Ask HN: How can I find HN posts by URL?

I plan to build a Firefox extension that will find HN posts for the URL I'm currently viewing.

Something similar to: https://github.com/powerpak/hn-sidebar. http://tedpak.com/2013/03/20/hacker-news-sidebar-a-chrome-extension.

The way this extension does this currently is by using the Algolia API's query method and filtering out results that have the same url.

https://github.com/powerpak/hn-sidebar/blob/master/script.js

Is there a better way of doing this?