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<?php
/**
*
* @package acm
* @version $Id$
* @copyright (c) 2005, 2009 phpBB Group
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
*
*/
/**
* @ignore
*/
if (!defined('IN_PHPBB'))
{
exit;
}
/**
* ACM File Based Caching
* @package acm
*/
class acm
{
var $vars = array();
var $var_expires = array();
var $is_modified = false;
var $sql_rowset = array();
var $sql_row_pointer = array();
var $cache_dir = '';
/**
* Set cache path
*/
function acm()
{
global $phpbb_root_path;
$this->cache_dir = $phpbb_root_path . 'cache/';
}
/**
* Load global cache
*/
function load()
{
return $this->_read('data_global');
}
/**
* Unload cache object
*/
function unload()
{
$this->save();
unset($this->vars);
unset($this->var_expires);
unset($this->sql_rowset);
unset($this->sql_row_pointer);
$this->vars = array();
$this->var_expires = array();
$this->sql_rowset = array();
$this->sql_row_pointer = array();
}
/**
* Save modified objects
*/
function save()
{
if (!$this->is_modified)
{
return;
}
global $phpEx;
if (!$this->_write('data_global'))
{
// Now, this occurred how often? ... phew, just tell the user then...
if (!@is_writable($this->cache_dir))
{
// We need to use die() here, because else we may encounter an infinite loop (the message handler calls $cache->unload())
die($this->cache_dir . ' is NOT writable.');
exit;
}
die('Not able to open ' . $this->cache_dir . 'data_global.' . $phpEx);
exit;
}
$this->is_modified = false;
}
/**
* Tidy cache
*/
function tidy()
{
global $phpEx;
$dir = @opendir($this->cache_dir);
if (!$dir)
{
return;
}
$time = time();
while (($entry = readdir($dir)) !== false)
{
if (!preg_match('/^(sql_|data_(?!global))/', $entry))
{
continue;
}
if (!($handle = @fopen($this->cache_dir . $entry, 'rb')))
{
continue;
}
// Skip the PHP header
fgets($handle);
// Skip expiration
$expires = (int) fgets($handle);
fclose($handle);
if ($time >= $expires)
{
$this->remove_file($this->cache_dir . $entry);
}
}
closedir($dir);
if (file_exists($this->cache_dir . 'data_global.' . $phpEx))
{
if (!sizeof($this->vars))
{
$this->load();
}
foreach ($this->var_expires as $var_name => $expires)
{
if ($time >= $expires)
{
$this->destroy($var_name);
}
}
}
set_config('cache_last_gc', time(), true);
}
/**
* Get saved cache object
*/
function get($var_name)
{
if ($var_name[0] == '_')
{
global $phpEx;
if (!$this->_exists($var_name))
{
return false;
}
return $this->_read('data' . $var_name);
}
else
{
return ($this->_exists($var_name)) ? $this->vars[$var_name] : false;
}
}
/**
* Put data into cache
*/
function put($var_name, $var, $ttl = 31536000)
{
if ($var_name[0] == '_')
{
$this->_write('data' . $var_name, $var, time() + $ttl);
}
else
{
$this->vars[$var_name] = $var;
$this->var_expires[$var_name] = time() + $ttl;
$this->is_modified = true;
}
}
/**
* Purge cache data
*/
function purge()
{
// Purge all phpbb cache files
$dir = @opendir($this->cache_dir);
if (!$dir)
{
return;
}
while (($entry = readdir($dir)) !== false)
{
if (strpos($entry, 'sql_') !== 0 && strpos($entry, 'data_') !== 0 && strpos($entry, 'ctpl_') !== 0 && strpos($entry, 'tpl_') !== 0)
{
continue;
}
$this->remove_file($this->cache_dir . $entry);
}
closedir($dir);
unset($this->vars);
unset($this->var_expires);
unset($this->sql_rowset);
unset($this->sql_row_pointer);
$this->vars = array();
$this->var_expires = array();
$this->sql_rowset = array();
$this->sql_row_pointer = array();
$this->is_modified = false;
}
/**
* Destroy cache data
*/
function destroy($var_name, $table = '')
{
global $phpEx;
if ($var_name == 'sql' && !empty($table))
{
if (!is_array($table))
{
$table = array($table);
}
$dir = @opendir($this->cache_dir);
if (!$dir)
{
return;
}
while (($entry = readdir($dir)) !== false)
{
if (strpos($entry, 'sql_') !== 0)
{
continue;
}
if (!($handle = @fopen($this->cache_dir . $entry, 'rb')))
{
continue;
}
// Skip the PHP header
fgets($handle);
// Skip expiration
fgets($handle);
// Grab the query, remove the LF
$query = substr(fgets($handle), 0, -1);
fclose($handle);
foreach ($table as $check_table)
{
// Better catch partial table names than no table names. ;)
if (strpos($query, $check_table) !== false)
{
