[Form] Improved ChoiceType performance by caching ChoiceList objects

src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php

@@ -31,6 +31,12 @@ use Symfony\Component\OptionsResolver\OptionsResolverInterface;
 
 class ChoiceType extends AbstractType
 {
+    /**
+     * Caches created choice lists.
+     * @var array
+     */
+    private $choiceListCache = array();
+
     /**
      * {@inheritdoc}
      */
@@ -123,12 +129,20 @@ class ChoiceType extends AbstractType
      */
     public function setDefaultOptions(OptionsResolverInterface $resolver)
     {
-        $choiceList = function (Options $options) {
-            return new SimpleChoiceList(
-                // Harden against NULL values (like in EntityType and ModelType)
-                null !== $options['choices'] ? $options['choices'] : array(),
-                $options['preferred_choices']
-            );
+        $choiceListCache =& $this->choiceListCache;
+
+        $choiceList = function (Options $options) use (&$choiceListCache) {
+            // Harden against NULL values (like in EntityType and ModelType)
+            $choices = null !== $options['choices'] ? $options['choices'] : array();
+
+            // Reuse existing choice lists in order to increase performance
+            $hash = md5(json_encode(array($choices, $options['preferred_choices'])));
+
+            if (!isset($choiceListCache[$hash])) {
+                $choiceListCache[$hash] = new SimpleChoiceList($choices, $options['preferred_choices']);
+            }
+
+            return $choiceListCache[$hash];
         };
 
         $emptyData = function (Options $options) {

src/Symfony/Component/Form/Tests/Extension/Core/Type/ChoiceTypePerformanceTest.php

@@ -0,0 +1,36 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Tests\Extension\Core\Type;
+
+use Symfony\Component\Form\Tests\FormPerformanceTestCase;
+
+/**
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+class ChoiceTypePerformanceTest extends FormPerformanceTestCase
+{
+    /**
+     * This test case is realistic in collection forms where each
+     * row contains the same choice field.
+     */
+    public function testSameChoiceFieldCreatedMultipleTimes()
+    {
+        $this->setMaxRunningTime(1);
+        $choices = range(1, 300);
+
+        for ($i = 0; $i < 100; ++$i) {
+            $this->factory->create('choice', rand(1, 400), array(
+                'choices' => $choices,
+            ));
+        }
+    }
+}

src/Symfony/Component/Form/Tests/FormIntegrationTestCase.php

@@ -0,0 +1,42 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Tests;
+
+use Symfony\Component\Form\FormFactory;
+use Symfony\Component\Form\Extension\Core\CoreExtension;
+
+/**
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+class FormIntegrationTestCase extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var \Symfony\Component\Form\FormFactoryInterface
+     */
+    protected $factory;
+
+    protected function setUp()
+    {
+        if (!class_exists('Symfony\Component\EventDispatcher\EventDispatcher')) {
+            $this->markTestSkipped('The "EventDispatcher" component is not available');
+        }
+
+        $this->factory = new FormFactory($this->getExtensions());
+    }
+
+    protected function getExtensions()
+    {
+        return array(
+            new CoreExtension(),
+        );
+    }
+}

src/Symfony/Component/Form/Tests/FormPerformanceTestCase.php

@@ -0,0 +1,71 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Tests;
+
+/**
+ * Base class for performance tests.
+ *
+ * Copied from Doctrine 2's OrmPerformanceTestCase.
+ *
+ * @author robo
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+class FormPerformanceTestCase extends FormIntegrationTestCase
+{
+    /**
+     * @var    integer
+     */
+    protected $maxRunningTime = 0;
+
+    /**
+     */
+    protected function runTest()
+    {
+        $s = microtime(true);
+        parent::runTest();
+        $time = microtime(true) - $s;
+
+        if ($this->maxRunningTime != 0 && $time > $this->maxRunningTime) {
+            $this->fail(
+                sprintf(
+                    'expected running time: <= %s but was: %s',
+
+                    $this->maxRunningTime,
+                    $time
+                )
+            );
+        }
+    }
+
+    /**
+     * @param  integer $maxRunningTime
+     * @throws InvalidArgumentException
+     * @since  Method available since Release 2.3.0
+     */
+    public function setMaxRunningTime($maxRunningTime)
+    {
+        if (is_integer($maxRunningTime) && $maxRunningTime >= 0) {
+            $this->maxRunningTime = $maxRunningTime;
+        } else {
+            throw new \InvalidArgumentException;
+        }
+    }
+
+    /**
+     * @return integer
+     * @since  Method available since Release 2.3.0
+     */
+    public function getMaxRunningTime()
+    {
+        return $this->maxRunningTime;
+    }
+}