Ported from godot 4: Optimize Node children management

* Adding and removing child nodes is now constant time, speed up should be huge.
* Searching for node paths as in ("path/to/node") should be far faster too.
This changes the children management and makes it a hashmap, optimizing most StringName based operations.
Most operations should be severe speed up without breaking compatibility.
This should fix many issues regarding to node access performance, and may also speed up editor start/end, but benchmarks are needed. So if you want to test, please make some benchmarks!
- reduz
ab5fc22f67

scene/main/node.cpp

@@ -185,7 +185,7 @@ void Node::_notification(int p_notification) {
 
 			// kill children as cleanly as possible
 			while (data.children.size()) {
-				Node *child = data.children[data.children.size() - 1]; //begin from the end because its faster and more consistent with creation
+				Node *child = data.children.back()->value(); // begin from the end because its faster and more consistent with creation
 				memdelete(child);
 			}
 		} break;
@@ -195,9 +195,11 @@ void Node::_notification(int p_notification) {
 void Node::_propagate_ready() {
 	data.ready_notified = true;
 	data.blocked++;
-	for (int i = 0; i < data.children.size(); i++) {
+
-		data.children[i]->_propagate_ready();
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
+		E->value()->_propagate_ready();
 	}
+
 	data.blocked--;
 
 	notification(NOTIFICATION_POST_ENTER_TREE);
@@ -233,8 +235,8 @@ void Node::_propagate_physics_interpolated(bool p_interpolated) {
 	_physics_interpolated_changed();
 
 	data.blocked++;
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		data.children[i]->_propagate_physics_interpolated(p_interpolated);
+		E->value()->_propagate_physics_interpolated(p_interpolated);
 	}
 	data.blocked--;
 }
@@ -245,8 +247,8 @@ void Node::_propagate_physics_interpolation_reset_requested() {
 	}
 
 	data.blocked++;
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		data.children[i]->_propagate_physics_interpolation_reset_requested();
+		E->value()->_propagate_physics_interpolation_reset_requested();
 	}
 	data.blocked--;
 }
@@ -296,9 +298,9 @@ void Node::_propagate_enter_tree() {
 	data.blocked++;
 	//block while adding children
 
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		if (!data.children[i]->is_inside_tree()) { // could have been added in enter_tree
+		if (!E->value()->is_inside_tree()) { // could have been added in enter_tree
-			data.children[i]->_propagate_enter_tree();
+			E->value()->_propagate_enter_tree();
 		}
 	}
 
@@ -339,8 +341,8 @@ void Node::_propagate_after_exit_branch(bool p_exiting_tree) {
 	}
 
 	data.blocked++;
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		data.children[i]->_propagate_after_exit_branch(p_exiting_tree);
+		E->value()->_propagate_after_exit_branch(p_exiting_tree);
 	}
 	data.blocked--;
 
@@ -375,8 +377,8 @@ void Node::_propagate_exit_tree() {
 #endif
 	data.blocked++;
 
-	for (int i = data.children.size() - 1; i >= 0; i--) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.back(); E; E = E->prev) {
-		data.children[i]->_propagate_exit_tree();
+		E->value()->_propagate_exit_tree();
 	}
 
 	data.blocked--;
@@ -419,13 +421,15 @@ void Node::_propagate_exit_tree() {
 
 void Node::move_child(Node *p_child, int p_pos) {
 	ERR_FAIL_NULL(p_child);
-	ERR_FAIL_INDEX_MSG(p_pos, data.children.size() + 1, vformat("Invalid new child position: %d.", p_pos));
+	ERR_FAIL_INDEX_MSG(static_cast<uint32_t>(p_pos), data.children.size() + 1, vformat("Invalid new child position: %d.", p_pos));
 	ERR_FAIL_COND_MSG(p_child->data.parent != this, "Child is not a child of this node.");
 	ERR_FAIL_COND_MSG(data.blocked > 0, "Parent node is busy setting up children, move_child() failed. Consider using call_deferred(\"move_child\") instead (or \"popup\" if this is from a popup).");
 
+	_update_children_cache();
+
 	// Specifying one place beyond the end
 	// means the same as moving to the last position
-	if (p_pos == data.children.size()) {
+	if (static_cast<uint32_t>(p_pos) == data.children.size()) {
 		p_pos--;
 	}
 
