[REBOL] Re: This is dumb (don't do it!)
From: SunandaDH:aol at: 30-Jan-2004 12:29
Hi Hallvard,
> OK, the reason I did this, is I wonder if I can have a CGI script close the
> connection to user and then continue processing some data afterwards. So
that
> the web user wouldn't have to wait ages for the browser to tell him the
page
> has finished loading when actually it is.
>
> The following CGI script didn't do the trick. Anyone got an idea?
I tried to find a foolproof way of doing this for something we needed or
REBOL.org. I failed.
Part of the problem is that you can't control when the server sends the data.
If you only have a small amount of data (not enough to fill whatever is a
block transmitted across the Internet) that probably won't be until your CGI
quits.
I tried various cunning schemes, like explicitly setting a Content-length
header and then sending more data than that (to force a block transmit). They
didn't work.
In the end, in our case, as we only need to run some non-user background
stuff occasionally, I added some rudimentary code to check that the request is not
from a human being. So we only run the "background task" if the referrer is a
bot. I don't mind keeping them waiting a couple of seconds once in a while.
And the "background task" is self-limiting -- it'll stop after a couple of
seconds, whether it's finished or not.
The site is hit by bots hundreds of times a day -- so the background task
never has to wait long to resume.
This kludge works because the background processing we need to do is not
related to the current message -- it's the equivalent of an occasional recycle to
keep things current.
Of course, we have to check that the background task isn't already running
(if we get two bots that trigger it in the same second or so).
If you find a better solution, please let me know!
Sunanda.<
