From 48c5fbfb8976c733b7ea550675594a77777db2fa Mon Sep 17 00:00:00 2001 From: Shuqi Liang Date: Thu, 18 May 2023 11:44:54 -0400 Subject: diff-tree: integrate with sparse index 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 Signed-off-by: Shuqi Liang Signed-off-by: Junio C Hamano --- t/t1092-sparse-checkout-compatibility.sh | 42 ++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 't/t1092-sparse-checkout-compatibility.sh') 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 -- cgit v1.2.3