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<?php
// +----------------------------------------------------------------------+
// | PEAR :: Cache |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2003 The PHP Group |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.0 of the PHP license, |
// | that is bundled with this package in the file LICENSE, and is |
// | available at through the world-wide-web at |
// | http://www.php.net/license/2_02.txt. |
// | If you did not receive a copy of the PHP license and are unable to |
// | obtain it through the world-wide-web, please send a note to |
// | license@php.net so we can mail you a copy immediately. |
// +----------------------------------------------------------------------+
// | Authors: Ulf Wendel <ulf.wendel@phpdoc.de> |
// | Sebastian Bergmann <sb@sebastian-bergmann.de> |
// +----------------------------------------------------------------------+
//
// $Id: file.php 293864 2010-01-23 03:49:21Z clockwerx $
require_once 'Cache/Container.php';
/**
* Stores cache contents in a file.
*
* @author Ulf Wendel <ulf.wendel@phpdoc.de>
* @version $Id: file.php 293864 2010-01-23 03:49:21Z clockwerx $
*/
class Cache_Container_file extends Cache_Container
{
/**
* File locking
*
* With file container, it's possible, that you get corrupted
* data-entries under bad circumstances. The file locking must
* improve this problem but it's experimental stuff. So the
* default value is false. But it seems to give good results
*
* @var boolean
*/
var $fileLocking = false;
/**
* Directory where to put the cache files.
*
* @var string Make sure to add a trailing slash
*/
var $cache_dir = '';
/**
* Filename prefix for cache files.
*
* You can use the filename prefix to implement a "domain" based cache or just
* to give the files a more descriptive name. The word "domain" is borroed from
* a user authentification system. One user id (cached dataset with the ID x)
* may exists in different domains (different filename prefix). You might want
* to use this to have different cache values for a production, development and
* quality assurance system. If you want the production cache not to be influenced
* by the quality assurance activities, use different filename prefixes for them.
*
* I personally don't think that you'll never need this, but 640kb happend to be
* not enough, so... you know what I mean. If you find a useful application of the
* feature please update this inline doc.
*
* @var string
*/
var $filename_prefix = '';
/**
* List of cache entries, used within a gc run
*
* @var array
*/
var $entries;
/**
* Total number of bytes required by all cache entries, used within a gc run.
*
* @var int
*/
var $total_size = 0;
/**
* Max Line Length of userdata
*
* If set to 0, it will take the default
* ( 1024 in php 4.2, unlimited in php 4.3)
* see http://ch.php.net/manual/en/function.fgets.php
* for details
*
* @var int
*/
var $max_userdata_linelength = 257;
/**
* Creates the cache directory if neccessary
*
* @param array Config options: ["cache_dir" => ..., "filename_prefix" => ...]
*/
function Cache_Container_file($options = '')
{
if (is_array($options)) {
$this->setOptions($options, array_merge($this->allowed_options, array('cache_dir', 'filename_prefix', 'max_userdata_linelength')));
}
clearstatcache();
if ($this->cache_dir) {
// make relative paths absolute for use in deconstructor.
// it looks like the deconstructor has problems with relative paths
if (OS_UNIX && '/' != $this->cache_dir{0} )
$this->cache_dir = realpath( getcwd() . '/' . $this->cache_dir) . '/';
// check if a trailing slash is in cache_dir
if ($this->cache_dir{strlen($this->cache_dir)-1} != DIRECTORY_SEPARATOR)
$this->cache_dir .= '/';
if (!file_exists($this->cache_dir) || !is_dir($this->cache_dir))
mkdir($this->cache_dir, 0755);
}
$this->entries = array();
$this->group_dirs = array();
} // end func contructor
function fetch($id, $group)
{
$file = $this->getFilename($id, $group);
if (PEAR::isError($file)) {
return $file;
}
if (!file_exists($file)) {
return array(null, null, null);
}
// retrive the content
if (!($fh = @fopen($file, 'rb'))) {
return new Cache_Error("Can't access cache file '$file'. Check access rights and path.", __FILE__, __LINE__);
}
// File locking (shared lock)
if ($this->fileLocking) {
flock($fh, LOCK_SH);
}
// file format:
// 1st line: expiration date
// 2nd line: user data
// 3rd+ lines: cache data
$expire = trim(fgets($fh, 12));
if ($this->max_userdata_linelength == 0 ) {
$userdata = trim(fgets($fh));
} else {
$userdata = trim(fgets($fh, $this->max_userdata_linelength));
}
$buffer = '';
while (!feof($fh)) {
$buffer .= fread($fh, 8192);
}
$cachedata = $this->decode($buffer);
// Unlocking
if ($this->fileLocking) {
flock($fh, LOCK_UN);
}
fclose($fh);
// last usage date used by the gc - maxlifetime
// touch without second param produced stupid entries...
touch($file,time());
clearstatcache();
return array($expire, $cachedata, $userdata);
} // end func fetch
/**
* Stores a dataset.
*
* WARNING: If you supply userdata it must not contain any linebreaks,
* otherwise it will break the filestructure.
