refactor: char parser (#38)

* refactor: proper classes for char by char parsing
* perf: review structure of if to improve performances
* perf: usage of delegates and lookupTable
* perf: add also lookup for FirstCharOfField
* refactor: change signature of ReadNextRecord

.gitignore

@@ -24,6 +24,9 @@ bld/
 [Oo]bj/
 [Ll]og/
 
+# Performance checks
+[Nn]u[Gg]etPackages/
+
 # Visual Studio 2015/2017 cache/options directory
 .vs/
 # Uncomment if you have tasks that create the project's static files in wwwroot

Directory.Build.props

@@ -1,8 +1,10 @@
 <Project>
 	<PropertyGroup>
-		<!-- By default every projects are packable except Testing projects-->
+		<!-- By default every projects are packable except Testing, Benchmark, Profiler projects-->
 		<IsPackable>true</IsPackable>
 		<IsPackable Condition="$(MSBuildProjectName.EndsWith('Testing'))">false</IsPackable>
+        <IsPackable Condition="$(MSBuildProjectName.EndsWith('Benchmark'))">false</IsPackable>
+        <IsPackable Condition="$(MSBuildProjectName.EndsWith('Profiler'))">false</IsPackable>
 		<DebugType>portable</DebugType>
 	</PropertyGroup>
 

PocketCsvReader.Benchmark/PocketCsvReader.Benchmark.csproj

@@ -19,5 +19,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
   </ItemGroup>
-
+  <PropertyGroup>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
 </Project>

PocketCsvReader.Benchmark/Program.cs

@@ -10,6 +10,6 @@ public class Program
 {
     public static void Main()
     {
-        var summary = BenchmarkRunner.Run<ToDataTable>();
+        var summary = BenchmarkRunner.Run<ToDataReader>();
     }
 }

