Bool SplayFindLast(Tree *nodeReturn, SplayTree splay,
SplayTestNodeFunction testNode,
SplayTestTreeFunction testTree,
void *closureP, Size closureS)
{
SplayFindClosureStruct closureStruct;
Bool found;
AVER(nodeReturn != NULL);
AVERT(SplayTree, splay);
AVER(FUNCHECK(testNode));
AVER(FUNCHECK(testTree));
if (SplayTreeIsEmpty(splay) ||
!testTree(splay, SplayTreeRoot(splay), closureP, closureS))
return FALSE; /* no suitable nodes in tree */
closureStruct.p = closureP;
closureStruct.s = closureS;
closureStruct.testNode = testNode;
closureStruct.testTree = testTree;
closureStruct.splay = splay;
found = SplaySplay(splay, &closureStruct,
SplayFindLastCompare) == CompareEQUAL &&
closureStruct.found;
while (!found) {
Tree oldRoot, newRoot;
oldRoot = SplayTreeRoot(splay);
newRoot = TreeLeft(oldRoot);
if (newRoot == TreeEMPTY || !(*testTree)(splay, newRoot, closureP, closureS))
return FALSE; /* no suitable nodes in the rest of the tree */
/* Temporarily chop off the right half-tree, inclusive of root,
so that the search excludes any nodes we've seen already. */
SplayTreeSetRoot(splay, newRoot);
TreeSetLeft(oldRoot, TreeEMPTY);
found = SplaySplay(splay, &closureStruct,
SplayFindLastCompare) == CompareEQUAL &&
closureStruct.found;
/* Restore the right tree, then rotate right so that the node we
just splayed is at the root. Update both. */
newRoot = SplayTreeRoot(splay);
TreeSetLeft(oldRoot, newRoot);
SplayTreeSetRoot(splay, oldRoot);
TreeRotateRight(&splay->root);
splay->updateNode(splay, oldRoot);
splay->updateNode(splay, newRoot);
}
*nodeReturn = SplayTreeRoot(splay);
return TRUE;
}
static Tree SplayZigZig(Tree middle, Tree *rightFirstIO, Tree rightNext)
{
AVERT_CRITICAL(Tree, middle);
AVER_CRITICAL(rightFirstIO != NULL);
AVERT_CRITICAL(Tree, *rightFirstIO);
TreeSetLeft(*rightFirstIO, TreeRight(middle));
TreeSetRight(middle, *rightFirstIO);
TreeSetLeft(rightNext, middle);
*rightFirstIO = middle;
return TreeLeft(middle);
}
static Tree SplayZigZigRev(Tree middle, Tree *rightFirstIO)
{
Tree child;
AVERT_CRITICAL(Tree, middle);
AVER_CRITICAL(rightFirstIO != NULL);
AVERT_CRITICAL(Tree, *rightFirstIO);
child = TreeLeft(middle);
TreeSetLeft(middle, TreeLeft(*rightFirstIO));
TreeSetLeft(*rightFirstIO, TreeRight(middle));
TreeSetRight(middle, *rightFirstIO);
*rightFirstIO = middle;
return child;
}
static Tree SplayTreeSuccessor(SplayTree splay)
{
Tree oldRoot, newRoot;
AVERT(SplayTree, splay);
AVER(!SplayTreeIsEmpty(splay));
oldRoot = SplayTreeRoot(splay);
if (!TreeHasRight(oldRoot))
return TreeEMPTY; /* No successor */
/* temporarily chop off the left half-tree, inclusive of root */
SplayTreeSetRoot(splay, TreeRight(oldRoot));
TreeSetRight(oldRoot, TreeEMPTY);
(void)SplaySplay(splay, NULL, compareLess);
newRoot = SplayTreeRoot(splay);
AVER(newRoot != TreeEMPTY);
AVER(TreeLeft(newRoot) == TreeEMPTY);
TreeSetLeft(newRoot, oldRoot);
splay->updateNode(splay, oldRoot);
splay->updateNode(splay, newRoot);
return newRoot;
}
static Tree stepUpRight(Tree node, Tree *parentIO)
{
Tree parent = *parentIO;
Tree grandparent = TreeLeft(parent);
TreeSetLeft(parent, node);
*parentIO = grandparent;
return parent;
}
static Tree stepDownLeft(Tree node, Tree *parentIO)
{
Tree parent = *parentIO;
Tree child = TreeLeft(node);
TreeSetLeft(node, parent);
*parentIO = node;
return child;
}
static void SplayAssembleDown(SplayTree splay, SplayState state)
{
AVERT(SplayTree, splay);
AVER(state->middle != TreeEMPTY);
AVER(!SplayHasUpdate(splay));
if (state->left != TreeEMPTY) {
