DOM Storage & UserData Persistence

[VanguardLH]

Any idea of when cleanup will include DOM and user persistent data (local storage objects) under the Internet Explorer cleanup category? Below is my canned comment to users that don't understand that .txt cookies aren't the only means of saving data on their host from a server. LSO can be used to store information on the user's host and, for example, can also be used to track their web navigation. I have disabled both DOM Storage and UserData Persistence options in IE8 but this could interfere with the operation of some sites; for example, they may want to use local storage for data used by a script on their web page that I visit. When I am no longer at the site, and especially after exiting the web browser, I don't want this data stored on my host. My property is not to be used for their storage.

 

Also, under your Multimedia category, you list Adobe Flash Player but don't mention just what gets cleaned up. Maybe that means deleting the .sol cookie files used for local storage by Flash. However, if you delete the global .sol cookie file then the user loses all their settings for the ActiveX control for Flash (which can include settings to NOT let the control use any local storage to pollute their host). I currently have the Flash Player configured to NOT allow for local storage but if CCleaner deletes the global .sol cookie (%appdata%\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys\settings.sol) then I lose my settings and am back to the defaults which does allow local storage.

 

- CCleaner should add cleanup for DOM Storage and persistent user data.

- CCleaner should not delete the global .sol cookie that hold the user's settings for Flash Player.

- docs.piriform.com should get updated to include a Tech Specs section to let users know exactly WHAT cleanup actions are perform by each setting under Windows and Applications tabs.

 

 

-- DOM Storage and UserData Persistence

 

Cookies only allow a small amount of storage on your host: typically 300 cookies total, 20 cookies per domain, 4096 bytes per cookie. These are the recommended minimums [but are *not* required] by RFC 2109. IE goes its own way with a maximum cookie count of 20 (but got upped to 50) with a total of 4096 bytes maximum consumed by all cookies (upped to 10KB in IE8); see http://blogs.msdn.com/ieinternals/archive/2009/08/20/WinINET-IE-Cookie-Internals-FAQ.aspx. You'll have to do your own research regarding maximums in other web browsers. Some web servers also have their own maximums. Apache will fail with "Size of a request header field exceeds server limit" if the total of all cookies retrieved by the Cookie: request header exceeds 8190 bytes.

 

For info on .txt cookies: http://en.wikipedia.org/wiki/Http_cookie

 

Another source of cookies are with Flash which has its own .sol files. You can manage how big they can become or if any are saved on your host at all. Visit http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager.html and go under Global Settings to configure if any local storage is used.

 

For info on .sol cookies: http://en.wikipedia.org/wiki/Flash_cookie

 

Cookies are not the only means of saving site data (euphemistically called "user data" for a site) on your host. User persistent data is a separate cache and allows far more storage of site data on your host. Check if you have the following options enabled:

 

Internet Options

 

- Advanced tab

Security section

Enable DOM Storage

 

- Security tab

<pick a security zone, like Internet>

Custom Level

Miscellaneous section

Userdata persistence

 

See:

 

http://msdn.microsoft.com/en-us/library/cc197062(VS.85).aspx

http://en.wikipedia.org/wiki/DOM_storage

https://developer.mozilla.org/En/DOM:Storage#Description

 

DOM storage is new as of IE8 (http://dev.w3.org/html5/webstorage/). As I recall, the persistent data is stored under the %userprofile%\UserData folder for IE. Other web browsers have their own DOM storage location (e.g., Firefox uses an SQLlite file). I've had these options disabled for so long and probably did cleanup at the time that there is nothing to find on my host under this folder. There may be freeware that not only purges the classic .txt cookies (and possibly the Flash .sol cookies) but also the UserData records.

[VanguardLH]

I was going to send the suggestion via the "Contact Us" web form but that page pukes on submit with the following errors:

 

Server Error in '/' Application.
--------------------------------------------------------------------------------

Runtime Error 
Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine. 

Details: To enable the details of this specific error message to be viewable on remote machines, please create a <customErrors> tag within a "web.config" configuration file located in the root directory of the current web application. This <customErrors> tag should then have its "mode" attribute set to "Off".


<!-- Web.Config Configuration File -->

<configuration>
   <system.web>
       <customErrors mode="Off"/>
   </system.web>
</configuration>


Notes: The current error page you are seeing can be replaced by a custom error page by modifying the "defaultRedirect" attribute of the application's <customErrors> configuration tag to point to a custom error page URL.


<!-- Web.Config Configuration File -->

<configuration>
   <system.web>
       <customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"/>
   </system.web>
</configuration>

 

Posting here might be the better place but the Contact Us web form page (http://www.piriform.com/contact) needs to get fixed.

[Guest MrT]

Thanks, we'll look into this.