What exactly does cleanAllSessions() does?

Question

I came accross a line Mage::app()->cleanAllSessions(); and going through the function I saw that it fetches the session save path and deletes it. i havent specified any session_save_path in my local.xml and have all my sessions saving in files, when i run this code it doesnt really clears the var/session folder, so what does it do actually?

FYI, calling session_save_path() returns c:\xampp\tmp.

Answer 1

Basically, session_save_path returns the path of the current directory used to save session data. We can set the path for it, ex: session_save_path('var/session'). If we didn't set any path value, the session data will store in the tmp folder of our web service. This is reason why when calling session_save_path(), it returns c:\xampp\tmp in your case.

Look into this file:

downloader/Maged/Controller.php

protected function cleanCache()
{
    ......     
    Mage::app()->cleanAllSessions();
    ......             

}

As we can see,Mage::app()->cleanAllSessions() is used for updating process. And, we don't set any value for session_save_path in this process, so, the tmp folder will store the session data. After updating successfully, we need to clear these values.

Now, we should find the session path of our Magento website.

Navigate to the core model session files:

app/code/core/Mage/Core/Model/Session/Abstract.php

public function getSessionSavePath()
{
        if (Mage::isInstalled() && $sessionSavePath = Mage::getConfig()->getNode(self::XML_NODE_SESSION_SAVE_PATH)) {
            return $sessionSavePath;
        }
        return parent::getSessionSavePath();
}

app/code/core/Mage/Core/Model/Session/Abstract/Varien.php

public function getSessionSavePath()
{
    return Mage::getBaseDir('session');
}

The session save path will be set if we have set this value in app/etc/local.xml. If not, it gets the path from Mage::getBaseDir('session') -> var/session will be used.

Try with an example:

app/etc/local.xml

<global>
    ......
    <session_save_path><![CDATA[var/store_session]]></session_save_path>
    ......
</global>

Print out the value:

app/code/core/Mage/Core/Model/Session/Abstract.php

public function getSessionSavePath()
{
        if (Mage::isInstalled() && $sessionSavePath = Mage::getConfig()->getNode(self::XML_NODE_SESSION_SAVE_PATH)) {
            var_dump($sessionSavePath);
            die;
            return $sessionSavePath;
        }
        return parent::getSessionSavePath();
}

object(Mage_Core_Model_Config_Element)#26 (1) { [0]=> string(17) "var/store_session" }