@@ -436,8 +440,8 @@ void Node::move_child(Node *p_child, int p_pos) {
 	int motion_from = MIN(p_pos, p_child->data.pos);
 	int motion_to = MAX(p_pos, p_child->data.pos);
 
-	data.children.remove(p_child->data.pos);
+	data.children_cache.remove(p_child->data.pos);
-	data.children.insert(p_pos, p_child);
+	data.children_cache.insert(p_pos, p_child);
 
 	if (data.tree) {
 		data.tree->tree_changed();
@@ -446,7 +450,7 @@ void Node::move_child(Node *p_child, int p_pos) {
 	data.blocked++;
 	//new pos first
 	for (int i = motion_from; i <= motion_to; i++) {
-		data.children[i]->data.pos = i;
+		data.children_cache[i]->data.pos = i;
 	}
 	// notification second
 	move_child_notify(p_child);
@@ -559,8 +563,8 @@ void Node::_propagate_pause_owner(Node *p_owner) {
 		return;
 	}
 	data.pause_owner = p_owner;
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		data.children[i]->_propagate_pause_owner(p_owner);
+		E->value()->_propagate_pause_owner(p_owner);
 	}
 }
 
@@ -571,8 +575,8 @@ void Node::_propagate_groups_dirty() {
 		}
 	}
 
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		data.children[i]->_propagate_groups_dirty();
+		E->value()->_propagate_groups_dirty();
 	}
 }
 
@@ -611,8 +615,9 @@ void Node::sees_add(Node *p_node) {
 	p_node->seen_by_add(this);
 
 	for (int i = 0; i < data._sees.size(); ++i) {
-		if (data._sees.get(i) == p_node)
+		if (data._sees.get(i) == p_node) {
 			return;
+		}
 	}
 
 	data._sees.push_back(p_node);
@@ -638,8 +643,9 @@ void Node::seen_by_add(Node *p_node) {
 	ERR_FAIL_COND(!ObjectDB::instance_validate(p_node));
 
 	for (int i = 0; i < data._seen_by.size(); ++i) {
-		if (data._seen_by.get(i) == p_node)
+		if (data._seen_by.get(i) == p_node) {
 			return;
+		}
 	}
 
 	data._seen_by.push_back(p_node);
@@ -652,8 +658,8 @@ void Node::set_network_master(int p_peer_id, bool p_recursive) {
 	data.network_master = p_peer_id;
 
 	if (p_recursive) {
-		for (int i = 0; i < data.children.size(); i++) {
+		for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-			data.children[i]->set_network_master(p_peer_id, true);
+			E->value()->set_network_master(p_peer_id, true);
 		}
 	}
 }
@@ -741,8 +747,10 @@ void Node::vrpc(const StringName &p_method, VARIANT_ARG_DECLARE) {
 
 	int argc = 0;
 	for (int i = 0; i < VARIANT_ARG_MAX; i++) {
-		if (argptr[i]->get_type() == Variant::NIL)
+		if (argptr[i]->get_type() == Variant::NIL) {
 			break;
+		}
+
 		argc++;
 	}
 
@@ -772,8 +780,10 @@ void Node::vrpc_unreliable(const StringName &p_method, VARIANT_ARG_DECLARE) {
 
 	int argc = 0;
 	for (int i = 0; i < VARIANT_ARG_MAX; i++) {
-		if (argptr[i]->get_type() == Variant::NIL)
+		if (argptr[i]->get_type() == Variant::NIL) {
 			break;
+		}
+
 		argc++;
 	}
 
@@ -1268,10 +1278,13 @@ void Node::set_name(const String &p_name) {
 		_release_unique_name_in_owner();
 	}
 
