Infinite loop issue

[Adraesh]

Hi,

The loop never ends.

$stream = new Stream\File($file, 1024);
$parser = new Parser\UniqueNode(array('uniqueNode' => $node));

$streamer = new XmlStringStreamer($parser, $stream);

while ($node = $streamer->getNode())
{
        //do some stuff...
}

Thank you in advance.

[prewk]

Hi! Can you provide some XML that causes the infinite loop?

It's kind of hard to debug otherwise, considering you've pasted code from the readme :)

[Adraesh]

Hi!

Of course, my bad...

You can try with those 2 XML: https://drive.google.com/open?id=0BxlGN-YBj-q0UmVYS01yNWc4OW8 https://drive.google.com/open?id=0BxlGN-YBj-q0b2RNaG1mOWtwYW8

Careful the second one is more that 1GB.

Thank you in advance.

[prewk]

Great, thank you! I'll look into it as soon as possible.

[prewk]

The small XML seems to work, are you having trouble with that one as well? I'm having problems with the larger one that I'll look into. The XML itself looks a bit odd.

What nodes are you interested in? I assumed <hasMember> when I tried it out.

This works for the small XML:

$stream = new Stream\File("small.xml", 1024);
$parser = new Parser\UniqueNode(array('uniqueNode' => "hasMember"));

$streamer = new XmlStringStreamer($parser, $stream);

$counter = 1;

while ($node = $streamer->getNode())
{
    preg_match('/gml:id="([a-z0-9.-]+)"/', $node, $matches);

    if (isset($matches[1])) {
        echo "$counter: $matches[1]\n";
    } else {
        echo "$counter: ?\n";
    }

    $counter++;
}

[Adraesh]

Hey!

Thank you for the fast review.

Yes I have trouble with the small xml as well.

Try a UniqueNode on the node: "aixm:AirportHeliport", you should have 4232 entries and arrived on the last item (4232) the loop seems to be stuck.

Thank you again.

EDIT: Obviously on "hasMember" node it is also working fine on my side. The problem could come from the namespace when I try to target the node "aixm:AirportHeliport" ?

[prewk]

I think I know why it has problems.. the UniqueNode parser is a bit prone to problems if you've got nodes with the same/similar names in different depths. (aixm:AirportHeliport, aixm:AirportHeliportCollocation)

Try out the StringWalker instead, it seems to work. I chose depth 2 here to represent AIXMBasicMessage > hasMember, you'll have to capture the aixm:AirportHeliport node out of the hasMember in some nifty way. Not all hasMember parent has aixm:AirportHeliport children (they're sometimes aixm:AirportHeliportCollocation).

$stream = new Stream\File("large.xml");
$parser = new Parser\StringWalker(array("captureDepth" => 2));

$streamer = new XmlStringStreamer($parser, $stream);

$counter = 1;

while ($node = $streamer->getNode())
{
    // Help SimpleXML with the namespaces
    $node = str_replace([
        "aixm:",
        "gml:",
        "gmd:",
        "gco:",
        "xlink:",
        "adr:",
        ], [
        "aixm_",
        "gml_",
        "gmd_",
        "gco_",
        "xlink_",
        "adr_",
    ], $node);
    $xml = simplexml_load_string($node);

    if ($xml->aixm_AirportHeliport) {
        echo "$counter " . $xml->aixm_AirportHeliport["gml_id"] . "\n";
    } else {
        echo "$counter\n";
    }

    $counter++;
}

[prewk]

^-After some revisions the code now works. It goes through 530958 hasMember nodes in the 1 GB XML and captures the gml:id attributes on the aixm:AirportHeliport nodes within them.

Note: Only a minority of the nodes in the XML contain a aixm:AirportHeliport node at all. A lot of them seem to contain aixm:AirportHeliportCollocation however.

[Adraesh]

Hey!

So what is the bottom line ? Should I keep my same code?

Thanks.

EDIT: Ok I see your previous code. Why are you replacing the namespace ? I need those namaspace remain the same as the deserialization process it's using it.

[prewk]

The namespace replacements are just a hacky way of getting SimpleXML to be able to read the nodes by themselves. The node is just an XML string, you can do what you want with it, I just wanted to show it was readable :)

[Adraesh]

I just tried with your code and it's working!

So in the mean time the solution for me was:

Using a StringWalker instead of the UniqueNode one.

Thank you very much !

[prewk]

No problem!

I've written an issue regarding the problem.

There is nothing wrong with using the StringWalker instead, it's just different (and a bit slower). It's a bit more resilient.