Re: [PATCHv3 3/4] gitweb: separate heads and remotes lists

> On Sun, Nov 16, 2008 at 6:34 PM, Junio C Hamano <gitster@pobox.com> wrote:
>> Giuseppe Bilotta <giuseppe.bilotta@gmail.com> writes:
>>> -     my @headlist = git_get_heads_list(16);
>>> +     my @headlist = git_get_heads_list(16, 'heads');
>>> +     my @remotelist = $remote_heads ? git_get_heads_list(16, 'remotes') : ();
>>
>> Wasteful to run one for-each-ref for each list.
>>
>> You earlier introduced $ref_item{'class'} so that you can differenciate
>> what you got from git_get_heads_list(); make use of it, perhaps like:
>>
>>        my @heads_list = git_get_heads_list(16, \%head_class);
>>        my @headlist = grep { $_->{'class'} eq 'head' } @heads_list;
>>        my @remotelist = grep { $_->{'class'} eq 'remote' } @heads_list;
>>
>> By the way, your [2/4] used "heads" and "remotes" as class, while your
>> [1/4] stored 'head' and 'remote' in $ref_item{'class'}.  Notice the above
>> suggestion corrects this discrepancy as well.
>
> Although I agree with the head_class idea, I would like to point out
> that doing a single git call to retrieve all refs and then selecting
> the ones we want and doing multiple git calls are not equivalent.
>
> First of all, with multiple calls we can limit the calls to retrieve
> at most 16 refs of each kind, whereas this cannot be done with a
> single call for all the refs. I'm not sure however, performance-wise,
> if it's faster to filter the first 16 refs of each after retrieving
> all of them, or doing multiple calls, especially with lots of refs.
>
> Moreover, gitweb is already doing multiple for-each-ref calls to get
> tags and heads. I guess that at this point we could go the extra mile
> and include tags in the refs management. Of course, the problem of how
> to handle the rate limiting remains.