php自己實現memcached的隊列類
add('1asdf');
* $obj->getQueueLength();
* $obj->read(11);
* $obj->get(8);
*/
class memcacheQueue{
public static $client; //memcache客戶端連接
public $access; //隊列是否可更新
private $currentSide; //當前輪值的隊列面:A/B
private $lastSide; //上一輪值的隊列面:A/B
private $sideAHead; //A面隊首值
private $sideATail; //A面隊尾值
private $sideBHead; //B面隊首值
private $sideBTail; //B面隊尾值
private $currentHead; //當前隊首值
private $currentTail; //當前隊尾值
private $lastHead; //上輪隊首值
private $lastTail; //上輪隊尾值
private $expire; //過期時間,秒,1~2592000,即30天內;0為永不過期
private $sleepTime; //等待解鎖時間,微秒
private $queueName; //隊列名稱,唯一值
private $retryNum; //重試次數,= 10 * 理論並發數
const MAXNUM = 2000; //(單面)最大隊列數,建議上限10K
const HEAD_KEY = '_lkkQueueHead_'; //隊列首kye
const TAIL_KEY = '_lkkQueueTail_'; //隊列尾key
const VALU_KEY = '_lkkQueueValu_'; //隊列值key
const LOCK_KEY = '_lkkQueueLock_'; //隊列鎖key
const SIDE_KEY = '_lkkQueueSide_'; //輪值面key
/*
* 構造函數
* @param [config] array memcache服務器參數
* @param [queueName] string 隊列名稱
* @param [expire] string 過期時間
* @return NULL
*/
public function __construct($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);//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) && $expire!=0) ? 3600 : (int)$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)) $this->sideBHead = 0;
}
/*
* 獲取隊列首尾值
* @param [queueName] string 隊列名稱
* @return NULL
*/
private function getHeadNTail($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);
}
/*
* 獲取當前輪值的隊列面
* @return string 隊列面名稱
*/
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 $this->currentSide;
}
/*
* 隊列加鎖
* @return boolean
*/
private function getLock(){
if($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){//嘗試等待N次
return false;
break;
}
}
return $this->access = true;
}
return false;
}
/*
* 隊列解鎖
* @return NULL
*/
private function unLock(){
memcache_delete(self::$client, $this->queueName .self::LOCK_KEY);
$this->access = false;
}
/*
* 添加數據
* @param [data] 要存儲的值
* @return boolean
*/
public function add($data){
$result = false;
if(!$this->getLock()){
return $result;
}
$this->getHeadNTail($this->queueName);
$this->getCurrentSide();
if($this->isFull()){
$this->unLock();
return false;
}
if($this->currentTail < self::MAXNUM){
$value_key = $this->queueName .$this->currentSide . self::VALU_KEY . $this->currentTail;
if(memcache_add(self::$client, $value_key, $data, false, $this->expire)){
$this->changeTail();
$result = true;
}
}else{//當前隊列已滿,更換輪值面
$this->unLock();
$this->changeCurrentSide();
return $this->add($data);
}
$this->unLock();
return $result;
}
/*
* 取出數據
* @param [length] int 數據的長度
* @return array
*/
public function get($length=0){
if(!is_numeric($length)) return false;
if(empty($length)) $length = self::MAXNUM * 2;//默認讀取所有
if(!$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 $v){//取出之後刪除
@memcache_delete(self::$client, $v, 0);
}
$this->unLock();
return $data;
}
/*
* 讀取數據
* @param [length] int 數據的長度
* @return array
*/
public function read($length=0){
if(!is_numeric($length)) return false;
if(empty($length)) $length = self::MAXNUM * 2;//默認讀取所有
$keyArray = $this->getKeyArray($length);
$data = @memcache_get(self::$client, $keyArray['keys']);
return $data;
}
/*
* 獲取隊列某段長度的key數組
* @param [length] int 隊列長度
* @return array
*/
private function getKeyArray($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;$i<$length;$i++){
$result['lastKey'] = $this->lastHead + $i;
if($result['lastKey'] >= $this->lastTail) break;
$result['keys'][] = $this->queueName .$this->lastSide . self::VALU_KEY . $result['lastKey'];
}
//再取當前面的key
$j = $length - $i;
$k = $result['currentKey'] = 0;
for($k=0;$k<$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;
}
/*
* 更新當前輪值面隊列尾的值
* @return NULL
*/
private function changeTail(){
$tail_key = $this->queueName .$this->currentSide . self::TAIL_KEY;
memcache_add(self::$client, $tail_key, 0,false, $this->expire);//如果沒有,則插入;有則false;
//memcache_increment(self::$client, $tail_key, 1);//隊列尾+1
$v = memcache_get(self::$client, $tail_key) +1;
memcache_set(self::$client, $tail_key,$v,false,$this->expire);
}
/*
* 更新隊列首的值
* @param [side] string 要更新的面
* @param [headValue] int 隊列首的值
* @return NULL
*/
private function changeHead($side,$headValue){
if($headValue < 1) return false;
$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+1,false,$this->expire);
}elseif($headValue >= $sideTail){
$this->resetSide($side);
}
}
/*
* 重置隊列面,即將該隊列面的隊首、隊尾值置為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);
}
/*
* 改變當前輪值隊列面
* @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;
}
/*
* 檢查當前隊列是否已滿
* @return boolean
*/
public function isFull(){
$result = false;
if($this->sideATail == self::MAXNUM && $this->sideBTail == self::MAXNUM){
$result = true;
}
return $result;
}
/*
* 檢查當前隊列是否為空
* @return boolean
*/
public function isEmpty(){
$result = true;
if($this->sideATail > 0 || $this->sideBTail > 0){
$result = false;
}
return $result;
}
/*
* 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，真實長度小於或等於該長度
* @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 $result;
}
/*
* 清空當前隊列數據,僅保留HEAD_KEY、TAIL_KEY、SIDE_KEY三個key
* @return boolean
*/
public function clear(){
if(!$this->getLock()) return false;
for($i=0;$iqueueName.'A'. self::VALU_KEY .$i, 0);
@memcache_delete(self::$client, $this->queueName.'B'. self::VALU_KEY .$i, 0);
}
$this->unLock();
$this->resetSide('A');
$this->resetSide('B');
return true;
}
/*
* 清除所有memcache緩存數據
* @return NULL
*/
public function memFlush(){
memcache_flush(self::$client);
}
}
