BUG: Internet Explorer's Stray File Problem |
If you interrupt the transfer of a web page before it is finished by clicking on a link to go to another page, many incomplete files that were in the process of downloading will get lost and become "stray files" in the cache. These stray files aren't recorded in the cache index, so neither Internet Explorer nor CacheSentry see them under normal circumstances. They end up taking up space on the hard drive and clearing the cache with IE4 and earlier does not remove them! CacheSentry fixes this bug by finding them and cleaning up the stray files and stray cookies for you, leaving the rest of the cache intact.
An opposite problem can also occur on rare occasions, where the record to an item of content in the cache index exists but the physical file in the cache folder has been deleted. This is a "stray URL", and CacheSentry also removes stray URLs for you automatically if you wish.
In Internet Explorer 5, it seems to remove certain stray files when it needs to make room in the cache. However, after testing Internet Explorer 5 without CacheSentry running for a few months, I have found it still seems to forget about some files and they never seem to be deleted. (The same is true for 5.5 and IE6.) When you empty the cache with Internet Explorer 5, it does delete both the regular cached files and stray files, so that part of the bug is fixed.
Outlook Express 5.5 and 6.0 Issue
It has come to my attention that Outlook Express now uses the IE cache folders to store thousands of small files related in some way to its operation, most of which are zero bytes in size. Unfortunately, it is not clear whether IE ever removes all of them. CacheSentry's stray file removal code automatically removes these files after they aren't used for a day or two. CacheSentry can now also be directed to only remove the zero-byte files if you wish.