+	String old_name = data.name;
 	data.name = name;
 
 	if (data.parent) {
+		data.parent->data.children.erase(old_name);
 		data.parent->_validate_child_name(this);
+		data.parent->data.children.insert(data.name, this);
 	}
 
 	if (data.unique_name_in_owner && data.owner) {
@@ -1327,19 +1340,8 @@ void Node::_validate_child_name(Node *p_child, bool p_force_human_readable) {
 			//new unique name must be assigned
 			unique = false;
 		} else {
-			//check if exists
+			const Node *const *existing = data.children.getptr(p_child->data.name);
-			Node **children = data.children.ptrw();
+			unique = !existing || *existing == p_child;
-			int cc = data.children.size();
-
-			for (int i = 0; i < cc; i++) {
-				if (children[i] == p_child) {
-					continue;
-				}
-				if (children[i]->data.name == p_child->data.name) {
-					unique = false;
-					break;
-				}
-			}
 		}
 
 		if (!unique) {
@@ -1395,25 +1397,9 @@ void Node::_generate_serial_child_name(const Node *p_child, StringName &name) co
 		}
 	}
 
-	//quickly test if proposed name exists
+	const Node *const *existing = data.children.getptr(name);
-	int cc = data.children.size(); //children count
+	if (!existing || *existing == p_child) { // Unused, or is current node.
-	const Node *const *children_ptr = data.children.ptr();
+		return;
-
-	{
-		bool exists = false;
-
-		for (int i = 0; i < cc; i++) {
-			if (children_ptr[i] == p_child) { //exclude self in renaming if its already a child
-				continue;
-			}
-			if (children_ptr[i]->data.name == name) {
-				exists = true;
-			}
-		}
-
-		if (!exists) {
-			return; //if it does not exist, it does not need validation
-		}
 	}
 
 	// Extract trailing number
@@ -1440,16 +1426,9 @@ void Node::_generate_serial_child_name(const Node *p_child, StringName &name) co
 
 	for (;;) {
 		StringName attempt = name_string + nums;
-		bool exists = false;
 
-		for (int i = 0; i < cc; i++) {
+		existing = data.children.getptr(attempt);
-			if (children_ptr[i] == p_child) {
+		bool exists = existing != nullptr && *existing != p_child;
-				continue;
-			}
-			if (children_ptr[i]->data.name == attempt) {
-				exists = true;
-			}
-		}
 
 		if (!exists) {
 			name = attempt;
@@ -1471,8 +1450,16 @@ void Node::_add_child_nocheck(Node *p_child, const StringName &p_name) {
 
 	p_child->data.name = p_name;
 	p_child->data.pos = data.children.size();
-	data.children.push_back(p_child);
+	data.children.insert(p_name, p_child);
 	p_child->data.parent = this;
+
+	if (!data.children_cache_dirty) {
+		// Special case, also add to the cached children array since its cheap.
+		data.children_cache.push_back(p_child);
+	} else {
+		data.children_cache_dirty = true;
+	}
+
 	p_child->notification(NOTIFICATION_PARENTED);
 
 	if (data.tree) {
@@ -1525,45 +1512,30 @@ void Node::remove_child(Node *p_child) {
 	ERR_FAIL_NULL(p_child);
 	ERR_FAIL_COND_MSG(data.blocked > 0, "Parent node is busy setting up children, remove_node() failed. Consider using call_deferred(\"remove_child\", child) instead.");
 
-	int child_count = data.children.size();
+	ERR_FAIL_COND(p_child->data.parent != this);
-	Node **children = data.children.ptrw();
-	int idx = -1;
 
-	if (p_child->data.pos >= 0 && p_child->data.pos < child_count) {
+	/**
-		if (children[p_child->data.pos] == p_child) {
+	 *  Do not change the data.internal_children*cache counters here.
-			idx = p_child->data.pos;
+	 *  Because if nodes are re-added, the indices can remain
-		}
+	 *  greater-than-everything indices and children added remain
-	}
+	 *  properly ordered.
+	 *
+	 *  All children indices and counters will be updated next time the
+	 *  cache is re-generated.
+	 */
 
-	if (idx == -1) { //maybe removed while unparenting or something and index was not updated, so just in case the above fails, try this.
+	data.blocked++;
-		for (int i = 0; i < child_count; i++) {
-			if (children[i] == p_child) {
-				idx = i;
-				break;
-			}
-		}
-	}
-
-	ERR_FAIL_COND_MSG(idx == -1, vformat("Cannot remove child node '%s' as it is not a child of this node.", p_child->get_name()));
-	//ERR_FAIL_COND( p_child->data.blocked > 0 );
-
-	//if (data.scene) { does not matter
 
 	p_child->_set_tree(nullptr);
-	//}
 
 	remove_child_notify(p_child);
 	p_child->notification(NOTIFICATION_UNPARENTED);
 
