[PATCH v2] diff-tree: integrate with sparse index
- From
Shuqi Liang <cheskaqiqi@gmail.com>
- Date
- May 18, 2023, 15:44 UTC
- Message-ID
- <20230518154454.475487-1-cheskaqiqi@gmail.com>
- In-Reply-To
- <20230515191836.674234-1-cheskaqiqi@gmail.com>
The index is read in 'cmd_diff_tree' at two points:
1. The first index read was added in fd66bcc31ff (diff-tree: read the index so attribute checks work in bare repositories, 2017-12-06) to deal with reading '.gitattributes' content. 77efbb366ab (attr: be careful about sparse directories, 2021-09-08) established that, in a sparse index, we do _not_ try to load a '.gitattributes' file from within a sparse directory.
2. The second index access point is involved in rename detection, specifically when reading from stdin.This was initially added in f0c6b2a2fd9 ([PATCH] Optimize diff-tree -[CM]--stdin, 2005-05-27), where 'setup' was set to 'DIFF_SETUP_USE_SIZE_CACHE |DIFF_SETUP_USE_CACHE'. That assignment was later modified to drop the'DIFF_SETUP_USE_CACHE' in ff7fe37b053 (diff.c: move read_index() code back to the caller, 2018-08-13).However, 'DIFF_SETUP_USE_SIZE_CACHE' seems to be unused as of 6e0b8ed6d35 (diff.c: do not use a separate "size cache"., 2007-05-07) and nothing about 'detect_rename' otherwise indicates index usage.
Hence we can just set the requires-full-index to false for "diff-tree".
Add tests that verify that 'git diff-tree' behaves correctly when the sparse index is enabled and test to ensure the index is not expanded.
The `p2000` tests demonstrate a ~98% execution time reduction for 'git diff-tree' using a sparse index:
Test before after ----------------------------------------------------------------------- 2000.94: git diff-tree HEAD (full-v3) 0.05 0.04 -20.0% 2000.95: git diff-tree HEAD (full-v4) 0.06 0.05 -16.7% 2000.96: git diff-tree HEAD (sparse-v3) 0.59 0.01 -98.3% 2000.97: git diff-tree HEAD (sparse-v4) 0.61 0.01 -98.4% 2000.98: git diff-tree HEAD -- f2/f4/a (full-v3) 0.05 0.05 +0.0% 2000.99: git diff-tree HEAD -- f2/f4/a (full-v4) 0.05 0.04 -20.0% 2000.100: git diff-tree HEAD -- f2/f4/a (sparse-v3) 0.58 0.01 -98.3% 2000.101: git diff-tree HEAD -- f2/f4/a (sparse-v4) 0.55 0.01 -98.2%
Helped-by: Victoria Dye <vdye@github.com> Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com> --- Change since v1:
* Update commit message. * Use existing test repo to simplify the test. * Add test to ensure index won't expand regardless of 'diff-tree' a file inside or outside the cone
Range-diff against v1: 1: 47049834d1 < -: ---------- diff-tree: integrate with sparse index -: ---------- > 1: a24605f579 diff-tree: integrate with sparse index
builtin/diff-tree.c | 4 +++ t/perf/p2000-sparse-operations.sh | 2 ++ t/t1092-sparse-checkout-compatibility.sh | 42 ++++++++++++++++++++++++ 3 files changed, 48 insertions(+)
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c index 0b02c62b85..c0540317fb 100644 --- a/builtin/diff-tree.c +++ b/builtin/diff-tree.c @@ -122,6 +122,10 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix) usage(diff_tree_usage); git_config(git_diff_basic_config, NULL); /* no "diff" UI options */ + + prepare_repo_settings(the_repository); + the_repository->settings.command_requires_full_index = 0; + repo_init_revisions(the_repository, opt, prefix); if (repo_read_index(the_repository) < 0) die(_("index file corrupt")); diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh index 901cc493ef..5a11910189 100755 --- a/t/perf/p2000-sparse-operations.sh +++ b/t/perf/p2000-sparse-operations.sh @@ -131,5 +131,7 @@ test_perf_on_all git describe --dirty test_perf_on_all 'echo >>new && git describe --dirty' test_perf_on_all git diff-files test_perf_on_all git diff-files -- $SPARSE_CONE/a +test_perf_on_all git diff-tree HEAD +test_perf_on_all git diff-tree HEAD -- $SPARSE_CONE/a test_done diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh index e58bfbfcb4..90f827ffe9 100755 --- a/t/t1092-sparse-checkout-compatibility.sh +++ b/t/t1092-sparse-checkout-compatibility.sh @@ -2170,4 +2170,46 @@ test_expect_success 'sparse index is not expanded: diff-files' ' ensure_not_expanded diff-files -- "deep/*" ' +test_expect_success 'diff-tree' ' + init_repos && + + # Test change inside sparse cone + tree1=$(git -C sparse-index rev-parse HEAD^{tree}) && + tree2=$(git -C sparse-index rev-parse update-deep^{tree}) && + test_all_match git diff-tree $tree1 $tree2 && + test_all_match git diff-tree $tree1 $tree2 -- deep/a && + test_all_match git diff-tree HEAD update-deep && + test_all_match git diff-tree HEAD update-deep -- deep/a && + + # Test change outside sparse cone + tree3=$(git -C sparse-index rev-parse update-folder1^{tree}) && + test_all_match git diff-tree $tree1 $tree3 && + test_all_match git diff-tree $tree1 $tree3 -- folder1/a && + test_all_match git diff-tree HEAD update-folder1 && + test_all_match git diff-tree HEAD update-folder1 -- folder1/a && + + # Check that SKIP_WORKTREE files are not materialized + test_path_is_missing sparse-checkout/folder1/a && + test_path_is_missing sparse-index/folder1/a && + test_path_is_missing sparse-checkout/folder2/a && + test_path_is_missing sparse-index/folder2/a +' + +test_expect_success 'sparse-index is not expanded: diff-tree' ' + init_repos && + + tree1=$(git -C sparse-index rev-parse HEAD^{tree}) && + tree2=$(git -C sparse-index rev-parse update-deep^{tree}) && + tree3=$(git -C sparse-index rev-parse update-folder1^{tree}) && + + ensure_not_expanded diff-tree $tree1 $tree2 && + ensure_not_expanded diff-tree $tree1 $tree2 -- deep/a && + ensure_not_expanded diff-tree HEAD update-deep && + ensure_not_expanded diff-tree HEAD update-deep -- deep/a && + ensure_not_expanded diff-tree $tree1 $tree3 && + ensure_not_expanded diff-tree $tree1 $tree3 -- folder1/a && + ensure_not_expanded diff-tree HEAD update-folder1 && + ensure_not_expanded diff-tree HEAD update-folder1 -- folder1/a +' + test_done
-- 2.39.0