diff --git a/core/includes/cache-install.inc b/core/includes/cache-install.inc deleted file mode 100644 index ec46ae0..0000000 --- a/core/includes/cache-install.inc +++ /dev/null @@ -1,87 +0,0 @@ -expire(); } - -/** - * Defines an interface for cache implementations. - * - * All cache implementations have to implement this interface. - * DrupalDatabaseCache provides the default implementation, which can be - * consulted as an example. - * - * To make Drupal use your implementation for a certain cache bin, you have to - * set a variable with the name of the cache bin as its key and the name of - * your class as its value. For example, if your implementation of - * DrupalCacheInterface was called MyCustomCache, the following line would make - * Drupal use it for the 'cache_page' bin: - * @code - * variable_set('cache_class_cache_page', 'MyCustomCache'); - * @endcode - * - * Additionally, you can register your cache implementation to be used by - * default for all cache bins by setting the variable 'cache_default_class' to - * the name of your implementation of the DrupalCacheInterface, e.g. - * @code - * variable_set('cache_default_class', 'MyCustomCache'); - * @endcode - * - * To implement a completely custom cache bin, use the same variable format: - * @code - * variable_set('cache_class_custom_bin', 'MyCustomCache'); - * @endcode - * To access your custom cache bin, specify the name of the bin when storing - * or retrieving cached data: - * @code - * cache_set($cid, $data, 'custom_bin', $expire); - * cache_get($cid, 'custom_bin'); - * @endcode - * - * @see cache() - * @see DrupalDatabaseCache - */ -interface DrupalCacheInterface { - /** - * Constructs a new cache interface. - * - * @param $bin - * The cache bin for which the object is created. - */ - function __construct($bin); - - /** - * Returns 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. - * - * @param $cid - * The cache ID of the data to retrieve. - * - * @return - * The cache or FALSE on failure. - */ - function get($cid); - - /** - * 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); - - /** - * Stores data in the persistent cache. - * - * @param $cid - * The cache ID of the data to store. - * @param $data - * The data to store in the cache. Complex data types will be automatically - * serialized before insertion. - * Strings will be stored as plain text and not serialized. - * @param $expire - * One of the following values: - * - CACHE_PERMANENT: Indicates that the item should never be removed unless - * explicitly told to using cache_clear_all() with a cache ID. - * - CACHE_TEMPORARY: Indicates that the item should be removed at the next - * general cache wipe. - * - A Unix timestamp: Indicates that the item should be kept at least until - * the given time, after which it behaves like CACHE_TEMPORARY. - */ - function set($cid, $data, $expire = CACHE_PERMANENT); - - /** - * Deletes an item from the cache. - * - * @param $cid - * The cache ID to delete. - */ - function delete($cid); - - /** - * Deletes multiple items from the cache. - * - * @param $cids - * An array of $cids to delete. - */ - function deleteMultiple(Array $cids); - - /** - * Deletes items from the cache using a wildcard prefix. - * - * @param $prefix - * A wildcard prefix. - */ - function deletePrefix($prefix); - - /** - * Flushes all cache items in a bin. - */ - function flush(); - - /** - * Expires temporary items from the cache. - */ - function expire(); - - /** - * Performs garbage collection on a cache bin. - */ - function garbageCollection(); - - /** - * Checks if 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. - */ - function isEmpty(); -} - -/** - * Defines a stub cache implementation. - * - * The stub implementation is needed when database access is not yet available. - * Because Drupal's caching system never requires that cached data be present, - * these stub functions can short-circuit the process and sidestep the need for - * any persistent storage. Using this cache implementation during normal - * operations would have a negative impact on performance. - * - * This also can be used for testing purposes. - */ -class DrupalNullCache implements DrupalCacheInterface { - - /** - * Constructs a DrupalNullCache object. - */ - function __construct($bin) {} - - /** - * Implements DrupalCacheInterface::get(). - */ - function get($cid) { - return FALSE; - } - - /** - * Implements DrupalCacheInterface::getMultiple(). - */ - function getMultiple(&$cids) { - return array(); - } - - /** - * Implements DrupalCacheInterface::set(). - */ - function set($cid, $data, $expire = CACHE_PERMANENT) {} - - /** - * Implements DrupalCacheInterface::delete(). - */ - function delete($cid) {} - - /** - * Implements DrupalCacheInterface::deleteMultiple(). - */ - function deleteMultiple(array $cids) {} - - /** - * Implements DrupalCacheInterface::deletePrefix(). - */ - function deletePrefix($prefix) {} - - /** - * Implements DrupalCacheInterface::flush(). - */ - function flush() {} - - /** - * Implements DrupalCacheInterface::expire(). - */ - function expire() {} - - /** - * Implements DrupalCacheInterface::garbageCollection(). - */ - function garbageCollection() {} - - /** - * Implements DrupalCacheInterface::isEmpty(). - */ - function isEmpty() { - return TRUE; - } -} - -/** - * Defines a default cache implementation. - * - * This is Drupal's default cache implementation. It uses the database to store - * cached data. Each cache bin corresponds to a database table by the same name. - */ -class DrupalDatabaseCache implements DrupalCacheInterface { - protected $bin; - - /** - * Constructs a new DrupalDatabaseCache object. - */ - function __construct($bin) { - // All cache tables should be prefixed with 'cache_', except for the - // default 'cache' bin. - if ($bin != 'cache') { - $bin = 'cache_' . $bin; - } - $this->bin = $bin; - } - - /** - * Implements DrupalCacheInterface::get(). - */ - function get($cid) { - $cids = array($cid); - $cache = $this->getMultiple($cids); - return reset($cache); - } - - /** - * Implements DrupalCacheInterface::getMultiple(). - */ - function getMultiple(&$cids) { - try { - // Garbage collection necessary when enforcing a minimum cache lifetime. - $this->garbageCollection($this->bin); - - // When serving cached pages, the overhead of using db_select() was found - // to add around 30% overhead to the request. Since $this->bin is a - // variable, this means the call to db_query() here uses a concatenated - // string. This is highly discouraged under any other circumstances, and - // is used here only due to the performance overhead we would incur - // otherwise. When serving an uncached page, the overhead of using - // db_select() is a much smaller proportion of the request. - $result = db_query('SELECT cid, data, created, expire, serialized FROM {' . db_escape_table($this->bin) . '} WHERE cid IN (:cids)', array(':cids' => $cids)); - $cache = array(); - foreach ($result as $item) { - $item = $this->prepareItem($item); - if ($item) { - $cache[$item->cid] = $item; - } - } - $cids = array_diff($cids, array_keys($cache)); - return $cache; - } - catch (Exception $e) { - // If the database is never going to be available, cache requests should - // return FALSE in order to allow exception handling to occur. - return array(); - } - } - - /** - * Prepares a cached item. - * - * Checks that items are either permanent or did not expire, and unserializes - * data as appropriate. - * - * @param $cache - * An item loaded from cache_get() or cache_get_multiple(). - * - * @return - * The item with data unserialized as appropriate or FALSE if there is no - * valid item to load. - */ - protected function prepareItem($cache) { - global $user; - - if (!isset($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 > $cache->created) { - // This cache data is too old and thus not valid for us, ignore it. - return FALSE; - } - - if ($cache->serialized) { - $cache->data = unserialize($cache->data); - } - - return $cache; - } - - /** - * Implements DrupalCacheInterface::set(). - */ - function set($cid, $data, $expire = CACHE_PERMANENT) { - $fields = array( - 'serialized' => 0, - 'created' => REQUEST_TIME, - 'expire' => $expire, - ); - if (!is_string($data)) { - $fields['data'] = serialize($data); - $fields['serialized'] = 1; - } - else { - $fields['data'] = $data; - $fields['serialized'] = 0; - } - - try { - db_merge($this->bin) - ->key(array('cid' => $cid)) - ->fields($fields) - ->execute(); - } - catch (Exception $e) { - // The database may not be available, so we'll ignore these calls. - } - } - - /** - * Implements DrupalCacheInterface::delete(). - */ - function delete($cid) { - db_delete($this->bin) - ->condition('cid', $cid) - ->execute(); - } - - /** - * Implements DrupalCacheInterface::deleteMultiple(). - */ - function deleteMultiple(Array $cids) { - // Delete