Re: [PATCH 03/10] sha1-array: provide oid_array_remove_if

>
> On 9 August 2018 at 00:17, Stefan Beller <sbeller@google.com> wrote:
> > +int oid_array_remove_if(struct oid_array *array,
> > +                       for_each_oid_fn fn,
> > +                       void *data)
> > +{
> > +       int i, j;
> > +       char *to_remove = xcalloc(array->nr, sizeof(char));
>
> Do you really need this scratch space?

>
> > +       /* No oid_array_sort() here! See the api-oid-array.txt docs! */
> > +
> > +       for (i = 0; i < array->nr; i++) {
> > +               int ret = fn(array->oid + i, data);
> > +               if (ret)
> > +                       to_remove[i] = 1;
> > +       }
> > +
> > +       i = 0, j = 0;
> > +       while (i < array->nr && j < array->nr) {
> > +               while (i < array->nr && !to_remove[i])
> > +                       i++;
> > +               /* i at first marked for deletion or out */
> > +               if (j < i)
> > +                       j = i;
> > +               while (j < array->nr && to_remove[j])
> > +                       j++;
> > +               /* j > i; j at first valid after first deletion range or out */
> > +               if (i < array->nr && j < array->nr)
> > +                       oidcpy(&array->oid[i], &array->oid[j]);
> > +               else if (i >= array->nr)
> > +                       assert(j >= array->nr);
> > +                       /* no pruning happened, keep original array->nr */
> > +               else if (j >= array->nr)
> > +                       array->nr = i;
> > +       }
> > +
> > +       free(to_remove);
> > +
> > +       return 0;
> > +}
>
> I can't entirely follow this index-fiddling, but then I haven't had my
> morning coffee yet, so please forgive me if this is nonsense. Would it
> suffice to let i point out where to place items (starting at the first
> item not to keep) and j where to take them from (i.e., the items to
> keep, after the initial run)?

> > +int oid_array_remove_if(struct oid_array *array,
> > +                       for_each_oid_fn fn,
> > +                       void *data);
>
> Maybe some documentation here, but this seems to be following suit. ;-)