a couple of benchmarks

Author: MithrilMan

MithrilShards.P2P.Benchmark/Benchmarks/Spot/BlockLocatorBuilding.cs

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+using System;
+using System.Buffers;
+using System.Collections.Generic;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+
+namespace MithrilShards.Network.Benchmark.Benchmarks
+{
+   [SimpleJob(RuntimeMoniker.NetCoreApp31)]
+   [RankColumn, MarkdownExporterAttribute.GitHub, MemoryDiagnoser]
+   public class BlockLocatorBuilding
+   {
+      [Params(1_000, 100_000, 10_000_000)]
+      public int top_height;
+
+      [Benchmark]
+      public Span<int> Log()
+      {
+         int itemsToAdd = this.top_height <= 10 ? (this.top_height + 1) : (10 + (int)Math.Ceiling(Math.Log2(this.top_height)));
+         Span<int> indexes = new Span<int>(ArrayPool<int>.Shared.Rent(itemsToAdd), 0, itemsToAdd);
+
+         int index = 0;
+         int current = this.top_height;
+         while (index < 10 && current > 0)
+         {
+            indexes[index++] = current--;
+         }
+
+         int step = 1;
+         while (current > 0)
+         {
+            indexes[index++] = current;
+            step *= 2;
+            current -= step;
+         }
+         indexes[itemsToAdd - 1] = 0;
+
+         return indexes;
+      }
+
+      [Benchmark]
+      public List<int> Loop()
+      {
+         // Modify the step in the iteration.
+         int step = 1;
+         List<int> indexes = new List<int>();
+
+         // Start at the top of the chain and work backwards.
+         for (int index = this.top_height; index > 0; index -= step)
+         {
+            // Push top 10 indexes first, then back off exponentially.
+            if (indexes.Count >= 10)
+               step *= 2;
+
+            indexes.Add(index);
+         }
+
+         //  Push the genesis block index.
+         indexes.Add(0);
+         return indexes;
+      }
+   }
+}

MithrilShards.P2P.Benchmark/Benchmarks/Spot/DiscardThrow.cs

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+using System;
+using System.Buffers;
+using System.Collections.Generic;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+
+namespace MithrilShards.Network.Benchmark.Benchmarks
+{
+   [SimpleJob(RuntimeMoniker.NetCoreApp31)]
+   [RankColumn, MarkdownExporterAttribute.GitHub, MemoryDiagnoser]
+   public class DiscardThrow
+   {
+      object data;
+
+      [GlobalSetup]
+      public void Setup()
+      {
+         this.data = new object();
+      }
+
+
+      [Benchmark]
+      public void WithDiscard() => WithDiscard(this.data);
+
+      public static void WithDiscard(object data)
+      {
+         _ = data ?? throw new Exception();
+      }
+
+      [Benchmark]
+      public void WithIf() => WithIf(this.data);
+
+      public static void WithIf(object data)
+      {
+         if (data == null)
+         {
+            throw new Exception();
+         }
+      }
+   }
+}