Issue #2926540 by amateescu, plach, xjm, hchonov, Berdir: Split revision-handling methods to a separate entity storage interface

core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php

@@ -132,13 +132,6 @@ class ConfigEntityStorage extends EntityStorageBase implements ConfigEntityStora
     return NULL;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function loadMultipleRevisions(array $revision_ids) {
-    return [];
-  }
-
   /**
    * {@inheritdoc}
    */

core/lib/Drupal/Core/Entity/ContentEntityStorageInterface.php

@@ -5,7 +5,7 @@ namespace Drupal\Core\Entity;
 /**
  * A storage that supports content entity types.
  */
-interface ContentEntityStorageInterface extends EntityStorageInterface {
+interface ContentEntityStorageInterface extends EntityStorageInterface, RevisionableStorageInterface {
 
   /**
    * Constructs a new entity translation object, without permanently saving it.

core/lib/Drupal/Core/Entity/EntityStorageInterface.php

@@ -79,21 +79,15 @@ interface EntityStorageInterface {
    *
    * @return \Drupal\Core\Entity\EntityInterface|null
    *   The specified entity revision or NULL if not found.
+   *
+   * @todo Deprecated in Drupal 8.5.0 and will be removed before Drupal 9.0.0.
+   *   Use \Drupal\Core\Entity\RevisionableStorageInterface instead.
+   *
+   * @see https://www.drupal.org/node/2926958
+   * @see https://www.drupal.org/node/2927226
    */
   public function loadRevision($revision_id);
 
-  /**
-   * Loads multiple entity revisions.
-   *
-   * @param array $revision_ids
-   *   An array of revision IDs to load.
-   *
-   * @return \Drupal\Core\Entity\EntityInterface[]
-   *   An array of entity revisions keyed by their revision ID, or an empty
-   *   array if none found.
-   */
-  public function loadMultipleRevisions(array $revision_ids);
-
   /**
    * Delete a specific entity revision.
    *
@@ -101,6 +95,12 @@ interface EntityStorageInterface {
    *
    * @param int $revision_id
    *   The revision id.
+   *
+   * @todo Deprecated in Drupal 8.5.0 and will be removed before Drupal 9.0.0.
+   *   Use \Drupal\Core\Entity\RevisionableStorageInterface instead.
+   *
+   * @see https://www.drupal.org/node/2926958
+   * @see https://www.drupal.org/node/2927226
    */
   public function deleteRevision($revision_id);
 

core/lib/Drupal/Core/Entity/KeyValueStore/KeyValueContentEntityStorage.php

@@ -23,4 +23,11 @@ class KeyValueContentEntityStorage extends KeyValueEntityStorage implements Cont
    */
   public function createWithSampleValues($bundle = FALSE, array $values = []) {}
 
+  /**
+   * {@inheritdoc}
+   */
+  public function loadMultipleRevisions(array $revision_ids) {
+    return [];
+  }
+
 }

core/lib/Drupal/Core/Entity/KeyValueStore/KeyValueEntityStorage.php

@@ -130,13 +130,6 @@ class KeyValueEntityStorage extends EntityStorageBase {
     return NULL;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function loadMultipleRevisions(array $revision_ids) {
-    return [];
-  }
-
   /**
    * {@inheritdoc}
    */

core/lib/Drupal/Core/Entity/RevisionableStorageInterface.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace Drupal\Core\Entity;
+
+/**
+ * A storage that supports revisionable entity types.
+ */
+interface RevisionableStorageInterface {
+
+  /**
+   * Loads a specific entity revision.
+   *
+   * @param int $revision_id
+   *   The revision ID.
+   *
+   * @return \Drupal\Core\Entity\EntityInterface|null
+   *   The specified entity revision or NULL if not found.
+   */
+  public function loadRevision($revision_id);
+
+  /**
+   * Loads multiple entity revisions.
+   *
+   * @param array $revision_ids
+   *   An array of revision IDs to load.
+   *
+   * @return \Drupal\Core\Entity\EntityInterface[]
+   *   An array of entity revisions keyed by their revision ID, or an empty
+   *   array if none found.
+   */
+  public function loadMultipleRevisions(array $revision_ids);
+
+  /**
+   * Deletes a specific entity revision.
+   *
+   * A revision can only be deleted if it's not the currently active one.
+   *
+   * @param int $revision_id
+   *   The revision ID.
+   */
+  public function deleteRevision($revision_id);
+
+}