You might want to have a look at Apache2::UploadProgress. It requires that you run mode_perl2, but it makes things a whole lot easier than what you have. In fact, you don't have to make any changes to your code to use it. You just have to load a couple of JavaScript files in your HTML page, and then add an onSubmit handler to the form and you are done.

All the magic is done with an apache filter, so your code doesn't even have to know that you are using an upload meter on the frontend.

I gave a demo of this at YAPC in Chicago and I have put my example code online, including the upload meter example.