Automatic version control & updates in Adobe AIR application

What I'm trying to do, is an Adobe AIR application that could update automatically, but would only download开发者_如何学Python data files that have been changed since the last update. Sort of like SVN and other version control systems, except works only from server to users (ie. checkout only in SVN the comparison).

I know about the automatic update functionality in AIR and it works well to update the actual executable & binaries. However the application can have over 1 gigabyte of additional data (mostly HD video & hires images), so distributing that as a single .air package might not be the best idea, especially if the users' bandwidth is limited.

So in short: A (semi)automatic update system that can download only updated files from a web server instead of the entire application.

Basically I'm looking if there is either an open source or proprietary system that could do this out of the box or with least extra work.

doubt there is something out there that already does this for you, sounds like a pretty custom requirement. a good solution would be to avoid the automatic update altogether for this and do the following in your program's initialization (i.e, before the meat of the program starts)

1- check the creation or modification date of the files in question on the local system: http://livedocs.adobe.com/flex/3/html/help.html?content=Filesystem_01.html

2- call a server-side script to check the files in the remote location, i.e., the files you will keep up to date. something like this in PHP should help you get started: http://www.liamdelahunty.com/tips/php_list_a_directory.php

3- compare the sets of dates.

4- download the necessary files.

5- run the rest of your program.