+<?php

+

+/**

+ * This is a slightly strange file. It is not designed to ever be run directly from within SMF's

+ * conventional running, but called externally to facilitate background tasks. It can be called

+ * either directly or via cron, and in either case will completely ignore anything supplied

+ * via command line, or $_GET, $_POST, $_COOKIE etc. because those things should never affect the

+ * running of this script.

+ *

+ * Because of the way this runs, etc. we do need some of SMF but not everything to try to keep this

+ * running a little bit faster.

+ *

+ * Simple Machines Forum (SMF)

+ *

+ * @package SMF

+ * @author Simple Machines http://www.simplemachines.org

+ * @copyright 2013 Simple Machines and individual contributors

+ * @license http://www.simplemachines.org/about/smf/license.php BSD

+ *

+ * @version 2.1 Alpha 1

+ */

+

+define('SMF', 'BACKGROUND');

+define('FROM_CLI', defined('STDIN'));

+define('WIRELESS', false);

+

+// This one setting is worth bearing in mind. If you are running this from proper cron, make sure you

+// don't run this file any more frequently than indicated here. It might turn ugly if you do.

+// But on proper cron you can always increase this value provided you don't go beyond max_limit.

+define('MAX_CRON_TIME', 10);

+// If a task fails for whatever reason it will still be marked as claimed. This is the threshold

+// by which if a task has not completed in this time, the task should become available again.

+define('MAX_CLAIM_THRESHOLD', 300);

+

+// We're going to want a few globals... these are all set later.

+global $time_start, $maintenance, $msubject, $mmessage, $mbname, $language;

+global $boardurl, $boarddir, $sourcedir, $webmaster_email;

+global $db_server, $db_name, $db_user, $db_prefix, $db_persist, $db_error_send, $db_last_error;

+global $db_connection, $modSettings, $context, $sc, $user_info, $txt;

+global $smcFunc, $ssi_db_user, $scripturl, $db_passwd, $cachedir;

+

+define('TIME_START', microtime(true));

+

+// Just being safe...

+foreach (array('db_character_set', 'cachedir') as $variable)

+	if (isset($GLOBALS[$variable]))

+		unset($GLOBALS[$variable]);

+

+// Get the forum's settings for database and file paths.

+require_once(dirname(__FILE__) . '/Settings.php');

+

+// Make absolutely sure the cache directory is defined.

+if ((empty($cachedir) || !file_exists($cachedir)) && file_exists($boarddir . '/cache'))

+	$cachedir = $boarddir . '/cache';

+

+// Don't do john didley if the forum's been shut down competely.

+if ($maintenance == 2)

+	die($mmessage);

+

+// Fix for using the current directory as a path.

+if (substr($sourcedir, 0, 1) == '.' && substr($sourcedir, 1, 1) != '.')

+	$sourcedir = dirname(__FILE__) . substr($sourcedir, 1);

+

+// Have we already turned this off? If so, exist gracefully.

+if (file_exists($cachedir . '/cron.lock'))

+	obExit_cron();

+

+// Load the most important includes. In general, a background should be loading its own dependencies.

+require_once($sourcedir . '/Errors.php');

+require_once($sourcedir . '/Load.php');

+require_once($sourcedir . '/Subs.php');

+

+// Using an pre-PHP 5.1 version?

+if (version_compare(PHP_VERSION, '5.1', '<'))

+	require_once($sourcedir . '/Subs-Compat.php');

+

+// Create a variable to store some SMF specific functions in.

+$smcFunc = array();

+

+// This is our general bootstrap, a la SSI.php but with a few differences.

+loadDatabase();

+reloadSettings();

+

+// Just in case there's a problem...

+set_error_handler('error_handler_cron');

+$sc = 'n/a';

+

+// Now 'clean the request' (or more accurately, ignore everything we're not going to use)

+cleanRequest_cron();

+

+// At this point we could reseed the RNG but I don't think we need to risk it being seeded *even more*.

+// Meanwhile, time we got on with the real business here.

+while ($task_details = fetch_task())

+{

+	$result = perform_task($task_details);

+	if ($result)

+	{

+		$smcFunc['db_query']('', '

+			DELETE FROM {db_prefix}background_tasks

+			WHERE id_task = {int:task}',

+			array(

+				'task' => $task_details['id_task'],

+			)

+		);

+	}

+}

+exit;

+

+// The heart of this cron handler...

+

+function fetch_task()

+{

+	global $smcFunc;

+

+	// Check we haven't run over our time limit.

+	if (microtime(true) - TIME_START > MAX_CRON_TIME)

+		return false;

+

+	// Try to find a task. Specifically, try to find one that hasn't been claimed previously, or failing that,

+	// a task that was claimed but failed for whatever reason and failed long enough ago. We should not care

+	// what task it is, merely that it is one in the queue, the order is irrelevant.

