Re: [PATCH 1/1] diffcore: add a pickaxe option to find a specific blob

[Stefan Beller <sbeller@google.com>]

On Thu, Dec 28, 2017 at 1:33 PM, Junio C Hamano <gitster@pobox.com> wrote:
> Stefan Beller <sbeller@google.com> writes:
>
>> +static int parse_objfind_opt(struct diff_options *opt, const char *arg)
>> +{
>> +     struct object_id oid;
>> +
>> +     if (get_oid(arg, &oid))
>> +             return error("unable to resolve '%s'", arg);
>> +
>> +     if (!opt->objfind)
>> +             opt->objfind = xcalloc(1, sizeof(*opt->objfind));
>> +
>> +     opt->pickaxe = ""; /* trigger pickaxe */
>
> Hmmm.  This feels like an ugly hack to me.

Because it is.

$ git grep pickaxe diff.h
diff.h:94:      unsigned pickaxe_ignore_case:1;
diff.h:130:     const char *pickaxe;
diff.h:149:     int pickaxe_opts;
diff.h:361:"  --pickaxe-all\n" \

We could promote pickaxe_opts to be the important part
for pickaxing, currently we're using `pickaxe` in diff.c to
make a decision:

    if (options->pickaxe)
        diffcore_pickaxe(options);

So I think I'll cleanup the pickaxe_opts to be a real
unsigned flags field (such that pickaxe_ignore_case
could be part of it, too!) and put a new flag in
there in addition to DIFF_PICKAXE_KIND_{G, S}

> Do we declare that "git
> log -S''" never matches anything right now (if that is the case the
> I do not think there is any compatibility issues)?

Let's not go this route.


>
>> diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
>> index 9476bd2108..0d0c697ae7 100644
>> --- a/diffcore-pickaxe.c
>> +++ b/diffcore-pickaxe.c
>> @@ -124,13 +124,21 @@ static int pickaxe_match(struct diff_filepair *p, struct diff_options *o,
>>       mmfile_t mf1, mf2;
>>       int ret;
>>
>> -     if (!o->pickaxe[0])
>> -             return 0;
>> -
>>       /* ignore unmerged */
>>       if (!DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two))
>>               return 0;
>>
>> +     if (o->objfind) {
>> +             if ((DIFF_FILE_VALID(p->one) &&
>> +                  oidset_contains(o->objfind, &p->one->oid)) ||
>> +                 (DIFF_FILE_VALID(p->two) &&
>> +                  oidset_contains(o->objfind, &p->two->oid)))
>> +                     return 1;
>> +     }
>> +
>> +     if (!o->pickaxe[0])
>> +             return 0;
>> +
>
> Very nice.  With just one place, the code covers both cases with and
> without pickaxe-all option in effect.

and this is already fixed regarding the ugly hack, too.

Thanks,
Stefan