[Koha-devel] Externalizing PO files (Was Re: externalising translator and etc)

[Galen Charlton]

Hi,

[Splitting the thread, there are two distinct topics being discussed.]

On Mon, Nov 15, 2010 at 4:16 AM, LAURENT Henri-Damien
<laurenthdl at alinto.com> wrote:
> Le 14/11/2010 22:51, Galen Charlton a écrit :

> From my understanding of Scott Chacon (a git developer) book and git
> talk, git stores the files in its database, since it is a DAG oriented
> SCM. It may send the diffs, but actualy stores the files.

A cursory reading of a Git book reveals that a statement that Git
"actually stores the files" is simplistic, at particular as far as the
implications for storage are concerned.  Please take a look at:

http://book.git-scm.com/7_how_git_stores_objects.html

Git's object storage takes the form of compressed version of each
object (commit, file, tag, etc.) a files and (and this is the
important part) packfiles.  Packfiles, roughly speaking, encode only
the changes to objects, so a significant amount of space is saved.

If one disabled automatic garbage collection in a git repo and never
ran git gc, you might end up with something close to storing the
(compressed) version of each changed file, but in practice that
doesn't happen.

> I don't think all the release tags would be broken.

As it turns out, they would.  I have actually tried running a git
filter-branch to remove the PO directory.  As I suspected, it does
rewrite all of the commits (thereby changing the commit IDs), and it
would be necessary to rewrite the tags.  But doing so would invalidate
the release tags that have a GPG signature.

Rewriting history like this is a sure way to get months of complaints
and calls for help on koha-devel with questions like "why does git
rebase origin no longer work".

> And it would allow to release localisation at a different pace... When
> there is a need.

There's is nothing stopping releasing localizations on a different
schedule now.  Packaging does not have any necessary connection with
how the Git repository is laid out.

I will grant that all other things being equal, it would have been a
valid choice to have the PO files live in a separate repository.  In
fact, we perhaps can still do so.  One thing that Chris Cormack
mentioned to me yesterday is that Pootle has a Git plugin which can
automatically commit changes to PO files to a repository.  That would
be a bit dangerous to allow for the main Koha repository, but safe
enough for a separate translations file.

Consequently, there is a possible compromise:

[1] We seed a new repository for PO files.
[2] We do a simple git rm misc/translator/po but *don't* rewrite history.

This won't reduce the size of the main repository, of course, but
achieves the separation.  And, to be honest, it's mostly the
possibility of integration with Pootle that would make me interested
in this.

However, since it is the translation manager who would be primarily
affected by the split on a day-to-day basis, I would be interested in
hearing from Frédéric as well as past TMs.

Regards,

Galen
-- 
Galen Charlton
gmcharlt at gmail.com