From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: "Junio C Hamano" <gitster@pobox.com>,
git@vger.kernel.org, "Jakub Narebski" <jnareb@gmail.com>,
"Ted Ts'o" <tytso@mit.edu>,
"Jonathan Nieder" <jrnieder@gmail.com>,
"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
"Clemens Buchacher" <drizzd@aon.at>,
"Shawn O. Pearce" <spearce@spearce.org>
Subject: Re: [RFC/PATCHv2 6/6] limit "contains" traversals based on commit generation
Date: Wed, 13 Jul 2011 14:12:55 -0700 [thread overview]
Message-ID: <7vpqld6g14.fsf@alter.siamese.dyndns.org> (raw)
In-Reply-To: <20110713205844.GA15435@sigill.intra.peff.net> (Jeff King's message of "Wed, 13 Jul 2011 16:58:44 -0400")
Jeff King <peff@peff.net> writes:
> Or are you suggesting dropping generations entirely, and just using
> marked-up commit timestamps (or even a flag saying "this timestamp is
> bogus, don't use it for cutoffs")?
Not suggesting, but that was exactly what I was wondering. For example,
still_interesting() in revision.c says "compare timestamp and return SLOP,
not 'we are done'", and presumably that code could notice that "ah, this
commit is marked as being on a stretch that timestamp based cut-off is
unusable--keep digging". The "tag --contains" and "name-rev" would also
have similar logic (I haven't looked at them for a while though).
> But there's a big question of deciding which timestamps are bogus.
I agree that the ones that you need to dig through may not be the ones
with bogus timestamps, but either an ancestor or a descendant (I haven't
thought it through) of a commit with bogus timestamp. That is why I said
"a commit on a stretch that timestamp based cut-off is unusable".
> But I think I still like generation numbers because:
>
> 1. They're simple, complete, and unambiguous.
No question nor dispute about it.
> The only slowness for the generation slowness is the
> extra I/O on writing out the cache. But it's not very much,...
Ok.
next prev parent reply other threads:[~2011-07-13 21:13 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-13 6:47 [RFC/PATCHv2 0/6] generation numbers for faster traversals Jeff King
2011-07-13 6:57 ` [RFC/PATCHv2 1/6] decorate: allow storing values instead of pointers Jeff King
2011-07-13 17:52 ` Jonathan Nieder
2011-07-13 20:08 ` Jeff King
2011-07-14 17:34 ` Jeff King
2011-07-14 17:51 ` [PATCH 1/3] implement generic key/value map Jeff King
2011-07-14 18:52 ` Bert Wesarg
2011-07-14 18:54 ` Bert Wesarg
2011-07-14 18:55 ` Jeff King
2011-07-14 19:07 ` Bert Wesarg
2011-07-14 19:14 ` Jeff King
2011-07-14 19:18 ` Bert Wesarg
2011-07-14 17:52 ` [PATCH 2/3] fast-export: use object to uint32 map instead of "decorate" Jeff King
2011-07-15 9:40 ` Sverre Rabbelier
2011-07-15 20:00 ` Jeff King
2011-07-14 17:53 ` [PATCH 3/3] decorate: use "map" for the underlying implementation Jeff King
2011-07-14 21:06 ` [RFC/PATCHv2 1/6] decorate: allow storing values instead of pointers Junio C Hamano
2011-08-04 22:43 ` [RFC/PATCH 0/5] macro-based key/value maps Jeff King
2011-08-04 22:45 ` [PATCH 1/5] implement generic key/value map Jeff King
2011-08-04 22:46 ` [PATCH 2/5] fast-export: use object to uint32 map instead of "decorate" Jeff King
2011-08-04 22:46 ` [PATCH 3/5] decorate: use "map" for the underlying implementation Jeff King
2011-08-04 22:46 ` [PATCH 4/5] map: implement persistent maps Jeff King
2011-08-04 22:46 ` [PATCH 5/5] implement metadata cache subsystem Jeff King
2011-08-04 22:48 ` [RFC/PATCH 0/2] patch-id caching Jeff King
2011-08-04 22:49 ` [PATCH 1/2] cherry: read default config Jeff King
2011-08-04 22:49 ` [PATCH 2/2] cache patch ids on disk Jeff King
2011-08-04 22:52 ` Jeff King
2011-08-05 11:03 ` [RFC/PATCH 0/5] macro-based key/value maps Jeff King
2011-08-05 15:31 ` René Scharfe
2011-08-06 6:30 ` Jeff King
2011-07-13 7:04 ` [RFC/PATCHv2 2/6] add metadata-cache infrastructure Jeff King
2011-07-13 8:18 ` Bert Wesarg
2011-07-13 8:31 ` Jeff King
2011-07-13 8:45 ` Bert Wesarg
2011-07-13 19:18 ` Jeff King
2011-07-13 19:40 ` Junio C Hamano
2011-07-13 19:33 ` Junio C Hamano
2011-07-13 20:25 ` Jeff King
2011-07-13 7:05 ` [RFC/PATCHv2 3/6] commit: add commit_generation function Jeff King
2011-07-13 14:26 ` Eric Sunshine
2011-07-13 7:05 ` [RFC/PATCHv2 4/6] pretty: support %G to show the generation number of a commit Jeff King
2011-07-13 7:06 ` [RFC/PATCHv2 5/6] check commit generation cache validity against grafts Jeff King
2011-07-13 14:26 ` Eric Sunshine
2011-07-13 19:35 ` Jeff King
2011-07-13 7:06 ` [RFC/PATCHv2 6/6] limit "contains" traversals based on commit generation Jeff King
2011-07-13 7:23 ` Jeff King
2011-07-13 20:33 ` Junio C Hamano
2011-07-13 20:58 ` Jeff King
2011-07-13 21:12 ` Junio C Hamano [this message]
2011-07-13 21:18 ` Jeff King
2011-07-15 18:22 ` Junio C Hamano
2011-07-15 20:40 ` Jeff King
2011-07-15 21:04 ` Junio C Hamano
2011-07-15 21:14 ` Jeff King
2011-07-15 21:01 ` Generation numbers and replacement objects Jakub Narebski
2011-07-15 21:10 ` Jeff King
2011-07-16 21:10 ` Jakub Narebski
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