From: "René Scharfe" <l.s.r@web.de>
To: Jeff King <peff@peff.net>
Cc: Git List <git@vger.kernel.org>,
Junio C Hamano <gitster@pobox.com>,
Jonathan Tan <jonathantanmy@google.com>
Subject: Re: [PATCH v3 2/5] fetch-pack: load tip_oids eagerly iff needed
Date: Fri, 5 Oct 2018 22:13:34 +0200 [thread overview]
Message-ID: <c75fa650-d2b4-9979-a1f2-25d75c6f447b@web.de> (raw)
In-Reply-To: <20181004220711.GA28287@sigill.intra.peff.net>
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
next prev parent reply other threads:[~2018-10-05 20:13 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-03 13:11 [PATCH v2 0/2] oidset: use khash René Scharfe
2018-10-03 13:12 ` [PATCH v2 1/2] khash: factor out kh_release_* René Scharfe
2018-10-03 13:16 ` [PATCH v2 2/2] oidset: use khash René Scharfe
2018-10-03 19:40 ` Jeff King
2018-10-04 5:56 ` René Scharfe
2018-10-04 6:48 ` Jeff King
2018-10-04 6:50 ` Jeff King
2018-10-04 15:05 ` René Scharfe
2018-10-04 15:05 ` [PATCH v3 0/5] " René Scharfe
2018-10-04 15:09 ` [PATCH v3 1/5] fetch-pack: factor out is_unmatched_ref() René Scharfe
2018-10-04 15:09 ` [PATCH v3 2/5] fetch-pack: load tip_oids eagerly iff needed René Scharfe
2018-10-04 21:38 ` Jonathan Tan
2018-10-04 22:11 ` René Scharfe
2018-10-05 20:13 ` René Scharfe
2018-10-04 22:14 ` Jeff King
2018-10-04 22:52 ` Jonathan Tan
2018-10-04 23:18 ` Jeff King
2018-10-04 22:07 ` Jeff King
2018-10-05 20:13 ` René Scharfe [this message]
2018-10-05 20:27 ` Jeff King
2018-10-05 21:22 ` René Scharfe
2018-10-05 21:47 ` Jeff King
2018-10-04 15:10 ` [PATCH v3 3/5] khash: factor out kh_release_* René Scharfe
2018-10-04 15:13 ` [PATCH v3 4/5] oidset: use khash René Scharfe
2018-10-04 15:14 ` [PATCH 5/5] oidset: uninline oidset_init() René Scharfe
2018-10-04 22:15 ` [PATCH v3 0/5] oidset: use khash Jeff King
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