Socket Performance

Gabriel Genellina gagsl-py2 at yahoo.com.ar
Sun Mar 16 19:29:10 CET 2008


En Sat, 15 Mar 2008 20:08:05 -0200, <castironpi at gmail.com> escribi�:
> On Mar 15, 8:18 am, Bryan Olson <fakeaddr... at nowhere.org> wrote:
>> castiro... at gmail.com wrote:

>> > Newbie question:  Can you write to the 'file-like object' a pickle,
>> > and receive it intact-- as one string with nothing else?
>>
>> Yes, but there's a world of gotcha's. Sockets do not recognize
>> record boundaries, and Python's 'pickle' has holes one's enemies
>> could drive a truck through. Still, you can pickle, write, read,
>> un-pickle, and get back your data intact.
>>
>> > I want to know because I want to send two pickles.
>>
>> "Two pickles" sounds like a tasty snack, but also suggests you may
>> be playing hopscotch in a minefield. This is a helpful group. Give
>> us more to go on, and you are likely to receive thousands of
>> dollars worth of consulting for free.
>
> It depends on the situation.  How generally applicable is this:
>
> fun ListenerGeneric( port, factory, arrivedfun ):
>
> which calls 'factory' on socketA.accept (and loops again), then
> arrivedfun( stringA ) on message complete detection.  ?.  It should
> start itself in a separate thread.
>
> Or is this any better:
>
> for x in connections():
>    startnewthreadwith x:
>       for y in messages( x ):
>          arrivedfun( y )

This looks like a SocketServer + ThreadingMixIn + a RequestHandler (your  
factory).
But as B. Olson already pointed, pickles are unsafe. Worse, it's not that  
someone could send a specially crafted pickle that could execute some  
arbitrary code: you're blindy executing whatever you receive!
xmlrpc may be a good alternative in some cases.

-- 
Gabriel Genellina




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