-	data.children.remove(idx);
+	data.blocked--;
 
-	//update pointer and size
+	data.children_cache_dirty = true;
-	child_count = data.children.size();
+	bool success = data.children.erase(p_child->data.name);
-	children = data.children.ptrw();
+	ERR_FAIL_COND_MSG(!success, "Children name does not match parent name in hashtable, this is a bug.");
-
-	for (int i = idx; i < child_count; i++) {
-		children[i]->data.pos = i;
-	}
 
 	notification(NOTIFICATION_CHILD_ORDER_CHANGED);
 	emit_signal(SceneStringNames::get_singleton()->child_order_changed);
@@ -1574,26 +1546,45 @@ void Node::remove_child(Node *p_child) {
 	p_child->_propagate_after_exit_branch(data.inside_tree);
 }
 
+void Node::_update_children_cache_impl() const {
+	// Assign children
+	data.children_cache.resize(data.children.size());
+
+	int idx = 0;
+	for (const HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
+		data.children_cache[idx] = E->value();
+		idx++;
+	}
+
+	// Sort them
+	data.children_cache.sort_custom<ComparatorByIndex>();
+
+	// Update indices
+	for (uint32_t i = 0; i < data.children_cache.size(); i++) {
+		data.children_cache[i]->data.pos = i;
+	}
+
+	data.children_cache_dirty = false;
+}
+
 int Node::get_child_count() const {
 	return data.children.size();
 }
 Node *Node::get_child(int p_index) const {
-	ERR_FAIL_INDEX_V(p_index, data.children.size(), nullptr);
+	ERR_FAIL_INDEX_V(static_cast<uint32_t>(p_index), data.children.size(), nullptr);
 
-	return data.children[p_index];
+	_update_children_cache();
+
+	return data.children_cache[p_index];
 }
 
 Node *Node::_get_child_by_name(const StringName &p_name) const {
-	int cc = data.children.size();
+	const Node *const *node = data.children.getptr(p_name);
-	Node *const *cd = data.children.ptr();
+	if (node) {
-
+		return const_cast<Node *>(*node);
-	for (int i = 0; i < cc; i++) {
+	} else {
-		if (cd[i]->data.name == p_name) {
+		return nullptr;
-			return cd[i];
-		}
 	}
-
-	return nullptr;
 }
 
 Node *Node::get_node_or_null(const NodePath &p_path) const {
@@ -1656,17 +1647,12 @@ Node *Node::get_node_or_null(const NodePath &p_path) const {
 		} else {
 			next = nullptr;
 
-			for (int j = 0; j < current->data.children.size(); j++) {
+			const Node *const *node = current->data.children.getptr(name);
-				Node *child = current->data.children[j];
+			if (node) {
-
+				next = const_cast<Node *>(*node);
-				if (child->data.name == name) {
+			} else {
-					next = child;
-					break;
-				}
-			}
-			if (next == nullptr) {
 				return nullptr;
-			};
+			}
 		}
 		current = next;
 	}
@@ -1705,8 +1691,12 @@ bool Node::has_node(const NodePath &p_path) const {
 }
 
 Node *Node::find_node(const String &p_mask, bool p_recursive, bool p_owned) const {
-	Node *const *cptr = data.children.ptr();
+	ERR_FAIL_COND_V(p_mask.empty(), NULL);
-	int ccount = data.children.size();
+
+	_update_children_cache();
+
+	Node *const *cptr = data.children_cache.ptr();
+	int ccount = data.children_cache.size();
 	for (int i = 0; i < ccount; i++) {
 		if (p_owned && !cptr[i]->data.owner) {
 			continue;
@@ -1763,6 +1753,9 @@ bool Node::is_greater_than(const Node *p_node) const {
 
 	ERR_FAIL_COND_V(data.depth < 0, false);
 	ERR_FAIL_COND_V(p_node->data.depth < 0, false);
+
+	_update_children_cache();
+
 #ifdef NO_ALLOCA
 
