封装php redis缓存操作类

封装php redis缓存操作类，集成了连接redis并判断连接是否成功，redis数据库选择，检测redis键是否存在，获取值，写入值，设置生存时间和删除清空操作。

        php redis类代码：

<?php
/**
* ?redisdrive.class.php
* php redis 操作类
**/
class redisdrive{
???//键名
???public $key;
???//值
???public $value;
???//默认生存时间
???public $expire = 86400; /*60*60*24*/
???//连接是否成功
???public $redis;
???//连接redis服务器ip
???public $ip = ‘127.0.0.1‘;
???//端口
???public $port = 6379;
???//密码
???private $password = null;
???//数据库
???public $dbindex = 0;

???/**
????* 自动连接到redis缓存
????*/
???public function __construct(){
???????//判断php是否支持redis扩展
???????if(extension_loaded(‘redis‘)){
???????????//实例化redis
???????????if($this->redis = new redis()){
???????????????//ping连接
???????????????if(!$this->ping()){
???????????????????$this->redis = false;
???????????????}else{
???????????????????????//连接通后的数据库选择和密码验证操作
???????????????????$this->redis -> select($this->dbindex);
???????????????????$this->redis->auth($this->password);
???????????????}
???????????}else{
???????????????$this->redis = false;
???????????}
???????}else{
???????????$this->redis = false;
???????}
???}

???/**
????* ping redis 的连通性
????*/
???public function ping(){
???????if($this->redis->connect($this->ip,$this->port)){
???????????return true;
???????}else{
??????????return false;
???????}
???}

???/**
????* 检测redis键是否存在
????*/
???public function exists(){
???????if($this->redis->exists($this->key)){
???????????return true;
???????}else{
???????????return false;
???????}
???}

???/**
????* 获取redis键的值
????*/
???public function get(){
???????if($this->exists()){
???????????return json_decode($this->redis->get($this->key),true);
???????}else{
???????????return false;
???????}
???}

???/**
????* 带生存时间写入key
????*/
???public function setex(){
???????return $this->redis->setex($this->key,$this->expire,json_encode($this->value));
???}

???/**
????* 设置redis键值
????*/
???public function set(){
???????if($this->redis->set($this->key,json_encode($this->value))){
???????????return $this->redis->expire($this->key,$this->expire);
???????}else{
???????????return false;
???????}
???}

???/**
????* 获取key生存时间
????*/
???public function ttl(){
???????return $this->redis->ttl($this->key);
???}

???/**
????*删除key
????*/
???public function del(){
???????return $this->redis->del($this->key);
???}

???/**
????* 清空所有数据
????*/
???public function flushall(){
???????return $this->redis->flushall();
???}

???/**
????* 获取所有key
????*/
???public function keys(){
???????return $this->redis->keys(‘*‘);
???}

}
???????

???????实例化调用：

???????判断redis是否可用和当设置了redis session 时redis不可用转回session文件操作。当redis可用时获取指定的键值如果存在就从redis中获取数据，如果不能存在就重新从数据库获取数据再写入redis，redis不可用时直接从数据库获取操作。

//实例化
$redis = new redisdrive();
$redis = false;
//是否可用判断
if($redis->redis==false){
???$redis = false;
???//如果把session存入了redis则在redis不可用时把session切换回文件存储
???ini_set(‘session.save_handler‘,‘files‘);
???ini_set(‘session.save_path‘,‘/tmp‘);
}else{
???$redis = true;
}

//redis判断和数据读取缓存操作设置
if($redis){
???//设置redis键
???$redis->key = ‘res‘;
???//获取redis键的值
???$res_mysql = $redis->get();
???//如果没获取到redis键的值得数据则从数据库获取并写入缓存
???if(!$res){
???????//设置生存时间
???????$redis->expire = 60*60*6;
???????//设置键
???????$redis->key = ‘res‘;

???????//数据库获取数据$res
???????
???????//获取到数据$res，赋值
???????$redis->value = $res;
???????//写入到redis中
???????$redis->set(); ???
???}
}else{
???//数据库获取数据
}