Re: [precis] order of operations (was: Re: Milestones changed for precis WG)

Sam Whited <sam@samwhited.com> Wed, 04 May 2016 22:27 UTC

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From: Sam Whited <sam@samwhited.com>
Date: Wed, 4 May 2016 17:26:47 -0500
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To: Peter Saint-Andre <stpeter@stpeter.im>
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Subject: Re: [precis] order of operations (was: Re: Milestones changed for precis WG)
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On Wed, May 4, 2016 at 3:46 PM, Peter Saint-Andre <stpeter@stpeter.im>; wrote:
> There's also the question of whether preparation / pre-processing is all
> that useful. We added it so that constrained clients (e.g., clients that
> can't realistically perform normalization) could avoid most of the problems
> associated with having their strings rejected by a more powerful server that
> actually does enforcement and comparison. Whether we really need to consider
> such applications is another story.

I'd be curious to know a "real world" use case for the preparation
step optimization where enforcement is prohibitively expensive and
comparison is not necessary (since comparison necessitates
enforcement)? While benchmarking the implementation I did for Go I
decided that it wasn't necessary to include a preparation step. Even
on a heavily resource constrained server the enforcement step was easy
to run concurrently or in parallel, and was very fast, even in its
unoptimized form (most of the time spent in the algorithm was on
memory allocation, which could easily be reduced). You can't count on
concurrency or parallelism in all systems of course, but since it also
wasn't all that time complex my suspicion is that the preparation step
is premature optimization even on synchronous systems (although I
haven't actually tested this).

—Sam

-- 
Sam Whited
pub 4096R/54083AE104EA7AD3
https://blog.samwhited.com