toolkit: comparison ucx/tree.c

-:38cb8e3992e8
+:ce13a778654a
 * POSSIBILITY OF SUCH DAMAGE.
 */
 #include "cx/tree.h"
+#include "cx/array_list.h"
 #include <assert.h>
-#define CX_TREE_PTR(cur, off) (*(void**)(((char*)(cur))+(off)))
 #define CX_TREE_PTR(cur, off) (*(void**)(((char*)(cur))+(off)))
 #define tree_parent(node) CX_TREE_PTR(node, loc_parent)
 #define tree_children(node) CX_TREE_PTR(node, loc_children)
+#define tree_last_child(node) CX_TREE_PTR(node, loc_last_child)
 #define tree_prev(node) CX_TREE_PTR(node, loc_prev)
 #define tree_next(node) CX_TREE_PTR(node, loc_next)
+#define cx_tree_ptr_locations \
+loc_parent, loc_children, loc_last_child, loc_prev, loc_next
+static void cx_tree_zero_pointers(
+void *node,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+) {
+tree_parent(node) = NULL;
+tree_prev(node) = NULL;
+tree_next(node) = NULL;
+tree_children(node) = NULL;
+if (loc_last_child >= 0) {
+tree_last_child(node) = NULL;
+}
+}
 void cx_tree_link(
 void *restrict parent,
 void *restrict node,
 ptrdiff_t loc_parent,
 ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
 ptrdiff_t loc_prev,
 ptrdiff_t loc_next
 ) {
 void *current_parent = tree_parent(node);
 if (current_parent == parent) return;
 if (current_parent != NULL) {
-cx_tree_unlink(node, loc_parent, loc_children,
+cx_tree_unlink(node, cx_tree_ptr_locations);
-loc_prev, loc_next);
 }
 if (tree_children(parent) == NULL) {
 tree_children(parent) = node;
-} else {
+if (loc_last_child >= 0) {
-void *children = tree_children(parent);
+tree_last_child(parent) = node;
-tree_prev(children) = node;
+}
-tree_next(node) = children;
+} else {
-tree_children(parent) = node;
+if (loc_last_child >= 0) {
+void *child = tree_last_child(parent);
+tree_prev(node) = child;
+tree_next(child) = node;
+tree_last_child(parent) = node;
+} else {
+void *child = tree_children(parent);
+void *next;
+while ((next = tree_next(child)) != NULL) {
+child = next;
+}
+tree_prev(node) = child;
+tree_next(child) = node;
+}
 }
 tree_parent(node) = parent;
 }
 void cx_tree_unlink(
 void *node,
 ptrdiff_t loc_parent,
 ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
 ptrdiff_t loc_prev,
 ptrdiff_t loc_next
 ) {
 if (tree_parent(node) == NULL) return;
 void *left = tree_prev(node);
 void *right = tree_next(node);
-assert(left == NULL || tree_children(tree_parent(node)) != node);
+void *parent = tree_parent(node);
+assert(left == NULL || tree_children(parent) != node);
+assert(right == NULL || loc_last_child < 0 ||
+tree_last_child(parent) != node);
 if (left == NULL) {
-tree_children(tree_parent(node)) = right;
+tree_children(parent) = right;
 } else {
 tree_next(left) = right;
 }
-if (right != NULL) tree_prev(right) = left;
+if (right == NULL) {
+if (loc_last_child >= 0) {
+tree_last_child(parent) = left;
+}
+} else {
+tree_prev(right) = left;
+}
 tree_parent(node) = NULL;
 tree_prev(node) = NULL;
 tree_next(node) = NULL;
 }
+int cx_tree_search(
+const void *root,
+const void *node,
+cx_tree_search_func sfunc,
+void **result,
+ptrdiff_t loc_children,
+ptrdiff_t loc_next
+) {
+int ret;
+*result = NULL;
+// shortcut: compare root before doing anything else
+ret = sfunc(root, node);
+if (ret < 0) {
+return ret;
+} else if (ret == 0 || tree_children(root) == NULL) {
+*result = (void*)root;
+return ret;
+}
+// create a working stack
+CX_ARRAY_DECLARE(const void *, work);
+cx_array_initialize(work, 32);
+// add the children of root to the working stack
+{
+void *c = tree_children(root);
+while (c != NULL) {
+cx_array_simple_add(work, c);
+c = tree_next(c);
+}
+}
+// remember a candidate for adding the data
+// also remember the exact return code from sfunc
+void *candidate = (void *) root;
+int ret_candidate = ret;
+// process the working stack
+while (work_size > 0) {
+// pop element
+const void *elem = work[--work_size];
+// apply the search function
+ret = sfunc(elem, node);
+if (ret == 0) {
+// if found, exit the search
+*result = (void *) elem;
+work_size = 0;
+break;
+} else if (ret > 0) {
+// if children might contain the data, add them to the stack
+void *c = tree_children(elem);
+while (c != NULL) {
+cx_array_simple_add(work, c);
+c = tree_next(c);
+}
+// remember this node in case no child is suitable
+if (ret < ret_candidate) {
+candidate = (void *) elem;
+ret_candidate = ret;
+}
+}
+}
+// not found, but was there a candidate?
