diff mbox series

[v2,2/4] t3427: accelerate this test by using fast-export and fast-import

Message ID 20190828002210.8862-3-newren@gmail.com (mailing list archive)
State New, archived
Headers show
Series Warn about git-filter-branch usage and avoid it | expand

Commit Message

Elijah Newren Aug. 28, 2019, 12:22 a.m. UTC 
fast-export and fast-import can easily handle the simple rewrite that
was being done by filter-branch, and should be significantly faster on
systems with a slow fork.  Timings from before and after on two laptops
that I have access to (measured via `time ./t3427-rebase-subtree.sh`,
i.e. including everything in this test -- not just the filter-branch or
fast-export/fast-import pair):

   Linux:  4.305s -> 3.684s (~17% speedup)
   Mac:   10.128s -> 7.038s (~30% speedup)

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 t/t3427-rebase-subtree.sh | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

Comments

Eric Sunshine Aug. 28, 2019, 6 a.m. UTC | #1 
On Tue, Aug 27, 2019 at 8:22 PM Elijah Newren <newren@gmail.com> wrote:
> fast-export and fast-import can easily handle the simple rewrite that
> was being done by filter-branch, and should be significantly faster on
> systems with a slow fork.  Timings from before and after on two laptops
> that I have access to (measured via `time ./t3427-rebase-subtree.sh`,
> i.e. including everything in this test -- not just the filter-branch or
> fast-export/fast-import pair):
> [...]
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
> diff --git a/t/t3427-rebase-subtree.sh b/t/t3427-rebase-subtree.sh
> @@ -11,6 +11,12 @@ commit_message() {
> +extract_files_subtree() {

Style nit: add space before opening '('

(However, commit_message() function just above this doesn't follow
that style, so...)

> +       git fast-export --no-data HEAD -- files_subtree/ \
> +               | sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" \
> +               | git fast-import --force --quiet

This would be a bit less noisy if you ended each line with the pipe
operator, allowing you to drop the backslashes:

    git fast-export --no-data HEAD -- files_subtree/ |
        sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" |
        git fast-import --force --quiet

> +}

Not sure any of this is worth a re-roll.
diff mbox series

Patch

diff --git a/t/t3427-rebase-subtree.sh b/t/t3427-rebase-subtree.sh
index d8640522a0..943ae92226 100755
--- a/t/t3427-rebase-subtree.sh
+++ b/t/t3427-rebase-subtree.sh
@@ -11,6 +11,12 @@  commit_message() {
 	git log --pretty=format:%s -1 "$1"
 }
 
+extract_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
+}
+
 test_expect_success 'setup' '
 	test_commit README &&
 	mkdir files &&
@@ -42,7 +48,7 @@  test_expect_failure REBASE_P \
 	'Rebase -Xsubtree --preserve-merges --onto commit 4' '
 	reset_rebase &&
 	git checkout -b rebase-preserve-merges-4 master &&
-	git filter-branch --prune-empty -f --subdirectory-filter files_subtree &&
+	extract_files_subtree &&
 	git commit -m "Empty commit" --allow-empty &&
 	git rebase -Xsubtree=files_subtree --preserve-merges --onto files-master master &&
 	verbose test "$(commit_message HEAD~)" = "files_subtree/master4"
@@ -53,7 +59,7 @@  test_expect_failure REBASE_P \
 	'Rebase -Xsubtree --preserve-merges --onto commit 5' '
 	reset_rebase &&
 	git checkout -b rebase-preserve-merges-5 master &&
-	git filter-branch --prune-empty -f --subdirectory-filter files_subtree &&
+	extract_files_subtree &&
 	git commit -m "Empty commit" --allow-empty &&
 	git rebase -Xsubtree=files_subtree --preserve-merges --onto files-master master &&
 	verbose test "$(commit_message HEAD)" = "files_subtree/master5"
@@ -64,7 +70,7 @@  test_expect_failure REBASE_P \
 	'Rebase -Xsubtree --keep-empty --preserve-merges --onto commit 4' '
 	reset_rebase &&
 	git checkout -b rebase-keep-empty-4 master &&
-	git filter-branch --prune-empty -f --subdirectory-filter files_subtree &&
+	extract_files_subtree &&
 	git commit -m "Empty commit" --allow-empty &&
 	git rebase -Xsubtree=files_subtree --keep-empty --preserve-merges --onto files-master master &&
 	verbose test "$(commit_message HEAD~2)" = "files_subtree/master4"
@@ -75,7 +81,7 @@  test_expect_failure REBASE_P \
 	'Rebase -Xsubtree --keep-empty --preserve-merges --onto commit 5' '
 	reset_rebase &&
 	git checkout -b rebase-keep-empty-5 master &&
-	git filter-branch --prune-empty -f --subdirectory-filter files_subtree &&
+	extract_files_subtree &&
 	git commit -m "Empty commit" --allow-empty &&
 	git rebase -Xsubtree=files_subtree --keep-empty --preserve-merges --onto files-master master &&
 	verbose test "$(commit_message HEAD~)" = "files_subtree/master5"
@@ -86,7 +92,7 @@  test_expect_failure REBASE_P \
 	'Rebase -Xsubtree --keep-empty --preserve-merges --onto empty commit' '
 	reset_rebase &&
 	git checkout -b rebase-keep-empty-empty master &&
-	git filter-branch --prune-empty -f --subdirectory-filter files_subtree &&
+	extract_files_subtree &&
 	git commit -m "Empty commit" --allow-empty &&
 	git rebase -Xsubtree=files_subtree --keep-empty --preserve-merges --onto files-master master &&
 	verbose test "$(commit_message HEAD)" = "Empty commit"
@@ -96,7 +102,7 @@  test_expect_failure REBASE_P \
 test_expect_failure 'Rebase -Xsubtree --onto commit 4' '
 	reset_rebase &&
 	git checkout -b rebase-onto-4 master &&
-	git filter-branch --prune-empty -f --subdirectory-filter files_subtree &&
+	extract_files_subtree &&
 	git commit -m "Empty commit" --allow-empty &&
 	git rebase -Xsubtree=files_subtree --onto files-master master &&
 	verbose test "$(commit_message HEAD~2)" = "files_subtree/master4"
@@ -106,7 +112,7 @@  test_expect_failure 'Rebase -Xsubtree --onto commit 4' '
 test_expect_failure 'Rebase -Xsubtree --onto commit 5' '
 	reset_rebase &&
 	git checkout -b rebase-onto-5 master &&
-	git filter-branch --prune-empty -f --subdirectory-filter files_subtree &&
+	extract_files_subtree &&
 	git commit -m "Empty commit" --allow-empty &&
 	git rebase -Xsubtree=files_subtree --onto files-master master &&
 	verbose test "$(commit_message HEAD~)" = "files_subtree/master5"
@@ -115,7 +121,7 @@  test_expect_failure 'Rebase -Xsubtree --onto commit 5' '
 test_expect_failure 'Rebase -Xsubtree --onto empty commit' '
 	reset_rebase &&
 	git checkout -b rebase-onto-empty master &&
-	git filter-branch --prune-empty -f --subdirectory-filter files_subtree &&
+	extract_files_subtree &&
 	git commit -m "Empty commit" --allow-empty &&
 	git rebase -Xsubtree=files_subtree --onto files-master master &&
 	verbose test "$(commit_message HEAD)" = "Empty commit"