/*
* @implemented
*/
PRTL_SPLAY_LINKS
NTAPI
RtlRealSuccessor(PRTL_SPLAY_LINKS Links)
{
PRTL_SPLAY_LINKS Child;
/* Get the right child */
Child = RtlRightChild(Links);
if (Child)
{
/* Get left-most child */
while (RtlLeftChild(Child)) Child = RtlLeftChild(Child);
return Child;
}
/* We don't have a right child, keep looping until we find our parent */
Child = Links;
while (RtlIsRightChild(Child)) Child = RtlParent(Child);
/* The parent should be a left child, return the real successor */
if (RtlIsLeftChild(Child)) return RtlParent(Child);
/* The parent isn't a right child, so no real successor for us */
return NULL;
}
PRTL_SPLAY_LINKS
RtlRealPredecessor (
IN PRTL_SPLAY_LINKS Links
)
/*++
Routine Description:
The RealPredecessor function takes as input a pointer to a splay link
in a tree and returns a pointer to the predecessor of the input node
within the entire tree. If there is not a predecessor, the return value
is NULL.
Arguments:
Links - Supplies a pointer to a splay link in a tree.
Return Value:
PRTL_SPLAY_LINKS - returns a pointer to the predecessor in the entire tree
--*/
{
PRTL_SPLAY_LINKS Ptr;
/*
first check to see if there is a left subtree to the input link
if there is then the real predecessor is the right most node in
the left subtree. That is find and return P in the following diagram
Links
/
.
.
.
P
/
*/
if ((Ptr = RtlLeftChild(Links)) != NULL) {
while (RtlRightChild(Ptr) != NULL) {
Ptr = RtlRightChild(Ptr);
}
return Ptr;
}
/*
we do not have a left child so check to see if have a parent and if
so find the first ancestor that we are a right descendent of. That
is find and return P in the following diagram
P
\
.
.
.
Links
*/
Ptr = Links;
while (RtlIsLeftChild(Ptr)) {
Ptr = RtlParent(Ptr);
}
if (RtlIsRightChild(Ptr)) {
return RtlParent(Ptr);
}
//
// otherwise we are do not have a real predecessor so we simply return
// NULL
//
return NULL;
}
PRTL_SPLAY_LINKS
RtlSplay (
IN PRTL_SPLAY_LINKS Links
)
/*++
Routine Description:
The Splay function takes as input a pointer to a splay link in a tree
and splays the tree. Its function return value is a pointer to the
root of the splayed tree.
Arguments:
Links - Supplies a pointer to a splay link in a tree.
Return Value:
PRTL_SPLAY_LINKS - returns a pointer to the root of the splayed tree.
--*/
{
PRTL_SPLAY_LINKS L;
PRTL_SPLAY_LINKS P;
PRTL_SPLAY_LINKS G;
//
// while links is not the root we need to keep rotating it toward
// the root
//
L = Links;
while (!RtlIsRoot(L)) {
P = RtlParent(L);
G = RtlParent(P);
if (RtlIsLeftChild(L)) {
if (RtlIsRoot(P)) {
/*
we have the following case
P L
/ \ / \
L c ==> a P
/ \ / \
a b b c
*/
//
// Connect P & b
//
P->LeftChild = L->RightChild;
if (P->LeftChild != NULL) {P->LeftChild->Parent = P;}
//
// Connect L & P
//
L->RightChild = P;
P->Parent = L;
//
// Make L the root
//
L->Parent = L;
} else if (RtlIsLeftChild(P)) {
/*