PocketCsvReader.Benchmark/ToDataReader.cs

@@ -0,0 +1,156 @@
+using System;
+using System.Diagnostics;
+using System.Formats.Asn1;
+using System.Globalization;
+using System.IO;
+using System.Reflection;
+using System.Runtime.Loader;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Configs;
+using BenchmarkDotNet.Environments;
+using BenchmarkDotNet.Jobs;
+using Bogus;
+
+namespace PocketCsvReader.Benchmark;
+
+[MemoryDiagnoser]
+[Config(typeof(CustomConfig))]
+public class ToDataReader
+{
+    private readonly string _filePath = "data/1MBFile.csv";
+
+    [ParamsSource(nameof(Versions))]
+    public string VersionPath { get; set; } = string.Empty;
+
+    public static IEnumerable<string> Versions => Directory.GetDirectories(@"C:\Users\cedri\Projects\PocketCsvReader\NuGetPackages\");
+
+    private Assembly? _csvAssembly;
+
+    //[Params(16_300, 163_000, 1_630_000)]
+    //[Params(16_300, 163_000)]
+    //[Params(16_300)]
+    [Params(1_630_000)]
+    public int recordCount;
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        if (!Directory.Exists("data"))
+            Directory.CreateDirectory("data");
+
+        var faker = new Faker<CustomerRecord>()
+            .CustomInstantiator(static f => new CustomerRecord(
+                f.Name.FirstName(),
+                f.Name.LastName(),
+                f.PickRandom(new[] { "Male", "Female" }),
+                f.Date.Past(50, DateTime.Now.AddYears(-18)),
+                f.Date.Recent(365).Year,
+                f.Date.Month().ToString(CultureInfo.CurrentCulture),
+                f.Finance.Amount(50, 500)
+            ))
+            .RuleFor(p => p.Year, (f, p) => p.DateOfBirth.Year)
+            .RuleFor(p => p.Month, (f, p) => p.DateOfBirth.ToString("MMMM", CultureInfo.CurrentCulture));
+
+
+        // Generate the list of records
+        var records = faker.Generate(recordCount);
+
+        // Write the data to CSV
+        using (var writer = new StreamWriter(_filePath))
+        {
+            foreach (var record in records)
+                writer.WriteLine($"{record.Firstname},{record.Lastname},{record.Gender},{record.DateOfBirth},{record.Year},{record.Month},{record.TotalOrder}");
+        }
+
+        Console.WriteLine($"CSV file generated at: {_filePath}");
+        Console.WriteLine($"CSV file generated with size: {new FileInfo(_filePath).Length}");
+    }
+
+    [Benchmark]
+    public void ReadCsvFile()
+    {
+        _csvAssembly = LoadPocketCsvReader(VersionPath);
+        ReadFile(_filePath, _csvAssembly!);
+    }
+
+
+    private void LogResults(string version, long memoryUsed, long workingSetUsed)
+    {
+        string logFile = "BenchmarkResults.txt";
+        File.AppendAllText(logFile, $"Version: {version}, Memory Used (GC): {memoryUsed}, Memory Used (Working Set): {workingSetUsed}{Environment.NewLine}");
+    }
+
+    private void ReadFile(string filePath, Assembly csvAssembly)
+    {
+        var csvReaderType = csvAssembly.GetType("PocketCsvReader.CsvReader")!;
+        var csvProfileType = csvAssembly.GetType("PocketCsvReader.CsvProfile")!;
+
+        var csvProfile = Activator.CreateInstance(csvProfileType, ',', '\"', "\r\n", false);
+        dynamic csvReader = Activator.CreateInstance(csvReaderType, csvProfile)!;
+
+        using (var stream = new FileStream(filePath, FileMode.Open))
+        {
+            using var reader = csvReader.ToDataReader(stream);
+            while (reader.Read())
+            {
+                // Do nothing
+            }
+        }
+    }
+
+    private void MeasureMemory(Action action, string version)
+    {
+        GC.Collect();
+        GC.WaitForPendingFinalizers();
+        GC.Collect();
+
+        long memoryBefore = GC.GetTotalMemory(true);
+        var process = Process.GetCurrentProcess();
+        long workingSetBefore = process.WorkingSet64;
+
+        action(); // Run the CSV read action
+
+        process.Refresh();
+        long workingSetAfter = process.WorkingSet64;
+        long memoryAfter = GC.GetTotalMemory(false);
+
+        long gcMemoryUsed = memoryAfter - memoryBefore;
+        long workingSetMemoryUsed = workingSetAfter - workingSetBefore;
+
+        Console.WriteLine($"Memory Used (GC): {gcMemoryUsed} bytes");
+        Console.WriteLine($"Memory Used (Working Set): {workingSetMemoryUsed} bytes");
+
+        LogResults(version, gcMemoryUsed, workingSetMemoryUsed);
+    }
+
+    private Assembly LoadPocketCsvReader(string versionPath)
+    {
+        string dllPath = Path.Combine(versionPath, "PocketCsvReader.dll");
+        if (!File.Exists(dllPath))
+        {
+            throw new FileNotFoundException($"DLL not found: {dllPath}");
+        }
+
+        // Use a custom AssemblyLoadContext to load the assembly
+        var context = new AssemblyLoadContext("PocketCsvReaderContext", isCollectible: true);
+        return context.LoadFromAssemblyPath(dllPath);
+    }
+
+    private class CustomConfig : ManualConfig
+    {
+        public CustomConfig()
+        {
+            foreach (var versionPath in ToDataReader.Versions)
+            {
+                var versionName = Path.GetFileName(versionPath);
+
+                // Create a specific job for each version
+                AddJob(Job.Default
+                    .WithRuntime(CoreRuntime.Core80)
+                    .WithWarmupCount(1)    // 1 warm-up iteration
+                    .WithIterationCount(5) // 5 actual iterations
+                ); // Identify the job by version
+            }
+        }
+    }
+}

PocketCsvReader.Profiler/PocketCsvReader.Profiler.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\PocketCsvReader.Testing\PocketCsvReader.Testing.csproj" />
+    <ProjectReference Include="..\PocketCsvReader\PocketCsvReader.csproj" />
+  </ItemGroup>
+  <PropertyGroup>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
+</Project>

PocketCsvReader.Profiler/Program.cs

@@ -0,0 +1,5 @@
+// See https://aka.ms/new-console-template for more information
+using PocketCsvReader.Testing;
+
+var test = new CsvDataReaderTest();
+test.Read_TestData_Successful(40_000, false);

PocketCsvReader.Testing/FieldParserTest.cs

@@ -35,7 +35,7 @@ public void ReadField_Empty_CorrectString(string item, string result)
     }
 
     [Test]
-    [TestCase("(null)", null)] //Parse (null) to a real null value
+    [TestCase("(null)", null)] //InternalParse (null) to a real null value
     public void ReadField_Null_CorrectString(string item, string result)
     {
         Span<char> buffer = stackalloc char[64];

PocketCsvReader.Testing/PocketCsvReader.Testing.csproj

@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
   <ItemGroup>
     <None Remove="Resources\Ansi.csv" />
     <None Remove="Resources\Utf16-BE.csv" />