7cae7627c4
Turn on sparse index and remove ensure_full_index(). Before this patch, `git-grep` utilizes the ensure_full_index() method to expand the index and search all the entries. Because this method requires walking all the trees and constructing the index, it is the slow part within the whole command. To achieve better performance, this patch uses grep_tree() to search the sparse directory entries and get rid of the ensure_full_index() method. Why grep_tree() is a better choice over ensure_full_index()? 1) grep_tree() is as correct as ensure_full_index(). grep_tree() looks into every sparse-directory entry (represented by a tree) recursively when looping over the index, and the result of doing so matches the result of expanding the index. 2) grep_tree() utilizes pathspecs to limit the scope of searching. ensure_full_index() always expands the index, which means it will always walk all the trees and blobs in the repo without caring if the user only wants a subset of the content, i.e. using a pathspec. On the other hand, grep_tree() will only search the contents that match the pathspec, and thus possibly walking fewer trees. 3) grep_tree() does not construct and copy back a new index, while ensure_full_index() does. This also saves some time. ---------------- Performance test - Summary: p2000 tests demonstrate a ~71% execution time reduction for `git grep --cached bogus -- "f2/f1/f1/*"` using tree-walking logic. However, notice that this result varies depending on the pathspec given. See below "Command used for testing" for more details. Test HEAD~ HEAD ------------------------------------------------------- 2000.78: git grep ... (full-v3) 0.35 0.39 (≈) 2000.79: git grep ... (full-v4) 0.36 0.30 (≈) 2000.80: git grep ... (sparse-v3) 0.88 0.23 (-73.8%) 2000.81: git grep ... (sparse-v4) 0.83 0.26 (-68.6%) - Command used for testing: git grep --cached bogus -- "f2/f1/f1/*" The reason for specifying a pathspec is that, if we don't specify a pathspec, then grep_tree() will walk all the trees and blobs to find the pattern, and the time consumed doing so is not too different from using the original ensure_full_index() method, which also spends most of the time walking trees. However, when a pathspec is specified, this latest logic will only walk the area of trees enclosed by the pathspec, and the time consumed is reasonably a lot less. Generally speaking, because the performance gain is acheived by walking less trees, which are specified by the pathspec, the HEAD time v.s. HEAD~ time in sparse-v[3|4], should be proportional to "pathspec enclosed area" v.s. "all area", respectively. Namely, the wider the <pathspec> is encompassing, the less the performance difference between HEAD~ and HEAD, and vice versa. That is, if we don't specify a pathspec, the performance difference [1] is indistinguishable: both methods walk all the trees and take generally same amount of time (even with the index construction time included for ensure_full_index()). [1] Performance test result without pathspec (hence walking all trees): Command used: git grep --cached bogus Test HEAD~ HEAD --------------------------------------------------- 2000.78: git grep ... (full-v3) 6.17 5.19 (≈) 2000.79: git grep ... (full-v4) 6.19 5.46 (≈) 2000.80: git grep ... (sparse-v3) 6.57 6.44 (≈) 2000.81: git grep ... (sparse-v4) 6.65 6.28 (≈) -------------------------- NEEDSWORK about submodules There are a few NEEDSWORKs that belong to improvements beyond this topic. See the NEEDSWORK in builtin/grep.c::grep_submodule() for more context. The other two NEEDSWORKs in t1092 are also relative. Suggested-by: Derrick Stolee <derrickstolee@github.com> Helped-by: Derrick Stolee <derrickstolee@github.com> Helped-by: Victoria Dye <vdye@github.com> Helped-by: Elijah Newren <newren@gmail.com> Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
130 lines
3.5 KiB
Bash
Executable File
130 lines
3.5 KiB
Bash
Executable File
#!/bin/sh
|
|
|
|
test_description="test performance of Git operations using the index"
|
|
|
|
. ./perf-lib.sh
|
|
|
|
test_perf_default_repo
|
|
|
|
SPARSE_CONE=f2/f4
|
|
|
|
test_expect_success 'setup repo and indexes' '
