用PHP寫Yaf：Yaf_Registry類

代碼

<?php

/**
 * Created by PhpStorm.
 * User: zhangyoulun
 * Date: 2017/7/13
 * Time: 20:02
 */
class Yaf_Registry
{
    protected static $_instance = null;
    protected $_entries = null;

    private function __construct(){}
    private function __clone(){}

    /**
     * 根據name獲取value，如果爲空則返回null
     *
     * @param $name
     * @return mixed|null
     */
    public static function get($name)
    {
        if(key_exists($name, self::getInstance()->_entries)){
            return self::getInstance()->_entries[$name];
        }
        return null;
    }

    /**
     * 查看是否存在鍵爲name的值
     *
     * @param $name
     * @return bool
     */
    public static function has($name)
    {
        return key_exists($name, self::getInstance()->_entries);
    }

    /**
     * 設置$name=>$value
     *
     * @param $name
     * @param $value
     * @return true
     */
    public static function set($name, $value)
    {
        self::getInstance()->_entries[$name] = $value;
        return true;
    }

    /**
     * 刪除鍵爲$name的值
     *
     * @param $name
     * @return true
     */
    public static function del($name)
    {
        unset(self::getInstance()->_entries[$name]);
        return true;
    }

    private static function getInstance()
    {
        if(!self::$_instance instanceof self){
            self::$_instance = new self();

            self::$_instance->_entries = [];
        }

        return self::$_instance;
    }
}

測試

<?php
require '../src/Yaf_Registry.php';

Yaf_Registry::set('aaa', 111);
Yaf_Registry::set('bbb', (object)[]);

var_dump(Yaf_Registry::get('aaa'));
var_dump(Yaf_Registry::has('aaa'));
var_dump(Yaf_Registry::del('aaa'));
var_dump(Yaf_Registry::has('aaa'));
var_dump(Yaf_Registry::get('aaa'));
var_dump(Yaf_Registry::get('bbb'));

輸出

int(111)
bool(true)
bool(true)
bool(false)
NULL
object(stdClass)#2 (0) {
}