From a7004abd0b17c2f2460f0fb318f49a75aab0785f Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Wed, 20 Nov 2024 08:51:36 +0100 Subject: [PATCH] refs: don't normalize log messages with `REF_SKIP_CREATE_REFLOG` MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When the `REF_SKIP_CREATE_REFLOG` flag is set we skip the creation of the reflog entry, but we still normalize the reflog message when we queue the update. This is a waste of resources as the normalized message will never get used in the first place. Fix this issue by skipping the normalization in case the flag is set. This leads to a surprisingly large speedup when migrating from the "files" to the "reftable" backend: Benchmark 1: migrate files:reftable (refcount = 1000000, revision = HEAD~) Time (mean ± σ): 878.5 ms ± 14.9 ms [User: 726.5 ms, System: 139.2 ms] Range (min … max): 858.4 ms … 941.3 ms 50 runs Benchmark 2: migrate files:reftable (refcount = 1000000, revision = HEAD) Time (mean ± σ): 831.1 ms ± 10.5 ms [User: 694.1 ms, System: 126.3 ms] Range (min … max): 812.4 ms … 851.4 ms 50 runs Summary migrate files:reftable (refcount = 1000000, revision = HEAD) ran 1.06 ± 0.02 times faster than migrate files:reftable (refcount = 1000000, revision = HEAD~) And an ever larger speedup when migrating the other way round: Benchmark 1: migrate reftable:files (refcount = 1000000, revision = HEAD~) Time (mean ± σ): 923.6 ms ± 11.6 ms [User: 705.5 ms, System: 208.1 ms] Range (min … max): 905.3 ms … 946.5 ms 50 runs Benchmark 2: migrate reftable:files (refcount = 1000000, revision = HEAD) Time (mean ± σ): 818.5 ms ± 9.0 ms [User: 627.6 ms, System: 180.6 ms] Range (min … max): 802.2 ms … 842.9 ms 50 runs Summary migrate reftable:files (refcount = 1000000, revision = HEAD) ran 1.13 ± 0.02 times faster than migrate reftable:files (refcount = 1000000, revision = HEAD~) Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- refs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/refs.c b/refs.c index d690eb19b3..65eea3eb77 100644 --- a/refs.c +++ b/refs.c @@ -1188,8 +1188,9 @@ struct ref_update *ref_transaction_add_update( oidcpy(&update->new_oid, new_oid); if ((flags & REF_HAVE_OLD) && old_oid) oidcpy(&update->old_oid, old_oid); + if (!(flags & REF_SKIP_CREATE_REFLOG)) + update->msg = normalize_reflog_message(msg); - update->msg = normalize_reflog_message(msg); return update; } -- 2.47.3