we have the following case
| |
G L
/ \ / \
P d ==> a P
/ \ / \
L c b G
/ \ / \
a b c d
*/
//
// Connect P & b
//
P->LeftChild = L->RightChild;
if (P->LeftChild != NULL) {P->LeftChild->Parent = P;}
//
// Connect G & c
//
G->LeftChild = P->RightChild;
if (G->LeftChild != NULL) {G->LeftChild->Parent = G;}
//
// Connect L & Great GrandParent
//
if (RtlIsRoot(G)) {
L->Parent = L;
} else {
L->Parent = G->Parent;
*(ParentsChildPointerAddress(G)) = L;
}
//
// Connect L & P
//
L->RightChild = P;
P->Parent = L;
//
// Connect P & G
//
P->RightChild = G;
G->Parent = P;
} else { // RtlIsRightChild(Parent)
/*
we have the following case
| |
G L
/ \ / \
a P G P
/ \ / \ / \
L d ==> a b c d
/ \
b c
*/
//
// Connect G & b
//
G->RightChild = L->LeftChild;
if (G->RightChild != NULL) {G->RightChild->Parent = G;}
//
// Connect P & c
//
P->LeftChild = L->RightChild;
if (P->LeftChild != NULL) {P->LeftChild->Parent = P;}
//
// Connect L & Great GrandParent
//
if (RtlIsRoot(G)) {
L->Parent = L;
} else {
L->Parent = G->Parent;
*(ParentsChildPointerAddress(G)) = L;
}
//
// Connect L & G
//
L->LeftChild = G;
G->Parent = L;
//
// Connect L & P
//
L->RightChild = P;
P->Parent = L;
}
} else { // RtlIsRightChild(L)
if (RtlIsRoot(P)) {
/*
we have the following case
P L
/ \ / \
a L P c
/ \ / \
b c ==> a b
*/
//
// Connect P & b
//
P->RightChild = L->LeftChild;
if (P->RightChild != NULL) {P->RightChild->Parent = P;}
//
// Connect P & L
//
L->LeftChild = P;
P->Parent = L;
//
// Make L the root
//
L->Parent = L;
} else if (RtlIsRightChild(P)) {
/*
we have the following case
| |
G L
/ \ / \
a P P d
/ \ / \
b L G c
/ \ / \
c d ==> a b
*/
//
// Connect G & b
//
G->RightChild = P->LeftChild;
if (G->RightChild != NULL) {G->RightChild->Parent = G;}
//
// Connect P & c
//
P->RightChild = L->LeftChild;
if (P->RightChild != NULL) {P->RightChild->Parent = P;}
//
// Connect L & Great GrandParent
//
if (RtlIsRoot(G)) {
L->Parent = L;
} else {
L->Parent = G->Parent;
*(ParentsChildPointerAddress(G)) = L;
}
//
// Connect L & P
//
L->LeftChild = P;
P->Parent = L;
//
// Connect P & G
//
P->LeftChild = G;
G->Parent = P;
} else { // RtlIsLeftChild(P)
/*
we have the following case
| |
G L
/ \ / \
P d P G
/ \ / \ / \
a L ==> a b c d
/ \
b c
*/
//
// Connect P & b
//
P->RightChild = L->LeftChild;
if (P->RightChild != NULL) {P->RightChild->Parent = P;}
//
// Connect G & c
//
G->LeftChild = L->RightChild;
if (G->LeftChild != NULL) {G->LeftChild->Parent = G;}
//
// Connect L & Great GrandParent
//
if (RtlIsRoot(G)) {
L->Parent = L;
} else {
L->Parent = G->Parent;
*(ParentsChildPointerAddress(G)) = L;
}
//
// Connect L & P
//
L->LeftChild = P;
P->Parent = L;
//
// Connect L & G
//
L->RightChild = G;
G->Parent = L;
}
}
}
return L;
}
FORCEINLINE
VOID
RtlpDeleteAvlTreeNode(IN PRTL_AVL_TABLE Table,
IN PRTL_BALANCED_LINKS Node)
{
PRTL_BALANCED_LINKS DeleteNode = NULL, ParentNode;
