ck_hs: Add ck_hs_reset_size operation.

The ck_hs_reset_size operation takes an additional argument
that allows the user to specify the size of the new generation
of the hashset.

include/ck_hs.h

@@ -98,6 +98,7 @@ void *ck_hs_remove(ck_hs_t *, unsigned long, const void *);
 bool ck_hs_grow(ck_hs_t *, unsigned long);
 unsigned long ck_hs_count(ck_hs_t *);
 bool ck_hs_reset(ck_hs_t *);
+bool ck_hs_reset_size(ck_hs_t *, unsigned long);
 void ck_hs_stat(ck_hs_t *, struct ck_hs_stat *);
 
 #endif /* _CK_HS_H */

src/ck_hs.c

@@ -167,12 +167,12 @@ ck_hs_map_create(struct ck_hs *hs, unsigned long entries)
 }
 
 bool
-ck_hs_reset(struct ck_hs *hs)
+ck_hs_reset_size(struct ck_hs *hs, unsigned long capacity)
 {
 	struct ck_hs_map *map, *previous;
 
 	previous = hs->map;
-	map = ck_hs_map_create(hs, previous->capacity);
+	map = ck_hs_map_create(hs, capacity);
 	if (map == NULL)
 		return false;
 
@@ -181,6 +181,15 @@ ck_hs_reset(struct ck_hs *hs)
 	return true;
 }
 
+bool
+ck_hs_reset(struct ck_hs *hs)
+{
+	struct ck_hs_map *previous;
+
+	previous = hs->map;
+	return ck_hs_reset_size(hs, previous->capacity);
+}
+
 static inline unsigned long
 ck_hs_map_probe_next(struct ck_hs_map *map,
     unsigned long offset,