[Zope] multipart pushing

Howdy Zopistas! I'd like to implement a chat function using the multipart content type and I wonder if that is possible with Zope. My idea is to write a python script that pushes the content of a database until e.g. the stop button is pressed in the Browser. But how would the script know that it's supposed to stop? And would such a longtime connection completely occupy one Zope thread so that I'd have to increase the number of threads? Ragnar