+if (ret != 0 && candidate != NULL) {
+ret = ret_candidate;
+*result = candidate;
+}
+// free the working queue and return
+free(work);
+return ret;
+}
+int cx_tree_search_data(
+const void *root,
+const void *data,
+cx_tree_search_data_func sfunc,
+void **result,
+ptrdiff_t loc_children,
+ptrdiff_t loc_next
+) {
+// it is basically the same implementation
+return cx_tree_search(
+root, data,
+(cx_tree_search_func) sfunc,
+result,
+loc_children, loc_next);
+}
+static bool cx_tree_iter_valid(const void *it) {
+const struct cx_tree_iterator_s *iter = it;
+return iter->node != NULL;
+}
+static void *cx_tree_iter_current(const void *it) {
+const struct cx_tree_iterator_s *iter = it;
+return iter->node;
+}
+static void cx_tree_iter_next(void *it) {
+struct cx_tree_iterator_s *iter = it;
+ptrdiff_t const loc_next = iter->loc_next;
+ptrdiff_t const loc_children = iter->loc_children;
+// protect us from misuse
+if (!iter->base.valid(iter)) return;
+void *children;
+// check if we are currently exiting or entering nodes
+if (iter->exiting) {
+children = NULL;
+// skipping on exit is pointless, just clear the flag
+iter->skip = false;
+} else {
+if (iter->skip) {
+// skip flag is set, pretend that there are no children
+iter->skip = false;
+children = NULL;
+} else {
+// try to enter the children (if any)
+children = tree_children(iter->node);
+}
+}
+if (children == NULL) {
+// search for the next node
+void *next;
+cx_tree_iter_search_next:
+// check if there is a sibling
+if (iter->exiting) {
+next = iter->node_next;
+} else {
+next = tree_next(iter->node);
+iter->node_next = next;
+}
+if (next == NULL) {
+// no sibling, we are done with this node and exit
+if (iter->visit_on_exit && !iter->exiting) {
+// iter is supposed to visit the node again
+iter->exiting = true;
+} else {
+iter->exiting = false;
+if (iter->depth == 1) {
+// there is no parent - we have iterated the entire tree
+// invalidate the iterator and free the node stack
+iter->node = iter->node_next = NULL;
+iter->stack_capacity = iter->depth = 0;
+free(iter->stack);
+iter->stack = NULL;
+} else {
+// the parent node can be obtained from the top of stack
+// this way we can avoid the loc_parent in the iterator
+iter->depth--;
+iter->node = iter->stack[iter->depth - 1];
+// retry with the parent node to find a sibling
+goto cx_tree_iter_search_next;
+}
+}
+} else {
+if (iter->visit_on_exit && !iter->exiting) {
+// iter is supposed to visit the node again
+iter->exiting = true;
+} else {
+iter->exiting = false;
+// move to the sibling
+iter->counter++;
+iter->node = next;
+// new top of stack is the sibling
+iter->stack[iter->depth - 1] = next;
+}
+}
+} else {
+// node has children, push the first child onto the stack and enter it
+cx_array_simple_add(iter->stack, children);
+iter->node = children;
+iter->counter++;
+}
+}
+CxTreeIterator cx_tree_iterator(
+void *root,
+bool visit_on_exit,
+ptrdiff_t loc_children,
+ptrdiff_t loc_next
+) {
+CxTreeIterator iter;
+iter.loc_children = loc_children;
+iter.loc_next = loc_next;
+iter.visit_on_exit = visit_on_exit;
+// initialize members
+iter.node_next = NULL;
+iter.exiting = false;
+iter.skip = false;
+// assign base iterator functions
+iter.base.mutating = false;
+iter.base.remove = false;
+iter.base.current_impl = NULL;
+iter.base.valid = cx_tree_iter_valid;
+iter.base.next = cx_tree_iter_next;
+iter.base.current = cx_tree_iter_current;
+// visit the root node
+iter.node = root;
+if (root != NULL) {
+iter.stack_capacity = 16;
+iter.stack = malloc(sizeof(void *) * 16);
+iter.stack[0] = root;
+iter.counter = 1;
+iter.depth = 1;
+} else {
+iter.stack_capacity = 0;
+iter.stack = NULL;
