class NullBackend in Drupal 8

Defines a stub cache implementation.

The stub implementation is needed when database access is not yet available. Because Drupal's caching system never requires that cached data be present, these stub functions can short-circuit the process and sidestep the need for any persistent storage. Using this cache implementation during normal operations would have a negative impact on performance.

This also can be used for testing purposes.

Hierarchy

• class \Drupal\Core\Cache\NullBackend implements CacheBackendInterface

Related topics

Cache API

Information about the Drupal Cache API

8 files declare their use of NullBackend

CachedStorageTest.php in core/tests/Drupal/Tests/Core/Config/CachedStorageTest.php

ContextDefinitionIsSatisfiedTest.php in core/tests/Drupal/Tests/Core/Plugin/Context/ContextDefinitionIsSatisfiedTest.php

ContextHandlerTest.php in core/tests/Drupal/Tests/Core/Plugin/ContextHandlerTest.php

Contains \Drupal\Tests\Core\Plugin\ContextHandlerTest.

EntityContextDefinitionIsSatisfiedTest.php in core/tests/Drupal/Tests/Core/Plugin/Context/EntityContextDefinitionIsSatisfiedTest.php

NullBackendTest.php in core/tests/Drupal/Tests/Core/Cache/NullBackendTest.php

... See full list

File

core/lib/Drupal/Core/Cache/NullBackend.php, line 18

Namespace

Drupal\Core\Cache

class NullBackend implements CacheBackendInterface {

  /**
   * Constructs a NullBackend object.
   *
   * @param string $bin
   *   The cache bin for which the object is created.
   */
  public function __construct($bin) {
  }

  /**
   * {@inheritdoc}
   */
  public function get($cid, $allow_invalid = FALSE) {
    return FALSE;
  }

  /**
   * {@inheritdoc}
   */
  public function getMultiple(&$cids, $allow_invalid = FALSE) {
    return [];
  }

  /**
   * {@inheritdoc}
   */
  public function set($cid, $data, $expire = Cache::PERMANENT, array $tags = []) {
  }

  /**
   * {@inheritdoc}
   */
  public function setMultiple(array $items = []) {
  }

  /**
   * {@inheritdoc}
   */
  public function delete($cid) {
  }

  /**
   * {@inheritdoc}
   */
  public function deleteMultiple(array $cids) {
  }

  /**
   * {@inheritdoc}
   */
  public function deleteAll() {
  }

  /**
   * {@inheritdoc}
   */
  public function invalidate($cid) {
  }

  /**
   * {@inheritdoc}
   */
  public function invalidateMultiple(array $cids) {
  }

  /**
   * {@inheritdoc}
   */
  public function invalidateAll() {
  }

  /**
   * {@inheritdoc}
   */
  public function garbageCollection() {
  }

  /**
   * {@inheritdoc}
   */
  public function removeBin() {
  }

}

Members

Name	Modifiers	Type	Description	Overrides
CacheBackendInterface::CACHE_PERMANENT		constant	Indicates that the item should never be removed unless explicitly deleted.
NullBackend::delete	public	function	Deletes an item from the cache. Overrides CacheBackendInterface::delete	1
NullBackend::deleteAll	public	function	Deletes all cache items in a bin. Overrides CacheBackendInterface::deleteAll	1
NullBackend::deleteMultiple	public	function	Deletes multiple items from the cache. Overrides CacheBackendInterface::deleteMultiple	1
NullBackend::garbageCollection	public	function	Performs garbage collection on a cache bin. Overrides CacheBackendInterface::garbageCollection
NullBackend::get	public	function	Returns data from the persistent cache. Overrides CacheBackendInterface::get
NullBackend::getMultiple	public	function	Returns data from the persistent cache when given an array of cache IDs. Overrides CacheBackendInterface::getMultiple
NullBackend::invalidate	public	function	Marks a cache item as invalid. Overrides CacheBackendInterface::invalidate
NullBackend::invalidateAll	public	function	Marks all cache items as invalid. Overrides CacheBackendInterface::invalidateAll
NullBackend::invalidateMultiple	public	function	Marks cache items as invalid. Overrides CacheBackendInterface::invalidateMultiple
NullBackend::removeBin	public	function	Remove a cache bin. Overrides CacheBackendInterface::removeBin
NullBackend::set	public	function	Stores data in the persistent cache. Overrides CacheBackendInterface::set
NullBackend::setMultiple	public	function	Store multiple items in the persistent cache. Overrides CacheBackendInterface::setMultiple
NullBackend::__construct	public	function	Constructs a NullBackend object.	1