Online PHP editor | refs for 1fFB3

<?php /** * This code demonstrates the performance difference when calling * DOMElement::C14N() on generated DOMDocument versus on a DOMDocument that was * loaded from a string. * * Calling DOMDocument::normalizeDocument() doesn't make any difference. * * Output example: * Testing with 500 items * Native DOM (not normalized)… 2.55357 seconds * Native DOM (normalized)… 2.52199 seconds * Export and re-import DOM… 0.06444 seconds */ define('NUMBER_OF_ITEMS', 200); define('XML_NAME_SPACE', 'http://example.com/xml'); echo sprintf('Testing with %d items', NUMBER_OF_ITEMS) . PHP_EOL; echo 'Generated DOM… '; $nativeDOM = generate_random_dom(); $s = microtime(true); iterate_with_xpath($nativeDOM); echo number_format(microtime(true) - $s, 5) . ' seconds' . PHP_EOL; echo 'Generated DOM with normalizeDocument()… '; $nativeDOMNormalized = generate_random_dom(); $s = microtime(true); $nativeDOMNormalized->normalizeDocument(); iterate_with_xpath($nativeDOMNormalized); echo number_format(microtime(true) - $s, 5) . ' seconds' . PHP_EOL; echo 'Export and re-import DOM… '; $dom3 = generate_random_dom(); $s = microtime(true); $importedXmlString = new \DOMDocument('1.0', 'UTF-8'); $importedXmlString->loadXML($dom3->saveXML()); iterate_with_xpath($importedXmlString); echo number_format(microtime(true) - $s, 5) . ' seconds' . PHP_EOL; /** * Iterate over items' content and call C14N * * @param \DOMDocument $dom */ function iterate_with_xpath(\DOMDocument $dom): void { $xpath = new \DOMXPath($dom); $xpath->registerNamespace('listElement', XML_NAME_SPACE); /** @var \DOMElement $item */ foreach($xpath->query('//listElement:alpha', null, XML_NAME_SPACE) as $item) { $item->C14N(); } } /** * Generate random DOMDocument * * Example: * <listElement> * <listItem index="0"> * <alpha>random value here</alpha> * </listItem> * ... * </listElement> * * @return \DOMDocument */ function generate_random_dom(): \DOMDocument { $dom = new \DOMDocument(); $dom->formatOutput = true; /** @var \DOMElement $list */ $list = $dom->createElementNS(XML_NAME_SPACE, 'listElement'); $dom->appendChild($list); for($i = 0; $i < NUMBER_OF_ITEMS; $i++) { /** @var \DOMElement $listItem */ $listItem = $dom->createElementNS(XML_NAME_SPACE, 'listItem'); $listItem->setAttribute('index', $i); $list->appendChild($listItem); $subElement = $dom->createElementNS(XML_NAME_SPACE, 'alpha'); $subElement->appendChild($dom->createTextNode(uniqid('a', true))); $listItem->appendChild($subElement); } return $dom; }