User directory hashing

[Tucsek János]

Title: User directory hashing

Hi,

Does anybody know, how to turn on directory hashing on users directory?
So, for example:
Our user's messages are in:

/imap/domain/foobar.com/user/foo
.
.
/imap/domain/foobar.com/user/bar

directories.

And the question is: is there any directory hashing patch to cyrus ( 2.2+ version ),
what will make something like this with directories:

/imap/domain/foobar.com/user/f/fo/foo
.
.
/imap/domain/foobar.com/user/b/ba/bar

Because we have approx. 20-25 thousand user under one domain dir (free mail service),
and when doing a backup it tooks a lot of time to get the directory listing...

I found that there is a fulldirhash configure option, but it hashes only the domain name,
not the user's dir, so for example with fulldirhash the directory seems to be like that: /imap/domain/f/foobar.com/...

Any ideas?

Thanks,
Janos Tucsek