Re: [AD] git-svn and allegro?

[Thomas Fjellstrom <tfjellstrom@xxxxxxxxxx>]

On January 16, 2009, Peter Wang wrote:
> On 2009-01-16, Thomas Fjellstrom <tfjellstrom@xxxxxxxxxx> wrote:
> > I hear you might be using git-svn with allegro.. I was wondering what it
> > takes to set that up and work with it.. How do you work with allegro?
>
> Hi Thomas,
>
> I thought others might be interested in this as well.  We should put it
> on the web site, too.  Let me know if there are any errors.
>
> The only hard part about using git-svn is indeed the setting up.
> Here is a little guide.  You will need the Subversion Perl bindings in
> addition to git itself.
>
>
> The easy way
> ============
>
> Converting a copy of the SVN repository to git takes a long time.
> Luckily for you, I've already done it.  You can download it from
>
> http://alleg.sourceforge.net/files/git/allegro-git-20090117.tar.bz2
> http://alleg.sourceforge.net/files/git/authors.txt
>
> The authors.txt file it maps SVN usernames to author names.  Everyone
> who has committed needs to be listed (so you might need to add to it
> occasionally).  Don't worry about the phony email addresses.
>
>     % tar jxf allegro-git-20090117.tar.bz2
>     % cd allegro.git
>     % git config svn.authorsfile /path/to/authors.txt
>     % git checkout -f
>
> Now you can do your first update:
>
>     % git svn rebase
>
> For interest's sake, instructions for converting the repository yourself
> are at the end of this message.
>
>
> Using git-svn
> =============
>
> Working
> -------
>
> Do your work in this workspace, making local commits with git.  I think
> the git-svn documentation suggests you leave the 'master' branch
> containing only the public changes from SVN, so do your work in another
> branch:
>
>     % git checkout -b myfeature
>     # hack hack hack
>     % git commit -a
>
> You can see all the branches and tags with:
>
>     % git branch -r
>
>
> Updating from SVN
> -----------------
>
> First make sure there are no uncommitted changes, then run:
>
>     % git svn rebase
>
> Your local changes on the current branch will be put on top of the
> public changes.  You can also download and rebase separately, which is
> useful for rebasing multiple local branches.
>
>     % git svn fetch
>     % git svn rebase -l
>
> If you do have uncommitted changes lying around, you can either make a
> temporary commit, which you undo later, or use the `git stash` feature.
> I usually do the former as I forget about things I've stashed.
> Undoing the top commit is simple:
>
>     % git reset HEAD~1
>
>
> Publishing changes
> ------------------
>
> You can publish your local changes to SVN with:
>
>     % git svn dcommit
>
> I usually run `git svn dcommit -n` first just to check it's the expected
> number of changes.  `git log` will tell you what the changes are.
>
> Don't feel like you have to publish every local change immediately.
> If you leave it for a while you'll probably think of something that you
> forgot.  Then you can amend the change locally, saving yourself some
> embarrassment (and keeping our SVN history a bit cleaner).
>
> SourceForge's servers aren't the fastest, so it's nice to batch up
> changes then let `dcommit` be patient while you do something else.
>
>
> Cloning the repository
> ----------------------
>
> Normally you'd use `git clone` to make a copy of a repository, but
> unfortunately that won't keep the metadata required for `git-svn`.
> Just make a plain copy, say, using rsync.
>
>
> Finally, if you're new to `git`, here are some of my favourite commands
> which you won't find in `svn` (at least, easily):
>
> * git commit --amend
> * git rebase -i
> * git diff --color-words
> * git grep
> * git show
> * git log -p
> * git add -p
>
> Peter
>
>
> Converting the repository
> =========================
>
> This is not strictly necessary, but I recommend mirroring the SVN
> repository to the local disk before attempting a conversion.
> If something goes wrong you won't have to download everything from
> SourceForge again.  The repository is more than 170 MB.
>
>     % SVN_MIRROR=/path_to_store_at/alleg
>     % mkdir -p $SVN_MIRROR
>     % rsync -c -av alleg.svn.sourceforge.net::svn/alleg/'*' $SVN_MIRROR
>
> Now the actual conversion:
>
>     % mkdir myworkspace
>     % cd myworkspace
>     % git svn init file://$SVN_MIRROR/allegro \
>         --rewrite-root=https://alleg.svn.sourceforge.net/svnroot/alleg \
>         --trunk=trunk --branches=branches --tags=tags
>     % git config svn.authorsfile /path/to/authors.txt
>     % git svn fetch
>
> The last step takes a long time.  Once it's done, just for kicks, check
> the size of the git repository.  Remember what it was before?
>
>     % du -sh .git
>     25M .git
>
> Yup.
>

Ah, thanks for all that :) I almost had the entire 4.9 branch converted last 
night, but then I ran out of disk space ::) too many iso images and such.

I think the wiki will get a copy of this info in short order :)


-- 
Thomas Fjellstrom
tfjellstrom@xxxxxxxxxx