← Revision 254 as of 2013-05-24 18:21:05
Just provide link to homepage, now restructuredtext support on the wiki is broken
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|= Introduction =||= Bazaar support for Subversion branches, working trees and repositories =|
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|This plugin provides a mapping between Bazaar and Subversion
revisions unambiguous so to people that run Bazaar on a Subversion branch end
up with exactly the same branch and can pull changes from each other.
|bzr-svn is a plugin that allows Bazaar direct access to Subversion
repositories. It allows most bzr commands to work directly against Subversion
repositories, as if you were using bzr with a native bzr repository.
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|The plugin can at the moment be used to commit to, pull from, merge from, push to and view logs of
Subversion branches from Bazaar.
It is fully functional, _BUT_ has only been tested on a few different Subversion branches, so should be considered
== Screenshots ==
* [http://samba.org/~jelmer/bzrk-svn.png bzrk 1]
* [http://samba.org/~jelmer/bzr/bzrsvn-merge.png bzrk 2]
* [http://samba.org/~jelmer/bzr/bzrsvn-renames.png renames]
* [http://samba.org/~jelmer/bzr/bzrsvn-commit.png commits]
* [http://samba.org/~jelmer/bzr/bzr-push-to-svn.png push]
== Features ==
The following features are currently present:
* Connecting to remote Subversion repositories over all protocols supported by Subversion itself (at present: svn://, svn+ssh://, http:// (webdav), file://) as well as dump files. Checkouts, lightweight checkouts and branching works.
* Track Bazaar merges in Subversion. Merged revisions show up as ghosts.
* Subversion working copies. Can be modified, queried (`bzr status' on a vanilla working copied created with `svn co' works) and committed from.
* Committing to Subversion from Bazaar.
* Push Bazaar revisions to Subversion. These revisions will show up in Subversion as a commit with the pushed revision as one of the parents.
* Follow branch copies. Revision history is not truncated when a branch was copied in Subversion.
* Efficiently uses network bandwidth.
* Recognizes file metadata (executable bits, symlinks).
* 'import-svn' command with functionality similar to svn2bzr.
* Ability to track merges done with SVK (http://svk.elixus.org/) and write merges from SVK/Svn branches in a format understandable by SVK.
* Generates consistent file ids and revision ids. Two branches made using this plugin of the same Subversion branch will result in *exactly* the same Bazaar branch.
== Future Enhancements ==
In the future, I also hope to support:
* Renames. Initial work has been done to support this, but the number of corner cases is wide, so support for this
has not been enabled by default yet.
Those brave enough can test the current support out by registering SvnRenamingRepository instead of SvnRepository in __init__.py.
* "True" push. This requires storing the Bazaar inventory and revision in Subversion revision properties.
Ideally, revision id aliases would have to be used so the revision id that is being 'overriden' can still exist.
Once this is implemented, it would also be possible and make sense to store GPG signatures for commits in Subversion branches.
* Proper read locking, which has basically been ignored for now.
* Performance. Network-wise (both bandwidth and roundtrips), the plugin is currently pretty much as efficient as it can be. However, it is currently quite CPU-intensive for no good reason and I hope to make a couple of improvements in that area.
* Creating and updating native Subversion working copies. This would mostly be supported for completeness, there are not a lot of advantages in supporting it.
Some Subversion properties can currently not be represented in Bazaar and are therefore ignored for the time being:
* `svn:ignore' is not imported. There should be a `Repository.get_ignores(revid)' call in Bazaar rather than a magic '.bzrignore' file.
* `svn:externals'. Externals should be mapped to Bazaar 'by-reference' nested branches and the other way around. This can't be implemented until Bazaars nested branch support lands. AaronBentley's work in progress is at http://code.aaronbentley.com/bzr/bzrrepo/nested-trees/.
Other features currently held back by Bazaars feature set:
* Showing SVN merges as merges in Bazaar. This requires support for partial merges in Bazaar. Another option would be storing full merge information in Subversion, something which the Subversion folks are working on at the moment (see https://svn.collab.net/repos/svn/branches/merge-tracking).
* Branch.revision_history() and generating file ids currently requires retrieving the full `log' of a Subversion repository.
It might be possible to get rid of the need to retrieve the full log if Bazaar supported file id aliases and if Branch.revision_history() would use iterators.
The log output can be cached though and only takes a few minutes on large repositories anyway.
(needs more thought)
* Horizon revision history. Most of the existing Subversion repositories are quite large and it would therefore be nice to be able to limit the amount of history that needs to be retrieved during checkouts.
== Implementation ==
== Installation ==
The plugin requires a couple of fixes to the Python bindings for Subversion. Debian/Ubuntu packages available at http://samba.org/~jelmer/bzr/. You need the python-subversion and
libsvn0 packages. These changes have been submitted to the Ubuntu Subversion package in [https://launchpad.net/products/bzr-svn/+bug/51304 #51304].
You will also need bzr.dev (plus a small fix for workingtrees that I will send in soon).
Simply place this directory in ~/.bazaar/plugins and you should be able
to check out branches from Subversion using bzr.
== Bugs ==
Please file bug reports in launchpad. The product URL for bzr-svn is https://launchpad.net/products/bzr-svn/.
== License ==
GNU General Public License, v2 or later.
== Unit testing ==
Simply run 'bzr selftest svn'
Bazaar support for Subversion branches, working trees and repositories
bzr-svn is a plugin that allows Bazaar direct access to Subversion repositories. It allows most bzr commands to work directly against Subversion repositories, as if you were using bzr with a native bzr repository.