Chris@17: <?php
Chris@17: 
Chris@17: namespace Drupal\simpletest\Cache\Context;
Chris@17: 
Chris@17: use Drupal\Core\Cache\CacheableMetadata;
Chris@17: use Drupal\Core\Cache\Context\CacheContextInterface;
Chris@17: use Drupal\Core\PrivateKey;
Chris@17: use Drupal\Core\Site\Settings;
Chris@17: use Drupal\simpletest\TestDiscovery;
Chris@17: 
Chris@17: /**
Chris@17:  * Defines the TestDiscoveryCacheContext service.
Chris@17:  *
Chris@17:  * Cache context ID: 'test_discovery'.
Chris@17:  */
Chris@17: class TestDiscoveryCacheContext implements CacheContextInterface {
Chris@17: 
Chris@17:   /**
Chris@17:    * The test discovery service.
Chris@17:    *
Chris@17:    * @var \Drupal\simpletest\TestDiscovery
Chris@17:    */
Chris@17:   protected $testDiscovery;
Chris@17: 
Chris@17:   /**
Chris@17:    * The private key service.
Chris@17:    *
Chris@17:    * @var \Drupal\Core\PrivateKey
Chris@17:    */
Chris@17:   protected $privateKey;
Chris@17: 
Chris@17:   /**
Chris@17:    * The hash of discovered test information.
Chris@17:    *
Chris@17:    * Services should not be stateful, but we only keep this information per
Chris@17:    * request. That way we don't perform a file scan every time we need this
Chris@17:    * hash. The test scan results are unlikely to change during the request.
Chris@17:    *
Chris@17:    * @var string
Chris@17:    */
Chris@17:   protected $hash;
Chris@17: 
Chris@17:   /**
Chris@17:    * Construct a test discovery cache context.
Chris@17:    *
Chris@17:    * @param \Drupal\simpletest\TestDiscovery $test_discovery
Chris@17:    *   The test discovery service.
Chris@17:    * @param \Drupal\Core\PrivateKey $private_key
Chris@17:    *   The private key service.
Chris@17:    */
Chris@17:   public function __construct(TestDiscovery $test_discovery, PrivateKey $private_key) {
Chris@17:     $this->testDiscovery = $test_discovery;
Chris@17:     $this->privateKey = $private_key;
Chris@17:   }
Chris@17: 
Chris@17:   /**
Chris@17:    * {@inheritdoc}
Chris@17:    */
Chris@17:   public static function getLabel() {
Chris@17:     return t('Test discovery');
Chris@17:   }
Chris@17: 
Chris@17:   /**
Chris@17:    * {@inheritdoc}
Chris@17:    */
Chris@17:   public function getContext() {
Chris@17:     if (empty($this->hash)) {
Chris@17:       $tests = $this->testDiscovery->getTestClasses();
Chris@17:       $this->hash = $this->hash(serialize($tests));
Chris@17:     }
Chris@17:     return $this->hash;
Chris@17:   }
Chris@17: 
Chris@17:   /**
Chris@17:    * {@inheritdoc}
Chris@17:    */
Chris@17:   public function getCacheableMetadata() {
Chris@17:     return new CacheableMetadata();
Chris@17:   }
Chris@17: 
Chris@17:   /**
Chris@17:    * Hashes the given string.
Chris@17:    *
Chris@17:    * @param string $identifier
Chris@17:    *   The string to be hashed.
Chris@17:    *
Chris@17:    * @return string
Chris@17:    *   The hash.
Chris@17:    */
Chris@17:   protected function hash($identifier) {
Chris@17:     return hash('sha256', $this->privateKey->get() . Settings::getHashSalt() . $identifier);
Chris@17:   }
Chris@17: 
Chris@17: }