Issue #1015946 by pillarsdotnet, catch, bfroehle, Jej, jose.guevara, Damien...

Issue #1015946 by pillarsdotnet, catch, bfroehle, Jej, jose.guevara, Damien Tournoud: Fixed Eliminate $user->cache and {session}.cache in favor of $_SESSION['cache_expiration()'][].

core/includes/bootstrap.inc

@@ -1956,7 +1956,6 @@ function drupal_anonymous_user() {
   $user->hostname = ip_address();
   $user->roles = array();
   $user->roles[DRUPAL_ANONYMOUS_RID] = 'anonymous user';
-  $user->cache = 0;
   return $user;
 }
 

core/includes/session.inc

@@ -176,7 +176,6 @@ function _drupal_session_write($sid, $value) {
       // Either ssid or sid or both will be added from $key below.
       $fields = array(
         'uid' => $user->uid,
-        'cache' => isset($user->cache) ? $user->cache : 0,
         'hostname' => ip_address(),
         'session' => $value,
         'timestamp' => REQUEST_TIME,

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

@@ -95,18 +95,17 @@ protected function prepareItem($cache) {
     if (!isset($cache->data)) {
       return FALSE;
     }
-    // If enforcing a minimum cache lifetime, validate that the data is
-    // currently valid for this user before we return it by making sure the cache
-    // entry was created before the timestamp in the current session's cache
-    // timer. The cache variable is loaded into the $user object by
-    // _drupal_session_read() in session.inc. If the data is permanent or we're
-    // not enforcing a minimum cache lifetime always return the cached data.
+    // If the cached data is temporary and subject to a per-user minimum
+    // lifetime, compare the cache entry timestamp with the user session
+    // cache_expiration timestamp. If the cache entry is too old, ignore it.
     $config = config('system.performance');
-    if ($cache->expire != CACHE_PERMANENT && $config->get('cache_lifetime') && $user->cache > $cache->created) {
-      // This cache data is too old and thus not valid for us, ignore it.
+    if ($cache->expire != CACHE_PERMANENT && $config->get('cache_lifetime') && isset($_SESSION['cache_expiration'][$this->bin]) && $_SESSION['cache_expiration'][$this->bin] > $cache->created) {
+      // Ignore cache data that is too old and thus not valid for this user.
       return FALSE;
     }
 
+    // If the data is permanent or not subject to a minimum cache lifetime,
+    // unserialize and return the cached data.
     if ($cache->serialized) {
       $cache->data = unserialize($cache->data);
     }
@@ -186,11 +185,10 @@ function flush() {
    */
   function expire() {
     if (variable_get('cache_lifetime', 0)) {
-      // We store the time in the current user's $user->cache variable which
-      // will be saved into the sessions bin by _drupal_session_write(). We then
-      // simulate that the cache was flushed for this user by not returning
-      // cached data that was cached before the timestamp.
-      $GLOBALS['user']->cache = REQUEST_TIME;
+      // We store the time in the current user's session. We then simulate
+      // that the cache was flushed for this user by not returning cached
+      // data that was cached before the timestamp.
+      $_SESSION['cache_expiration'][$this->bin] = REQUEST_TIME;
 
       $cache_flush = variable_get('cache_flush_' . $this->bin, 0);
       if ($cache_flush == 0) {
@@ -220,12 +218,31 @@ function expire() {
    * Implements Drupal\Core\Cache\CacheBackendInterface::garbageCollection().
    */
   function garbageCollection() {
-    global $user;
+    $cache_lifetime = config('system.performance')->get('cache_lifetime');
 
+    // Clean-up the per-user cache expiration session data, so that the session
+    // handler can properly clean-up the session data for anonymous users.
+    if (isset($_SESSION['cache_expiration'])) {
+      $expire = REQUEST_TIME - $cache_lifetime;
+      foreach ($_SESSION['cache_expiration'] as $bin => $timestamp) {
+        if ($timestamp < $expire) {
+          unset($_SESSION['cache_expiration'][$bin]);
+        }
+      }
+      if (!$_SESSION['cache_expiration']) {
+        unset($_SESSION['cache_expiration']);
+      }
+    }
+
+    // Garbage collection of temporary items is only necessary when enforcing
+    // a minimum cache lifetime.
+    if (!$cache_lifetime) {
+      return;
+    }
     // When cache lifetime is in force, avoid running garbage collection too
     // often since this will remove temporary cache items indiscriminately.
     $cache_flush = variable_get('cache_flush_' . $this->bin, 0);
-    if ($cache_flush && ($cache_flush + variable_get('cache_lifetime', 0) <= REQUEST_TIME)) {
+    if ($cache_flush && ($cache_flush + $cache_lifetime <= REQUEST_TIME)) {
       // Reset the variable immediately to prevent a meltdown in heavy load situations.
       variable_set('cache_flush_' . $this->bin, 0);
       // Time to flush old cache data

core/modules/simpletest/tests/cache.test

@@ -336,6 +336,40 @@ class CacheClearCase extends CacheTestCase {
       $this->assertFalse($this->checkCacheExists($cid, $this->default_value, $bin), t('All cache entries removed from @bin.', array('@bin' => $bin)));
     }
   }
+
+  /**
+   * Test minimum cache lifetime.
+   */
+  function testMinimumCacheLifetime() {
+    // Set a minimum/maximum cache lifetime.
+    $this->setupLifetime(300);
+    // Login as a newly-created user.
+    $account = $this->drupalCreateUser(array());
+    $this->drupalLogin($account);
+
+    // Set two cache objects in different bins.
+    $data = $this->randomName(100);
+    cache()->set($data, $data, CACHE_TEMPORARY);
+    $cached = cache()->get($data);
+    $this->assertTrue(isset($cached->data) && $cached->data === $data, 'Cached item retrieved.');
+    cache('page')->set($data, $data, CACHE_TEMPORARY);
+
+    // Expire temporary items in the 'page' bin.
+    cache('page')->expire();
+
+    // Since the database cache uses REQUEST_TIME, set the $_SESSION variable
+    // manually to force it to the current time.
+    $_SESSION['cache_expiration']['cache_page'] = time();
+
+    // Items in the default cache bin should not be expired.
+    $cached = cache()->get($data);
+    $this->assertTrue(isset($cached->data) && $cached->data == $data, 'Cached item retrieved');
+
+    // Despite the minimum cache lifetime, the item in the 'page' bin should
+    // be invalidated for the current user.
+    $cached = cache('page')->get($data);
+    $this->assertFalse($cached, 'Cached item was invalidated');
+  }
 }
 
 /**

core/modules/system/system.install

@@ -1506,12 +1506,6 @@ function system_schema() {
         'not null' => TRUE,
         'default' => 0,
       ),
-      'cache' => array(
-        'description' => "The time of this user's last post. This is used when the site has specified a minimum_cache_lifetime. See Drupal\Core\Cache\CacheBackendInterface::get().",
-        'type' => 'int',
-        'not null' => TRUE,
-        'default' => 0,
-      ),
       'session' => array(
         'description' => 'The serialized contents of $_SESSION, an array of name/value pairs that persists across page requests by this session ID. Drupal loads $_SESSION from here at the start of each request and saves it at the end.',
         'type' => 'blob',
@@ -1760,6 +1754,13 @@ function system_update_8004() {
   }
 }
 
+ /**
+ * Remove the obsolete {session}.cache column.
+ */
+function system_update_8005() {
+  db_drop_field('session', 'cache');
+}
+
 /**
  * @} End of "defgroup updates-7.x-to-8.x"
  * The next series of updates should start at 9000.