Merge branch 'MDL-65943-311' of git://github.com/HuongNV13/moodle int…

…o MOODLE_311_STABLE

lib/wasmlib.php

@@ -0,0 +1,129 @@
+<?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 contains various Web Assembly related functions,
+ * all functions here are self-contained and can be used in ABORT_AFTER_CONFIG scripts.
+ *
+ * @package core_lib
+ * @copyright 2021 Huong Nguyen <huongnv13@gmail.com>
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Send Web Assembly file content with as much caching as possible
+ *
+ * @param string $wasmpath Path to Web Assembly file
+ * @param string $etag Etag
+ * @param string $filename File name to be served
+ */
+function wasm_send_cached(string $wasmpath, string $etag, string $filename = 'wasm.php'): void {
+    require(__DIR__ . '/xsendfilelib.php');
+
+    // 90 days only - based on Moodle point release cadence being every 3 months.
+    $lifetime = 60 * 60 * 24 * 90;
+
+    header('Etag: "' . $etag . '"');
+    header('Content-Disposition: inline; filename="' . $filename . '"');
+    header('Last-Modified: ' . gmdate('D, d M Y H:i:s', filemtime($wasmpath)) . ' GMT');
+    header('Expires: ' . gmdate('D, d M Y H:i:s', time() + $lifetime) . ' GMT');
+    header('Pragma: ');
+    header('Cache-Control: public, max-age=' . $lifetime . ', immutable');
+    header('Accept-Ranges: none');
+    header('Content-Type: application/wasm');
+
+    if (xsendfile($wasmpath)) {
+        die;
+    }
+
+    if (!min_enable_zlib_compression()) {
+        header('Content-Length: ' . filesize($wasmpath));
+    }
+
+    readfile($wasmpath);
+    die;
+}
+
+/**
+ * Send Web Assembly file without any caching
+ *
+ * @param string $wasm Web Assembly file content
+ * @param string $filename File name to be served
+ */
+function wasm_send_uncached(string $wasm, string $filename = 'wasm.php'): void {
+    header('Content-Disposition: inline; filename="' . $filename . '"');
+    header('Last-Modified: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');
+    header('Expires: ' . gmdate('D, d M Y H:i:s', time() + 2) . ' GMT');
+    header('Pragma: ');
+    header('Accept-Ranges: none');
+    header('Content-Type: application/wasm');
+    header('Content-Length: ' . strlen($wasm));
+
+    echo $wasm;
+    die;
+}
+
+/**
+ * Send Web Assembly file not modified headers
+ *
+ * @param int $lastmodified Last modified timestamp
+ * @param string $etag Etag
+ */
+function wasm_send_unmodified(int $lastmodified, string $etag): void {
+    // 90 days only - based on Moodle point release cadence being every 3 months.
+    $lifetime = 60 * 60 * 24 * 90;
+    header('HTTP/1.1 304 Not Modified');
+    header('Expires: ' . gmdate('D, d M Y H:i:s', time() + $lifetime) . ' GMT');
+    header('Cache-Control: public, max-age=' . $lifetime);
+    header('Content-Type: application/wasm');
+    header('Etag: "' . $etag . '"');
+    if ($lastmodified) {
+        header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $lastmodified) . ' GMT');
+    }
+    die;
+}
+
+/**
+ * Create cache file for Web Assembly content
+ *
+ * @param string $file full file path to cache file
+ * @param string $content Web Assembly content
+ */
+function wasm_write_cache_file_content(string $file, string $content): void {
+    global $CFG;
+
+    clearstatcache();
+    if (!file_exists(dirname($file))) {
+        @mkdir(dirname($file), $CFG->directorypermissions, true);
+    }
+
+    // Prevent serving of incomplete file from concurrent request,
+    // the rename() should be more atomic than fwrite().
+    ignore_user_abort(true);
+    if ($fp = fopen($file . '.tmp', 'xb')) {
+        fwrite($fp, $content);
+        fclose($fp);
+        rename($file . '.tmp', $file);
+        @chmod($file, $CFG->filepermissions);
+        @unlink($file . '.tmp'); // Just in case anything fails.
+    }
+    ignore_user_abort(false);
+    if (connection_aborted()) {
+        die;
+    }
+}