diff core/modules/field/src/Entity/FieldStorageConfig.php @ 0:4c8ae668cc8c

Initial import (non-working)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/modules/field/src/Entity/FieldStorageConfig.php	Wed Nov 29 16:09:58 2017 +0000
@@ -0,0 +1,843 @@
+<?php
+
+namespace Drupal\field\Entity;
+
+use Drupal\Component\Utility\Unicode;
+use Drupal\Core\Config\Entity\ConfigEntityBase;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Entity\FieldableEntityStorageInterface;
+use Drupal\Core\Field\FieldException;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\TypedData\OptionsProviderInterface;
+use Drupal\field\FieldStorageConfigInterface;
+
+/**
+ * Defines the Field storage configuration entity.
+ *
+ * @ConfigEntityType(
+ *   id = "field_storage_config",
+ *   label = @Translation("Field storage"),
+ *   handlers = {
+ *     "access" = "Drupal\field\FieldStorageConfigAccessControlHandler",
+ *     "storage" = "Drupal\field\FieldStorageConfigStorage"
+ *   },
+ *   config_prefix = "storage",
+ *   entity_keys = {
+ *     "id" = "id",
+ *     "label" = "id"
+ *   },
+ *   config_export = {
+ *     "id",
+ *     "field_name",
+ *     "entity_type",
+ *     "type",
+ *     "settings",
+ *     "module",
+ *     "locked",
+ *     "cardinality",
+ *     "translatable",
+ *     "indexes",
+ *     "persist_with_no_fields",
+ *     "custom_storage",
+ *   }
+ * )
+ */
+class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigInterface {
+
+  /**
+   * The maximum length of the field name, in characters.
+   *
+   * For fields created through Field UI, this includes the 'field_' prefix.
+   */
+  const NAME_MAX_LENGTH = 32;
+
+  /**
+   * The field ID.
+   *
+   * The ID consists of 2 parts: the entity type and the field name.
+   *
+   * Example: node.body, user.field_main_image.
+   *
+   * @var string
+   */
+  protected $id;
+
+  /**
+   * The field name.
+   *
+   * This is the name of the property under which the field values are placed in
+   * an entity: $entity->{$field_name}. The maximum length is
+   * Field:NAME_MAX_LENGTH.
+   *
+   * Example: body, field_main_image.
+   *
+   * @var string
+   */
+  protected $field_name;
+
+  /**
+   * The name of the entity type the field can be attached to.
+   *
+   * @var string
+   */
+  protected $entity_type;
+
+  /**
+   * The field type.
+   *
+   * Example: text, integer.
+   *
+   * @var string
+   */
+  protected $type;
+
+  /**
+   * The name of the module that provides the field type.
+   *
+   * @var string
+   */
+  protected $module;
+
+  /**
+   * Field-type specific settings.
+   *
+   * An array of key/value pairs, The keys and default values are defined by the
+   * field type.
+   *
+   * @var array
+   */
+  protected $settings = [];
+
+  /**
+   * The field cardinality.
+   *
+   * The maximum number of values the field can hold. Possible values are
+   * positive integers or
+   * FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED. Defaults to 1.
+   *
+   * @var int
+   */
+  protected $cardinality = 1;
+
+  /**
+   * Flag indicating whether the field is translatable.
+   *
+   * Defaults to TRUE.
+   *
+   * @var bool
+   */
+  protected $translatable = TRUE;
+
+  /**
+   * Flag indicating whether the field is available for editing.
+   *
+   * If TRUE, some actions not available though the UI (but are still possible
+   * through direct API manipulation):
+   * - field settings cannot be changed,
+   * - new fields cannot be created
+   * - existing fields cannot be deleted.
+   * Defaults to FALSE.
+   *
+   * @var bool
+   */
+  protected $locked = FALSE;
+
+  /**
+   * Flag indicating whether the field storage should be deleted when orphaned.
+   *
+   * By default field storages for configurable fields are removed when there
+   * are no remaining fields using them. If multiple modules provide bundles
+   * which need to use the same field storage then setting this to TRUE will
+   * preserve the field storage regardless of what happens to the bundles. The
+   * classic use case for this is node body field storage since Book, Forum, the
+   * Standard profile and bundle (node type) creation through the UI all use
+   * same field storage.
+   *
+   * @var bool
+   */
+  protected $persist_with_no_fields = FALSE;
+
+  /**
+   * A boolean indicating whether or not the field item uses custom storage.
