BackendChainImplementationUnitTest.php

<?php

/**
 * @file
 * Definition of Drupal\system\Tests\Cache\BackendChainImplementationUnitTest.
 */
namespace Drupal\system\Tests\Cache;

use Drupal\Core\Cache\CacheBackendInterface;
use Drupal\Core\Cache\BackendChain;
use Drupal\Core\Cache\MemoryBackend;
use Drupal\simpletest\UnitTestBase;

/**
 * Tests implementation-specific functionality of the BackendChain backend.
 */
class BackendChainImplementationUnitTest extends UnitTestBase {
  public static function getInfo() {
    return array(
      'name' => 'Backend chain implementation',
      'description' => 'Unit test of backend chain implementation specifics.',
      'group' => 'Cache',
    );
  }

  /**
   * Chain that will be heavily tested.
   *
   * @var Drupal\Core\Cache\BackendChain
   */
  protected $chain;

  /**
   * First backend in the chain.
   *
   * @var Drupal\Core\Cache\CacheBackendInterface
   */
  protected $firstBackend;

  /**
   * Second backend in the chain.
   *
   * @var Drupal\Core\Cache\CacheBackendInterface
   */
  protected $secondBackend;

  /**
   * Third backend in the chain.
   *
   * @var Drupal\Core\Cache\CacheBackendInterface
   */
  protected $thirdBackend;
  public function setUp() {
    parent::setUp();

    // Set up three memory backends to be used in the chain.
    $this->firstBackend = new MemoryBackend('foo');
    $this->secondBackend = new MemoryBackend('bar');
    $this->thirdBackend = new MemoryBackend('baz');

    // Set an initial fixed dataset for all testing. The next three data
    // collections will test two edge cases (last backend has the data, and
    // first backend has the data) and will test a normal use case (middle
    // backend has the data). We should have a complete unit test with those.
    // Note that in all cases, when the same key is set on more than one
    // backend, the values are voluntarily different, this ensures in which
    // backend we actually fetched the key when doing get calls.
    // Set a key present on all backends (for delete).
    $this->firstBackend
      ->set('t123', 1231);
    $this->secondBackend
      ->set('t123', 1232);
    $this->thirdBackend
      ->set('t123', 1233);

    // Set a key present on the second and the third (for get), those two will
    // be different, this will ensure from where we get the key.
    $this->secondBackend
      ->set('t23', 232);
    $this->thirdBackend
      ->set('t23', 233);

    // Set a key on only the third, we will ensure propagation using this one.
    $this->thirdBackend
      ->set('t3', 33);

    // Create the chain.
    $this->chain = new BackendChain('foobarbaz');
    $this->chain
      ->appendBackend($this->firstBackend)
      ->appendBackend($this->secondBackend)
      ->appendBackend($this->thirdBackend);
  }

  /**
   * Test the get feature.
   */
  public function testGet() {
    $cached = $this->chain
      ->get('t123');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Got key that is on all backends');
    $this
      ->assertIdentical(1231, $cached->data, 'Got the key from the backend 1');
    $cached = $this->chain
      ->get('t23');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Got key that is on backends 2 and 3');
    $this
      ->assertIdentical(232, $cached->data, 'Got the key from the backend 2');
    $cached = $this->chain
      ->get('t3');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Got key that is on the backend 3');
    $this
      ->assertIdentical(33, $cached->data, 'Got the key from the backend 3');
  }

  /**
   * Test the get multiple feature.
   */
  public function testGetMultiple() {
    $cids = array(
      't123',
      't23',
      't3',
      't4',
    );
    $ret = $this->chain
      ->getMultiple($cids);
    $this
      ->assertIdentical($ret['t123']->data, 1231, 'Got key 123 and value is from the first backend');
    $this
      ->assertIdentical($ret['t23']->data, 232, 'Got key 23 and value is from the second backend');
    $this
      ->assertIdentical($ret['t3']->data, 33, 'Got key 3 and value is from the third backend');
    $this
      ->assertFalse(array_key_exists('t4', $ret), "Didn't get the nonexistent key");
    $this
      ->assertFalse(in_array('t123', $cids), "Existing key 123 has been removed from &\$cids");
    $this
      ->assertFalse(in_array('t23', $cids), "Existing key 23 has been removed from &\$cids");
    $this
      ->assertFalse(in_array('t3', $cids), "Existing key 3 has been removed from &\$cids");
    $this
      ->assert(in_array('t4', $cids), "Non existing key 4 is still in &\$cids");
  }

