I don't know if this the right forum, but it'll do.

I'll like into look at the possibility changing the block cache so that the pages are cached by user group. The current cache causes strange problems with other user groups seeing things that they should not; when multiple user groups are logged on. This means that I have to turn the page cache off for a lot of the pages, thus making the site slower.

So can anybody give me a list of the PHP files that manage the cache so I can have a look at them?

Thanks in advance.
Terry.