3 This directory contains a simple plugin that adds
4 Subversion (http://subversion.tigris.org/) branch support to
5 Bazaar (http://www.bazaar-vcs.org/)
9 You will need at least version 0.9 of Bazaar-NG (currently unreleased).
11 You also need a fairly recent version of the Python bindings to the
12 Subversion libraries. At the moment, the svn plugin only works with
13 Subversion 1.5 (trunk). I plan to submit patches against the python-subversion
14 package in Ubuntu Edgy later.
18 The following features are currently present:
20 * Connecting to remote Subversion repositories over all
21 protocols supported by Subversion itself (at present:
22 svn://, svn+ssh://, http:// (webdav), file://)
23 as well as dump files.
25 Checkouts, lightweight checkouts and branching works.
27 * Track Bazaar merges in Subversion. Merged revisions show up
30 * Subversion working copies. Can be modified, queried
31 (`bzr status' on a vanilla working copied created with
32 `svn co' works) and committed from.
34 * Committing to Subversion from Bazaar.
36 * Push Bazaar revisions to Subversion. These revisions will
37 show up in Subversion as a commit with the pushed revision
38 as one of the parents.
40 * Follow branch copies. Revision history is not
41 truncated when a branch was copied in Subversion.
43 * Efficiently uses network bandwidth.
45 * Recognizes file metadata (executable bits, symlinks).
47 * 'import-svn' command with functionality similar to svn2bzr.
49 * Ability to track merges done with SVK (http://svk.elixus.org/)
52 * Generates consistent file ids and revision ids. Two branches made using
53 this plugin of the same Subversion branch will result in *exactly* the same
56 * Handles complex operations in Subversion: committing to two branches at
57 once, upgrading directories to branches, copies from early revisions, ...
59 == Future Enhancements ==
61 In the future, I also hope to support:
63 * Renames. Initial work has been done to support this,
64 but the number of corner cases is wide, so support for this
65 has not been enabled by default yet.
67 Those brave enough can test the current support out by
68 registering SvnRenamingRepository instead of
69 SvnRepository in __init__.py.
71 * "True" push. This requires storing the Bazaar
72 inventory and revision in Subversion revision properties.
74 Ideally, revision id aliases would have to be used so the
75 revision id that is being 'overriden' can still exist.
77 Once this is implemented, it would also be possible and
78 make sense to store GPG signatures for commits in
81 This might require also storing 'bzr:inventory' and 'bzr:revision'
82 properties in order to make sure the sha1's for a revision keep matching.
84 * Proper read locking, which has basically been ignored for now.
86 * Performance. Network-wise (both bandwidth and roundtrips), the plugin is in
87 good shape. However, it is currently quite CPU-intensive for no good reason
88 and I hope to make a couple of improvements in that area.
90 * Keep on-disk cache of file-ids to path mappings
92 * Override implementation of get_revision_delta(). Will speed up 'bzr log -v'
94 * use svn_ra_replay() on systems that have Subversion 1.4. Saves a couple of roundtrips when fetching history.
96 * implement svn_ra_get_dir_revs() in Subversion to fetch the properties set on a specific directory all at once.
98 * Creating native Subversion working copies. This
99 would mostly be supported for completeness' sake, there are not
100 a lot of advantages in supporting it.
102 Some Subversion properties can currently not be represented in Bazaar
103 and are therefore ignored for the time being:
105 * `svn:ignore' is not imported. There should be a
106 `Repository.get_ignores(revid)' call in Bazaar rather than a magic
109 * `svn:externals'. Externals should be mapped to Bazaar 'by-reference'
110 nested branches and the other way around. This can't be implemented
111 this until Bazaars nested branch support lands. AaronBentley's work
112 in progress is at http://code.aaronbentley.com/bzr/bzrrepo/nested-trees/.
113 This has been delayed until after 0.9 because of required repository
116 Other features currently held back by Bazaars feature set:
118 * Horizon revision history. Most of the existing Subversion repositories
119 are quite large and it would therefore be nice to be able to limit
120 the amount of history that needs to be retrieved during checkouts.
122 Features held back by Subversion:
124 * Showing SVN merges as merges in Bazaar. This requires full merge tracking
125 information in Subversion, something which the Subversion folks are working
126 on at the moment (see https://svn.collab.net/repos/svn/branches/merge-tracking).
128 Might require cherry-picking support in Bazaar (or at least the ability
129 to know about cherry picks)
133 Please file bug reports in launchpad. The product URL for bzr-svn is
134 https://launchpad.net/products/bzr-svn/. The wiki for this
135 plugin is at http://bazaar-vcs.org/BzrSvn.
139 Simply place this directory in ~/.bazaar/plugins and you should be able
140 to check out branches from Subversion using bzr.
144 GNU General Public License, v2 or later.
148 Simply run 'bzr selftest svn'
152 Jelmer Vernooij <jelmer@samba.org>