  /**
   * Test that set will propagate.
   */
  public function testSet() {
    $this->chain
      ->set('test', 123);
    $cached = $this->firstBackend
      ->get('test');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test key is in the first backend');
    $this
      ->assertIdentical(123, $cached->data, 'Test key has the right value');
    $cached = $this->secondBackend
      ->get('test');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test key is in the second backend');
    $this
      ->assertIdentical(123, $cached->data, 'Test key has the right value');
    $cached = $this->thirdBackend
      ->get('test');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test key is in the third backend');
    $this
      ->assertIdentical(123, $cached->data, 'Test key has the right value');
  }

  /**
   * Test that delete will propagate.
   */
  public function testDelete() {
    $this->chain
      ->set('test', 5);
    $cached = $this->firstBackend
      ->get('test');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test key has been added to the first backend');
    $cached = $this->secondBackend
      ->get('test');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test key has been added to the first backend');
    $cached = $this->thirdBackend
      ->get('test');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test key has been added to the first backend');
    $this->chain
      ->delete('test');
    $cached = $this->firstBackend
      ->get('test');
    $this
      ->assertIdentical(FALSE, $cached, 'Test key is removed from the first backend');
    $cached = $this->secondBackend
      ->get('test');
    $this
      ->assertIdentical(FALSE, $cached, 'Test key is removed from the second backend');
    $cached = $this->thirdBackend
      ->get('test');
    $this
      ->assertIdentical(FALSE, $cached, 'Test key is removed from the third backend');
  }

  /**
   * Ensure get values propagation to previous backends.
   */
  public function testGetHasPropagated() {
    $this->chain
      ->get('t23');
    $cached = $this->firstBackend
      ->get('t23');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test 2 has been propagated to the first backend');
    $this->chain
      ->get('t3');
    $cached = $this->firstBackend
      ->get('t3');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test 3 has been propagated to the first backend');
    $cached = $this->secondBackend
      ->get('t3');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test 3 has been propagated to the second backend');
  }

  /**
   * Ensure get multiple values propagation to previous backends.
   */
  public function testGetMultipleHasPropagated() {
    $cids = array(
      't3',
      't23',
    );
    $this->chain
      ->getMultiple($cids);
    $cached = $this->firstBackend
      ->get('t3');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test 3 has been propagated to the first backend');
    $this
      ->assertIdentical(33, $cached->data, 'And value has been kept');
    $cached = $this->secondBackend
      ->get('t3');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test 3 has been propagated to the second backend');
    $this
      ->assertIdentical(33, $cached->data, 'And value has been kept');
    $cached = $this->firstBackend
      ->get('t23');
    $this
      ->assertNotIdentical(FALSE, $cached, 'Test 2 has been propagated to the first backend');
    $this
      ->assertIdentical(232, $cached->data, 'And value has been kept');
  }

  /**
   * Test that the chain is not empty when at least one backend has data.
   */
  public function testNotEmptyIfOneBackendHasTheKey() {
    $this
      ->assertFalse($this->chain
      ->isEmpty(), 'Chain is not empty');

    // This is the only test that needs to start with an empty chain.
    $this->chain
      ->deleteAll();
    $this
      ->assert($this->chain
      ->isEmpty(), 'Chain have been emptied by the deleteAll() call');
    $this->secondBackend
      ->set('test', 5);
    $this
      ->assertFalse($this->chain
      ->isEmpty(), 'Chain is not empty anymore now that the second backend has something');
  }

  /**
   * Test that the delete all operation is propagated to all backends in the chain.
   */
  public function testDeleteAllPropagation() {

    // Set both expiring and permanent keys.
    $this->chain
      ->set('test1', 1, CacheBackendInterface::CACHE_PERMANENT);
    $this->chain
      ->set('test2', 3, time() + 1000);
    $this->chain
      ->deleteAll();
    $this
      ->assertTrue($this->firstBackend
      ->isEmpty(), 'First backend is empty after delete all.');
    $this
      ->assertTrue($this->secondBackend
      ->isEmpty(), 'Second backend is empty after delete all.');
    $this
      ->assertTrue($this->thirdBackend
      ->isEmpty(), 'Third backend is empty after delete all.');
  }

  /**
   * Test that the delete tags operation is propagated to all backends
   * in the chain.
   */
  public function testDeleteTagsPropagation() {

