Add cancellation and progress reporting to CSV reader

Introduces CancellationToken support and progress reporting via CsvReaderOptions for Dataplat.Dbatools.Csv. Benchmarks now compare against Sep, Sylvan.Data.Csv, and CsvHelper. Documentation and changelog updated to reflect new features and honest performance positioning. Version bumped to 1.1.0.

Author: potatoqualitee

benchmarks/CsvBenchmarks/CsvBenchmarks.csproj

@@ -12,6 +12,10 @@
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" Version="0.14.0" />
     <PackageReference Include="Microsoft.Data.SqlClient" Version="6.0.2" />
+    <!-- Competitor CSV libraries for benchmarking -->
+    <PackageReference Include="Sep" Version="0.12.0" />
+    <PackageReference Include="Sylvan.Data.Csv" Version="1.4.0" />
+    <PackageReference Include="CsvHelper" Version="33.0.1" />
   </ItemGroup>
 
   <ItemGroup>

benchmarks/CsvBenchmarks/Program.cs

@@ -8,7 +8,14 @@
 using BenchmarkDotNet.Exporters;
 using System.Data;
 using System.Text;
+using System.Globalization;
 using Dataplat.Dbatools.Csv.Reader;
+using nietras.SeparatedValues;
+using CsvHelper;
+using CsvHelper.Configuration;
+
+// Alias to avoid ambiguity with Sylvan and CsvHelper
+using DataplatCsvReader = Dataplat.Dbatools.Csv.Reader.CsvDataReader;
 
 namespace CsvBenchmarks;
 
@@ -122,7 +129,7 @@ private void GenerateCsv(string path, int rows, int cols, bool quoteAll)
     public int Dataplat_Small()
     {
         int count = 0;
-        using var reader = new CsvDataReader(_smallCsvPath);
+        using var reader = new DataplatCsvReader(_smallCsvPath);
         while (reader.Read())
         {
             count++;
@@ -153,7 +160,7 @@ public int LumenWorks_Small()
     public int Dataplat_Medium()
     {
         int count = 0;
-        using var reader = new CsvDataReader(_mediumCsvPath);
+        using var reader = new DataplatCsvReader(_mediumCsvPath);
         while (reader.Read())
         {
             count++;
@@ -184,7 +191,7 @@ public int LumenWorks_Medium()
     public int Dataplat_Large()
     {
         int count = 0;
-        using var reader = new CsvDataReader(_largeCsvPath);
+        using var reader = new DataplatCsvReader(_largeCsvPath);
         while (reader.Read())
         {
             count++;
@@ -215,7 +222,7 @@ public int LumenWorks_Large()
     public int Dataplat_Wide()
     {
         int count = 0;
-        using var reader = new CsvDataReader(_wideCsvPath);
+        using var reader = new DataplatCsvReader(_wideCsvPath);
         while (reader.Read())
         {
             count++;
@@ -246,7 +253,7 @@ public int LumenWorks_Wide()
     public int Dataplat_Quoted()
     {
         int count = 0;
-        using var reader = new CsvDataReader(_quotedCsvPath);
+        using var reader = new DataplatCsvReader(_quotedCsvPath);
         while (reader.Read())
         {
             count++;
@@ -270,6 +277,138 @@ public int LumenWorks_Quoted()
         return count;
     }
 
