[PATCH 8/8] receive-pack: check connectivity via quarantined objects
- From
Patrick Steinhardt <ps@pks.im>
- Date
- May 19, 2021, 19:13 UTC
- Message-ID
- <010974639c66c8f15d4dc9e4feb69eed92b52d13.1621451532.git.ps@pks.im>
- In-Reply-To
- <cover.1621451532.git.ps@pks.im>
Convert git-receive-pack(1) to use the new connectivity check which uses the quarantine directory to enumerate new objects instead of using references. This change significantly decreases the time required to accept reference updates due to the fact that we don't need to do a graph walk anymore. The following measurements have been executed on linux.git:
Test v2.32.0-rc0 HEAD -------------------------------------------------------------------------------------------- 5400.3: receive-pack clone create 1.27(1.11+0.16) 0.02(0.01+0.01) -98.4% 5400.5: receive-pack clone update 1.27(1.13+0.13) 0.02(0.02+0.00) -98.4% 5400.7: receive-pack clone reset 0.13(0.11+0.02) 0.02(0.01+0.01) -84.6% 5400.9: receive-pack clone delete 0.02(0.01+0.01) 0.03(0.02+0.01) +50.0% 5400.11: receive-pack extrarefs create 33.01(18.80+14.43) 9.00(4.30+4.65) -72.7% 5400.13: receive-pack extrarefs update 33.13(18.85+14.50) 9.01(4.28+4.67) -72.8% 5400.15: receive-pack extrarefs reset 32.90(18.82+14.32) 9.04(4.26+4.77) -72.5% 5400.17: receive-pack extrarefs delete 9.13(4.35+4.77) 8.94(4.29+4.64) -2.1% 5400.19: receive-pack empty create 223.35(640.63+127.74) 227.55(651.75+130.94) +1.9%
Interestingly enough, the normal "clone" repository shows a more extreme improvement compared to the "extrarefs" repository, which has one reference per commit. While I haven't yet dived into the root cause, I expect that there is another location besides the connectivity check which does scale with the number of references.
Notably, the connectivity check when pushing into an empty repository shows comparable performance with the previous implementation. This is because in both cases we're actually performing a complete graph walk to determine whether there are any unreachable commits.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- builtin/receive-pack.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c index b9263cec15..23087acad0 100644 --- a/builtin/receive-pack.c +++ b/builtin/receive-pack.c @@ -1937,8 +1937,12 @@ static void execute_commands(struct command *commands, * first place. As a result, we do not set up a quarantine environment * because we know no new objects will be received. And that in turn * means that we can skip connectivity checks here. + * + * Using the quarantine directory to determine connectivity may not + * work with shallow clones, so let's let's play it safe for now and + * fall back to the old connectivity check. */ - if (tmp_objdir) { + if (tmp_objdir && (si->nr_ours || si->nr_theirs)) { struct check_connected_options opt = CHECK_CONNECTED_INIT; struct async muxer; int err_fd = 0; @@ -1960,6 +1964,10 @@ static void execute_commands(struct command *commands, if (use_sideband) finish_async(&muxer); + } else if (tmp_objdir) { + if (check_connected_quarantine(the_repository, tmp_objdir, + iterate_receive_command_list, &data)) + set_connectivity_errors(commands, si); } reject_updates_to_hidden(commands);
-- 2.31.1