On 10/08/2010 03:46 PM, Glyph Lefkowitz wrote: > > On Oct 8, 2010, at 9:25 AM, exar...@twistedmatrix.com > <mailto:exar...@twistedmatrix.com> wrote: > >> On 5 Oct, 08:09 pm, stephen.c.waterb...@nasa.gov >> <mailto:stephen.c.waterb...@nasa.gov> wrote: >>> First, the "PB Copyable: Passing Complex Types" doc is >>> *great* and the examples are excellent -- my compliments to >>> all who contributed! >>> >>> My question is about the pb.Cacheable section >>> (http://twistedmatrix.com/documents/current/core/howto/pb- >>> copyable.html#auto9) >>> -- specifically the first sentence: 'Sometimes the object you >>> want to send to the remote process is big and slow. "big" means >>> it takes a lot of data (storage, network bandwidth, processing) >>> to represent its state. "slow" means that state doesn't change >>> very frequently.' >>> >>> I would think that the product of its size and its rate of change >>> is the applicable metric -- i.e.: the bigger the object is *or* >>> the faster it changes (not the slower), the more applicable >>> Cacheable is, no? >> >> That seems plausible. I wonder if the rate comment is motivated by >> something else, like the chance of the remote cache being out of date >> when the remote side wants to use some of its data. This would increase >> with the rate of change, but I don't know if it really matters. I >> haven't ever actually used a Cacheable myself, as far as I can recall. > > I think I probably wrote that paragraph, and it was not very well put. > Big objects which are "fast", i.e. change constantly, are perfectly > suitable for Cacheables. > > The point I believe I was trying to make there was that if /a > significant proportion/ of the object's data is changing quickly, > Cacheable doesn't make much of a difference over just re-Copyable-ing > the whole object, since the delta updates will be the same size as the > whole object.
Certainly true. Again, the documentation and the examples are great, anyway, so that part is not a big deal, I was just curious. Thanks, Glyph. Cheers, Steve _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
