Re: [PATCH v2 3/3] index-pack: eliminate unlimited recursion in get_delta_base()
2012/1/10 Junio C Hamano <gitster@pobox.com>:
Show 13 quoted lines
> In parse_pack_objects(), we have two passes. The first pass scans to
> enumerate the objects that appear in the pack and sift them into base and
> delta objects, and the second one starts from a base object, resolves its
> immediate children with find_unresolved_daltas(), but that function recurses
> many times, bound only by the number of objects in the pack, which is the
> issue you are trying to address with this series.
>
> I wonder if a cleaner approach is to change the loop in the second pass in
> such a way that (1) the function it calls resolves _only_ the immediate
> children of the object we know its final shape (either because the object
> was recorded in the deflated form in the pack, or we have already resolved
> it in earlier iteration), and (2) the loop goes over the objects[] array
> not just once, but until we stopped making progress.
So basically:
- remove the recursion code from get_base_data()
- update find_unresolved_deltas() to mark resolved objects handled
- put find_unresolve_deltas() call into a loop to go through all
unhandled objects
correct? Yeah I think it's simpler than current code.
Show 5 quoted lines
> It would require us to be able to tell, by looking at objects[i], if the
> object itself has already been handled (perhaps you can look at its
> idx.sha1 field for this purpose) and if we have already handled its
> immediate delta children (you may need to add a bit to struct object_entry
> for this).
--
Duy
Nguyen Thai Ngoc Duy <pclouds@gmail.com>