diff options
Diffstat (limited to 'system/libraries/drivers/Cache/Sqlite.php')
| -rw-r--r-- | system/libraries/drivers/Cache/Sqlite.php | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/system/libraries/drivers/Cache/Sqlite.php b/system/libraries/drivers/Cache/Sqlite.php new file mode 100644 index 00000000..9458d851 --- /dev/null +++ b/system/libraries/drivers/Cache/Sqlite.php @@ -0,0 +1,257 @@ +<?php defined('SYSPATH') OR die('No direct access allowed.'); +/** + * SQLite-based Cache driver. + * + * $Id: Sqlite.php 4046 2009-03-05 19:23:29Z Shadowhand $ + * + * @package Cache + * @author Kohana Team + * @copyright (c) 2007-2008 Kohana Team + * @license http://kohanaphp.com/license.html + */ +class Cache_Sqlite_Driver implements Cache_Driver { + + // SQLite database instance + protected $db; + + // Database error messages + protected $error; + + /** + * Logs an SQLite error. + */ + protected static function log_error($code) + { + // Log an error + Kohana::log('error', 'Cache: SQLite error: '.sqlite_error_string($error)); + } + + /** + * Tests that the storage location is a directory and is writable. + */ + public function __construct($filename) + { + // Get the directory name + $directory = str_replace('\\', '/', realpath(pathinfo($filename, PATHINFO_DIRNAME))).'/'; + + // Set the filename from the real directory path + $filename = $directory.basename($filename); + + // Make sure the cache directory is writable + if ( ! is_dir($directory) OR ! is_writable($directory)) + throw new Kohana_Exception('cache.unwritable', $directory); + + // Make sure the cache database is writable + if (is_file($filename) AND ! is_writable($filename)) + throw new Kohana_Exception('cache.unwritable', $filename); + + // Open up an instance of the database + $this->db = new SQLiteDatabase($filename, '0666', $error); + + // Throw an exception if there's an error + if ( ! empty($error)) + throw new Kohana_Exception('cache.driver_error', sqlite_error_string($error)); + + $query = "SELECT name FROM sqlite_master WHERE type = 'table' AND name = 'caches'"; + $tables = $this->db->query($query, SQLITE_BOTH, $error); + + // Throw an exception if there's an error + if ( ! empty($error)) + throw new Kohana_Exception('cache.driver_error', sqlite_error_string($error)); + + if ($tables->numRows() == 0) + { + Kohana::log('error', 'Cache: Initializing new SQLite cache database'); + + // Issue a CREATE TABLE command + $this->db->unbufferedQuery(Kohana::config('cache_sqlite.schema')); + } + } + + /** + * Checks if a cache id is already set. + * + * @param string cache id + * @return boolean + */ + public function exists($id) + { + // Find the id that matches + $query = "SELECT id FROM caches WHERE id = '$id'"; + + return ($this->db->query($query)->numRows() > 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) + { + // Serialize and escape the data + $data = sqlite_escape_string(serialize($data)); + + if ( ! empty($tags)) + { + // Escape the tags, adding brackets so the tag can be explicitly matched + $tags = sqlite_escape_string('<'.implode('>,<', $tags).'>'); + } + + // Cache Sqlite driver expects unix timestamp + if ($lifetime !== 0) + { + $lifetime += time(); + } + + $query = $this->exists($id) + ? "UPDATE caches SET tags = '$tags', expiration = '$lifetime', cache = '$data' WHERE id = '$id'" + : "INSERT INTO caches VALUES('$id', '$tags', '$lifetime', '$data')"; + + // Run the query + $this->db->unbufferedQuery($query, SQLITE_BOTH, $error); + + if ( ! empty($error)) + { + self::log_error($error); + return FALSE; + } + else + { + return TRUE; + } + } + + /** + * Finds an array of ids for a given tag. + * + * @param string tag name + * @return array of ids that match the tag + */ + public function find($tag) + { + $query = "SELECT id,cache FROM caches WHERE tags LIKE '%<{$tag}>%'"; + $query = $this->db->query($query, SQLITE_BOTH, $error); + + // An array will always be returned + $result = array(); + + if ( ! empty($error)) + { + self::log_error($error); + } + elseif ($query->numRows() > 0) + { + // Disable notices for unserializing + $ER = error_reporting(~E_NOTICE); + + while ($row = $query->fetchObject()) + { + // 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) + { + $query = "SELECT id, expiration, cache FROM caches WHERE id = '$id' LIMIT 0, 1"; + $query = $this->db->query($query, SQLITE_BOTH, $error); + + if ( ! empty($error)) + { + self::log_error($error); + } + elseif ($cache = $query->fetchObject()) + { + // Make sure the expiration is valid and that the hash matches + if ($cache->expiration != 0 AND $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 = $cache->cache; + + // Turn notices back on + error_reporting($ER); + } + } + + // No valid cache found + return NULL; + } + + /** + * 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, $tag = FALSE) + { + if ($id === TRUE) + { + // Delete all caches + $where = '1'; + } + elseif ($tag === TRUE) + { + // Delete by tag + $where = "tags LIKE '%<{$id}>%'"; + } + else + { + // Delete by id + $where = "id = '$id'"; + } + + $this->db->unbufferedQuery('DELETE FROM caches WHERE '.$where, SQLITE_BOTH, $error); + + if ( ! empty($error)) + { + self::log_error($error); + return FALSE; + } + else + { + return TRUE; + } + } + + /** + * Deletes all cache files that are older than the current time. + */ + public function delete_expired() + { + // Delete all expired caches + $query = 'DELETE FROM caches WHERE expiration != 0 AND expiration <= '.time(); + + $this->db->unbufferedQuery($query); + + return TRUE; + } + +} // End Cache SQLite Driver
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