+   *
+   * @var bool
+   */
+  public $custom_storage = FALSE;
+
+  /**
+   * The custom storage indexes for the field data storage.
+   *
+   * This set of indexes is merged with the "default" indexes specified by the
+   * field type in hook_field_schema() to determine the actual set of indexes
+   * that get created.
+   *
+   * The indexes are defined using the same definition format as Schema API
+   * index specifications. Only columns that are part of the field schema, as
+   * defined by the field type in hook_field_schema(), are allowed.
+   *
+   * Some storage backends might not support indexes, and discard that
+   * information.
+   *
+   * @var array
+   */
+  protected $indexes = [];
+
+  /**
+   * Flag indicating whether the field is deleted.
+   *
+   * The delete() method marks the field as "deleted" and removes the
+   * corresponding entry from the config storage, but keeps its definition in
+   * the state storage while field data is purged by a separate
+   * garbage-collection process.
+   *
+   * Deleted fields stay out of the regular entity lifecycle (notably, their
+   * values are not populated in loaded entities, and are not saved back).
+   *
+   * @var bool
+   */
+  protected $deleted = FALSE;
+
+  /**
+   * The field schema.
+   *
+   * @var array
+   */
+  protected $schema;
+
+  /**
+   * An array of field property definitions.
+   *
+   * @var \Drupal\Core\TypedData\DataDefinitionInterface[]
+   *
+   * @see \Drupal\Core\TypedData\ComplexDataDefinitionInterface::getPropertyDefinitions()
+   */
+  protected $propertyDefinitions;
+
+  /**
+   * Static flag set to prevent recursion during field deletes.
+   *
+   * @var bool
+   */
+  protected static $inDeletion = FALSE;
+
+  /**
+   * Constructs a FieldStorageConfig object.
+   *
+   * In most cases, Field entities are created via
+   * FieldStorageConfig::create($values)), where $values is the same parameter
+   * as in this constructor.
+   *
+   * @param array $values
+   *   An array of field properties, keyed by property name. Most array
+   *   elements will be used to set the corresponding properties on the class;
+   *   see the class property documentation for details. Some array elements
+   *   have special meanings and a few are required. Special elements are:
+   *   - name: required. As a temporary Backwards Compatibility layer right now,
+   *     a 'field_name' property can be accepted in place of 'id'.
+   *   - entity_type: required.
+   *   - type: required.
+   *
+   * @see entity_create()
+   */
+  public function __construct(array $values, $entity_type = 'field_storage_config') {
+    // Check required properties.
+    if (empty($values['field_name'])) {
+      throw new FieldException('Attempt to create a field storage without a field name.');
+    }
+    if (!preg_match('/^[_a-z]+[_a-z0-9]*$/', $values['field_name'])) {
+      throw new FieldException("Attempt to create a field storage {$values['field_name']} with invalid characters. Only lowercase alphanumeric characters and underscores are allowed, and only lowercase letters and underscore are allowed as the first character");
+    }
+    if (empty($values['type'])) {
+      throw new FieldException("Attempt to create a field storage {$values['field_name']} with no type.");
+    }
+    if (empty($values['entity_type'])) {
+      throw new FieldException("Attempt to create a field storage {$values['field_name']} with no entity_type.");
+    }
+
+    parent::__construct($values, $entity_type);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function id() {
+    return $this->getTargetEntityTypeId() . '.' . $this->getName();
+  }
+
+  /**
+   * Overrides \Drupal\Core\Entity\Entity::preSave().
+   *
+   * @throws \Drupal\Core\Field\FieldException
+   *   If the field definition is invalid.
+   * @throws \Drupal\Core\Entity\EntityStorageException
+   *   In case of failures at the configuration storage level.
+   */
+  public function preSave(EntityStorageInterface $storage) {
+    // Clear the derived data about the field.
+    unset($this->schema);
+
+    // Filter out unknown settings and make sure all settings are present, so
+    // that a complete field definition is passed to the various hooks and
+    // written to config.
+    $field_type_manager = \Drupal::service('plugin.manager.field.field_type');
+    $default_settings = $field_type_manager->getDefaultStorageSettings($this->type);
+    $this->settings = array_intersect_key($this->settings, $default_settings) + $default_settings;
+
+    if ($this->isNew()) {
+      $this->preSaveNew($storage);
+    }
+    else {
+      $this->preSaveUpdated($storage);
+    }
+
+    parent::preSave($storage);
+  }
+
+  /**
+   * Prepares saving a new field definition.
