From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Taylor Blau <me@ttaylorr.com>, Elijah Newren <newren@gmail.com>,
git@vger.kernel.org, "Eric W. Biederman" <ebiederm@gmail.com>
Subject: Re: [PATCH 7/7] builtin/merge-tree.c: implement support for `--write-pack`
Date: Mon, 09 Oct 2023 10:24:54 -0700 [thread overview]
Message-ID: <xmqqy1gb1zfd.fsf@gitster.g> (raw)
In-Reply-To: <20231008173329.GA1557002@coredump.intra.peff.net> (Jeff King's message of "Sun, 8 Oct 2023 13:33:29 -0400")
Jeff King <peff@peff.net> writes:
>> Yes, the bulk-checkin mechanism suffers from an even worse problem which
>> is the pack it creates will contain no deltas whatsoever. The contents
>> of the pack are just getting written as-is, so there's no fancy
>> delta-ficiation going on.
>
> I wonder how big a deal this would be in practice for merges.
> ...
Thanks for your experiments ;-)
The reason why bulk-checkin mechanism does not attempt deltifying
(as opposed to fast-import that attempts to deltify with the
immediately previous object and only with that single object) is
exactly the same. It was done to support the initial check-in,
which by definition lacks the delta opportunity along the time axis.
As you describe, such a delta-less pack would risk missed
deltification opportunity when running a repack (without "-f"), as
the opposite of the well known "reuse delta" heuristics, aka "this
object was stored in the base form, it is likely that the previous
pack-object tried but did not find a good delta base for it, let's
not waste time retrying that" heuristics would get in the way.
next prev parent reply other threads:[~2023-10-09 17:25 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-06 22:01 [PATCH 0/7] merge-ort: implement support for packing objects together Taylor Blau
2023-10-06 22:01 ` [PATCH 1/7] bulk-checkin: factor out `format_object_header_hash()` Taylor Blau
2023-10-06 22:01 ` [PATCH 2/7] bulk-checkin: factor out `prepare_checkpoint()` Taylor Blau
2023-10-06 22:01 ` [PATCH 3/7] bulk-checkin: factor out `truncate_checkpoint()` Taylor Blau
2023-10-06 22:01 ` [PATCH 4/7] bulk-checkin: factor our `finalize_checkpoint()` Taylor Blau
2023-10-06 22:02 ` [PATCH 5/7] bulk-checkin: introduce `index_blob_bulk_checkin_incore()` Taylor Blau
2023-10-06 22:02 ` [PATCH 6/7] bulk-checkin: introduce `index_tree_bulk_checkin_incore()` Taylor Blau
2023-10-07 3:07 ` Eric Biederman
2023-10-09 1:31 ` Taylor Blau
2023-10-06 22:02 ` [PATCH 7/7] builtin/merge-tree.c: implement support for `--write-pack` Taylor Blau
2023-10-06 22:35 ` Junio C Hamano
2023-10-06 23:02 ` Taylor Blau
2023-10-08 7:02 ` Elijah Newren
2023-10-08 16:04 ` Taylor Blau
2023-10-08 17:33 ` Jeff King
2023-10-09 1:37 ` Taylor Blau
2023-10-09 20:21 ` Jeff King
2023-10-09 17:24 ` Junio C Hamano [this message]
2023-10-09 10:54 ` Patrick Steinhardt
2023-10-09 16:08 ` Taylor Blau
2023-10-10 6:36 ` Patrick Steinhardt
2023-10-17 16:31 ` [PATCH v2 0/7] merge-ort: implement support for packing objects together Taylor Blau
2023-10-17 16:31 ` [PATCH v2 1/7] bulk-checkin: factor out `format_object_header_hash()` Taylor Blau
