uniq_skiplist.h: add function uniq_skiplist_iterator_at

HISTORY

@@ -1,6 +1,7 @@
 
-Version 1.53  2021-06-26
+Version 1.53  2021-06-30
   * process_action support action status
+  * uniq_skiplist.h: add function uniq_skiplist_iterator_at
 
 Version 1.52  2021-06-08
   * process_stop more gracefully (kill -9 on timeout)

src/uniq_skiplist.h

@@ -192,6 +192,20 @@ static inline void *uniq_skiplist_next(UniqSkiplistIterator *iterator)
     return data;
 }
 
+static inline void uniq_skiplist_iterator_at(UniqSkiplist *sl,
+        const int offset, UniqSkiplistIterator *iterator)
+{
+    int i;
+
+    iterator->current = sl->top->links[0];
+    iterator->tail = sl->factory->tail;
+
+    i = 0;
+    while (i++ < offset && iterator->current != iterator->tail) {
+        iterator->current = iterator->current->links[0];
+    }
+}
+
 static inline int uniq_skiplist_iterator_count(UniqSkiplistIterator *iterator)
 {
     volatile UniqSkiplistNode *current;