1 files changed, 15 insertions, 0 deletions
diff --git a/src/libdatastruct/avlnode_rotate.c b/src/libdatastruct/avlnode_rotate.c
new file mode 100644
index 0000000..fe06994
--- /dev/null
+++ b/src/libdatastruct/avlnode_rotate.c
@@ -0,0 +1,15 @@
+/* ISC license. */
+
+#include <skalibs/avlnode.h>
+#include "avlnode-internal.h"
+
+unsigned int avlnode_rotate (avlnode_ref s, unsigned int max, unsigned int i, int h)
+{
+  register unsigned int j = s[i].child[!h] ;
+  s[i].child[!h] = s[j].child[h] ;
+  s[j].child[h] = i ;
+  if (s[j].balance * avlnode_sfromu(h) < 0) s[i].balance = s[j].balance = 0 ;
+  else s[j].balance = avlnode_sfromu(h) ;
+  (void)max ;
+  return j ;
+}