[PATCH v2 6/8] merge-ort: use relevant_sources to filter possible rename sources

From: Elijah Newren via GitGitGadget <gitgitgadget@gmail.com>
Date: Mar 9, 2021, 00:09 UTC
Message-ID: <d62fdee45ad344a09062e2ab73702d1093c12efc.1615248599.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.845.v2.git.1615248599.gitgitgadget@gmail.com>

From: Elijah Newren <newren@gmail.com>

The past several commits determined conditions when rename sources might be needed, and filled a relevant_sources strset with those paths. Pass these along to diffcore_rename_extended() to use to limit the sources that we need to detect renames for.

For the testcases mentioned in commit 557ac0350d ("merge-ort: begin performance work; instrument with trace2_region_* calls", 2020-10-28), this change improves the performance as follows:

                            Before                  After
    no-renames:       12.596 s ±  0.061 s     6.003 s ±  0.048 s
    mega-renames:    130.465 s ±  0.259 s   114.009 s ±  0.236 s
    just-one-mega:     3.958 s ±  0.010 s     3.489 s ±  0.017 s

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 merge-ort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/merge-ort.c b/merge-ort.c
index 27acaa7380be..66892c63cee2 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -2209,7 +2209,7 @@ static void detect_regular_renames(struct merge_options *opt,
 	diff_queued_diff = renames->pairs[side_index];
 	trace2_region_enter("diff", "diffcore_rename", opt->repo);
 	diffcore_rename_extended(&diff_opts,
-				 NULL,
+				 &renames->relevant_sources[side_index],
 				 &renames->dirs_removed[side_index],
 				 &renames->dir_rename_count[side_index]);
 	trace2_region_leave("diff", "diffcore_rename", opt->repo);

-- 
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