compresscheck.php

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Performs a compression test
 *
 * @package    tool_heartbeat
 * @copyright  2017 Rossco Hellmans <rossco@catalyst-au.net>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

require(__DIR__ . '/../../../config.php');

$syscontext = context_system::instance();
$PAGE->set_url('/admin/tool/heartbeat/compresscheck.php');
$PAGE->set_context($syscontext);
$PAGE->set_cacheable(false);

$ttfb = optional_param('ttfb', 1, PARAM_INT);
// Default fixed size is 50KB.
$fixedsize = optional_param('fixedsize', 51200, PARAM_INT);

// Max fixed size is 500KB in case of a ddos vector.
if ($fixedsize > 512000) {
    $fixedsize = 512000;
}

sleep($ttfb);

$string = '';

for ($i = 0; $i < $fixedsize; $i++) {
    $string .= '.';
}

echo $string;