Today, I setup a Subversion development environment for the first time in ... more years than I can recall. I can confirm that the test suite passes with this patch, and that the patch itself makes sense to me. I also used it for my own svnsync activity (I do nightly backups of personal repositories), and it seems to work as advertised.
Not gonna lie, I feel too "out of the game" to commit this patch outright. But, I *am* comfortable giving a +1 on it, for whatever that nuance might mean. -- Mike On Sat, Jan 31, 2026 at 2:48 PM Timofei Zhakov <[email protected]> wrote: > On Thu, Jan 29, 2026 at 10:47 PM Jordan Peck via dev < > [email protected]> wrote: > >> Hi all, >> >> I'd like to propose a patch that optimises svnsync when synchronizing to >> local filesystem repositories (file:// URLs). Currently, svnsync performs >> a two-step process for each revision: >> >> 1. Commit the revision content (author/date are set to the current >> user and current time) >> 2. Update svn:author and svn:date revision properties to match the >> source repository >> >> This works but is inefficient for file:// URLs where we have direct >> repository access and can set these properties correctly during the >> initial commit. >> >> >> THE PROBLEM >> ----------- >> >> When svnsync replays a revision from a source repository, the commit >> is created with the local user as the author and the current time as >> the date. After the commit completes, svnsync then makes separate >> svn_ra_change_rev_prop2() calls to update svn:author and svn:date to >> match the source repository. >> >> For remote servers (svn://, http://), this two-step process is necessary >> because the server enforces its own author/date policies. However, for >> file:// URLs via ra_local, we have direct access to the repository and >> can bypass this limitation. >> >> We have an SVN server acting as the slave via the Apache module proxy, >> the slave server is kept in sync with the master using svnsync. This >> two-step approach has caused issues with various tools that monitor the >> slave SVN server for new revisions, they will occasionally get the data >> for a synced revision that hasn't yet had the revision properties >> copied. Having the sync be a single atomic operation means this can >> never happen. >> >> >> THE SOLUTION >> ------------ >> >> This patch introduces a new RA capability "commit-allow-rev-props" that >> ra_local advertises. When svnsync detects this capability on the >> destination repository, it: >> >> 1. Includes svn:author and svn:date in the initial commit's revprop >> table (instead of filtering them out) >> >> 2. ra_local now conditionally preserves these properties: >> - svn:author is only set to the session user if not already provided >> - If svn:date is provided, the SVN_FS_TXN_CLIENT_DATE flag is passed >> to svn_fs_begin_txn2() so the filesystem uses that date >> >> 3. Skips the post-commit revprop update step since author/date are >> already correct >> >> >> CHANGES OVERVIEW >> ---------------- >> >> subversion/include/svn_ra.h: >> - Added SVN_RA_CAPABILITY_COMMIT_ALLOW_REV_PROPS capability definition >> >> subversion/include/svn_repos.h: >> - Added svn_repos_fs_begin_txn_for_commit3() with flags parameter >> - Added svn_repos_get_commit_editor6() with txn_flags parameter >> >> subversion/libsvn_repos/fs-wrap.c: >> - Implemented svn_repos_fs_begin_txn_for_commit3() which passes flags >> (including SVN_FS_TXN_CLIENT_DATE) to svn_fs_begin_txn2() >> >> subversion/libsvn_repos/commit.c: >> - Added txn_flags to edit_baton structure >> - Implemented svn_repos_get_commit_editor6() to support txn_flags >> - Updated open_root() to use the new begin_txn function >> >> subversion/libsvn_ra_local/ra_plugin.c: >> - Advertises SVN_RA_CAPABILITY_COMMIT_ALLOW_REV_PROPS >> - Modified get_commit_editor to preserve caller-provided author/date >> - Sets SVN_FS_TXN_CLIENT_DATE when date is provided in revprops >> >> subversion/svnsync/svnsync.c: >> - Detects the new capability on the destination >> - When capability is present, includes author/date in commit revprops >> - Skips post-commit revprop sync when capability is present >> - Updated user-facing messages to reflect the optimization >> >> >> USER-VISIBLE CHANGES >> -------------------- >> >> When synchronizing to a file:// URL, svnsync now displays: >> >> Destination supports commit-time author and date; no post-commit >> revprop sync needed. >> Committed revision 1. >> Committed revision 2. >> ... >> >> Instead of the previous: >> >> Committed revision 1. >> Copied properties for revision 1. >> Committed revision 2. >> Copied properties for revision 2. >> ... >> >> >> BENEFITS >> -------- >> >> 1. Atomicity: Author and date are set in the same transaction as the >> commit, rather than being updated afterward. >> >> 2. No behavioral change for remote servers: The optimization only >> applies when the destination advertises the capability, so svn:// >> and http:// synchronization continues to work as before. >> >> 3. Reduced I/O: Eliminates separate revprop change operations for each >> revision synced to a file:// destination. >> >> COMPATIBILITY >> ------------- >> >> - The new capability is only advertised by ra_local, so this is a >> client-side optimization with no server protocol changes. >> >> - Existing svnsync mirrors continue to work unchanged. >> >> - The new API functions (svn_repos_fs_begin_txn_for_commit3 and >> svn_repos_get_commit_editor6) maintain backward compatibility >> through wrapper functions. >> >> >> TESTING >> ------- >> >> I have tested this with svnsync to file:// URLs and verified that: >> - Revision properties (author, date, log) match the source repository >> - The new optimization message appears at sync start >> - No "Copied properties" messages appear >> - Subsequent incremental syncs work correctly >> >> >> Please review and let me know if you have any questions or suggestions. >> >> Thanks, >> Jordan Peck >> > > Hi, > > +1 > > I didn't look into the patch in detail, but the idea sounds good to me. > > -- > Timofei Zhakov >
