diff core/lib/Drupal/Core/Path/AliasManager.php @ 0:4c8ae668cc8c

Initial import (non-working)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/lib/Drupal/Core/Path/AliasManager.php	Wed Nov 29 16:09:58 2017 +0000
@@ -0,0 +1,300 @@
+<?php
+
+namespace Drupal\Core\Path;
+
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\CacheDecorator\CacheDecoratorInterface;
+use Drupal\Core\Language\LanguageInterface;
+use Drupal\Core\Language\LanguageManagerInterface;
+
+/**
+ * The default alias manager implementation.
+ */
+class AliasManager implements AliasManagerInterface, CacheDecoratorInterface {
+
+  /**
+   * The alias storage service.
+   *
+   * @var \Drupal\Core\Path\AliasStorageInterface
+   */
+  protected $storage;
+
+  /**
+   * Cache backend service.
+   *
+   * @var \Drupal\Core\Cache\CacheBackendInterface;
+   */
+  protected $cache;
+
+  /**
+   * The cache key to use when caching paths.
+   *
+   * @var string
+   */
+  protected $cacheKey;
+
+  /**
+   * Whether the cache needs to be written.
+   *
+   * @var bool
+   */
+  protected $cacheNeedsWriting = FALSE;
+
+  /**
+   * Language manager for retrieving the default langcode when none is specified.
+   *
+   * @var \Drupal\Core\Language\LanguageManagerInterface
+   */
+  protected $languageManager;
+
+  /**
+   * Holds the map of path lookups per language.
+   *
+   * @var array
+   */
+  protected $lookupMap = [];
+
+  /**
+   * Holds an array of aliases for which no path was found.
+   *
+   * @var array
+   */
+  protected $noPath = [];
+
+  /**
+   * Holds the array of whitelisted path aliases.
+   *
+   * @var \Drupal\Core\Path\AliasWhitelistInterface
+   */
+  protected $whitelist;
+
+  /**
+   * Holds an array of paths that have no alias.
+   *
+   * @var array
+   */
+  protected $noAlias = [];
+
+  /**
+   * Whether preloaded path lookups has already been loaded.
+   *
+   * @var array
+   */
+  protected $langcodePreloaded = [];
+
+  /**
+   * Holds an array of previously looked up paths for the current request path.
+   *
+   * This will only get populated if a cache key has been set, which for example
+   * happens if the alias manager is used in the context of a request.
+   *
+   * @var array
+   */
+  protected $preloadedPathLookups = FALSE;
+
+  /**
+   * Constructs an AliasManager.
+   *
+   * @param \Drupal\Core\Path\AliasStorageInterface $storage
+   *   The alias storage service.
+   * @param \Drupal\Core\Path\AliasWhitelistInterface $whitelist
+   *   The whitelist implementation to use.
+   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
+   *   The language manager.
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache
+   *   Cache backend.
+   */
+  public function __construct(AliasStorageInterface $storage, AliasWhitelistInterface $whitelist, LanguageManagerInterface $language_manager, CacheBackendInterface $cache) {
+    $this->storage = $storage;
+    $this->languageManager = $language_manager;
+    $this->whitelist = $whitelist;
+    $this->cache = $cache;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setCacheKey($key) {
+    // Prefix the cache key to avoid clashes with other caches.
+    $this->cacheKey = 'preload-paths:' . $key;
+  }
+
+  /**
+   * {@inheritdoc}
+   *
+   * Cache an array of the paths available on each page. We assume that aliases
+   * will be needed for the majority of these paths during subsequent requests,
+   * and load them in a single query during path alias lookup.
+   */
+  public function writeCache() {
+    // Check if the paths for this page were loaded from cache in this request
+    // to avoid writing to cache on every request.
+    if ($this->cacheNeedsWriting && !empty($this->cacheKey)) {
+      // Start with the preloaded path lookups, so that cached entries for other
+      // languages will not be lost.
+      $path_lookups = $this->preloadedPathLookups ?: [];
+      foreach ($this->lookupMap as $langcode => $lookups) {
+        $path_lookups[$langcode] = array_keys($lookups);
+        if (!empty($this->noAlias[$langcode])) {
+          $path_lookups[$langcode] = array_merge($path_lookups[$langcode], array_keys($this->noAlias[$langcode]));
+        }
+      }
+
+      $twenty_four_hours = 60 * 60 * 24;
+      $this->cache->set($this->cacheKey, $path_lookups, $this->getRequestTime() + $twenty_four_hours);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPathByAlias($alias, $langcode = NULL) {
+    // If no language is explicitly specified we default to the current URL
+    // language. If we used a language different from the one conveyed by the
+    // requested URL, we might end up being unable to check if there is a path
+    // alias matching the URL path.
+    $langcode = $langcode ?: $this->languageManager->getCurrentLanguage(LanguageInterface::TYPE_URL)->getId();
+
+    // If we already know that there are no paths for this alias simply return.
