nested trees design-approach : composite trees vs iter_changes

[Aaron Bentley]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Martin Pool wrote:
> For those following along at home, the underlying design is described in
> 
>  http://bazaar-vcs.org/NestedTreesDesign
>  http://bazaar-vcs.org/NestedTreeSupport
> 
> Is there something else I've missed.
> 
> I see Aaron was editing the design document up til April.  I'm not
> sure if it's totally up to date with that document.

I can't see anything out-of-step with the patch in
http://bazaar-vcs.org/NestedTreesDesign.

http://bazaar-vcs.org/NestedTreeSupport dates back to UBZ and doesn't
reflect my current design.

> I would have liked to see this patch include a description of
> CompositeTrees to go into the developer guide or overview for a couple
> of reasons.  Firstly, if it's going to be a major new concept
> documenting it will help people coming into the bzr code later on to
> understand it.

I'm not sure that it's going to be a major new concept.  It's meant as a
helper for a few commands.

> Secondly and more importantly here, it'll let us
> discuss the conceptual side of the patch at a higher level than the
> code, knowing the documentation is in sync with what's coming in
> through the patch.
> 
> For instance, that document says
> 
>  > The root-ids of trees must be unique, so that the same file-id can
> be used in both the containing tree and the subtree, to simplify
> access within trees.
> 
> which seems to be at odds with this thread saying that common file-ids
> aren't allowed across trees.

Perhaps it would be better to say that the same file-id may not be used
to refer to multiple things across trees.  The tree reference in the
containing tree and the root directory in the subtree share a file id
because they both refer to the same directory.

> I don't mean to beat up on that document
> or its author/s and maybe the point didn't seem important before, but
> it does seem like something better handled in documentation than in
> patches.

Though that documentation should then be submitted as a patch ;-) ?

Okay, I'll resubmit the composite trees patch with some added documentation.

> Is the overall work in a public branch somewhere we could see the
> whole thing, rather than just the individual patches?  I don't see one
> in <https://code.edge.launchpad.net/bzr>

The closest thing is this: lp:~abentley/bzr/nested-trees

However, it does not include
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C49F22B67.8020703%40aaronbentley.com%3E
or my work on nested pull.  I keep multiple branches in flight, so that
when one branch is awaiting review, I can keep working on others.

Aaron
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkoBp60ACgkQ0F+nu1YWqI19xACfURPPEAgZr40tKiyeMvEDcSVj
leQAn0wK1ylZfdsccM4Q85E0oXRF//V5
=S9Aw
-----END PGP SIGNATURE-----