[Dovecot] dbox redesign

[Timo Sirainen]

On Wed, 2007-05-16 at 20:27 +0200, Gunter Ohrner wrote:
> Am Mittwoch, 16. Mai 2007 schrieb Timo Sirainen:
> > > Yes, I think treating mailboxes similary to keywords is ideal.  There
> > Except if you want to handle some mailboxes in a special way it's
> > easier if they're separated on disk. Such as renaming or deleting
> > mailboxes is a lot easier.They're based on filtering rules. I don't 
> think they support "copying"
> messages. So the virtual folders are easily rebuilt by just re-applying
> the filters into all the messages.
> 
> Not neccessarily if you add one level of indirection, simply numbering the 
> mailboxes by index numbers internally and providing a number/name mapping 
> somewhere. This way, a mailbox can be renamed easily simply by updating 
> the map, and might by deleted by removing the map entry. Stale index 
> number may be left in the messages and might cleaned up the next time a 
> message's folder list is updated or messages are expunged.

Right. This would also make it use less space inside the dbox files.
There already exists a mailbox list index in v1.1 which contains mailbox
ID <-> name mappings. But I'm still a bit concerned of its stability.
There are two things that could be done:

1) Have another human readable mailbox ID <-> name mapping file which is
used if the binary index is corrupted. If mailboxes are
created/deleted/renamed often, this would just slow things down. Might
be a good idea optionally though.

2) If the ID <-> name mapping is lost, the mailboxes could be created
using those IDs as their names. That would be a lot better than just
having all the mails merged into a single mailbox. As additional help,
there could be a couple of built-in mailbox IDs for INBOX, Trash and
Drafts. Perhaps that could be admin-configurable, but then again adding
new IDs could make it conflict with existing ones. Perhaps just a single
1=INBOX would be enough..

The mailbox IDs could have a validity number as well, similar to
UIDVALIDITY for message UIDs. That would make sure that it's safe to use
the validity+ID combination to uniquely and permanently identify a
mailbox, even if the mailbox list mapping was completely rebuilt (in
that case it would get a new validity).
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
Url : http://dovecot.org/pipermail/dovecot/attachments/20070519/d5ad39d9/attachment.pgp