Am 05.10.2018 um 00:07 schrieb Jeff King:
> On Thu, Oct 04, 2018 at 05:09:39PM +0200, René Scharfe wrote:
>
>> tip_oids_contain() lazily loads refs into an oidset at its first call.
>> It abuses the internal (sub)member .map.tablesize of that oidset to
>> check if it has done that already.
>>
>> Determine if the oidset needs to be populated upfront and then do that
>> instead. This duplicates a loop, but simplifies the existing one by
>> separating concerns between the two.
>
> I like this approach much better than what I showed earlier. But...
>
>> diff --git a/fetch-pack.c b/fetch-pack.c
>> index 3b317952f0..53914563b5 100644
>> --- a/fetch-pack.c
>> +++ b/fetch-pack.c
>> @@ -526,23 +526,6 @@ static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
>> oidset_insert(oids, &refs->old_oid);
>> }
>>
>> -static int tip_oids_contain(struct oidset *tip_oids,
>> - struct ref *unmatched, struct ref *newlist,
>> - const struct object_id *id)
>> -{
>> - /*
>> - * Note that this only looks at the ref lists the first time it's
>> - * called. This works out in filter_refs() because even though it may
>> - * add to "newlist" between calls, the additions will always be for
>> - * oids that are already in the set.
>> - */
>
> I don't think the subtle point this comment is making goes away. We're
> still growing the list in the loop that calls tip_oids_contain() (and
> which now calls just oidset_contains). That's OK for the reasons given
> here, but I think that would need to be moved down to this code:
>
>> + if (strict) {
>> + for (i = 0; i < nr_sought; i++) {
>> + ref = sought[i];
>> + if (!is_unmatched_ref(ref))
>> + continue;
>> +
>> + add_refs_to_oidset(&tip_oids, unmatched);
>> + add_refs_to_oidset(&tip_oids, newlist);
>> + break;
>> + }
>> + }
>
> I.e., we need to say here why it's OK to summarize newlist in the
> oidset, even though we're adding to it later.
There is already this comment:
/* Append unmatched requests to the list */
And that's enough in my eyes. The refs loop at the top splits the list
into matched ("the list") and unmatched, and the loop below said comment
adds a few more. I see no subtlety left -- what do I miss?
René
