App/Controllers/ImageController.cs

@@ -6,11 +6,7 @@ namespace StitchATon2.App.Controllers;
 
 public static class ImageController
 {
-    public static async Task GenerateImage(
+    public static async Task GenerateImage(HttpResponse response, GenerateImageDto dto, TileManager tileManager)
-        HttpResponse response,
-        GenerateImageDto dto,
-        TileManager tileManager,
-        CancellationToken cancellationToken)
     {
         if (dto.GetErrors() is { Count: > 0 } errors)
         {
@@ -18,7 +14,7 @@ public static class ImageController
             response.ContentType = "text/json";
             var errorBody = JsonSerializer.Serialize(errors, AppJsonSerializerContext.Default.DictionaryStringListString);
             response.ContentLength = errorBody.Length;
-            await response.WriteAsync(errorBody, cancellationToken: cancellationToken);
+            await response.WriteAsync(errorBody);
             await response.CompleteAsync();
             return;
         }
@@ -26,19 +22,14 @@ public static class ImageController
         response.StatusCode = 200;
         response.ContentType = "image/png";
 
-        Console.WriteLine($"Generate image for {dto}");
-
         await tileManager
             .CreateSection(dto)
-            .WriteToPipe(response.BodyWriter, dto.OutputScale, cancellationToken);
+            .WriteToStream(response.Body, dto.OutputScale);
         
         await response.CompleteAsync();
     }
     
-    public static async Task GenerateRandomImage(
+    public static async Task GenerateRandomImage(HttpResponse response, TileManager tileManager)
-        HttpResponse response,
-        TileManager tileManager,
-        CancellationToken cancellationToken)
     {
         response.StatusCode = 200;
         response.ContentType = "image/png";
@@ -56,7 +47,7 @@ public static class ImageController
         var scale = float.Clamp(480f / int.Max(section.Width, section.Height), 0.01f, 1f);
         Console.WriteLine($"Generate random image for {coordinatePair} scale: {scale}");
         
-        await section.WriteToPipe(response.BodyWriter, scale, cancellationToken);
+        await section.WriteToStream(response.Body, scale);
         await response.CompleteAsync();
     }
 }

App/Models/GenerateImageDto.cs

@@ -69,9 +69,4 @@ public class GenerateImageDto
             yield return (fieldName, $"{fieldName} must be less than or equal to {max}.");
         }
     }
-
-    public override string ToString()
-    {
-        return $"CoordinatePair: {CanvasRect}, Crop: [{CropOffset![0]} {CropOffset[1]} {CropSize![0]} {CropSize[1]}], OutputScale: {OutputScale}";
-    }
 }

App/Program.cs

@@ -5,7 +5,7 @@ using StitchATon2.Domain;
 
 var builder = WebApplication.CreateSlimBuilder(args);
 
-var tileManager = new TileManager(Configuration.Default);
+using var tileManager = new TileManager(Configuration.Default);
 builder.Services.AddSingleton(tileManager);
 
 builder.Services.ConfigureHttpJsonOptions(options =>

App/StitchATon2.App.csproj

@@ -1,12 +1,15 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
     <PropertyGroup>
-        <TargetFramework>net9.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
         <Nullable>enable</Nullable>
         <ImplicitUsings>enable</ImplicitUsings>
         <InvariantGlobalization>true</InvariantGlobalization>
-        <RootNamespace>StitchATon2.App</RootNamespace>
         <PublishAot>true</PublishAot>
+        <RootNamespace>StitchATon2.App</RootNamespace>
+
+<!--        <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>-->
+<!--        <CompilerGeneratedFilesOutputPath>Generated</CompilerGeneratedFilesOutputPath>-->
     </PropertyGroup>
 
     <ItemGroup>

App/Utils.cs

@@ -1,4 +1,3 @@
-using System.IO.Pipelines;
 using StitchATon2.App.Models;
 using StitchATon2.Domain;
 using StitchATon2.Domain.ImageCreators;
@@ -15,23 +14,9 @@ public static class Utils
             dto.CropSize![0],
             dto.CropSize![1]);
 
-    public static async Task WriteToStream(
+    public static async Task WriteToStream(this GridSection section, Stream stream, float? scale)
-        this GridSection section,
-        Stream stream,
-        float? scale,
-        CancellationToken cancellationToken = default)
     {
-        using var imageCreator = new DangerousImageCreator(section);
+        var imageCreator = new ImageCreator(section);
-        await imageCreator.WriteToStream(stream, scale!.Value, cancellationToken);
+        await imageCreator.WriteToStream(stream, scale!.Value);
-    }
-
-    public static async Task WriteToPipe(
-        this GridSection section,
-        PipeWriter pipeWriter,
-        float? scale,
-        CancellationToken cancellationToken = default)
-    {
-        using var imageCreator = new DangerousImageCreator(section);
-        await imageCreator.WriteToPipe(pipeWriter, scale!.Value, cancellationToken);
     }
 }