2023-10-17 16:31 ` [PATCH v2 2/7] bulk-checkin: factor out `prepare_checkpoint()` Taylor Blau
2023-10-17 16:31 ` [PATCH v2 3/7] bulk-checkin: factor out `truncate_checkpoint()` Taylor Blau
2023-10-17 16:31 ` [PATCH v2 4/7] bulk-checkin: factor our `finalize_checkpoint()` Taylor Blau
2023-10-17 16:31 ` [PATCH v2 5/7] bulk-checkin: introduce `index_blob_bulk_checkin_incore()` Taylor Blau
2023-10-18 2:18 ` Junio C Hamano
2023-10-18 16:34 ` Taylor Blau
2023-10-17 16:31 ` [PATCH v2 6/7] bulk-checkin: introduce `index_tree_bulk_checkin_incore()` Taylor Blau
2023-10-17 16:31 ` [PATCH v2 7/7] builtin/merge-tree.c: implement support for `--write-pack` Taylor Blau
2023-10-18 17:07 ` [PATCH v3 00/10] merge-ort: implement support for packing objects together Taylor Blau
2023-10-18 17:07 ` [PATCH v3 01/10] bulk-checkin: factor out `format_object_header_hash()` Taylor Blau
2023-10-18 17:07 ` [PATCH v3 02/10] bulk-checkin: factor out `prepare_checkpoint()` Taylor Blau
2023-10-18 17:07 ` [PATCH v3 03/10] bulk-checkin: factor out `truncate_checkpoint()` Taylor Blau
2023-10-18 17:07 ` [PATCH v3 04/10] bulk-checkin: factor out `finalize_checkpoint()` Taylor Blau
2023-10-18 17:08 ` [PATCH v3 05/10] bulk-checkin: extract abstract `bulk_checkin_source` Taylor Blau
2023-10-18 23:10 ` Junio C Hamano
2023-10-19 15:19 ` Taylor Blau
2023-10-19 17:55 ` Junio C Hamano
2023-10-18 17:08 ` [PATCH v3 06/10] bulk-checkin: implement `SOURCE_INCORE` mode for `bulk_checkin_source` Taylor Blau
2023-10-18 17:08 ` [PATCH v3 07/10] bulk-checkin: generify `stream_blob_to_pack()` for arbitrary types Taylor Blau
2023-10-18 17:08 ` [PATCH v3 08/10] bulk-checkin: introduce `index_blob_bulk_checkin_incore()` Taylor Blau
2023-10-18 23:18 ` Junio C Hamano
2023-10-19 15:30 ` Taylor Blau
2023-10-18 17:08 ` [PATCH v3 09/10] bulk-checkin: introduce `index_tree_bulk_checkin_incore()` Taylor Blau
2023-10-18 17:08 ` [PATCH v3 10/10] builtin/merge-tree.c: implement support for `--write-pack` Taylor Blau
2023-10-18 18:32 ` [PATCH v4 00/17] bloom: changed-path Bloom filters v2 (& sundries) Taylor Blau
2023-10-18 18:32 ` [PATCH v4 01/17] t/t4216-log-bloom.sh: harden `test_bloom_filters_not_used()` Taylor Blau
2023-10-18 18:32 ` [PATCH v4 02/17] revision.c: consult Bloom filters for root commits Taylor Blau
2023-10-18 18:32 ` [PATCH v4 03/17] commit-graph: ensure Bloom filters are read with consistent settings Taylor Blau
2023-10-18 18:32 ` [PATCH v4 04/17] gitformat-commit-graph: describe version 2 of BDAT Taylor Blau
2023-10-18 18:32 ` [PATCH v4 05/17] t/helper/test-read-graph.c: extract `dump_graph_info()` Taylor Blau
2023-10-18 18:32 ` [PATCH v4 06/17] bloom.h: make `load_bloom_filter_from_graph()` public Taylor Blau
2023-10-18 18:32 ` [PATCH v4 07/17] t/helper/test-read-graph: implement `bloom-filters` mode Taylor Blau
2023-10-18 18:32 ` [PATCH v4 08/17] t4216: test changed path filters with high bit paths Taylor Blau
2023-10-18 18:32 ` [PATCH v4 09/17] repo-settings: introduce commitgraph.changedPathsVersion Taylor Blau