$this->remove_file($this->cache_dir . $entry);
break;
}
}
}
closedir($dir);
return;
}
if (!$this->_exists($var_name))
{
return;
}
if ($var_name[0] == '_')
{
$this->remove_file($this->cache_dir . 'data' . $var_name . ".$phpEx", true);
}
else if (isset($this->vars[$var_name]))
{
$this->is_modified = true;
unset($this->vars[$var_name]);
unset($this->var_expires[$var_name]);
// We save here to let the following cache hits succeed
$this->save();
}
}
/**
* Check if a given cache entry exist
*/
function _exists($var_name)
{
if ($var_name[0] == '_')
{
global $phpEx;
return file_exists($this->cache_dir . 'data' . $var_name . ".$phpEx");
}
else
{
if (!sizeof($this->vars))
{
$this->load();
}
if (!isset($this->var_expires[$var_name]))
{
return false;
}
return (time() > $this->var_expires[$var_name]) ? false : isset($this->vars[$var_name]);
}
}
/**
* Load cached sql query
*/
function sql_load($query)
{
// Remove extra spaces and tabs
$query = preg_replace('/[\n\r\s\t]+/', ' ', $query);
if (($rowset = $this->_read('sql_' . md5($query))) === false)
{
return false;
}
$query_id = sizeof($this->sql_rowset);
$this->sql_rowset[$query_id] = $rowset;
$this->sql_row_pointer[$query_id] = 0;
return $query_id;
}
/**
* Save sql query
*/
function sql_save($query, &$query_result, $ttl)
{
global $db;
// Remove extra spaces and tabs
$query = preg_replace('/[\n\r\s\t]+/', ' ', $query);
$query_id = sizeof($this->sql_rowset);
$this->sql_rowset[$query_id] = array();
$this->sql_row_pointer[$query_id] = 0;
while ($row = $db->sql_fetchrow($query_result))
{
$this->sql_rowset[$query_id][] = $row;
}
$db->sql_freeresult($query_result);
if ($this->_write('sql_' . md5($query), $this->sql_rowset[$query_id], $ttl + time(), $query))
{
$query_result = $query_id;
}
}
/**
* Ceck if a given sql query exist in cache
*/
function sql_exists($query_id)
{
return isset($this->sql_rowset[$query_id]);
}
/**
* Fetch row from cache (database)
*/
function sql_fetchrow($query_id)
{
if ($this->sql_row_pointer[$query_id] < sizeof($this->sql_rowset[$query_id]))
{
return $this->sql_rowset[$query_id][$this->sql_row_pointer[$query_id]++];
}
return false;
}
/**
* Fetch a field from the current row of a cached database result (database)
*/
function sql_fetchfield($query_id, $field)
{
if ($this->sql_row_pointer[$query_id] < sizeof($this->sql_rowset[$query_id]))
{
return (isset($this->sql_rowset[$query_id][$this->sql_row_pointer[$query_id]][$field])) ? $this->sql_rowset[$query_id][$this->sql_row_pointer[$query_id]++][$field] : false;
}
return false;
}
/**
* Seek a specific row in an a cached database result (database)
*/
function sql_rowseek($rownum, $query_id)
{
if ($rownum >= sizeof($this->sql_rowset[$query_id]))
{
return false;
}
$this->sql_row_pointer[$query_id] = $rownum;
return true;
}
/**
* Free memory used for a cached database result (database)
*/
function sql_freeresult($query_id)
{
if (!isset($this->sql_rowset[$query_id]))
{
return false;
}
unset($this->sql_rowset[$query_id]);
unset($this->sql_row_pointer[$query_id]);
return true;
}
/**
* Read cached data from a specified file
*
* @access private
* @param string $filename Filename to write
* @return mixed False if an error was encountered, otherwise the data type of the cached data
*/
function _read($filename)
{
global $phpEx;
$file = "{$this->cache_dir}$filename.$phpEx";
$type = substr($filename, 0, strpos($filename, '_'));
if (!file_exists($file))
{
return false;
}
if (!($handle = @fopen($file, 'rb')))
{
return false;
}
// Skip the PHP header
fgets($handle);
if ($filename == 'data_global')
{
$this->vars = $this->var_expires = array();
$time = time();
while (($expires = (int) fgets($handle)) && !feof($handle))
{
// Number of bytes of data
$bytes = substr(fgets($handle), 0, -1);
if (!is_numeric($bytes) || ($bytes = (int) $bytes) === 0)
{
// We cannot process the file without a valid number of bytes
// so we discard it
fclose($handle);
$this->vars = $this->var_expires = array();
$this->is_modified = false;
$this->remove_file($file);
return false;
}
if ($time >= $expires)
{
fseek($handle, $bytes, SEEK_CUR);
continue;
}
$var_name = substr(fgets($handle), 0, -1);
// Read the length of bytes that consists of data.