+iter.counter = 0;
+iter.depth = 0;
+}
+return iter;
+}
+static bool cx_tree_visitor_valid(const void *it) {
+const struct cx_tree_visitor_s *iter = it;
+return iter->node != NULL;
+}
+static void *cx_tree_visitor_current(const void *it) {
+const struct cx_tree_visitor_s *iter = it;
+return iter->node;
+}
+__attribute__((__nonnull__))
+static void cx_tree_visitor_enqueue_siblings(
+struct cx_tree_visitor_s *iter, void *node, ptrdiff_t loc_next) {
+node = tree_next(node);
+while (node != NULL) {
+struct cx_tree_visitor_queue_s *q;
+q = malloc(sizeof(struct cx_tree_visitor_queue_s));
+q->depth = iter->queue_last->depth;
+q->node = node;
+iter->queue_last->next = q;
+iter->queue_last = q;
+node = tree_next(node);
+}
+iter->queue_last->next = NULL;
+}
+static void cx_tree_visitor_next(void *it) {
+struct cx_tree_visitor_s *iter = it;
+// protect us from misuse
+if (!iter->base.valid(iter)) return;
+ptrdiff_t const loc_next = iter->loc_next;
+ptrdiff_t const loc_children = iter->loc_children;
+// add the children of the current node to the queue
+// unless the skip flag is set
+void *children;
+if (iter->skip) {
+iter->skip = false;
+children = NULL;
+} else {
+children = tree_children(iter->node);
+}
+if (children != NULL) {
+struct cx_tree_visitor_queue_s *q;
+q = malloc(sizeof(struct cx_tree_visitor_queue_s));
+q->depth = iter->depth + 1;
+q->node = children;
+if (iter->queue_last == NULL) {
+assert(iter->queue_next == NULL);
+iter->queue_next = q;
+} else {
+iter->queue_last->next = q;
+}
+iter->queue_last = q;
+cx_tree_visitor_enqueue_siblings(iter, children, loc_next);
+}
+// check if there is a next node
+if (iter->queue_next == NULL) {
+iter->node = NULL;
+return;
+}
+// dequeue the next node
+iter->node = iter->queue_next->node;
+iter->depth = iter->queue_next->depth;
+{
+struct cx_tree_visitor_queue_s *q = iter->queue_next;
+iter->queue_next = q->next;
+if (iter->queue_next == NULL) {
+assert(iter->queue_last == q);
+iter->queue_last = NULL;
+}
+free(q);
+}
+// increment the node counter
+iter->counter++;
+}
+CxTreeVisitor cx_tree_visitor(
+void *root,
+ptrdiff_t loc_children,
+ptrdiff_t loc_next
+) {
+CxTreeVisitor iter;
+iter.loc_children = loc_children;
+iter.loc_next = loc_next;
+// initialize members
+iter.skip = false;
+iter.queue_next = NULL;
+iter.queue_last = NULL;
+// assign base iterator functions
+iter.base.mutating = false;
+iter.base.remove = false;
+iter.base.current_impl = NULL;
+iter.base.valid = cx_tree_visitor_valid;
+iter.base.next = cx_tree_visitor_next;
+iter.base.current = cx_tree_visitor_current;
+// visit the root node
+iter.node = root;
+if (root != NULL) {
+iter.counter = 1;
+iter.depth = 1;
+} else {
+iter.counter = 0;
+iter.depth = 0;
+}
+return iter;
+}
+static void cx_tree_add_link_duplicate(
+void *original, void *duplicate,
+ptrdiff_t loc_parent, ptrdiff_t loc_children, ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev, ptrdiff_t loc_next
+) {
+void *shared_parent = tree_parent(original);
+if (shared_parent == NULL) {
+cx_tree_link(original, duplicate, cx_tree_ptr_locations);
+} else {
+cx_tree_link(shared_parent, duplicate, cx_tree_ptr_locations);
+}
+}
+static void cx_tree_add_link_new(
+void *parent, void *node, cx_tree_search_func sfunc,
+ptrdiff_t loc_parent, ptrdiff_t loc_children, ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev, ptrdiff_t loc_next
+) {
+// check the current children one by one,
+// if they could be children of the new node
+void *child = tree_children(parent);
+while (child != NULL) {
+void *next = tree_next(child);
+if (sfunc(node, child) > 0) {
+// the sibling could be a child -> re-link
+cx_tree_link(node, child, cx_tree_ptr_locations);
