What's happening in future branch - April 19

[Ken Murchison]

When will all of this end up in CVS?  I've been distracted with other 
things for a while, but I still want to complete what's left of RFC 5524 
(BODYPARTSTRUCTURE).

There are also a few relatively trivial additions/fixes in bugzilla that 
I was going to hit today or tomorrow.



Bron Gondwana wrote:
> On Thu, Mar 25, 2010 at 10:28:53PM +1100, Bron Gondwana wrote:
>> index.c - use a mailbox object
>> ==============================
>>
>> All the globals go away!  There's just a global mailbox struct, which
>> will have a lock_fd in shared mode, meaning that all the offsets into
>> the cyrus.index and cyrus.cache mmaps are ALWAYS VALID.
>>
>> Along with compulsary CONDSTORE - vast swathes of code complexity are
>> being removed :)  You don't need to track times when you have modseq
>> to determine if flags should be sent again.  You don't have to keep
>> statting files, just re-read the header and then scan for updates.
>>
>> It WILL be necessary to keep a global array mapping from msgno to recno
>> so non-UID commands can be efficient.  This can be rewritten whenever
>> highestmodseq is detected to have changed :)
> 
> Not only have the globals in mailbox.c gone away, but I bit the bullet
> and rewrote index.c to use a "struct index_state" rather than globals
> as well - and then rewrote all the functions to take an index_state
> pointer rather than a mailbox pointer.  This means that you can have
> multiple index states open at once - which makes things like url_catenate
> not suck quite so hard!  Before they had to throw away all the mapping
> and re-create it...
> 
> Looking around the rest of the code - I think pop and nntp are all good.
> lmtp seems fine, though it's still untested at the moment.  I have a
> bunch of edge-case checking to do, but most of the everyday functions
> seem fine.
> 
> I have broken non-UID commands slightly, which will just required figuring
> out which instances of index_check need to get the "don't screw with
> EXPUNGES" flag set correctly, and that should be good.
> 
> The big TODO list contains:
> 
> * check QRESYNC behaviour, particularly with respect to ranges
> * test cyr_expire-esqe functionality.  Possibly split the cyr_expire tool
>   up in to 3 different tools that do one thing well rather than one which
>   does 3 things poorly.
> * replication - take advantage of the new fields.
> 
> There's still some thought required about cache_offset.  I'm in two minds
> about requiring the cache_offset to be the same at both ends, but the
> CRCs won't match up otherwise unless I add a separate "just the important
> fields" checksum!
> 
> There might be some benefit to doing that actually - because otherwise
> upgrades will kind of suck.  It would be good to have replication work
> reliably across point upgrades in to the future, but adding a field to
> the cached headers would break it.
> 
> Anyway - the code is going to look pretty unfamiliar to everyone!  Lots
> of changes.  Diffstat says over 6000 lines plus and over 8500 lines
> negative!  Still got a week and a bit to make it stable :)
> 
> Bron.
> 

-- 
Kenneth Murchison
Systems Programmer
Carnegie Mellon University