Version 1

[yaffs-website] / web / core / lib / Drupal / Core / Cache / ChainedFastBackendFactory.php

diff --git a/web/core/lib/Drupal/Core/Cache/ChainedFastBackendFactory.php b/web/core/lib/Drupal/Core/Cache/ChainedFastBackendFactory.php
new file mode 100644 (file)
index 0000000..3169a35
--- /dev/null
+++ b/web/core/lib/Drupal/Core/Cache/ChainedFastBackendFactory.php
@@ -0,0 +1,91 @@
+<?php
+
+namespace Drupal\Core\Cache;
+use Drupal\Core\Site\Settings;
+use Symfony\Component\DependencyInjection\ContainerAwareTrait;
+
+/**
+ * Defines the chained fast cache backend factory.
+ *
+ * @see \Drupal\Core\Cache\ChainedFastBackend
+ */
+class ChainedFastBackendFactory implements CacheFactoryInterface {
+
+  use ContainerAwareTrait;
+
+  /**
+   * The service name of the consistent backend factory.
+   *
+   * @var string
+   */
+  protected $consistentServiceName;
+
+  /**
+   * The service name of the fast backend factory.
+   *
+   * @var string
+   */
+  protected $fastServiceName;
+
+  /**
+   * Constructs ChainedFastBackendFactory object.
+   *
+   * @param \Drupal\Core\Site\Settings|null $settings
+   *   (optional) The settings object.
+   * @param string|null $consistent_service_name
+   *   (optional) The service name of the consistent backend factory. Defaults
+   *   to:
+   *   - $settings->get('cache')['default'] (if specified)
+   *   - 'cache.backend.database' (if the above isn't specified)
+   * @param string|null $fast_service_name
+   *   (optional) The service name of the fast backend factory. Defaults to:
+   *   - 'cache.backend.apcu' (if the PHP process has APCu enabled)
+   *   - NULL (if the PHP process doesn't have APCu enabled)
+   */
+  public function __construct(Settings $settings = NULL, $consistent_service_name = NULL, $fast_service_name = NULL) {
+    // Default the consistent backend to the site's default backend.
+    if (!isset($consistent_service_name)) {
+      $cache_settings = isset($settings) ? $settings->get('cache') : [];
+      $consistent_service_name = isset($cache_settings['default']) ? $cache_settings['default'] : 'cache.backend.database';
+    }
+
+    // Default the fast backend to APCu if it's available.
+    if (!isset($fast_service_name) && function_exists('apcu_fetch')) {
+      $fast_service_name = 'cache.backend.apcu';
+    }
+
+    $this->consistentServiceName = $consistent_service_name;
+
+    // Do not use the fast chained backend during installation. In those cases,
+    // we expect many cache invalidations and writes, the fast chained cache
+    // backend performs badly in such a scenario.
+    if (!drupal_installation_attempted()) {
+      $this->fastServiceName = $fast_service_name;
+    }
+  }
+
+  /**
+   * Instantiates a chained, fast cache backend class for a given cache bin.
+   *
+   * @param string $bin
+   *   The cache bin for which a cache backend object should be returned.
+   *
+   * @return \Drupal\Core\Cache\CacheBackendInterface
+   *   The cache backend object associated with the specified bin.
+   */
+  public function get($bin) {
+    // Use the chained backend only if there is a fast backend available;
+    // otherwise, just return the consistent backend directly.
+    if (isset($this->fastServiceName)) {
+      return new ChainedFastBackend(
+        $this->container->get($this->consistentServiceName)->get($bin),
+        $this->container->get($this->fastServiceName)->get($bin),
+        $bin
+      );
+    }
+    else {
+      return $this->container->get($this->consistentServiceName)->get($bin);
+    }
+  }
+
+}