[rfc] bzr-colo into core

[Martin Pool]

On 24 March 2011 20:16, Martin Geisler <mg at aragost.com> wrote:
> Martin Pool <mbp at canonical.com> writes:
>
>> {summary}
>>
>> Let's make bzr-colo the default model for bzr 3.0 in September.
>>
>>
>> {the problem}
>>
>> At the moment there are various different ways to use bzr: checkouts
>> from a separate repository directory; bzr-colo; checkouts with local
>> commits; standalone branches. This gives users some flexibility but it
>> also makes some things confusing, and it's easy for people to end up
>> with a setup that's quirky, or that doesn't work well for them.
>
> This might be totally irrelevant for your discussion, but as a Mercurial
> developer, I was wondering if you have looked at how Mercurial supports
> multiple branches in a single repository?

Hi, Martin (there's a lot of us around),

I have looked a bit at how Mercurial does it. Thanks for explaining it.

The repository and branch breakdown is fairly similar; bzr too has a
DAG that is pointed to by branch tips.  One difference is that I
believe hg generally hardlinks repository-internal files when you make
new repositories on the same disk, whereas bzr copies, and rather
wants to avoid having multiple repositories unless you really want
them to be separate.

The situation you describe there is pretty much what bzr-colo gives
you.  The main issue that comes out of this thread seems to be that
people like having multiple working trees all addressing branches
within the same repository: either creating and deleting those trees
as needed, or switching a small number of trees among several
branches.

I guess in hg you would do this by having a repository for each
interesting tree, and pushing/pulling between them?


Martin