    // Create two cache entries with the same tag and tag value.
    $this->chain
      ->set('test_cid_clear1', 'foo', CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => 2,
    ));
    $this->chain
      ->set('test_cid_clear2', 'foo', CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => 2,
    ));
    $this
      ->assertNotIdentical(FALSE, $this->firstBackend
      ->get('test_cid_clear1') && $this->firstBackend
      ->get('test_cid_clear2') && $this->secondBackend
      ->get('test_cid_clear1') && $this->secondBackend
      ->get('test_cid_clear2') && $this->thirdBackend
      ->get('test_cid_clear1') && $this->thirdBackend
      ->get('test_cid_clear2'), 'Two cache items were created in all backends.');

    // Invalidate test_tag of value 1. This should invalidate both entries.
    $this->chain
      ->deleteTags(array(
      'test_tag' => 2,
    ));
    $this
      ->assertIdentical(FALSE, $this->firstBackend
      ->get('test_cid_clear1') && $this->firstBackend
      ->get('test_cid_clear2') && $this->secondBackend
      ->get('test_cid_clear1') && $this->secondBackend
      ->get('test_cid_clear2') && $this->thirdBackend
      ->get('test_cid_clear1') && $this->thirdBackend
      ->get('test_cid_clear2'), 'Two caches removed from all backends after clearing a cache tag.');

    // Create two cache entries with the same tag and an array tag value.
    $this->chain
      ->set('test_cid_clear1', 'foo', CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        1,
      ),
    ));
    $this->chain
      ->set('test_cid_clear2', 'foo', CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        1,
      ),
    ));
    $this
      ->assertNotIdentical(FALSE, $this->firstBackend
      ->get('test_cid_clear1') && $this->firstBackend
      ->get('test_cid_clear2') && $this->secondBackend
      ->get('test_cid_clear1') && $this->secondBackend
      ->get('test_cid_clear2') && $this->thirdBackend
      ->get('test_cid_clear1') && $this->thirdBackend
      ->get('test_cid_clear2'), 'Two cache items were created in all backends.');

    // Invalidate test_tag of value 1. This should invalidate both entries.
    $this->chain
      ->deleteTags(array(
      'test_tag' => array(
        1,
      ),
    ));
    $this
      ->assertIdentical(FALSE, $this->firstBackend
      ->get('test_cid_clear1') && $this->firstBackend
      ->get('test_cid_clear2') && $this->secondBackend
      ->get('test_cid_clear1') && $this->secondBackend
      ->get('test_cid_clear2') && $this->thirdBackend
      ->get('test_cid_clear1') && $this->thirdBackend
      ->get('test_cid_clear2'), 'Two caches removed from all backends after clearing a cache tag.');

    // Create three cache entries with a mix of tags and tag values.
    $this->chain
      ->set('test_cid_clear1', 'foo', CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        1,
      ),
    ));
    $this->chain
      ->set('test_cid_clear2', 'foo', CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag' => array(
        2,
      ),
    ));
    $this->chain
      ->set('test_cid_clear3', 'foo', CacheBackendInterface::CACHE_PERMANENT, array(
      'test_tag_foo' => array(
        3,
      ),
    ));
    $this
      ->assertNotIdentical(FALSE, $this->firstBackend
      ->get('test_cid_clear1') && $this->firstBackend
      ->get('test_cid_clear2') && $this->firstBackend
      ->get('test_cid_clear3') && $this->secondBackend
      ->get('test_cid_clear1') && $this->secondBackend
      ->get('test_cid_clear2') && $this->secondBackend
      ->get('test_cid_clear3') && $this->thirdBackend
      ->get('test_cid_clear1') && $this->thirdBackend
      ->get('test_cid_clear2') && $this->thirdBackend
      ->get('test_cid_clear3'), 'Three cached items were created in all backends.');
    $this->chain
      ->deleteTags(array(
      'test_tag_foo' => array(
        3,
      ),
    ));
    $this
      ->assertNotIdentical(FALSE, $this->firstBackend
      ->get('test_cid_clear1') && $this->firstBackend
      ->get('test_cid_clear2') && $this->secondBackend
      ->get('test_cid_clear1') && $this->secondBackend
      ->get('test_cid_clear2') && $this->thirdBackend
      ->get('test_cid_clear1') && $this->thirdBackend
      ->get('test_cid_clear2'), 'Cached items not matching the tag were not cleared from any of the backends.');
    $this
      ->assertIdentical(FALSE, $this->firstBackend
      ->get('test_cid_clear3') && $this->secondBackend
      ->get('test_cid_clear3') && $this->thirdBackend
      ->get('test_cid_clear3'), 'Cached item matching the tag was removed from all backends.');
  }

}