diff mbox series

[v4,3/6] revision: stop retrieving reference twice

Message ID d8e63d0943bbe3829a53561a3a1cb4f9e6963337.1628162156.git.ps@pks.im (mailing list archive)
State New, archived
Headers show
Series Speed up connectivity checks | expand

Commit Message

Patrick Steinhardt Aug. 5, 2021, 11:25 a.m. UTC 
When queueing up references for the revision walk, `handle_one_ref()`
will resolve the reference's object ID via `get_reference()` and then
queue the ID as pending object via `add_pending_oid()`. But given that
`add_pending_oid()` is only a thin wrapper around `add_pending_object()`
which fist calls `get_reference()`, we effectively resolve the reference
twice and thus duplicate some of the work.

Fix the issue by instead calling `add_pending_object()` directly, which
takes the already-resolved object as input. In a repository with lots of
refs, this translates into a near 10% speedup:

    Benchmark #1: HEAD~: rev-list --unsorted-input --objects --quiet --not --all --not $newrev
      Time (mean ± σ):      5.015 s ±  0.038 s    [User: 4.698 s, System: 0.316 s]
      Range (min … max):    4.970 s …  5.089 s    10 runs

    Benchmark #2: HEAD: rev-list --unsorted-input --objects --quiet --not --all --not $newrev
      Time (mean ± σ):      4.606 s ±  0.029 s    [User: 4.260 s, System: 0.345 s]
      Range (min … max):    4.565 s …  4.657 s    10 runs

    Summary
      'HEAD: rev-list --unsorted-input --objects --quiet --not --all --not $newrev' ran
        1.09 ± 0.01 times faster than 'HEAD~: rev-list --unsorted-input --objects --quiet --not --all --not $newrev'

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 revision.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/revision.c b/revision.c
index 793f76a509..0d99413856 100644
--- a/revision.c
+++ b/revision.c
@@ -1534,7 +1534,7 @@  static int handle_one_ref(const char *path, const struct object_id *oid,
 
 	object = get_reference(cb->all_revs, path, oid, cb->all_flags);
 	add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
-	add_pending_oid(cb->all_revs, path, oid, cb->all_flags);
+	add_pending_object(cb->all_revs, object, path);
 	return 0;
 }