+}
+child = next;
+}
+// add new node as new child
+cx_tree_link(parent, node, cx_tree_ptr_locations);
+}
+int cx_tree_add(
+const void *src,
+cx_tree_search_func sfunc,
+cx_tree_node_create_func cfunc,
+void *cdata,
+void **cnode,
+void *root,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+) {
+*cnode = cfunc(src, cdata);
+if (*cnode == NULL) return 1;
+cx_tree_zero_pointers(*cnode, cx_tree_ptr_locations);
+void *match = NULL;
+int result = cx_tree_search(
+root,
+*cnode,
+sfunc,
+&match,
+loc_children,
+loc_next
+);
+if (result < 0) {
+// node does not fit into the tree - return non-zero value
+return 1;
+} else if (result == 0) {
+// data already found in the tree, link duplicate
+cx_tree_add_link_duplicate(match, *cnode, cx_tree_ptr_locations);
+} else {
+// closest match found, add new node
+cx_tree_add_link_new(match, *cnode, sfunc, cx_tree_ptr_locations);
+}
+return 0;
+}
+unsigned int cx_tree_add_look_around_depth = 3;
+size_t cx_tree_add_iter(
+struct cx_iterator_base_s *iter,
+size_t num,
+cx_tree_search_func sfunc,
+cx_tree_node_create_func cfunc,
+void *cdata,
+void **failed,
+void *root,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+) {
+// erase the failed pointer
+*failed = NULL;
+// iter not valid? cancel...
+if (!iter->valid(iter)) return 0;
+size_t processed = 0;
+void *current_node = root;
+const void *elem;
+for (void **eptr; processed < num &&
+iter->valid(iter) && (eptr = iter->current(iter)) != NULL;
+iter->next(iter)) {
+elem = *eptr;
+// create the new node
+void *new_node = cfunc(elem, cdata);
+if (new_node == NULL) return processed;
+cx_tree_zero_pointers(new_node, cx_tree_ptr_locations);
+// start searching from current node
+void *match;
+int result;
+unsigned int look_around_retries = cx_tree_add_look_around_depth;
+cx_tree_add_look_around_retry:
+result = cx_tree_search(
+current_node,
+new_node,
+sfunc,
+&match,
+loc_children,
+loc_next
+);
+if (result < 0) {
+// traverse upwards and try to find better parents
+void *parent = tree_parent(current_node);
+if (parent != NULL) {
+if (look_around_retries > 0) {
+look_around_retries--;
+current_node = parent;
+} else {
+// look around retries exhausted, start from the root
+current_node = root;
+}
+goto cx_tree_add_look_around_retry;
+} else {
+// no parents. so we failed
+*failed = new_node;
+return processed;
+}
+} else if (result == 0) {
+// data already found in the tree, link duplicate
+cx_tree_add_link_duplicate(match, new_node, cx_tree_ptr_locations);
+// but stick with the original match, in case we needed a new root
+current_node = match;
+} else {
+// closest match found, add new node as child
+cx_tree_add_link_new(match, new_node, sfunc,
+cx_tree_ptr_locations);
+current_node = match;
+}
+processed++;
+}
+return processed;
+}
+size_t cx_tree_add_array(
+const void *src,
+size_t num,
+size_t elem_size,
+cx_tree_search_func sfunc,
+cx_tree_node_create_func cfunc,
+void *cdata,
+void **failed,
+void *root,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+) {
+// erase failed pointer
+*failed = NULL;
+// super special case: zero elements
+if (num == 0) {
+return 0;
+}
+// special case: one element does not need an iterator
+if (num == 1) {
+void *node;
+if (0 == cx_tree_add(
+src, sfunc, cfunc, cdata, &node, root,
+loc_parent, loc_children, loc_last_child,
+loc_prev, loc_next)) {
+return 1;
+} else {
+*failed = node;
+return 0;
+}
+}
+// otherwise, create iterator and hand over to other function
+CxIterator iter = cxIterator(src, elem_size, num);
+return cx_tree_add_iter(cxIteratorRef(iter), num, sfunc,
+cfunc, cdata, failed, root,
+loc_parent, loc_children, loc_last_child,