PRTL_BALANCED_LINKS *Node1, *Node2;
CHAR Balance;
/* Take one of the children if possible */
if (!(RtlLeftChildAvl(Node)) || !(RtlRightChildAvl(Node))) DeleteNode = Node;
/* Otherwise, check if one side is longer */
if (!(DeleteNode) && (RtlBalance(Node) >= RtlBalancedAvlTree))
{
/* Pick the successor which will be the longest side in this case */
DeleteNode = RtlRightChildAvl(Node);
while (RtlLeftChildAvl(DeleteNode)) DeleteNode = RtlLeftChildAvl(DeleteNode);
}
else if (!DeleteNode)
{
/* Pick the predecessor which will be the longest side in this case */
DeleteNode = RtlLeftChildAvl(Node);
while (RtlRightChildAvl(DeleteNode)) DeleteNode = RtlRightChildAvl(DeleteNode);
}
/* Get the parent node */
ParentNode = RtlParentAvl(DeleteNode);
DPRINT("Parent: %p\n", ParentNode);
/* Pick which now to use based on whether or not we have a left child */
Node1 = RtlLeftChildAvl(DeleteNode) ? &DeleteNode->LeftChild : &DeleteNode->RightChild;
DPRINT("Node 1: %p %p\n", Node1, *Node1);
/* Pick which node to swap based on if we're already a left child or not */
Node2 = RtlIsLeftChildAvl(DeleteNode) ? &ParentNode->LeftChild : &ParentNode->RightChild;
DPRINT("Node 2: %p %p\n", Node2, *Node2);
/* Pick the correct balance depending on which side will get heavier */
Balance = RtlIsLeftChildAvl(DeleteNode) ? RtlLeftHeavyAvlTree : RtlRightHeavyAvlTree;
DPRINT("Balance: %lx\n", Balance);
/* Swap the children nodes, making one side heavier */
*Node2 = *Node1;
/* If the node has a child now, update its parent */
if (*Node1) RtlSetParent(*Node1, ParentNode);
/* Assume balanced root for loop optimization */
RtlSetBalance(&Table->BalancedRoot, RtlBalancedAvlTree);
/* Loop up the tree by parents */
while (TRUE)
{
/* Check if the tree's balance increased */
if (RtlBalance(ParentNode) == Balance)
{
/* Now the tree is balanced */
RtlSetBalance(ParentNode, RtlBalancedAvlTree);
}
else if (RtlBalance(ParentNode) == RtlBalancedAvlTree)
{
/* The tree has now become less balanced, since it was balanced */
RtlSetBalance(ParentNode, -Balance);
/* Deal with the loop optimization to detect loss of a tree level */
if (RtlBalance(&Table->BalancedRoot) != RtlBalancedAvlTree) Table->DepthOfTree--;
break;
}
else
{
/* The tree has become unbalanced, so a rebalance is needed */
if (RtlpRebalanceAvlTreeNode(ParentNode)) break;
/* Get the new parent after the balance */
ParentNode = RtlParentAvl(ParentNode);
}
/* Choose which balance factor to use based on which side we're on */
Balance = RtlIsRightChild(ParentNode) ?
RtlRightHeavyAvlTree : RtlLeftHeavyAvlTree;
/* Iterate up the tree */
ParentNode = RtlParentAvl(ParentNode);
}
/* Check if this isn't the node we ended up deleting directly */
if (Node == DeleteNode) return;
/* Copy the deleted node itself */
RtlpCopyAvlNodeData(DeleteNode, Node);
/* Pick the right node to unlink */
Node1 = RtlIsLeftChildAvl(Node) ?
