FileSystemWatcher runs too slow on Unity Editor

Unity Engine
,
1

Hi, I’m trying to create my own file change monitoring system using FileSystemWatcher.
But the watcher performance is too bad for practical use.

Background

  • I have additional codegen / datagen apps outside the Unity Editor.

  • When they run, they write a lot of files inside Unity Assets folder.

  • If Unity ‘Auto Refresh’ option is enabled, the two processes can interfere and unwanted result may occur.

  • So I need to disable the ‘Auto Refresh’ option, and refresh Asset import manually.(AssetDatabase.Refresh())

  • I want to notify users with GUI when file change is detected.

  • I decided to make a watcher using FileSystemWatcher

  • A class with InitializeOnLoadAttribute creates and holds the watcher instance.

Status

  • The watcher class runs fine when built as a console app.

  • File change events are picked up immediately.

  • The same class runs extremely slow when run in Unity Editor.

  • It took more than 5 seconds to get the change event.

Debug

  • Create Watcher instance on a background thread(Task.Factory.StartNew())

  • Still too slow.

  • According to the sourcecode, FileSystemWatcher uses Threadpool internally. So the watcher is running on a background thread already.

Question

  • I want to know why the watcher run slow when in Unity Editor. What makes it differ from console?
  • What is the proper way to implement my own file watcher in Unity?
1 Like
2

got very similar issue. file system watcher on big directories (with recursion) - is quite slow and causes performance spikes