in chunks when a large array is passed. - do { - db_delete($this->bin) - ->condition('cid', array_splice($cids, 0, 1000), 'IN') - ->execute(); - } - while (count($cids)); - } - - /** - * Implements DrupalCacheInterface::deletePrefix(). - */ - function deletePrefix($prefix) { - db_delete($this->bin) - ->condition('cid', db_like($prefix) . '%', 'LIKE') - ->execute(); - } - - /** - * Implements DrupalCacheInterface::flush(). - */ - function flush() { - db_truncate($this->bin)->execute(); - } - - /** - * Implements DrupalCacheInterface::expire(). - */ - 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; - - $cache_flush = variable_get('cache_flush_' . $this->bin, 0); - if ($cache_flush == 0) { - // This is the first request to clear the cache; start a timer. - variable_set('cache_flush_' . $this->bin, REQUEST_TIME); - } - elseif (REQUEST_TIME > ($cache_flush + variable_get('cache_lifetime', 0))) { - // Clear the cache for everyone; cache_lifetime seconds have passed - // since the first request to clear the cache. - db_delete($this->bin) - ->condition('expire', CACHE_PERMANENT, '<>') - ->condition('expire', REQUEST_TIME, '<') - ->execute(); - variable_set('cache_flush_' . $this->bin, 0); - } - } - else { - // No minimum cache lifetime; flush all temporary cache entries now. - db_delete($this->bin) - ->condition('expire', CACHE_PERMANENT, '<>') - ->condition('expire', REQUEST_TIME, '<') - ->execute(); - } - } - - /** - * Implements DrupalCacheInterface::garbageCollection(). - */ - function garbageCollection() { - global $user; - - // 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. - variable_set('cache_flush_' . $this->bin, 0); - // Time to flush old cache data - db_delete($this->bin) - ->condition('expire', CACHE_PERMANENT, '<>') - ->condition('expire', $cache_flush, '<=') - ->execute(); - } - } - - /** - * Implements DrupalCacheInterface::isEmpty(). - */ - function isEmpty() { - $this->garbageCollection(); - $query = db_select($this->bin); - $query->addExpression('1'); - $result = $query->range(0, 1) - ->execute() - ->fetchField(); - return empty($result); - } -} diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc index 6bdbf4d..f9269ce 100644 --- a/core/includes/install.core.inc +++ b/core/includes/install.core.inc @@ -277,8 +277,7 @@ function install_begin_request(&$install_state) { // because any data put in the cache during the installer is inherently // suspect, due to the fact that Drupal is not fully set up yet. require_once DRUPAL_ROOT . '/core/includes/cache.inc'; - require_once DRUPAL_ROOT . '/core/includes/cache-install.inc'; - $conf['cache_default_class'] = 'DrupalFakeCache'; + $conf['cache_default_class'] = 'Drupal\\Cache\\InstallBackend'; // Prepare for themed output. We need to run this at the beginning of the // page request to avoid a different theme accidentally getting set. (We also diff --git a/core/includes/Drupal/Cache/BackendInterface.php b/core/includes/Drupal/Cache/BackendInterface.php new file mode 100644 index 0000000..ad9feac --- /dev/null +++ b/core/includes/Drupal/Cache/BackendInterface.php @@ -0,0 +1,172 @@ +bin = $bin; + } + + /** + * Implements DrupalCacheInterface::get(). + */ + function get($cid) { + $cids = array($cid); + $cache = $this->getMultiple($cids); + return reset($cache); + } + + /** + * Implements DrupalCacheInterface::getMultiple(). + */ + function getMultiple(&$cids) { + try { + // Garbage collection necessary when enforcing a minimum cache lifetime. + $this->garbageCollection($this->bin); + + // When serving cached pages, the overhead of using db_select() was found + // to add around 30% overhead to the request. Since $this->bin is a + // variable, this means the call to db_query() here uses a concatenated + // string. This is highly discouraged under any other circumstances, and + // is used here only due to the performance overhead we would incur + // otherwise. When serving an uncached page, the overhead of using + // db_select() is a much smaller proportion of the request. + $result = db_query('SELECT cid, data, created, expire, serialized FROM {' . db_escape_table($this->bin) . '} WHERE cid IN (:cids)', array(':cids' => $cids)); + $cache = array(); + foreach ($result as $item) { + $item = $this->prepareItem($item); + if ($item) { + $cache[$item->cid] = $item; + } + } + $cids = array_diff($cids, array_keys($cache)); + return $cache; + } + catch (\Exception $e) { + // If the database is