Re: [imap5] ERASE command as part of MOVE

[Timo Sirainen <[e-mail]>]

On 2.6.2012, at 7.27, Bron Gondwana wrote:

>> It doesn't need to be an extra roundtrip. You can run uidexpunge even if store fails and it doesn't do anything bad. By avoiding the extra roundtrip it is possible for the server to optimize the STORE+EXPUNGE into equivalent of ERASE. (Dovecot does halfway that - it for example doesn't rename maildir files on STORE stage, just unlinks them on EXPUNGE.)
> 
> Not so easy if you want to delete the messages by sequence number of
> course.
> 
> TAG ERASE 1:10
> 
> Isn't implementable as a pipelined command, it would have to be
> 
> TAG1 STORE 1:10 +Flags \Deleted
> TAG2 UID EXPUNGE UID1,UID2,UID3,UID4,UID5..UID10

It can still be pipelined. You would of course need to know the UIDs.

> So how does Dovecot handle a crash or filesystem error during that
> intermediate stage?  Replay an action log?  

Yes.

> What if the file can't
> be renamed, but it's already replied to a client saying "yes, your
> flag store succeeded"?

The message gets marked as having "dirty flags" meaning the flags in index file should be used instead of the flags in maildir file.