Proyectos de Subversion Moodle

<?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/>.

/**

 * This file is serving optimised JS and WASM for ogv.js.

 *

 * @package media_videojs

 * @copyright 2021 Huong Nguyen <huongnv13@gmail.com>

 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

// Disable moodle specific debug messages and any errors in output,

// comment out when debugging or better look into error log!

define('NO_DEBUG_DISPLAY', true);

// We need just the values from config.php and minlib.php.

define('ABORT_AFTER_CONFIG', true);

require_once('../../../config.php'); // This stops immediately at the beginning of lib/setup.php.

require_once($CFG->dirroot . '/lib/jslib.php');

require_once($CFG->dirroot . '/lib/wasmlib.php');

$slashargument = min_get_slash_argument();

if (!$slashargument) {

    // The above call to min_get_slash_argument should always work.

    die('Invalid request');

}

$slashargument = ltrim($slashargument, '/');

if (substr_count($slashargument, '/') < 1) {

    header('HTTP/1.0 404 not found');

    die('Slash argument must contain both a revision and a file path');

}

// Get all the library files (js and wasm) of the OGV.

$basepath = $CFG->dirroot . '/media/player/videojs/ogvjs/';

$jsfiles = [];

$files = glob("{$basepath}*.{js,wasm}", GLOB_BRACE);

foreach ($files as $file) {

    $jsfiles[] = basename($file);

}

// Split into revision and module name.

list($rev, $file) = explode('/', $slashargument, 2);

$rev  = min_clean_param($rev, 'INT');

$file = min_clean_param($file, 'SAFEPATH');

if (empty($jsfiles) || !in_array($file, $jsfiles)) {

    // We can't find the requested file.

    header('HTTP/1.0 404 not found');

    exit(0);

}

// Check if the requesting file is Javascript or Web Assembly.

$iswasm = media_videojs_ogvloader_is_wasm_file($file);

// Use the caching only for meaningful revision numbers which prevents future cache poisoning.

if ($rev > 0 and $rev < (time() + 60 * 60)) {

    // We are lazy loading a single file - so include the filename in the etag.

    $etag = sha1($rev . '/' . $file);

    $candidate = $CFG->localcachedir . '/ogvloader/' . $etag;

    if (file_exists($candidate)) {

        // Cache exist.

        if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {

            // We do not actually need to verify the etag value because our files

            // never change in cache because we increment the rev parameter.

            media_videojs_ogvloader_send_unmodified($iswasm, $candidate, $etag);

        }

        media_videojs_ogvloader_send_cached($iswasm, $candidate, $etag);

        exit(0);

    } else {

        // Cache does not exist. Create one.

        $filecontent = file_get_contents($basepath . $file);

        if ($filecontent === false) {

            error_log('Failed to load the library ' . $file);

            $filecontent = "/* Failed to load library file {$file}. */\n";

        }

        $filecontent = media_videojs_ogvloader_add_module_module_name_if_necessary($iswasm, $filecontent);

        media_videojs_ogvloader_write_cache_file_content($iswasm, $candidate, $filecontent);

        // Verify nothing failed in cache file creation.

        clearstatcache();

        if (file_exists($candidate)) {

            media_videojs_ogvloader_send_cached($iswasm, $candidate, $etag);

            exit(0);

        }

    }

}

// If we've made it here then we're in "dev mode" where everything is lazy loaded.

// So all files will be served one at a time.

$filecontent = file_get_contents($basepath . $file);

$filecontent = rtrim($filecontent);

$filecontent = media_videojs_ogvloader_add_module_module_name_if_necessary($iswasm, $filecontent);

media_videojs_ogvloader_send_uncached($iswasm, $filecontent);

/**

 * Check the given file is a Web Assembly file or not

 *

 * @param string $filename File name to check

 * @return bool Whether the file is Web Assembly or not

 */

function media_videojs_ogvloader_is_wasm_file(string $filename): bool {

    $ext = pathinfo($filename, PATHINFO_EXTENSION);

    return $ext == 'wasm';

}

/**

 * Add Moodle module name to the Javascript module if necessary

 *

 * @param bool $iswasm Whether the file is Web Assembly or not

 * @param string $content File content

 * @return string

 */

function media_videojs_ogvloader_add_module_module_name_if_necessary(bool $iswasm, string $content): string {

    if (!$iswasm && preg_match('/define\(\s*(\[|function)/', $content)) {

        // If the JavaScript module has been defined without specifying a name then we'll

        // add the Moodle module name now.

        $replace = 'define(\'media_videojs/video-lazy\', ';

        $search = 'define(';

        // Replace only the first occurrence.

        $content = implode($replace, explode($search, $content, 2));

    }

    return $content;

}

/**

 * Create cache file content

 *

 * @param bool $iswasm Whether the file is Web Assembly or not

 * @param string $candidate Full file path to cache file

 * @param string $filecontent File content

 */

function media_videojs_ogvloader_write_cache_file_content(bool $iswasm, string $candidate, string $filecontent): void {

    $iswasm ? wasm_write_cache_file_content($candidate, $filecontent) : js_write_cache_file_content($candidate, $filecontent);

}

/**

 * Send file content with as much caching as possible

 *

 * @param bool $iswasm Whether the file is Web Assembly or not

 * @param string $candidate Full file path to cache file

 * @param string $etag Etag

 */

function media_videojs_ogvloader_send_cached(bool $iswasm, string $candidate, string $etag): void {

    $iswasm ? wasm_send_cached($candidate, $etag, 'ogvloader.php') : js_send_cached($candidate, $etag, 'ogvloader.php');

}

/**

 * Send file without any caching

 *

 * @param bool $iswasm Whether the file is Web Assembly or not

 * @param string $ilecontent File content

 */

function media_videojs_ogvloader_send_uncached(bool $iswasm, string $ilecontent): void {

    $iswasm ? wasm_send_uncached($ilecontent, 'ogvloader.php') : js_send_uncached($ilecontent, 'ogvloader.php');

}

/**

 * Send the file not modified headers

 *

 * @param bool $iswasm Whether the file is Web Assembly or not

 * @param int $candidate Full file path to cache file

 * @param string $etag Etag

 */

function media_videojs_ogvloader_send_unmodified(bool $iswasm, int $candidate, string $etag): void {

    $iswasm ? wasm_send_unmodified(filemtime($candidate), $etag) : js_send_unmodified(filemtime($candidate), $etag);

}