$data = fread($handle, $bytes - strlen($var_name));
$data = @unserialize($data);
// Don't use the data if it was invalid
if ($data !== false)
{
$this->vars[$var_name] = $data;
$this->var_expires[$var_name] = $expires;
}
// Absorb the LF
fgets($handle);
}
fclose($handle);
$this->is_modified = false;
return true;
}
else
{
$data = false;
$line = 0;
while (($buffer = fgets($handle)) && !feof($handle))
{
$buffer = substr($buffer, 0, -1); // Remove the LF
// $buffer is only used to read integers
// if it is non numeric we have an invalid
// cache file, which we will now remove.
if (!is_numeric($buffer))
{
break;
}
if ($line == 0)
{
$expires = (int) $buffer;
if (time() >= $expires)
{
break;
}
if ($type == 'sql')
{
// Skip the query
fgets($handle);
}
}
else if ($line == 1)
{
$bytes = (int) $buffer;
// Never should have 0 bytes
if (!$bytes)
{
break;
}
// Grab the serialized data
$data = fread($handle, $bytes);
// Read 1 byte, to trigger EOF
fread($handle, 1);
if (!feof($handle))
{
// Somebody tampered with our data
$data = false;
}
break;
}
else
{
// Something went wrong
break;
}
$line++;
}
fclose($handle);
// unserialize if we got some data
$data = ($data !== false) ? @unserialize($data) : $data;
if ($data === false)
{
$this->remove_file($file);
return false;
}
return $data;
}
}
/**
* Write cache data to a specified file
*
* 'data_global' is a special case and the generated format is different for this file:
* <code>
* <?php exit; ?>
* (expiration)
* (length of var and serialised data)
* (var)
* (serialised data)
* ... (repeat)
* </code>
*
* The other files have a similar format:
* <code>
* <?php exit; ?>
* (expiration)
* (query) [SQL files only]
* (length of serialised data)
* (serialised data)
* </code>
*
* @access private
* @param string $filename Filename to write
* @param mixed $data Data to store
* @param int $expires Timestamp when the data expires
* @param string $query Query when caching SQL queries
* @return bool True if the file was successfully created, otherwise false
*/
function _write($filename, $data = null, $expires = 0, $query = '')
{
global $phpEx;
$file = "{$this->cache_dir}$filename.$phpEx";
if ($handle = @fopen($file, 'wb'))
{
@flock($handle, LOCK_EX);
// File header
fwrite($handle, '<' . '?php exit; ?' . '>');
if ($filename == 'data_global')
{
// Global data is a different format
foreach ($this->vars as $var => $data)
{
if (strpos($var, "\r") !== false || strpos($var, "\n") !== false)
{
// CR/LF would cause fgets() to read the cache file incorrectly
// do not cache test entries, they probably won't be read back
// the cache keys should really be alphanumeric with a few symbols.
continue;
}
$data = serialize($data);
// Write out the expiration time
fwrite($handle, "\n" . $this->var_expires[$var] . "\n");
// Length of the remaining data for this var (ignoring two LF's)
fwrite($handle, strlen($data . $var) . "\n");
fwrite($handle, $var . "\n");
fwrite($handle, $data);
}
}
else
{
fwrite($handle, "\n" . $expires . "\n");
if (strpos($filename, 'sql_') === 0)
{
fwrite($handle, $query . "\n");
}
$data = serialize($data);
fwrite($handle, strlen($data) . "\n");
fwrite($handle, $data);
}
@flock($handle, LOCK_UN);
fclose($handle);
if (!function_exists('phpbb_chmod'))
{
global $phpbb_root_path;
include($phpbb_root_path . 'includes/functions.' . $phpEx);
}
phpbb_chmod($file, CHMOD_READ | CHMOD_WRITE);
return true;
}
return false;
}
/**
* Removes/unlinks file
*/
function remove_file($filename, $check = false)
{
if ($check && !@is_writable($this->cache_dir))
{
// E_USER_ERROR - not using language entry - intended.
trigger_error('Unable to remove files within ' . $this->cache_dir . '. Please check directory permissions.', E_USER_ERROR);
}
return @unlink($filename);
}
}
?>
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