Re: [Nmh-workers] nmh in near, medium, and far-term

[Paul Vixie]

On 12/6/2011 8:43 PM, Ken Hornstein wrote:
>>> Alright, I'll the limits of my knowledge here.  UIDL is a POP thing,
>>> right?  Do you mean UID when talking about IMAP?

yes.

>>> It seems that IMAP has the concept of a "message sequence number",
>>> which is a number from 1 to the number of messages in a folder; that
>>> might be the right thing to use.

no. MH message numbers can have holes and can be reassigned. IMAP is
always 1..N, no holes.
>>> Of course it's not clear to me how
>>> Dovecot maps a message number into a particular filename; I'll have to
>>> look at that.

the UID is not like the IMAP sequence number. UID is a unique number
that never changes for the lifetime of that message in that folder. for
example a message in my "Archives.2011" folder has this full pathname.

Maildir/.Archives.2011/cur/1321741485.M572952P74802.ss.vix.com,S=1369,W=1407:2,FR

i'm not sure exactly what all that crap is or means, "1321741485" looks
like a seconds-since-1970, and "M572952P74802" looks a little like
device+inode. i don't know how Dovecot gets from that file name to an
IMAP UID and i don't know if it does so in a Dovecot specific way or
whether this is a Maildir thing (Dovecot-independent).

the reason i'm thinking that we'll have a .dir/.pag file per folder is
to make sure that MH message number "X" remains more stable than an IMAP
message number would be, but less stable than an IMAP UID would be. we'd
generate this "db" the first time we visit a folder, we'd regenerate it
if the directory mtime was more recent than the "db" mtime, and we'd
update this db whenever we ran "inc", "refile", "pack", "rmm" or
"sortm", and we'd access this db whenever we ran "show" or "inc" or
"repl" or similar.