(+), 29 deletions(-)
> 
> After 2189649b (pack-bitmap.c: keep track of each layer's type
> bitmaps, 2024-11-19) added <type>_all bitmaps to the bitmap_index
> struct, this step would need some adjustment, I am afraid.

Hm, does it? I understand that this commit only makes the bitmaps
accessible individually per bitmapped packfile, but the bitmap indices
part of `struct bitmap_index` would continue to be the union of all of
those bitmaps. Oh, but that changes in the subsequent commits indeed,
where we start to use an `ewah_or_iterator`.

I see that Taylor's series has been sitting in an unreviewed state for a
couple months already. I can review it with the hope of moving it
forward and can then pull it in as a dependency of this series. But I'll
wait for him to chime in first to see whether anything changed about its
current state.

Patrick