+loc_prev, loc_next);
+}
+static void cx_tree_default_destructor(CxTree *tree) {
+if (tree->simple_destructor != NULL || tree->advanced_destructor != NULL) {
+CxTreeIterator iter = tree->cl->iterator(tree, true);
+cx_foreach(void *, node, iter) {
+if (iter.exiting) {
+if (tree->simple_destructor) {
+tree->simple_destructor(node);
+}
+if (tree->advanced_destructor) {
+tree->advanced_destructor(tree->destructor_data, node);
+}
+}
+}
+}
+cxFree(tree->allocator, tree);
+}
+static CxTreeIterator cx_tree_default_iterator(
+CxTree *tree,
+bool visit_on_exit
+) {
+return cx_tree_iterator(
+tree->root, visit_on_exit,
+tree->loc_children, tree->loc_next
+);
+}
+static CxTreeVisitor cx_tree_default_visitor(CxTree *tree) {
+return cx_tree_visitor(tree->root, tree->loc_children, tree->loc_next);
+}
+static int cx_tree_default_insert_element(
+CxTree *tree,
+const void *data
+) {
+void *node;
+if (tree->root == NULL) {
+node = tree->node_create(data, tree);
+if (node == NULL) return 1;
+cx_tree_zero_pointers(node, cx_tree_node_layout(tree));
+tree->root = node;
+tree->size = 1;
+return 0;
+}
+int result = cx_tree_add(data, tree->search, tree->node_create,
+tree, &node, tree->root, cx_tree_node_layout(tree));
+if (0 == result) {
+tree->size++;
+} else {
+cxFree(tree->allocator, node);
+}
+return result;
+}
+static size_t cx_tree_default_insert_many(
+CxTree *tree,
+struct cx_iterator_base_s *iter,
+size_t n
+) {
+size_t ins = 0;
+if (!iter->valid(iter)) return 0;
+if (tree->root == NULL) {
+// use the first element from the iter to create the root node
+void **eptr = iter->current(iter);
+void *node = tree->node_create(*eptr, tree);
+if (node == NULL) return 0;
+cx_tree_zero_pointers(node, cx_tree_node_layout(tree));
+tree->root = node;
+ins = 1;
+iter->next(iter);
+}
+void *failed;
+ins += cx_tree_add_iter(iter, n, tree->search, tree->node_create,
+tree, &failed, tree->root, cx_tree_node_layout(tree));
+tree->size += ins;
+if (ins < n) {
+cxFree(tree->allocator, failed);
+}
+return ins;
+}
+static void *cx_tree_default_find(
+CxTree *tree,
+const void *subtree,
+const void *data
+) {
+if (tree->root == NULL) return NULL;
+void *found;
+if (0 == cx_tree_search_data(
+subtree,
+data,
+tree->search_data,
+&found,
+tree->loc_children,
+tree->loc_next
+)) {
+return found;
+} else {
+return NULL;
+}
+}
+static cx_tree_class cx_tree_default_class = {
+cx_tree_default_destructor,
+cx_tree_default_insert_element,
+cx_tree_default_insert_many,
+cx_tree_default_find,
+cx_tree_default_iterator,
+cx_tree_default_visitor
+};
+CxTree *cxTreeCreate(
+const CxAllocator *allocator,
+cx_tree_node_create_func create_func,
+cx_tree_search_func search_func,
+cx_tree_search_data_func search_data_func,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+) {
+CxTree *tree = cxMalloc(allocator, sizeof(CxTree));
+if (tree == NULL) return NULL;
+tree->cl = &cx_tree_default_class;
+tree->allocator = allocator;
+tree->node_create = create_func;
+tree->search = search_func;
+tree->search_data = search_data_func;
+tree->advanced_destructor = (cx_destructor_func2) cxFree;
+tree->destructor_data = (void *) allocator;
+tree->loc_parent = loc_parent;
+tree->loc_children = loc_children;
+tree->loc_last_child = loc_last_child;
+tree->loc_prev = loc_prev;
+tree->loc_next = loc_next;
+tree->root = NULL;
+tree->size = 0;
+return tree;
+}
+CxTree *cxTreeCreateWrapped(
+const CxAllocator *allocator,
+void *root,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+) {
+CxTree *tree = cxMalloc(allocator, sizeof(CxTree));
+if (tree == NULL) return NULL;
+tree->cl = &cx_tree_default_class;
+// set the allocator anyway, just in case...
