static struct avl_node *avl_rotate_single(struct avl_node *root, int dir)
{
struct avl_node *save;
int rlh, rrh, slh;
/* Rotate */
save = root->link[!dir];
root->link[!dir] = save->link[dir];
if (root->link[!dir])
root->link[!dir]->up = root;
save->link[dir] = root;
if ( root )
root->up = save;
/* Update balance factors */
rlh = avl_height(root->link[0]);
rrh = avl_height(root->link[1]);
slh = avl_height(save->link[!dir]);
root->balance = avl_max(rlh, rrh) + 1;
save->balance = avl_max(slh, root->balance) + 1;
return save;
}
static node_t *
avl_single(node_t *root, int dir)
{
node_t *save = root->link[!dir];
int rlh, rrh, slh;
root->link[!dir] = save->link[dir];
save->link[dir] = root;
rlh = height(root->link[0]);
rrh = height(root->link[1]);
slh = height(save->link[!dir]);
BALANCE(root) = avl_max(rlh, rrh) + 1;
BALANCE(save) = avl_max(slh, BALANCE(root)) + 1;
return save;
}
extern int
avl_remove(node_t **rootaddr, PyObject *key)
{
node_t *root = *rootaddr;
int cmp_res;
if (root != NULL) {
node_t *it, *up[32];
int upd[32], top = 0;
it = root;
for (;;) {
if (it == NULL)
return 0;
cmp_res = ct_compare(KEY(it), key);
if (cmp_res == 0)
break;
upd[top] = (cmp_res < 0);
up[top++] = it;
it = it->link[upd[top - 1]];
}
if (it->link[0] == NULL ||
it->link[1] == NULL) {
int dir = it->link[0] == NULL;
if (top != 0)
up[top - 1]->link[upd[top - 1]] = it->link[dir];
else
root = it->link[dir];
ct_delete_node(it);
}
else {
node_t *heir = it->link[1];
upd[top] = 1;
up[top++] = it;
while ( heir->link[0] != NULL ) {
upd[top] = 0;
up[top++] = heir;
heir = heir->link[0];
}
ct_swap_data(it, heir);
up[top - 1]->link[up[top - 1] == it] = heir->link[1];
ct_delete_node(heir);
}
while (--top >= 0) {
int lh = height(up[top]->link[upd[top]]);
int rh = height(up[top]->link[!upd[top]]);
int max = avl_max(lh, rh);
BALANCE(up[top]) = max + 1;
if (lh - rh == -1)
break;
if (lh - rh <= -2) {
node_t *a = up[top]->link[!upd[top]]->link[upd[top]];
node_t *b = up[top]->link[!upd[top]]->link[!upd[top]];
if (height(a) <= height(b))
up[top] = avl_single(up[top], upd[top]);
else
up[top] = avl_double(up[top], upd[top]);
if (top != 0)
up[top - 1]->link[upd[top - 1]] = up[top];
else
root = up[0];
}
}
}
(*rootaddr) = root;
return 1;
}
extern int
avl_insert(node_t **rootaddr, PyObject *key, PyObject *value)
{
node_t *root = *rootaddr;
if (root == NULL) {
root = avl_new_node(key, value);
if (root == NULL)
return -1;
}
else {
node_t *it, *up[32];
int upd[32], top = 0;
int done = 0;
int cmp_res;
it = root;
for (;;) {
cmp_res = ct_compare(KEY(it), key);
if (cmp_res == 0) {
Py_XDECREF(VALUE(it));
VALUE(it) = value;
Py_INCREF(value);
return 0;
}
upd[top] = (cmp_res < 0);
up[top++] = it;
if (it->link[upd[top - 1]] == NULL)
break;
it = it->link[upd[top - 1]];
}
it->link[upd[top - 1]] = avl_new_node(key, value);
if (it->link[upd[top - 1]] == NULL)
return -1;
while (--top >= 0 && !done) {
int lh, rh, max;
cmp_res = ct_compare(KEY(up[top]), key);
lh = height(up[top]->link[upd[top]]);
rh = height(up[top]->link[!upd[top]]);
if (lh - rh == 0)
done = 1;
if (lh - rh >= 2) {
node_t *a = up[top]->link[upd[top]]->link[upd[top]];
node_t *b = up[top]->link[upd[top]]->link[!upd[top]];
if (height( a ) >= height( b ))
up[top] = avl_single(up[top], !upd[top]);
else
up[top] = avl_double(up[top], !upd[top]);
if (top != 0)
up[top - 1]->link[upd[top - 1]] = up[top];
else
root = up[0];
done = 1;
}
lh = height(up[top]->link[upd[top]]);
rh = height(up[top]->link[!upd[top]]);
max = avl_max(lh, rh);
BALANCE(up[top]) = max + 1;
}
}
(*rootaddr) = root;
return 1;
}
void *avl_remove(struct avl_tree *tree, void *key)
{
struct avl_node *it = tree->root;
struct avl_node *up[AVL_MAX_HEIGHT];
int upd[AVL_MAX_HEIGHT], top = 0, cmp;
paranoia(-500182, !it); // paranoia if not found
// while ((cmp = memcmp(it->key, key, tree->key_size)) ) {
while ((cmp = memcmp(it->key, key, tree->key_size)) || (it->link[0] && !memcmp(it->link[0]->key, key, tree->key_size))) {
// Push direction and node onto stack
upd[top] = (cmp < 0);
up[top] = it;
top++;
if (!(it = it->link[(cmp < 0)]))
return NULL;
}
// remember and return the found key. It might have been another one than intended
key = it->key;
// Remove the node:
if (!(it->link[0] && it->link[1])) { // at least one child is NULL:
// Which child is not null?
