原型模式（Prototype）

目的

相比正常创建一个对象 ( new Foo() )，首先创建一个原型，然后克隆它会更节省开销。

示例

  • 大数据量 ( 例如：通过 ORM 模型一次性往数据库插入 1,000,000 条数据 ) 。

UML 图

file

代码

完整代码请看 GitHub

BookPrototype.php

  2. <?php
  4. namespace DesignPatterns\Creational\Prototype;
  6. abstract class BookPrototype
  7. {
  8.     /**
  9.     * @var string
  10.     */
  11.     protected $title;
  13.     /**
  14.     * @var string
  15.     */
  16.     protected $category;
  18.     abstract public function __clone();
  20.     public function getTitle(): string
  21.     {
  22.         return $this->title;
  23.     }
  25.     public function setTitle($title)
  26.     {
  27.         $this->title = $title;
  28.     }
  29. }

BarBookPrototype.php

  2. <?php
  4. namespace DesignPatterns\Creational\Prototype;
  6. class BarBookPrototype extends BookPrototype
  7. {
  8.     /**
  9.     * @var string
  10.     */
  11.     protected $category = 'Bar';
  13.     public function __clone()
  14.     {
  15.     }
  16. }

FooBookPrototype.php

  2. <?php
  4. namespace DesignPatterns\Creational\Prototype;
  6. class FooBookPrototype extends BookPrototype
  7. {
  8.     /**
  9.     * @var string
  10.     */
  11.     protected $category = 'Foo';
  13.     public function __clone()
  14.     {
  15.     }
  16. }

测试

Tests/PrototypeTest.php

  2. <?php
  4. namespace DesignPatterns\Creational\Prototype\Tests;
  6. use DesignPatterns\Creational\Prototype\BarBookPrototype;
  7. use DesignPatterns\Creational\Prototype\FooBookPrototype;
  8. use PHPUnit\Framework\TestCase;
  10. class PrototypeTest extends TestCase
  11. {
  12.     public function testCanGetFooBook()
  13.     {
  14.         $fooPrototype = new FooBookPrototype();
  15.         $barPrototype = new BarBookPrototype();
  17.         for ($i = 0; $i < 10; $i++) {
  18.             $book = clone $fooPrototype;
  19.             $book->setTitle('Foo Book No ' . $i);
  20.             $this->assertInstanceOf(FooBookPrototype::class, $book);
  21.         }
  23.         for ($i = 0; $i < 5; $i++) {
  24.             $book = clone $barPrototype;
  25.             $book->setTitle('Bar Book No ' . $i);
  26.             $this->assertInstanceOf(BarBookPrototype::class, $book);
  27.         }
  28.     }
  29. }