Preventing Undo For a Specific Layer.

Thanks a lot people. I guess erasing the history states might not be a valid option in my case. I'll be handling undo through Generator-core now. 

My thoughts are the same as JJ"s about removing history states, but I have a feeling that you're using them in your script, otherwise the undo and redo might not be a problem.

The only way I can think you could do that is to clear current history states and snapshots  stepping back to any history state or snapshot will revert all layers to the state they had when the snapshot or history was created.  To delete snapshots you may need to do a save, close and then reopen the document. Which will create new history with an open snapshot and a open state in the history.  All unsaved changes would also have been commited. There will be nothing to undo or redo. All layers will be committed.

I'm not really sure. Wouldn't putting a lock on the layer work? You should be able to disable it or enable it via scripting. What exactly are you trying to do or avoid?