Version 1

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

diff --git a/web/core/lib/Drupal/Core/Cache/MemoryBackend.php b/web/core/lib/Drupal/Core/Cache/MemoryBackend.php
new file mode 100644 (file)
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--- /dev/null
+++ b/web/core/lib/Drupal/Core/Cache/MemoryBackend.php
@@ -0,0 +1,222 @@
+<?php
+
+namespace Drupal\Core\Cache;
+
+/**
+ * Defines a memory cache implementation.
+ *
+ * Stores cache items in memory using a PHP array.
+ *
+ * Should be used for unit tests and specialist use-cases only, does not
+ * store cached items between requests.
+ *
+ * The functions ::prepareItem()/::set() use unserialize()/serialize(). It
+ * behaves as an external cache backend to avoid changing the cached data by
+ * reference. In ::prepareItem(), the object is not modified by the call to
+ * unserialize() because we make a clone of it.
+ *
+ * @ingroup cache
+ */
+class MemoryBackend implements CacheBackendInterface, CacheTagsInvalidatorInterface {
+
+  /**
+   * Array to store cache objects.
+   */
+  protected $cache = [];
+
+  /**
+   * {@inheritdoc}
+   */
+  public function get($cid, $allow_invalid = FALSE) {
+    if (isset($this->cache[$cid])) {
+      return $this->prepareItem($this->cache[$cid], $allow_invalid);
+    }
+    else {
+      return FALSE;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getMultiple(&$cids, $allow_invalid = FALSE) {
+    $ret = [];
+
+    $items = array_intersect_key($this->cache, array_flip($cids));
+
+    foreach ($items as $item) {
+      $item = $this->prepareItem($item, $allow_invalid);
+      if ($item) {
+        $ret[$item->cid] = $item;
+      }
+    }
+
+    $cids = array_diff($cids, array_keys($ret));
+
+    return $ret;
+  }
+
+  /**
+   * Prepares a cached item.
+   *
+   * Checks that items are either permanent or did not expire, and returns data
+   * as appropriate.
+   *
+   * @param object $cache
+   *   An item loaded from cache_get() or cache_get_multiple().
+   * @param bool $allow_invalid
+   *   (optional) If TRUE, cache items may be returned even if they have expired
+   *   or been invalidated.
+   *
+   * @return mixed
+   *   The item with data as appropriate or FALSE if there is no
+   *   valid item to load.
+   */
+  protected function prepareItem($cache, $allow_invalid) {
+    if (!isset($cache->data)) {
+      return FALSE;
+    }
+    // The object passed into this function is the one stored in $this->cache.
+    // We must clone it as part of the preparation step so that the actual
+    // cache object is not affected by the unserialize() call or other
+    // manipulations of the returned object.
+
+    $prepared = clone $cache;
+    $prepared->data = unserialize($prepared->data);
+
+    // Check expire time.
+    $prepared->valid = $prepared->expire == Cache::PERMANENT || $prepared->expire >= $this->getRequestTime();
+
+    if (!$allow_invalid && !$prepared->valid) {
+      return FALSE;
+    }
+
+    return $prepared;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function set($cid, $data, $expire = Cache::PERMANENT, array $tags = []) {
+    assert('\Drupal\Component\Assertion\Inspector::assertAllStrings($tags)', 'Cache Tags must be strings.');
+    $tags = array_unique($tags);
+    // Sort the cache tags so that they are stored consistently in the database.
+    sort($tags);
+    $this->cache[$cid] = (object) [
+      'cid' => $cid,
+      'data' => serialize($data),
+      'created' => $this->getRequestTime(),
+      'expire' => $expire,
+      'tags' => $tags,
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setMultiple(array $items = []) {
+    foreach ($items as $cid => $item) {
+      $this->set($cid, $item['data'], isset($item['expire']) ? $item['expire'] : CacheBackendInterface::CACHE_PERMANENT, isset($item['tags']) ? $item['tags'] : []);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function delete($cid) {
+    unset($this->cache[$cid]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function deleteMultiple(array $cids) {
+    $this->cache = array_diff_key($this->cache, array_flip($cids));
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function deleteAll() {
+    $this->cache = [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function invalidate($cid) {
+    if (isset($this->cache[$cid])) {
+      $this->cache[$cid]->expire = $this->getRequestTime() - 1;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function invalidateMultiple(array $cids) {
+    foreach ($cids as $cid) {
+      if (isset($this->cache[$cid])) {
+        $this->cache[$cid]->expire = $this->getRequestTime() - 1;
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function invalidateTags(array $tags) {
+    foreach ($this->cache as $cid => $item) {
+      if (array_intersect($tags, $item->tags)) {
+        $this->cache[$cid]->expire = $this->getRequestTime() - 1;
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function invalidateAll() {
+    foreach ($this->cache as $cid => $item) {
+      $this->cache[$cid]->expire = $this->getRequestTime() - 1;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function garbageCollection() {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function removeBin() {
+    $this->cache = [];
+  }
+
+  /**
+   * Wrapper method for REQUEST_TIME constant.
+   *
+   * @return int
+   */
+  protected function getRequestTime() {
+    return defined('REQUEST_TIME') ? REQUEST_TIME : (int) $_SERVER['REQUEST_TIME'];
+  }
+
+  /**
+   * Prevents data stored in memory backends from being serialized.
+   */
+  public function __sleep() {
+    return [];
+  }
+
+  /**
+   * Reset statically cached variables.
+   *
+   * This is only used by tests.
+   */
+  public function reset() {
+    $this->cache = [];
+  }
+
+}