Re: [PATCH v2 4/5] index-pack, unpack-objects: add --not-so-strict for connectivity check

> Subject: [PATCH] clone: open a shortcut for connectivity check
>
> In order to make sure the cloned repository is good, we run "rev-list
> --objects --not --all $new_refs" on the repository. This is expensive
> on large repositories. This patch attempts to mitigate the impact in
> this special case.
>
> In the "good" clone case, we only have one pack. If all of the
> following are met, we can be sure that all objects reachable from the
> new refs exist, which is the intention of running "rev-list ...":
>
>  - all refs point to an object in the pack
>  - there are no dangling pointers in any object in the pack
>  - all objects in the pack does not point to objects outside the pack

>
> The second and third checks can be done with the help of index-pack as
> a slight modification of --strict check (which introduces a new
> condition for the shortcut: pack transfer must be used and the number
> of objects large enough to call index-pack). The first is checked in
> check_everything_connected after we get an "ok" from index-pack.
>
> "index-pack + new checks" is still faster than "index-pack + rev-list"
> currently, which is the whole point of this patch. If any of the
> conditions fails, we fall back to good old and expensive "rev-list
> ..". In that case it's even more expensive because we have to pay for
> the new checks in index-pack.
>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>