/* Restore the reb-black properties after a delete */
static void rb_delete_fix(struct rbnode **rootp, struct rbnode *x) {
struct rbnode *w;
while (x!=*rootp && x->colour==BLACK) {
if (x==x->up->left) {
w=x->up->right;
if (w->colour==RED) {
w->colour=BLACK;
x->up->colour=RED;
rb_left_rotate(rootp, x->up);
w=x->up->right;
}
if (w->left->colour==BLACK && w->right->colour==BLACK) {
w->colour=RED;
x=x->up;
} else {
if (w->right->colour == BLACK) {
w->left->colour=BLACK;
w->colour=RED;
rb_right_rotate(rootp, w);
w=x->up->right;
}
w->colour=x->up->colour;
x->up->colour = BLACK;
w->right->colour = BLACK;
rb_left_rotate(rootp, x->up);
x=*rootp;
}
} else {
w=x->up->left;
if (w->colour==RED) {
w->colour=BLACK;
x->up->colour=RED;
rb_right_rotate(rootp, x->up);
w=x->up->left;
}
if (w->right->colour==BLACK && w->left->colour==BLACK) {
w->colour=RED;
x=x->up;
} else {
if (w->left->colour == BLACK) {
w->right->colour=BLACK;
w->colour=RED;
rb_left_rotate(rootp, w);
w=x->up->left;
}
w->colour=x->up->colour;
x->up->colour = BLACK;
w->left->colour = BLACK;
rb_right_rotate(rootp, x->up);
x=*rootp;
}
}
}
x->colour=BLACK;
}
static void rb_insert_fixup(struct rb_node **root, struct rb_node *n)
{
struct rb_node *uncle;
while (n->p->c == 'R') {
if (n->p == n->p->p->lc) {
uncle = n->p->p->rc;
if (uncle->c == 'R') { /* case 1 */
n->p->c = 'B';
uncle->c = 'B';
n->p->p->c = 'R';
/* pull n up to its grandpa */
n = n->p->p;
}
else {
if (n == n->p->rc) { /* case 2 */
/* make sure n's color is RED */
n = n->p;
rb_left_rotate(root, n);
}
n->p->c = 'B'; /* case 3 */
n->p->p->c = 'R';
rb_right_rotate(root, n->p->p);
}
}
else {
uncle = n->p->p->lc;
if (uncle->c == 'R') { /* case 1 */
n->p->c = 'B';
uncle->c = 'B';
n->p->p->c = 'R';
/* pull n up to its grandpa */
n = n->p->p;
}
else {
if (n == n->p->lc) { /* case 2 */
/* make sure n's color is RED */
n = n->p;
rb_right_rotate(root, n);
}
n->p->c = 'B'; /* case 3 */
n->p->p->c = 'R';
rb_left_rotate(root, n->p->p);
}
}
}
(*root)->c = 'B';
}
static void rb_insert_fixup (struct rb_node **root, struct rb_node *z)
{
while (z->parent->color == RB_RED)
if (z->parent == z->parent->parent->left) {
struct rb_node *y = z->parent->parent->right;
if (y->color == RB_RED) {
z->parent->color = RB_BLACK;
y->color = RB_BLACK;
z->parent->parent->color = RB_RED;
z = z->parent->parent;
}
else {
if (z == z->parent->right) {
z = z->parent;
rb_left_rotate (root, z);
}
z->parent->color = RB_BLACK;
z->parent->parent->color = RB_RED;
rb_right_rotate (root, z->parent->parent);
}
}
else {
struct rb_node *y = z->parent->parent->left;
if (y->color == RB_RED) {
z->parent->color = RB_BLACK;
y->color = RB_BLACK;
z->parent->parent->color = RB_RED;
z = z->parent->parent;
}
else {
if (z == z->parent->left) {
z = z->parent;
rb_right_rotate (root, z);
}
z->parent->color = RB_BLACK;
z->parent->parent->color = RB_RED;
rb_left_rotate (root, z->parent->parent);
}
}
(*root)->color = RB_BLACK;
}
static rb_node_t *rb_insert_fixup(rb_tree *tree, rb_node_t *z) {
while (z->parent->color == RED) {
if (z->parent == z->parent->parent->left) {
rb_node_t *y = z->parent->parent->right;
if (y->color == RED) {
z->parent->color = BLACK;
y->color = BLACK;
z->parent->parent->color = RED;
z = z->parent->parent;
} else {
if (z == z->parent->right) {
z = z->parent;
