好久没有写博客了，今天来一片php使用redis共享session

网上的php将session存放在redis的方法，大多数只是指出了如何存放，并没有涉及到如何存放json格式

我根据网上的资料，整理出自己的代码，使得session能够以json格式存放在redis里面，方便和其他语言的共享

<?php
class RedisSessionHandler implements SessionHandlerInterface{
	private $redis;
	private $config;
	private $namespace;
	private $session_id = null;
	private $maxlifetime = null;


	public function __construct($config) {
		//初始化redis
		$this->config = array(
				"namespace"=>"",
				"host"=>"127.0.0.1",
				"port"=>"6789",
				"auth"=>"",
				"db"=>0
				);
		$this->config = array_merge($this->config,$config);
		$this->redis = new Redis();
		$this->redis->connect($this->config["host"],$this->config["port"]);
		if(!empty($this->config["auth"]))
		{
			$ret = $this->redis->auth($this->config["auth"]);
			if(!$ret)
			{
				return false;
			}
			$this->redis->select($this->config["db"]);
		}
		//设置当前的sessionid生成的命名空间
		$this->namespace = $this->config["namespace"];
		if(!empty($this->namespace))
		{
			$this->namespace .=":";
		}
		//设置初始化的session_id
		if(empty($session_name))
		{
			$session_name = ini_get("session.name");
		}
		//没有设置过session，新的会话，需要重新生成sessionid
		if ( empty($_COOKIE[$session_name]) ) {
			$this->session_id = true;
		}
	}
	public function open($savePath, $sessionName){
		$connect = $this->redis->connect($this->config["host"],$this->config["port"]);
		if(!$connect) return false;
		if(!empty($this->config["auth"]))
		{
			$ret = $this->redis->auth($this->config["auth"]);
			if(!$ret)
			{
				return false;
			}
			$this->redis->select($this->config["db"]);
		}
		//在初次设置的时候，重设PHP本身的session_id并判断session_id是否已经存在
		$id = session_id();
		if($this->session_id && $this->session_id != $id){
			do{
				$this->session_id = $this->session_id();
			}while($this->redis->exists($this->namespace.$this->session_id));
			session_id($this->session_id);
		}
		//设置生成周期
		$this->maxlifetime = ini_get("session.gc_maxlifetime");
		return true;
	}
	public function close(){
		$this->redis->close();
		return true;
	}
	public function read($id){
		$data = json_decode($this->redis->get($this->namespace.$id),TRUE);
		return serialize($data);
	}
	public function write($id, $data){
		$json = json_encode(unserialize($data),JSON_UNESCAPED_UNICODE|JSON_NUMERIC_CHECK);
		return $this->redis->setex($this->namespace.$id,$this->maxlifetime,$json);
	}
	public function destroy($id){
		$this->redis->delete($this->namespace.$id);
		return true;
	}
	public function gc($maxlifetime){
		return true;
	}
	/**
	 * 生成guid
	 */
	private function session_id(){
		$uid = uniqid("", true);
		$data = $this->namespace;
		$data .= $_SERVER["REQUEST_TIME"];
		$data .= $_SERVER["HTTP_USER_AGENT"];
		$data .= $_SERVER["SERVER_ADDR"];
		$data .= $_SERVER["SERVER_PORT"];
		$data .= $_SERVER["REMOTE_ADDR"];
		$data .= $_SERVER["REMOTE_PORT"];
		$hash = strtoupper(hash("ripemd128", $uid . md5($data)));
		return substr($hash,0,32);
	}
}


$handler = new RedisSessionHandler($param);
session_set_save_handler($handler, true);
session_start();
/*
   if(empty($_SESSION)){
   $_SESSION["test"]= ["a"=>1,"b"=>2];
   }
   var_dump($_SESSION);
 */

需要把session.serialize_handler 设置为php_serialize

原理:自己写代码实现SessionHandlerInterface 接口，在写入和读出时进行格式转换，使得session能够以json格式存放在redis里面。