wp-wamr.php

<?php
/*
* Plugin Name: WAMR for Wordpress
* Description: WebAssembly Micro Runtime (WAMR) for Wordpress
* Version: 0.2
* Author: AsmNext Team
* Author URI: https://asmnext.com
*/

define( 'WP_WAMR_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );

function wp_wamr_exec($atts = array(), $content = null, $tag = '') {
    $result = "";

    $_atts = shortcode_atts(
        array(
            'packagename' => '',
            'filename' => 'test',
            'function' => '',
            'stacksize' => 0,
            'heapsize' => 0,
            'repl' => 'false',
            'env' => '',  // query string (e.g. 'key1=value1&key2=value2') 
            'dir' => '',   // comma sperated (e.g. '/mnt/wasi1,/mmt/wasi2')
            'args' => '',
            'benchmark' => 'false'
        ), $atts, $tag
    );

    // Path of 'iwasm' runtime
    // Source code: https://github.com/bytecodealliance/wasm-micro-runtime
    $wamr_bin_path = WP_WAMR_PLUGIN_DIR . 'bin/iwasm';

    // Build a command line
    $cmd = array();
    $is_tmpfile = false;

    if (file_exists($wamr_bin_path)) {
        array_push($cmd, $wamr_bin_path);

        if($_atts['stacksize'] > 0) {
            array_push($cmd, '--stack-size=' . $_atts['stacksize']);
        }

        if($_atts['heapsize'] > 0) {
            array_push($cmd, '--heap-size=' . $_atts['heapsize']);
        }

        if($_atts['repl'] == 'true') {
            array_push($cmd, '--repl');
        }

        if(!empty($_atts['env'])) {
            $_envs = explode('&', $_atts['env']);
            foreach($_envs as $_env) {
                array_push($cmd, '--env="' . addslashes($_env) . '"');
            }
        }

        if(!empty($_atts['dir'])) {
            $_dirs = explode(',', $_atts['dir']);
            foreach($_dirs as $_dir) {
                array_push($cmd, '--dir="' . addslashes($_dir) . '"');
            }
        }

        if(!empty($_atts['function'])) {
            array_push($cmd, '--function');
            array_push($cmd, $_atts['function']);   
        }

        // Path of WASM binary
        $filepath = wp_wamr_load_media($_atts['filename'], $_atts['packagename']);
        if (empty($filepath)) {
            $filepath = WP_WAMR_PLUGIN_DIR . 'wasm-bin/' . $_atts['filename'] . '.wasm';
        }
        array_push($cmd, $filepath);

        // Add arguments 
        if(!empty($_atts['args'])) {
            array_push($cmd, $_atts['args']);
        }

        // Build a command line
        $_cmd = implode(' ', $cmd);

        // Get stdout
        if($_atts['benchmark'] == 'true') {
            $ms = microtime(true);
            shell_exec($_cmd);
            $_ms = microtime(true);
            $result .= "[Benchmark] " . sprintf('%.8fs', ($_ms - $ms)) . " (WASM/Shell)";
        } else {
            $result .= shell_exec($_cmd);
        }
    } else {
        $result .= "[Error] WAMR not found!";
    }

    // Remove WASM file 
    $sys_tmpdir = sys_get_temp_dir();
    $targets = glob($sys_tmpdir . "/wp-wamr-*");
    foreach($targets as $target) {
        wp_wamr_clean($target);
    }

    return $result;
}

function wp_wamr_clean($target) {
    $_targets = glob("$target/*");
    foreach($_targets as $_target) {
        if (is_dir($_target)) {
            wp_wamr_clean($_target);
            rmdir($_target);
        } else {
            unlink($_target);
        }
    }
    rmdir($target);
}

function wp_wamr_benchmark() {
    $result = "";

    include_once(WP_WAMR_PLUGIN_DIR . 'benchmark/tower_of_hanoi.php');

