Issue #3044364 by amateescu: Improve hit ratio for the menu tree cache

core/lib/Drupal/Core/Menu/MenuTreeParameters.php

@@ -12,7 +12,7 @@
  *   a parent in the list will be included.
  * - Which menu links are omitted, depending on the minimum and maximum depth.
  */
-class MenuTreeParameters {
+class MenuTreeParameters implements \Serializable {
 
   /**
    * A menu link plugin ID that should be used as the root.
@@ -28,9 +28,6 @@ class MenuTreeParameters {
   /**
    * The minimum depth of menu links in the resulting tree relative to the root.
    *
-   * Defaults to 1, which is the default to build a whole tree for a menu
-   * (excluding the root).
-   *
    * @var int|null
    */
   public $minDepth = NULL;
@@ -211,4 +208,39 @@ public function excludeRoot() {
     return $this;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function serialize() {
+    // Enforce type consistency for all the internal properties of this object.
+    $this->root = (string) $this->root;
+    $this->minDepth = $this->minDepth !== NULL ? (int) $this->minDepth : NULL;
+    $this->maxDepth = $this->maxDepth !== NULL ? (int) $this->maxDepth : NULL;
+    $this->activeTrail = array_values(array_filter($this->activeTrail));
+
+    // Sort 'expanded' and 'conditions' to prevent duplicate cache items.
+    sort($this->expandedParents);
+    asort($this->conditions);
+
+    return serialize([
+      'root' => $this->root,
+      'minDepth' => $this->minDepth,
+      'maxDepth' => $this->maxDepth,
+      'expandedParents' => $this->expandedParents,
+      'activeTrail' => $this->activeTrail,
+      'conditions' => $this->conditions,
+    ]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function unserialize($serialized) {
+    foreach (unserialize($serialized) as $key => $value) {
+      $this->{$key} = $value;
+    }
+
+    return $this;
+  }
+
 }

core/lib/Drupal/Core/Menu/MenuTreeStorage.php

@@ -845,10 +845,6 @@ protected function saveRecursive($id, &$children, &$links) {
    * {@inheritdoc}
    */
   public function loadTreeData($menu_name, MenuTreeParameters $parameters) {
-    // Build the cache ID; sort 'expanded' and 'conditions' to prevent duplicate
-    // cache items.
-    sort($parameters->expandedParents);
-    asort($parameters->conditions);
     $tree_cid = "tree-data:$menu_name:" . serialize($parameters);
     $cache = $this->menuCacheBackend->get($tree_cid);
     if ($cache && isset($cache->data)) {

core/modules/system/system.post_update.php

@@ -190,3 +190,12 @@ function system_post_update_add_expand_all_items_key_in_system_menu_block(&$sand
     return strpos($block->getPluginId(), 'system_menu_block:') === 0;
   });
 }
+
+/**
+ * Clear the menu cache.
+ *
+ * @see https://www.drupal.org/project/drupal/issues/3044364
+ */
+function system_post_update_clear_menu_cache() {
+  // Empty post-update hook.
+}

core/tests/Drupal/Tests/Core/Menu/MenuTreeParametersTest.php

@@ -142,4 +142,24 @@ public function testExcludeRoot() {
     $this->assertEquals(1, $parameters->minDepth);
   }
 
+  /**
+   * @covers ::serialize
+   * @covers ::unserialize
+   */
+  public function testSerialize() {
+    $parameters = new MenuTreeParameters();
+    $parameters->setRoot(1);
+    $parameters->setMinDepth('2');
+    $parameters->setMaxDepth('9');
+    $parameters->addExpandedParents(['', 'foo']);
+    $parameters->setActiveTrail(['', 'bar']);
+
+    $after_serialize = unserialize(serialize($parameters));
+    $this->assertSame('1', $after_serialize->root);
+    $this->assertSame(2, $after_serialize->minDepth);
+    $this->assertSame(9, $after_serialize->maxDepth);
+    $this->assertSame(['', 'foo'], $after_serialize->expandedParents);
+    $this->assertSame(['bar'], $after_serialize->activeTrail);
+  }
+
 }