From 8d9a7cdfda4c883e83d6ea7b57d0a1d989a7d439 Mon Sep 17 00:00:00 2001 From: Toon Claes Date: Tue, 5 Aug 2025 11:33:58 +0200 Subject: last-modified: use Bloom filters when available Our 'git last-modified' performs a revision walk, and computes a diff at each point in the walk to figure out whether a given revision changed any of the paths it considers interesting. When changed-path Bloom filters are available, we can avoid computing many such diffs. Before computing a diff, we first check if any of the remaining paths of interest were possibly changed at a given commit by consulting its Bloom filter. If any of them are, we are resigned to compute the diff. If none of those queries returned "maybe", we know that the given commit doesn't contain any changed paths which are interesting to us. So, we can avoid computing it in this case. Comparing the perf test results on git.git: Test HEAD~ HEAD ------------------------------------------------------------------------------------ 8020.1: top-level last-modified 4.49(4.34+0.11) 2.22(2.05+0.09) -50.6% 8020.2: top-level recursive last-modified 5.64(5.45+0.11) 5.62(5.30+0.11) -0.4% 8020.3: subdir last-modified 0.11(0.06+0.04) 0.07(0.03+0.04) -36.4% Based-on-patch-by: Taylor Blau Signed-off-by: Toon Claes Signed-off-by: Junio C Hamano --- commit-graph.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'commit-graph.c') diff --git a/commit-graph.c b/commit-graph.c index bd7b6f5338..dc1f29dd2f 100644 --- a/commit-graph.c +++ b/commit-graph.c @@ -820,7 +820,12 @@ int corrected_commit_dates_enabled(struct repository *r) struct bloom_filter_settings *get_bloom_filter_settings(struct repository *r) { - struct commit_graph *g = r->objects->commit_graph; + struct commit_graph *g; + + if (!prepare_commit_graph(r)) + return NULL; + + g = r->objects->commit_graph; while (g) { if (g->bloom_filter_settings) return g->bloom_filter_settings; -- cgit v1.2.3