<?php

/**
 * Created by PhpStorm.
 * User: stanley-king
 * Date: 16/1/30
 * Time: 下午3:43
 */
class session
{
    static $stInstance = NULL;
    private $fdestroy = false;
    private $redis = NULL;
    private $enable = false;

    const type = 'redis';
    const save_path = 'tcp://127.0.0.1:6379';
    const prefix = 'PHPREDIS_SESSION';

    static public function instance()
    {
        if(self::$stInstance == NULL) {
            self::$stInstance = new session();
        }
        return self::$stInstance;
    }

    private function __construct()
    {
        $this->redis = new Redis;
        $this->enable = $this->redis->connect('127.0.0.1', 6379);
    }

    public function init()
    {
        @ini_set("session.save_handler", "redis");
        session_save_path(self::save_path);
        session_set_save_handler(
            array(&$this,'onOpen'),
            array(&$this,'onClose'),
            array(&$this,'onRead'),
            array(&$this,'onWrite'),
            array(&$this,'onDestroy'),
            array(&$this,'onGc'),
            array(&$this,'onCreateSid'));
    }

    public function start()
    {
        //会触发，open 和 read 函数
        session_start();
    }

    public function end()
    {
        // 会触发write 和 close 函数
        if($this->fdestroy == false) {
            session_write_close();
        }

        foreach($_SESSION as $key=>$value)
        {
            unset($_SESSION[$key]);
        }
    }

    public function destroy() {
        $this->fdestroy = true;
        session_destroy();//会触发destroy 和 close 函数
    }

    public function onOpen() {
        return true;
    }
    public function onRead($sid)
    {
        $ret = $this->redis->hGet(self::prefix,$sid);
        if(empty($ret)) {
            return '';
        } else {
            fcgi_header("Set-Cookie: PHPSESSID={$sid}");
            return $ret[0];
        }
    }

    public function onClose() {
        return true;
    }

    public function onWrite($sid, $data) {
        return $this->redis->hSet(self::prefix,$sid,$data);
    }

    public function onDestroy($sid) {
        return dcache($sid,self::prefix);
    }

    public function onGc($expire) {
        return true;
    }

//    public function onCreateSid()
//    {
//        $sid = 'vnk730je4l1c20cc479gpoesm6';
//
//        return $sid;
//    }
}