rb_left_rotate(tree, z);
}
z->parent->color = BLACK;
z->parent->parent->color = RED;
rb_right_rotate(tree, z->parent->parent);
}
} else {
rb_node_t *y = z->parent->parent->left;
if (y->color == RED) {
z->parent->color = BLACK;
y->color = BLACK;
z->parent->parent->color = RED;
z = z->parent->parent;
} else {
if (z == z->parent->left) {
z = z->parent;
rb_right_rotate(tree, z);
}
z->parent->color = BLACK;
z->parent->parent->color = RED;
rb_left_rotate(tree, z->parent->parent);
}
}
}
tree->root->color = BLACK;
return tree->root;
}
static rb_node_t *rb_delete_fixup(rb_tree *tree, rb_node_t *x) {
rb_node_t *w;
while (x != tree->root && x->color == BLACK) {
if (x == x->parent->left) {
w = x->parent->right;
if (w->color == RED) {
w->color = BLACK;
x->parent->color = RED;
rb_left_rotate(tree, x->parent);
w = x->parent->right;
}
if (w->left->color == BLACK && w->right->color == BLACK) {
w->color = RED;
x = x->parent;
} else {
if (w->right->color == BLACK) {
w->left->color = BLACK;
w->color = RED;
rb_right_rotate(tree, w);
w = x->parent->right;
}
w->color = x->parent->color;
x->parent->color = BLACK;
w->right->color = BLACK;
rb_left_rotate(tree, x->parent);
x = tree->root;
}
} else {
w = x->parent->left;
if (w->color == RED) {
w->color = BLACK;
x->parent->color = RED;
rb_right_rotate(tree, x->parent);
w = x->parent->left;
}
if (w->left->color == BLACK && w->right->color == BLACK) {
w->color = RED;
x = x->parent;
} else {
if (w->left->color == BLACK) {
w->right->color = BLACK;
w->color = RED;
rb_left_rotate(tree, w);
w = x->parent->left;
}
w->color = x->parent->color;
x->parent->color = BLACK;
w->left->color = BLACK;
rb_right_rotate(tree, x->parent);
x = tree->root;
}
}
}
x->color = BLACK;
return tree->root;
}
/* Search for and if not found and insert is true, will add a new
** node in. Returns a pointer to the new node, or the node found
*/
int rbinsert(const void *key, const void * high, void *object,struct rbtree *rbinfo) {
struct rbnode *x,*y,*z, *tmp;
const void *max;
int found=0;
y=RBNULL; /* points to the parent of x */
x=rbinfo->rb_root;
/* walk x down the tree */
while(x!=RBNULL && found==0) {
y=x;
/* printf("key=%s, x->key=%s\n", key, x->key); */
if (key<x->key)
x=x->left;
else if (key>x->key)
x=x->right;
else
found=1;
}
if (found)
return RB_FALSE;
if ((z=rb_alloc())==NULL) {
/* Whoops, no memory */
return RB_FALSE;
}
z->object=object;
z->high=high;
z->key=key;
z->max=high;
z->up=y;
tmp=y;
max=high;
while(tmp!=RBNULL) {
if (max>tmp->max)
tmp->max=max;
else
max=tmp->max;
tmp=tmp->up;
}
if (y==RBNULL) {
rbinfo->rb_root=z;
} else {
if (z->key<y->key)
y->left=z;
else
y->right=z;
}
z->left=RBNULL;
z->right=RBNULL;
/* colour this new node red */
z->colour=RED;
/* Having added a red node, we must now walk back up the tree balancing
** it, by a series of rotations and changing of colours
*/
x=z;
/* While we are not at the top and our parent node is red
** N.B. Since the root node is garanteed black, then we
** are also going to stop if we are the child of the root
*/
while(x != rbinfo->rb_root && (x->up->colour == RED)) {
/* if our parent is on the left side of our grandparent */
if (x->up == x->up->up->left) {
/* get the right side of our grandparent (uncle?) */
y=x->up->up->right;
if (y->colour == RED) {
/* make our parent black */
