threads, file access and stuff

[Slackydude at gmail.com]

Hi,
i'm trying to make a download manager (getright, flashget, etc..) for
linux (pygtk), i'm using pyCurl, so the thing is..
the app need to be able to use mirrors, like : i download the first 400
kb from X, and the second 200 kb from Y and the rest from Z.
i've plan to do this with threads and using Locks (This question has
been here before, so i have an idea..)
but the thing is, What if the app don't download a complete file in a
session (the user close the app, etc) and wants to complete the
download? Ok, i can seek the file and start to download again. but
where or how can i store that info?(where i left the download).

any ideas appreciated.