Re: RFC/Pull Request: Refs db backend

[David Turner <dturner@twopensource.com>]

On Tue, 2015-06-23 at 10:16 -0700, Stefan Beller wrote:
> > The db backend code was added in the penultimate commit; the rest is
> > just code rearrangement and minor changes to make alternate backends
> > possible.  There ended up being a fair amount of this 
> > rearrangement,  but the end result is that almost the entire git 
> > test suite runs under the db backend without error (see below for 
> details).
> 
> Looking at the end result in refs-be-db.c it feels like there are more
> functions in the refs_be_db struct, did this originate from other 
> design choices? IIRC Ronnie wanted to have as least functions in 
> there as possible, and share as much of the code between the 
> databases, such that the glue between the db and the refs code is 
> minimal.

I didn't actually spend that much time reading Ronnie's backend code.
My code aims to be extremely thoroughly compatible.  I spent a ton of
time making sure that the git test suite passed.  I don't know if an
alternate approach would have been as compatible.

The requirement for reflog storage did complicate things a bit.

I also didn't see a strong need to abstract the database, since LMDB is
common, widely compatible, and tiny.  

> Some random comments from looking over the branch briefly:
> 
> In the latest commit, (refs: tests for db backend), I am unsure about 
> the copyright annotations. At least a sole "Copyright (c) 2007 Junio C
> Hamano" doesn't make sense to me. ;)

Will fix, thanks.

> Typo in commit message "bisect: use refs insfrastructure for 
> BISECT_START"

Will fix, thanks.

> Some commits contain a ChangeId, which is a Gerrit leftover. :(

Those were leftover from Ronnie's patches; since you are a Googler and
you think we don't need them, I'll remove them.