Domain/Configuration.cs

@@ -20,20 +20,25 @@ public class Configuration
     
     public int TileCount => Columns * Rows;
 
+    public required int ImageCacheCapacity { get; init; }
+    public required int IntegralCacheCapacity { get; init; }
+
     public static Configuration Default
     {
         get
         {
-            var assetPath = Environment.GetEnvironmentVariable("ASSET_PATH_RO");
+            var assetPath = Environment.GetEnvironmentVariable("ASSET_PATH_RO")!;
             var cachePath = Path.Combine(Path.GetTempPath(), "d42df2a2-60ac-4dc3-a6b9-d4c04f2e08e6");
             return new Configuration
             {
-                AssetPath = assetPath!,
+                AssetPath = assetPath,
                 CachePath = cachePath,
                 Columns = 55,
                 Rows = 31,
                 Width = 720,
                 Height = 720,
+                ImageCacheCapacity = 5,
+                IntegralCacheCapacity = 10,
             };
         }
     }

Domain/GridSection.cs

@@ -47,10 +47,5 @@ public class GridSection
         (var rowOffset, OffsetY) = Math.DivRem(y0, config.Height);
         
         Origin = tileManager.GetTile(col0 + columnOffset, row0 + rowOffset);
-        Console.Write($"Origin: {Origin.Coordinate} ({Origin.Column}, {Origin.Row}) ");
-        Console.Write($"Tile offset: [{columnOffset} {rowOffset}] ");
-        Console.Write($"Pixel offset: [{OffsetX} {OffsetY}] ");
-        Console.Write($"Size: [{Width}x{Height}]");
-        Console.WriteLine();
     }
 }

