Improved GetDynamicRecords performance (#21)

CsvHelper.FastDynamic.Performance/CsvHelper.FastDynamic.Performance.csproj

@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="BenchmarkDotNet" Version="0.13.1" />
+    <PackageReference Include="BenchmarkDotNet" Version="0.13.2" />
   </ItemGroup>
 
   <ItemGroup>

CsvHelper.FastDynamic.Performance/Internal/CsvReaderExtension.cs

@@ -11,7 +11,7 @@ internal static IReadOnlyList<IDictionary<string, object>> GetDictionaryRecords(
 
     internal static IEnumerable<IDictionary<string, object>> EnumerateDictionaryRecords(this CsvReader csvReader)
     {
-        if (csvReader.Configuration.HasHeaderRecord && csvReader.HeaderRecord == null)
+        if (csvReader.Configuration.HasHeaderRecord && csvReader.HeaderRecord is null)
         {
             if (!csvReader.Read())
             {
@@ -53,4 +53,43 @@ internal static IEnumerable<IDictionary<string, object>> EnumerateDictionaryReco
             yield return record;
         }
     }
+
+    internal static IReadOnlyList<string[]> GetRawRecords(this CsvReader csvReader)
+        => csvReader.EnumerateRawRecords().ToArray();
+
+    internal static IEnumerable<string[]> EnumerateRawRecords(this CsvReader csvReader)
+    {
+        if (csvReader.Configuration.HasHeaderRecord && csvReader.HeaderRecord is null)
+        {
+            if (!csvReader.Read())
+            {
+                yield break;
+            }
+
+            csvReader.ReadHeader();
+        }
+
+        while (csvReader.Read())
+        {
+            string[] record;
+
+            try
+            {
+                record = csvReader.Parser.Record;
+            }
+            catch (Exception ex)
+            {
+                var readerException = new ReaderException(csvReader.Context, "An unexpected error occurred.", ex);
+
+                if (csvReader.Configuration.ReadingExceptionOccurred?.Invoke(new ReadingExceptionOccurredArgs(readerException)) ?? true)
+                {
+                    throw readerException;
+                }
+
+                continue;
+            }
+
+            yield return record;
+        }
+    }
 }

CsvHelper.FastDynamic.Performance/ReaderBenchmark.cs

@@ -21,7 +21,7 @@ public ReaderBenchmark()
 
     private readonly string _sampleCsvData;
 
-    [Benchmark]
+    [Benchmark(Baseline = true)]
     public IReadOnlyList<dynamic> GetRecords()
     {
         using var csvReader = new CsvReader(new StringReader(_sampleCsvData), CultureInfo.InvariantCulture);
@@ -44,4 +44,12 @@ public IReadOnlyList<dynamic> GetDynamicRecords()
 
         return csvReader.GetDynamicRecords();
     }
+
+    [Benchmark]
+    public IReadOnlyList<string[]> GetRawRecords()
+    {
+        using var csvReader = new CsvReader(new StringReader(_sampleCsvData), CultureInfo.InvariantCulture);
+
+        return csvReader.GetRawRecords();
+    }
 }

CsvHelper.FastDynamic.Performance/WriterBenchmark.cs

@@ -20,7 +20,7 @@ public WriterBenchmark()
 
     private readonly IReadOnlyList<dynamic> _dynamicCsvData;
 
-    [Benchmark]
+    [Benchmark(Baseline = true)]
     public void WriteRecords_DynamicObject()
     {
         using var csvWriter = new CsvWriter(new StringWriter(), CultureInfo.InvariantCulture);

CsvHelper.FastDynamic.Tests/CsvHelper.FastDynamic.Tests.csproj

@@ -7,8 +7,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
-    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />
+    <PackageReference Include="xunit" Version="2.4.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

CsvHelper.FastDynamic.Tests/CsvReaderTests.cs

@@ -11,7 +11,7 @@ namespace CsvHelper.FastDynamic.Tests;
 public class CsvReaderTests
 {
     [Fact]
-    public void ReadDynamicRecords()
+    public void GetDynamicRecords()
     {
         var csvReader = CreateInMemoryReader();
 
@@ -29,7 +29,7 @@ public void ReadDynamicRecords()
     }
 
     [Fact]
-    public void ReadDynamicRecords_UseIndexer()
+    public void GetDynamicRecords_UseIndexer()
     {
         var csvReader = CreateInMemoryReader();
 
@@ -47,7 +47,7 @@ public void ReadDynamicRecords_UseIndexer()
     }
 
     [Fact]
-    public void ReadDynamicRecords_AsDictionary()
+    public void GetDynamicRecords_AsDictionary()
     {
         var csvReader = CreateInMemoryReader();
 
