Re: [Monotone-devel] How to get the newest cert beginning with a certain substring?

[Nathaniel Smith]

On Wed, Feb 02, 2005 at 10:24:41AM +0100, Christof Petig wrote:
> Now to start an update I need to ask for
> - the latest (using the date) cert and revision for a given
> host+repository+module.
> (- Perhaps every cert and revision matching the given module)

I think the answer is that you don't want to use the date cert.  You
want to use the ordering imposed by ancestry.

The model is similar to 'heads' -- 'heads' finds revisions that have a
given branch cert, that have no descendents that have that same branch
cert.  s/branch/cvs_revision/ and you have exactly what you want to do
here.

> This brings me to another question: This cert is highly compressible and
> also changes not much between revisions. This brings this cert near to
> file characteristics. Is it planned to reference files (or any other
> diff+gzip stored entity) from certs (I know this opens a can of worms
> when it comes to synchronization)? Perhaps not, but once this topic
> comes up a second or third time, I would suggest to implement it.

It's tricky, since cert values need to be SELECT'ed on (at least,
branch cert values do), and IIUC gzipped data is not necessarily
normalized.  Random idea - store the information in a .mt file in the
filesystem?  Then a cert could be used to say "this revision has an
up-to-date .mt-cvs", and nothing else.  Could actually use .mt-attr
for this, though at some risk of annoying people by cluttering it
up with stuff they shouldn't touch...

-- Nathaniel

-- 
"But in Middle-earth, the distinct accusative case disappeared from
the speech of the Noldor (such things happen when you are busy
fighting Orcs, Balrogs, and Dragons)."