Bazaar

Bazaar

 




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Differences between revisions 65 and 67 (spanning 2 versions)
Revision 65 as of 2006-07-18 20:31:50
Size: 7253
Comment: Add note about resource usage.
Revision 67 as of 2006-07-20 21:25:46
Size: 7785
Comment: Add links to example branches.
Deletions are marked like this. Additions are marked like this.
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= Introduction =
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.
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= Introduction = 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.
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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.

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
alpha. Its resource requirements are also quite heavy at the moment, but work is under way to improve that.
It is fully functional, but has only been tested on a few different Subversion branches (samba, wireshark, subversion, cups), so should be considered alpha.
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 * [http://samba.org/~jelmer/bzr/bzr-push-samba.png push 2]

= Example branches =
All created by simply running {{bzr branch ORIGINAL-URL}}. * [http://people.samba.org/bzr/jelmer/samba/3.0 Samba 3] - Original at svn://svn.samba.org/samba/branches/SAMBA_3_0[http://people.samba.org/bzr/jelmer/samba/3.0 ]
 * [http://people.samba.org/bzr/jelmer/samba/4.0 Samba 4] - Original at svn://svn.samba.org/samba/branches/SAMBA_4_0
 * [http://people.samba.org/bzr/jelmer/samba/docs Samba docs] - Original at svn://svn.samba.org/samba-docs/trunk
 * [http://people.samba.org/bzr/jelmer/svn/trunk Subversion trunk] - Original at svn+http://svn.collab.net/repos/svn
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 * Subversion working copies. Can be modified, queried (`bzr status' on a vanilla working copied created with `svn co' works) and committed from.   * Subversion working copies. Can be modified, queried ({{{bzr status' on a vanilla working copied created with }}}svn co' works) and committed from.
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 * Handles complex operations in Subversion: committing to two branches at once, upgrading directories to branches, 
   copies from early revisions, ...
 * Handles complex operations in Subversion: committing to two branches at once, upgrading directories to branches,
  . copies from early revisions, ...
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 * 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.
 * 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.
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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.

  
This might require also storing 'bzr:inventory' and 'bzr:revision' properties in order to make
  
sure the sha1's for a revision keep matching.
  . 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. This might require also storing 'bzr:inventory' and 'bzr:revision' properties in order to make sure the sha1's for a revision keep matching.
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 * Proper Windows support. Most of the code depends on '/' being the path separator at the moment.   * Proper Windows support. Most of the code depends on '/' being the path separator at the moment.
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  * More efficient use of disk space and CPUs
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    * More efficient use of disk space and CPUs   * Override implementation of get_revision_delta(). Will speed up 'bzr log -v'
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    * Override implementation of get_revision_delta(). Will speed up 'bzr log -v'   * use svn_ra_replay() on systems that have Subversion 1.4. Saves a couple of roundtrips when fetching history. Initial work in branch at http://people.samba.org/bzr/jelmer/bzr-svn/replay
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    * use svn_ra_replay() on systems that have Subversion 1.4. Saves a couple of roundtrips when fetching history. Initial work in branch at http://people.samba.org/bzr/jelmer/bzr-svn/replay

  
* implement svn_ra_get_dir_revs() in Subversion to fetch the properties set on a specific directory all at once.
  * implement svn_ra_get_dir_revs() in Subversion to fetch the properties set on a specific directory all at once.
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Spec at https://launchpad.net/products/bzr/+spec/filecopies
  . Spec at https://launchpad.net/products/bzr/+spec/filecopies
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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]. 
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].
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Simply place this directory in ~/.bazaar/plugins and you should be able
to check out branches from Subversion using bzr.
Simply place this directory in ~/.bazaar/plugins and you should be able to check out branches from Subversion using bzr.
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Please file bug reports in launchpad. The product URL for bzr-svn is https://launchpad.net/products/bzr-svn/. 
Please file bug reports in launchpad. The product URL for bzr-svn is https://launchpad.net/products/bzr-svn/.
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TableOfContents(2)

Introduction

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.

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 (samba, wireshark, subversion, cups), so should be considered alpha.

Screenshots

Example branches

All created by simply running bzr branch ORIGINAL-URL. * [http://people.samba.org/bzr/jelmer/samba/3.0 Samba 3] - Original at svn://svn.samba.org/samba/branches/SAMBA_3_0[http://people.samba.org/bzr/jelmer/samba/3.0 ]

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.
  • Handles complex operations in Subversion: committing to two branches at once, upgrading directories to branches,
    • copies from early revisions, ...

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
  • "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. This might require also storing 'bzr:inventory' and 'bzr:revision' properties in order to make sure the sha1's for a revision keep matching.
  • Proper read locking, which has basically been ignored for now.
  • Proper Windows support. Most of the code depends on '/' being the path separator at the moment.
  • Performance. Network-wise (both bandwidth and roundtrips), the plugin is in good shape. However, it is currently quite CPU-intensive for no good reason and I hope to make a couple of improvements in that area.
    • More efficient use of disk space and CPUs
    • Override implementation of get_revision_delta(). Will speed up 'bzr log -v'
    • use svn_ra_replay() on systems that have Subversion 1.4. Saves a couple of roundtrips when fetching history. Initial work in branch at http://people.samba.org/bzr/jelmer/bzr-svn/replay

    • implement svn_ra_get_dir_revs() in Subversion to fetch the properties set on a specific directory all at once.
  • Creating native Subversion working copies. This would mostly be supported for completeness' sake, 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:

Other features currently held back by Bazaars feature set:

  • 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. Subversion supports horizon history fine.
  • Tracking copies.

Features held back by Subversion:

Implementation

http://people.samba.org/bzr/jelmer/bzr-svn/bzr.dev

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].

A patch against Subversion 1.3.2 is also available at http://people.samba.org/bzr/jelmer/subversion-1.3.2-pythonfixes.diff. To build Subversions' Python bindings, run:

$ tar xvfj subversion-1.3.2.tar.bz2
$ cd subversion-1.3.2
$ ./autogen.sh --release
$ ./configure
$ make
$ make check-swig-py
$ sudo make install install-swig-py

You will also need bzr.dev plus the fixes from the following branches if you would like to use lightweight checkouts:

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'