@@ -67,7 +67,7 @@ public void ReadDynamicRecords_AsDictionary()
     }
 
     [Fact]
-    public void ReadDynamicRecords_WithMissingHeader()
+    public void GetDynamicRecords_WithMissingHeader()
     {
         var csvReader = CreateInMemoryReader_WithMissingHeader();
 
@@ -88,7 +88,7 @@ public void ReadDynamicRecords_WithMissingHeader()
     }
 
     [Fact]
-    public async Task ReadDynamicRecordsAsync()
+    public async Task GetDynamicRecordsAsync()
     {
         var csvReader = CreateInMemoryReader();
 
@@ -106,7 +106,45 @@ public async Task ReadDynamicRecordsAsync()
     }
 
     [Fact]
-    public async Task ReadDynamicRecordsAsync_WithMissingHeader()
+    public async Task GetDynamicRecordsAsync_UseIndexer()
+    {
+        var csvReader = CreateInMemoryReader();
+
+        var records = await csvReader.GetDynamicRecordsAsync();
+
+        Assert.NotNull(records);
+        Assert.Equal(3, records.Count);
+
+        for (var i = 0; i < 3; i++)
+        {
+            Assert.Equal(TestData.CsvRecords[i]["Id"], records[i]["Id"]);
+            Assert.Equal(TestData.CsvRecords[i]["Name"], records[i]["Name"]);
+            Assert.Equal(TestData.CsvRecords[i]["Location"], records[i]["Location"]);
+        }
+    }
+
+    [Fact]
+    public async Task GetDynamicRecordsAsync_AsDictionary()
+    {
+        var csvReader = CreateInMemoryReader();
+
+        var records = (await csvReader.GetDynamicRecordsAsync())
+                      .Cast<IDictionary<string, object>>()
+                      .ToArray();
+
+        Assert.NotNull(records);
+        Assert.Equal(3, records.Length);
+
+        for (var i = 0; i < 3; i++)
+        {
+            Assert.Equal(TestData.CsvRecords[i]["Id"], records[i]["Id"]);
+            Assert.Equal(TestData.CsvRecords[i]["Name"], records[i]["Name"]);
+            Assert.Equal(TestData.CsvRecords[i]["Location"], records[i]["Location"]);
+        }
+    }
+
+    [Fact]
+    public async Task GetDynamicRecordsAsync_WithMissingHeader()
     {
         var csvReader = CreateInMemoryReader_WithMissingHeader();
 

CsvHelper.FastDynamic/CsvHelper.FastDynamic.csproj

@@ -17,7 +17,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="CsvHelper" Version="27.2.1" />
+    <PackageReference Include="CsvHelper" Version="29.0.0" />
   </ItemGroup>
 
   <ItemGroup>

CsvHelper.FastDynamic/CsvReaderExtensions.cs

@@ -33,7 +33,10 @@ public static IEnumerable<dynamic> EnumerateDynamicRecords(this CsvReader csvRea
             {
                 var values = new object[csvReader.HeaderRecord.Length];
 
-                Array.Copy(csvReader.Parser.Record, values, csvReader.HeaderRecord.Length);
+                for (var i = 0; i < csvReader.HeaderRecord.Length; i++)
+                {
+                    values[i] = csvReader.Parser[i];
+                }
 
                 record = new CsvRecord(csvHeader, values);
             }
@@ -91,7 +94,10 @@ public static async IAsyncEnumerable<dynamic> EnumerateDynamicRecordsAsync(this
             {
                 var values = new object[csvReader.HeaderRecord.Length];
 
-                Array.Copy(csvReader.Parser.Record, values, csvReader.HeaderRecord.Length);
+                for (var i = 0; i < csvReader.HeaderRecord.Length; i++)
+                {
+                    values[i] = csvReader.Parser[i];
+                }
 
                 record = new CsvRecord(csvHeader, values);
             }

CsvHelper.FastDynamic/CsvRecord.cs

@@ -105,10 +105,7 @@ object IDictionary<string, object>.this[string key]
 
     int IReadOnlyCollection<KeyValuePair<string, object>>.Count => _values.Count(x => x is not DeadValue);
 
-    object IReadOnlyDictionary<string, object>.this[string key]
-    {
-        get => TryGetValue(key, out var value) ? value : null;
-    }
+    object IReadOnlyDictionary<string, object>.this[string key] => TryGetValue(key, out var value) ? value : null;
 
     bool IReadOnlyDictionary<string, object>.TryGetValue(string key, out object value) => TryGetValue(key, out value);
 

