欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  php教程

php自己实现memcached的队列类

程序员文章站 2022-04-25 19:13:11
...
add('1asdf');
 *      $obj->getQueueLength();
 *      $obj->read(11);
 *      $obj->get(8);
 */

class memcacheQueue{
    public static   $client;            //memcache客户端连接
    public          $access;            //队列是否可更新   
    private         $currentSide;       //当前轮值的队列面:A/B
    private         $lastSide;          //上一轮值的队列面:A/B
    private         $sideAHead;         //A面队首值
    private         $sideATail;         //A面队尾值
    private         $sideBHead;         //B面队首值
    private         $sideBTail;         //B面队尾值
    private         $currentHead;       //当前队首值
    private         $currentTail;       //当前队尾值
    private         $lastHead;          //上轮队首值
    private         $lastTail;          //上轮队尾值 
    private         $expire;            //过期时间,秒,1~2592000,即30天内;0为永不过期
    private         $sleepTime;         //等待解锁时间,微秒
    private         $queueName;         //队列名称,唯一值
    private         $retryNum;          //重试次数,= 10 * 理论并发数

    const   MAXNUM      = 2000;                 //(单面)最大队列数,建议上限10K
    const   HEAD_KEY    = '_lkkQueueHead_';     //队列首kye
    const   TAIL_KEY    = '_lkkQueueTail_';     //队列尾key
    const   VALU_KEY    = '_lkkQueueValu_';     //队列值key
    const   LOCK_KEY    = '_lkkQueueLock_';     //队列锁key
    const   SIDE_KEY    = '_lkkQueueSide_';     //轮值面key

    /*
     * 构造函数
     * @param   [config]    array   memcache服务器参数
     * @param   [queueName] string  队列名称
     * @param   [expire]    string  过期时间
     * @return  NULL
     */
    public function __construct($queueName ='',$expire='',$config =''){
        if(empty($config)){
            self::$client = memcache_pconnect('localhost',11211);
        }elseif(is_array($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);//当客户断开连接,允许继续执行
        set_time_limit(0);//取消脚本执行延时上限

        $this->access = false;
        $this->sleepTime = 1000;
        $expire = (empty($expire) && $expire!=0) ? 3600 : (int)$expire;
        $this->expire = $expire;
        $this->queueName = $queueName;
        $this->retryNum = 10000;

        $side = memcache_add(self::$client, $queueName . self::SIDE_KEY, 'A',false, $expire);
        $this->getHeadNTail($queueName);
        if(!isset($this->sideAHead)  empty($this->sideAHead)) $this->sideAHead = 0;
        if(!isset($this->sideATail)  empty($this->sideATail)) $this->sideATail = 0;
        if(!isset($this->sideBHead)  empty($this->sideBHead)) $this->sideBHead = 0;
        if(!isset($this->sideBHead)  empty($this->sideBHead)) $this->sideBHead = 0;
    }

    /*
     * 获取队列首尾值
     * @param   [queueName] string  队列名称
     * @return  NULL
     */
    private function getHeadNTail($queueName){
        $this->sideAHead = (int)memcache_get(self::$client, $queueName.'A'. self::HEAD_KEY);
        $this->sideATail = (int)memcache_get(self::$client, $queueName.'A'. self::TAIL_KEY);
        $this->sideBHead = (int)memcache_get(self::$client, $queueName.'B'. self::HEAD_KEY);
        $this->sideBTail = (int)memcache_get(self::$client, $queueName.'B'. self::TAIL_KEY);
    }

    /*
     * 获取当前轮值的队列面
     * @return  string  队列面名称
     */
    public function getCurrentSide(){
        $currentSide = memcache_get(self::$client, $this->queueName . self::SIDE_KEY);
        if($currentSide == 'A'){
            $this->currentSide = 'A';
            $this->lastSide = 'B';  

