From 4011dba79b3b4bd7b747db2a774afe6bab217ed5 Mon Sep 17 00:00:00 2001
From: Ralf Becker <ralfbecker@outdoor-training.de>
Date: Fri, 17 Aug 2007 13:56:06 +0000
Subject: [PATCH] memcache session handler, which can deal with typical eGW
 sessions > 1MB (the one included in the pecl extension fails)

---
 phpgwapi/inc/functions.inc.php |   6 +-
 phpgwapi/inc/memcache.inc.php  | 110 +++++++++++++++++++++++++++++++++
 2 files changed, 115 insertions(+), 1 deletion(-)
 create mode 100644 phpgwapi/inc/memcache.inc.php

diff --git a/phpgwapi/inc/functions.inc.php b/phpgwapi/inc/functions.inc.php
index 2927f7e94b..b43f4eb1f7 100644
--- a/phpgwapi/inc/functions.inc.php
+++ b/phpgwapi/inc/functions.inc.php
@@ -53,7 +53,11 @@
 	}
 
 	include(EGW_API_INC.'/common_functions.inc.php');
-
+	
+	if (extension_loaded('memcache') && ini_get('session.save_handler') == 'memcache')
+	{
+		include(EGW_API_INC.'/memcache.inc.php');
+	}
 	// check if we can restore the eGW enviroment from the php-session
 	if ($GLOBALS['egw_info']['server']['sessions_type'] == 'php4-restore' && $_REQUEST['sessionid'])
 	{
diff --git a/phpgwapi/inc/memcache.inc.php b/phpgwapi/inc/memcache.inc.php
new file mode 100644
index 0000000000..8a2f172067
--- /dev/null
+++ b/phpgwapi/inc/memcache.inc.php
@@ -0,0 +1,110 @@
+<?php
+/**
+ * eGroupWare API - memcache session handler
+ *
+ * Fixes a problem of the buildin session handler of the memcache pecl extension, 
+ * which can NOT work with sessions > 1MB. This handler splits the session-data
+ * in 1MB junk, so memcache can handle them.
+ *
+ * To enable it, you need to set session.save_handler to 'memcache' and 
+ * session.save_path to 'tcp://host:port[,tcp://host2:port,...]', 
+ * as you have to do it with the original handler.
+ *
+ * @link http://www.egroupware.org
+ * @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @package api
+ * @subpackage session
+ * @copyright (c) 2007 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
+ * @version $Id$
+ */
+
+function egw_memcache_open($save_path, $session_name)
+{
+	global $egw_memcache_obj;
+	$egw_memcache_obj = new Memcache;
+	foreach(explode(',',ini_get('session.save_path')) as $path)
+	{
+		$parts = parse_url($path);
+		$egw_memcache_obj->addServer($parts['host'],$parts['port']);	// todo parse query
+	}
+	return(true);
+}
+
+function egw_memcache_close()
+{
+	global $egw_memcache_obj;
+	
+	return is_object($egw_memcache_obj) ? $egw_memcache_obj->close() : false;
+}
+
+define('MEMCACHED_MAX_JUNK',1024*1024);
+
+function egw_memcache_read($id)
+{
+	global $egw_memcache_obj;
+
+	$id = 'sess-'.$_REQUEST['domain'].'-'.$id;
+	for($data=false,$n=0; ($read = $egw_memcache_obj->get($id.'-'.$n)); ++$n)
+	{
+		$data .= $read;
+	}
+	return $data;
+}
+
+function egw_memcache_write($id, $sess_data)
+{
+	global $egw_memcache_obj;
+	
+	$lifetime = (int)ini_get('session.gc_maxlifetime');
+	// give anon sessions only a lifetime of 10min
+	if (is_object($GLOBALS['egw']->session) && $GLOBALS['egw']->session->session_flags == 'A')
+	{
+		$lifetime = 600;
+	}
+	$id = 'sess-'.$GLOBALS['egw_info']['user']['domain'].'-'.$id;
+	for($n=$i=0,$len=_bytes($sess_data); $i < $len; $i += MEMCACHED_MAX_JUNK,++$n)
+	{
+		if (!$egw_memcache_obj->set($id.'-'.$n,_cut_bytes($sess_data,$i,MEMCACHED_MAX_JUNK),0,$lifetime)) return false;
+	}
+	return true;
+}
+
+function _test_mbstring_func_overload()
+{
+	return @extension_loaded('mbstring') && (ini_get('mbstring.func_overload') & 2);
+}
+
+function _bytes(&$data)
+{
+	global $mbstring_func_overload;
+	
+	if (is_null($mbstring_func_overload)) _test_mbstring_func_overload();
+	
+	return $mbstring_func_overload ? mb_strlen($data,'ascii') : strlen($data);
+}
+
+function _cut_bytes(&$data,$offset,$len=null)
+{
+	global $mbstring_func_overload;
+	
+	if (is_null($mbstring_func_overload)) _test_mbstring_func_overload();
+	
+	return $mbstring_func_overload ? mb_substr($data,$offset,$len,'ascii') : substr($data,$offset,$len,'ascii');
+}
+
+function egw_memcache_destroy($id)
+{
+	global $egw_memcache_obj;
+	
+	$id = 'sess-'.$_REQUEST['domain'].'-'.$id;
+	for($n=0; $egw_memcache_obj->delete($id.'-'.$n); ++$n) ;
+	
+	return $n > 0;
+}
+
+function egw_memcache_gc($maxlifetime)
+{
+}
+
+session_set_save_handler("egw_memcache_open", "egw_memcache_close", "egw_memcache_read", "egw_memcache_write", "egw_memcache_destroy", "egw_memcache_gc");