/**
* Convert a Graph to a phpDocumentor graph, usable for printing
*
* @param \Gliph\Graph\Digraph $graph The graph to print
*
* @return \phpDocumentor\GraphViz\Graph The copied graph
*/
protected function convertGraph(Digraph $graph)
{
$new = Graph::create("dump");
$nodes = new \SplObjectStorage();
$ctr = 0;
foreach ($graph->vertices() as $vertex) {
$nodes[$vertex] = Node::create('node_' . $ctr++, (string) $vertex);
$new->setNode($nodes[$vertex]);
}
foreach ($graph->edges() as $edge) {
$new->link(Edge::create($nodes[$edge[0]], $nodes[$edge[1]]));
}
return $new;
}
/**
* Finds source vertices in a Digraph, then enqueues them.
*
* @param Digraph $graph
* @param DepthFirstVisitorInterface $visitor
*
* @return \SplQueue
*/
public static function find_sources(Digraph $graph, DepthFirstVisitorInterface $visitor)
{
$incomings = new \SplObjectStorage();
$queue = new \SplQueue();
foreach ($graph->edges() as $edge) {
if (!isset($incomings[$edge[1]])) {
$incomings[$edge[1]] = new \SplObjectStorage();
}
$incomings[$edge[1]]->attach($edge[0]);
}
// Prime the queue with vertices that have no incoming edges.
foreach ($graph->vertices() as $vertex) {
if (!$incomings->contains($vertex)) {
$queue->push($vertex);
$visitor->onInitializeVertex($vertex, TRUE, $queue);
} else {
$visitor->onInitializeVertex($vertex, FALSE, $queue);
}
}
return $queue;
}