[pacman-dev] pacman transactions

[Dan McGee]

On Wed, Mar 6, 2013 at 8:04 AM, Renan Biegelmeyer
<renan.biegel at gmail.com> wrote:
> Hello,
> I'm trying to understand, in pacman/libalpm code how the transactions work.
> Are they atomic? If so, the transactions are only atomic for the local
> database or they are also atomic for the instalation/upgrade/removal of the
> packages in the system?

They are not atomic, on either the database level or the filesystem
level. The word transaction was misused here for sure; it predates all
of the current maintainers. Don't see it so much as a database
transaction as "Once you call alpm_<sync|remove|upgrade>_commit, I'm
reasonably certain I will be able to complete the operation without
issue."

We've yet to have reports of total local database corruption or
anything; this bit could be made to operate in a more atomic manner
using rename and such but we haven't done so.

-Dan