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Re: [Chicken-users] News from the Barnyard
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From: |
Joerg F. Wittenberger |
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Subject: |
Re: [Chicken-users] News from the Barnyard |
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Date: |
12 Jun 2003 14:39:01 +0200 |
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User-agent: |
Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 |
Hello all,
Felix Winkelmann <address@hidden> writes:
> I'm currently working on a (simple - hm... I'm using the
> word like an apology... ;-) web-server, that uses the
> HTTP extension. The performance is so-so, about twice as
> fast as the SUnet server (considering raw requests-per-second)
> but still no match for the PLT server. Anyway, it works and
> is quite easy to use. I have thought about a simple method
> of embedding scheme in HTML and now something a la PHP came
> out, so you would have, say,
>
> <html><head><title>Hello</title><head>
> <?scheme
> (printf "<h1>This is ~A, on ~A</h1>"
> (http:request-url (spiffy:current-request))
> (get-host-name) )
> ?>
> <body>
> </body>
> </html>
>
> So everything in "<?scheme ...?>" or "<?...?>" is taken
Felix, you know (while the others here don't) chicken can do this a
lot more already.
I'm proud to announce that it was just decided to release the chicken
port of Askemos under the BSD license.
The port is _not_ yet as functional as the rscheme implementation is.
Asynchronous DNS resolution (PLT style) is missing and there is a
unlocated bug in the handling of large Strings including
NUL-Characters (as with picture content). It might also not fully
compile right now, but it happened to work a few weeks ago, though it
seems to stress the chicken as well as the rscheme system heavily.
The tarball is available from
http://www.askemos.org:9080/askemos-chicken.tar.gz
What is Askemos?
Askemos is a distributed operating system in Scheme (mostly R5RS).
See http://www.softeyes.net/PUBLde for papers (avoid the german
translation of the 2002 paper) and presentations as well as
www.askemos.org and it's replicates running the Askemos quorum to find
a Wiki, which holds documentation and a confusing amount of all kinds
of related notes.
As a content management system you get with Askemos something poorly
documented (working here currently), which feels like Zope in Scheme
acknowledging the market pressure towards XML. In addition to
Oleg's/Kirill's SXPath you get a little closer to a complete, lazy
evaluated XSLT implementation (though not too complete) and a limited
DSSSL. PDF is via Lout and htmldoc. SRFI 19 with l18n modifications.
The rscheme version provides a native XML database (yes, pointer
swizzling at page fault time is _much_ faster than writing XML files
in reference syntax - what the chicken version relies on right now; we
should instead use chickens evict/unevict there).
Processes and transactions are either performed at a single machine or
synchronized using byzantine protocols on the majority of a network of
machines (making the distributed CMS intrusion resistant) and an
access control system based on set theory, which is proven to be
incorruptible. (The latter is actually the novelty about Askemos; see
the papers and presentations.)
Access is through HTTP(S) and SMTP currently. (Great: Felix just
announced POP code candidate?! ;-)
Performance: Both the rscheme and the chicken come with some C code
optimizing the serialization of XML. Both version show no significant
difference to apache for unprocessed objects. The rscheme version
needs approximately 4 times as long for dynamic results of the same
size generated by two passes of document transformation in XSLT/DSSSL
style.
The chicken version is worse here. This seems to be a low level issue
of the calling convention. I'd love to cooperate with Felix and
investigate that.
Cheers
/Jörg
--
The worst of harm may often result from the best of intentions.