[Xitami] Small modification to ISAPI support

[JLIST]

Hello Russel,

> In the defaults.cfg file add a filter extension ...

I'll try this and report back. Thanks for the suggestion.

> How much faster is ISAPI versus CGI - and what language are the dll's
> written in?  At least for me, this method you have described is new to me.

ISAPI is very fast because it'll be just a function call in the same
Win32 process. Howerver, running ISAPI on Xitami has the overhead of
going through LRWP, which should still be fairly fast. All the
approaches (ISAPI, apache modules, LRWP, FastCGI, SCGI, AJP13) avoid
the overhead of starting a new process (in the CGI's case) and the
time the process needs for initialization. I don't have the numbers
but you should be able to find some numbers on the Net. The idea is
the same for LWRP/FCGI/SCGI/AJP, which is to use a long running
process.

I think you can write the DLL in any language that can be used to
write a DLL. I use VC++ or Delphi. This is another reason why ISAPI
is faster - the DLLs are usually written in compiled languages.

If xitami becomes my main server for Windows (I'm still evaluating),
I think I'll also use Python to write some LRWP. I've verified that
the Python module works. They'll usually still be much faster than
CGIs because the time it takes to process the request are much
shorter than the time for Windows to start a process. It takes time
and it taxes the server quite a bit to start processes. That's why
I generally stay away from CGI.

But I still miss FastCGI/SCGI a lot because, other than the advantages
that FastCGI has, I have developed some code that run as FCGI/SCGI
and there are a lot of web development frameworks that support these protocols.
I think it would be a great idea for xitami to support FCGI/SCGI.

Jack