sset, smap, hmapx: Reserve hash map space while cloning.

This makes the clone a little bit faster by avoiding multiple
incremental expansions with re-allocations on big sets.

Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

3 files changed, 6 insertions, 0 deletions

diff --git a/lib/hmapx.c b/lib/hmapx.c
index 68192fc2c..bb9ec11c5 100644
--- a/lib/hmapx.c
+++ b/lib/hmapx.c
@@ -66,6 +66,8 @@ hmapx_clone(struct hmapx *map, const struct hmapx *orig)
     struct hmapx_node *node;
 
     hmapx_init(map);
+    hmap_reserve(&map->map, hmapx_count(orig));
+
     HMAP_FOR_EACH (node, hmap_node, &orig->map) {
         hmapx_add__(map, node->data, node->hmap_node.hash);
     }
diff --git a/lib/smap.c b/lib/smap.c
index b23eeb52d..c1633e2a1 100644
--- a/lib/smap.c
+++ b/lib/smap.c
@@ -310,6 +310,8 @@ smap_clone(struct smap *dst, const struct smap *src)
     const struct smap_node *node;
 
     smap_init(dst);
+    hmap_reserve(&dst->map, smap_count(src));
+
     SMAP_FOR_EACH (node, src) {
         smap_add__(dst, xstrdup(node->key), xstrdup(node->value),
                    node->node.hash);
diff --git a/lib/sset.c b/lib/sset.c
index 6fbaa9d60..aa1790020 100644
--- a/lib/sset.c
+++ b/lib/sset.c
@@ -79,6 +79,8 @@ sset_clone(struct sset *set, const struct sset *orig)
     struct sset_node *node;
 
     sset_init(set);
+    hmap_reserve(&set->map, sset_count(orig));
+
     HMAP_FOR_EACH (node, hmap_node, &orig->map) {
         sset_add__(set, node->name, strlen(node->name),
                    node->hmap_node.hash);