never going to be available, cache requests should + // return FALSE in order to allow exception handling to occur. + return array(); + } + } + + /** + * Prepares a cached item. + * + * Checks that items are either permanent or did not expire, and unserializes + * data as appropriate. + * + * @param $cache + * An item loaded from cache_get() or cache_get_multiple(). + * + * @return + * The item with data unserialized as appropriate or FALSE if there is no + * valid item to load. + */ + protected function prepareItem($cache) { + global $user; + + if (!isset($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 > $cache->created) { + // This cache data is too old and thus not valid for us, ignore it. + return FALSE; + } + + if ($cache->serialized) { + $cache->data = unserialize($cache->data); + } + + return $cache; + } + + /** + * Implements DrupalCacheInterface::set(). + */ + function set($cid, $data, $expire = CACHE_PERMANENT) { + $fields = array( + 'serialized' => 0, + 'created' => REQUEST_TIME, + 'expire' => $expire, + ); + if (!is_string($data)) { + $fields['data'] = serialize($data); + $fields['serialized'] = 1; + } + else { + $fields['data'] = $data; + $fields['serialized'] = 0; + } + + try { + db_merge($this->bin) + ->key(array('cid' => $cid)) + ->fields($fields) + ->execute(); + } + catch (\Exception $e) { + // The database may not be available, so we'll ignore cache_set requests. + } + } + + /** + * Implements DrupalCacheInterface::delete(). + */ + function delete($cid) { + db_delete($this->bin) + ->condition('cid', $cid) + ->execute(); + } + + /** + * Implements DrupalCacheInterface::deleteMultiple(). + */ + function deleteMultiple(Array $cids) { + // Delete in chunks when a large array is passed. + do { + db_delete($this->bin) + ->condition('cid', array_splice($cids, 0, 1000), 'IN') + ->execute(); + } + while (count($cids)); + } + + /** + * Implements DrupalCacheInterface::deletePrefix(). + */ + function deletePrefix($prefix) { + db_delete($this->bin) + ->condition('cid', db_like($prefix) . '%', 'LIKE') + ->execute(); + } + + /** + * Implements DrupalCacheInterface::flush(). + */ + function flush() { + db_truncate($this->bin)->execute(); + } + + /** + * Implements DrupalCacheInterface::expire(). + */ + 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; + + $cache_flush = variable_get('cache_flush_' . $this->bin, 0); + if ($cache_flush == 0) { + // This is the first request to clear the cache, start a timer. + variable_set('cache_flush_' . $this->bin, REQUEST_TIME); + } + elseif (REQUEST_TIME > ($cache_flush + variable_get('cache_lifetime', 0))) { + // Clear the cache for everyone, cache_lifetime seconds have + // passed since the first request to clear the cache. + db_delete($this->bin) + ->condition('expire', CACHE_PERMANENT, '<>') + ->condition('expire', REQUEST_TIME, '<') + ->execute(); + variable_set('cache_flush_' . $this->bin, 0); + } + } + else { + // No minimum cache lifetime, flush all temporary cache entries now. + db_delete($this->bin) + ->condition('expire', CACHE_PERMANENT, '<>') + ->condition('expire', REQUEST_TIME, '<') + ->execute(); + } + } + + /** + * Implements DrupalCacheInterface::garbageCollection(). + */ + function garbageCollection() { + global $user; + + // 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. + variable_set('cache_flush_' . $this->bin, 0); + // Time to flush old cache data + db_delete($this->bin) + ->condition('expire', CACHE_PERMANENT, '<>') + ->condition('expire', $cache_flush, '<=') + ->execute(); + } + } + + /** + * Implements DrupalCacheInterface::clear(). + */ + function clear($cid = NULL, $wildcard = FALSE) { + global $user; + + if (empty($cid)) { + $this->expire(); + } + else { + if ($wildcard) { + if ($cid == '*') { + $this->flush(); + } + else { + $this->deletePrefix($cid); + } + } + elseif (is_array($cid)) { + $this->deleteMultiple($cid); + } + else { + $this->delete($cid); + } + } + } + + /** + * Implements DrupalCacheInterface::isEmpty(). + */ + function isEmpty() { + $this->garbageCollection(); + $query = db_select($this->bin); + $query->addExpression('1'); + $result = $query->range(0, 1) + ->execute() + ->fetchField(); + return empty($result); + } +} diff --git a/core/includes/Drupal/Cache/InstallBackend.php b/core/includes/Drupal/Cache/InstallBackend.php new file mode 100644 index 0000000..e4969e1 --- /dev/null +++ b/core/includes/Drupal/Cache/InstallBackend.php @@ -0,0 +1,89 @@ +