On Fri, 2009-12-04, Julian Foad wrote: > I don't expect anyone to review the whole of this, but any comments > would be welcome. It's about time I posted what I'm up to. It's not a > "finished" patch, by any stretch of the imagination, so please don't > commit it.
I fixed up a load of this and committed it in r889320. > Concerns/unfinished business: > > - Should I be using the DAG layer to do these manipulations? Are there > DAG functions that already do such duplication, or part of it? I > found some that were useful, but don't understand what the > significant difference is between the DAG layer and other levels. > (I did read the description in <> section "".) Not resolved, but I think the right direction is to call dag-layer functions from revs-txns, and for the dag-layer functions to call down further. For now, I have put my helper functions in a separate file subversion/libsvn_fs_base/obliterate.[ch]. > - All the "dup" functions could take the old-txn-id as a parameter, and > only change txn-ids that match it. If there are any txn-id fields that > refer to the current txn in some cases but not in other cases, then > we need this, and need to compare with the old-txn-id to decide whether > to change it. Are there any such cases? I think it's correct as is. > - I don't know whether I should change the copy-ids. I don't think I > should, because future revs refer to them, but I can't dup the copies > table rows in the same way unless I give them new copy-ids. If > necessary, I could possibly dup them to new ids and then translate > the new ids back to the old ones at "commit-obliteration" time. Decided I should not change any copy-ids, and should just update the existing entries in the copies table at oblit-commit time. Not done yet. > - In a normal txn, are the "changes" rows used and updated during txn > building, or only filled in at commit time? If the former, I need to > dup them at begin-obliteration-txn time; if the latter, at > commit-obliteration-txn time. I think the latter, and added comments to that effect. > - In "rep_dup()", when I dup a child rep in a "rep window" (or "delta > chunk"), I need to set an "offset" field. I expect there's a > function I should be using to ensure that gets set correctly. Not resolved. - Julian
