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?

I guess it would be possible to set the directory-files setting to a
lambda that accepted the same arguments as `directory-files', and only
returned the desired folder. Again, I just don't know enough about the
inner workings of nnmaildir to say for sure.