pack-write: skip *.rev work when not writing *.rev

avar · gitster · commit 8fe8bae9d28e · 2021-09-07T22:04:03.000-07:00
Fix a performance regression introduced in a587b5a (pack-write.c: extract 'write_rev_file_order', 2021-03-30) and stop needlessly allocating the "pack_order" array and sorting it with "pack_order_cmp()", only to throw that work away when we discover that we're not writing *.rev files after all. This redundant work was not present in the original version of this code added in 8ef50d9 (pack-write.c: prepare to write 'pack-*.rev' files, 2021-01-25). There we'd call write_rev_file() from e.g. finish_tmp_packfile(), but we'd "return NULL" early in write_rev_file() if not doing a "WRITE_REV" or "WRITE_REV_VERIFY". Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/pack-write.c b/pack-write.c
@@ -224,6 +224,9 @@ const char *write_rev_file(const char *rev_name,
 	uint32_t i;
 	const char *ret;
 
+	if (!(flags & WRITE_REV) && !(flags & WRITE_REV_VERIFY))
+		return NULL;
+
 	ALLOC_ARRAY(pack_order, nr_objects);
 	for (i = 0; i < nr_objects; i++)
 		pack_order[i] = i;
