<?php
/**
 * Created by PhpStorm.
 * User: inhere
 * Date: 2017年5月21日
 * Time: 上午1:26
 */

namespace Inhere\Queue;

/**
 * Interface QueueInterface
 * @package Inhere\Queue
 *
 * @property string $driver
 */
interface QueueInterface
{
 /**
 * Priorities
 */
 const PRIORITY_HIGH = 0;
 const PRIORITY_NORM = 1;
 const PRIORITY_LOW = 2;

 const PRIORITY_LOW_SUFFIX = '_low';
 const PRIORITY_HIGH_SUFFIX = '_high';

 /**
 * Events list
 */
 const EVENT_BEFORE_PUSH = 'beforePush';
 const EVENT_AFTER_PUSH = 'afterPush';
 const EVENT_ERROR_PUSH = 'errorPush';

 const EVENT_BEFORE_POP = 'beforePop';
 const EVENT_AFTER_POP = 'afterPop';
 const EVENT_ERROR_POP = 'errorPop';

 /**
 * push data
 * @param mixed $data
 * @param int $priority
 * @return bool
 */
 public function push($data, $priority = self::PRIORITY_NORM): bool;

 /**
 * pop data
 * @param null|int $priority If is Null, pop all queue data by priority.
 * @param bool $block Whether block pop
 * @return mixed
 */
 public function pop($priority = null, $block = false);

 /**
 * @param int $priority
 * @return int
 */
 public function count($priority = self::PRIORITY_NORM);

 /**
 * @return string|int
 */
 public function getId();

 /**
 * @return array
 */
 public function getChannels();

 /**
 * @return array
 */
 public function getIntChannels();

 /**
 * @return string
 */
 public function getDriver(): string;

 /**
 * @return int
 */
 public function getErrCode(): int;

 /**
 * @return string
 */
 public function getErrMsg(): string;
}