Re: [RFC-PATCHv6 4/4] pathspec: allow querying for attributes

From: Stefan Beller <sbeller@google.com>
Date: May 17, 2016, 19:23 UTC
Message-ID: <CAGZ79kZ-xf167LiO+zY+B8BTYd-9h7u=dgpL=4tsEJDPgwq8CA@mail.gmail.com>
In-Reply-To: <xmqqvb2dxomo.fsf@gitster.mtv.corp.google.com>

On Mon, May 16, 2016 at 10:03 PM, Junio C Hamano <gitster@pobox.com> wrote:

Show 22 quoted lines

> When matching (i.e. the match_attrs() function), you would instead
> do
>
>         path = xmemdupz(name, namelen);
>         git_check_attr(path, item->attr_check);
>
> to grab values for only attributes that matter to you, instead of
> calling git_all_attrs() [*2*].
>
> After git_check_attr() returns, item->attr_check.check[0].attr would
> be git_attr("VAR1") and item->attr_check.check[0].value would be
> whatever setting the path has for the VAR1 attribute.  You can use
> your match_mode logic to compare it with the values .attr_match
> expects.
>
> You do not necessarily have to have the same number of elements in
> .attr_match and .attr_check.check by the way.  .attr_match might say
>
>         VAR1=VAL2 !VAR1 -VAR1
>
> which may be always false if these are ANDed together, but in order
> to evaluate it, you need only one git_attr_check_elem for VAR1.

So for the matching we would need to get the order right, i.e.

    const char *inspect_name = git_attr_name(item.attr_match[i].attr);
    for (j=0; j <  p.attr_check.check_nr; j++) {
        const char *cur_name = git_attr_name(p.attr_check.check[j].attr);
        if (!strcmp(inspect_name, cur_name))
            break;
    // now compare .attr_match[i] with attr_check.check[j]

This doesn't look cheap to me? Am I holding it wrong again?