[Dovecot] IMAP IDLE, Virtual mailboxes

[Timo Sirainen]

On 9.4.2010, at 9.31, Patrick Nagel wrote:

> 2) Enhancing dovecot's Virtual plugin, so virtual mailboxes do not only
> get updated on select and expunge, but also when anything changes that
> affects the set of messages shown in the virtual mailbox. I guess that
> would have an impact on performance, and thus should be optional.

Virtual plugin does already work like that. Although there's a bug where messages don't get removed from mailbox always:

 - virtual: removed messages don't get expunged unless EXPUNGE is issued in
   same session. otherwise they get forgotten and never removed.

And NOTIFY isn't implemented yet mainly because it would be annoyingly expensive (as is virtual mailbox when it's created from many real mailboxes). I've been planning on implementing mailbox list indexes (or they already are implemented, but they're buggy) that would make this much cheaper. Basically NOTIFY could just keep watching for changes to dovecot.list.index.log file, and then read what mailbox had changed and how and notify client about it, possibly without even opening the mailbox itself.