File Source for cron

<?php
/**
* Execute cron jobs.
*
* Example to use CLI:
* >c:\php4\php cron_exec.php
* >c:\php4\php-cli cron_exec.php
*
* @package pond
*/
/**
* Include config
*/
require_once dirname(__FILE__).'/../qp_config/_config.php';
$no_session = true;
require_once $inc_path .'_main.inc.php';
/**
* Cron support functions
*/
load_funcs( '/cron/_cron.funcs.php' );
/**
* @global integer Quietness.
* 1 suppresses trivial/informative messages,
* 2 suppresses success messages,
* 3 suppresses errors.
*/
$quiet = 0;
if( $is_cli )
{ // called through Command Line Interface, handle args:
if( isset( $_SERVER['argc'], $_SERVER['argv'] ) )
{
$argc = $_SERVER['argc'];
$argv = $_SERVER['argv'];
}
if( isset($argv) )
{ // may not be set for CGI
foreach( array_slice($argv, 1) as $v )
{
switch( $v )
{
case '-h':
case '--help':
// display help:
echo $argv[0], ' - Execute cron jobs for ', $app_name, "\n";
echo "\n";
echo "Options:\n";
echo " -q --quiet: Be quiet (do not output a message, if there are no jobs).\n";
echo " This is especially useful, when running as a cron job.\n";
echo " You can use this up to three times to increase quietness.\n";
echo " Successful runs can be made silent with \"-q -q\".\n";
exit(0);
break;
case '-q':
case '--quiet':
// increase quietness:
$quiet++;
break;
default:
echo 'Invalid option "'.$v.'". Use "-h" or "--help" for a list of options.'."\n";
die(1);
}
}
}
}
else
{ // This is a web request:
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>Cron exec</title>
<link rel="stylesheet" type="text/css" href="<?php echo $rsc_url ?>css/basic.css">
</head>
<body>
<h1>Cron exec</h1>
<p>This script will execute the next task in the cron queue.
You should normally call it with the CLI (command line interface) version of PHP
and automate that call through a cron.</p>
<?php
}
/*
* The following will feel a little bloated...
* BUT it is actually a pretty nifty design to prevent double execution of tasks without any transaction!
* The trick is to rely on the primary key of the cron__log table.
*/
// Get next task to run in queue which has not started execution yet:
$sql = 'SELECT *
FROM T_cron__task LEFT JOIN T_cron__log ON ctsk_ID = clog_ctsk_ID
WHERE clog_ctsk_ID IS NULL
AND ctsk_start_datetime <= '.$DB->quote( date2mysql($localtimenow) ).'
ORDER BY ctsk_start_datetime ASC, ctsk_ID ASC
LIMIT 1';
$task = $DB->get_row( $sql, OBJECT, 0, 'Get next task to run in queue which has not started execution yet' );
if( empty( $task ) )
{
cron_log( 'There is no task to execute yet.', 0 );
}
else
{
$ctsk_ID = $task->ctsk_ID;
$ctsk_name = $task->ctsk_name;
cron_log( 'Requesting lock on task #'.$ctsk_ID.' ['.$ctsk_name.']', 0 );
$DB->halt_on_error = false;
$DB->show_errors = false;
$sql = 'INSERT INTO T_cron__log( clog_ctsk_ID, clog_realstart_datetime, clog_status)
VALUES( '.$ctsk_ID.', '.$DB->quote( date2mysql($localtimenow) ).', "started" )';
// Duplicate query for tests!
// $DB->query( $sql, 'Request lock' );
if( $DB->query( $sql, 'Request lock' ) != 1 )
{ // This has no affected exactly ONE row: error! (probably locked -- duplicate key -- by a concurrent process)
$DB->show_errors = true;
$DB->halt_on_error = true;
cron_log( 'Could not lock. Task is probably handled by another process.', 2 );
}
else
{
if( !empty( $task->ctsk_repeat_after ) )
{ // This task wants to be repeated:
// Note: we use the current time for 2 reasons: 1) prevent scheduling something in the past AND 2) introduce variety so that everyone doesn't run his repeated tasks at the same exact time, especially pings, pollings...
$new_start_datetime = $localtimenow + $task->ctsk_repeat_after;
$sql = 'INSERT INTO T_cron__task( ctsk_start_datetime, ctsk_repeat_after, ctsk_name, ctsk_controller, ctsk_params )
VALUES( '.$DB->quote(date2mysql($new_start_datetime)).', '.$DB->quote($task->ctsk_repeat_after).', '
.$DB->quote($ctsk_name).', '.$DB->quote($task->ctsk_controller).', '.$DB->quote($task->ctsk_params).' )';
$DB->query( $sql, 'Schedule repeated task.' );
}
$DB->show_errors = true;
$DB->halt_on_error = true;
cron_log( 'Starting task #'.$ctsk_ID.' ['.$ctsk_name.'] at '.date( 'H:i:s', $localtimenow ).'.', 1 );
if( empty($task->ctsk_params) )
{
$cron_params = array();
}
else
{
$cron_params = unserialize( $task->ctsk_params );
}
// The job may need to know its ID (to set logical locks for example):
$cron_params['ctsk_ID'] = $ctsk_ID;
// EXECUTE
call_job( $task->ctsk_controller, $cron_params );
// Record task as finished:
if( empty($timestop) )
{
$timestop = time() + $time_difference;
}
$sql = ' UPDATE T_cron__log
SET clog_status = '.$DB->quote($result_status).',
clog_realstop_datetime = '.$DB->quote( date2mysql($timestop) ).',
clog_messages = '.$DB->quote($result_message) /* May be NULL */.'
WHERE clog_ctsk_ID = '.$ctsk_ID;
$DB->query( $sql, 'Record task as finished.' );
}
}
// Detect timed out tasks:
$sql = ' UPDATE T_cron__log
SET clog_status = "timeout"
WHERE clog_status = "started"
AND clog_realstart_datetime < '.$DB->quote( date2mysql( time() + $time_difference - $cron_timeout_delay ) );
$DB->query( $sql, 'Detect cron timeouts.' );
if( ! $is_cli )
{ // This is a web request:
echo '<p><a href="cron_exec.php">Refresh Now!</a></p>';
echo '<p>This page should refresh automatically in 15 seconds...</p>';
echo '';
echo '<meta http-equiv="Refresh" content="15" />';
?>
</body>
</html>
<?php
}
?>

Source for file cron_exec.php