 	Vector<int> this_stack;
@@ -1782,7 +1775,7 @@ bool Node::is_greater_than(const Node *p_node) const {
 	int idx = data.depth - 1;
 	while (n) {
 		ERR_FAIL_INDEX_V(idx, data.depth, false);
-		this_stack[idx--] = n->data.pos;
+		this_stack[idx--] = n->get_index();
 		n = n->data.parent;
 	}
 	ERR_FAIL_COND_V(idx != -1, false);
@@ -1790,7 +1783,7 @@ bool Node::is_greater_than(const Node *p_node) const {
 	idx = p_node->data.depth - 1;
 	while (n) {
 		ERR_FAIL_INDEX_V(idx, p_node->data.depth, false);
-		that_stack[idx--] = n->data.pos;
+		that_stack[idx--] = n->get_index();
 
 		n = n->data.parent;
 	}
@@ -1824,8 +1817,8 @@ void Node::get_owned_by(Node *p_by, List<Node *> *p_owned) {
 		p_owned->push_back(this);
 	}
 
-	for (int i = 0; i < get_child_count(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		get_child(i)->get_owned_by(p_by, p_owned);
+		E->value()->get_owned_by(p_by, p_owned);
 	}
 }
 
@@ -2101,9 +2094,10 @@ int Node::get_persistent_group_count() const {
 void Node::_print_tree_pretty(const String &prefix, const bool last) {
 	String new_prefix = last ? String::utf8(" ┖╴") : String::utf8(" ┠╴");
 	print_line(prefix + new_prefix + String(get_name()));
-	for (int i = 0; i < data.children.size(); i++) {
+	_update_children_cache();
+	for (uint32_t i = 0; i < data.children_cache.size(); i++) {
 		new_prefix = last ? String::utf8("   ") : String::utf8(" ┃ ");
-		data.children[i]->_print_tree_pretty(prefix + new_prefix, i == data.children.size() - 1);
+		data.children_cache[i]->_print_tree_pretty(prefix + new_prefix, i == data.children_cache.size() - 1);
 	}
 }
 
@@ -2117,15 +2111,19 @@ void Node::print_tree() {
 
 void Node::_print_tree(const Node *p_node) {
 	print_line(String(p_node->get_path_to(this)));
-	for (int i = 0; i < data.children.size(); i++) {
+
-		data.children[i]->_print_tree(p_node);
+	_update_children_cache();
+
+	for (uint32_t i = 0; i < data.children_cache.size(); i++) {
+		data.children_cache[i]->_print_tree(p_node);
 	}
 }
 
 void Node::_propagate_reverse_notification(int p_notification) {
 	data.blocked++;
-	for (int i = data.children.size() - 1; i >= 0; i--) {
+
-		data.children[i]->_propagate_reverse_notification(p_notification);
+	for (HashMap<StringName, Node *>::Element *E = data.children.back(); E; E = E->prev) {
+		E->value()->_propagate_reverse_notification(p_notification);
 	}
 
 	notification(p_notification, true);
@@ -2141,8 +2139,8 @@ void Node::_propagate_deferred_notification(int p_notification, bool p_reverse)
 		MessageQueue::get_singleton()->push_notification(this, p_notification);
 	}
 
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		data.children[i]->_propagate_deferred_notification(p_notification, p_reverse);
+		E->value()->_propagate_deferred_notification(p_notification, p_reverse);
 	}
 
 	if (p_reverse) {
@@ -2156,9 +2154,10 @@ void Node::propagate_notification(int p_notification) {
 	data.blocked++;
 	notification(p_notification);
 
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		data.children[i]->propagate_notification(p_notification);
+		E->value()->propagate_notification(p_notification);
 	}
+
 	data.blocked--;
 }
 
@@ -2169,8 +2168,8 @@ void Node::propagate_call(const StringName &p_method, const Array &p_args, const
 		callv(p_method, p_args);
 	}
 
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		data.children[i]->propagate_call(p_method, p_args, p_parent_first);
+		E->value()->propagate_call(p_method, p_args, p_parent_first);
 	}
 
 	if (!p_parent_first && has_method(p_method)) {
@@ -2186,16 +2185,12 @@ void Node::_propagate_replace_owner(Node *p_owner, Node *p_by_owner) {
 	}
 
 	data.blocked++;
-	for (int i = 0; i < data.children.size(); i++) {
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
-		data.children[i]->_propagate_replace_owner(p_owner, p_by_owner);
+		E->value()->_propagate_replace_owner(p_owner, p_by_owner);
 	}
 	data.blocked--;
 }
 
