On 8/26/2019 7:52 PM, Elijah Newren 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):
>
> Linux: 4.305s -> 3.684s (~17% speedup)
> Mac: 10.128s -> 7.038s (~30% speedup)
Again, impressive speedup!
> Signed-off-by: Elijah Newren <new...@gmail.com>
> ---
> t/t3427-rebase-subtree.sh | 32 ++++++++++++++++++++++++--------
> 1 file changed, 24 insertions(+), 8 deletions(-)
>
> diff --git a/t/t3427-rebase-subtree.sh b/t/t3427-rebase-subtree.sh
> index d8640522a0..d05fcce5dc 100755
> --- a/t/t3427-rebase-subtree.sh
> +++ b/t/t3427-rebase-subtree.sh
> @@ -42,7 +42,9 @@ 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
> &&
> + git fast-export --no-data HEAD -- files_subtree/ \
> + | sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" \
> + | git fast-import --force --quiet &&
> git commit -m "Empty commit" --allow-empty &&
There's a lot of repetition in these changes. Is this a good time
to introduce a helper method? This trio of commands happens to be
difficult to parse, so I'd rather do it just once.
> git rebase -Xsubtree=files_subtree --preserve-merges --onto
> files-master master &&
> verbose test "$(commit_message HEAD~)" = "files_subtree/master4"
> @@ -53,7 +55,9 @@ 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
> &&
> + git fast-export --no-data HEAD -- files_subtree/ \
> + | sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" \
> + | git fast-import --force --quiet &&
> 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 +68,9 @@ 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
> &&
> + git fast-export --no-data HEAD -- files_subtree/ \
> + | sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" \
> + | git fast-import --force --quiet &&
> 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 +81,9 @@ 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
> &&
> + git fast-export --no-data HEAD -- files_subtree/ \
> + | sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" \
> + | git fast-import --force --quiet &&
> 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 +94,9 @@ 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
> &&
> + git fast-export --no-data HEAD -- files_subtree/ \
> + | sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" \
> + | git fast-import --force --quiet &&
> 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 +106,9 @@ 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
> &&
> + git fast-export --no-data HEAD -- files_subtree/ \
> + | sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" \
> + | git fast-import --force --quiet &&
> 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 +118,9 @@ 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
> &&
> + git fast-export --no-data HEAD -- files_subtree/ \
> + | sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" \
> + | git fast-import --force --quiet &&
> 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 +129,9 @@ 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
> &&
> + git fast-export --no-data HEAD -- files_subtree/ \
> + | sed -e "s%\([0-9a-f]\{40\} \)files_subtree/%\1%" \
> + | git fast-import --force --quiet &&
> git commit -m "Empty commit" --allow-empty &&
> git rebase -Xsubtree=files_subtree --onto files-master master &&
> verbose test "$(commit_message HEAD)" = "Empty commit"
>
