[darcs-users] More efficient and automated use of checkpoints?

[David Roundy]

On Fri, Oct 14, 2005 at 10:36:58AM +0200, Gaetan Lehmann wrote:
> 
> About checkpoints, is there a chance to see the bug in "darcs get  
> --partial" fixed soon ?
> The test to see that bug is really simple:
> 
> [glehmann at pcconf5 darcs]$ ./darcs get --partial --tag=1.0.3  
> http://www.abridgegame.org/repos/darcs/
> Welcome to the darcs darcs repository!
> 
> This is the stable release branch.
> **********************
> Directory '/home/glehmann/tmp/darcs/darcs' already exists, creating  
> repository as '/home/glehmann/tmp/darcs/darcs_0'
> Copying patch 121 of 121... done!
> Applying patch 120 of 120... done.
> darcs: failed to read patch in get_extra:
> Sun Jul 31 14:04:58 CEST 2005  David Roundy <droundy at abridgegame.org>
>   * add changelog entry and building darcsgit section to manual.
> Perhaps this is a 'partial' repository?

I guess there are two ways to "fix" this.  One is to declare that it's an
error-message bug, and fix get to declare that it can't get a partial
repository at tag 1.0.3, since that version's too old.

The other (better) solution is to make darcs smart enough to realize that
it needs to try an earlier checkpoint in order to get version 1.0.3.  This
is potentially complicated.  Mostly, we'd need some logic to be able to
figure out which checkpoint we need, which means get_checkpoint to look at
what version is being asked for, and then return an appropriate
checkpoint.  Maybe this wouldn't be too hard... and with care we might even
improve diff performance with the same change.
-- 
David Roundy
http://www.darcs.net