Re: [PATCH 0/4] Performance improvement & cleanup in loose ref iteration

> While investigating ref iteration performance in builtins like
> 'for-each-ref' and 'show-ref', I found two small improvement opportunities.
>
> The first patch tweaks the logic around prefix matching in
> 'cache_ref_iterator_advance' so that we correctly skip refs that do not
> actually match a given prefix. The unnecessary iteration doesn't seem to be
> causing any bugs in the ref iteration commands that I've tested, but it
> doesn't hurt to be more precise (and it helps with some other patches I'm
> working on ;) ).
>
> The next three patches update how 'loose_fill_ref_dir' determines the type
> of ref cache entry to create (directory or regular). On platforms that
> include d_type information in 'struct dirent' (as far as I can tell, all
> except NonStop & certain versions of Cygwin), this allows us to skip calling
> 'stat'. In ad-hoc testing, this improved performance of 'git for-each-ref'
> by about 20%.