php 队列类

<?php/**  * PHP Class for queue  * @author [e-mail]  * @copyright DataFrog Beijingbei  Ltd. 2011-07-25  */  class Queue {      public  $length=12;          //默认队列，相当于初始化队列    public  $queue  = array();  //  if String like this "22,23,24"    convert to array to do queue      public  $delimiter=',';      function __construct($queue=array())      {          $this->queue=$queue;    }      /**      * @desc start queue      * @param String  $param  new queue element      */      public function run($param)      {           if(!is_array($this->queue)){              $this->strToQue();//将数组视为队列         }          $currentlength=$this->countqueue();        //Count  the  queue length        echo $currentlength;        echo $this->length.'<br>';           if($currentlength<$this->length&&$this->length>0) {              $this->queAdd($param);          }else if($this->length==0)  //如果为空队列，则将队列初始化为输入的队列        {              $param=empty($param)?0:$param;              $this->queue[]=$param;          }          else {                          for ($i=0;$i<$currentlength-$this->length-1;$i++)//队列比规定的队列多，要删掉队首的元素，才能入队            {                  $this->queRemove();              }              $this->queAdd($param);          }                       return $this->queue;                   }      /**      * String like this "22,23,24"  convert to array to do queue      * @param String $string      * @param String $delimiter      */      public function strToQue (){            if (empty($this->queue))          {              $this->queue=array();          }          else          {              $this->queue=explode($this->delimiter,$this->queue);          }           }      /**      * insert $node into queue      * @param string $node      */      private function queAdd($node){              array_push($this->queue,$node);          $this->countqueue();      }      private function queRemove(){          $node = array_shift($this->queue);          $this->countqueue();          return $node;      }      private function countqueue(){          $currentlength= count($this->queue);          return $currentlength;      }      function __destruct()      {          unset($this->queue);      }  }   //example  $str='88|89|90|56|23|45|69|23|20|100'; $obj=new Queue ($str); $obj->length=8;  // 队列元素长度  $obj->delimiter='|';  //如果队列是字符串，则元素直接的分隔符为| $a=$obj->run('91');   //要添加到队列中的元素 $a=$obj->run('92');  $a=$obj->run('93');  $a=$obj->run('94');  print_r($a);?>