Over Christmas, I'm working on making the assistant support direct mode. I like to have a fairly detailed plan before starting this kind of job, but in this case, I don't. (Also I have a cold so planning? Meh.) This is a process of seeing what's broken in direct mode and fixing it. I don't know if it'll be easy or hard. Let's find out..

• First, got direct mode adding of new files working. This was not hard, all the pieces I needed were there. For now, it uses the same method as in indirect mode to make sure nothing can modify the file while it's being added.

• An unexpected problem is that in its startup scan, the assistant runs git add --update to detect and stage any deletions that happened while it was not running. But in direct mode that also stages the full file contents, so can't be used. Had to switch to using git plumbing to only stage deleted files. Happily this also led to fixing a bug; deletions were not always committed at startup when using the old method; with the new method it can tell when there are deletions and trigger a commit.

• Next, got it to commit when direct mode files are modified. The Watcher thread gets a inotify event when this happens, so that was easy. (Although in doing that I had to disable a guard in direct mode that made annexed files co-exist with regular in-git files, so such mixed repositories probably won't work in direct mode yet.)

  However, naughty kqueue is another story, there are no kqueue events for file modifications. So this won't work on OSX or the BSDs yet. I tried setting some more kqueue flags in hope that one would make such events appear, but no luck. Seems I will need to find some other method to detect file modifications, possibly an OSX-specific API.

• Another unexpected problem: When an assistant receives new files from one of its remotes, in direct mode it still sets up symlinks to the content. This was because the Merger thread didn't use the sync command's direct mode aware merge code.. so fixed that.

• Finally there was some direct mode bookeeping the assistant has to get right. For example, when a file is modified, the old object has to be looked up, and be marked as not locally present any longer. That lookup relies on the already running git cat-file --batch, so it's not as fast as it could be, if I kept a local cache of the mapping between files and objects. But it seems fast enough for now.

At this point the assistant seems to work in direct mode on Linux! Needs more testing..