Re: [PATCH 2/2] nnmaildir: Use a 'num' file, instead of a directory

[Ted Zlatanov <tzz@lifelogs.com>]

On Thu, 27 May 2010 15:09:08 -0600 John Wiegley <jwiegley@gmail.com> wrote: 

JW> This patch causes nnmaildir to use a "num" file to track the next
JW> available article number, rather than creating N empty files.
JW> However, this only works for new groups.  Existing groups, which use
JW> the directory, will continue to.  If you want to switch to using
JW> file-based numbering, you must convert your Maildir using the
JW> attached script (it's also copied to the commit description in the
JW> patch).

IIRC (and Paul Jarc may want to comment) something similar was discussed
in http://thread.gmane.org/gmane.emacs.gnus.general/66245/focus=66247

I'm not sure I want to give up concurrent spool access in nnmaildir so I
left things alone back then.  I have recently experienced slow nnmaildir
performance too (see
http://article.gmane.org/gmane.emacs.gnus.general/69723).  Maybe we can
make this a backend parameter, off by default, and ask whenever someone
creates a new nnmaildir backend in Gnus?  I don't think we need to
support the conversion you described, we should only support it for new
nnmaildirs.  What do you think?

Ted