Tasks

<?php
class task
{
    public $handler = '';   //обработчик задачи
    public $query = '';     //задача
    public $params = '';    //дополнительные параметры
    public $priority = 1;   //приоритет
    public $filename='';    //имя файла задачи

    public function __construct($query, $handler = '', $priority = 1, $params = '')
    {
        $this->query = $query;
        $this->priority = intval($priority);
        if (!empty($handler)) $this->handler = $handler;
        if (!empty($params)) $this->params = $params;
        return true;
    }
}

class tasks
{
    ################################################################################
    #### Внимание, здесь требуется настройка - укажите существующую директорию  ####
    ################################################################################
    const tpath = '/home/user/tmpdir/'; //директория для временных файлов

    public static function create($query, $handler = '', $priority = 1, $params = '')
    {
        if (empty($query)) return false;
        $task=new task($query,$handler,$priority,$params);
        if (self::add($task)) return $task;
        else return false;
    }

    public static function add(&$task)
    {
        if (!($task instanceof task)) return false;
        if (empty($task->query)) return false;
        return self::write_task_to_file($task);
    }

    public static function del(&$task)
    {
        if (!empty($task->filename) && file_exists(self::tpath.$task->filename)) return unlink(self::tpath.$task->filename);
        return false;
    }

    public static function update(&$task)
    {
        if (!($task instanceof task)) return false;
        return self::write_task_to_file($task);
    }

    public static function execute(&$task)
    {
        if (!($task instanceof task)) return false;
        if (empty($task->handler)) return false;
        if (!file_exists(self::tpath.$task->filename)) return false;

        if (method_exists('task_handlers',$task->handler))
        {
            $handler=$task->handler;
            $r=task_handlers::$handler($task);
            self::del($task);
            return $r;
        }
        return false;
    }

    public static function get_files_list()
    {
        if (!file_exists(self::tpath)) return false;
        $files = array();
        $dh = opendir(self::tpath);
        while (($f = readdir($dh)) !== false)
        {
            if (is_file(self::tpath.$f) && $f != '..' && $f != '.' && substr($f,-5)=='.task') $files[]=$f;
        }
        return $files;
    }

    public static function get_tasks()
    {
        if (!file_exists(self::tpath)) return false;
        $files=self::get_files_list();
        if (empty($files)) return false;
        $tasks = array();
        foreach ($files as $f)
        {
            $newtask = self::read_task_from_file($f);
            if (!empty($newtask->query)) $tasks[$f] = $newtask;
            unset($newtask);
        }
        return $tasks;
    }

    public static function read_task_from_file($f)
    {
        if (empty($f) || !is_string($f) || !file_exists(self::tpath.$f)) return false;
        $content = @file_get_contents(self::tpath.$f);
        if (empty($content)) return false;
        $d = explode("\n", $content);
        $task=new task(base64_decode($d[0]));
        if (!empty($d[1])) $task->handler = base64_decode($d[1]);
        if (!empty($d[2])) $task->priority = intval($d[2]);
        if (!empty($d[3])) $task->params = unserialize(base64_decode($d[3]));
        $task->filename=$f;
        return $task;
    }

    public static function write_task_to_file(&$task)
    {
        if (!($task instanceof task)) return false;
        if (empty($task->filename)) $task->filename = self::get_new_filename();
        $f=$task->filename;
        $fh=fopen(self::tpath.$f,'wb');
        if (!$fh) return false;
        if (!flock($fh,LOCK_EX)) return false;
        fwrite($fh,base64_encode($task->query)."\n");
        if (!empty($task->handler)) fwrite($fh,base64_encode($task->handler)."\n");
        if (!empty($task->priority)) fwrite($fh,intval($task->priority)."\n");
        if (!empty($task->params)) fwrite($fh,base64_encode(serialize($task->params))."\n");
        flock($fh,LOCK_UN);
        fclose($fh);
        return $f;
    }

    public static function get_new_filename()
    {
        $name=$t=round(microtime(1)*1000);
        $i=0;
        while (file_exists(self::tpath.$name.'.task'))
        {
            $i++;
            $name=$t.'_'.$i;
        }
        return $name.'.task';
    }

}

class task_handlers
{
    #############################################################
    ####### Эти функции-обработчики приведены для примера #######
    #############################################################
    public function mysql(&$task)
    {
        if (class_exists('mysql'))
        {
            if (!mysql::$connected) mysql::connect();
            return mysql::query($task->query);
        }
        else return mysql_query($task->query);
    }

    public function mail(&$task)
    {
        if (function_exists('mailsend')) return mailsend($task->params['to'],$task->params['subject'],$task->params['message'],
                                            $task->params['headers'],$task->params['parameters'],$task->params['immediately']);
        else return mail($task->params['to'],$task->params['subject'],$task->params['message'],$task->params['headers'],$task->params['parameters']);
    }

}
?>