/**
* Add item as left-sibling of node (cannot be the root node).
*
* This is inefficient if the node is not the first child (the head of the
* sibling list) given that the siblings are linked through a one-way list.
*/
void
etree_add_left_sibling(etree_t *tree, void *node, void *item)
{
node_t *n, *i;
etree_check(tree);
g_assert(node != NULL);
g_assert(item != NULL);
g_assert(etree_is_orphan(tree, item));
g_assert(!etree_is_root(tree, node));
n = ptr_add_offset(node, tree->offset);
i = ptr_add_offset(item, tree->offset);
i->parent = n->parent;
i->sibling = n;
if (n == n->parent->child) {
/* node is first child, optimized case */
n->parent->child = i;
} else {
node_t *p;
for (p = n->parent->child; p->sibling != n; p = p->sibling)
/* empty */;
g_assert(p != NULL); /* previous node found */
p->sibling = i;
}
tree->count = 0; /* Tree count is now unknown */
}
/**
* Add item as right-sibling of node (cannot be the root node).
*/
void
etree_add_right_sibling(etree_t *tree, void *node, void *item)
{
node_t *n, *i;
etree_check(tree);
g_assert(node != NULL);
g_assert(item != NULL);
g_assert(etree_is_orphan(tree, item));
g_assert(!etree_is_root(tree, node));
n = ptr_add_offset(node, tree->offset);
i = ptr_add_offset(item, tree->offset);
i->parent = n->parent;
i->sibling = n->sibling;
n->sibling = i;
if (NULL == i->sibling && etree_is_extended(tree)) {
nodex_t *px = (nodex_t *) n->parent;
px->last_child = i;
}
tree->count = 0; /* Tree count is now unknown */
}
/**
* Prepend child to parent.
*
* This is always a fast operation.
*/
void
etree_prepend_child(etree_t *tree, void *parent, void *child)
{
node_t *cn, *pn;
etree_check(tree);
g_assert(parent != NULL);
g_assert(child != NULL);
g_assert(etree_is_orphan(tree, child));
cn = ptr_add_offset(child, tree->offset);
pn = ptr_add_offset(parent, tree->offset);
cn->parent = pn;
cn->sibling = pn->child;
pn->child = cn;
if (etree_is_extended(tree)) {
nodex_t *px = (nodex_t *) pn;
if (NULL == px->last_child) {
g_assert(NULL == cn->sibling); /* Parent did not have any child */
px->last_child = cn;
}
}
tree->count = 0; /* Tree count is now unknown */
}
/**
* Make sure node is orphan.
*/
static void
xnode_orphan_check(const xnode_t * const xn)
{
etree_t t;
xnode_check(xn);
etree_init_root(&t, xn, TRUE, offsetof(xnode_t, node));
g_assert(etree_is_orphan(&t, xn));
}
/**
* Append child to parent.
*
* If this is a frequent operation, consider using an extended tree.
*/
void
etree_append_child(etree_t *tree, void *parent, void *child)
{
node_t *cn, *pn;
etree_check(tree);
g_assert(parent != NULL);
g_assert(child != NULL);
g_assert(etree_is_orphan(tree, child));
cn = ptr_add_offset(child, tree->offset);
pn = ptr_add_offset(parent, tree->offset);
if (etree_is_extended(tree)) {
nodex_t *px = ptr_add_offset(parent, tree->offset);
if (px->last_child != NULL) {
node_t *lcn = px->last_child;
g_assert(0 == ptr_cmp(lcn->parent, px));
g_assert(NULL == lcn->sibling);
lcn->sibling = cn;
} else {
g_assert(NULL == px->child);
px->child = cn;
}
px->last_child = cn;
} else {
if (NULL == pn->child) {
pn->child = cn;
} else {
node_t *lcn = etree_node_last_sibling(pn->child);
lcn->sibling = cn;
}
}
cn->parent = pn;
tree->count = 0; /* Tree count is now unknown */
}
/**
* Computes the root of the tree, starting from any item.
*
* This disregards the actual root in the etree_t structure passed, which may
* be inaccurate, i.e. a sub-node of the actual tree. The only accurate
* information that etree_t must contain is the offset of the node_t within
* the items.
*
* @param tree the tree descriptor (with possible inaccurate root)
* @param item an item belonging to the tree
*
* @return the root of the tree to which item belongs.
*/
void *
etree_find_root(const etree_t *tree, const void *item)
{
const node_t *n, *p;
void *root;
etree_check(tree);
g_assert(item != NULL);
n = const_ptr_add_offset(item, tree->offset);
for (p = n; p != NULL; p = n->parent)
n = p;
root = ptr_add_offset(deconstify_pointer(n), -tree->offset);
g_assert(etree_is_orphan(tree, root)); /* No parent, no sibling */
return root;
}