+   *
+   * @param \Drupal\Core\Entity\EntityStorageInterface $storage
+   *   The entity storage.
+   *
+   * @throws \Drupal\Core\Field\FieldException
+   *   If the field definition is invalid.
+   */
+  protected function preSaveNew(EntityStorageInterface $storage) {
+    $entity_manager = \Drupal::entityManager();
+    $field_type_manager = \Drupal::service('plugin.manager.field.field_type');
+
+    // Assign the ID.
+    $this->id = $this->id();
+
+    // Field name cannot be longer than FieldStorageConfig::NAME_MAX_LENGTH characters.
+    // We use Unicode::strlen() because the DB layer assumes that column widths
+    // are given in characters rather than bytes.
+    if (Unicode::strlen($this->getName()) > static::NAME_MAX_LENGTH) {
+      throw new FieldException('Attempt to create a field storage with an name longer than ' . static::NAME_MAX_LENGTH . ' characters: ' . $this->getName());
+    }
+
+    // Disallow reserved field names.
+    $disallowed_field_names = array_keys($entity_manager->getBaseFieldDefinitions($this->getTargetEntityTypeId()));
+    if (in_array($this->getName(), $disallowed_field_names)) {
+      throw new FieldException("Attempt to create field storage {$this->getName()} which is reserved by entity type {$this->getTargetEntityTypeId()}.");
+    }
+
+    // Check that the field type is known.
+    $field_type = $field_type_manager->getDefinition($this->getType(), FALSE);
+    if (!$field_type) {
+      throw new FieldException("Attempt to create a field storage of unknown type {$this->getType()}.");
+    }
+    $this->module = $field_type['provider'];
+
+    // Notify the entity manager.
+    $entity_manager->onFieldStorageDefinitionCreate($this);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function calculateDependencies() {
+    parent::calculateDependencies();
+    // Ensure the field is dependent on the providing module.
+    $this->addDependency('module', $this->getTypeProvider());
+    // Ask the field type for any additional storage dependencies.
+    // @see \Drupal\Core\Field\FieldItemInterface::calculateStorageDependencies()
+    $definition = \Drupal::service('plugin.manager.field.field_type')->getDefinition($this->getType(), FALSE);
+    $this->addDependencies($definition['class']::calculateStorageDependencies($this));
+
+    // Ensure the field is dependent on the provider of the entity type.
+    $entity_type = \Drupal::entityManager()->getDefinition($this->entity_type);
+    $this->addDependency('module', $entity_type->getProvider());
+    return $this;
+  }
+
+  /**
+   * Prepares saving an updated field definition.
+   *
+   * @param \Drupal\Core\Entity\EntityStorageInterface $storage
+   *   The entity storage.
+   */
+  protected function preSaveUpdated(EntityStorageInterface $storage) {
+    $module_handler = \Drupal::moduleHandler();
+    $entity_manager = \Drupal::entityManager();
+
+    // Some updates are always disallowed.
+    if ($this->getType() != $this->original->getType()) {
+      throw new FieldException("Cannot change the field type for an existing field storage.");
+    }
+    if ($this->getTargetEntityTypeId() != $this->original->getTargetEntityTypeId()) {
+      throw new FieldException("Cannot change the entity type for an existing field storage.");
+    }
+
+    // See if any module forbids the update by throwing an exception. This
+    // invokes hook_field_storage_config_update_forbid().
+    $module_handler->invokeAll('field_storage_config_update_forbid', [$this, $this->original]);
+
+    // Notify the entity manager. A listener can reject the definition
+    // update as invalid by raising an exception, which stops execution before
+    // the definition is written to config.
+    $entity_manager->onFieldStorageDefinitionUpdate($this, $this->original);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function postSave(EntityStorageInterface $storage, $update = TRUE) {
+    if ($update) {
+      // Invalidate the render cache for all affected entities.
+      $entity_manager = \Drupal::entityManager();
+      $entity_type = $this->getTargetEntityTypeId();
+      if ($entity_manager->hasHandler($entity_type, 'view_builder')) {
+        $entity_manager->getViewBuilder($entity_type)->resetCache();
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function preDelete(EntityStorageInterface $storage, array $field_storages) {
+    $state = \Drupal::state();
+
+    // Set the static flag so that we don't delete field storages whilst
+    // deleting fields.
+    static::$inDeletion = TRUE;
+
+    // Delete or fix any configuration that is dependent, for example, fields.
+    parent::preDelete($storage, $field_storages);
+
+    // Keep the field definitions in the state storage so we can use them later
+    // during field_purge_batch().