int dir = !(it->link[0]);
/* Fix parent */
if (top) {
up[top - 1]->link[upd[top - 1]] = it->link[dir];
if (it->link[dir])
it->link[dir]->up = up[top - 1];
} else {
tree->root = it->link[dir];
if (tree->root)
tree->root->up = NULL;
}
debugFree(it, 1327);
} else { // both childs NOT NULL:
// Find the inorder successor
struct avl_node *heir = it->link[1];
// Save the path
upd[top] = 1;
up[top] = it;
top++;
while (heir->link[0]) {
upd[top] = 0;
up[top] = heir;
top++;
heir = heir->link[0];
}
// Swap data
it->key = heir->key;
// Unlink successor and fix parent
up[top - 1]->link[ (up[top - 1] == it) ] = heir->link[1];
if ( heir->link[1])
heir->link[1]->up = up[top - 1];
debugFree(heir, 2327);
}
// Walk back up the search path
while (--top >= 0) {
int lh = avl_height(up[top]->link[upd[top]]);
int rh = avl_height(up[top]->link[!upd[top]]);
int max = avl_max(lh, rh);
/* Update balance factors */
up[top]->balance = max + 1;
// Terminate or re-balance as necessary:
if (lh - rh >= 0) // re-balance upper path...
continue;
if (lh - rh == -1) // balance for upper path unchanged!
break;
if (!(up[top]) || !(up[top]->link[!upd[top]])) {
dbgf(DBGL_SYS, DBGT_ERR, "up(top) %p link %p lh %d rh %d",
(void*)(up[top]), (void*)((up[top]) ? (up[top]->link[!upd[top]]) : NULL), lh, rh);
paranoia(-500187, (!(up[top])));
paranoia(-500188, (!(up[top]->link[!upd[top]])));
}
/*
paranoia(-500183, (lh - rh <= -3) );
paranoia(-500185, (lh - rh == 2) );
paranoia(-500186, (lh - rh >= 3) );
*/
// if (lh - rh <= -2): rebalance here and upper path
struct avl_node *a = up[top]->link[!upd[top]]->link[upd[top]];
struct avl_node *b = up[top]->link[!upd[top]]->link[!upd[top]];
if (avl_height(a) <= avl_height(b))
up[top] = avl_rotate_single(up[top], upd[top]);
else
up[top] = avl_rotate_double(up[top], upd[top]);
// Fix parent:
if (top) {
up[top - 1]->link[upd[top - 1]] = up[top];
up[top]->up = up[top - 1];
} else {
tree->root = up[0];
tree->root->up = NULL;
}
}
return key;
}
void avl_insert(struct avl_tree *tree, void *key) {
if (tree->root) {
struct avl_node *it = tree->root;
struct avl_node *up[AVL_MAX_HEIGHT];
int upd[AVL_MAX_HEIGHT], top = 0;
int done = 0;
/* Search for an empty link, save the path */
for (;;) {
/* Push direction and node onto stack */
// upd[top] = memcmp(it->key, key, tree->key_size) < 0;
upd[top] = memcmp(it->key, key, tree->key_size) <= 0;
up[top++] = it;
if (it->link[upd[top - 1]] == NULL)
break;
it = it->link[upd[top - 1]];
}
/* Insert a new node at the bottom of the tree */
it->link[upd[top - 1]] = avl_create_node(key);
it->link[upd[top - 1]]->up = it;
paranoia(-500178, (it->link[upd[top - 1]] == NULL));
/* Walk back up the search path */
while (--top >= 0 && !done) {
int lh, rh, max;
lh = avl_height(up[top]->link[upd[top]]);
rh = avl_height(up[top]->link[!upd[top]]);
/* Terminate or rebalance as necessary */
if (lh - rh == 0)
done = 1;
if (lh - rh >= 2) {
struct avl_node *a = up[top]->link[upd[top]]->link[upd[top]];
struct avl_node *b = up[top]->link[upd[top]]->link[!upd[top]];
if (avl_height(a) >= avl_height(b))
up[top] = avl_rotate_single(up[top], !upd[top]);
else
up[top] = avl_rotate_double(up[top], !upd[top]);
/* Fix parent */
if (top != 0) {
up[top - 1]->link[upd[top - 1]] = up[top];
up[top]->up = up[top - 1];
} else {
tree->root = up[0];
up[0]->up = NULL;
}
done = 1;
}
/* Update balance factors */
lh = avl_height(up[top]->link[upd[top]]);
rh = avl_height(up[top]->link[!upd[top]]);
max = avl_max(lh, rh);
up[top]->balance = max + 1;
}
} else {
tree->root = avl_create_node(key);
paranoia( -500179, (tree->root==NULL));
}
return;
}
