From: Junio C Hamano <gitster@pobox•com>
To: Jeff King <peff@peff•net>
Cc: Elijah Newren via GitGitGadget <gitgitgadget@gmail•com>,
git@vger•kernel.org, Jonathan Nieder <jrnieder@gmail•com>,
Sergey Organov <sorganov@gmail•com>,
Elijah Newren <newren@gmail•com>
Subject: Re: [PATCH 5/7] tmp-objdir: new API for creating and removing primary object dirs
Date: Tue, 28 Sep 2021 21:08:00 -0700 [thread overview]
Message-ID: <xmqqsfxof2hr.fsf@gitster.g> (raw)
In-Reply-To: <YVOiggCWAdZcxAb6@coredump.intra.peff.net> (Jeff King's message of "Tue, 28 Sep 2021 19:17:22 -0400")
Jeff King <peff@peff•net> writes:
> Side note: The pretend_object_file() approach is actually even better,
> because we know the object is fake. So it does not confuse
> write_object_file()'s "do we already have this object" freshening
> check.
>
> I suspect it could even be made faster than the tmp_objdir approach.
> From our perspective, these objects really are tempfiles. So we could
> write them as such, not worrying about things like fsyncing them,
> naming them into place, etc. We could just write them out, then mmap
> the results, and put the pointers into cached_objects (currently it
> insists on malloc-ing a copy of the input buffer, but that seems like
> an easy extension to add).
>
> In fact, I think you could get away with just _one_ tempfile per
> merge. Open up one tempfile. Write out all of the objects you want to
> "store" into it in sequence, and record the lseek() offsets before and
> after for each object. Then mmap the whole result, and stuff the
> appropriate pointers (based on arithmetic with the offsets) into the
> cached_objects list.
Cute. The remerge diff code path creates a full tree that records
the mechanical merge result. By hooking into the lowest layer of
write_object() interface, we'd serialize all objects in such a tree
in the order they are computed (bottom up from the leaf level, I'd
presume) into a single flat file ;-)
next prev parent reply other threads:[~2021-09-29 4:08 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-31 2:26 [PATCH 0/7] Add a new --remerge-diff capability to show & log Elijah Newren via GitGitGadget
2021-08-31 2:26 ` [PATCH 1/7] merge-ort: mark a few more conflict messages as omittable Elijah Newren via GitGitGadget
2021-08-31 21:06 ` Junio C Hamano
2021-09-01 0:03 ` Elijah Newren
2021-09-01 17:19 ` Junio C Hamano
2021-08-31 2:26 ` [PATCH 2/7] merge-ort: add ability to record conflict messages in a file Elijah Newren via GitGitGadget
2021-09-28 22:29 ` Jeff King
2021-09-29 6:25 ` Elijah Newren
2021-09-29 16:14 ` Junio C Hamano
2021-09-29 16:31 ` Elijah Newren
2021-09-30 7:58 ` Jeff King
2021-09-30 8:09 ` Ævar Arnfjörð Bjarmason
2021-10-01 2:07 ` Elijah Newren
2021-10-01 5:28 ` Jeff King
2021-08-31 2:26 ` [PATCH 3/7] ll-merge: add API for capturing warnings in a strbuf instead of stderr Elijah Newren via GitGitGadget
2021-09-28 22:37 ` Jeff King
2021-09-28 23:49 ` Junio C Hamano
2021-09-29 4:03 ` Elijah Newren
2021-08-31 2:26 ` [PATCH 4/7] merge-ort: capture and print ll-merge warnings in our preferred fashion Elijah Newren via GitGitGadget
2021-09-28 22:39 ` Jeff King
2021-09-30 16:53 ` Ævar Arnfjörð Bjarmason
2021-10-01 1:54 ` Elijah Newren
2021-10-01 7:23 ` Ævar Arnfjörð Bjarmason
2021-08-31 2:26 ` [PATCH 5/7] tmp-objdir: new API for creating and removing primary object dirs Elijah Newren via GitGitGadget
2021-09-28 7:55 ` Ævar Arnfjörð Bjarmason
2021-09-29 4:22 ` Elijah Newren
2021-09-30 7:41 ` Jeff King
2021-09-30 14:17 ` Ævar Arnfjörð Bjarmason
2021-10-01 3:55 ` Elijah Newren
2021-09-28 23:17 ` Jeff King
2021-09-29 4:08 ` Junio C Hamano [this message]
2021-09-30 7:33 ` Jeff King
2021-09-30 13:16 ` Ævar Arnfjörð Bjarmason
2021-09-30 21:00 ` Jeff King
2021-10-01 3:11 ` Elijah Newren
2021-10-01 7:30 ` Ævar Arnfjörð Bjarmason
2021-10-01 8:03 ` Elijah Newren
2021-10-01 4:26 ` Elijah Newren
2021-10-01 5:27 ` Jeff King
2021-10-01 7:43 ` Ævar Arnfjörð Bjarmason
2021-09-29 5:05 ` Elijah Newren
2021-09-30 7:26 ` Jeff King
2021-09-30 7:46 ` Jeff King
2021-09-30 20:06 ` Junio C Hamano
2021-10-01 3:59 ` Elijah Newren
2021-10-01 16:36 ` Junio C Hamano
2021-10-01 2:31 ` Elijah Newren
2021-10-01 5:21 ` Jeff King
2021-09-30 19:25 ` Neeraj Singh
2021-09-30 20:19 ` Junio C Hamano
2021-09-30 20:00 ` Junio C Hamano
2021-10-01 2:23 ` Elijah Newren
2021-08-31 2:26 ` [PATCH 6/7] show, log: provide a --remerge-diff capability Elijah Newren via GitGitGadget
2021-08-31 9:19 ` Sergey Organov
2021-09-28 8:01 ` Ævar Arnfjörð Bjarmason
2021-09-29 4:00 ` Elijah Newren
2021-08-31 2:26 ` [PATCH 7/7] doc/diff-options: explain the new --remerge-diff option Elijah Newren via GitGitGadget
2021-08-31 11:05 ` [PATCH 0/7] Add a new --remerge-diff capability to show & log Bagas Sanjaya
2021-08-31 16:16 ` Elijah Newren
2021-08-31 20:03 ` Junio C Hamano
2021-08-31 20:23 ` Elijah Newren
2021-09-01 21:07 ` Junio C Hamano
2021-09-01 21:42 ` Elijah Newren
2021-09-01 21:55 ` Junio C Hamano
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