[v3,10/13] merge-ort: preserve cached renames for the appropriate side

Commit Message

Elijah Newren May 20, 2021, 6:09 a.m. UTC

From: Elijah Newren <[e-mail]>

Previous commits created an in-memory cache of the results of rename
detection, and added logic to detect when that cache could appropriately
be used in a subsequent merge operation -- but we were still
unconditionally clearing the cache with each new merge operation anyway.
If it is valid to reuse the cache from one of the two sides of history,
preserve that side.

Signed-off-by: Elijah Newren <[e-mail]>
---
 merge-ort.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

Patch

diff --git a/merge-ort.c b/merge-ort.c
index 6d2b53a4943f..8d4b2ec40e3d 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -487,17 +487,18 @@  static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
 	/* Free memory used by various renames maps */
 	for (i = MERGE_SIDE1; i <= MERGE_SIDE2; ++i) {
 		strintmap_func(&renames->dirs_removed[i]);
-
-		partial_clear_dir_rename_count(&renames->dir_rename_count[i]);
-		if (!reinitialize)
-			strmap_clear(&renames->dir_rename_count[i], 1);
-
 		strmap_func(&renames->dir_renames[i], 0);
-
 		strintmap_func(&renames->relevant_sources[i]);
-		strset_func(&renames->cached_target_names[i]);
-		strmap_func(&renames->cached_pairs[i], 1);
-		strset_func(&renames->cached_irrelevant[i]);
+		if (!reinitialize)
+			assert(renames->cached_pairs_valid_side == 0);
+		if (i != renames->cached_pairs_valid_side) {
+			strset_func(&renames->cached_target_names[i]);
+			strmap_func(&renames->cached_pairs[i], 1);
+			strset_func(&renames->cached_irrelevant[i]);
+			partial_clear_dir_rename_count(&renames->dir_rename_count[i]);
+			if (!reinitialize)
+				strmap_clear(&renames->dir_rename_count[i], 1);
+		}
 	}
 	renames->cached_pairs_valid_side = 0;
 	renames->dir_rename_mask = 0;
@@ -2456,6 +2457,7 @@  static void detect_regular_renames(struct merge_options *opt,
 		return;
 	}
 
+	partial_clear_dir_rename_count(&renames->dir_rename_count[side_index]);
 	repo_diff_setup(opt->repo, &diff_opts);
 	diff_opts.flags.recursive = 1;
 	diff_opts.flags.rename_empty = 0;