hestiacp/web/inc/2fa/loader.php

<?php

//http://www.leaseweblabs.com/2014/04/psr-0-psr-4-autoloading-classes-php/
class Loader {
	protected static $parentPath = null;
	protected static $paths = null;
	protected static $files = null;
	protected static $nsChar = "\\";
	protected static $initialized = false;

	protected static function initialize() {
		if (static::$initialized) {
			return;
		}
		static::$initialized = true;
		static::$parentPath = __FILE__;
		for ($i = substr_count(get_class(), static::$nsChar); $i >= 0; $i--) {
			static::$parentPath = dirname(static::$parentPath);
		}
		static::$paths = [];
		static::$files = [__FILE__];
	}

	public static function register($path, $namespace) {
		if (!static::$initialized) {
			static::initialize();
		}
		static::$paths[$namespace] = trim($path, DIRECTORY_SEPARATOR);
	}

	public static function load($class) {
		if (class_exists($class, false)) {
			return;
		}
		if (!static::$initialized) {
			static::initialize();
		}

		foreach (static::$paths as $namespace => $path) {
			if (
				!$namespace ||
				$namespace . static::$nsChar ===
					substr($class, 0, strlen($namespace . static::$nsChar))
			) {
				$fileName = substr($class, strlen($namespace . static::$nsChar) - 1);
				$fileName = str_replace(
					static::$nsChar,
					DIRECTORY_SEPARATOR,
					ltrim($fileName, static::$nsChar),
				);
				$fileName =
					static::$parentPath .
					DIRECTORY_SEPARATOR .
					$path .
					DIRECTORY_SEPARATOR .
					$fileName .
					".php";

				if (file_exists($fileName)) {
					include $fileName;
					return true;
				}
			}
		}
		return false;
	}
}

spl_autoload_register(["Loader", "load"]);