Alternative for slow PHP SimpleXmlElement cast to string - php

Question

Does anyone knows of an alternative to convert a SimpleXmlElement into a string?
The standard string casting is very slow:
$myString = (string)$simpleXmlElement->someNode;
I needed to know which one is faster for finding an element with a specific text-value: XPath or walking the nodes... So I wrote a simple script which would measure the duration of 1000 iterations for both ways.
The first results were that XPath was much slower, but then I found out that I forgot the string cast in the node-walking part. When I fixed that, the node-walking was much much slower.
So, only the cast-to-string flipped the entire outcome.
Please review the following code to understand the issue at hand:
<pre>
<?php
//---------------------------------------------------------------------------
date_default_timezone_set('Europe/Amsterdam');
error_reporting(E_ALL);
//---------------------------------------------------------------------------
$data = <<<'EOD'
<?xml version="1.0" encoding="UTF-8" ?>
<root>
<children>
<child><test>ads</test></child>
<child><test>sdf</test></child>
<child><test>dfg</test></child>
<child><test>fgh</test></child>
<child><test>ghj</test></child>
<child><test>hjk</test></child>
<child><test>jkl</test></child>
<child><test>ads</test></child>
<child><test>sdf</test></child>
<child><test>dfg</test></child>
<child><test>fgh</test></child>
<child><test>ghj</test></child>
<child><test>hjk</test></child>
<child><test>jkl</test></child>
<child><test>123</test></child>
<child><test>234</test></child>
<child><test>345</test></child>
<child><test>456</test></child>
<child><test>567</test></child>
<child><test>678</test></child>
<child><test>789</test></child>
<child><test>890</test></child>
<child><test>90-</test></child>
<child><test>0-=</test></child>
<child><test>qwe</test></child>
</children>
</root>
EOD;
$xml = new SimpleXMLElement($data);
$values = array('123', '234', '345', '456', '567', '678', '789', '890', '90-', '0-=', 'qwe');
$valCount = count($values);
$tries = 1000;
//---------------------------------------------------------------------------
echo("Running XPath... ");
$startTime = microtime(true);
for ($idx=0; $idx<$tries; $idx++)
$xml->xpath('/root/children/child[test="'.$values[($idx % $valCount)].'"]');
$duration = microtime(true) - $startTime;
echo("Finished in: $duration\r\n");
//---------------------------------------------------------------------------
echo("Running NodeWalk... ");
$startTime = microtime(true);
for ($idx=0; $idx<$tries; $idx++)
{
$nodes = $xml->children->child;
foreach ($nodes as $node)
if ((string)$node->test == $values[($idx % $valCount)])
break;
}
$duration = microtime(true) - $startTime;
echo("Finished in: $duration\r\n");
//---------------------------------------------------------------------------
?>
</pre>
When altering the line:
if ((string)$node->test == $values[($idx % $valCount)])
to:
if ($node->test == $values[($idx % $valCount)])
The code even looks at more nodes, but it's still a lot faster. So, it looks to me that the string cast here is very slow.
Does anyone have a faster alternative for the string cast?

Answer 1

Amazingly so, as #Gordon pointed out, there is actually not so much difference in performance... on Linux.
As the original tests were done only on Windows, I retested it on Linux, and what do you know... The difference between the XPath-way and the node-walking-way is gone.
For me that's enough, because I'm actually writing this for Linux (prod platform). But is still something to notice when building for Windows.