From e9a9981477e9d6ba3aef96e39db5736b334d7189 Mon Sep 17 00:00:00 2001 From: Derrick Stolee Date: Tue, 25 May 2021 06:59:05 -0400 Subject: [PATCH] checkout: stop expanding sparse indexes Previous changes did the necessary improvements to unpack-trees.c and diff-lib.c in order to modify a sparse index based on its comparision with a tree. The only remaining work is to remove some ensure_full_index() calls and add tests that verify that the index is not expanded in our interesting cases. Include 'switch' and 'restore' in these tests, as they share a base implementation with 'checkout'. Here are the relevant performance results from p2000-sparse-operations.sh: Test HEAD~1 HEAD -------------------------------------------------------------------------------- 2000.18: git checkout -f - (full-v3) 0.49(0.43+0.03) 0.47(0.39+0.05) -4.1% 2000.19: git checkout -f - (full-v4) 0.45(0.37+0.06) 0.42(0.37+0.05) -6.7% 2000.20: git checkout -f - (sparse-v3) 0.76(0.71+0.07) 0.04(0.03+0.04) -94.7% 2000.21: git checkout -f - (sparse-v4) 0.75(0.72+0.04) 0.05(0.06+0.04) -93.3% It is important to compare the full index case to the sparse index case, as the previous results for the sparse index were inflated by the index expansion. For index v4, this is an 88% improvement. On an internal repository with over two million paths at HEAD and a sparse-checkout definition containing ~60,000 of those paths, 'git checkout' went from 3.5s to 297ms with this change. The theoretical optimum where only those ~60,000 paths exist was 275ms, so the extra sparse directory entries contribute a 22ms overhead. Signed-off-by: Derrick Stolee --- builtin/checkout.c | 8 +++----- t/t1092-sparse-checkout-compatibility.sh | 10 +++++++++- 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/builtin/checkout.c b/builtin/checkout.c index f4cd7747d35dd1..b5d477919a7438 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -378,9 +378,6 @@ static int checkout_worktree(const struct checkout_opts *opts, if (pc_workers > 1) init_parallel_checkout(); - /* TODO: audit for interaction with sparse-index. */ - ensure_full_index(&the_index); - for (pos = 0; pos < active_nr; pos++) { struct cache_entry *ce = active_cache[pos]; if (ce->ce_flags & CE_MATCHED) { @@ -530,8 +527,6 @@ static int checkout_paths(const struct checkout_opts *opts, * Make sure all pathspecs participated in locating the paths * to be checked out. */ - /* TODO: audit for interaction with sparse-index. */ - ensure_full_index(&the_index); for (pos = 0; pos < active_nr; pos++) if (opts->overlay_mode) mark_ce_for_checkout_overlay(active_cache[pos], @@ -1593,6 +1588,9 @@ static int checkout_main(int argc, const char **argv, const char *prefix, git_config(git_checkout_config, opts); + prepare_repo_settings(the_repository); + the_repository->settings.command_requires_full_index = 0; + opts->track = BRANCH_TRACK_UNSPECIFIED; if (!opts->accept_pathspec && !opts->accept_ref) diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh index d3e34d0acaccc9..fde3b41aba8b86 100755 --- a/t/t1092-sparse-checkout-compatibility.sh +++ b/t/t1092-sparse-checkout-compatibility.sh @@ -560,7 +560,15 @@ test_expect_success 'sparse-index is not expanded' ' echo >>sparse-index/a && ensure_not_expanded commit --include a -m a && echo >>sparse-index/deep/deeper1/a && - ensure_not_expanded commit --include deep/deeper1/a -m deeper + ensure_not_expanded commit --include deep/deeper1/a -m deeper && + ensure_not_expanded checkout rename-out-to-out && + ensure_not_expanded checkout - && + ensure_not_expanded switch rename-out-to-out && + ensure_not_expanded switch - && + git -C sparse-index reset --hard && + ensure_not_expanded checkout rename-out-to-out -- deep/deeper1 && + git -C sparse-index reset --hard && + ensure_not_expanded restore -s rename-out-to-out -- deep/deeper1 ' # NEEDSWORK: a sparse-checkout behaves differently from a full checkout