+    $deleted_storages = $state->get('field.storage.deleted') ?: [];
+    /** @var \Drupal\field\FieldStorageConfigInterface $field_storage */
+    foreach ($field_storages as $field_storage) {
+      // Only mark a field for purging if there is data. Otherwise, just remove
+      // it.
+      $target_entity_storage = \Drupal::entityTypeManager()->getStorage($field_storage->getTargetEntityTypeId());
+      if (!$field_storage->deleted && $target_entity_storage instanceof FieldableEntityStorageInterface && $target_entity_storage->countFieldData($field_storage, TRUE)) {
+        $config = $field_storage->toArray();
+        $config['deleted'] = TRUE;
+        $config['bundles'] = $field_storage->getBundles();
+        $deleted_storages[$field_storage->uuid()] = $config;
+      }
+    }
+
+    $state->set('field.storage.deleted', $deleted_storages);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function postDelete(EntityStorageInterface $storage, array $fields) {
+    // Notify the storage.
+    foreach ($fields as $field) {
+      if (!$field->deleted) {
+        \Drupal::entityManager()->onFieldStorageDefinitionDelete($field);
+        $field->deleted = TRUE;
+      }
+    }
+    // Unset static flag.
+    static::$inDeletion = FALSE;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getSchema() {
+    if (!isset($this->schema)) {
+      // Get the schema from the field item class.
+      $class = $this->getFieldItemClass();
+      $schema = $class::schema($this);
+      // Fill in default values for optional entries.
+      $schema += [
+        'columns' => [],
+        'unique keys' => [],
+        'indexes' => [],
+        'foreign keys' => [],
+      ];
+
+      // Merge custom indexes with those specified by the field type. Custom
+      // indexes prevail.
+      $schema['indexes'] = $this->indexes + $schema['indexes'];
+
+      $this->schema = $schema;
+    }
+
+    return $this->schema;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function hasCustomStorage() {
+    return $this->custom_storage;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isBaseField() {
+    return FALSE;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getColumns() {
+    $schema = $this->getSchema();
+    // A typical use case for the method is to iterate on the columns, while
+    // some other use cases rely on identifying the first column with the key()
+    // function. Since the schema is persisted in the Field object, we take care
+    // of resetting the array pointer so that the former does not interfere with
+    // the latter.
+    reset($schema['columns']);
+    return $schema['columns'];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getBundles() {
+    if (!$this->isDeleted()) {
+      $map = \Drupal::entityManager()->getFieldMap();
+      if (isset($map[$this->getTargetEntityTypeId()][$this->getName()]['bundles'])) {
+        return $map[$this->getTargetEntityTypeId()][$this->getName()]['bundles'];
+      }
+    }
+    return [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getName() {
+    return $this->field_name;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isDeleted() {
+    return $this->deleted;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getTypeProvider() {
+    return $this->module;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getType() {
+    return $this->type;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getSettings() {
+    // @todo FieldTypePluginManager maintains its own static cache. However, do
+    //   some CPU and memory profiling to see if it's worth statically caching
+    //   $field_type_info, or the default field storage and field settings,
+    //   within $this.
+    $field_type_manager = \Drupal::service('plugin.manager.field.field_type');
+
+    $settings = $field_type_manager->getDefaultStorageSettings($this->getType());
+    return $this->settings + $settings;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getSetting($setting_name) {
+    // @todo See getSettings() about potentially statically caching this.
+    // We assume here that one call to array_key_exists() is more efficient
+    // than calling getSettings() when all we need is a single setting.
+    if (array_key_exists($setting_name, $this->settings)) {
+      return $this->settings[$setting_name];
+    }
+    $settings = $this->getSettings();
+    if (array_key_exists($setting_name, $settings)) {
+      return $settings[$setting_name];
+    }
+    else {
+      return NULL;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setSetting($setting_name, $value) {
+    $this->settings[$setting_name] = $value;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setSettings(array $settings) {
+    $this->settings = $settings + $this->settings;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isTranslatable() {
+    return $this->translatable;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isRevisionable() {
+    // All configurable fields are revisionable.
+    return TRUE;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setTranslatable($translatable) {
+    $this->translatable = $translatable;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getProvider() {
+    return 'field';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getLabel() {
+    return $this->label();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDescription() {
+    return NULL;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCardinality() {
+    /** @var \Drupal\Core\Field\FieldTypePluginManager $field_type_manager */
+    $field_type_manager = \Drupal::service('plugin.manager.field.field_type');
+    $definition = $field_type_manager->getDefinition($this->getType());
+    $enforced_cardinality = isset($definition['cardinality']) ? $definition['cardinality'] : NULL;
+
+    // Enforced cardinality is a positive integer or -1.