*/
function save($id, $cachedata, $expires, $group, $userdata)
{
$this->flushPreload($id, $group);
$file = $this->getFilename($id, $group);
if (!($fh = @fopen($file, 'wb'))) {
return new Cache_Error("Can't access '$file' to store cache data. Check access rights and path.", __FILE__, __LINE__);
}
// File locking (exclusive lock)
if ($this->fileLocking) {
flock($fh, LOCK_EX);
}
// file format:
// 1st line: expiration date
// 2nd line: user data
// 3rd+ lines: cache data
$expires = $this->getExpiresAbsolute($expires);
fwrite($fh, $expires . "\n");
fwrite($fh, $userdata . "\n");
fwrite($fh, $this->encode($cachedata));
// File unlocking
if ($this->fileLocking) {
flock($fh, LOCK_UN);
}
fclose($fh);
// I'm not sure if we need this
// i don't think we need this (chregu)
// touch($file);
return true;
} // end func save
function remove($id, $group)
{
$this->flushPreload($id, $group);
$file = $this->getFilename($id, $group);
if (PEAR::isError($file)) {
return $file;
}
if (file_exists($file)) {
$ok = unlink($file);
clearstatcache();
return $ok;
}
return false;
} // end func remove
function flush($group)
{
$this->flushPreload();
$dir = ($group) ? $this->cache_dir . $group . '/' : $this->cache_dir;
$num_removed = $this->deleteDir($dir);
unset($this->group_dirs[$group]);
clearstatcache();
return $num_removed;
} // end func flush
function idExists($id, $group)
{
return file_exists($this->getFilename($id, $group));
} // end func idExists
/**
* Deletes all expired files.
*
* Garbage collection for files is a rather "expensive", "long time"
* operation. All files in the cache directory have to be examined which
* means that they must be opened for reading, the expiration date has to be
* read from them and if neccessary they have to be unlinked (removed).
* If you have a user comment for a good default gc probability please add it to
* to the inline docs.
*
* @param integer Maximum lifetime in seconds of an no longer used/touched entry
* @throws Cache_Error
*/
function garbageCollection($maxlifetime)
{
$this->flushPreload();
clearstatcache();
$ok = $this->doGarbageCollection($maxlifetime, $this->cache_dir);
// check the space used by the cache entries
if ($this->total_size > $this->highwater) {
krsort($this->entries);
reset($this->entries);
while ($this->total_size > $this->lowwater && list($lastmod, $entry) = each($this->entries)) {
if (@unlink($entry['file'])) {
$this->total_size -= $entry['size'];
} else {
new CacheError("Can't delete {$entry['file']}. Check the permissions.");
}
}
}
$this->entries = array();
$this->total_size = 0;
return $ok;
} // end func garbageCollection
/**
* Does the recursive gc procedure, protected.
*
* @param integer Maximum lifetime in seconds of an no longer used/touched entry
* @param string directory to examine - don't sets this parameter, it's used for a
* recursive function call!
* @throws Cache_Error
*/
function doGarbageCollection($maxlifetime, $dir)
{
if (!is_writable($dir) || !is_readable($dir) || !($dh = opendir($dir))) {
return new Cache_Error("Can't remove directory '$dir'. Check permissions and path.", __FILE__, __LINE__);
}
while ($file = readdir($dh)) {
if ('.' == $file || '..' == $file)
continue;
$file = $dir . $file;
if (is_dir($file)) {
$this->doGarbageCollection($maxlifetime,$file . '/');
continue;
}
// skip trouble makers but inform the user
if (!($fh = @fopen($file, 'rb'))) {
new Cache_Error("Can't access cache file '$file', skipping it. Check permissions and path.", __FILE__, __LINE__);
continue;
}
$expire = fgets($fh, 11);
fclose($fh);
$lastused = filemtime($file);
$this->entries[$lastused] = array('file' => $file, 'size' => filesize($file));
$this->total_size += filesize($file);
// remove if expired
if (( ($expire && $expire <= time()) || ($lastused <= (time() - $maxlifetime)) ) && !unlink($file)) {
new Cache_Error("Can't unlink cache file '$file', skipping. Check permissions and path.", __FILE__, __LINE__);
}
}
closedir($dh);
// flush the disk state cache
clearstatcache();
} // end func doGarbageCollection
/**
* Returns the filename for the specified id.
*
* @param string dataset ID
* @param string cache group
* @return string full filename with the path
* @access public
*/
function getFilename($id, $group)
{
if (isset($this->group_dirs[$group])) {
return $this->group_dirs[$group] . $this->filename_prefix . $id;
}
$dir = $this->cache_dir . $group . '/';
if (is_writeable($this->cache_dir)) {
if (!file_exists($dir)) {
mkdir($dir, 0755, true);
clearstatcache();
}
} else {
return new Cache_Error("Can't make directory '$dir'. Check permissions and path.", __FILE__, __LINE__);
}
$this->group_dirs[$group] = $dir;
return $dir . $this->filename_prefix . $id;
} // end func getFilename
/**
* Deletes a directory and all files in it.
*
* @param string directory
* @return integer number of removed files
* @throws Cache_Error
*/
function deleteDir($dir)
{
if (!is_writable($dir) || !is_readable($dir) || !($dh = opendir($dir))) {
return new Cache_Error("Can't remove directory '$dir'. Check permissions and path.", __FILE__, __LINE__);
}
$num_removed = 0;
while (false !== $file = readdir($dh)) {
if ('.' == $file || '..' == $file)
continue;
$file = $dir . $file;
if (is_dir($file)) {
$file .= '/';
$num = $this->deleteDir($file . '/');
if (is_int($num))
$num_removed += $num;
} else {
if (unlink($file))
$num_removed++;
}
}
// according to php-manual the following is needed for windows installations.
closedir($dh);
unset( $dh);
if ($dir != $this->cache_dir) { //delete the sub-dir entries itself also, but not the cache-dir.
rmDir($dir);
$num_removed++;
}
return $num_removed;
} // end func deleteDir
} // end class file
?>
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