Two features I don't understand

[Alex Tweedly]

On 31/10/2014 04:04, Richard Gaskin wrote:
> Alex Tweedly wrote:
>> Hmmmm - I said this once before :-) :-)
>
> My apologies for the inconvenience.  I'd either missed it before or 
> completely forgot about it, but the latter seems unlikely given how 
> remarkable the post was:
>

Oh Richard - I even threw in 2 smiley faces so you would *know* I was 
teasing you :-)

>>> in 5.5.3
>>> name takes 830 ms while id takes only 250 ms
>>>
>>> but in 6.0 (i.e. with id caching)
>>> name takes 830 ms while id takes 5 ms
>>>
>>> -- Alex.
>>>
>>>
>
> What I find most remarkable is the way your benchmark makes the value 
> of this ID caching seem rather trivial.
>
> I trust this was a one-liner, as I can't imagine them spending much 
> time optimizing something so very specialized and which takes so 
> little execution time per iteration.
>
> I wonder what prompted this one...perhaps something specific to the 
> coding style of the person who wrote the Project Browser?
>
It is a trivial example - but the speed-up of 50X seems significant.

It's not just *the* most recent ID that is cached (at least according to 
a simple-minded test I did - see the original thread for details). It 
does appear that it speeds up access to a number of cached IDs. So if 
you had a lot of controls (Datagrid ??) and were doing something to them 
multiple times (scrolling?, fading in/out, ...) then maybe it would be 
noticeable, if not actually significant.

Anyway - this is one way to test it - whether or not you find it useful.
Probably worth adding it to the compare-engine-versions benchmark; I'll 
do that once a framework / sample of that happens.

--Alex.