2023-10-18 18:32 ` [PATCH v4 10/17] commit-graph: new filter ver. that fixes murmur3 Taylor Blau
2023-10-18 18:33 ` [PATCH v4 11/17] bloom: annotate filters with hash version Taylor Blau
2023-10-18 18:33 ` [PATCH v4 12/17] bloom: prepare to discard incompatible Bloom filters Taylor Blau
2023-10-18 18:33 ` [PATCH v4 13/17] commit-graph.c: unconditionally load " Taylor Blau
2023-10-18 18:33 ` [PATCH v4 14/17] commit-graph: drop unnecessary `graph_read_bloom_data_context` Taylor Blau
2023-10-18 18:33 ` [PATCH v4 15/17] object.h: fix mis-aligned flag bits table Taylor Blau
2023-10-18 18:33 ` [PATCH v4 16/17] commit-graph: reuse existing Bloom filters where possible Taylor Blau
2023-10-18 18:33 ` [PATCH v4 17/17] bloom: introduce `deinit_bloom_filters()` Taylor Blau
2023-10-18 23:26 ` [PATCH v4 00/17] bloom: changed-path Bloom filters v2 (& sundries) Junio C Hamano
2023-10-20 17:27 ` Taylor Blau
2023-10-23 20:22 ` SZEDER Gábor
2023-10-30 20:24 ` Taylor Blau
2024-01-16 22:08 ` [PATCH v5 " Taylor Blau
2024-01-16 22:09 ` [PATCH v5 01/17] t/t4216-log-bloom.sh: harden `test_bloom_filters_not_used()` Taylor Blau
2024-01-16 22:09 ` [PATCH v5 02/17] revision.c: consult Bloom filters for root commits Taylor Blau
2024-01-16 22:09 ` [PATCH v5 03/17] commit-graph: ensure Bloom filters are read with consistent settings Taylor Blau
2024-01-16 22:09 ` [PATCH v5 04/17] gitformat-commit-graph: describe version 2 of BDAT Taylor Blau
2024-01-16 22:09 ` [PATCH v5 05/17] t/helper/test-read-graph.c: extract `dump_graph_info()` Taylor Blau
2024-01-16 22:09 ` [PATCH v5 06/17] bloom.h: make `load_bloom_filter_from_graph()` public Taylor Blau
2024-01-16 22:09 ` [PATCH v5 07/17] t/helper/test-read-graph: implement `bloom-filters` mode Taylor Blau
2024-01-16 22:09 ` [PATCH v5 08/17] t4216: test changed path filters with high bit paths Taylor Blau
2024-01-16 22:09 ` [PATCH v5 09/17] repo-settings: introduce commitgraph.changedPathsVersion Taylor Blau
2024-01-29 21:26 ` SZEDER Gábor
2024-01-29 23:58 ` Taylor Blau
2024-01-16 22:09 ` [PATCH v5 10/17] commit-graph: new Bloom filter version that fixes murmur3 Taylor Blau
2024-01-16 22:09 ` [PATCH v5 11/17] bloom: annotate filters with hash version Taylor Blau
2024-01-16 22:09 ` [PATCH v5 12/17] bloom: prepare to discard incompatible Bloom filters Taylor Blau
2024-01-16 22:09 ` [PATCH v5 13/17] commit-graph.c: unconditionally load " Taylor Blau
2024-01-16 22:09 ` [PATCH v5 14/17] commit-graph: drop unnecessary `graph_read_bloom_data_context` Taylor Blau
2024-01-16 22:09 ` [PATCH v5 15/17] object.h: fix mis-aligned flag bits table Taylor Blau
2024-01-16 22:09 ` [PATCH v5 16/17] commit-graph: reuse existing Bloom filters where possible Taylor Blau
2024-01-16 22:09 ` [PATCH v5 17/17] bloom: introduce `deinit_bloom_filters()` Taylor Blau
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=xmqqy1gb1zfd.fsf@gitster.g \
--to=gitster@pobox.com \
--cc=ebiederm@gmail.com \
--cc=git@vger.kernel.org \
--cc=me@ttaylorr.com \
--cc=newren@gmail.com \
--cc=peff@peff.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.