-int Node::get_index() const {
-	return data.pos;
-}
-
 Ref<SceneTreeTween> Node::create_tween() {
 	ERR_FAIL_COND_V_MSG(!data.tree, nullptr, "Can't create SceneTreeTween when not inside scene tree.");
 	Ref<SceneTreeTween> tween = get_tree()->create_tween();
@@ -2206,14 +2201,16 @@ Ref<SceneTreeTween> Node::create_tween() {
 void Node::remove_and_skip() {
 	ERR_FAIL_COND(!data.parent);
 
+	_update_children_cache();
+
 	Node *new_owner = get_owner();
 
 	List<Node *> children;
 
 	while (true) {
 		bool clear = true;
-		for (int i = 0; i < data.children.size(); i++) {
+		for (uint32_t i = 0; i < data.children_cache.size(); i++) {
-			Node *c_node = data.children[i];
+			Node *c_node = data.children_cache[i];
 			if (!c_node->get_owner()) {
 				continue;
 			}
@@ -3161,8 +3158,9 @@ void Node::get_argument_options(const StringName &p_function, int p_idx, List<St
 
 void Node::clear_internal_tree_resource_paths() {
 	clear_internal_resource_paths();
-	for (int i = 0; i < data.children.size(); i++) {
+
-		data.children[i]->clear_internal_tree_resource_paths();
+	for (HashMap<StringName, Node *>::Element *E = data.children.front(); E; E = E->next) {
+		E->value()->clear_internal_tree_resource_paths();
 	}
 }
 
@@ -3509,12 +3507,14 @@ Node::~Node() {
 	data.grouped.clear();
 	data.owned.clear();
 	data.children.clear();
+	data.children_cache.clear();
 
 	data._sees.clear();
 	data._seen_by.clear();
 
 	ERR_FAIL_COND(data.parent);
 	ERR_FAIL_COND(data.children.size());
+	ERR_FAIL_COND(data.children_cache.size());
 
 	orphan_node_count--;
 }

scene/main/node.h

@@ -32,6 +32,7 @@
 
 #include "core/object/object.h"
 
+#include "core/containers/hash_map.h"
 #include "core/containers/rb_map.h"
 #include "core/string/node_path.h"
 #include "scene/main/scene_tree.h"
@@ -91,6 +92,12 @@ private:
 		GroupData() { persistent = false; }
 	};
 
+	struct ComparatorByIndex {
+		bool operator()(const Node *p_left, const Node *p_right) const {
+			return p_left->data.pos < p_right->data.pos;
+		}
+	};
+
 	struct Data {
 		String filename;
 		Ref<SceneState> instance_state;
@@ -98,7 +105,9 @@ private:
 
 		Node *parent;
 		Node *owner;
-		Vector<Node *> children; // list of children
+		HashMap<StringName, Node *> children;
+		mutable bool children_cache_dirty = true;
+		mutable LocalVector<Node *> children_cache;
 		HashMap<StringName, Node *> owned_unique_nodes;
 		bool unique_name_in_owner = false;
 
@@ -225,6 +234,14 @@ private:
 	void _release_unique_name_in_owner();
 	void _acquire_unique_name_in_owner();
 
+	_FORCE_INLINE_ void _update_children_cache() const {
+		if (unlikely(data.children_cache_dirty)) {
+			_update_children_cache_impl();
+		}
+	}
+
+	void _update_children_cache_impl() const;
+
 protected:
 	void _block() {
 		data.blocked++;
@@ -377,7 +394,21 @@ public:
 	bool is_unique_name_in_owner() const;
 
 	void remove_and_skip();
-	int get_index() const;
+	//int get_index() const;
+
+	//int Node::get_index() const {/
+	//	return data.pos;
+	//}
+
+	_FORCE_INLINE_ int get_index() const {
+		if (!data.parent) {
+			return data.pos;
+		}
+
+		data.parent->_update_children_cache();
+
+		return data.pos;
+	}
 
 	Ref<SceneTreeTween> create_tween();