Domain/ImageCreators/DangerousImageCreator.cs

@@ -1,234 +0,0 @@
-using System.IO.Pipelines;
-using System.Runtime.CompilerServices;
-using SixLabors.ImageSharp.PixelFormats;
-using StitchATon2.Infra;
-using StitchATon2.Infra.Buffers;
-using StitchATon2.Infra.Encoders;
-using StitchATon2.Infra.Synchronization;
-
-namespace StitchATon2.Domain.ImageCreators;
-
-public sealed class DangerousImageCreator : IDisposable
-{
-    private readonly GridSection _section;
-    private readonly IBuffer<Int32Pixel> _mmfReadBuffer;
-
-    private int FullWidth => _section.TileManager.Configuration.FullWidth;
-    private int FullHeight => _section.TileManager.Configuration.FullHeight;
-
-    private int OffsetX => _section.OffsetX;
-    private int OffsetY => _section.OffsetY;
-
-    private int Width => _section.Width;
-    private int Height => _section.Height;
-
-    private int TileWidth => _section.TileManager.Configuration.Width;
-    private int TileHeight => _section.TileManager.Configuration.Height;
-    private Tile TileOrigin => _section.Origin;
-    
-    private int RightmostPixelIndex => _section.TileManager.Configuration.RightTileIndex;
-    private int BottomPixelIndex => _section.TileManager.Configuration.BottomTileIndex;
-    
-    private TileManager TileManager => _section.TileManager;
-
-    public DangerousImageCreator(GridSection section)
-    {
-        _section = section;
-        _mmfReadBuffer = MemoryAllocator.Allocate<Int32Pixel>(TileWidth);
-    }
-    
-    ~DangerousImageCreator() => Dispose();
-
-    private Task Create(float scale, Action<IBuffer<byte>> writeRowCallback, CancellationToken cancellationToken)
-    {
-        var scaleFactor = MathF.ReciprocalEstimate(scale);
-        var targetWidth = (int)(Width / scaleFactor);
-        var targetHeight = (int)(Height / scaleFactor);
-        if (targetHeight == 0 || targetWidth == 0)
-            return Task.CompletedTask;
-
-        using var xLookup = Utils.BoundsMatrix(scaleFactor, targetWidth, FullWidth, OffsetX);
-        using var yLookup = Utils.BoundsMatrix(scaleFactor, targetHeight, FullHeight, OffsetY);
-
-        using var yStartMap = MemoryAllocator.Allocate<Int32Pixel>(targetWidth + 1);
-        using var yEndMap = MemoryAllocator.Allocate<Int32Pixel>(targetWidth + 1);
-        
-        var outputBufferSize = targetWidth * Unsafe.SizeOf<Rgb24>();
-        
-        // Use pixel referencing to eliminate type casting
-        var pxInt32 = Int32Pixel.Zero;
-        ref var px = ref pxInt32;
-        ref var rChannel = ref Unsafe.As<Int32Pixel, byte>(ref px);
-        ref var gChannel = ref Unsafe.Add(ref rChannel, 4);
-        ref var bChannel = ref Unsafe.Add(ref rChannel, 8);
-
-        var taskQueue = TaskHelper.SynchronizedTaskFactory.StartNew(() => { }, cancellationToken);
-        
-        for (var y = 1; y <= targetHeight; y++)
-        {
-            var yStart = yLookup[y - 1];
-            var yEnd = yLookup[y];
-            
-            var (localRow0, localOffsetY0) = int.DivRem(yStart, TileHeight);
-            MapRow(localRow0, localOffsetY0, xLookup, targetWidth + 1, yStartMap);
-            
-            var (localRow1, localOffsetY1) = int.DivRem(yEnd, TileHeight);
-            MapRow(localRow1, localOffsetY1, xLookup, targetWidth + 1, yEndMap);
-            
-            // Cross row
-            if (localRow0 != localRow1)
-                MapRow(localRow0, BottomPixelIndex, xLookup, targetWidth + 1, yEndMap, true);
-            
-            var outputBuffer = MemoryAllocator.Allocate<byte>(outputBufferSize);
-            ref var outputChannel = ref outputBuffer.Span[0];
-            var boxHeight = yEnd - yStart;
-            
-            for (int x1 = 1, x0 = 0; x1 <= targetWidth; x0 = x1++)
-            {
-                var xStart = xLookup[x1 - 1];
-                var xEnd = xLookup[x1];
-
-                px = yEndMap[x1];
-                px += yStartMap[x0];
-                px -= yEndMap[x0];
-                px -= yStartMap[x1];
-                px /= Math.Max(1, (xEnd - xStart) * boxHeight);
-                
-                outputChannel = rChannel;
-                outputChannel = ref Unsafe.AddByteOffset(ref outputChannel, 1);
-                
-                outputChannel = gChannel;
-                outputChannel = ref Unsafe.AddByteOffset(ref outputChannel, 1);
-                
-                outputChannel = bChannel;
-                outputChannel = ref Unsafe.AddByteOffset(ref outputChannel, 1);
