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

From: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Date: Nov 17, 2008, 13:11 UTC
Message-ID: <cb7bb73a0811170511s4df6efbbl220fa89469388aca@mail.gmail.com>
In-Reply-To: <7viqqn377m.fsf@gitster.siamese.dyndns.org>

On Sun, Nov 16, 2008 at 6:34 PM, Junio C Hamano <gitster@pobox.com> wrote:

Show 17 quoted lines

> 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.

-- 
Giuseppe "Oblomov" Bilotta