From: Igor Sysoev <igor@sysoev.ru>
Date: Fri, 20 Jan 2017 13:10:48 +0000 (+0300)
Subject: A small rbtree insert fixup optimization.
X-Git-Tag: 0.1.8~1
X-Git-Url: http://git.kaiwu.me/postgresql/log/contrib/postgres_fdw/%7B@url%7D?a=commitdiff_plain;h=c1efa5e66158d6dc816523a908a030731a0ec330;p=njs.git

A small rbtree insert fixup optimization.

Thanks to 洪志道 (Hong Zhi Dao).
---

diff --git a/nxt/nxt_rbtree.c b/nxt/nxt_rbtree.c
index 24cb4e6f..852317d4 100644
--- a/nxt/nxt_rbtree.c
+++ b/nxt/nxt_rbtree.c
@@ -135,8 +135,12 @@ nxt_rbtree_insert_fixup(nxt_rbtree_node_t *node)
                 grandparent = parent->parent;
                 grandparent->color = NXT_RBTREE_RED;
                 nxt_rbtree_right_rotate(grandparent);
-
-                continue;
+                /*
+                 * nxt_rbtree_right_rotate() does not change node->parent
+                 * color which is now black, so testing color is not required
+                 * to return from function.
+                 */
+                return;
             }
 
         } else {
@@ -156,7 +160,8 @@ nxt_rbtree_insert_fixup(nxt_rbtree_node_t *node)
                 grandparent->color = NXT_RBTREE_RED;
                 nxt_rbtree_left_rotate(grandparent);
 
-                continue;
+                /* See the comment in the symmetric branch above. */
+                return;
             }
         }