Leonardo Rochael Almeida wrote:

On Thu, 2003-12-11 at 01:50, Christian Tismer wrote:

[Stackless Zope App]

The key to this surprizing solution is
tasklets, channels, and thread pickling.

Let me know your thoughts...


This is very impressive. Can we get the rest of the source code? like,
what is the definition of "channel_send()"?

Well, this is all still a little ugly, and I didn't want to spoil the nice effect by such details. Actually, there are restrictions on what I can use from Stackless, since I'm writing in Restricted python. Without further additions to Stackless (which I din't understand, yet), Zope doesn't allow me to call methods on tasklets and channels, so I had to put things into external methods, which do these calls for me.

channel_send(ch, data)   is just a wrapper and actually does

same here:
stackless_tasklet(prog) is a wrapper that calls
stackless.tasklet(prog) since I cannot import my module.

Furthermore, these channels are not the builtin Stackless channels,
but a fake Python class, which implements channels in Python.
The reason was that Stackless channels don't have pickling support,
yet. Also a reason why I call this a "preview". Anyway, it works
and is not cheating.
You might be interested in the "driver" code, which is a Python
script as well (the "other side" that reads form the channel):

runDemo script:
# Example code:

# Import a standard function, and get the HTML request and response objects.
from Products.PythonScripts.standard import html_quote
request = container.REQUEST

# see whether we have a channel stored in the session

chname ='demo_channel'
session = request.SESSION
if not session.has_key(chname):
    ch = container.stackless_channel()
    t = container.stackless_tasklet(container.program)
    t(ch)  # bind parameter
    del t
    session[chname] = ch
ch = session[chname]
data = container.channel_receive(ch)
last = 0
if data is None:
    del session[chname]
    last = 1
return container.index_html(value=data, show_source=last)

I will put some more work into this if I get more feedback,
and add more infos to the website.

An interesting version would be to not use the session at
all, but send the pickle together with the web page.
That means to pickle by hand and to use encryption of course.

ciao - chris

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