php的memcache類分享

 這篇文章主要介紹了php的memcache類的使用方法(memcache隊列),需要的朋友可以參考下

memcacheQueue.class.php   代碼如下: <?php /**  * PHP memcache 隊列類  * @author LKK/lianq.net  * @version 0.3  * @修改說明:  * 1.放棄了之前的AB面輪值思路,使用類似數組的構造,重寫了此類.  * 2.隊列默認先進先出,但增加了反向讀取功能.  * 3.感謝網友FoxHunter提出的寶貴意見.  * @example:  * $obj = new memcacheQueue('duilie');  * $obj->add('1asdf');  * $obj->getQueueLength();  * $obj->read(10);  * $obj->get(8);  */ class memcacheQueue{  public static $client;   //memcache客戶端連接  public   $access;   //隊列是否可更新  private   $expire;   //過期時間,秒,1~2592000,即30天內  private   $sleepTime;   //等待解鎖時間,微秒  private   $queueName;   //隊列名稱,唯一值  private   $retryNum;   //重試次數,= 10 * 理論並發數  public   $currentHead;  //當前隊首值  public   $currentTail;  //當前隊尾值    const MAXNUM  = 20000;    //最大隊列數,建議上限10K  const HEAD_KEY = '_lkkQueueHead_';  //隊列首kye  const TAIL_KEY = '_lkkQueueTail_';  //隊列尾key  const VALU_KEY = '_lkkQueueValu_';  //隊列值key  const LOCK_KEY = '_lkkQueueLock_';  //隊列鎖key       /**      * 構造函數      * @param string $queueName  隊列名稱      * @param int $expire 過期時間      * @param array $config  memcache配置      *       * @return <type>      */  public function __construct($queueName ='',$expire=0,$config =''){   if(empty($config)){    self::$client = memcache_pconnect('127.0.0.1',11211);   }elseif(is_array($config)){//array('host'=>'127.0.0.1','port'=>'11211')    self::$client = memcache_pconnect($config['host'],$config['port']);   }elseif(is_string($config)){//"127.0.0.1:11211"    $tmp = explode(':',$config);    $conf['host'] = isset($tmp[0]) ? $tmp[0] : '127.0.0.1';    $conf['port'] = isset($tmp[1]) ? $tmp[1] : '11211';    self::$client = memcache_pconnect($conf['host'],$conf['port']);   }   if(!self::$client) return false;     ignore_user_abort(true);//當客戶斷開連接,允許繼續執行   set_time_limit(0);//取消腳本執行延時上限     $this->access = false;   $this->sleepTime = 1000;   $expire = empty($expire) ? 3600 : intval($expire)+1;   $this->expire = $expire;   $this->queueName = $queueName;   $this->retryNum = 1000;     $this->head_key = $this->queueName . self::HEAD_KEY;   $this->tail_key = $this->queueName . self::TAIL_KEY;   $this->lock_key = $this->queueName . self::LOCK_KEY;     $this->_initSetHeadNTail();  }       /**      * 初始化設置隊列首尾值      */  private function _initSetHeadNTail(){   //當前隊列首的數值   $this->currentHead = memcache_get(self::$client, $this->head_key);   if($this->currentHead === false) $this->currentHead =0;     //當前隊列尾的數值   $this->currentTail = memcache_get(self::$client, $this->tail_key);   if($this->currentTail === false) $this->currentTail =0;  }       /**      * 當取出元素時,改變隊列首的數值   * @param int $step 步長值      */  private function _changeHead($step=1){   $this->currentHead += $step;   memcache_set(self::$client, $this->head_key,$this->currentHead,false,$this->expire);  }       /**      * 當添加元素時,改變隊列尾的數值   * @param int $step 步長值      * @param bool $reverse 是否反向      * @return null      */  private function _changeTail($step=1, $reverse =false){   if(!$reverse){    $this->currentTail += $step;   }else{    $this->currentTail -= $step;   }     memcache_set(self::$client, $this->tail_key,$this->currentTail,false,$this->expire);  }       /**      * 隊列是否為空      * @return bool      */  private function _isEmpty(){   return (bool)($this->currentHead === $this->currentTail);  }       /**      * 隊列是否已滿      * @return bool      */  private function _isFull(){   $len = $this->currentTail - $this->currentHead;   return (bool)($len === self::MAXNUM);  }       /**      * 隊列加鎖      */  private function _getLock(){   if($this->access === false){    while(!memcache_add(self::$client, $this->lock_key, 1, false, $this->expire) ){     usleep($this->sleepTime);     @$i++;     if($i > $this->retryNum){//嘗試等待N次      return false;      break;     }    }      $this->_initSetHeadNTail();    return $this->access = true;   }     return $this->access;  }       /**      * 隊列解鎖      */  private function _unLock(){   memcache_delete(self::$client, $this->lock_key, 0);   $this->access = false;  }       /**      * 獲取當前隊列的長度      * 該長度為理論長度,某些元素由於過期失效而丟失,真實長度<=該長度      * @return int      */  public function getQueueLength(){   $this->_initSetHeadNTail();   return intval($this->currentTail - $this->currentHead);  }       /**      * 添加隊列數據      * @param void $data 要添加的數據      * @return bool      */  public function add($data){   if(!$this->_getLock()) return false;     if($this->_isFull()){    $this->_unLock();    return false;   }     $value_key = $this->queueName . self::VALU_KEY . strval($this->currentTail +1);   $result = memcache_set(self::$client, $value_key, $data, MEMCACHE_COMPRESSED, $this->expire);   if($result){    $this->_changeTail();   }     $this->_unLock();   return $result;  }       /**      * 讀取隊列數據      * @param int $length 要讀取的長度(反向讀取使用負數)      * @return array      */  public function read($length=0){   if(!is_numeric($length)) return false;   $this->_initSetHeadNTail();     if($this->_isEmpty()){    return false;   }     if(empty($length)) $length = self::MAXNUM;//默認所有   $keyArr = array();   if($length >0){//正向讀取(從隊列首向隊列尾)    $tmpMin = $this->currentHead;    $tmpMax = $tmpMin + $length;    for($i= $tmpMin; $i<=$tmpMax; $i++){     $keyArr[] = $this->queueName . self::VALU_KEY . $i;    }   }else{//反向讀取(從隊列尾向隊列首)    $tmpMax = $this->currentTail;    $tmpMin = $tmpMax + $length;    for($i= $tmpMax; $i >$tmpMin; $i--){     $keyArr[] = $this->que