Looking at Win32, it scans the whole directory periodically, right? I must miss something, but how can that be called efficient?
A proper benchmarking program is in the works, however manual testing does show only minimal resource usage.
For more, see this issue: https://github.com/e-dant/watcher/issues/10
The current solution isn’t ideal, and is being addressed here: https://github.com/e-dant/watcher/issues/10