diff core/lib/Drupal/Core/Routing/RoutePreloader.php @ 0:4c8ae668cc8c

Initial import (non-working)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/lib/Drupal/Core/Routing/RoutePreloader.php	Wed Nov 29 16:09:58 2017 +0000
@@ -0,0 +1,133 @@
+<?php
+
+namespace Drupal\Core\Routing;
+
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\State\StateInterface;
+use Symfony\Component\EventDispatcher\Event;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Event\KernelEvent;
+use Symfony\Component\HttpKernel\KernelEvents;
+
+/**
+ * Defines a class which preloads non-admin routes.
+ *
+ * On an actual site we want to avoid too many database queries so we build a
+ * list of all routes which most likely appear on the actual site, which are all
+ * HTML routes not starting with "/admin".
+ */
+class RoutePreloader implements EventSubscriberInterface {
+
+  /**
+   * The route provider.
+   *
+   * @var \Drupal\Core\Routing\RouteProviderInterface|\Drupal\Core\Routing\PreloadableRouteProviderInterface
+   */
+  protected $routeProvider;
+
+  /**
+   * The state key value store.
+   *
+   * @var \Drupal\Core\State\StateInterface
+   */
+  protected $state;
+
+  /**
+   * Contains the non-admin routes while rebuilding the routes.
+   *
+   * @var array
+   */
+  protected $nonAdminRoutesOnRebuild = [];
+
+  /**
+   * The cache backend used to skip the state loading.
+   *
+   * @var \Drupal\Core\Cache\CacheBackendInterface
+   */
+  protected $cache;
+
+  /**
+   * Constructs a new RoutePreloader.
+   *
+   * @param \Drupal\Core\Routing\RouteProviderInterface $route_provider
+   *   The route provider.
+   * @param \Drupal\Core\State\StateInterface $state
+   *   The state key value store.
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache
+   */
+  public function __construct(RouteProviderInterface $route_provider, StateInterface $state, CacheBackendInterface $cache) {
+    $this->routeProvider = $route_provider;
+    $this->state = $state;
+    $this->cache = $cache;
+  }
+
+  /**
+   * Loads all non-admin routes right before the actual page is rendered.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\KernelEvent $event
+   *   The event to process.
+   */
+  public function onRequest(KernelEvent $event) {
+    // Only preload on normal HTML pages, as they will display menu links.
+    if ($this->routeProvider instanceof PreloadableRouteProviderInterface && $event->getRequest()->getRequestFormat() == 'html') {
+
+      // Ensure that the state query is cached to skip the database query, if
+      // possible.
+      $key = 'routing.non_admin_routes';
+      if ($cache = $this->cache->get($key)) {
+        $routes = $cache->data;
+      }
+      else {
+        $routes = $this->state->get($key, []);
+        $this->cache->set($key, $routes, Cache::PERMANENT, ['routes']);
+      }
+
+      if ($routes) {
+        // Preload all the non-admin routes at once.
+        $this->routeProvider->preLoadRoutes($routes);
+      }
+    }
+  }
+
+  /**
+   * Alters existing routes for a specific collection.
+   *
+   * @param \Drupal\Core\Routing\RouteBuildEvent $event
+   *   The route build event.
+   */
+  public function onAlterRoutes(RouteBuildEvent $event) {
+    $collection = $event->getRouteCollection();
+    foreach ($collection->all() as $name => $route) {
+      if (strpos($route->getPath(), '/admin/') !== 0 && $route->getPath() != '/admin') {
+        $this->nonAdminRoutesOnRebuild[] = $name;
+      }
+    }
+    $this->nonAdminRoutesOnRebuild = array_unique($this->nonAdminRoutesOnRebuild);
+  }
+
+  /**
+   * Store the non admin routes in state when the route building is finished.
+   *
+   * @param \Symfony\Component\EventDispatcher\Event $event
+   *   The route finish event.
+   */
+  public function onFinishedRoutes(Event $event) {
+    $this->state->set('routing.non_admin_routes', $this->nonAdminRoutesOnRebuild);
+    $this->nonAdminRoutesOnRebuild = [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() {
+    // Set a really low priority to catch as many as possible routes.
+    $events[RoutingEvents::ALTER] = ['onAlterRoutes', -1024];
+    $events[RoutingEvents::FINISHED] = ['onFinishedRoutes'];
+    // Load the routes before the controller is executed (which happens after
+    // the kernel request event).
+    $events[KernelEvents::REQUEST][] = ['onRequest'];
+    return $events;
+  }
+
+}