From 5c276df415a52de048e961994fe7a210f3312b09 Mon Sep 17 00:00:00 2001 From: Alex Ionescu Date: Tue, 8 Nov 2005 23:33:07 +0000 Subject: [PATCH] - Implement Case 1 of RtlSplay svn path=/trunk/; revision=19073 --- reactos/lib/rtl/splaytree.c | 58 ++++++++++++++++++++++++++++++++++++- 1 file changed, 57 insertions(+), 1 deletion(-) diff --git a/reactos/lib/rtl/splaytree.c b/reactos/lib/rtl/splaytree.c index ec3a11acd27..50d28a56f54 100644 --- a/reactos/lib/rtl/splaytree.c +++ b/reactos/lib/rtl/splaytree.c @@ -127,7 +127,63 @@ RtlSplay(PRTL_SPLAY_LINKS Links) /* Case 1: P is the left child of G */ if (RtlIsLeftChild(P)) { - + /* + * N's right-child becomes P's left child and + * P's right-child becomes G's left child. + */ + RtlLeftChild(P) = RtlRightChild(N); + RtlLeftChild(G) = RtlRightChild(P); + + /* + * If they exist, update their parent pointers too, + * since they've changed trees + */ + if (RtlLeftChild(P)) RtlParent(RtlLeftChild(P)) = P; + if (RtlLeftChild(G)) RtlParent(RtlLeftChild(G)) = G; + + /* + * Now we'll shove N all the way to the top. + * Check if G is the root first. + */ + if (RtlIsRoot(G)) + { + /* G doesn't have a parent, so N will become the root! */ + RtlParent(N) = N; + } + else + { + /* G has a parent, so inherit it since we take G's place */ + RtlParent(N) = RtlParent(G); + + /* + * Now find out who was referencing G and have it reference + * N instead, since we're taking G's place. + */ + if (RtlIsLeftChild(G)) + { + /* + * G was a left child, so change its parent's left + * child link to point to N now. + */ + RtlLeftChild(RtlParent(G)) = N; + } + else + { + /* + * G was a right child, so change its parent's right + * child link to point to N now. + */ + RtlLeftChild(RtlParent(G)) = N; + } + } + + /* Now N is on top, so P has become its child */ + RtlRightChild(N) = P; + RtlParent(P) = N; + + /* N is on top, P is its child, so G is grandchild */ + RtlRightChild(P) = G; + RtlParent(G) = P; } /* Case 3: P is the right child of G */ else if (RtlIsRightChild(P)) -- 2.17.1