Improve performance

[An-dz]

localStorage is not needed in this extension, creating an object in root level is enough and much faster.

[Christoph142]

Global variables are always a bad idea. It could possibly conflict with foreign code.
Did you measure of what magnitude the performance gain is to justify this?

[An-dz]

I've just measured on your extension and the difference is negligible, no changes. On my extension I had better performances because I use it for more data.

Anyway, there's no problem creating a global variable, this is the background page, it does not conflict with foreign code because foreign code never runs on it and the background never runs on foreign code. This is just a problem with userScripts.

And if you still want to use it I recommend changing to sessionStorage, this way you can remove localStorage.clear()