Tracking The Size of an Index

[Jerry Camel]

I have a scenario where I need to create DVD sized collections of documents 
along with an index.  Is it possible to track the size of an index while 
you're adding to it?

Basic scenario is to loop through all docs, adding each to an index.
After each add, verify the total size of all data plus index files to see if 
it's time to close this index and move on to the next Disc.

Thoughts?

Thanks.

J