            $this->currentHead  = $this->sideAHead;
            $this->currentTail  = $this->sideATail;
            $this->lastHead     = $this->sideBHead;
            $this->lastTail     = $this->sideBTail;         
        }else{
            $this->currentSide = 'B';
            $this->lastSide = 'A';

            $this->currentHead  = $this->sideBHead;
            $this->currentTail  = $this->sideBTail;
            $this->lastHead     = $this->sideAHead;
            $this->lastTail     = $this->sideATail;                     
        }

        return $this->currentSide;
    }

    /*
     * 队列加锁
     * @return boolean
     */
    private function getLock(){
        if($this->access === false){
            while(!memcache_add(self::$client, $this->queueName .self::LOCK_KEY, 1, false, $this->expire) ){
                usleep($this->sleepTime);
                @$i++;
                if($i > $this->retryNum){//尝试等待N次
                    return false;
                    break;
                }
            }
            return $this->access = true;
        }
        return false;
    }

    /*
     * 队列解锁
     * @return NULL
     */
    private function unLock(){
        memcache_delete(self::$client, $this->queueName .self::LOCK_KEY);
        $this->access = false;
    }

    /*
     * 添加数据
     * @param   [data]  要存储的值
     * @return  boolean
     */
    public function add($data){
        $result = false;
        if(!$this->getLock()){
            return $result;
        } 
        $this->getHeadNTail($this->queueName);
        $this->getCurrentSide();

        if($this->isFull()){
            $this->unLock();
            return false;
        }

        if($this->currentTail queueName .$this->currentSide . self::VALU_KEY . $this->currentTail;
            if(memcache_add(self::$client, $value_key, $data, false, $this->expire)){
                $this->changeTail();
                $result = true;
            }
        }else{//当前队列已满,更换轮值面
            $this->unLock();
            $this->changeCurrentSide();
            return $this->add($data);
        }

        $this->unLock();
        return $result;
    }

    /*
     * 取出数据
     * @param   [length]    int 数据的长度
     * @return  array
     */
    public function get($length=0){
        if(!is_numeric($length)) return false;
        if(empty($length)) $length = self::MAXNUM * 2;//默认读取所有
        if(!$this->getLock()) return false;

        if($this->isEmpty()){
            $this->unLock();
            return false;
        }

        $keyArray   = $this->getKeyArray($length);
        $lastKey    = $keyArray['lastKey'];
        $currentKey = $keyArray['currentKey'];
        $keys       = $keyArray['keys'];
        $this->changeHead($this->lastSide,$lastKey);
        $this->changeHead($this->currentSide,$currentKey);

        $data   = @memcache_get(self::$client, $keys);
        foreach($keys as $v){//取出之后删除
            @memcache_delete(self::$client, $v, 0);
        }
        $this->unLock();

        return $data;
    }

    /*
     * 读取数据
     * @param   [length]    int 数据的长度
     * @return  array
     */
    public function read($length=0){
        if(!is_numeric($length)) return false;
        if(empty($length)) $length = self::MAXNUM * 2;//默认读取所有
        $keyArray   = $this->getKeyArray($length);
        $data   = @memcache_get(self::$client, $keyArray['keys']);
        return $data;
    }

    /*
     * 获取队列某段长度的key数组
     * @param   [length]    int 队列长度
     * @return  array
     */
    private function getKeyArray($length){
        $result = array('keys'=>array(),'lastKey'=>array(),'currentKey'=>array());
        $this->getHeadNTail($this->queueName);
        $this->getCurrentSide();
        if(empty($length)) return $result;

        //先取上一面的key
        $i = $result['lastKey'] = 0;
        for($i=0;$ilastHead + $i;
            if($result['lastKey'] >= $this->lastTail) break;
            $result['keys'][] = $this->queueName .$this->lastSide . self::VALU_KEY . $result['lastKey'];
        }

