代理模式

定义：在客户端与实体之间建立一个代理对象(proxy),客户端对实体进行操作全部委派给代理对象，隐藏实体的具体实现细节

好处：代理对象（proxy）还可以与业务代码分离，部署到另外的服务器。业务代码中通过RPC来委派任务

$proxy = new \IMooc\Proxy();
$proxy->getUserName($id);
$proxy->setUserName($id, $name);

<?php
namespace IMooc;

interface IUserProxy
{
    function getUserName($id);
    function setUserName($id, $name);
}

<?php
namespace IMooc;

class Proxy implements IUserProxy
{

    function getUserName($id)
    {
        $db = Factory::createDatabase('slave');
        $db->query("select name from user where id = $id limit 1");
    }

    function setUserName($id, $name)
    {
        $db = Factory::createDatabase('master');
        $db->query("update user set name = $name where id = $id limit 1");
    }
}

来自为知笔记(Wiz)