-            }
-
-            if (cancellationToken.IsCancellationRequested)
-            {
-                outputBuffer.Dispose();
-                return Task.FromCanceled(cancellationToken);
-            }
-            
-            cancellationToken.Register(outputBuffer.Dispose);
-            taskQueue = taskQueue
-                .ContinueWith(
-                    _ => writeRowCallback.Invoke(outputBuffer),
-                    cancellationToken,
-                    TaskContinuationOptions.OnlyOnRanToCompletion,
-                    TaskScheduler.Current);
-        }
-
-        return taskQueue;
-    }
-
-    public async Task WriteToPipe(PipeWriter outputPipe, float scale, CancellationToken cancellationToken = default)
-    {
-        var scaleFactor = MathF.ReciprocalEstimate(scale);
-        var targetWidth = (int)(Width / scaleFactor);
-        var targetHeight = (int)(Height / scaleFactor);
-        if (targetHeight == 0 || targetWidth == 0)
-            return;
-        
-        var encoder = new PngPipeEncoder(outputPipe, targetWidth, targetHeight);
-        encoder.WriteHeader();
-        
-        await Create(scale, 
-            output => encoder
-                .WriteDataAsync(output, cancellationToken: cancellationToken)
-                .Wait(cancellationToken),
-            cancellationToken);
-        
-        await encoder.WriteEndOfFileAsync(cancellationToken);
-    }
-
-    public async Task WriteToStream(Stream outputStream, float scale, CancellationToken cancellationToken = default)
-    {
-        var scaleFactor = MathF.ReciprocalEstimate(scale);
-        var targetWidth = (int)(Width / scaleFactor);
-        var targetHeight = (int)(Height / scaleFactor);
-        if (targetHeight == 0 || targetWidth == 0)
-            return;
-        
-        var encoder = new PngStreamEncoder(outputStream, targetWidth, targetHeight);
-        await encoder.WriteHeader(cancellationToken);
-        
-        await Create(scale, 
-            output => encoder
-                .WriteDataAsync(output, cancellationToken: cancellationToken)
-                .Wait(cancellationToken),
-            cancellationToken);
-        
-        await encoder.WriteEndOfFileAsync(cancellationToken);
-    }
-    
-    private void MapRow(
-        int rowOffset,
-        int yOffset,
-        IBuffer<int> boundsMatrix,
-        int count,
-        IBuffer<Int32Pixel> destination,
-        bool appendMode = false)
-    {
-        var currentTile = TileManager.TryGetAdjacent(TileOrigin, 0, rowOffset);
-        if (currentTile == null)
-        {
-            if (appendMode) return;
-            for (var i = 0; i < count; i++)
-                destination[i] = Int32Pixel.Zero;
-
-            return;
-        }
-        
-        var sourceMap = boundsMatrix.Span[..count];
-        var xAdder = Int32Pixel.Zero;
-        var xOffset = 0;
-        var written = 0;
-        var destinationSpan = destination.Span;
-        var readBufferSpan = _mmfReadBuffer.Span;
-        
-        while (true)
-        {
-            currentTile.Integral.Acquire(yOffset, readBufferSpan);
-            int localX;
-
-            if (appendMode)
-            {
-                while (written < sourceMap.Length && (localX = sourceMap[written] - xOffset) < TileWidth)
-                {
-                    destinationSpan[written] += readBufferSpan[localX];
-                    destinationSpan[written] += xAdder;
-                    written++;
-                }
-            }
-            else
-            {
-                while (written < sourceMap.Length && (localX = sourceMap[written] - xOffset) < TileWidth)
-                {
-                    destinationSpan[written] = readBufferSpan[localX];
-                    destinationSpan[written] += xAdder;
-                    written++;
-                }
-            }
-            
-            if (written >= sourceMap.Length)
-                break;
-            
-            currentTile = TileManager.TryGetAdjacent(currentTile, 1, 0);
-            if (currentTile == null)
-            {
-                destinationSpan[written] = destinationSpan[written - 1];
-                break;
-            }
-
-            xAdder += readBufferSpan[RightmostPixelIndex];
-            xOffset += TileWidth;
-        }
-    }
-
-    public void Dispose()
-    {
-        _mmfReadBuffer.Dispose();
-        GC.SuppressFinalize(this);
-    }
-}

