p2p/discover: optimize findnodeByID

[Sahil-4555]

@taratorio @yperbasis @anacrolix @AskAlexSharov
Optimize findnodeByID function and improve benchmark

goos: linux
goarch: amd64
pkg: github.com/erigontech/erigon/p2p/discover
cpu: Intel(R) Core(TM) i7-8565U CPU @ 1.80GHz
                                                          │ new_bench.txt │             old_bench.txt             │
                                                          │    sec/op     │    sec/op     vs base                 │
_findnodeByID/SmallTable_5Results_NoPreferLive-8             1.270µ ± 10%   1.223µ ±  5%         ~ (p=0.240 n=10)
_findnodeByID/SmallTable_16Results_NoPreferLive-8            1.566µ ± 13%   1.605µ ±  8%         ~ (p=1.000 n=10)
_findnodeByID/SmallTable_5Results_PreferLive_AllLive-8       1.234µ ± 13%   2.255µ ±  7%   +82.77% (p=0.000 n=10)
_findnodeByID/SmallTable_16Results_PreferLive_AllLive-8      1.701µ ±  5%   3.006µ ±  3%   +76.74% (p=0.000 n=10)
_findnodeByID/SmallTable_5Results_PreferLive_HalfLive-8      1.330µ ± 12%   2.200µ ±  8%   +65.44% (p=0.000 n=10)
_findnodeByID/SmallTable_16Results_PreferLive_HalfLive-8     1.725µ ± 10%   3.232µ ±  8%   +87.42% (p=0.000 n=10)
_findnodeByID/MediumTable_5Results_NoPreferLive-8            1.260µ ± 13%   1.279µ ±  6%         ~ (p=0.897 n=10)
_findnodeByID/MediumTable_16Results_NoPreferLive-8           1.828µ ±  6%   1.583µ ± 13%   -13.38% (p=0.001 n=10)
_findnodeByID/MediumTable_5Results_PreferLive_AllLive-8      1.297µ ±  8%   2.228µ ±  7%   +71.81% (p=0.000 n=10)
_findnodeByID/MediumTable_16Results_PreferLive_AllLive-8     1.712µ ±  4%   3.056µ ±  6%   +78.50% (p=0.000 n=10)
_findnodeByID/MediumTable_5Results_PreferLive_HalfLive-8     1.255µ ± 13%   2.199µ ±  7%   +75.22% (p=0.000 n=10)
_findnodeByID/MediumTable_16Results_PreferLive_HalfLive-8    1.630µ ±  5%   2.944µ ± 11%   +80.61% (p=0.000 n=10)
_findnodeByID/LargeTable_5Results_NoPreferLive-8             1.592µ ±  9%   1.670µ ± 11%         ~ (p=0.109 n=10)
_findnodeByID/LargeTable_16Results_NoPreferLive-8            2.090µ ±  8%   2.162µ ± 10%         ~ (p=0.315 n=10)
_findnodeByID/LargeTable_5Results_PreferLive_AllLive-8       1.481µ ± 12%   3.218µ ±  7%  +117.25% (p=0.000 n=10)
_findnodeByID/LargeTable_16Results_PreferLive_AllLive-8      1.970µ ±  9%   3.964µ ±  4%  +101.19% (p=0.000 n=10)
_findnodeByID/LargeTable_5Results_PreferLive_HalfLive-8      1.361µ ±  7%   2.723µ ±  8%  +100.15% (p=0.000 n=10)
_findnodeByID/LargeTable_16Results_PreferLive_HalfLive-8     1.802µ ±  6%   3.655µ ±  6%  +102.91% (p=0.000 n=10)
_findnodeByID/FullTable_5Results_NoPreferLive-8              1.438µ ± 17%   1.563µ ± 13%         ~ (p=0.247 n=10)
_findnodeByID/FullTable_16Results_NoPreferLive-8             1.954µ ±  7%   2.290µ ± 13%   +17.23% (p=0.000 n=10)
_findnodeByID/FullTable_5Results_PreferLive_AllLive-8        1.477µ ±  5%   3.304µ ±  7%  +123.74% (p=0.000 n=10)
_findnodeByID/FullTable_16Results_PreferLive_AllLive-8       1.958µ ±  6%   4.172µ ±  7%  +113.07% (p=0.000 n=10)
geomean                                                      1.566µ         2.379µ         +51.90%

