Re: [PATCH v2 17/16] t3427: accelerate this test by using fast-export and fast-import

Johannes Schindelin [off-list ref] writes:

Hi Elijah,

On Wed, 4 Sep 2019, Elijah Newren wrote:

quoted

fast-export and fast-import can easily handle the simple rewrite that
was being done by filter-branch, and should be faster on systems with a
slow fork.  Measuring the overall time taken for all of t3427 (not just
the difference between filter-branch and fast-export/fast-import) shows
a speedup of about 5% on Linux and 11% on Mac.

Signed-off-by: Elijah Newren <redacted>
---
This patch is meant to be added onto the end of js/rebase-r-strategy; an
earlier version of this patch conflicted js/rebase-r-strategy so now I'm
basing on top of that series.  The speedup is also less impressive now
that there is only one filter-branch invocation being replaced instead of
a handful.  Still a nice speedup, though.

ACK!

Thanks,
Dscho

Thanks, both.  This indeed is a good update.

quoted

 t/t3427-rebase-subtree.sh | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/t/t3427-rebase-subtree.sh b/t/t3427-rebase-subtree.sh
index 39e348de16..bec48e6a1f 100755
--- a/t/t3427-rebase-subtree.sh
+++ b/t/t3427-rebase-subtree.sh

@@ -59,7 +59,10 @@ test_expect_success 'setup' '
 	test_commit files_subtree/master5 &&

 	git checkout -b to-rebase &&
-	git filter-branch --prune-empty -f --subdirectory-filter files_subtree &&
+	git fast-export --no-data HEAD -- files_subtree/ |
+		sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" |
+		git fast-import --force --quiet &&
+	git reset --hard &&
 	git commit -m "Empty commit" --allow-empty
 '

--

2.22.0.19.ga495766805