From f3099647623f2b13ece56cf8cf31761c00c1c297 Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Mon, 19 Jul 2010 11:22:10 -0700 Subject: [PATCH] hmap: New function hmap_clear(). --- lib/hmap.c | 17 +++++++++++++++++ lib/hmap.h | 1 + 2 files changed, 18 insertions(+) diff --git a/lib/hmap.c b/lib/hmap.c index 1b4816d9..6bc5ea74 100644 --- a/lib/hmap.c +++ b/lib/hmap.c @@ -18,6 +18,7 @@ #include "hmap.h" #include #include +#include #include "coverage.h" #include "random.h" #include "util.h" @@ -42,6 +43,22 @@ hmap_destroy(struct hmap *hmap) } } +/* Removes all node from 'hmap', leaving it ready to accept more nodes. Does + * not free memory allocated for 'hmap'. + * + * This function is appropriate when 'hmap' will soon have about as many + * elements as it before. If 'hmap' will likely have fewer elements than + * before, use hmap_destroy() followed by hmap_clear() to save memory and + * iteration time. */ +void +hmap_clear(struct hmap *hmap) +{ + if (hmap->n > 0) { + hmap->n = 0; + memset(hmap->buckets, 0, (hmap->mask + 1) * sizeof *hmap->buckets); + } +} + /* Exchanges hash maps 'a' and 'b'. */ void hmap_swap(struct hmap *a, struct hmap *b) diff --git a/lib/hmap.h b/lib/hmap.h index d5674999..92aff7f9 100644 --- a/lib/hmap.h +++ b/lib/hmap.h @@ -69,6 +69,7 @@ struct hmap { /* Initialization. */ void hmap_init(struct hmap *); void hmap_destroy(struct hmap *); +void hmap_clear(struct hmap *); void hmap_swap(struct hmap *a, struct hmap *b); void hmap_moved(struct hmap *hmap); static inline size_t hmap_count(const struct hmap *); -- 2.30.2