Re: [PATCH v4 02/19] convert: add [async_]convert_to_working_tree_ca() variants

>
> From: Jeff Hostetler <jeffhost@microsoft.com>
>
> Separate the attribute gathering from the actual conversion by adding
> _ca() variants of the conversion functions. These variants receive a
> precomputed 'struct conv_attrs', not relying, thus, on a index state.

> They will be used in a future patch adding parallel checkout support,
> for two reasons:
>
> - We will already load the conversion attributes in checkout_entry(),
>   before conversion, to decide whether a path is eligible for parallel
>   checkout. Therefore, it would be wasteful to load them again later,
>   for the actual conversion.
>
> - The parallel workers will be responsible for reading, converting and
>   writing blobs to the working tree. They won't have access to the main
>   process' index state, so they cannot load the attributes. Instead,
>   they will receive the preloaded ones and call the _ca() variant of
>   the conversion functions. Furthermore, the attributes machinery is
>   optimized to handle paths in sequential order, so it's better to leave
>   it for the main process, anyway.

> @@ -1447,7 +1447,7 @@ void convert_to_git_filter_fd(const struct index_state *istate,
>         ident_to_git(dst->buf, dst->len, dst, ca.ident);
>  }
>
> -static int convert_to_working_tree_internal(const struct index_state *istate,
> +static int convert_to_working_tree_internal(const struct conv_attrs *ca,