Range Download – Usage: wire('modules')->get('ProcessPageView')->sendFile($page, $filename);

RangeDownloadBoss.module.php

<?php

/**
 * © noelboss.com
 *
 * This source file is subject to the license file that is bundled
 * with this source code in the file LICENSE.
 *
 * File created/changed: 2018-06-21T16:24:02+02:00
 */

namespace ProcessWire;

/*
 * This _init.php file is called automatically by ProcessWire before every page render.
 */
class RangeDownloadBoss extends WireData implements Module
{
	/**
	 * getModuleInfo is a module required by all modules to tell ProcessWire about them.
	 *
	 * @return array
	 */
	public static function getModuleInfo()
	{
		return [
			// The module'ss title, typically a little more descriptive than the class name
			'title' => 'Range Download Boss',

			// version number
			'version' => '0.0.1',

			// summary is brief description of what this module is
			'summary' => 'Adds range downloads for videos etc.',

			// Optional URL to more information about the module
			'href' => '',

			// singular=true: indicates that only one instance of the module is allowed.
			// This is usually what you want for modules that attach hooks.
			'singular' => true,

			// autoload=true: indicates the module should be started with ProcessWire.
			// This is necessary for any modules that attach runtime hooks, otherwise those
			// hooks won't get attached unless some other code calls the module on it's own.
			// Note that autoload modules are almost always also 'singular' (seen above).
			'autoload' => true,

			// Optional font-awesome icon name, minus the 'fa-' part
			'icon' => 'download',
		];
	}

	public function init()
	{
		wire()->addHookBefore('ProcessPageView::sendFile', $this, 'sendFileHook');
	}

	public function sendFileHook(HookEvent $event)
	{
		$page = $event->arguments[0];

		$file;

		if ($page->hasField('files')) {
			$file = $page->files->get($event->arguments[1]);
		} elseif ($page->hasField('image')) {
			$file = $page->image->get($event->arguments[1]);
		}

		if (!$file instanceof Pagefile && !$file instanceof Pageimage) {
			return;
		}

		$this->downloadRange($file);
	}

	/**
	 * Send a File as Range.
	 *
	 * @param HookEvent $event
	 * @param mixed     $file
	 */
	private function downloadRange($file)
	{
		if (!is_file($file->filename)) {
			throw new Wire404Exception('Page not found');
		}

		$fp = @fopen($file->filename, 'rb');
		$size = filesize($file->filename); // File size
		$length = $size;		   // Content length
		$start = 0;			   // Start byte
		$end = $size - 1;	   // End byte

		if (isset(wire('config')->fileContentTypes[$file->ext])) {
			$ctype = wire('config')->fileContentTypes[$file->ext];
		} else {
			$ctype = mime_content_type($file->filename);
		}

		header('Content-type: '.$ctype);
		header("Accept-Ranges: 0-$length");

		if (isset($_SERVER['HTTP_RANGE'])) {
			$c_start = $start;
			$c_end = $end;
			list(, $range) = explode('=', $_SERVER['HTTP_RANGE'], 2);
			if (strpos($range, ',') !== false) {
				header('HTTP/1.1 416 Requested Range Not Satisfiable');
				header("Content-Range: bytes $start-$end/$size");
				exit;
			}
			if ($range == '-') {
				$c_start = $size - substr($range, 1);
			} else {
				$range = explode('-', $range);
				$c_start = $range[0];
				$c_end = (isset($range[1]) && is_numeric($range[1])) ? $range[1] : $size;
			}
			$c_end = ($c_end > $end) ? $end : $c_end;
			if ($c_start > $c_end || $c_start > $size - 1 || $c_end >= $size) {
				header('HTTP/1.1 416 Requested Range Not Satisfiable');
				header("Content-Range: bytes $start-$end/$size");
				exit;
			}
			$start = $c_start;
			$end = $c_end;
			$length = $end - $start + 1;
			fseek($fp, $start);
			header('HTTP/1.1 206 Partial Content');
		}
		header("Content-Range: bytes $start-$end/$size");
		header('Content-Length: '.$length);
		$buffer = 1024 * 8;
		while (!feof($fp) && ($p = ftell($fp)) <= $end) {
			if ($p + $buffer > $end) {
				$buffer = $end - $p + 1;
			}
			set_time_limit(0);
			echo fread($fp, $buffer);
			flush();
		}
		fclose($fp);
		exit();
	}
}