Initial commit of Caching Driver.
diff --git a/system/libraries/Cache/drivers/Cache_file.php b/system/libraries/Cache/drivers/Cache_file.php
new file mode 100644
index 0000000..bedbfaf
--- /dev/null
+++ b/system/libraries/Cache/drivers/Cache_file.php
@@ -0,0 +1,196 @@
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 4.3.2 or newer
+ *
+ * @package CodeIgniter
+ * @author ExpressionEngine Dev Team
+ * @copyright Copyright (c) 2006 - 2010 EllisLab, Inc.
+ * @license http://codeigniter.com/user_guide/license.html
+ * @link http://codeigniter.com
+ * @since Version 2.0
+ * @filesource
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * CodeIgniter Memcached Caching Class
+ *
+ * @package CodeIgniter
+ * @subpackage Libraries
+ * @category Core
+ * @author ExpressionEngine Dev Team
+ * @link
+ */
+
+class Cache_file extends CI_Driver {
+
+ protected $_cache_path;
+
+ /**
+ * Constructor
+ */
+ public function __construct()
+ {
+ $CI =& get_instance();
+ $CI->load->helper('file');
+
+ $path = $CI->config->item('cache_path');
+
+ $this->_cache_path = ($path == '') ? BASEPATH.'cache/' : $path;
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Fetch from cache
+ *
+ * @param mixed unique key id
+ * @return mixed data on success/false on failure
+ */
+ public function get($id)
+ {
+ if ( ! file_exists($this->_cache_path.$id))
+ {
+ return FALSE;
+ }
+
+ $data = read_file($this->_cache_path.$id);
+ $data = unserialize($data);
+
+ if (time() > $data['time'] + $data['ttl'])
+ {
+ unlink($this->_cache_path.$id);
+ return FALSE;
+ }
+
+ return $data['data'];
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Save into cache
+ *
+ * @param string unique key
+ * @param mixed data to store
+ * @param int length of time (in seconds) the cache is valid
+ * - Default is 60 seconds
+ * @return boolean true on success/false on failure
+ */
+ public function save($id, $data, $ttl = 60)
+ {
+ $contents = array(
+ 'time' => time(),
+ 'ttl' => $ttl,
+ 'data' => $data
+ );
+
+ if (write_file($this->_cache_path.$id, serialize($contents)))
+ {
+ @chmod($this->_cache_path.$id, 0777);
+ return TRUE;
+ }
+
+ return FALSE;
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Delete from Cache
+ *
+ * @param mixed unique identifier of item in cache
+ * @return boolean true on success/false on failure
+ */
+ public function delete($id)
+ {
+ return unlink($this->_cache_path.$id);
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Clean the Cache
+ *
+ * @return boolean false on failure/true on success
+ */
+ public function clean()
+ {
+ return delete_files($this->_cache_path);
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Cache Info
+ *
+ * Not supported by file-based caching
+ *
+ * @param string user/filehits
+ * @return mixed FALSE
+ */
+ public function cache_info($type = NULL)
+ {
+ return get_dir_file_info($this->_cache_path);
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Get Cache Metadata
+ *
+ * @param mixed key to get cache metadata on
+ * @return mixed FALSE on failure, array on success.
+ */
+ public function get_metadata($id)
+ {
+ if ( ! file_exists($this->_cache_path.$id))
+ {
+ return FALSE;
+ }
+
+ $data = read_file($this->_cache_path.$id);
+ $data = unserialize($data);
+
+ if (is_array($data))
+ {
+ $data = $data['data'];
+ $mtime = filemtime($this->_cache_path.$id);
+
+ if ( ! isset($data['ttl']))
+ {
+ return FALSE;
+ }
+
+ return array(
+ 'expire' => $mtime + $data['ttl'],
+ 'mtime' => $mtime
+ );
+ }
+
+ return FALSE;
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Is supported
+ *
+ * In the file driver, check to see that the cache directory is indeed writable
+ *
+ * @return boolean
+ */
+ public function is_supported()
+ {
+ return is_really_writable($this->_cache_path);
+ }
+
+ // ------------------------------------------------------------------------
+}
+// End Class
+
+/* End of file Cache_file.php */
+/* Location: ./system/libraries/Cache/drivers/Cache_file.php */
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