function generateData ($size, $depth, $parent) {
	$result = array();
	for ($i = 0; $i < $size; $i++) {
		$elem = new Elem;
		$elem->setData ($parent ? $parent->getData() . '.' . ($i+1) : '#'.($i+1));
		$elem->setChildren ($depth ? generateData($size, $depth-1, $elem) : array());
		$elem->setParent ($parent);
		$result[] = $elem;
	}
	return $result;
}

function insertTreeFHRecursive ($tree) {
	$qElem = "INSERT INTO `Elements` (`ID`, `Data`) VALUES (NULL, '%s')";
	$qHier = "INSERT INTO `ElementsHierarchy`(`ElemID`,`ParentID`,`Level`) VALUES (%s)";
	$qParents = "SELECT * FROM `ElementsHierarchy` WHERE `ElemID` = '%d'";
	foreach ($tree as $elem) {
		$query   = sprintf($qElem, Db::escape($elem->getData()));
		$elem->setId(Db::execute($query));
		$parents = array();
		if ($elem->getParent()) {
			$parentId = $elem->getParent()->getId();
			$parentParents = Db::select(sprintf($qParents, $parentId));
			foreach ($parentParents as $k => $v) {
				$parents[] = join (',', array ($elem->getId(), $v['ParentID'] ? $v['ParentID'] : 'NULL', $v['Level']+1));
			}
			$parents[] = join (',', array ($elem->getId(), $parentId, 1));
			$parentsString = join ('), (', $parents);
		} else {
			$parentsString = join (',', array($elem->getId(), 'NULL', 1));
		}
		Db::execute(sprintf($qHier, $parentsString));
		if ($elem->getChildren()) {
			insertTreeRecursive($elem->getChildren());
		}
	}
}

function insertTreeMPRecursive ($tree) {
	$qElem = "INSERT INTO `ElementsMP` (`ID`, `Data`, `Path`) VALUES (NULL, '%s', %s)";
	$qParent = "SELECT `Path` FROM `ElementsMP` WHERE `ID` = '%d'";
	foreach ($tree as $elem) {
		if ($elem->getParent()) {
			$parentID = $elem->getParent()->getId();
			$parent = Db::select(sprintf($qParent, $parentID));
			if ($parent[0]['Path']) {
				$path = $parent[0]['Path'] . $parentID . '.';
			} else {
				$path = '.' . $parentID . '.';
			}
			$query = sprintf($qElem, $elem->getData(), "'$path'");
			$elem->setId(Db::execute($query));
		} else {
			$query = sprintf($qElem, $elem->getData(), 'NULL');
			$elem->setId(Db::execute($query));
		}
		if ($elem->getChildren()) {
			insertTreeMPRecursive($elem->getChildren());
		}
	}
}


function getTreeByParent_MP ($id) {
	$id = (int) $id;
	Db::select("SELECT SQL_NO_CACHE * FROM `ElementsMP` WHERE `Path` LIKE '%.$id.%'");
}

function getTreeByParent_FH ($id) {
	$id = (int) $id;
	Db::select("
SELECT SQL_NO_CACHE `Elements`.*, `Parent`.`ParentID` FROM `Elements`
INNER JOIN `ElementsHierarchy` as `Hier`
	ON `Hier`.`ElemID` = `Elements`.`ID`
INNER JOIN `ElementsHierarchy` as `Parent`
	ON (`Parent`.`ElemID` = `Elements`.`ID` AND `Parent`.`Level` = 1)
WHERE `Hier`.`ParentID` = $id OR `Elements`.`Id` = $id
	");
}