Domain/ImageCreators/ImageCreator.cs

@@ -0,0 +1,155 @@
+using System.Buffers;
+using System.Runtime.CompilerServices;
+using SixLabors.ImageSharp.PixelFormats;
+using StitchATon2.Infra;
+using StitchATon2.Infra.Buffers;
+using StitchATon2.Infra.Encoders;
+
+namespace StitchATon2.Domain.ImageCreators;
+
+public class ImageCreator
+{
+    private readonly GridSection _section;
+
+    private int FullWidth => _section.TileManager.Configuration.FullWidth;
+    private int FullHeight => _section.TileManager.Configuration.FullHeight;
+
+    private int OffsetX => _section.OffsetX;
+    private int OffsetY => _section.OffsetY;
+
+    private int Width => _section.Width;
+    private int Height => _section.Height;
+
+    private int TileWidth => _section.TileManager.Configuration.Width;
+    private int TileHeight => _section.TileManager.Configuration.Height;
+    private Tile TileOrigin => _section.Origin;
+    
+    private int RightmostPixelIndex => _section.TileManager.Configuration.RightTileIndex;
+    private int BottomPixelIndex => _section.TileManager.Configuration.BottomTileIndex;
+    
+    private TileManager TileManager => _section.TileManager;
+
+    private readonly Int32Pixel[] _mmfReadBuffer;
+
+    public ImageCreator(GridSection section)
+    {
+        _section = section;
+        _mmfReadBuffer = ArrayPool<Int32Pixel>.Shared.Rent(TileWidth);
+    }
+    
+    public async Task WriteToStream(Stream writableStream, float scale)
+    {
+        var scaleFactor = MathF.ReciprocalEstimate(scale);
+        var targetWidth = (int)(Width / scaleFactor);
+        var targetHeight = (int)(Height / scaleFactor);
+        
+        var encoder = new PngStreamEncoder(writableStream, targetWidth, targetHeight);
+        await encoder.WriteHeader();
+
+        var outputBufferSize = targetWidth * Unsafe.SizeOf<Rgb24>();
+        using var outputBuffer = MemoryAllocator.AllocateManaged<byte>(outputBufferSize);
+        
+        using var xLookup = Utils.BoundsMatrix(scaleFactor, targetWidth, FullWidth, OffsetX);
+        using var yLookup = Utils.BoundsMatrix(scaleFactor, targetHeight, FullHeight, OffsetY);
+
+        using var yStartMap = MemoryAllocator.Allocate<Int32Pixel>(targetWidth);
+        using var yEndMap = MemoryAllocator.Allocate<Int32Pixel>(targetWidth);
+
+        var yStart = OffsetY;
+        Task? outputTask = null;
+        for (var y = 0; y < targetHeight; y++)
+        {
+            var yEnd = yLookup[y];
+            
+            var (localRow0, localOffsetY0) = int.DivRem(yStart, TileHeight);
+            MapRow(localRow0, localOffsetY0, xLookup.Span[..targetWidth], yStartMap);
+            
+            var (localRow1, localOffsetY1) = int.DivRem(yEnd, TileHeight);
+            MapRow(localRow1, localOffsetY1, xLookup.Span[..targetWidth], yEndMap);
+            
+            if (localRow0 != localRow1)
+            {
+                MapRowAppend(localRow0, BottomPixelIndex, xLookup.Span[..targetWidth], yEndMap);
+            }
+
+            if(outputTask != null)
+                await outputTask;
+
+            int xStart = OffsetX, x0 = 0;
+            for (int x1 = 0, i = 0; x1 < targetWidth; x1++)
+            {
+                var xEnd = xLookup[x1];
+
+                var pixel = yEndMap[x1];
+                pixel += yStartMap[x0];
+                pixel -= yEndMap[x0];
+                pixel -= yStartMap[x1];
+                
+                pixel /= Math.Max(1, (xEnd - xStart) * (yEnd - yStart));
+                outputBuffer.Memory.Span[i++] = (byte)pixel.R;
+                outputBuffer.Memory.Span[i++] = (byte)pixel.G;
+                outputBuffer.Memory.Span[i++] = (byte)pixel.B;
+                
+                xStart = xEnd;
+                x0 = x1;
+            }
+            
+            outputTask = encoder.WriteData(outputBuffer.Memory[..outputBufferSize]);
+            yStart = yEnd;
+        }
+
+        await encoder.WriteEndOfFile();
+    }
+    
+    private void MapRow(int rowOffset, int yOffset, Span<int> sourceMap, IBuffer<Int32Pixel> destination)
+    {
+        var currentTile = TileManager.GetAdjacent(TileOrigin, 0, rowOffset);
+        var xAdder = Int32Pixel.Zero;
+        var xOffset = 0;
+        var written = 0;
+        while (true)
+        {
+            currentTile.Integral.Acquire(yOffset, _mmfReadBuffer);
+            int localX;
+            while (written < sourceMap.Length && (localX = sourceMap[written] - xOffset) < TileWidth)
+            {
+                destination.Span[written] = _mmfReadBuffer[localX];
+                destination.Span[written] += xAdder;
+                written++;
+            }
+
+            if (written >= sourceMap.Length)
+                break;
+
+            xAdder += _mmfReadBuffer[RightmostPixelIndex];
+            xOffset += TileWidth;
+            currentTile = TileManager.GetAdjacent(currentTile, 1, 0);
+        }
+    }
+
+    private void MapRowAppend(int rowOffset, int yOffset, Span<int> sourceMap, IBuffer<Int32Pixel> destination)
+    {
+        var currentTile = TileManager.GetAdjacent(TileOrigin, 0, rowOffset);
+        var xAdder = Int32Pixel.Zero;
+        var xOffset = 0;
+        var written = 0;
+        while (true)
+        {
+            currentTile.Integral.Acquire(yOffset, _mmfReadBuffer);
+            int localX;
+            while (written < sourceMap.Length && (localX = sourceMap[written] - xOffset) < TileWidth)
+            {
+                destination.Span[written] += _mmfReadBuffer[localX];
+                destination.Span[written] += xAdder;
+                written++;
+            }
+
+            if (written >= sourceMap.Length)
+                break;
+
+            xAdder += _mmfReadBuffer[RightmostPixelIndex];
+            xOffset += TileWidth;
+            currentTile = TileManager.GetAdjacent(currentTile, 1, 0);
+        }
+    }
+}

Domain/StitchATon2.Domain.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net9.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
     </PropertyGroup>

Domain/TileManager.cs

@@ -5,26 +5,29 @@ using StitchATon2.Infra.Buffers;
 
 namespace StitchATon2.Domain;
 
-public sealed class TileManager
+public sealed class TileManager : IDisposable
 {
-    private readonly Tile[] _tiles;
+    private readonly IMemoryOwner<Tile> _tiles;
     
     public Configuration Configuration { get; }
 
     public TileManager(Configuration config)
     {
         Configuration = config;
-        _tiles = new Tile[Configuration.TileCount];
+        _tiles = MemoryAllocator.AllocateManaged<Tile>(config.TileCount);
+        var tilesSpan = _tiles.Memory.Span;
         for (var id = 0; id < config.TileCount; id++)
-            _tiles[id] = CreateTile(id);
+            tilesSpan[id] = CreateTile(id);
         
         Console.WriteLine("Tile manager created");
     }
     
+    ~TileManager() => Dispose();
+
     private Tile CreateTile(int id)
     {
         var (row, column) = int.DivRem(id, Configuration.Columns);
-        var coordinate = $"{Utils.GetSbsNotationRow(++row)}{++column}";
+        var coordinate = $"{Utils.GetSBSNotation(++row)}{++column}";
         return new Tile
         {
             Id = id,
@@ -44,14 +47,14 @@ public sealed class TileManager
     private int GetId(int column, int row) => column - 1 + (row - 1) * Configuration.Columns;
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public Tile GetTile(int id) => _tiles[id];
+    public Tile GetTile(int id) => _tiles.Memory.Span[id];
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public Tile GetTile(int column, int row) => GetTile(GetId(column, row));
 
     public Tile GetTile(string coordinate)
     {
-        var (column, row) = Utils.GetSbsNotationCoordinate(coordinate);
+        var (column, row) = Utils.GetSBSCoordinate(coordinate);
         return GetTile(column, row);
     }
     
