hashmap: introduce hash_ops to make struct Hashmap smaller

It is redundant to store 'hash' and 'compare' function pointers in
struct Hashmap separately. The functions always comprise a pair.
Store a single pointer to struct hash_ops instead.

systemd keeps hundreds of hashmaps, so this saves a little bit of
memory.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c
index 733ef6348d..33ca4d1a45 100644
--- a/src/resolve/resolved-dns-cache.c
+++ b/src/resolve/resolved-dns-cache.c
@@ -186,7 +186,7 @@ static int dns_cache_init(DnsCache *c) {
         if (r < 0)
                 return r;
 
-        r = hashmap_ensure_allocated(&c->by_key, dns_resource_key_hash_func, dns_resource_key_compare_func);
+        r = hashmap_ensure_allocated(&c->by_key, &dns_resource_key_hash_ops);
         if (r < 0)
                 return r;