Add benchmark results and update gitignore for BenchmarkDotNet

.gitignore

@@ -47,6 +47,9 @@ project.lock.json
 project.fragment.lock.json
 artifacts/
 
+# BenchmarkDotNet
+BenchmarkDotNet.Artifacts/
+
 *_i.c
 *_p.c
 *_i.h

README.md

@@ -8,7 +8,7 @@ A lightweight .NET library that converts `IEnumerable<T>` into an `IDataReader`,
 - **Automatic property mapping** -- public properties are discovered automatically when no explicit mapping is provided.
 - **Fluent column mapping API** -- choose exactly which columns to expose using expression-based or delegate-based mappings.
 - **Computed columns** -- map constant values or derived expressions that don't correspond to a property.
-- **Multi-target** -- supports .NET 8.0, .NET 9.0, and .NET 10.0.
+- **Multi-target** -- supports .NET 9.0 and .NET 10.0.
 
 ## Installation
 
@@ -112,6 +112,33 @@ dotnet test
 dotnet run --project benchmarks/EnumerableDataReaderAdapter.Benchmarks -c Release
 ```
 
+### Results
+
+The benchmarks measure reading 10,000 rows through the `IDataReader` interface using different mapping strategies and column access patterns on .NET 10.0.
+
+```
+BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
+unknown 2.10GHz, 1 CPU, 16 logical and 16 physical cores
+.NET SDK 10.0.103
+  [Host]    : .NET 10.0.3 (10.0.3, 10.0.326.7603), X64 RyuJIT x86-64-v4
+  .NET 10.0 : .NET 10.0.3 (10.0.3, 10.0.326.7603), X64 RyuJIT x86-64-v4
+
+Job=.NET 10.0  Runtime=.NET 10.0
+```
+
+| Method                                         | N     | Mean     | Error     | StdDev    | Ratio | RatioSD | Rank | Gen0    | Allocated | Alloc Ratio |
+|----------------------------------------------- |------ |---------:|----------:|----------:|------:|--------:|-----:|--------:|----------:|------------:|
+| DefaultMapping_ByColumnIndex                   | 10000 | 1.977 ms | 0.0393 ms | 0.0623 ms |  1.00 |    0.04 |    1 | 85.9375 | 352.23 KB |        1.00 |
+| MappingExpressions_ByColumnIndex               | 10000 | 2.047 ms | 0.0406 ms | 0.0732 ms |  1.04 |    0.05 |    1 | 89.8438 | 366.67 KB |        1.04 |
+| MappingExpressions_ByColumnIndex_CachedMapping | 10000 | 1.982 ms | 0.0385 ms | 0.0564 ms |  1.00 |    0.04 |    1 | 85.9375 | 352.29 KB |        1.00 |
+| MappingDelegates_ByColumnIndex                 | 10000 | 1.970 ms | 0.0392 ms | 0.0575 ms |  1.00 |    0.04 |    1 | 85.9375 | 352.53 KB |        1.00 |
+| MappingDelegates_ByColumnIndex_CachedMapping   | 10000 | 1.969 ms | 0.0391 ms | 0.0841 ms |  1.00 |    0.05 |    1 | 85.9375 | 352.29 KB |        1.00 |
+| DefaultMapping_ByColumnName                    | 10000 | 2.053 ms | 0.0408 ms | 0.0705 ms |  1.04 |    0.05 |    1 | 85.9375 | 352.23 KB |        1.00 |
+| MappingExpressions_ByColumnName                | 10000 | 2.268 ms | 0.0450 ms | 0.0776 ms |  1.15 |    0.05 |    2 | 89.8438 |  366.6 KB |        1.04 |
+| MappingExpressions_ByColumnName_CachedMapping  | 10000 | 2.006 ms | 0.0385 ms | 0.0804 ms |  1.02 |    0.05 |    1 | 85.9375 | 352.29 KB |        1.00 |
+| MappingDelegates_ByColumnName                  | 10000 | 2.016 ms | 0.0397 ms | 0.0441 ms |  1.02 |    0.04 |    1 | 85.9375 | 352.53 KB |        1.00 |
+| MappingDelegates_ByColumnName_CachedMapping    | 10000 | 2.024 ms | 0.0389 ms | 0.0519 ms |  1.02 |    0.04 |    1 | 85.9375 | 352.37 KB |        1.00 |
+
 ## License
 
 [MIT](LICENSE) -- Copyright (c) 2018 Dimo Terziev

benchmarks/EnumerableDataReaderAdapter.Benchmarks/EnumerableDataReaderAdapter.Benchmarks.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>net8.0;net9.0;net10.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net10.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>

benchmarks/EnumerableDataReaderAdapter.Benchmarks/Program.cs

@@ -23,7 +23,6 @@ public DataStructure(
 
     }
 
-    [SimpleJob(BenchmarkDotNet.Jobs.RuntimeMoniker.Net80)]
     [SimpleJob(BenchmarkDotNet.Jobs.RuntimeMoniker.Net90)]
     [SimpleJob(BenchmarkDotNet.Jobs.RuntimeMoniker.Net10_0)]
     [RPlotExporter, RankColumn]

src/EnumerableDataReaderAdapter/EnumerableDataReaderAdapter.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net8.0;net9.0;net10.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net10.0</TargetFrameworks>