@@ -96,4 +99,10 @@ public sealed class TileManager
             cropY,
             cropWidth,
             cropHeight);
+
+    public void Dispose()
+    {
+        _tiles.Dispose();
+        GC.SuppressFinalize(this);
+    }
 }

Domain/Utils.cs

@@ -9,7 +9,7 @@ namespace StitchATon2.Domain;
 public static class Utils
 {
     [Pure]
-    public static string GetSbsNotationRow(int row)
+    public static string GetSBSNotation(int row)
         => row <= 26
             ? new string([(char)(row + 'A' - 1)])
             : new string(['A', (char)(row + 'A' - 27)]);
@@ -20,8 +20,7 @@ public static class Utils
         return (a + b - 1) / b;
     }
     
-    [Pure]
+    public static (int Column, int Row) GetSBSCoordinate(string coordinate)
-    public static (int Column, int Row) GetSbsNotationCoordinate(string coordinate)
     {
         var column = coordinate[^1] - '0';
         if(char.IsDigit(coordinate[^2]))
@@ -34,31 +33,26 @@ public static class Utils
         return (column, row);
     }
     
-    /// <summary>
+    
-    /// Performs a SIMD-accelerated calculation that generates a buffer of bounded, scaled indices.
-    /// </summary>
-    /// <param name="scaleFactor">The amount by which to scale the sequence values.</param>
-    /// <param name="length">The total number of scalar values to generate.</param>
-    /// <param name="max">Upper limit (exclusive) for clamping values.</param>
-    /// <param name="offset">The offset to apply before clamping.</param>
     public static IBuffer<int> BoundsMatrix(float scaleFactor, int length, int max, int offset)
     {
-        var vectorSize = DivCeil(length + 1, Vector<float>.Count);
+        var vectorSize = DivCeil(length, Vector<float>.Count);
         using var buffer = MemoryAllocator.Allocate<Vector<float>>(vectorSize);
 
         var span = buffer.Span;
         var vectorMin = Vector<int>.Zero;
-        var vectorOffset = new Vector<int>(offset);
+        var vectorOffset = new Vector<int>(offset - 1);
         var vectorMax = new Vector<int>(max - 1);
         var vectorScale = new Vector<float>(scaleFactor);
 
-        var vectorSequence = Vector.CreateSequence(0f, 1f);
+        var vectorSequence = SequenceVector(0f, 1f);
 
-        var seq = -1f;
+        var seq = 0f;
         for (var i = 0; i < vectorSize; i++, seq += Vector<float>.Count)
         {
             var sequence = new Vector<float>(seq) + vectorSequence;
-            span[i] = Vector.FusedMultiplyAdd(sequence, vectorScale, vectorScale);
+            span[i] = Vector.Multiply(sequence, vectorScale);
+            span[i] = Vector.Add(span[i], vectorScale);
             span[i] = Vector.Ceiling(span[i]);
         }
         
@@ -68,9 +62,23 @@ public static class Utils
         {
             resultSpan[i] = Vector.ConvertToInt32(span[i]);
             resultSpan[i] = Vector.Add(resultSpan[i], vectorOffset);
-            resultSpan[i] = Vector.ClampNative(resultSpan[i], vectorMin, vectorMax);
+            resultSpan[i] = Vector.Min(resultSpan[i], vectorMax);
+            resultSpan[i] = Vector.Max(resultSpan[i], vectorMin);
         }
 
         return result;
     }
+
+    private static Vector<float> SequenceVector(float start, float step)
+    {
+        var vector = Vector<float>.Zero;
+        ref var reference = ref Unsafe.As<Vector<float>, float>(ref vector);
+        for (var i = 0; i < Vector<float>.Count; i++)
+        {
+            ref var current = ref Unsafe.Add(ref reference, i);
+            current = start + step * i;
+        }
+
+        return vector;
+    }
 }

Infra/Buffers/ArrayOwner.cs

@@ -7,11 +7,10 @@ public class ArrayOwner<T> : IBuffer<T> where T : unmanaged
     private readonly ArrayPool<T> _owner;
     private readonly T[] _buffer;
 
-    public ArrayOwner(ArrayPool<T> owner, int length)
+    public ArrayOwner(ArrayPool<T> owner, int size)
     {
         _owner = owner;
-        _buffer = owner.Rent(length);
+        _buffer = owner.Rent(size);
-        Length = length;
     }
     
