Chrome Extension webRequest synchronous behavior for async calls

Question

I've created a test web server that I'm using to act as a 'web filter' of sorts. I'm trying to create an extension that uses the webRequest API to make sure that my web server allows or blocks all incoming URL's.

To do this, I'm making an AJAX call from within webRequest to my web server and I'd like to use the response to determine whether to block or allow the specified URL. The problem is, the webRequest method is async, and AJAX calls are async, so I can't wait reliably wait for a response from my server.

I also can't store all blocked / allowed URL's in localStorage, because there could potentially be hundreds of thousands. I've tried using jQuery's async: false property in it's ajax implementation, but that makes the browser almost completely unusable when hundreds of requests are happening at the same time. Anyone have any ideas as to how I might be able to work around this?

EDIT : I know similar questions to this have been asked before, but there haven't been any viable solutions to this problem that I've seen.

Answer 1

I see only two good choices:

1. make that site a webproxy
2. use unlimitedStorage permission and store the urls in WebSQL database (it's also the fastest). Despite the general concern that it may be deprecated in Chrome after W3C stopped developing the specification in favor of IndexedDB I don't think it'll happen any time soon because all the other available storage options are either [much] slower or less functional.