From: David Mazieres <dm-list-email-notmuch@scs.stanford.edu>
To: Sam Halliday <sam.halliday@gmail.com>, notmuch@notmuchmail.org
Subject: Re: github mirror
In-Reply-To: <87bnvn111h.fsf@Samskara.home>
References: <87bnvn111h.fsf@Samskara.home>
Date: Sun, 27 Apr 2014 12:04:45 -0700
Message-ID: <87iopu4mr6.fsf@ta.scs.stanford.edu>
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Reply-To: David Mazieres expires 2014-07-26 PDT
	<mazieres-8f7y82i34322d6mb5jb2bxwsmw@temporary-address.scs.stanford.edu>

Sam Halliday <sam.halliday@gmail.com> writes:

> Dear NotMuch,
>
> But in any case, my RFE/question was this: how hard would it be to have
> an optional mode of behaviour where tags are stored in the message
> itself, so that syncing with an IMAP server (e.g. via offlineimap)
> would make the tags available on all devices. This would negate the need
> for workarounds, such as shared notmuch databases, when users have
> multiple machines.

The problem is that different imap servers store tags in different
ways.  Since notmuch does not use imap, it would be hard for notmuch to
synchronize the tags, other than the standard ones (for which notmuch
already has support).

One thing you could do is build an external tool that synchronizes
notmuch tags and spawns an imap server in preauth mode to sync the tags.
(That would be yet another use for the ctime values we have discussed on
this list.)

> It would also allow applications like offlineimap to introduce a gmail
> plugin that would copy the message into a folder according to its tags,
> so gmail labels and notmuch tags would be in sync.

Unfortunately, offlineimap is dog slow, especially when you have a ton
of maildirs.  It just doesn't seem to pipeline very well at all.  Even
when I run 5 or 10 threads, it still seems to take a whole bunch of
round trip times.

I used to want what you want.  But then it got to the point that
offlineimap was taking 30 seconds to sync my 60 maildirs over 3G, even
when there was no new mail.  Worse, one thread seems to busy-wait for
the others to finish, so it often pegs the CPU and drains the battery on
my laptop.

As a result, I built a tool that synchronizes notmuch tags directly.
Now my problem is waiting for "notmuch new" to run, but at least the
synchronization part is really fast and pleasant.  I'll be releasing my
tool in the next couple of months once I've kicked the tires a bit more
and fixed up a few things.

David