Re: IMAP revisited

[Paul Franklin <paul@cs.washington.edu>]

>>>>> Sudish Joseph writes:

 > Scott Blachowicz <scott@statsci.com> writes:
 >> 3) don't have active files, etc on the server.

IMAP doesn't have to change to deal with this; LIST and EXAMINE can be
used.  However, it will be slow if the user has many mailboxes, as a
EXAMINE will be needed for each mailbox.

 >> 4) can maintain sequences/marks/etc on the server.

That's what nn*-request-update-info was created for.  I think.  It at
least provides a way for gnus to find out about changes on the server,
but I don't know if it allows gnus changes to propagate to the server.
This depends on when it is called.

 > Essentially, Gnus has to stop telling backends what the article
 > number of a message should be.  For starters.

I think this is too fundamental to Gnus to change.  However, the
mapping between Gnus message numbers and IMAP4 UIDs is the only thing
which needs to be stored locally to make this work.  (UIDs would work
if they didn't have gaps.  But I think some IMAP4 servers use
time-based values, and this leaves lots of gaps if you don't come
close to receiving one message per second.)

A lot of this could probably be patched over depending on when
nn*-request-update-info is called.  (Lars, is this documented yet?  It
isn't in red 0.47.)  The real killer is cached articles.

--Paul