Cache headers can be set for the whole site, a whole directory or just a
single file.
Also, the cache headers tell the Freewheel server when to check. If the time
has elapsed, the Freewheel server will check to see if the DWF is newer and
will only download the DWF if it is newer. Your suggestion is checking every
time is a good one. The problem is how often should the Freewheel server
check? The check can take more than a second depending several variables.
Should the server check after each frame? That would not work. Even a check
every hour, would be much for some servers. It is best to set the cache
headers on your DWF files and tell the Freewheel servers how often to check.
Ben
wrote in message news:5666925@discussion.autodesk.com...
Regarding caching, I may not want to change the cache settings for my entire
site just to accommodate Freewheel's caching policy.
I also may be using freewheel on my site against URL's containing DWF's from
a third remote site where I have no control over their servers caching.
Can you add an optional parameter to your server which allows me to use a:
,,,,&forcecachereload=1 sort of option?
Commenting on previous discussion, checking changes in the file based on
file sizes is obviously a bad idea, however you could certainly checksum
them. In fact, (I'd bet but I'm guessing) that the DWF format itself has a
checksum in the file? If so, perhaps you could use that to first use the
checksum to validate your cached version and upload the rest of the file if
the checksum is different.
(of course now you're trading off two roundtrips, but given the size of the
files, it's probably worth it.)
-Steve.