x->up->colour = BLACK;
/* make our uncle black */
y->colour = BLACK;
/* make our grandparent red */
x->up->up->colour = RED;
/* now consider our grandparent */
x=x->up->up;
} else {
/* if we are on the right side of our parent */
if (x == x->up->right) {
/* Move up to our parent */
x=x->up;
rb_left_rotate(&rbinfo->rb_root, x);
}
/* make our parent black */
x->up->colour = BLACK;
/* make our grandparent red */
x->up->up->colour = RED;
/* right rotate our grandparent */
rb_right_rotate(&rbinfo->rb_root, x->up->up);
}
} else {
/* everything here is the same as above, but
** exchanging left for right
*/
y=x->up->up->left;
if (y->colour == RED) {
x->up->colour = BLACK;
y->colour = BLACK;
x->up->up->colour = RED;
x=x->up->up;
} else {
if (x == x->up->left) {
x=x->up;
rb_right_rotate(&rbinfo->rb_root, x);
}
x->up->colour = BLACK;
x->up->up->colour = RED;
rb_left_rotate(&rbinfo->rb_root, x->up->up);
}
}
}
/* Set the root node black */
(rbinfo->rb_root)->colour = BLACK;
return RB_TRUE;
}
static void rb_delete_fixup (struct rb_node **root, struct rb_node *x,
struct rb_node *parent)
{
struct rb_node *w;
while (x != *root && x->color == RB_BLACK) {
if (x == parent->left) {
w = parent->right;
if (w->color == RB_RED) {
w->color = RB_BLACK;
parent->color = RB_RED;
rb_left_rotate (root, parent);
w = parent->right;
}
if (w->left->color == RB_BLACK
&& w->right->color == RB_BLACK) {
w->color = RB_RED;
x = parent;
parent = x->parent;
}
else {
if (w->right->color == RB_BLACK) {
w->left->color = RB_BLACK;
w->color = RB_RED;
rb_right_rotate (root, w);
w = parent->right;
}
w->color = parent->color;
parent->color = RB_BLACK;
w->right->color = RB_BLACK;
rb_left_rotate (root, parent);
x = *root;
}
}
else {
w = parent->left;
if (w->color == RB_RED) {
w->color = RB_BLACK;
parent->color = RB_RED;
rb_right_rotate (root, parent);
w = parent->left;
}
if (w->right->color == RB_BLACK
&& w->left->color == RB_BLACK) {
w->color = RB_RED;
x = parent;
parent = x->parent;
}
else {
if (w->left->color == RB_BLACK) {
w->right->color = RB_BLACK;
w->color = RB_RED;
rb_left_rotate (root, w);
w = parent->left;
}
w->color = parent->color;
parent->color = RB_BLACK;
w->left->color = RB_BLACK;
rb_right_rotate (root, parent);
x = *root;
}
}
}
x->color = RB_BLACK;
}
static struct rb_node *rb_delete_fixup(struct rb_node **root, struct rb_node *n)
{
struct rb_node *t;
while (n != *root && n->c == 'B') {
if (n == n->p->lc) {
t = n->p->rc;
if (t->c == 'R') { /* case 1 */
t->c = 'B';
n->p->c = 'R';
rb_left_rotate(root, n->p);
t = n->p->rc;
}
if (t->lc->c == 'B' && t->rc->c == 'B') { /* case 2 */
t->c = 'R';
n = n->p;
}
else {
if (t->rc->c == 'B') { /* case 3 */
t->lc->c = 'B';
t->c = 'R';
rb_right_rotate(root, t);
t = n->p->rc;
}
t->c = n->p->c;
n->p->c = 'B';
t->rc->c = 'B';
rb_left_rotate(root, n->p);
}
}
else { /* n == n->p->rc */
t = n->p->lc;
if (t->c == 'R') { /* case 1 */
t->c = 'B';
n->p->c = 'R';
rb_right_rotate(root, n->p);
t = n->p->lc;
}
if (t->lc->c == 'B' && t->rc->c == 'B') { /* case 2 */
t->c = 'R';
n = n->p;
}
else {
if (t->lc->c == 'B') { /* case 3 */
t->rc->c = 'B';
t->c = 'R';
rb_left_rotate(root, t);
t = n->p->lc;
}
t->c = n->p->c;
n->p->c = 'B';
t->lc->c = 'B';
rb_right_rotate(root, n->p);
}
}
}
/* n is root now */
n->c = 'B';
return *root;
}