Issue #2386161 by Berdir, Wim Leers, beejeebus, olli: ChainedFastBackend...

Issue #2386161 by Berdir, Wim Leers, beejeebus, olli: ChainedFastBackend doesn't set 'expires' and 'tags' when writing to fastBackend

core/lib/Drupal/Core/Cache/ChainedFastBackend.php

@@ -160,7 +160,7 @@ public function getMultiple(&$cids, $allow_invalid = FALSE) {
     if ($cids) {
       foreach ($this->consistentBackend->getMultiple($cids, $allow_invalid) as $item) {
         $cache[$item->cid] = $item;
-        $this->fastBackend->set($item->cid, $item->data);
+        $this->fastBackend->set($item->cid, $item->data, $item->expire, $item->tags);
       }
     }
 
@@ -171,8 +171,8 @@ public function getMultiple(&$cids, $allow_invalid = FALSE) {
    * {@inheritdoc}
    */
   public function set($cid, $data, $expire = Cache::PERMANENT, array $tags = array()) {
-    $this->markAsOutdated();
     $this->consistentBackend->set($cid, $data, $expire, $tags);
+    $this->markAsOutdated();
     $this->fastBackend->set($cid, $data, $expire, $tags);
   }
 
@@ -180,8 +180,8 @@ public function set($cid, $data, $expire = Cache::PERMANENT, array $tags = array
    * {@inheritdoc}
    */
   public function setMultiple(array $items) {
-    $this->markAsOutdated();
     $this->consistentBackend->setMultiple($items);
+    $this->markAsOutdated();
     $this->fastBackend->setMultiple($items);
   }
 
@@ -189,16 +189,16 @@ public function setMultiple(array $items) {
    * {@inheritdoc}
    */
   public function delete($cid) {
-    $this->markAsOutdated();
     $this->consistentBackend->deleteMultiple(array($cid));
+    $this->markAsOutdated();
   }
 
   /**
    * {@inheritdoc}
    */
   public function deleteMultiple(array $cids) {
-    $this->markAsOutdated();
     $this->consistentBackend->deleteMultiple($cids);
+    $this->markAsOutdated();
   }
 
   /**
@@ -213,8 +213,8 @@ public function deleteTags(array $tags) {
    * {@inheritdoc}
    */
   public function deleteAll() {
-    $this->markAsOutdated();
     $this->consistentBackend->deleteAll();
+    $this->markAsOutdated();
   }
 
   /**
@@ -228,24 +228,24 @@ public function invalidate($cid) {
    * {@inheritdoc}
    */
   public function invalidateMultiple(array $cids) {
-    $this->markAsOutdated();
     $this->consistentBackend->invalidateMultiple($cids);
+    $this->markAsOutdated();
   }
 
   /**
    * {@inheritdoc}
    */
   public function invalidateTags(array $tags) {
-    $this->markAsOutdated();
     $this->consistentBackend->invalidateTags($tags);
+    $this->markAsOutdated();
   }
 
   /**
    * {@inheritdoc}
    */
   public function invalidateAll() {
-    $this->markAsOutdated();
     $this->consistentBackend->invalidateAll();
+    $this->markAsOutdated();
   }
 
   /**
@@ -289,7 +289,11 @@ protected function markAsOutdated() {
     // Clocks on a single server can drift. Multiple servers may have slightly
     // differing opinions about the current time. Given that, do not assume
     // 'now' on this server is always later than our stored timestamp.
-    $now = microtime(TRUE);
+    // Also add 1 millisecond, to ensure that caches written earlier in the same
+    // millisecond are invalidated. It is possible that caches will be later in
+    // the same millisecond and are then incorrectly invalidated, but that only
+    // costs one additional roundtrip to the persistent cache.
+    $now = round(microtime(TRUE) + .001, 3);
     if ($now > $this->getLastWriteTimestamp()) {
       $this->lastWriteTimestamp = $now;
       $this->consistentBackend->set(self::LAST_WRITE_TIMESTAMP_PREFIX . $this->bin, $this->lastWriteTimestamp);

core/modules/system/src/Tests/Cache/BackendChainUnitTest.php

@@ -28,4 +28,5 @@ protected function createCacheBackend($bin) {
 
     return $chain;
   }
+
 }

core/modules/system/src/Tests/Cache/ChainedFastBackendUnitTest.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\system\Tests\Cache\ChainedFastBackendUnitTest.
+ */
+
+namespace Drupal\system\Tests\Cache;
+
+use Drupal\Core\Cache\ChainedFastBackend;
+use Drupal\Core\Cache\DatabaseBackend;
+use Drupal\Core\Cache\PhpBackend;
+
+/**
+ * Unit test of the fast chained backend using the generic cache unit test base.
+ *
+ * @group Cache
+ */
+class ChainedFastBackendUnitTest extends GenericCacheBackendUnitTestBase {
+
+  /**
+   * Creates a new instance of ChainedFastBackend.
+   *
+   * @return \Drupal\Core\Cache\ChainedFastBackend
+   *   A new ChainedFastBackend object.
+   */
+  protected function createCacheBackend($bin) {
+    $consistent_backend = new DatabaseBackend($this->container->get('database'), $bin);
+    $fast_backend = new PhpBackend($bin);
+    return new ChainedFastBackend($consistent_backend, $fast_backend, $bin);
+  }
+
+}

core/tests/Drupal/Tests/Core/Cache/ChainedFastBackendTest.php

@@ -75,6 +75,8 @@ public function testFallThroughToConsistentCache() {
       'cid' => 'foo',
       'data' => 'baz',
       'created' => time(),
+      'expire' => time() + 3600,
+      'tags' => ['tag'],
     );
 
     $consistent_cache = $this->getMock('Drupal\Core\Cache\CacheBackendInterface');
@@ -101,7 +103,7 @@ public function testFallThroughToConsistentCache() {
     // We should get a call to set the cache item on the fast backend.
     $fast_cache->expects($this->once())
       ->method('set')
-      ->with($cache_item->cid, $cache_item->data);
+      ->with($cache_item->cid, $cache_item->data, $cache_item->expire, $cache_item->tags);
 
     $chained_fast_backend = new ChainedFastBackend(
       $consistent_cache,