Subject: Re: [PATCH v6 10/11] for-each-ref: introduce filter_refs()

From: Junio C Hamano <[email-masked]>
Date: Mon, 08 Jun 2015 11:15:20 -0700

Karthik Nayak <[email-masked]> writes:

> +/*
> + * API for filtering a set of refs. The refs are provided and iterated
> + * over using the for_each_ref_fn(). The refs are stored into and filtered
> + * based on the ref_filter_cbdata structure.
> + */
> +int filter_refs(int (for_each_ref_fn)(each_ref_fn, void *), struct ref_filter_cbdata *data)
> +{
> +	return for_each_ref_fn(ref_filter_handler, data);
> +}

I do not think it is such a good idea to allow API callers to
specify for-each-ref-fn directly.  See my message in an earlier
review.

I also think ref_filter_cbdata is an implementation detail of
filter_refs and may not have to be exposed to the API callers.
It probably is more sensible for them to pass

 - an array of refs to receive filtered results (your ref_array thing)
 - the criteria to use when filtering (your ref_filter thing)

as two separate parameters to this function, together with other
parameters that lets you (meaning the implementation of filter_refs())
to decide which for-each-ref iterator to call, e.g. do you want to
use raw iteration?  do you want to iterate only over refs/heads? etc.

In other words, the caller of this API should not have to know that
you (meaning the implementation of filter_refs()) are internally
using for_each_ref() API.