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Diffstat (limited to 'modules/gallery/libraries/drivers/Cache')
| -rw-r--r-- | modules/gallery/libraries/drivers/Cache/Database.php | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/modules/gallery/libraries/drivers/Cache/Database.php b/modules/gallery/libraries/drivers/Cache/Database.php new file mode 100644 index 00000000..e008f473 --- /dev/null +++ b/modules/gallery/libraries/drivers/Cache/Database.php @@ -0,0 +1,181 @@ +<?php defined('SYSPATH') OR die('No direct access allowed.'); +/** + * Gallery - a web based photo album viewer and editor + * Copyright (C) 2000-2009 Bharat Mediratta + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. + */ +/* + * Based on the Cache_Sqlite_Driver developed by the Kohana Team + */ +class Cache_Database_Driver implements Cache_Driver { + // Kohana database instance + protected $db; + + /** + * Tests that the storage location is a directory and is writable. + */ + public function __construct() { + // Open up an instance of the database + $this->db = Database::instance(); + + if (!$this->db->table_exists("caches")) { + throw new Kohana_Exception('cache.driver_error', "Cache table is not defined"); + } + Kohana::log('debug', 'Cache Database Driver Initialized'); + } + + /** + * Checks if a cache id is already set. + * + * @param string cache id + * @return boolean + */ + public function exists($id) { + $count = $this->db->count_records("caches", array('id' => $id, "expiration >=" => time())); + return $count > 0; + } + + /** + * Sets a cache item to the given data, tags, and lifetime. + * + * @param string cache id to set + * @param string data in the cache + * @param array cache tags + * @param integer lifetime + * @return bool + */ + public function set($id, $data, array $tags = NULL, $lifetime) { + if (!empty($tags)) { + // Escape the tags, adding brackets so the tag can be explicitly matched + $tags = '<' . implode('>,<', $tags) . '>'; + } + + // Cache Database driver expects unix timestamp + if ($lifetime !== 0) { + $lifetime += time(); + } + + $data = serialize($data); + if ($this->exists($id)) { + $status = $this->db->update("caches", + array("tags" => $tags, "expiration" => $lifetime, "cache" => $data), array("id" => $id)); + } else { + $status = $this->db->insert("caches", + array("id" => $id, "tags" => $tags, "expiration" => $lifetime, "cache" => $data)); + } + + return count($status) > 0; + } + + /** + * Finds an array of ids for a given tag. + * + * @param string tag name + * @return array of ids that match the tag + */ + public function find($tag) { + $db_result = $this->db->from("caches") + ->like("tags", "<$tag>") + ->get() + ->result(true); + + // An array will always be returned + $result = array(); + + if ($db_result->count() > 0) { + // Disable notices for unserializing + $ER = error_reporting(~E_NOTICE); + + foreach ($db_result as $row) { + // Add each cache to the array + $result[$row->id] = unserialize($row->cache); + } + + // Turn notices back on + error_reporting($ER); + } + + return $result; + } + + /** + * Fetches a cache item. This will delete the item if it is expired or if + * the hash does not match the stored hash. + * + * @param string cache id + * @return mixed|NULL + */ + public function get($id) { + $data = null; + $result = $this->db->getwhere("caches", array('id' => $id)); + + if (count($result) > 0) { + $cache = $result->current(); + // Make sure the expiration is valid and that the hash matches + if ($cache->expiration != 0 && $cache->expiration <= time()) { + // Cache is not valid, delete it now + $this->delete($cache->id); + } else { + // Disable notices for unserializing + $ER = error_reporting(~E_NOTICE); + + // Return the valid cache data + $data = unserialize($cache->cache); + + // Turn notices back on + error_reporting($ER); + } + } + + return $data; + } + + /** + * Deletes a cache item by id or tag + * + * @param string cache id or tag, or true for "all items" + * @param bool delete a tag + * @return bool + */ + public function delete($id, $tag = false) { + $this->db->from("caches"); + if ($id === true) { + $this->db->where(1); + // Delete all caches + } else if ($tag === true) { + $this->db->like("tags", "<$id>"); + } else { + $this->db->where("id", $id); + } + + $status = $this->db->delete(); + + return count($status) > 0; + } + + /** + * Deletes all cache files that are older than the current time. + */ + public function delete_expired() { + // Delete all expired caches + $status = $this->db->from("caches") + ->where(array("expiration !=" => 0, "expiration <=" => time())) + ->delete(); + + return count($status) > 0; + } + +} // End Cache Database Driver
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