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

[Karthik Nayak <karthik.188@gmail.com>]

On 06/08/2015 11:45 PM, Junio C Hamano wrote:
> Karthik Nayak <karthik.188@gmail.com> 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 did read your previous message. I misunderstood some things.

>
> 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)
>

This could be done.

 >
> 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.
>

I'm a little confused about this, how exactly do you propose we go about 
doing something like this? I mean, usually the user of the API
knows what exactly they want, like in tag.c, branch.c and for-each-ref.c
But I'm not sure what you mean by "parameters that lets you (meaning the 
implementation of filter_refs()) to decide which for-each-ref iterator 
to call". A small example maybe? Thanks!

-- 
Regards,
Karthik