From 015a9fba7a82e2fb8393941f0cc838ec126d1675 Mon Sep 17 00:00:00 2001 From: Bob Vincent Date: Sun, 2 Oct 2011 03:54:13 -0400 Subject: [PATCH] Issue #1015946: Fix per-user cache expiration. --- includes/bootstrap.inc | 1 - includes/cache.inc | 101 ++++++++++++++++++++++++++--------------- includes/session.inc | 1 - modules/system/system.install | 13 +++--- 4 files changed, 72 insertions(+), 44 deletions(-) diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc index 545beba21638014f886713bd07f04d4ffcb55165..66bef65e37c14ad63529d55170a264c83cf6dea8 100644 --- a/includes/bootstrap.inc +++ b/includes/bootstrap.inc @@ -2012,7 +2012,6 @@ function drupal_anonymous_user() { $user->hostname = ip_address(); $user->roles = array(); $user->roles[DRUPAL_ANONYMOUS_RID] = 'anonymous user'; - $user->cache = 0; return $user; } diff --git a/includes/cache.inc b/includes/cache.inc index 8666874ac6250efd71ec4ab873e6f0b39ada09b0..152f8c3f5a0a77d02de0c0d05f3f52fdc2450627 100644 --- a/includes/cache.inc +++ b/includes/cache.inc @@ -1,7 +1,7 @@ isEmpty(); @@ -227,13 +230,16 @@ interface DrupalCacheInterface { * * @param $bin * The cache bin for which the object is created. + * + * @return + * The newly-created DrupalCacheInterface object. */ function __construct($bin); /** - * Return data from the persistent cache. Data may be stored as either plain - * text or as serialized data. cache_get will automatically return - * unserialized objects and arrays. + * Returns data from the persistent cache. Data may be stored as either plain + * text or as serialized data. The cache_get() function will automatically + * return unserialized objects and arrays. * * @param $cid * The cache ID of the data to retrieve. @@ -243,19 +249,20 @@ interface DrupalCacheInterface { function get($cid); /** - * Return data from the persistent cache when given an array of cache IDs. + * Returns data from the persistent cache when given an array of cache IDs. * * @param $cids * An array of cache IDs for the data to retrieve. This is passed by * reference, and will have the IDs successfully returned from cache * removed. + * * @return * An array of the items successfully returned from cache indexed by cid. */ function getMultiple(&$cids); /** - * Store data in the persistent cache. + * Stores data in the persistent cache. * * @param $cid * The cache ID of the data to store. @@ -276,8 +283,10 @@ interface DrupalCacheInterface { /** - * Expire data from the cache. If called without arguments, expirable - * entries will be cleared from the cache_page and cache_block bins. + * Expires data from the cache. + * + * If called without arguments, expirable entries will be cleared from the + * cache_page and cache_block bins. * * @param $cid * If set, the cache ID to delete. Otherwise, all cache entries that can @@ -290,13 +299,13 @@ interface DrupalCacheInterface { function clear($cid = NULL, $wildcard = FALSE); /** - * Check if a cache bin is empty. + * Checks whether a cache bin is empty. * * A cache bin is considered empty if it does not contain any valid data for * any cache ID. * * @return - * TRUE if the cache bin specified is empty. + * TRUE if the cache bin specified is empty; FALSE otherwise. */ function isEmpty(); } @@ -351,18 +360,40 @@ class DrupalDatabaseCache implements DrupalCacheInterface { } /** - * Garbage collection for get() and getMultiple(). + * Performs garbage collection for get() and getMultiple(). * * @param $bin * The bin being requested. */ protected function garbageCollection() { - global $user; + $cache_lifetime = variable_get('cache_lifetime', 0); - // Garbage collection necessary when enforcing a minimum cache lifetime. + // Clean-up the per-user cache expiration session data, so that the session + // handler can properly clean-up the session data for anonymous users. + if (isset($_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. + $cache_lifetime = variable_get('cache_lifetime', 0); + if (!$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)) { - // Reset the variable immediately to prevent a meltdown in heavy load situations. + // Reset the variable immediately to prevent a meltdown in heavy load + // situations. variable_set('cache_flush_' . $this->bin, 0); // Time to flush old cache data db_delete($this->bin) @@ -373,13 +404,14 @@ class DrupalDatabaseCache implements DrupalCacheInterface { } /** - * Prepare a cached item. + * Prepares a cached item. * - * Checks that items are either permanent or did not expire, and unserializes - * data as appropriate. + * Checks whether items are either permanent or did not expire, and + * unserializes data as appropriate. * * @param $cache * An item loaded from cache_get() or cache_get_multiple(). + * * @return * The item with data unserialized as appropriate or FALSE if there is no * valid item to load. @@ -390,17 +422,15 @@ class DrupalDatabaseCache implements DrupalCacheInterface { if (!isset($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 $user object by _drupal_session_read() - // in session.inc. If the data is permanent or we're not enforcing a minimum - // cache lifetime always return the cached data. - if ($cache->expire != CACHE_PERMANENT && variable_get('cache_lifetime', 0) && $user->cache > $cache->created) { - // This cache data is too old and thus not valid for us, ignore it. + // If the cached data is temporary and subject to a per-user minimum + // lifetime, compare the cache entry timestamp with the user session + // cache_expiration timestamp. If the cache entry is too old, ignore it. + if ($cache->expire != CACHE_PERMANENT && variable_get('cache_lifetime', 0) && isset($_SESSION['cache_expiration'][$this->bin]) && $_SESSION['cache_expiration'][$this->bin] > $cache->created) { + // This cached data is too old; ignore it. return FALSE; } - + // If the data is permanent or not subject to a minimum cache lifetime, + // unserialize and return the cached data. if ($cache->serialized) { $cache->data = unserialize($cache->data); } @@ -439,11 +469,10 @@ class DrupalDatabaseCache implements DrupalCacheInterface { if (empty($cid)) { 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. - $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) { diff --git a/includes/session.inc b/includes/session.inc index fd04de8753b45e8c83cc0acd43a1fc013735cbf2..6af4643d695f408da4f3569e933c7cee8b48942f 100644 --- a/includes/session.inc +++ b/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, diff --git a/modules/system/system.install b/modules/system/system.install index 219f067d12ca98c2c93ed9a9171b6eb4eef9009c..29330fee4d0192bdbc2119df0a9f3e76a82b287f 100644 --- a/modules/system/system.install +++ b/modules/system/system.install @@ -1479,12 +1479,6 @@ 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 cache_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', @@ -2974,6 +2968,13 @@ function system_update_7071() { } /** + * Remove the obsolete {session}.cache column. + */ +function system_update_7072() { + db_drop_field('session', 'cache'); +} + +/** * @} End of "defgroup updates-6.x-to-7.x" * The next series of updates should start at 8000. */ -- 1.7.5.4