   </PropertyGroup>
 
 </Project>

src/EnumerableDataReaderAdapter/EnumerableExtensions.cs

@@ -1,4 +1,5 @@
 using System.Collections;
+using System.Collections.Frozen;
 using System.Data;
 using System.Data.Common;
 using System.Runtime.CompilerServices;
@@ -39,7 +40,8 @@ private sealed class EnumerableReaderAdapter<T> : DbDataReader
             private bool _isClosed = false;
             private IEnumerator<T> _enumerator;
             private T _current = default!;
-            private readonly Lazy<Dictionary<string, int>> _columnLookup;
+            private readonly FrozenDictionary<string, int> _columnLookup;
+            private readonly FrozenDictionary<string, int>.AlternateLookup<ReadOnlySpan<char>> _alternateLookup;
             private long _rowCount = 0;
 
             public EnumerableReaderAdapter(
@@ -48,15 +50,14 @@ public EnumerableReaderAdapter(
             {
                 _enumerator = rows.GetEnumerator();
                 _mappings = mappings;
-                _columnLookup = new Lazy<Dictionary<string, int>>(() =>
+
+                var dict = new Dictionary<string, int>(mappings.Length);
+                for (int i = 0; i < mappings.Length; i++)
                 {
-                    var result = new Dictionary<string, int>(_mappings.Length);
-                    for (int i = 0; i < _mappings.Length; i++)
-                    {
-                        result.Add(_mappings[i].ColumnName, i);
-                    }
-                    return result;
-                });
+                    dict.Add(mappings[i].ColumnName, i);
+                }
+                _columnLookup = dict.ToFrozenDictionary();
+                _alternateLookup = _columnLookup.GetAlternateLookup<ReadOnlySpan<char>>();
             }
 
             public override bool HasRows => true;
@@ -125,20 +126,21 @@ public override void Close()
             }
 
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
-            public override int GetOrdinal(string name) => _columnLookup.Value[name];
+            public override int GetOrdinal(string name) => _alternateLookup[name.AsSpan()];
 
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             public override object GetValue(int i) => _mappings[i].ValueGetter(_current)!;
 
             public override int GetValues(object?[] values)
             {
-                var max = values.Length < _mappings.Length
-                    ? values.Length
-                    : _mappings.Length;
+                var max = Math.Min(values.Length, _mappings.Length);
 
-                for (int i = 0; i < max; i++)
+                ReadOnlySpan<(string ColumnName, Type ColumnType, Func<T, object?> ValueGetter)> mappingSpan = _mappings.AsSpan(0, max);
+                Span<object?> valuesSpan = values.AsSpan(0, max);
+
+                for (int i = 0; i < mappingSpan.Length; i++)
                 {
-                    values[i] = _mappings[i].ValueGetter(_current);
+                    valuesSpan[i] = mappingSpan[i].ValueGetter(_current);
                 }
 
                 return max;
@@ -167,7 +169,14 @@ public override int GetValues(object?[] values)
             public override string GetString(int i) => (string)GetValue(i);
             public override decimal GetDecimal(int i) => (decimal)GetValue(i);
             public override DateTime GetDateTime(int i) => (DateTime)GetValue(i);
-            public override bool IsDBNull(int i) => GetValue(i) == null || GetValue(i) == DBNull.Value;
+
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            public override bool IsDBNull(int i)
+            {
+                var value = GetValue(i);
+                return value is null or DBNull;
+            }
+
             public override int FieldCount => _mappings.Length;
         }
     }

test/EnumerableDataReaderAdapter.Tests/EnumerableDataReaderAdapter.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net8.0;net9.0;net10.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net10.0</TargetFrameworks>
 
     <IsPackable>false</IsPackable>
   </PropertyGroup>