interface FieldableEntityStorageInterface

interface FieldableEntityStorageInterface extends EntityStorageInterface {
    
    /**
     * Determines the number of entities with values for a given field.
     *
     * @param \Drupal\Core\Field\FieldStorageDefinitionInterface $storage_definition
     *   The field for which to count data records.
     * @param bool $as_bool
     *   (Optional) Optimizes the query for checking whether there are any records
     *   or not. Defaults to FALSE.
     *
     * @return bool|int
     *   The number of entities. If $as_bool parameter is TRUE then the
     *   value will either be TRUE or FALSE.
     *
     * @see \Drupal\Core\Entity\FieldableEntityStorageInterface::purgeFieldData()
     */
    public function countFieldData($storage_definition, $as_bool = FALSE);
    
    /**
     * Purges a batch of field data.
     *
     * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
     *   The deleted field whose data is being purged.
     * @param int $batch_size
     *   The maximum number of field data records to purge before returning,
     *   relating to the count of field data records returned by
     *   \Drupal\Core\Entity\FieldableEntityStorageInterface::countFieldData().
     *
     * @return int
     *   The number of field data records that have been purged.
     */
    public function purgeFieldData(FieldDefinitionInterface $field_definition, $batch_size);
    
    /**
     * Performs final cleanup after all data of a field has been purged.
     *
     * @param \Drupal\Core\Field\FieldStorageDefinitionInterface $storage_definition
     *   The field storage being purged.
     */
    public function finalizePurge(FieldStorageDefinitionInterface $storage_definition);

}