        //再取当前面的key
        $j = $length - $i;
        $k = $result['currentKey'] = 0;
        for($k=0;$kcurrentHead + $k;
            if($result['currentKey'] >= $this->currentTail) break;
            $result['keys'][] = $this->queueName .$this->currentSide . self::VALU_KEY . $result['currentKey'];
        }

        return $result;
    }

    /*
     * 更新当前轮值面队列尾的值
     * @return  NULL
     */
    private function changeTail(){
        $tail_key = $this->queueName .$this->currentSide . self::TAIL_KEY;
        memcache_add(self::$client, $tail_key, 0,false, $this->expire);//如果没有,则插入;有则false;
        //memcache_increment(self::$client, $tail_key, 1);//队列尾+1
        $v = memcache_get(self::$client, $tail_key) +1;
        memcache_set(self::$client, $tail_key,$v,false,$this->expire);
    }

    /*
     * 更新队列首的值
     * @param   [side]      string  要更新的面
     * @param   [headValue] int     队列首的值
     * @return  NULL
     */
    private function changeHead($side,$headValue){
        if($headValue queueName .$side . self::HEAD_KEY;
        $tail_key = $this->queueName .$side . self::TAIL_KEY;
        $sideTail = memcache_get(self::$client, $tail_key);
        if($headValue expire);
        }elseif($headValue >= $sideTail){
            $this->resetSide($side);
        }
    }

    /*
     * 重置队列面,即将该队列面的队首、队尾值置为0
     * @param   [side]  string  要重置的面
     * @return  NULL
     */
    private function resetSide($side){
        $head_key = $this->queueName .$side . self::HEAD_KEY;
        $tail_key = $this->queueName .$side . self::TAIL_KEY;
        memcache_set(self::$client, $head_key,0,false,$this->expire);
        memcache_set(self::$client, $tail_key,0,false,$this->expire);
    }

    /*
     * 改变当前轮值队列面
     * @return  string
     */
    private function changeCurrentSide(){
        $currentSide = memcache_get(self::$client, $this->queueName . self::SIDE_KEY);
        if($currentSide == 'A'){
            memcache_set(self::$client, $this->queueName . self::SIDE_KEY,'B',false,$this->expire);
            $this->currentSide = 'B';
        }else{
            memcache_set(self::$client, $this->queueName . self::SIDE_KEY,'A',false,$this->expire);
            $this->currentSide = 'A';
        }
        return $this->currentSide;
    }

    /*
     * 检查当前队列是否已满
     * @return  boolean
     */
    public function isFull(){
        $result = false;
        if($this->sideATail == self::MAXNUM && $this->sideBTail == self::MAXNUM){
            $result = true;
        }
        return $result;
    }

    /*
     * 检查当前队列是否为空
     * @return  boolean
     */
    public function isEmpty(){
        $result = true;
        if($this->sideATail > 0  $this->sideBTail > 0){
            $result = false;
        }
        return $result;
    }

    /*
     * 获取当前队列的长度
     * 该长度为理论长度,某些元素由于过期失效而丢失,真实长度小于或等于该长度
     * @return  int
     */
    public function getQueueLength(){
        $this->getHeadNTail($this->queueName);
        $this->getCurrentSide();

        $sideALength = $this->sideATail - $this->sideAHead;
        $sideBLength = $this->sideBTail - $this->sideBHead;
        $result = $sideALength + $sideBLength;

        return $result;
    }

    /*
     * 清空当前队列数据,仅保留HEAD_KEY、TAIL_KEY、SIDE_KEY三个key
     * @return  boolean
     */
    public function clear(){
        if(!$this->getLock()) return false;
        for($i=0;$i<:maxnum this-="">queueName.'A'. self::VALU_KEY .$i, 0);
            @memcache_delete(self::$client, $this->queueName.'B'. self::VALU_KEY .$i, 0);
        }
        $this->unLock();
        $this->resetSide('A');
        $this->resetSide('B');
        return true;
    }

    /*
     * 清除所有memcache缓存数据
     * @return  NULL
     */
    public function memFlush(){
        memcache_flush(self::$client);
    }

}
;$i++){>