redis单例模式写法

<?php /**只看红色重点 * =========================================================== * ZW_Memory_Cache * Description * ZW_Memory_Cache * @Author [e-mail] * @Version 1.0 * @Copyright Zhuweiwei * Copyright © 2008-2012 * China. All Rights Reserved. * =========================================================== */ namespace ZW\Memory; use \Redis as Redis; use ZW\Conf\Memory as Conf; class Handle { private $handle = NULL; private static $_instance = NULL; //定义私有的属性变量 public static function getInstance() { //定义公用的静态方法 if (NULL == self::$_instance) { self::$_instance = new self; } return self::$_instance; } public function __construct() { $redis = new Redis();  //实例化redis $redis->connect(Conf::HOST, Conf::PORT); $redis->auth(Conf::AUTH); $this->handle = &$redis; //将变量与redis通过引用符关联在一起，以后直接使用handle即可，相当于将redis付给一个变量，这是另一种写法 $this->handle->select(ENVIRONMENT); } public function __destruct() { $this->handle->close(); } public function get($k) { return $this->handle->get($k . ''); //获取redis键名 } public function set($k, $v) { return $this->handle->set($k . '', $v . ''); } public function setex($k, $v, $ttl = SEC_HOUR) { return $this->handle->setex($k, intval($ttl), $v); } public function del($k) { return $this->handle->delete($k); } public function increment($k, $step = 1, $def = 0) { if (!$this->handle->exists($k)) { $this->handle->set($k, intval($def)); } return $this->handle->incrBy($k, max(1, $step)); } public function decrement($k, $step = 1, $def = 0) { if (!$this->handle->exists($k)) { $this->handle->set($k, intval($def)); } return $this->handle->decrBy($k, max(1, $step)); } public function arrGet(array $arrKey) { return $this->handle->mGet($arrKey); } public function arrSet(array $arrKv) { return $this->handle->mset($arrKv); } public function getListAt($k, $index) { return $this->handle->lGet($k, $index); } public function setListAt($k, $index, $v) { return $this->handle->lSet($k, $index, $v); } public function pushListHead($k, $v) { return $this->handle->lPush($k, $v); } public function pushListTail($k, $v) { return $this->handle->rPush($k, $v); } public function popListHead($k) { return $this->handle->lPop($k); } public function popListTail($k) { return $this->handle->rPop($k); } public function getListSize($k) { return $this->handle->lSize($k); } public function ttl($k) { return $this->handle->ttl($k); } public function setnx($k, $v){ return $this->handle->setnx($k, $v); } public function exists($k) { return $this->handle->exists($k); } public function expire($k, $ttl) { $this->handle->expire($k, intval($ttl)); } public function persist($k) { $this->handle->persist($k); } public function expireAt($k, $timeStamp) { $this->handle->expireAt($k, $timeStamp); } public function append($k, $append) { $this->handle->append($k, $append); } public function keys($regexKey) { return $this->handle->keys($regexKey); } }