Merge branch 'ms/merge-recursive-string-list-micro-optimization'

Rename processing in the recursive merge backend has seen a micro
optimization.

* ms/merge-recursive-string-list-micro-optimization:
  merge-recursive: optimize time complexity for process_renames
This commit is contained in:
Junio C Hamano 2025-03-03 08:53:02 -08:00
commit 85e342adbd

View File

@ -2758,23 +2758,22 @@ static int process_renames(struct merge_options *opt,
const struct rename *sre;
/*
* FIXME: As string-list.h notes, it's O(n^2) to build a sorted
* string_list one-by-one, but O(n log n) to build it unsorted and
* then sort it. Note that as we build the list, we do not need to
* check if the existing destination path is already in the list,
* because the structure of diffcore_rename guarantees we won't
* have duplicates.
* Note that as we build the list, we do not need to check if the
* existing destination path is already in the list, because the
* structure of diffcore_rename guarantees we won't have duplicates.
*/
for (i = 0; i < a_renames->nr; i++) {
sre = a_renames->items[i].util;
string_list_insert(&a_by_dst, sre->pair->two->path)->util
string_list_append(&a_by_dst, sre->pair->two->path)->util
= (void *)sre;
}
for (i = 0; i < b_renames->nr; i++) {
sre = b_renames->items[i].util;
string_list_insert(&b_by_dst, sre->pair->two->path)->util
string_list_append(&b_by_dst, sre->pair->two->path)->util
= (void *)sre;
}
string_list_sort(&a_by_dst);
string_list_sort(&b_by_dst);
for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
struct string_list *renames1, *renames2Dst;