QuerySelectorAll - performance

[jirisykora83]

I try to profile my app because i facing issue with performance (main reason why i recently switch from HAP). And i notice NodeList.get_Length() in QuerySelectorAll is take lot of time (almost 10%). Of course it depend on how much elements is in collection).

I want to try rewrite it with my custom QuerySelectorAll but i end with too many class is need to rewrite. Maybe you can try just save elements.Length to local variable it should get some percent of performance in this highly used function.

Testing with last stable version 0.9.9 but from first look at dev branch i think it is same in 0.1.0.
VS 2017 - release mode of course

[FlorianRappl]

I think caching one or the other thing may indeed be useful.

Caching elements.Length sounds like a small / notable gain without any side-effects or risks - thanks for the suggestion!

[campersau]

An example to reproduce your results would be helpful. Used HTML and CSS selectors.

[jirisykora83]

Sorry for late response i have short vacation.

Here is simplify version of my testing scenario (in my testing scenario i also extract some data but
i call QuerySelectorAll just on one other place).

For benchmark i use BenchmarkDotNet.

Example:
AngleSharpBenchmark.zip

[FlorianRappl]

Would be simpler to have a Gist.

[jirisykora83]

Ok here is the gist.

https://gist.github.com/jirisykora83/d1316a636d5f6c154872cc746c7654a1

[FlorianRappl]

Great, thanks!