+	$request = $smcFunc['db_query']('', '

+		SELECT id_task, task_file, task_class, task_data, claimed_time

+		FROM {db_prefix}background_tasks

+		WHERE claimed_time < {int:claim_limit}

+		ORDER BY null

+		LIMIT 1',

+		array(

+			'claim_limit' => time() - MAX_CLAIM_THRESHOLD,

+		)

+	);

+	if ($row = $smcFunc['db_fetch_assoc']($request))

+	{

+		// We found one. Let's try and claim it immediately.

+		$smcFunc['db_free_result']($request);

+		$smcFunc['db_query']('', '

+			UPDATE {db_prefix}background_tasks

+			SET claimed_time = {int:new_claimed}

+			WHERE id_task = {int:task}

+				AND claimed_time = {int:old_claimed}',

+			array(

+				'new_claimed' => time(),

+				'task' => $row['id_task'],

+				'old_claimed' => $row['claimed_time'],

+			)

+		);

+		// Could we claim it? If so, return it back.

+		if ($smcFunc['db_affected_rows']() != 0)

+		{

+			// Update the time and go back.

+			$row['claimed_time'] = time();

+			return $row;

+		}

+		else

+		{

+			// Uh oh, we just missed it. Try to claim another one, and let it fall through if there aren't any.

+			return fetch_task();

+		}

+	}

+	else

+	{

+		// No dice. Clean up and go home.

+		$smcFunc['db_free_result']($request);

+		return false;

+	}

+}

+

+function perform_task($task_details)

+{

+	global $sourcedir, $boarddir;

+

+	// This indicates the file to load.

+	if (!empty($task_details['task_file']))

+	{

+		$include = strtr(trim($task_details['task_file']), array('$boarddir' => $boarddir, '$sourcedir' => $sourcedir));

+		if (file_exists($include))

+			require_once($include);

+	}

+

+	if (empty($task_details['task_class']))

+	{

+		// This would be nice to translate but the language files aren't loaded for any specific language.

+		log_error('Invalid background task specified (no class, ' . (empty($task_details['task_file']) ? ' no file' : ' to load ' . $task_details['task_file']) . ')');

+		return true; // So we clear it from the queue.

+	}

+

+	// All background tasks need to be classes.

+	elseif (class_exists($task_details['task_class']) && is_subclass_of($task_details['task_class'], 'SMF_BackgroundTask'))

+	{

+		$bgtask = new $task_details['task_class'];

+		$bgtask->setDetails($details);

+		return $bgtask->execute();

+	}

+	else

+	{

+		log_error('Invalid background task specified: (class: ' . $task_details['task_class'] . ', ' . (empty($task_details['task_file']) ? ' no file' : ' to load ' . $task_details['task_file']) . ')');

+		return true; // So we clear it from the queue.

+	}

+}

+

+// These are all our helper functions that resemble their big brother counterparts. These are not so important.

+function cleanRequest_cron()

+{

+	global $scripturl, $boardurl;

+

+	$scripturl = $boardurl . '/index.php';

+

+	// These keys shouldn't be set...ever.

+	if (isset($_REQUEST['GLOBALS']) || isset($_COOKIE['GLOBALS']))

+		die('Invalid request variable.');

+

+	// Save some memory.. (since we don't use these anyway.)

+	unset($GLOBALS['HTTP_POST_VARS'], $GLOBALS['HTTP_POST_VARS']);

+	unset($GLOBALS['HTTP_POST_FILES'], $GLOBALS['HTTP_POST_FILES']);

+	unset($GLOBALS['_GET'], $GLOBALS['_POST'], $GLOBALS['_REQUEST'], $GLOBALS['_COOKIE'], $GLOBALS['_FILES']);

+}

+

+function error_handler_cron($error_level, $error_string, $file, $line)

+{

+	global $settings, $modSettings, $db_show_debug;

+

+	// Ignore errors if we're ignoring them or they are strict notices from PHP 5 (which cannot be solved without breaking PHP 4.)

+	if (error_reporting() == 0 || (defined('E_STRICT') && $error_level == E_STRICT && (empty($modSettings['enableErrorLogging']) || $modSettings['enableErrorLogging'] != 2)))

+		return;

+

+	$error_type = 'cron';

+

+	log_error($error_level . ': ' . $error_string, $error_type, $file, $line);

+

+	// If this is an E_ERROR or E_USER_ERROR.... die.  Violently so.

+	if ($error_level % 255 == E_ERROR)

+		die('No direct access...');

+}

+

+function obExit_cron()

+{

+	if (FROM_CLI)

+		die(0);

+	else

+	{

+		header('Content-Type: image/gif');

+		die("\x47\x49\x46\x38\x39\x61\x01\x00\x01\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00\x21\xF9\x04\x01\x00\x00\x00\x00\x2C\x00\x00\x00\x00\x01\x00\x01\x00\x00\x02\x02\x44\x01\x00\x3B");

+	}

+}

+

+// We would like this to be defined, but we don't want to have to load more stuff than necessary.

+// Thus we declare it here, and any legitimate background task must implement this.

+interface SMF_BackgroundTask

+{

+	public function setDetails($details);

+	public function execute();

+}

+?>