memcache+tp3.2实现消息队列

memcache模型
<?php
namespace Stat\Model;
/*
 * memcache队列类
 * 支持多进程并发写入、读取
 * 边写边读,AB面轮值替换
 * @author lkk/blog.lianq.net
 * @version 0.2
 * @create on 9:25 2012-9-28
 *
 * @edited on 14:03 2013-4-28
 * 修改说明:
 *      1.修改了changeHead方法,当get(1)只取一条数据时$head_key的值没改变的问题
 *      2.修改了clear方法,当队列较小时按最大队列长度删除的问题
 *
 * 使用方法:
 *      $obj = new memcacheQueue('duilie');
 *      $obj->add('1asdf');
 *      $obj->getQueueLength();
 *      $obj->read(11);
 *      $obj->get(8);
 */

class MequeModel{
    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
    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      = 50000;                //(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   [queueName] string  队列名称
     * @param   [expire]    string  过期时间
     * @param   [config]    array   memcache服务器参数
     * @return  NULL
     */
    public function __construct($queueName ='',$expire='',$config =''){
        if(empty($config)){
            self::$client = memcache_pconnect('tcp://m-2ze60467a1719914.memcache.rds.aliyuncs.com',11211);
        }elseif(is_array($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] : 'tcp://m-2ze60467a1719914.memcache.rds.aliyuncs.com';
            $conf['port'] = isset($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)) ? 3600 : (int)$expire+1;
        $this->expire = $expire;
        $this->queueName = $queueName;
        $this->retryNum = 20000;

        $side = memcache_add(self::$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)) $this->sideBHead = ;
if(!isset($this->sideBTail) || empty($this->sideBTail)) $this->sideBTail = ;
}

/*
     * 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, , 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=''){
$result = false;
if(empty($data)) return $result;
if(!$this->getLock()){
return $result;
}
$this->getHeadNTail($this->queueName);
$this->getCurrentSide();

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

if($this->currentTail < self::MAXNUM){
$value_key = $this->queueName .$this->currentSide . self::VALU_KEY . $this->currentTail;
if(memcache_set(self::$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($length=){
if(!is_numeric($length)) return false;
if(empty($length)) $length = self::MAXNUM * ;//默认读取所有
if(!$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, $keys);
if(empty($data)) $data = array();
foreach($keys as $v){//取出之后删除
@memcache_delete(self::$client, $v, );
}
$this->unLock();

return $data;
}

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

//先取上一面的key
$i = $result['lastKey'] = ;
for($i=;$i<$length;$i++){
$result['lastKey'] = $this->lastHead + $i;
if($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 = $result['currentKey'] = ;
for($k=;$k<$j;$k++){
$result['currentKey'] = $this->currentHead + $k;
if($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, ,false, $this->expire);//如果没有,则插入;有则false;
$v = memcache_get(self::$client, $tail_key) +;
memcache_set(self::$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){
$head_key = $this->queueName .$side . self::HEAD_KEY;
$tail_key = $this->queueName .$side . self::TAIL_KEY;
$sideTail = memcache_get(self::$client, $tail_key);
if($headValue < $sideTail){
            memcache_set(self::$client, $head_key,$headValue+,false,$this->expire);
}elseif($headValue >= $sideTail){
$this->resetSide($side);
}
    }

/*
     * 重置队列面,即将该队列面的队首、队尾值置为
     * @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, $head_key,,false,$this->expire);
memcache_set(self::$client, $tail_key,,false,$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 > ){
$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);

$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;
$this->getHeadNTail($this->queueName);
$AHead = $this->sideAHead;$AHead--;
$ATail = $this->sideATail;$ATail++;
$BHead = $this->sideBHead;$BHead--;
$BTail = $this->sideBTail;$BTail++;

//删除A面
for($i=$AHead;$i<$ATail;$i++){
            @memcache_delete(self::$client, $this->queueName.'A'. self::VALU_KEY .$i, );
}

//删除B面
for($j=$BHead;$j<$BTail;$j++){
            @memcache_delete(self::$client, $this->queueName.'A'. self::VALU_KEY .$j, );
}

$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);
}

}