/**
* In an augmented interval tree, each node saves the maximum edge of its child subtrees
* This function compares the children max_edge with the current max_edge
* and propagates any change to the parent nodes.
*/
static void
update_max_edge(wmem_tree_node_t *node)
{
wmem_range_t *range;
const wmem_range_t *range_l;
const wmem_range_t *range_r;
guint64 maxEdge = 0;
if(!node) {
return ;
}
range = (wmem_range_t *)node->key;
range_l = (node->left) ? (const wmem_range_t *) (node->left->key) : NULL;
range_r = (node->right) ? (const wmem_range_t *) (node->right->key) : NULL;
maxEdge = range->high;
if(range_r) {
maxEdge = MAX(maxEdge, range_r->max_edge) ;
}
if(range_l) {
maxEdge = MAX(maxEdge, range_l->max_edge) ;
}
/* update the parent nodes only if a change happened (optimization) */
if(range->max_edge != maxEdge) {
range->max_edge = maxEdge;
update_max_edge(node->parent);
}
}
/**
* In an augmented interval tree, each node saves the maximum edge of its child subtrees
* This function compares the children max_edge with the current max_edge
* and propagates any change to the parent nodes.
*/
static void
update_max_edge(wmem_tree_node_t *node)
{
wmem_range_t *range;
wmem_range_t *range_l;
wmem_range_t *range_r;
guint64 maxEdge = 0;
if(!node) {
return ;
}
range = (wmem_range_t *)node->key;
range_l = (node->left) ? (wmem_range_t *) (node->left->key) : NULL;
range_r = (node->right) ? (wmem_range_t *) (node->right->key) : NULL;
maxEdge = range->max_edge;
if(range_r) {
maxEdge = MAX(maxEdge, range_r->max_edge) ;
}
if(range_l) {
maxEdge = MAX(maxEdge, range_l->max_edge) ;
}
/* a change was made, update the parent nodes */
if(range->max_edge != maxEdge) {
range->max_edge = maxEdge;
update_max_edge(node->parent);
}
}
void
wmem_itree_insert(wmem_itree_t *tree, const guint64 low, const guint64 high, void *data)
{
wmem_tree_node_t *node;
wmem_range_t *range = (wmem_range_t *)wmem_new(tree->allocator, wmem_range_t);
g_assert(low <= high);
range->low = low;
range->high = high;
range->max_edge = 0;
node = wmem_tree_insert(tree, range, data, (compare_func)wmem_tree_compare_ranges);
/* in absence of rotation, we still need to update max_edge */
update_max_edge(node);
}
/* after a rotation, some of the children nodes might (dis)appear, thus we need
* to refresh children max_edge. Changes will propagate to parents */
static void update_edges_after_rotation(wmem_tree_node_t *node) {
if(node->left) update_max_edge(node->left);
if(node->right) update_max_edge(node->right);
}