search

MetacoSA / NBitcoin

Comprehensive Bitcoin library for the .NET framework.
MIT License
1.85k stars 839 forks source link

`OutPoint`: Use `CompareTo` in `operator==` #1191

Closed kiminuo closed 8 months ago

kiminuo commented 8 months ago

I have not measured the change but it seems that for many cases it should be faster.

lontivero commented 8 months ago

I don't think it improves the perf. It should be measured. Also, I think N follows the Benford's law. Most Ns are 0 then 1, then 2, then 3 and so on.

kiminuo commented 8 months ago

I don't think it improves the perf.

You are seem to be right. It goes very much against my intuition but bechmarks confirm your opinion (it's actually much slower in the current benchmark).

Interestingly changing:

-return (a.hash == b.hash && a.n == b.n);
+return (a.hash == b.hash && a.n.CompareTo(b.n) == 0);

seems to show like 8% improvement on the benchmark

dotnet build -c Release --framework net6.0 && dotnet run -c Release -f net6.0 -- --runtimes net6.0 --filter *OutPointBench*
Method Mean Error StdDev
Old 539.4 ms 7.11 ms 6.30 ms
New 479.9 ms 7.51 ms 7.03 ms

I'm not sure why.

I don't want to invest too much time in this PR as the original proved to be a bad one. But if the improvement sounds good and it actually exists, then I can finish this PR.