Could you give me an example of URL rewriting helper for appcache?

Hi.

I am using appcache package for faster load.
I put images in public folder, and use them in CSS or ajax.
Appcache certainly loads these files in application cache, but a browser does not use application cache and accesses a server for these files and the server returns 304 status code for each of them.
It makes load speed slower.

How can I improve it?

I read meteor’s source code of appcache and I understood my problem .
I need URL rewriting helper.

Here is a comment from source code.

// This means requests for the bare url (/image.png instead of
// /image.png?hash) will work offline. Online, however, the browser
// will send a request to the server. Users can remove this extra
// request to the server and have the asset served from cache by
// specifying the full URL with hash in their code (manually, with
// some sort of URL rewriting helper)

My next question is, how can I get resource.hash for each images and write it in CSS?