     ~ArrayOwner() => Dispose();
@@ -24,10 +23,7 @@ public class ArrayOwner<T> : IBuffer<T> where T : unmanaged
 
     public ref T this[int index] => ref _buffer[index];
 
-    public Span<T> Span => _buffer.AsSpan(0, Length);
+    public Span<T> Span => _buffer;
-    public Memory<T> Memory => _buffer.AsMemory(0, Length);
 
     public T[] Array => _buffer;
-
-    public int Length { get; }
 }

Infra/Buffers/IBuffer.cs

@@ -5,8 +5,4 @@ public interface IBuffer<T> : IDisposable where T : unmanaged
     ref T this[int index] { get; }
         
     Span<T> Span { get; }
-        
-    Memory<T> Memory { get; }
-    
-    int Length { get; }
 }

Infra/Buffers/ImmovableMemory.cs

@@ -1,51 +0,0 @@
-using System.Buffers;
-using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
-
-namespace StitchATon2.Infra.Buffers;
-
-internal sealed unsafe class ImmovableMemory<T> : MemoryManager<T>, IBuffer<T> where T : unmanaged
-{
-    internal readonly T* Pointer;
-    private bool _disposed;
-
-    public ImmovableMemory(int length)
-    {
-        Pointer = (T*)NativeMemory.Alloc((nuint)length, (nuint)Unsafe.SizeOf<T>());
-        Length = length;
-    }
-    
-    protected override void Dispose(bool disposing)
-    {
-        if (_disposed) return;
-        NativeMemory.Free(Pointer);
-        _disposed = true;
-    }
-
-    public override Span<T> GetSpan()
-        => _disposed 
-            ? throw new ObjectDisposedException(nameof(ImmovableMemory<T>)) 
-            : new Span<T>(Pointer, Length);
-
-    public override MemoryHandle Pin(int elementIndex = 0)
-        => _disposed
-            ? throw new ObjectDisposedException(nameof(ImmovableMemory<T>))
-            : new MemoryHandle(Pointer + elementIndex);
-
-    public override void Unpin()
-    {
-    }
-
-    public ref T this[int index]
-    {
-        get
-        {
-            if (_disposed) throw new ObjectDisposedException(nameof(ImmovableMemory<T>));
-            return ref Unsafe.AsRef<T>(Pointer + index);
-        }
-    }
-
-    public Span<T> Span => GetSpan();
-    
-    public int Length { get; }
-}

Infra/Buffers/MemoryAllocator.cs

@@ -1,36 +1,15 @@
 using System.Buffers;
-using System.Runtime.CompilerServices;
 
 namespace StitchATon2.Infra.Buffers;
 
 public static class MemoryAllocator
 {
     public static IBuffer<T> Allocate<T>(int count) where T : unmanaged
-        => new ImmovableMemory<T>(count);
+        => new UnmanagedMemory<T>(count);
     
     public static IMemoryOwner<T> AllocateManaged<T>(int count)
         => MemoryPool<T>.Shared.Rent(count);
     
     public static ArrayOwner<T> AllocateArray<T>(int count) where T : unmanaged
         => new(ArrayPool<T>.Shared, count);
-
-    public static unsafe IBuffer<T> Clone<T>(this IBuffer<T> buffer) where T : unmanaged
-    {
-        if (buffer is not ImmovableMemory<T> unmanagedMemory)
-            throw new NotSupportedException();
-        
-        var newBuffer = new ImmovableMemory<T>(buffer.Length);
-        var byteCount = (uint)(Unsafe.SizeOf<T>() * buffer.Length);
-        Unsafe.CopyBlock(newBuffer.Pointer, unmanagedMemory.Pointer, byteCount);
-        return newBuffer;
-    }
-
-    public static unsafe void Copy<T>(this IBuffer<T> source, IBuffer<T> destination, int count) where T : unmanaged
-    {
-        if (source is not ImmovableMemory<T> sourceBuffer || destination is not ImmovableMemory<T> destinationBuffer)
-            throw new NotSupportedException();
-        
-        var byteCount = (uint)(Unsafe.SizeOf<T>() * count);
-        Unsafe.CopyBlock(destinationBuffer.Pointer, sourceBuffer.Pointer, byteCount);
-    }
 }

