Compaction state written even if not used

[arj03]

I was checking out the latest db2 changes in the browser and things are not working because the compaction module has a few things that needs fixing before it can. The first is stateFileExists() because it uses fs directly. I was working around that, it requires the function to be async, but that seems to be okay. Then I ran into another problem with writeUInt32LE not being available (callstack is save() & stop()). This seems to be because browserify is using an old version of the buffer module. In any case, I was wondering why it was even try to write this file in the first place. I havn't used the API, so I didn't expect this to do anything. Maybe it would be good to change so doesn't write the file if the file doesn't exist in the first place? Just checking my assumptions about this before making changes :)

[staltz]

Yes, agreed! About StateFileExists being called at the beginning, it's currently important that it's sync, to prevent race conditions. It's fine if you change it to be async, just be careful about the race conditions (i.e. ssb-db2 compaction-related code running before StateFileExists in AAOL would be a problem).