benchmark arrays

src/DotRecast.Core/Buffers/RcRentedArray.cs

@@ -19,6 +19,7 @@ namespace DotRecast.Core.Buffers
         private T[] _array;
 
         public int Length { get; }
+        public bool IsDisposed => null == _owner || null == _array;
 
         internal RcRentedArray(ArrayPool<T> owner, T[] array, int length)
         {
@@ -37,6 +38,11 @@ namespace DotRecast.Core.Buffers
             }
         }
 
+        public T[] AsArray()
+        {
+            return _array;
+        }
+
 
         public void Dispose()
         {

test/DotRecast.Core.Test/RcArrayBenchmarkTests.cs

@@ -0,0 +1,101 @@
+using System;
+using System.Buffers;
+using System.Collections.Generic;
+using DotRecast.Core.Buffers;
+using DotRecast.Core.Collections;
+using NUnit.Framework;
+
+namespace DotRecast.Core.Test;
+
+public class RcArrayBenchmarkTests
+{
+    private const int StepLength = 512;
+    private const int RandomLoop = 1000;
+    private readonly RcRand _rand = new RcRand();
+
+    private (string title, long ticks) Bench(string title, Action<int> source)
+    {
+        var begin = RcFrequency.Ticks;
+        for (int step = StepLength; step > 0; --step)
+        {
+            for (int i = 0; i < RandomLoop; ++i)
+            {
+                source.Invoke(step);
+            }
+        }
+
+        var end = RcFrequency.Ticks - begin;
+        return (title, end);
+    }
+
+
+    private void RoundForArray(int len)
+    {
+        var array = new int[len];
+        for (int ii = 0; ii < len; ++ii)
+        {
+            array[ii] = _rand.NextInt32();
+        }
+    }
+
+
+    private void RoundForPureRentArray(int len)
+    {
+        var array = ArrayPool<int>.Shared.Rent(len);
+        for (int ii = 0; ii < array.Length; ++ii)
+        {
+            array[ii] = _rand.NextInt32();
+        }
+
+        ArrayPool<int>.Shared.Return(array);
+    }
+
+
+    private void RoundForRcRentedArray(int len)
+    {
+        using var rentedArray = RcRentedArray.Rent<int>(len);
+        var array = rentedArray.AsArray();
+        for (int i = 0; i < rentedArray.Length; ++i)
+        {
+            array[i] = _rand.NextInt32();
+        }
+    }
+
+
+    private void RoundForRcStackArray(int len)
+    {
+        var array = new RcStackArray512<int>();
+        for (int ii = 0; ii < len; ++ii)
+        {
+            array[ii] = _rand.NextInt32();
+        }
+    }
+
+    private void RoundForStackalloc(int len)
+    {
+        Span<int> array = stackalloc int[len];
+        for (int ii = 0; ii < len; ++ii)
+        {
+            array[ii] = _rand.NextInt32();
+        }
+    }
+
+
+    [Test]
+    public void TestBenchmarkArrays()
+    {
+        var list = new List<(string title, long ticks)>();
+        list.Add(Bench("new int[len]", RoundForArray));
+        list.Add(Bench("ArrayPool<int>.Shared.Rent(len)", RoundForPureRentArray));
+        list.Add(Bench("RcRentedArray.Rent<int>(len)", RoundForRcRentedArray));
+        list.Add(Bench("new RcStackArray512<int>()", RoundForRcStackArray));
+        list.Add(Bench("stackalloc int[len]", RoundForStackalloc));
+
+        list.Sort((x, y) => x.ticks.CompareTo(y.ticks));
+
+        foreach (var t in list)
+        {
+            Console.WriteLine($"{t.title} {t.ticks / (double)TimeSpan.TicksPerMillisecond} ms");
+        }
+    }
+}