hmap: New function hmap_moved().

diff --git a/lib/hmap.h b/lib/hmap.h
index 5c6a54b14793d42e2f72508991b82f92dbb0a4a8..9a35c42c197ccee980741df93f0a3589a767fe02 100644 (file)
--- a/lib/hmap.h
+++ b/lib/hmap.h
@@ -78,6 +78,8 @@ static inline void hmap_insert_fast(struct hmap *,
                                     struct hmap_node *, size_t hash);
 static inline void hmap_insert(struct hmap *, struct hmap_node *, size_t hash);
 static inline void hmap_remove(struct hmap *, struct hmap_node *);
+static inline void hmap_moved(struct hmap *,
+                              struct hmap_node *, struct hmap_node *);
 
 /* Search. */
 #define HMAP_FOR_EACH_WITH_HASH(NODE, STRUCT, MEMBER, HASH, HMAP)       \
@@ -165,6 +167,19 @@ hmap_remove(struct hmap *hmap, struct hmap_node *node)
     hmap->n--;
 }
 
+/* Adjusts 'hmap' to compensate for 'old_node' having moved position in memory
+ * to 'node' (e.g. due to realloc()). */
+static inline void
+hmap_moved(struct hmap *hmap,
+           struct hmap_node *old_node, struct hmap_node *node)
+{
+    struct hmap_node **bucket = &hmap->buckets[node->hash & hmap->mask];
+    while (*bucket != old_node) {
+        bucket = &(*bucket)->next;
+    }
+    *bucket = node;
+}
+
 static inline struct hmap_node *
 hmap_next_with_hash__(const struct hmap_node *node, size_t hash)
 {