Providing an embedded webkit with resources from memory

I'm working on an application that embeds WebKit (via the Gtk bindings). I'm trying to add support for viewing CHM documents (Microsoft's bundled HTML format).

HTML files in such documents have links to images, CSS etc. of the form "/blah.gif" or "/layout.css" and I need to catch these to provide the actual data. I understand how to hook into the "resource开发者_开发问答-request-starting" signal and one option would be to unpack parts of the document to temporary files and change the uri at this point to point at these files.

What I'd like to do, however, is provide WebKit with the relevant chunk of memory. As far as I can see, you can't do this by catching resource-request-starting, but maybe there's another way to hook in?

An alternative is to base64-encode the image into a data: URI. It's not exactly better than using a temporary file, but it may be simpler to code.