AVER_CRITICAL(state->leftLast != TreeEMPTY);
TreeSetRight(state->leftLast, TreeLeft(state->middle));
TreeSetLeft(state->middle, state->left);
}
if (state->right != TreeEMPTY) {
AVER_CRITICAL(state->rightFirst != TreeEMPTY);
TreeSetLeft(state->rightFirst, TreeRight(state->middle));
TreeSetRight(state->middle, state->right);
}
}
Bool SplayTreeInsert(SplayTree splay, Tree node)
{
Tree neighbour;
AVERT(SplayTree, splay);
AVERT(Tree, node);
AVER(TreeLeft(node) == TreeEMPTY);
AVER(TreeRight(node) == TreeEMPTY);
if (SplayTreeIsEmpty(splay)) {
SplayTreeSetRoot(splay, node);
return TRUE;
}
switch (SplaySplay(splay, splay->nodeKey(node), splay->compare)) {
default:
NOTREACHED;
/* fall through */
case CompareEQUAL: /* duplicate node */
return FALSE;
case CompareGREATER: /* left neighbour is at root */
neighbour = SplayTreeRoot(splay);
SplayTreeSetRoot(splay, node);
TreeSetRight(node, TreeRight(neighbour));
TreeSetLeft(node, neighbour);
TreeSetRight(neighbour, TreeEMPTY);
break;
case CompareLESS: /* right neighbour is at root */
neighbour = SplayTreeRoot(splay);
SplayTreeSetRoot(splay, node);
TreeSetLeft(node, TreeLeft(neighbour));
TreeSetRight(node, neighbour);
TreeSetLeft(neighbour, TreeEMPTY);
break;
}
splay->updateNode(splay, neighbour);
splay->updateNode(splay, node);
return TRUE;
}
static Tree SplayZagZag(Tree middle, Tree *leftLastIO, Tree leftPrev)
{
AVERT_CRITICAL(Tree, middle);
AVER_CRITICAL(leftLastIO != NULL);
AVERT_CRITICAL(Tree, *leftLastIO);
TreeSetRight(*leftLastIO, TreeLeft(middle));
TreeSetLeft(middle, *leftLastIO);
TreeSetRight(leftPrev, middle);
*leftLastIO = middle;
return TreeRight(middle);
}
static Tree SplayZagZagRev(Tree middle, Tree *leftLastIO)
{
Tree child;
AVERT_CRITICAL(Tree, middle);
AVER_CRITICAL(leftLastIO != NULL);
AVERT_CRITICAL(Tree, *leftLastIO);
child = TreeRight(middle);
TreeSetRight(middle, TreeRight(*leftLastIO));
TreeSetRight(*leftLastIO, TreeLeft(middle));
TreeSetLeft(middle, *leftLastIO);
*leftLastIO = middle;
return child;
}
static Tree SplayUpdateLeftSpine(SplayTree splay, Tree node, Tree child)
{
AVERT_CRITICAL(SplayTree, splay);
AVERT_CRITICAL(Tree, node);
AVERT_CRITICAL(Tree, child);
while(node != TreeEMPTY) {
Tree parent = TreeLeft(node);
TreeSetLeft(node, child); /* un-reverse pointer */
splay->updateNode(splay, node);
child = node;
node = parent;
}
return child;
}
void TreeRotateRight(Tree *treeIO) {
Tree tree, left;
AVER(treeIO != NULL);
tree = *treeIO;
AVERT(Tree, tree);
left = TreeLeft(tree);
AVERT(Tree, left);
TreeSetLeft(*treeIO, TreeRight(left));
TreeSetRight(left, *treeIO);
*treeIO = left;
}
void TreeRotateLeft(Tree *treeIO)
{
Tree tree, right;
AVER(treeIO != NULL);
tree = *treeIO;
AVERT(Tree, tree);
right = TreeRight(tree);
AVERT(Tree, right);
TreeSetRight(tree, TreeLeft(right));
TreeSetLeft(right, tree);
*treeIO = right;
}
static void SplayAssembleRev(SplayTree splay, SplayState state)
{
Tree left, right;
AVERT(SplayTree, splay);
AVER(state->middle != TreeEMPTY);
left = TreeLeft(state->middle);
left = SplayUpdateRightSpine(splay, state->leftLast, left);
TreeSetLeft(state->middle, left);
right = TreeRight(state->middle);
right = SplayUpdateLeftSpine(splay, state->rightFirst, right);
TreeSetRight(state->middle, right);
splay->updateNode(splay, state->middle);
}
Tree TreeReverseLeftSpine(Tree tree)
{
Tree node, parent;
AVERT(Tree, tree);
parent = TreeEMPTY;
node = tree;
while (node != TreeEMPTY) {
Tree child = TreeLeft(node);
TreeSetLeft(node, parent);
parent = node;
node = child;
}
return parent;
}