    // Tower of Hanoi - 4 disks
    $result .= "<br>Tower of Hanoi - 4 disks";
    $ms = microtime(true);
    hanoi_move(4, 'A', 'B', 'C');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Native)";
    $ms = microtime(true);
    shell_exec('php ' . WP_WAMR_PLUGIN_DIR . 'benchmark/tower_of_hanoi_4disks');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Shell)";
    $result .= "<br>" . wp_wamr_exec(array('filename' => 'tower_of_hanoi_4disks.wasm', 'benchmark' => 'true'));
    $result .= "<br>";

    // Tower of Hanoi - 8 disks
    $result .= "<br>Tower of Hanoi - 8 disks";
    $ms = microtime(true);
    hanoi_move(8, 'A', 'B', 'C');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Native)";
    $ms = microtime(true);
    shell_exec('php ' . WP_WAMR_PLUGIN_DIR . 'benchmark/tower_of_hanoi_8disks');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Shell)";
    $result .= "<br>" . wp_wamr_exec(array('filename' => 'tower_of_hanoi_8disks', 'benchmark' => 'true'));
    $result .= "<br>";

    // Tower of Hanoi - 16 disks
    $result .= "<br>Tower of Hanoi - 16 disks";
    $ms = microtime(true);
    hanoi_move(16, 'A', 'B', 'C');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Native)";
    $ms = microtime(true);
    shell_exec('php ' . WP_WAMR_PLUGIN_DIR . 'benchmark/tower_of_hanoi_16disks.php');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Shell)";
    $result .= "<br>" . wp_wamr_exec(array('filename' => 'tower_of_hanoi_16disks', 'benchmark' => 'true'));
    $result .= "<br>";

    // Tower of Hanoi - 20 disks
    $result .= "<br>Tower of Hanoi - 20 disks";
    $ms = microtime(true);
    hanoi_move(20, 'A', 'B', 'C');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Native)";
    $ms = microtime(true);
    shell_exec('php ' . WP_WAMR_PLUGIN_DIR . 'benchmark/tower_of_hanoi_20disks.php');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Shell)";
    $result .= "<br>" . wp_wamr_exec(array('filename' => 'tower_of_hanoi_20disks', 'benchmark' => 'true'));
    $result .= "<br>";

    // Tower of Hanoi - 24 disks
    $result .= "<br>Tower of Hanoi - 24 disks";
    $ms = microtime(true);
    hanoi_move(24, 'A', 'B', 'C');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Native)";
    $ms = microtime(true);
    shell_exec('php ' . WP_WAMR_PLUGIN_DIR . 'benchmark/tower_of_hanoi_24disks.php');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Shell)";
    $result .= "<br>" . wp_wamr_exec(array('filename' => 'tower_of_hanoi_24disks', 'benchmark' => 'true'));
    $result .= "<br>";

    // Tower of Hanoi - 28 disks
    $result .= "<br>Tower of Hanoi - 28 disks";
    $ms = microtime(true);
    hanoi_move(28, 'A', 'B', 'C');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Native)";
    $ms = microtime(true);
    shell_exec('php ' . WP_WAMR_PLUGIN_DIR . 'benchmark/tower_of_hanoi_28disks.php');
    $_ms = microtime(true);
    $result .= "<br>" . sprintf('%.8fs', ($_ms - $ms)) . " (PHP/Shell)";
    $result .= "<br>" . wp_wamr_exec(array('filename' => 'tower_of_hanoi_28disks', 'benchmark' => 'true'));
    $result .= "<br>";

    return $result;
}

function wp_wamr_verify_checksum($basedir, $filename) {
    // Check exists target file
    $filepath = $basedir . '/' . $filename . '.wasm';
    if (!file_exists($filepath)) {
        echo "[Error] Does not exists target file";
    }