&(RtlParentAvl(DeleteNode))->LeftChild : &(RtlParentAvl(DeleteNode))->RightChild;
*Node1 = DeleteNode;
/* Reparent as appropriate */
if (RtlLeftChildAvl(DeleteNode)) RtlSetParent(RtlLeftChildAvl(DeleteNode), DeleteNode);
if (RtlRightChildAvl(DeleteNode)) RtlSetParent(RtlRightChildAvl(DeleteNode), DeleteNode);
}
VOID
DumpTunnel (
PTUNNEL Tunnel
)
{
PRTL_SPLAY_LINKS SplayLinks, Ptr;
PTUNNEL_NODE Node;
PLIST_ENTRY Link;
ULONG Indent = 1, i;
ULONG EntryCount = 0;
BOOLEAN CountOff = FALSE;
DbgPrint("++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++\n");
DbgPrint("NumEntries = %d\n", Tunnel->NumEntries);
DbgPrint("****** Cache Tree\n");
SplayLinks = Tunnel->Cache;
if (SplayLinks == NULL) {
goto end;
}
while (RtlLeftChild(SplayLinks) != NULL) {
SplayLinks = RtlLeftChild(SplayLinks);
Indent++;
}
while (SplayLinks) {
Node = CONTAINING_RECORD( SplayLinks, TUNNEL_NODE, CacheLinks );
EntryCount++;
DumpNode(Node, Indent);
Ptr = SplayLinks;
/*
first check to see if there is a right subtree to the input link
if there is then the real successor is the left most node in
the right subtree. That is find and return P in the following diagram
Links
\
.
.
.
/
P
\
*/
if ((Ptr = RtlRightChild(SplayLinks)) != NULL) {
Indent++;
while (RtlLeftChild(Ptr) != NULL) {
Indent++;
Ptr = RtlLeftChild(Ptr);
}
SplayLinks = Ptr;
} else {
/*
we do not have a right child so check to see if have a parent and if
so find the first ancestor that we are a left decendent of. That
is find and return P in the following diagram
P
/
.
.
.
Links
*/
Ptr = SplayLinks;
while (RtlIsRightChild(Ptr)) {
Indent--;
Ptr = RtlParent(Ptr);
}
if (!RtlIsLeftChild(Ptr)) {
//
// we do not have a real successor so we simply return
// NULL
//
SplayLinks = NULL;
} else {
Indent--;
SplayLinks = RtlParent(Ptr);
}
}
}
end:
if (CountOff = (EntryCount != Tunnel->NumEntries)) {
DbgPrint("!!!!!!!!!! Splay Tree Count Mismatch (%d != %d)\n", EntryCount, Tunnel->NumEntries);
}
EntryCount = 0;
DbgPrint("****** Timer Queue\n");
for (Link = Tunnel->TimerQueue.Flink;
Link != &Tunnel->TimerQueue;
Link = Link->Flink) {
Node = CONTAINING_RECORD( Link, TUNNEL_NODE, ListLinks );
EntryCount++;
DumpNode(Node, 1);
}
if (CountOff |= (EntryCount != Tunnel->NumEntries)) {
DbgPrint("!!!!!!!!!! Timer Queue Count Mismatch (%d != %d)\n", EntryCount, Tunnel->NumEntries);
}
ASSERT(!CountOff);
DbgPrint("------------------------------------------------------------------\n");
}
/*
* @implemented
*/
PRTL_SPLAY_LINKS
NTAPI
RtlSplay(PRTL_SPLAY_LINKS Links)
{
/*
* Implementation Notes (http://en.wikipedia.org/wiki/Splay_tree):
*
* To do a splay, we carry out a sequence of rotations,
* each of which moves the target node N closer to the root.
*
* Each particular step depends on only two factors:
* - Whether N is the left or right child of its parent node, P,
* - Whether P is the left or right child of its parent, G (for grandparent node).
*
* Thus, there are four cases:
* - Case 1: N is the left child of P and P is the left child of G.
* In this case we perform a double right rotation, so that
* P becomes N's right child, and G becomes P's right child.
*
* - Case 2: N is the right child of P and P is the right child of G.
* In this case we perform a double left rotation, so that
* P becomes N's left child, and G becomes P's left child.
*
* - Case 3: N is the left child of P and P is the right child of G.
* In this case we perform a rotation so that
* G becomes N's left child, and P becomes N's right child.
*
* - Case 4: N is the right child of P and P is the left child of G.
* In this case we perform a rotation so that
* P becomes N's left child, and G becomes N's right child.
*
* Finally, if N doesn't have a grandparent node, we simply perform a
* left or right rotation to move it to the root.
*
* By performing a splay on the node of interest after every operation,
* we keep recently accessed nodes near the root and keep the tree
* roughly balanced, so that we achieve the desired amortized time bounds.
