Rollback functionality for apt-rpm

[Panu Matilainen]

On Tue, 30 Jan 2007, João Abecasis wrote:

> Hi everyone!
>
> I'm writing this to report on the state of affairs wrt to the rollback
> functionality. We are currently maintaining two ports of the patch I
> initially submitted here, one for apt-rpm and another for Debian's
> apt. To that end, I've set up two branches in our svn repository,
> containing patched versions of the upstream trees, respectively
> apt-0.5.15lorg3.2 and apt-0.6.46.4.
[...]
> Panu Matilainen wrote:
>> - You certainly do NOT want to store rollback database in /var/cache/apt,
>> that data is supposed to be just a cache that can be recreated at any time
>> from information available elsewhere. 'rm -f /var/cache/apt/*.bin' is
>> a common method for cleaning up the package cache if it has gotten screwed
>> somehow. The package data can be restored from package indexes, the
>> rollback history not. So I'd suggest moving it to /var/lib/apt (or rather,
>> Dir::State) instead.
>
> This has been changed in svn.

Ok, good. I see the pkgcfg location has also been changed to the statedir 
which is something I intended to mention earlier but forgot :)

> A new option has also been added to the
> configure scripts, such that rollback functionality is now disabled by
> default. It can be enabled with,
>
>    ./configure --enable-rollback
>
> Disabling rollback also removes dependencies on sqlite3 libraries. For
> the time being, this was accomplished by locally defining stub
> versions of the sqlite functions in use.
> A better option, for the future, is to separate the database access 
> functionality from pkgRollbackManager, allowing different database 
> implementations (at least a dummy and an sqlite3 would be implemented in 
> this scenario).

I'll have a look at abstracting out the database access when merging this. 
Yes, consider this a promise to merge it. Hmm, I wonder if I already 
promised that... I'll just blame this damn flu for any memory failures :)

I'm working on something else right now that also needs sqlite3, so the 
build-checks and switches for sqlite3 dependency will need some tweaking 
etc, but I'll sort it out when the time comes.

 	- Panu -