README.md

@@ -35,7 +35,7 @@ foreach (var @record in records)
 }
 ```
 
-### Async CSV Enumerate (.NET Standard 2.1 / C# 8.0)
+### Async CSV Enumerate (.NET Standard 2.1 / C# 8.0 or later)
 
 ```csharp
 using CsvHelper;
@@ -56,34 +56,35 @@ await foreach (var @record in records)
 ### Dynamic record reader
 
 ```
-BenchmarkDotNet=v0.13.1, OS=Windows 10.0.22000
+BenchmarkDotNet=v0.13.2, OS=Windows 11 (10.0.22621.608)
 AMD Ryzen 9 5950X, 1 CPU, 32 logical and 16 physical cores
-.NET SDK=6.0.200
-  [Host]     : .NET 6.0.2 (6.0.222.6406), X64 RyuJIT
-  DefaultJob : .NET 6.0.2 (6.0.222.6406), X64 RyuJIT
+.NET SDK=6.0.401
+  [Host]     : .NET 6.0.9 (6.0.922.41905), X64 RyuJIT AVX2
+  DefaultJob : .NET 6.0.9 (6.0.922.41905), X64 RyuJIT AVX2
 
 
-|               Method |     Mean |   Error |  StdDev |   Gen 0 |   Gen 1 | Allocated |
-|--------------------- |---------:|--------:|--------:|--------:|--------:|----------:|
-|           GetRecords | 834.0 us | 3.04 us | 2.85 us | 36.1328 | 17.5781 |    602 KB |
-| GetDictionaryRecords | 247.4 us | 0.89 us | 0.78 us | 32.7148 | 16.1133 |    538 KB |
-|    GetDynamicRecords | 227.5 us | 0.85 us | 0.80 us | 28.3203 | 13.4277 |    464 KB |
+|               Method |     Mean |   Error |  StdDev | Ratio |    Gen0 |    Gen1 | Allocated | Alloc Ratio |
+|--------------------- |---------:|--------:|--------:|------:|--------:|--------:|----------:|------------:|
+|           GetRecords | 878.3 us | 3.62 us | 3.20 us |  1.00 | 31.2500 | 15.6250 | 510.84 KB |        1.00 |
+| GetDictionaryRecords | 208.0 us | 0.85 us | 0.76 us |  0.24 | 21.7285 | 10.7422 | 355.03 KB |        0.69 |
+|    GetDynamicRecords | 176.4 us | 1.07 us | 0.95 us |  0.20 | 14.4043 |  6.3477 | 237.26 KB |        0.46 |
+|        GetRawRecords | 154.7 us | 1.08 us | 1.01 us |  0.18 | 13.1836 |  5.8594 | 218.98 KB |        0.43 |
 ```
 
 ### Dynamic record writer
 
 ```
-BenchmarkDotNet=v0.13.1, OS=Windows 10.0.22000
+BenchmarkDotNet=v0.13.2, OS=Windows 11 (10.0.22621.608)
 AMD Ryzen 9 5950X, 1 CPU, 32 logical and 16 physical cores
-.NET SDK=6.0.200
-  [Host]     : .NET 6.0.2 (6.0.222.6406), X64 RyuJIT
-  DefaultJob : .NET 6.0.2 (6.0.222.6406), X64 RyuJIT
+.NET SDK=6.0.401
+  [Host]     : .NET 6.0.9 (6.0.922.41905), X64 RyuJIT AVX2
+  DefaultJob : .NET 6.0.9 (6.0.922.41905), X64 RyuJIT AVX2
 
 
-|                            Method |     Mean |   Error |  StdDev |   Gen 0 |  Gen 1 | Allocated |
-|---------------------------------- |---------:|--------:|--------:|--------:|-------:|----------:|
-|        WriteRecords_DynamicObject | 819.2 us | 0.85 us | 0.76 us | 49.8047 | 9.7656 |    822 KB |
-| WriteDynamicRecords_DynamicObject | 455.0 us | 2.22 us | 1.97 us |  7.8125 | 1.4648 |    134 KB |
+|                            Method |     Mean |   Error |  StdDev | Ratio |    Gen0 |   Gen1 | Allocated | Alloc Ratio |
+|---------------------------------- |---------:|--------:|--------:|------:|--------:|-------:|----------:|------------:|
+|        WriteRecords_DynamicObject | 873.9 us | 2.82 us | 2.64 us |  1.00 | 55.6641 | 9.7656 | 914.53 KB |        1.00 |
+| WriteDynamicRecords_DynamicObject | 498.9 us | 2.52 us | 2.36 us |  0.57 | 13.6719 | 2.4414 | 225.84 KB |        0.25 |
 ```
 
 ## Thanks