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<?php
/*
* $Horde: horde/lib/Cache/file.php,v 1.6.2.3 2003/01/03 12:48:41 jan Exp $
*
* Copyright 1999-2003 Anil Madhavapeddy <anil@recoil.org>
*
* See the enclosed file COPYING for license information (LGPL). If you
* did not receive this file, see http://www.fsf.org/copyleft/lgpl.html.
*/
/**
* The Cache:: class provides a common abstracted interface into the
* various caching backends. It also provides functions for checking
* in, retrieving, and flushing a cache.
*
* @author Anil Madhavapeddy <anil@recoil.org>
* @version $Revision: 1.6.2.3 $
* @since Horde 1.3
* @package horde.cache
*/
class Cache_file {
var $dir;
var $prefix = 'cache_';
/**
* Construct a new Cache_file object.
* @param array $params Parameters to determine where to cache
*/
function Cache_file($params = array())
{
if (!empty($params['dir']) && @is_dir($params['dir'])) {
$this->dir = $params['dir'];
} else {
$this->dir = Horde::getTempDir();
}
if (isset($params['prefix'])) {
$this->prefix = $params['prefix'];
}
}
/**
* Attempts to store an object in the cache.
*
* @param string $oid Object ID used as the caching key.
* @param mixed $data Data to store in the cache.
* @return boolean True on success, false on failure.
*/
function store($oid, &$data)
{
$filename = $this->oidToFile($oid);
$tmp_file = Horde::getTempFile('HordeCache', true, $this->dir);
if ($fd = fopen($tmp_file, 'w')) {
if (fwrite( $fd, $data ) < strlen($data)) {
fclose($fd);
return false;
} else {
fclose($fd);
rename($tmp_file, $filename);
}
}
}
/**
* Map an object ID to a unique filename.
* @param string $oid Object ID
* @return string Fully qualified filename.
*/
function oidToFile($oid)
{
return $this->dir . DIRECTORY_SEPARATOR . $this->prefix . md5($oid);
}
/**
* Attempts to retrieve a cached object from the filesystem.
*
* @param string $oid Object ID to query.
* @param int $type Expiration heuristic.
* CACHE_IMS: Expire if supplied value is greater than cached time
* @param int $val Value to supply for the expiration heuristic.
* @return mixed Cached data, or false if none was found.
*/
function query($oid, $type = CACHE_IMS, $val = 0)
{
$filename = $this->oidToFile($oid);
/* An object exists in the cache */
if (file_exists($filename)) {
$lastmod = filemtime($filename);
switch ($type) {
/* If the object has been created after the supplied
* value, object is valid */
case CACHE_IMS:
if ($val > $lastmod) {
@unlink($filename);
}
break;
/* Invalid cache query specified; unlink the object
* to be safe */
default:
@unlink($filename);
break;
}
/* This will fail if the object no longer exists */
if ($fd = @fopen($filename, 'r')) {
return fread($fd, filesize($filename));
}
}
/* Nothing cached, return failure */
return false;
}
}
?>
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