void * getelt_rbtree ( const RBTREE tree, const void * key){
assert(NULL!=tree);
assert(NULL!=key);
RBNODE node = search_rbtree(tree,key);
if (NULL!=node){ return node->value;}
return NULL;
}
rt_connection* get_connection(connection_table* ct, uint16_t hid, uint32_t window){
rt_connection *rt = search_rbtree(*ct, &hid);
if(rt)
return rt;
debug(I, "Connection with handler %d not found. Creating it...\n", hid);
rt = mkrtconnection(window, hid);
rb_tree_insert(ct, rt);
return rt;
}
/* Need to decide what to do about memory for keys.
* Possible memory leak at moment. */
void * removeelt_rbtree (RBTREE tree, const void * key){
RBNODE phantom = NULL;
void * retval = NULL;
assert(NULL!=tree);
assert(NULL!=key);
RBNODE delnode = search_rbtree(tree,key);
if (NULL==delnode){ return retval;} /* Nothing to delete */
retval = delnode->value;
tree->freekey(delnode->key);
/* Node has two non-null children. Transform so not case */
if (NULL!=delnode->right && NULL!=delnode->left){
RBNODE leftmost = minnode_rbtree_sub(delnode->right);
delnode->key = leftmost->key;
delnode->value = leftmost->value;
delnode = leftmost;
}
/* delnode now has at most one child */
enum rbcolour delcol = delnode->colour;
RBNODE child = (NULL==delnode->right)?delnode->left:delnode->right;
if ( NULL==child){
child = create_rbnode(black); /* "Phantom node" */
phantom = child;
}
/* Replace node with child */
if (NULL!=delnode->parent){
if (delnode->parent->left==delnode) delnode->parent->left = child;
else if (delnode->parent->right==delnode) delnode->parent->right = child;
else abort();
} else {
tree->root = child;
}
child->parent = delnode->parent;
free(delnode);
if(red==delcol){ goto remove_end;}
/* Deleted node was black */
if (red==colour_rbnode(child)){ child->colour = black; goto remove_end;}
case1:
/* Case 1 */
if ( NULL==child->parent){ /* New root */
tree->root = child;
goto remove_end;
}
/* Case 2 */
RBNODE sibling = sibling_rbnode(child);
if ( red==colour_rbnode(sibling)){
child->parent->colour = red;
sibling->colour = black;
if ( child == child->parent->left) rotate_left_rbtree (child->parent,tree);
else rotate_right_rbtree(child->parent,tree);
}
sibling = sibling_rbnode(child);
assert(sibling->colour==black);
/* Case 3 */
if ( black== child->parent->colour
&& black==colour_rbnode(sibling->left) && black==colour_rbnode(sibling->right)){
sibling->colour = red;
child = child->parent;
goto case1;
}
assert(sibling->colour==black);
/* Case 4 */
if ( red == child->parent->colour
&& black==colour_rbnode(sibling->left) && black==colour_rbnode(sibling->right)){
sibling->colour = red;
child->parent->colour = black;
goto remove_end;
}
assert(sibling->colour == black);
/* Case 5 */
if ( child==child->parent->left
&& red==colour_rbnode(sibling->left) && black==colour_rbnode(sibling->right)){
sibling->colour = red;
sibling->left->colour = black;
rotate_right_rbtree(sibling,tree);
} else if ( child==child->parent->right
&& black==colour_rbnode(sibling->left) && red==colour_rbnode(sibling->right)){
sibling->colour = red;
sibling->right->colour = black;
rotate_left_rbtree(sibling,tree);
}
sibling = sibling_rbnode(child);
/* Case 6 */
sibling->colour = child->parent->colour;
child->parent->colour = black;
if ( child == child->parent->left){
sibling->right->colour = black;
rotate_left_rbtree(child->parent,tree);
} else {
sibling->left->colour = black;
rotate_right_rbtree(child->parent,tree);
}
remove_end:
/* Delelte phantom node */
if ( phantom ){
if ( NULL!=phantom->parent){
if (phantom->parent->left == phantom) phantom->parent->left = NULL;
else if (phantom->parent->right == phantom) phantom->parent->right = NULL;
else abort();
}
if(tree->root==phantom){tree->root = NULL;}
free(phantom);
}
return retval;
}
bool member_rbtree ( const RBTREE tree, const void * key){
RBNODE node = search_rbtree (tree,key);
if ( NULL==node) return false;
return true;
}