+    if (empty($alias) || !empty($this->noPath[$langcode][$alias])) {
+      return $alias;
+    }
+
+    // Look for the alias within the cached map.
+    if (isset($this->lookupMap[$langcode]) && ($path = array_search($alias, $this->lookupMap[$langcode]))) {
+      return $path;
+    }
+
+    // Look for path in storage.
+    if ($path = $this->storage->lookupPathSource($alias, $langcode)) {
+      $this->lookupMap[$langcode][$path] = $alias;
+      return $path;
+    }
+
+    // We can't record anything into $this->lookupMap because we didn't find any
+    // paths for this alias. Thus cache to $this->noPath.
+    $this->noPath[$langcode][$alias] = TRUE;
+
+    return $alias;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getAliasByPath($path, $langcode = NULL) {
+    if ($path[0] !== '/') {
+      throw new \InvalidArgumentException(sprintf('Source path %s has to start with a slash.', $path));
+    }
+    // If no language is explicitly specified we default to the current URL
+    // language. If we used a language different from the one conveyed by the
+    // requested URL, we might end up being unable to check if there is a path
+    // alias matching the URL path.
+    $langcode = $langcode ?: $this->languageManager->getCurrentLanguage(LanguageInterface::TYPE_URL)->getId();
+
+    // Check the path whitelist, if the top-level part before the first /
+    // is not in the list, then there is no need to do anything further,
+    // it is not in the database.
+    if ($path === '/' || !$this->whitelist->get(strtok(trim($path, '/'), '/'))) {
+      return $path;
+    }
+
+    // During the first call to this method per language, load the expected
+    // paths for the page from cache.
+    if (empty($this->langcodePreloaded[$langcode])) {
+      $this->langcodePreloaded[$langcode] = TRUE;
+      $this->lookupMap[$langcode] = [];
+
+      // Load the cached paths that should be used for preloading. This only
+      // happens if a cache key has been set.
+      if ($this->preloadedPathLookups === FALSE) {
+        $this->preloadedPathLookups = [];
+        if ($this->cacheKey) {
+          if ($cached = $this->cache->get($this->cacheKey)) {
+            $this->preloadedPathLookups = $cached->data;
+          }
+          else {
+            $this->cacheNeedsWriting = TRUE;
+          }
+        }
+      }
+
+      // Load paths from cache.
+      if (!empty($this->preloadedPathLookups[$langcode])) {
+        $this->lookupMap[$langcode] = $this->storage->preloadPathAlias($this->preloadedPathLookups[$langcode], $langcode);
+        // Keep a record of paths with no alias to avoid querying twice.
+        $this->noAlias[$langcode] = array_flip(array_diff_key($this->preloadedPathLookups[$langcode], array_keys($this->lookupMap[$langcode])));
+      }
+    }
+
+    // If we already know that there are no aliases for this path simply return.
+    if (!empty($this->noAlias[$langcode][$path])) {
+      return $path;
+    }
+
+    // If the alias has already been loaded, return it from static cache.
+    if (isset($this->lookupMap[$langcode][$path])) {
+      return $this->lookupMap[$langcode][$path];
+    }
+
+    // Try to load alias from storage.
+    if ($alias = $this->storage->lookupPathAlias($path, $langcode)) {
+      $this->lookupMap[$langcode][$path] = $alias;
+      return $alias;
+    }
+
+    // We can't record anything into $this->lookupMap because we didn't find any
+    // aliases for this path. Thus cache to $this->noAlias.
+    $this->noAlias[$langcode][$path] = TRUE;
+    return $path;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function cacheClear($source = NULL) {
+    if ($source) {
+      foreach (array_keys($this->lookupMap) as $lang) {
+        unset($this->lookupMap[$lang][$source]);
+      }
+    }
+    else {
+      $this->lookupMap = [];
+    }
+    $this->noPath = [];
+    $this->noAlias = [];
+    $this->langcodePreloaded = [];
+    $this->preloadedPathLookups = [];
+    $this->cache->delete($this->cacheKey);
+    $this->pathAliasWhitelistRebuild($source);
+  }
+
+  /**
+   * Rebuild the path alias white list.
+   *
+   * @param string $path
+   *   An optional path for which an alias is being inserted.
+   *
+   * @return
+   *   An array containing a white list of path aliases.
+   */
+  protected function pathAliasWhitelistRebuild($path = NULL) {
+    // When paths are inserted, only rebuild the whitelist if the path has a top
+    // level component which is not already in the whitelist.
+    if (!empty($path)) {
+      if ($this->whitelist->get(strtok($path, '/'))) {
+        return;
+      }
+    }
+    $this->whitelist->clear();
+  }
+
+  /**
+   * Wrapper method for REQUEST_TIME constant.
+   *
+   * @return int
+   */
+  protected function getRequestTime() {
+    return defined('REQUEST_TIME') ? REQUEST_TIME : (int) $_SERVER['REQUEST_TIME'];
+  }
+
+}