Re: [PATCH 2/2] sha1_file: fix iterating loose alternate objects

> On 2015-02-02, at 09:53, Jeff King <peff@peff.net> wrote:
> 
> I think this is probably the best fix, and is the pattern we use
> elsewhere when touching alt->base.
> 
> We _could_ further change this to have for_each_loose_file_in_objdir
> actually use alt->base as its scratch buffer, writing the object
> filenames into the end of it (i.e., what it was designed for). But:
> 
>  1. We still need a strbuf scratch-buffer for the non-alternate object
>     directory. So we'd have to push more code there to over-allocate
>     the buffer, and then for_each_loose_file_in_objdir would assume
>     we always feed it a buffer with the extra slop. That would work,
>     but I find the strbuf approach a little safer; there's not an
>     implicit over-allocation far away in the code preventing us from
>     overflowing a buffer.
> 
>  2. The reason for the existing alt->base behavior is that the
>     sha1_file code gets fed objects one at a time, and don't want to
>     pay strbuf overhead for each. With the iterator, we know we are
>     going to hit a bunch of objects, so we only have to pay the strbuf
>     overhead once for the iteration. So there's not the same
>     performance penalty, and we can stick with the strbuf if we prefer
>     it.