fontoxpath/test/specs/parsing/performance-regression.tests.js

A minimalistic XPath 3.1 engine in JavaScript

import { evaluateXPathToFirstNode, evaluateXPathToNodes, evaluateXPathToBoolean } from 'fontoxpath';
import * as slimdom from 'slimdom';

import xqString from 'text-loader!./performance-regression.xq';

const cacheId = {};

function timeXPath (xpath, document) {
	const then = performance.now();
	chai.assert(evaluateXPathToBoolean(xpath, document), `The passed XPath ${xpath} should resolve to true`);
	const now =  performance.now();
	return now - then;
}

function fillDocument (document, element, depth) {
	element.setAttribute('depth', depth);
	if (depth === 0) {
		return element;
	}
	var prototypeElement = element.appendChild(
		fillDocument(
			document,
			document.createElement('ele'),
			depth - 1));

	for (let i = 1, l = 10; i < l; ++i) {
		element.appendChild(prototypeElement.cloneNode(true));
	}
	return element;
}
function runTests (document) {
	const element = evaluateXPathToFirstNode(xqString, document, null, null, { language: 'XQuery3.1' });
	const cells = evaluateXPathToNodes('descendant::entry', element);
	before(function () {
		this.timeout(30000);
	});

	it('Makes queries exit early by streaming them and only consuming the first item', function () {
		this.timeout(10000);
		for (var i = 0; i < 100; ++i) {
			const times = cells.map(cell => timeXPath('"let $colname := ./@colname, $namest      := ./@namest, $nameend     := ./@nameend, $startindex  := ./ancestor::Q{}tgroup[1]/Q{}colspec[@colname = $namest]/preceding-sibling::Q{}colspec => count() + 1, $endindex    := ./ancestor::Q{}tgroup[1]/Q{}colspec[@colname = $nameend]/preceding-sibling::Q{}colspec => count() + 1 return if ($colname and not($namest or $nameend)) then 1 else ($endindex - $startindex) + 1"', cell));

		console.log(times.reduce((sum, time) => sum + time, 0) / times.length);

		}
	});
}

describe('performance regression of 2.8.0', () => {
	describe('in slimdom', () => runTests(new slimdom.Document()));
});