    // Check exists MD5SUM file
    $checksum_index = -1;
    $checksum_file = '';
    $checksum_possibles = array(
        $basedir . '/MD5SUM',
        $basedir . '/md5sum',
        $basedir . '/SHA1SUM',
        $basedir . '/sha1sum'
    );
    for ($i = 0; $i < count($checksum_possibles); $i++) {
        if (file_exists($checksum_possibles[$i])) {
            $checksum_index = $i;
            $checksum_file = $checksum_possibles[$checksum_index];
            break;
        }
    }

    // If could not find
    if ($hashinfo_index < 0) {
        echo "[Error] Does not exists the checksum file";
        return false;
    }

    // Open the MD5SUM file
    $contents = fread(fopen($checksum_file, 'r'), filesize($checksum_file));

    // Parse MD5SUM contents
    $segments = preg_split('/[\s]+/', $contents);

    // Calcuate file hash
    $checksum = '';
    if (strpos(strtoupper($checksum_file), "MD5SUM") !== false) {
        $checksum = md5_file($filepath);
    } else if (strpos(strtoupper($checksum_file), "SHA1SUM") !== false) {
        $checksum = sha1_file($filepath);
    }

    // Is it verified?
    return !empty($checksum) ? in_array($checksum, $segments) : false;
}

function wp_wamr_load_media($filename, $packagename) {
    global $wpdb;

    $old_filepath = "";
    $filepath = "";

    // The following code is used to retrieve and store the site URL in the variable $site_url. 
    // This URL is the root URL of the WordPress site, which is essential for building paths or links relative to the site's base.
    //
    // REAL PATH: /var/www/html/wordpress/wp-content/plugins
    // The directory path provided here represents the actual file system path where the WordPress plugins are stored.
    //
    // It's important to understand that the real path may differ from the site's URL. The real path refers to the location on the server's filesystem,
    // while the URL (provided by site_url()) is what users access via their web browsers.
    //
    // To ensure consistency between the URL and the server's file structure, the following line of code retrieves the document root directory of the server,
    // appends '/wordpress' to it, and assigns it to the $docroot variable.
    //
    // $docroot will store the full absolute path to the root of the WordPress installation on the server, 
    // which is necessary for performing file operations or linking resources correctly.
    //
    // Note: The realpath() function is used to resolve any symbolic links, '..' or '.' in the path, ensuring that $docroot contains the correct and absolute path.
    $site_url = site_url();
    $docroot = realpath($_SERVER["DOCUMENT_ROOT"]) . '/wordpress'; // ends with a slash (/) + '/wordpress'

    $sys_tmpdir = sys_get_temp_dir();
    $tmpdir = $sys_tmpdir . '/wp-wamr-' . substr(md5(mt_rand()), 0, 7);

    if(mkdir($tmpdir)) {
        $results = $wpdb->get_results( "select guid from {$wpdb->prefix}posts
             where post_type = 'attachment' and post_title = '{$packagename}'
             order by post_date desc limit 1" , OBJECT );
        foreach($results as $attachment) {
            if ($site_url == substr($attachment->guid, 0, strlen($site_url))) {
                $old_filepath = $docroot . substr($attachment->guid, strlen($site_url));
            }
        }

        // For security reason, the media file must be compressed like '*.zip'
        if (!empty($old_filepath) && file_exists($old_filepath)) {
            $zip = new ZipArchive();
            $result = $zip->open($old_filepath);
            if ($result === TRUE) {
                $zip->extractTo($tmpdir . '/');
                $zip->close();

                $_filepath = $tmpdir . '/' . $filename . '.wasm';
                if(file_exists($_filepath) && wp_wamr_verify_checksum($tmpdir, $filename)) {
                    $filepath = $_filepath;
                } else {
                    echo "[Error] Failed to verify the checksum of WASM file";
                }
            } else {
                echo "[Error] Invaild package file";
            }
        } else {
            echo "[Error] No exists package file in Media Library";
        }
    }

    return $filepath;
}

add_shortcode('wamr_exec', 'wp_wamr_exec');
add_shortcode('wamr_benchmark', 'wp_wamr_benchmark');