/system/libraries/drivers/Cache/Sqlite.php
PHP | 228 lines | 119 code | 34 blank | 75 comment | 12 complexity | 13e0a5fe5edadccc1bdffd09692559cd MD5 | raw file
Possible License(s): LGPL-2.1
- <?php defined('SYSPATH') OR die('No direct access allowed.');
- /**
- * SQLite-based Cache driver.
- *
- * $Id: Sqlite.php 3917 2009-01-21 03:06:22Z zombor $
- *
- * @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('alert', '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('info', '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, $tags, $lifetime)
- {
- // Find the data hash
- $hash = sha1($data);
- // Escape the data
- $data = sqlite_escape_string($data);
- // Escape the tags
- $tags = sqlite_escape_string(implode(',', $tags));
- // Cache Sqlite driver expects unix timestamp
- if ($lifetime !== 0)
- {
- $lifetime += time();
- }
- $query = $this->exists($id)
- ? "UPDATE caches SET hash = '$hash', tags = '$tags', expiration = '$lifetime', cache = '$data' WHERE id = '$id'"
- : "INSERT INTO caches VALUES('$id', '$hash', '$tags', '$lifetime', '$data')";
- // Run the query
- $this->db->unbufferedQuery($query, SQLITE_BOTH, $error);
- empty($error) or self::log_error($error);
- return empty($error);
- }
- /**
- * 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)
- {
- $query = "SELECT id FROM caches WHERE tags LIKE '%{$tag}%'";
- $query = $this->db->query($query, SQLITE_BOTH, $error);
- empty($error) or self::log_error($error);
- if (empty($error) AND $query->numRows() > 0)
- {
- $array = array();
- while ($row = $query->fetchObject())
- {
- // Add each id to the array
- $array[] = $row->id;
- }
- return $array;
- }
- return FALSE;
- }
- /**
- * Fetches a cache item. This will delete the item if it is expired or if
- * the hash does not match the stored hash.
- *
- * @param string cache id
- * @return mixed|NULL
- */
- public function get($id)
- {
- $query = "SELECT id, hash, expiration, cache FROM caches WHERE id = '{$id}' LIMIT 0, 1";
- $query = $this->db->query($query, SQLITE_BOTH, $error);
- empty($error) or self::log_error($error);
- if (empty($error) AND $cache = $query->fetchObject())
- {
- // Make sure the expiration is valid and that the hash matches
- if (($cache->expiration != 0 AND $cache->expiration <= time()) OR $cache->hash !== sha1($cache->cache))
- {
- // Cache is not valid, delete it now
- $this->delete($cache->id);
- }
- else
- {
- // Return the valid cache data
- return $cache->cache;
- }
- }
- // No valid cache found
- return NULL;
- }
- /**
- * Deletes a cache item by id or tag
- *
- * @param string cache id or tag, or TRUE for "all items"
- * @param bool use tags
- * @return bool
- */
- public function delete($id, $tag = FALSE)
- {
- if ($id === TRUE)
- {
- // Delete all caches
- $where = '1';
- }
- elseif ($tag == FALSE)
- {
- // Delete by id
- $where = "id = '{$id}'";
- }
- else
- {
- // Delete by tag
- $where = "tags LIKE '%{$tag}%'";
- }
- $this->db->unbufferedQuery('DELETE FROM caches WHERE '.$where, SQLITE_BOTH, $error);
- empty($error) or self::log_error($error);
- return empty($error);
- }
- /**
- * 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