|
|
git reset --hard HEAD &&
|
|
|
|
# Remove submodules from the example repo, because our
|
|
# duplication of the entire repo creates an unlikely data shape.
|
|
if git config --file .gitmodules --get-regexp "submodule.*.path" >modules
|
|
then
|
|
git rm $(awk "{print \$2}" modules) &&
|
|
git commit -m "remove submodules" || return 1
|
|
fi &&
|
|
|
|
echo bogus >a &&
|
|
cp a b &&
|
|
git add a b &&
|
|
git commit -m "level 0" &&
|
|
BLOB=$(git rev-parse HEAD:a) &&
|
|
OLD_COMMIT=$(git rev-parse HEAD) &&
|
|
OLD_TREE=$(git rev-parse HEAD^{tree}) &&
|
|
|
|
for i in $(test_seq 1 3)
|
|
do
|
|
cat >in <<-EOF &&
|
|
100755 blob $BLOB a
|
|
040000 tree $OLD_TREE f1
|
|
040000 tree $OLD_TREE f2
|
|
040000 tree $OLD_TREE f3
|
|
040000 tree $OLD_TREE f4
|
|
EOF
|
|
NEW_TREE=$(git mktree <in) &&
|
|
NEW_COMMIT=$(git commit-tree $NEW_TREE -p $OLD_COMMIT -m "level $i") &&
|
|
OLD_TREE=$NEW_TREE &&
|
|
OLD_COMMIT=$NEW_COMMIT || return 1
|
|
done &&
|
|
|
|
git sparse-checkout init --cone &&
|
|
git sparse-checkout set $SPARSE_CONE &&
|
|
git checkout -b wide $OLD_COMMIT &&
|
|
|
|
for l2 in f1 f2 f3 f4
|
|
do
|
|
echo more bogus >>$SPARSE_CONE/$l2/a &&
|
|
git commit -a -m "edit $SPARSE_CONE/$l2/a" || return 1
|
|
done &&
|
|
|
|
git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . full-v3 &&
|
|
(
|
|
cd full-v3 &&
|
|
git sparse-checkout init --cone &&
|
|
git sparse-checkout set $SPARSE_CONE &&
|
|
git config index.version 3 &&
|
|
git update-index --index-version=3 &&
|
|
git checkout HEAD~4
|
|
) &&
|
|
git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . full-v4 &&
|
|
(
|
|
cd full-v4 &&
|
|
git sparse-checkout init --cone &&
|
|
git sparse-checkout set $SPARSE_CONE &&
|
|
git config index.version 4 &&
|
|
git update-index --index-version=4 &&
|
|
git checkout HEAD~4
|
|
) &&
|
|
git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-v3 &&
|
|
(
|
|
cd sparse-v3 &&
|
|
git sparse-checkout init --cone --sparse-index &&
|
|
git sparse-checkout set $SPARSE_CONE &&
|
|
git config index.version 3 &&
|
|
git update-index --index-version=3 &&
|
|
git checkout HEAD~4
|
|
) &&
|
|
git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-v4 &&
|
|
(
|
|
cd sparse-v4 &&
|
|
git sparse-checkout init --cone --sparse-index &&
|
|
git sparse-checkout set $SPARSE_CONE &&
|
|
git config index.version 4 &&
|
|
git update-index --index-version=4 &&
|
|
git checkout HEAD~4
|
|
)
|
|
'
|
|
|
|
test_perf_on_all () {
|
|
command="$@"
|
|
for repo in full-v3 full-v4 \
|
|
sparse-v3 sparse-v4
|
|
do
|
|
test_perf "$command ($repo)" "
|
|
(
|
|
cd $repo &&
|
|
echo >>$SPARSE_CONE/a &&
|
|
$command
|
|
)
|
|
"
|
|
done
|
|
}
|
|
|
|
test_perf_on_all git status
|
|
test_perf_on_all 'git stash && git stash pop'
|
|
test_perf_on_all 'echo >>new && git stash -u && git stash pop'
|
|
test_perf_on_all git add -A
|
|
test_perf_on_all git add .
|
|
test_perf_on_all git commit -a -m A
|
|
test_perf_on_all git checkout -f -
|
|
test_perf_on_all "git sparse-checkout add f2/f3/f1 && git sparse-checkout set $SPARSE_CONE"
|
|
test_perf_on_all git reset
|
|
test_perf_on_all git reset --hard
|
|
test_perf_on_all git reset -- does-not-exist
|
|
test_perf_on_all git diff
|
|
test_perf_on_all git diff --cached
|
|
test_perf_on_all git blame $SPARSE_CONE/a
|
|
test_perf_on_all git blame $SPARSE_CONE/f3/a
|
|
test_perf_on_all git read-tree -mu HEAD
|
|
test_perf_on_all git checkout-index -f --all
|
|
test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
|
|
test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
|
|
test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
|
|
|
|
test_done
|