*/
PRTL_SPLAY_LINKS N, P, G;
/* N is the item we'll be playing with */
N = Links;
/* Let the algorithm run until N becomes the root entry */
while (!RtlIsRoot(N))
{
/* Now get the parent and grand-parent */
P = RtlParent(N);
G = RtlParent(P);
/* Case 1 & 3: N is left child of P */
if (RtlIsLeftChild(N))
{
/* 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.
*/
RtlRightChild(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))
{
/*
* N's left-child becomes G's right child and
* N's right-child becomes P's left child.
*/
RtlRightChild(G) = RtlLeftChild(N);
RtlLeftChild(P) = RtlRightChild(N);
/*
* If they exist, update their parent pointers too,
* since they've changed trees.
*/
if (RtlRightChild(G)) RtlParent(RtlRightChild(G)) = G;
if (RtlLeftChild(P)) RtlParent(RtlLeftChild(P)) = P;
/*
* 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.
*/
RtlRightChild(RtlParent(G)) = N;
}
}
/* Now N is on top, so G has become its left child. */
RtlLeftChild(N) = G;
RtlParent(G) = N;
/* N is on top, G is its left child, so P is right child. */
RtlRightChild(N) = P;
RtlParent(P) = N;
}
/* "Finally" case: N doesn't have a grandparent => P is root */
else
{
/* P's left-child becomes N's right child */
RtlLeftChild(P) = RtlRightChild(N);
/* If it exists, update its parent pointer too */
if (RtlLeftChild(P)) RtlParent(RtlLeftChild(P)) = P;
/* Now make N the root, no need to worry about references */
N->Parent = N;
/* And make P its right child */
N->RightChild = P;
P->Parent = N;
}
}
/* Case 2 & 4: N is right child of P */
else
{
/* Case 2: P is the right child of G */
if (RtlIsRightChild(P))
{
/*
* P's left-child becomes G's right child and
* N's left-child becomes P's right child.
*/
RtlRightChild(G) = RtlLeftChild(P);
RtlRightChild(P) = RtlLeftChild(N);
/*
* If they exist, update their parent pointers too,
* since they've changed trees.
*/
if (RtlRightChild(G)) RtlParent(RtlRightChild(G)) = G;
if (RtlRightChild(P)) RtlParent(RtlRightChild(P)) = P;
/*
* 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.
*/
RtlRightChild(RtlParent(G)) = N;
}
}
/* Now N is on top, so P has become its child. */
RtlLeftChild(N) = P;
RtlParent(P) = N;
/* N is on top, P is its child, so G is grandchild. */
RtlLeftChild(P) = G;
RtlParent(G) = P;
}
/* Case 4: P is the left child of G */
else if (RtlIsLeftChild(P))
{
/*
* N's left-child becomes G's right child and
* N's right-child becomes P's left child.
*/
RtlRightChild(P) = RtlLeftChild(N);
RtlLeftChild(G) = RtlRightChild(N);
/*
* If they exist, update their parent pointers too,
* since they've changed trees.
*/
if (RtlRightChild(P)) RtlParent(RtlRightChild(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.
*/
RtlRightChild(RtlParent(G)) = N;
}
}
/* Now N is on top, so P has become its left child. */
RtlLeftChild(N) = P;
RtlParent(G) = N;
/* N is on top, P is its left child, so G is right child. */
RtlRightChild(N) = G;
RtlParent(P) = N;
}
/* "Finally" case: N doesn't have a grandparent => P is root */
else
{
/* P's right-child becomes N's left child */
RtlRightChild(P) = RtlLeftChild(N);
/* If it exists, update its parent pointer too */
if (RtlRightChild(P)) RtlParent(RtlRightChild(P)) = P;
/* Now make N the root, no need to worry about references */
N->Parent = N;
/* And make P its left child */
N->LeftChild = P;
P->Parent = N;
}
}
}
/* Return the root entry */
ASSERT(RtlIsRoot(N));
return N;
}
