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

[Derek Scherger]

On Wed, 2 Feb 2005, Christof Petig wrote:

> Taking heads as a template I see that the usual way would be to fetch
> every revision which belongs to the branch (get_revision_certs(branch))
> and then call erase bogus_certs, then iterate over the list of revisions
> to find matching cvs_revision certs and corresponding date certs.
                                          ^^^^^^^^^^^^^^^^^^

Of which there may be several. One thing I've wondered a few times is 
whether all certs should simply have date and possibly author fields in 
them. Currently it's difficult (and impossible after a db rebuild) to 
assciate date/author/changelog certs together which isn't a big problem 
until there are multiple date/author/changelog certs on some revision. 
Then you have a rather hard time deciding who said what when.

Without the date in particular, it seems like the statement made in a cert 
is missing an important bit of context - when the statement was made. 
After a db rebuild and the cert is signed by whomever did the rebuild 
another important bit of context is also lost - who originally made the 
statement (the author).

> Even more efficient would be to query for the revision which corresponds
> to the maximum of the date cert (sadly base64 encoding does not preserve
> sort order - another reason to start using BLOBs) and which has a cert

If all certs had a raw string date in them this would be an easier thing 
to query by.

Currently each revision has (or should probably have) at least 4 certs:

        - date
        - author
        - changelog
        - branch

If date and author were added to each cert this could be reduced to 2 
certs:

        - changelog
        - branch

and there was some talk on irc recently about how much space all these 
certs consume due to their cryptographic signatures. Perhaps reducing the 
cert count by adding date and author info to each cert could help with 
this problem too?

Cheers,
Derek