From: Junio C Hamano <gitster@pobox.com>
To: Calvin Wan <calvinwan@google.com>
Cc: git@vger.kernel.org, emilyshaffer@google.com
Subject: Re: [PATCH 3/4] diff-lib: refactor functions
Date: Fri, 23 Sep 2022 13:36:20 -0700 [thread overview]
Message-ID: <xmqqleq9u8u3.fsf@gitster.g> (raw)
In-Reply-To: <20220922232947.631309-4-calvinwan@google.com> (Calvin Wan's message of "Thu, 22 Sep 2022 23:29:46 +0000")
Calvin Wan <calvinwan@google.com> writes:
> Flatten out the if statements in match_stat_with_submodule so the
> logic is more readable and easier for future patches to add to.
>
> Move code that updates relevant variables from the end of
> run_diff_files to finish_run_diff_files. A future patch will utilize
> said function.
>
> Signed-off-by: Calvin Wan <calvinwan@google.com>
> ---
> diff-lib.c | 71 ++++++++++++++++++++++++++++++++----------------------
> 1 file changed, 42 insertions(+), 29 deletions(-)
>
> diff --git a/diff-lib.c b/diff-lib.c
> index 7eb66a417a..2e148b79e6 100644
> --- a/diff-lib.c
> +++ b/diff-lib.c
> @@ -73,21 +73,50 @@ static int match_stat_with_submodule(struct diff_options *diffopt,
> unsigned *dirty_submodule)
> {
> int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
> - if (S_ISGITLINK(ce->ce_mode)) {
> - struct diff_flags orig_flags = diffopt->flags;
> - if (!diffopt->flags.override_submodule_config)
> - set_diffopt_flags_from_submodule_config(diffopt, ce->name);
> - if (diffopt->flags.ignore_submodules)
> - changed = 0;
> - else if (!diffopt->flags.ignore_dirty_submodules &&
> - (!changed || diffopt->flags.dirty_submodules))
> - *dirty_submodule = is_submodule_modified(ce->name,
> - diffopt->flags.ignore_untracked_in_submodules);
> - diffopt->flags = orig_flags;
> + struct diff_flags orig_flags = diffopt->flags;
> + if (!S_ISGITLINK(ce->ce_mode))
> + goto cleanup;
> + if (!diffopt->flags.override_submodule_config)
> + set_diffopt_flags_from_submodule_config(diffopt, ce->name);
> + if (diffopt->flags.ignore_submodules) {
> + changed = 0;
> + goto cleanup;
> }
> + if (!diffopt->flags.ignore_dirty_submodules &&
> + (!changed || diffopt->flags.dirty_submodules))
> + *dirty_submodule = is_submodule_modified(ce->name,
> + diffopt->flags.ignore_untracked_in_submodules);
> +cleanup:
> + diffopt->flags = orig_flags;
> return changed;
> }
Unlike the original, this always makes two needless structure
assignments for anything that is not a submodule.
Can we fix that regression before moving forward?
Even when ce_mode is a gitlink, if .ignore_submodules bit is set,
the two structure assignments between diffopt->flags and orig_flags
become necessary, so the original was already doing extra copies but
we do not have to make it worse.
> +static void finish_run_diff_files(struct rev_info *revs,
> + struct cache_entry *ce,
> + struct index_state *istate,
> + int changed, int dirty_submodule,
> + unsigned int newmode)
> +{
> + unsigned int oldmode;
> + const struct object_id *old_oid, *new_oid;
> +
> + if (!changed && !dirty_submodule) {
> + ce_mark_uptodate(ce);
> + if (!S_ISGITLINK(ce->ce_mode))
> + mark_fsmonitor_valid(istate, ce);
> + if (!revs->diffopt.flags.find_copies_harder)
> + return;
> + }
> + oldmode = ce->ce_mode;
> + old_oid = &ce->oid;
> + new_oid = changed ? null_oid() : &ce->oid;
> + diff_change(&revs->diffopt, oldmode, newmode,
> + old_oid, new_oid,
> + !is_null_oid(old_oid),
> + !is_null_oid(new_oid),
> + ce->name, 0, dirty_submodule);
> +}
Strange indentation. It is unclear why this bottom 1/3 of the loop
body of run_diff_files() need to be a separate helper function,
while the top 2/3 does not. The resulting loop (below) becomes very
hard to follow because the reader cannot tell when diff_change() is
called and when it is not.
Overall, I see this change detrimental to diff-lib API at this step
in the series. Later steps may show something more rewarding than
the downsides we see here, hopefully.
next prev parent reply other threads:[~2022-09-23 20:43 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-22 23:29 [PATCH 0/4] submodule: parallelize status Calvin Wan
2022-09-22 23:29 ` [PATCH 1/4] run-command: add pipe_output to run_processes_parallel Calvin Wan
2022-09-23 7:52 ` Ævar Arnfjörð Bjarmason
2022-09-26 16:59 ` Calvin Wan
2022-09-27 10:52 ` Ævar Arnfjörð Bjarmason
2022-09-23 18:58 ` Junio C Hamano
2022-09-26 17:31 ` Calvin Wan
2022-09-27 4:45 ` Junio C Hamano
2022-09-27 18:10 ` Calvin Wan
2022-09-27 21:40 ` Junio C Hamano
2022-09-27 9:05 ` Ævar Arnfjörð Bjarmason
2022-09-27 17:55 ` Calvin Wan
2022-09-27 19:34 ` Ævar Arnfjörð Bjarmason
2022-09-27 20:45 ` Calvin Wan
2022-09-28 5:40 ` Ævar Arnfjörð Bjarmason
2022-09-29 20:52 ` Calvin Wan
2022-09-22 23:29 ` [PATCH 2/4] submodule: move status parsing into function Calvin Wan
2022-09-22 23:29 ` [PATCH 3/4] diff-lib: refactor functions Calvin Wan
2022-09-23 20:36 ` Junio C Hamano [this message]
2022-09-26 17:35 ` Calvin Wan
2022-09-22 23:29 ` [PATCH 4/4] diff-lib: parallelize run_diff_files for submodules Calvin Wan
2022-09-23 8:06 ` Ævar Arnfjörð Bjarmason
2022-09-24 20:17 ` Junio C Hamano
2022-09-26 17:50 ` Calvin Wan
2022-09-23 21:44 ` Junio C Hamano
2022-09-26 19:12 ` Calvin Wan
2022-09-25 13:59 ` Phillip Wood
2022-09-26 17:11 ` Junio C Hamano
2022-09-26 19:22 ` Calvin Wan
2022-09-27 18:40 ` Emily Shaffer
2022-09-23 22:56 ` [PATCH 0/4] submodule: parallelize status Junio C Hamano
2022-09-26 16:33 ` Calvin Wan
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
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=xmqqleq9u8u3.fsf@gitster.g \
--to=gitster@pobox.com \
--cc=calvinwan@google.com \
--cc=emilyshaffer@google.com \
--cc=git@vger.kernel.org \
/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.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).