POV-Ray : Newsgroups : povray.general : return dictionary from macro [bug?] : Re: return dictionary from macro [bug?] Server Time
27 Oct 2021 06:00:48 EDT (-0400)
  Re: return dictionary from macro [bug?]  
From: William F Pokorny
Date: 19 Apr 2021 10:19:42
Message: <607d917e$1@news.povray.org>
On 4/18/21 6:46 AM, jr wrote:
> hi,
> 
> William F Pokorny <ano### [at] anonymousorg> wrote:
>> ... However, I need to test(1) with large dictionaries having
>> key hashing collisions to be sure my fixes - as well the previously
>> existing code - work correctly.
> 
> thought/wondered a little more about testing (increasingly?) large dictionaries,
> and made a monkeyed version ('foreach_d.inc') which has an option to add an
> adjustable delay between calls of a payload macro (up to a minute).  if thought
> useful, can provide a copy.
> 

Yes, please post. You suspected correctly the foreach include fit less a 
direct fit than I 'thought' it would be for my testing.

That said, not posted an update because I've been sliding sideways 
yesterday and today.

Off taking a closer look at our parser string hash function. It's fast, 
but the distribution(1) into the symbol hash table isn't very good - bad 
enough I first thought something wrong was wrong with my dictionary fixes.

Currently have a version based on c++11 std::hash which - so long as you 
compile at high optimizations - is looking really good for performance 
and distribution. This even with my presently clunky adoption of the 
library version in code.

(1) - The linked lists off each hash key get long. For 256 incremented, 
'A' prefixed keys, table entries very clustered and with list depths of 
up to 15.

I hope to be back to testing my dictionary fixes in the next few days.

Bill P.


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