Version 1

[yaffs-website] / web / core / lib / Drupal / Core / Path / AliasWhitelist.php

diff --git a/web/core/lib/Drupal/Core/Path/AliasWhitelist.php b/web/core/lib/Drupal/Core/Path/AliasWhitelist.php
new file mode 100644 (file)
index 0000000..9286c95
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+++ b/web/core/lib/Drupal/Core/Path/AliasWhitelist.php
@@ -0,0 +1,120 @@
+<?php
+
+namespace Drupal\Core\Path;
+
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Cache\CacheCollector;
+use Drupal\Core\State\StateInterface;
+use Drupal\Core\Lock\LockBackendInterface;
+
+/**
+ * Extends CacheCollector to build the path alias whitelist over time.
+ */
+class AliasWhitelist extends CacheCollector implements AliasWhitelistInterface {
+
+  /**
+   * The Key/Value Store to use for state.
+   *
+   * @var \Drupal\Core\State\StateInterface
+   */
+  protected $state;
+
+  /**
+   * The Path CRUD service.
+   *
+   * @var \Drupal\Core\Path\AliasStorageInterface
+   */
+  protected $aliasStorage;
+
+  /**
+   * Constructs an AliasWhitelist object.
+   *
+   * @param string $cid
+   *   The cache id to use.
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache
+   *   The cache backend.
+   * @param \Drupal\Core\Lock\LockBackendInterface $lock
+   *   The lock backend.
+   * @param \Drupal\Core\State\StateInterface $state
+   *   The state keyvalue store.
+   * @param \Drupal\Core\Path\AliasStorageInterface $alias_storage
+   *   The alias storage service.
+   */
+  public function __construct($cid, CacheBackendInterface $cache, LockBackendInterface $lock, StateInterface $state, AliasStorageInterface $alias_storage) {
+    parent::__construct($cid, $cache, $lock);
+    $this->state = $state;
+    $this->aliasStorage = $alias_storage;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function lazyLoadCache() {
+    parent::lazyLoadCache();
+
+    // On a cold start $this->storage will be empty and the whitelist will
+    // need to be rebuilt from scratch. The whitelist is initialized from the
+    // list of all valid path roots stored in the 'router.path_roots' state,
+    // with values initialized to NULL. During the request, each path requested
+    // that matches one of these keys will be looked up and the array value set
+    // to either TRUE or FALSE. This ensures that paths which do not exist in
+    // the router are not looked up, and that paths that do exist in the router
+    // are only looked up once.
+    if (empty($this->storage)) {
+      $this->loadMenuPathRoots();
+    }
+  }
+
+  /**
+   * Loads menu path roots to prepopulate cache.
+   */
+  protected function loadMenuPathRoots() {
+    if ($roots = $this->state->get('router.path_roots')) {
+      foreach ($roots as $root) {
+        $this->storage[$root] = NULL;
+        $this->persist($root);
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function get($offset) {
+    $this->lazyLoadCache();
+    // this may be called with paths that are not represented by menu router
+    // items such as paths that will be rewritten by hook_url_outbound_alter().
+    // Therefore internally TRUE is used to indicate whitelisted paths. FALSE is
+    // used to indicate paths that have already been checked but are not
+    // whitelisted, and NULL indicates paths that have not been checked yet.
+    if (isset($this->storage[$offset])) {
+      if ($this->storage[$offset]) {
+        return TRUE;
+      }
+    }
+    elseif (array_key_exists($offset, $this->storage)) {
+      return $this->resolveCacheMiss($offset);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function resolveCacheMiss($root) {
+    $exists = $this->aliasStorage->pathHasMatchingAlias('/' . $root);
+    $this->storage[$root] = $exists;
+    $this->persist($root);
+    if ($exists) {
+      return TRUE;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function clear() {
+    parent::clear();
+    $this->loadMenuPathRoots();
+  }
+
+}