JigSaw in proxy, help with filters !!!

Hello all,

Sorry to disturb you again. I hope that by describing my project, someone would be able to help me.

I am using JigSaw 2.0.2 proxy package http://www.w3.org/Jigsaw/jigsaw_proxy_2.0.2.tar.gz

I would like to add some functionnality to my proxy for an e-learning tool. I suppose the best way to do this is to add a filter to the proxy. Here is what I would like to do:

I would like to retrieve all GET requests from the client with the following information:

1) The time when it has been invoked
2) Where it is stores in the cache
3) Whether this is a request from the teacher or not.

Assume that the teacher browse http://www.site.com/Slide1.html at 00.00am, Then it browse http://www.site.com/Slide2.html at 00.02a.m. At 00.04a.m. its stops our tool which is connected to the JigSaw proxy.

The purpose is to create an index file that says: during 2min, the teacher has seen this file, then this file during 2min then end of the session.

Slide1.html has slide1.gif and Slide2.html has slide2.gif

In my filter,

1) How can I differentaite the Slide1.html GET from the slide1.gif  (these two entites are only one "slide") ? In the old version, I am basing on the referer HTTP header but it does not work all the time
2) How can I get the file that has been requested (at the end, the tool produce a ZIP file with all the files that have been seen during the session, that is slideX.gif ans SlideX.html). I was wondering about the cache or the getStream ...

Please help !