On 2020/04/14 07:00:56, hahnjo wrote: > On 2020/04/13 21:01:11, hanwenn wrote: > > it's hard to say if this makes a measurable difference: > > > > [...] > > So then ... why do it at all? From a code perspective, a deep copy looks saner > in terms of "encapsulation" (one principle of object-oriented programming). If > there is no provable gain, I'm for leaving the current code alone until there is > good reason to change - "premature optimization is the root of all evil"
As I described in the commit message, this code doesn't protect anything, because get_property can also return values from the immutable list. Due to timing variability, we can't quantify performance changes below 1% of impact, but if we add 10 of them in a row, we do get measurable impact. For the Mutable_properties change, we saw seemingly consistent performance differences, which we could tease apart from deep copy change by separating out the commit. https://codereview.appspot.com/561640045/
