管道模式

管道模式也叫流水线模式，对于管道模式来说，有三个对象，管道，载荷，过滤器（阀门）<br />再管道种对附载进行一系列的处理，因为可以对过滤器进行动态添加，所以对负载的处理可以变得更加灵活<br />但同时过滤器过多，很淡把握整体的处理逻辑，而且再某一个过滤器对载荷处理后，因为载荷改变，会造成下一个过滤器种的逻辑出现问题<br />![image.png](https://cdn.nlark.com/yuque/0/2021/png/22438777/1636365022018-d4c5294b-31dc-49cf-ab5b-9b897649b741.png#clientId=u9cf3090d-49a4-4&from=paste&height=442&id=u79f22593&margin=%5Bobject%20Object%5D&name=image.png&originHeight=442&originWidth=801&originalType=binary&ratio=1&size=23687&status=done&style=none&taskId=u5194cad4-27bf-4ec7-a7fe-75fe40a6ec0&width=801)

<?php
/**
 * 管道抽象类
 */
interface PipelineInterface
{
    //数据载荷
    public function __construct($payLoad);
    //添加过滤器
    public function pipe(StageInterface $stage);
    //执行
    public function process();
}
/**
 * 过滤器抽象类
 */
interface StageInterface
{
    //处理逻辑
    public function handle($payLoad);
}
/**
 * 过滤器A
 */
class StageA implements StageInterface
{
    public function handle($payLoad)
    {
        echo "StageAddHundred<pre>";
        return $payLoad + 100;
    }
}
class StageB implements StageInterface
{
    public function handle($payLoad)
    {
        echo "StageMultiHundred<pre>";
        return $payLoad * 100;
    }
}
/**
 * 管道实现类
 */
class Pipeline implements PipelineInterface
{
    private $pipes;
    private $payLoad;
    public function __construct($payLoad)
    {
        $this->payLoad = $payLoad;
    }
    public function pipe(StageInterface $stage)
    {
        $this->pipes[] = $stage;
        return $this;
    }
    public function process()
    {
        foreach ($this->pipes as $eachPipe) {
            //执行类方法
            $this->payLoad = call_user_func([
                $eachPipe,
                'handle'
            ], $this->payLoad);
        }
        return $this->payLoad;
    }
}
//操作类
class Test
{
    public function run()
    {
        $payLoad = 10;
        $StageA = new StageA();
        $StageB = new StageB();
        $pipe = new Pipeline($payLoad);
        return $pipe->pipe($StageA)
            ->pipe($StageB)
            ->process();
    }
}
$test = new Test();
echo '<pre>';
var_dump($test->run());