/**

*

* @package acm

* @version $Id: acm_file.php 9076 2008-11-22 19:06:42Z acydburn $

* @copyright (c) 2005 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()

	{

		global $phpEx;

		if (file_exists($this->cache_dir . 'data_global.' . $phpEx))

		{

			@include($this->cache_dir . 'data_global.' . $phpEx);

		}

		else

		{

			return false;

		}

		return true;

	}

	/**

	* 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 ($fp = @fopen($this->cache_dir . 'data_global.' . $phpEx, 'wb'))

		{

			@flock($fp, LOCK_EX);

			fwrite($fp, "vars = " . var_export($this->vars, true) . ";\n\n\$this->var_expires = " . var_export($this->var_expires, true) . "\n?>");

			@flock($fp, LOCK_UN);

			fclose($fp);

			if (!function_exists('phpbb_chmod'))

			{

				global $phpbb_root_path;

				include($phpbb_root_path . 'includes/functions.' . $phpEx);

			}

			phpbb_chmod($this->cache_dir . 'data_global.' . $phpEx, CHMOD_WRITE);

		}

		else

		{

			// Now, this occurred how often? ... phew, just tell the user then...

			if (!@is_writable($this->cache_dir))

			{

				trigger_error($this->cache_dir . ' is NOT writable.', E_USER_ERROR);

			}

			trigger_error('Not able to open ' . $this->cache_dir . 'data_global.' . $phpEx, E_USER_ERROR);

		}

		$this->is_modified = false;

	}

	/**

	* Tidy cache

	*/

	function tidy()

	{

		global $phpEx;

		$dir = @opendir($this->cache_dir);

		if (!$dir)

		{

			return;

		}

		while (($entry = readdir($dir)) !== false)

		{

			if (!preg_match('/^(sql_|data_(?!global))/', $entry))

			{

				continue;

			}

			$expired = true;

			@include($this->cache_dir . $entry);

			if ($expired)

			{

				$this->remove_file($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;

			}

			@include($this->cache_dir . "data{$var_name}.$phpEx");

			return (isset($data)) ? $data : false;

		}

		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] == '_')

		{

			global $phpEx;

			if ($fp = @fopen($this->cache_dir . "data{$var_name}.$phpEx", 'wb'))

			{

				@flock($fp, LOCK_EX);

				fwrite($fp, " " . (time() + $ttl) . ") ? true : false;\nif (\$expired) { return; }\n\n\$data =  " . (sizeof($var) ? "unserialize(" . var_export(serialize($var), true) . ");" : 'array();') . "\n\n?>");

				@flock($fp, LOCK_UN);

				fclose($fp);

				if (!function_exists('phpbb_chmod'))

				{

					global $phpbb_root_path;

					include($phpbb_root_path . 'includes/functions.' . $phpEx);

				}

				phpbb_chmod($this->cache_dir . "data{$var_name}.$phpEx", CHMOD_WRITE);

			}

		}

		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;

				}

				// The following method is more failproof than simply assuming the query is on line 3 (which it should be)

				$check_line = @file_get_contents($this->cache_dir . $entry);

				if (empty($check_line))

				{

					continue;

				}

				// Now get the contents between /* and */

				$check_line = substr($check_line, strpos($check_line, '/* ') + 3, strpos($check_line, ' */') - strpos($check_line, '/* ') - 3);

				$found = false;

				foreach ($table as $check_table)

				{

					// Better catch partial table names than no table names. ;)

					if (strpos($check_line, $check_table) !== false)

					{

						$found = true;

						break;

					}

				}

				if ($found)

				{

					$this->remove_file($this->cache_dir . $entry);

				}

			}

			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)

	{

		global $phpEx;

		// Remove extra spaces and tabs

		$query = preg_replace('/[\n\r\s\t]+/', ' ', $query);

		$query_id = sizeof($this->sql_rowset);

		if (!file_exists($this->cache_dir . 'sql_' . md5($query) . ".$phpEx"))

		{

			return false;

		}

		@include($this->cache_dir . 'sql_' . md5($query) . ".$phpEx");

		if (!isset($expired))

		{

			return false;

		}

		else if ($expired)

		{

			$this->remove_file($this->cache_dir . 'sql_' . md5($query) . ".$phpEx", true);

			return false;

		}

		$this->sql_row_pointer[$query_id] = 0;

		return $query_id;

	}

	/**

	* Save sql query

	*/

	function sql_save($query, &$query_result, $ttl)

	{

		global $db, $phpEx;

		// Remove extra spaces and tabs

		$query = preg_replace('/[\n\r\s\t]+/', ' ', $query);

		$filename = $this->cache_dir . 'sql_' . md5($query) . '.' . $phpEx;

		if ($fp = @fopen($filename, 'wb'))

		{

			@flock($fp, LOCK_EX);

			$query_id = sizeof($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);

			$file = "

			$file .= "\n\$expired = (time() > " . (time() + $ttl) . ") ? true : false;\nif (\$expired) { return; }\n";

			fwrite($fp, $file . "\n\$this->sql_rowset[\$query_id] = " . (sizeof($this->sql_rowset[$query_id]) ? "unserialize(" . var_export(serialize($this->sql_rowset[$query_id]), true) . ");" : 'array();') . "\n\n?>");

			@flock($fp, LOCK_UN);

			fclose($fp);

			if (!function_exists('phpbb_chmod'))

			{

				global $phpbb_root_path;

				include($phpbb_root_path . 'includes/functions.' . $phpEx);

			}

			phpbb_chmod($filename, CHMOD_WRITE);

			$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;

	}

	/**

	* 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);

	}

}

?>