From 6ccdfc2a206d8266ad7613999a0d3f6acdf44c89 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Thu, 5 Nov 2020 00:22:40 +0000 Subject: strmap: enable faster clearing and reusing of strmaps When strmaps are used heavily, such as is done by my new merge-ort algorithm, and strmaps need to be cleared but then re-used (because of e.g. picking multiple commits to cherry-pick, or due to a recursive merge having several different merges while recursing), free-ing and reallocating map->table repeatedly can add up in time, especially since it will likely be reallocated to a much smaller size but the previous merge provides a good guide to the right size to use for the next merge. Introduce strmap_partial_clear() to take advantage of this type of situation; it will act similar to strmap_clear() except that map->table's entries are zeroed instead of map->table being free'd. Making use of this function reduced the cost of clear_or_reinit_internal_opts() by about 20% in mert-ort, and dropped the overall runtime of my rebase testcase by just under 2%. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano --- strmap.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'strmap.c') diff --git a/strmap.c b/strmap.c index 829f1bc095..c410c5241a 100644 --- a/strmap.c +++ b/strmap.c @@ -64,6 +64,12 @@ void strmap_clear(struct strmap *map, int free_values) hashmap_clear(&map->map); } +void strmap_partial_clear(struct strmap *map, int free_values) +{ + strmap_free_entries_(map, free_values); + hashmap_partial_clear(&map->map); +} + void *strmap_put(struct strmap *map, const char *str, void *data) { struct strmap_entry *entry = find_strmap_entry(map, str); -- cgit v1.2.3