toaruos/kernel/core/tree.c
2011-11-29 07:01:36 -06:00

118 lines
2.9 KiB
C

/* vim: tabstop=4 shiftwidth=4 noexpandtab
*
* General-purpose tree implementation
*/
#include <system.h>
#include <list.h>
#include <tree.h>
tree_t * tree_create() {
tree_t * out = malloc(sizeof(tree_t));
out->nodes = 0;
out->root = NULL;
return out;
}
void tree_set_root(tree_t * tree, void * value) {
tree_node_t * root = tree_node_create(value);
tree->root = root;
tree->nodes = 1;
}
void tree_node_destroy(tree_node_t * node) {
foreach(child, node->children) {
tree_node_destroy((tree_node_t *)child->value);
}
free(node->value);
}
void tree_destroy(tree_t * tree) {
if (tree->root) {
tree_node_destroy(tree->root);
}
}
void tree_node_free(tree_node_t * node) {
if (!node) return;
foreach(child, node->children) {
tree_node_free(child->value);
}
free(node);
}
void tree_free(tree_t * tree) {
tree_node_free(tree->root);
}
tree_node_t * tree_node_create(void * value) {
tree_node_t * out = malloc(sizeof(tree_node_t));
out->value = value;
out->children = list_create();
out->parent = NULL;
return out;
}
void tree_node_insert_child_node(tree_t * tree, tree_node_t * parent, tree_node_t * node) {
list_insert(parent->children, node);
node->parent = parent;
tree->nodes++;
}
tree_node_t * tree_node_insert_child(tree_t * tree, tree_node_t * parent, void * value) {
tree_node_t * out = tree_node_create(value);
tree_node_insert_child_node(tree, parent, out);
return out;
}
tree_node_t * tree_node_find_parent(tree_node_t * haystack, tree_node_t * needle) {
tree_node_t * found = NULL;
foreach(child, haystack->children) {
if (child->value == needle) {
return haystack;
}
found = tree_node_find_parent((tree_node_t *)child->value, needle);
if (found) {
break;
}
}
return found;
}
tree_node_t * tree_find_parent(tree_t * tree, tree_node_t * node) {
if (!tree->root) return NULL;
return tree_node_find_parent(tree->root, node);
}
size_t tree_count_children(tree_node_t * node) {
if (!node) return 0;
if (!node->children) return 0;
size_t out = node->children->length;
foreach(child, node->children) {
out += tree_count_children((tree_node_t *)child->value);
}
return out;
}
void tree_node_parent_remove(tree_t * tree, tree_node_t * parent, tree_node_t * node) {
tree->nodes -= tree_count_children(node) + 1;
list_delete(parent->children, list_find(parent->children, node));
tree_node_free(node);
}
void tree_node_remove(tree_t * tree, tree_node_t * node) {
tree_node_t * parent = node->parent;
/* We can not directly remove the root node, try constructing a new tree instead. */
if (!parent) return;
tree_node_parent_remove(tree, parent, node);
}
void tree_remove(tree_t * tree, tree_node_t * node) {
tree_node_t * parent = node->parent;
if (!parent) return;
/* Remove this node and move its children into its parent's list of children */
tree->nodes--;
list_delete(parent->children, list_find(parent->children, node));
list_merge(parent->children, node->children);
free(node);
}