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Thanks Pablo!<br>
this looks pretty clear and neat, I'll try it out.<br>
<br>
Just one newbie question - is the "_" in "acquire_cb(_)" just a
placeholder for my own parameters, or does it have an actual meaning?<br>
I've never seen this done in python before, and couldn't find other
examples for it online...<br>
<br>
Cheers,<br>
Nadav<br>
<br>
<br>
Pablo Martí wrote:
<blockquote cite="mid:1189755451.12076.16.camel@satellite" type="cite">
<pre wrap="">On Fri, 2007-09-14 at 00:58 -0400, Nadav Aharony wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Hi,
I am working on an application where clients request files, and since
each file is very large, the server ACKs the requests and then queues
them to be served later, one at a time.
I am relatively new to Twisted and was wondering what would be the
best way to approach this.
</pre>
</blockquote>
<pre wrap=""><!---->
Hi Nadav,
I had a similar requirement with my application. You must offer an
asynchronous interface while dealing with each request synchronously. I
think that you should push your requests to a
twisted.internet.defer.DeferredQueue and process one at a time with the
aid of twisted.internet.defer.DeferredLock.
</pre>
<pre wrap=""><!---->
If we consider that each of your petitions has an associated deferred
that will be called back when its finished:
(I haven't run this)
from twisted.internet import defer
class OneAtATime(object):
def __init__(self):
super(OneAtATime, self).__init__()
self.queue = defer.DeferredQueue()
self.lock = defer.DeferredLock()
self.check_queue()
def check_queue(self):
self.queue.get().addCallback(self._process_one)
def _process_one(self, petition):
def acquire_cb(_):
# do whatever with your petition
# make sure that when you're done you call
# self.lock.release() and self.check_queue()
# on a state machine, this would be while transitioning
# to the "idle" state
pass
self.lock.acquire().addCallback(acquire_cb)
def queue_petition(self, petition):
self.queue.put(petition)
return petition.deferred
Regards,
Pablo
</pre>
<pre wrap=""><!---->
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</blockquote>
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