bug#36714: 27.0.50; Gnus nnmaildir taking long time to recursively visit sub-Maildirs

[Eric Abrahamsen]

On 07/22/19 09:34 AM, Basil L. Contovounesios wrote:
> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>
>> Second of all... unfortunately I don't know this code well enough to
>> figure it out without sitting down with a chunk of time. So far as I can
>> tell, nnmaildir scans the maildir directories using `directory-files',
>> which by itself is very quick. Presumably what's slow is registering all
>> the messages inside the directories, and I don't immediately see a way
>> of preventing that.
>
> Would it be possible to do custom directory filtering in the
> 'directory-files' virtual server setting of the nnmaildir backend?

It might also be possible to make the building of nov files incremental:
ie only create them as messages are actually viewed. It would slow down
first-time viewing, and potentially fill up the same amount of disk
space, if you view all messages, but at least you'd have an operational
maildir installation faster.