+    if ($enforced_cardinality !== NULL && $enforced_cardinality < 1 && $enforced_cardinality !== FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED) {
+      throw new FieldException("Invalid enforced cardinality '$enforced_cardinality'. Allowed values: a positive integer or -1.");
+    }
+
+    return $enforced_cardinality ?: $this->cardinality;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setCardinality($cardinality) {
+    $this->cardinality = $cardinality;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getOptionsProvider($property_name, FieldableEntityInterface $entity) {
+    // If the field item class implements the interface, create an orphaned
+    // runtime item object, so that it can be used as the options provider
+    // without modifying the entity being worked on.
+    if (is_subclass_of($this->getFieldItemClass(), OptionsProviderInterface::class)) {
+      $items = $entity->get($this->getName());
+      return \Drupal::service('plugin.manager.field.field_type')->createFieldItem($items, 0);
+    }
+    // @todo: Allow setting custom options provider, see
+    // https://www.drupal.org/node/2002138.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isMultiple() {
+    $cardinality = $this->getCardinality();
+    return ($cardinality == FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED) || ($cardinality > 1);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isLocked() {
+    return $this->locked;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setLocked($locked) {
+    $this->locked = $locked;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getTargetEntityTypeId() {
+    return $this->entity_type;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isQueryable() {
+    return TRUE;
+  }
+
+  /**
+   * Determines whether a field has any data.
+   *
+   * @return bool
+   *   TRUE if the field has data for any entity; FALSE otherwise.
+   */
+  public function hasData() {
+    return \Drupal::entityManager()->getStorage($this->entity_type)->countFieldData($this, TRUE);
+  }
+
+  /**
+   * Implements the magic __sleep() method.
+   *
+   * Using the Serialize interface and serialize() / unserialize() methods
+   * breaks entity forms in PHP 5.4.
+   * @todo Investigate in https://www.drupal.org/node/2074253.
+   */
+  public function __sleep() {
+    // Only serialize necessary properties, excluding those that can be
+    // recalculated.
+    $properties = get_object_vars($this);
+    unset($properties['schema'], $properties['propertyDefinitions'], $properties['original']);
+    return array_keys($properties);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getConstraints() {
+    return [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getConstraint($constraint_name) {
+    return NULL;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPropertyDefinition($name) {
+    if (!isset($this->propertyDefinitions)) {
+      $this->getPropertyDefinitions();
+    }
+    if (isset($this->propertyDefinitions[$name])) {
+      return $this->propertyDefinitions[$name];
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPropertyDefinitions() {
+    if (!isset($this->propertyDefinitions)) {
+      $class = $this->getFieldItemClass();
+      $this->propertyDefinitions = $class::propertyDefinitions($this);
+    }
+    return $this->propertyDefinitions;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPropertyNames() {
+    return array_keys($this->getPropertyDefinitions());
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getMainPropertyName() {
+    $class = $this->getFieldItemClass();
+    return $class::mainPropertyName();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getUniqueStorageIdentifier() {
+    return $this->uuid();
+  }
+
+  /**
+   * Helper to retrieve the field item class.
+   */
+  protected function getFieldItemClass() {
+    $type_definition = \Drupal::typedDataManager()
+      ->getDefinition('field_item:' . $this->getType());
+    return $type_definition['class'];
+  }
+
+  /**
+   * Loads a field config entity based on the entity type and field name.
+   *
+   * @param string $entity_type_id
+   *   ID of the entity type.
+   * @param string $field_name
+   *   Name of the field.
+   *
+   * @return static
+   *   The field config entity if one exists for the provided field name,
+   *   otherwise NULL.
+   */
+  public static function loadByName($entity_type_id, $field_name) {
+    return \Drupal::entityManager()->getStorage('field_storage_config')->load($entity_type_id . '.' . $field_name);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isDeletable() {
+    // The field storage is not deleted, is configured to be removed when there
+    // are no fields, the field storage has no bundles, and field storages are
+    // not in the process of being deleted.
+    return !$this->deleted && !$this->persist_with_no_fields && count($this->getBundles()) == 0 && !static::$inDeletion;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getIndexes() {
+    return $this->indexes;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setIndexes(array $indexes) {
+    $this->indexes = $indexes;
+    return $this;
+  }
+
+}