+tree->allocator = allocator;
+tree->node_create = NULL;
+tree->search = NULL;
+tree->search_data = NULL;
+tree->simple_destructor = NULL;
+tree->advanced_destructor = NULL;
+tree->destructor_data = NULL;
+tree->loc_parent = loc_parent;
+tree->loc_children = loc_children;
+tree->loc_last_child = loc_last_child;
+tree->loc_prev = loc_prev;
+tree->loc_next = loc_next;
+tree->root = root;
+tree->size = cxTreeSubtreeSize(tree, root);
+return tree;
+}
+int cxTreeAddChild(
+CxTree *tree,
+void *parent,
+const void *data) {
+void *node = tree->node_create(data, tree);
+if (node == NULL) return 1;
+cx_tree_zero_pointers(node, cx_tree_node_layout(tree));
+cx_tree_link(parent, node, cx_tree_node_layout(tree));
+tree->size++;
+return 0;
+}
+size_t cxTreeSubtreeSize(CxTree *tree, void *subtree_root) {
+CxTreeVisitor visitor = cx_tree_visitor(
+subtree_root,
+tree->loc_children,
+tree->loc_next
+);
+while (cxIteratorValid(visitor)) {
+cxIteratorNext(visitor);
+}
+return visitor.counter;
+}
+size_t cxTreeSubtreeDepth(CxTree *tree, void *subtree_root) {
+CxTreeVisitor visitor = cx_tree_visitor(
+subtree_root,
+tree->loc_children,
+tree->loc_next
+);
+while (cxIteratorValid(visitor)) {
+cxIteratorNext(visitor);
+}
+return visitor.depth;
+}
+size_t cxTreeDepth(CxTree *tree) {
+CxTreeVisitor visitor = tree->cl->visitor(tree);
+while (cxIteratorValid(visitor)) {
+cxIteratorNext(visitor);
+}
+return visitor.depth;
+}
+int cxTreeRemove(
+CxTree *tree,
+void *node,
+cx_tree_relink_func relink_func
+) {
+if (node == tree->root) return 1;
+// determine the new parent
+ptrdiff_t loc_parent = tree->loc_parent;
+void *new_parent = tree_parent(node);
+// first, unlink from the parent
+cx_tree_unlink(node, cx_tree_node_layout(tree));
+// then relink each child
+ptrdiff_t loc_children = tree->loc_children;
+ptrdiff_t loc_next = tree->loc_next;
+void *child = tree_children(node);
+while (child != NULL) {
+// forcibly set the parent to NULL - we do not use the unlink function
+// because that would unnecessarily modify the children linked list
+tree_parent(child) = NULL;
+// update contents, if required
+if (relink_func != NULL) {
+relink_func(child, node, new_parent);
+}
+// link to new parent
+cx_tree_link(new_parent, child, cx_tree_node_layout(tree));
+// proceed to next child
+child = tree_next(child);
+}
+// clear the linked list of the removed node
+tree_children(node) = NULL;
+ptrdiff_t loc_last_child = tree->loc_last_child;
+if (loc_last_child >= 0) tree_last_child(node) = NULL;
+// the tree now has one member less
+tree->size--;
+return 0;
+}
+void cxTreeRemoveSubtree(CxTree *tree, void *node) {
+if (node == tree->root) {
+tree->root = NULL;
+tree->size = 0;
+return;
+}
+size_t subtree_size = cxTreeSubtreeSize(tree, node);
+cx_tree_unlink(node, cx_tree_node_layout(tree));
+tree->size -= subtree_size;
+}

Mercurial > hg > toolkit / file comparison

comparison: ucx/tree.c

ucx/tree.c