                                                          │ new_bench.txt │            old_bench.txt             │
                                                          │     B/op      │    B/op     vs base                  │
_findnodeByID/SmallTable_5Results_NoPreferLive-8               248.0 ± 0%   248.0 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/SmallTable_16Results_NoPreferLive-8              376.0 ± 0%   376.0 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/SmallTable_5Results_PreferLive_AllLive-8         248.0 ± 0%   368.0 ± 0%  +48.39% (p=0.000 n=10)
_findnodeByID/SmallTable_16Results_PreferLive_AllLive-8        376.0 ± 0%   624.0 ± 0%  +65.96% (p=0.000 n=10)
_findnodeByID/SmallTable_5Results_PreferLive_HalfLive-8        248.0 ± 0%   368.0 ± 0%  +48.39% (p=0.000 n=10)
_findnodeByID/SmallTable_16Results_PreferLive_HalfLive-8       376.0 ± 0%   624.0 ± 0%  +65.96% (p=0.000 n=10)
_findnodeByID/MediumTable_5Results_NoPreferLive-8              248.0 ± 0%   248.0 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/MediumTable_16Results_NoPreferLive-8             376.0 ± 0%   376.0 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/MediumTable_5Results_PreferLive_AllLive-8        248.0 ± 0%   368.0 ± 0%  +48.39% (p=0.000 n=10)
_findnodeByID/MediumTable_16Results_PreferLive_AllLive-8       376.0 ± 0%   624.0 ± 0%  +65.96% (p=0.000 n=10)
_findnodeByID/MediumTable_5Results_PreferLive_HalfLive-8       248.0 ± 0%   368.0 ± 0%  +48.39% (p=0.000 n=10)
_findnodeByID/MediumTable_16Results_PreferLive_HalfLive-8      376.0 ± 0%   624.0 ± 0%  +65.96% (p=0.000 n=10)
_findnodeByID/LargeTable_5Results_NoPreferLive-8               248.0 ± 0%   248.0 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/LargeTable_16Results_NoPreferLive-8              376.0 ± 0%   376.0 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/LargeTable_5Results_PreferLive_AllLive-8         248.0 ± 0%   368.0 ± 0%  +48.39% (p=0.000 n=10)
_findnodeByID/LargeTable_16Results_PreferLive_AllLive-8        376.0 ± 0%   624.0 ± 0%  +65.96% (p=0.000 n=10)
_findnodeByID/LargeTable_5Results_PreferLive_HalfLive-8        248.0 ± 0%   368.0 ± 0%  +48.39% (p=0.000 n=10)
_findnodeByID/LargeTable_16Results_PreferLive_HalfLive-8       376.0 ± 0%   624.0 ± 0%  +65.96% (p=0.000 n=10)
_findnodeByID/FullTable_5Results_NoPreferLive-8                248.0 ± 0%   248.0 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/FullTable_16Results_NoPreferLive-8               376.0 ± 0%   376.0 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/FullTable_5Results_PreferLive_AllLive-8          248.0 ± 0%   368.0 ± 0%  +48.39% (p=0.000 n=10)
_findnodeByID/FullTable_16Results_PreferLive_AllLive-8         376.0 ± 0%   624.0 ± 0%  +65.96% (p=0.000 n=10)
geomean                                                        305.4        406.8       +33.21%
¹ all samples are equal

                                                          │ new_bench.txt │             old_bench.txt             │
                                                          │   allocs/op   │  allocs/op   vs base                  │
_findnodeByID/SmallTable_5Results_NoPreferLive-8               6.000 ± 0%    6.000 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/SmallTable_16Results_NoPreferLive-8              7.000 ± 0%    7.000 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/SmallTable_5Results_PreferLive_AllLive-8         6.000 ± 0%   10.000 ± 0%  +66.67% (p=0.000 n=10)
_findnodeByID/SmallTable_16Results_PreferLive_AllLive-8        7.000 ± 0%   12.000 ± 0%  +71.43% (p=0.000 n=10)
_findnodeByID/SmallTable_5Results_PreferLive_HalfLive-8        6.000 ± 0%   10.000 ± 0%  +66.67% (p=0.000 n=10)
_findnodeByID/SmallTable_16Results_PreferLive_HalfLive-8       7.000 ± 0%   12.000 ± 0%  +71.43% (p=0.000 n=10)
_findnodeByID/MediumTable_5Results_NoPreferLive-8              6.000 ± 0%    6.000 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/MediumTable_16Results_NoPreferLive-8             7.000 ± 0%    7.000 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/MediumTable_5Results_PreferLive_AllLive-8        6.000 ± 0%   10.000 ± 0%  +66.67% (p=0.000 n=10)
_findnodeByID/MediumTable_16Results_PreferLive_AllLive-8       7.000 ± 0%   12.000 ± 0%  +71.43% (p=0.000 n=10)
_findnodeByID/MediumTable_5Results_PreferLive_HalfLive-8       6.000 ± 0%   10.000 ± 0%  +66.67% (p=0.000 n=10)
_findnodeByID/MediumTable_16Results_PreferLive_HalfLive-8      7.000 ± 0%   12.000 ± 0%  +71.43% (p=0.000 n=10)
_findnodeByID/LargeTable_5Results_NoPreferLive-8               6.000 ± 0%    6.000 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/LargeTable_16Results_NoPreferLive-8              7.000 ± 0%    7.000 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/LargeTable_5Results_PreferLive_AllLive-8         6.000 ± 0%   10.000 ± 0%  +66.67% (p=0.000 n=10)
_findnodeByID/LargeTable_16Results_PreferLive_AllLive-8        7.000 ± 0%   12.000 ± 0%  +71.43% (p=0.000 n=10)
_findnodeByID/LargeTable_5Results_PreferLive_HalfLive-8        6.000 ± 0%   10.000 ± 0%  +66.67% (p=0.000 n=10)
_findnodeByID/LargeTable_16Results_PreferLive_HalfLive-8       7.000 ± 0%   12.000 ± 0%  +71.43% (p=0.000 n=10)
_findnodeByID/FullTable_5Results_NoPreferLive-8                6.000 ± 0%    6.000 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/FullTable_16Results_NoPreferLive-8               7.000 ± 0%    7.000 ± 0%        ~ (p=1.000 n=10) ¹
_findnodeByID/FullTable_5Results_PreferLive_AllLive-8          6.000 ± 0%   10.000 ± 0%  +66.67% (p=0.000 n=10)
_findnodeByID/FullTable_16Results_PreferLive_AllLive-8         7.000 ± 0%   12.000 ± 0%  +71.43% (p=0.000 n=10)
geomean                                                        6.481         9.051       +39.66%
¹ all samples are equal

[anacrolix]

Not sure why that tool shows improvements in timing in positive direction 😕.

Is this code actually a bottleneck at present?

[Sahil-4555]

@anacrolix

The benchmark shows positive percentages because the comparison is done as original → optimized (optimized vs original version).
So a positive value here means: “old was X% slower than new”, which is why the tool displays it as a positive improvement.

If the comparison were reversed (optimized → original), the tool would show the same change as a negative percentage.

You can verify this by running the benchmark locally with swapped inputs.