+    // ===================== Modern Library Comparisons (Medium) =====================
+
+    [Benchmark(Description = "Sep-Medium")]
+    [BenchmarkCategory("Modern")]
+    public int Sep_Medium()
+    {
+        int count = 0;
+        using var reader = Sep.Reader().FromFile(_mediumCsvPath);
+        foreach (var row in reader)
+        {
+            count++;
+            _ = row[0].ToString();
+        }
+        return count;
+    }
+
+    [Benchmark(Description = "Sylvan-Medium")]
+    [BenchmarkCategory("Modern")]
+    public int Sylvan_Medium()
+    {
+        int count = 0;
+        using var textReader = new StreamReader(_mediumCsvPath);
+        using var reader = Sylvan.Data.Csv.CsvDataReader.Create(textReader);
+        while (reader.Read())
+        {
+            count++;
+            _ = reader.GetString(0);
+        }
+        return count;
+    }
+
+    [Benchmark(Description = "CsvHelper-Medium")]
+    [BenchmarkCategory("Modern")]
+    public int CsvHelper_Medium()
+    {
+        int count = 0;
+        var config = new CsvConfiguration(CultureInfo.InvariantCulture)
+        {
+            HasHeaderRecord = true
+        };
+        using var textReader = new StreamReader(_mediumCsvPath);
+        using var csv = new CsvHelper.CsvReader(textReader, config);
+        csv.Read();
+        csv.ReadHeader();
+        while (csv.Read())
+        {
+            count++;
+            _ = csv.GetField(0);
+        }
+        return count;
+    }
+
+    [Benchmark(Description = "Dataplat-Medium-Modern")]
+    [BenchmarkCategory("Modern")]
+    public int Dataplat_Medium_Modern()
+    {
+        int count = 0;
+        using var reader = new Dataplat.Dbatools.Csv.Reader.CsvDataReader(_mediumCsvPath);
+        while (reader.Read())
+        {
+            count++;
+            _ = reader.GetValue(0);
+        }
+        return count;
+    }
+
+    // ===================== Modern Library Comparisons (Large) =====================
+
+    [Benchmark(Description = "Sep-Large")]
+    [BenchmarkCategory("ModernLarge")]
+    public int Sep_Large()
+    {
+        int count = 0;
+        using var reader = Sep.Reader().FromFile(_largeCsvPath);
+        foreach (var row in reader)
+        {
+            count++;
+            _ = row[0].ToString();
+        }
+        return count;
+    }
+
+    [Benchmark(Description = "Sylvan-Large")]
+    [BenchmarkCategory("ModernLarge")]
+    public int Sylvan_Large()
+    {
+        int count = 0;
+        using var textReader = new StreamReader(_largeCsvPath);
+        using var reader = Sylvan.Data.Csv.CsvDataReader.Create(textReader);
+        while (reader.Read())
+        {
+            count++;
+            _ = reader.GetString(0);
+        }
+        return count;
+    }
+
+    [Benchmark(Description = "CsvHelper-Large")]
+    [BenchmarkCategory("ModernLarge")]
+    public int CsvHelper_Large()
+    {
+        int count = 0;
+        var config = new CsvConfiguration(CultureInfo.InvariantCulture)
+        {
+            HasHeaderRecord = true
+        };
+        using var textReader = new StreamReader(_largeCsvPath);
+        using var csv = new CsvHelper.CsvReader(textReader, config);
+        csv.Read();
+        csv.ReadHeader();
+        while (csv.Read())
+        {
+            count++;
+            _ = csv.GetField(0);
+        }
+        return count;
+    }
+
+    [Benchmark(Description = "Dataplat-Large-Modern")]
+    [BenchmarkCategory("ModernLarge")]
+    public int Dataplat_Large_Modern()
+    {
+        int count = 0;
+        using var reader = new Dataplat.Dbatools.Csv.Reader.CsvDataReader(_largeCsvPath);
+        while (reader.Read())
+        {
+            count++;
+            _ = reader.GetValue(0);
+        }
+        return count;
+    }
+
     // ===================== All Values Access Benchmarks =====================
 
     [Benchmark(Description = "Dataplat-AllValues")]
@@ -278,7 +417,7 @@ public int Dataplat_AllValues()
     {
         int count = 0;
         var options = new CsvReaderOptions { BufferSize = 65536 };
-        using var reader = new CsvDataReader(_mediumCsvPath, options);
+        using var reader = new DataplatCsvReader(_mediumCsvPath, options);
         object[] values = new object[reader.FieldCount];
         while (reader.Read())
         {