Infra/Buffers/PooledMemoryStream.cs

@@ -1,102 +0,0 @@
-using System.Buffers;
-
-namespace StitchATon2.Infra.Buffers;
-
-public class PooledMemoryStream : Stream
-{
-    private byte[] _buffer;
-    private int _length;
-    private int _position;
-    private readonly ArrayPool<byte> _pool;
-    private bool _disposed;
-
-    public PooledMemoryStream(int initialCapacity = 1024, ArrayPool<byte>? pool = null)
-    {
-        _pool = pool ?? ArrayPool<byte>.Shared;
-        _buffer = _pool.Rent(initialCapacity);
-    }
-
-    public override bool CanRead => !_disposed;
-    public override bool CanSeek => !_disposed;
-    public override bool CanWrite => !_disposed;
-    public override long Length => _length;
-    public override long Position
-    {
-        get => _position;
-        set
-        {
-            if (_disposed) throw new ObjectDisposedException(nameof(PooledMemoryStream));
-            if (value < 0 || value > int.MaxValue) throw new ArgumentOutOfRangeException();
-            _position = (int)value;
-        }
-    }
-
-    public byte[] GetBuffer() => _buffer;
-    public ArraySegment<byte> GetWrittenSegment() => new(_buffer, 0, _length);
-
-    public override void Flush() { /* no-op */ }
-
-    public override int Read(byte[] buffer, int offset, int count)
-    {
-        if (_disposed) throw new ObjectDisposedException(nameof(PooledMemoryStream));
-        int available = _length - _position;
-        int toRead = Math.Min(count, available);
-        Buffer.BlockCopy(_buffer, _position, buffer, offset, toRead);
-        _position += toRead;
-        return toRead;
-    }
-
-    public override void Write(byte[] buffer, int offset, int count)
-    {
-        if (_disposed) throw new ObjectDisposedException(nameof(PooledMemoryStream));
-        EnsureCapacity(_position + count);
-        Buffer.BlockCopy(buffer, offset, _buffer, _position, count);
-        _position += count;
-        _length = Math.Max(_length, _position);
-    }
-
-    public override long Seek(long offset, SeekOrigin origin)
-    {
-        if (_disposed) throw new ObjectDisposedException(nameof(PooledMemoryStream));
-        int newPos = origin switch
-        {
-            SeekOrigin.Begin => (int)offset,
-            SeekOrigin.Current => _position + (int)offset,
-            SeekOrigin.End => _length + (int)offset,
-            _ => throw new ArgumentOutOfRangeException()
-        };
-        if (newPos < 0) throw new IOException("Negative position");
-        _position = newPos;
-        return _position;
-    }
-
-    public override void SetLength(long value)
-    {
-        if (_disposed) throw new ObjectDisposedException(nameof(PooledMemoryStream));
-        if (value < 0 || value > int.MaxValue) throw new ArgumentOutOfRangeException();
-        EnsureCapacity((int)value);
-        _length = (int)value;
-        if (_position > _length) _position = _length;
-    }
-
-    private void EnsureCapacity(int size)
-    {
-        if (size <= _buffer.Length) return;
-        int newSize = Math.Max(size, _buffer.Length * 2);
-        byte[] newBuffer = _pool.Rent(newSize);
-        Buffer.BlockCopy(_buffer, 0, newBuffer, 0, _length);
-        _pool.Return(_buffer, clearArray: true);
-        _buffer = newBuffer;
-    }
-
-    protected override void Dispose(bool disposing)
-    {
-        if (!_disposed)
-        {
-            _pool.Return(_buffer, clearArray: true);
-            _buffer = Array.Empty<byte>();
-            _disposed = true;
-        }
-        base.Dispose(disposing);
-    }
-}

Infra/Buffers/UnmanagedMemory.cs

@@ -3,38 +3,26 @@ using System.Runtime.InteropServices;
 
 namespace StitchATon2.Infra.Buffers;
 
-/// <summary>
-/// Provide non-thread safe anti GC contiguous memory. 
-/// </summary>
-/// <typeparam name="T"></typeparam>
-[Obsolete("Use immovable memory instead")]
 internal sealed unsafe class UnmanagedMemory<T> : IBuffer<T> where T : unmanaged
 {
-    internal readonly T* Pointer;
+    private readonly void* _pointer;
-    private bool _disposed;
+    private readonly int _count;
 
-    public Memory<T> Memory => throw new NotImplementedException();
+    public ref T this[int index] => ref Unsafe.AsRef<T>((T*)_pointer + index); // *((T*)_pointer + index);
-    public int Length { get; }
 
-    public ref T this[int index] => ref Unsafe.AsRef<T>(Pointer + index);
+    public Span<T> Span => new(_pointer, _count);
 
-    public Span<T> Span => new(Pointer, Length);
+    public UnmanagedMemory(int count)
-
-    public UnmanagedMemory(int length)
     {
-        Pointer = (T*)NativeMemory.Alloc((nuint)length, (nuint)Unsafe.SizeOf<T>());
+        _pointer = NativeMemory.Alloc((nuint)count, (nuint)Unsafe.SizeOf<T>());
-        Length = length;
+        _count = count;
     }
     
     ~UnmanagedMemory() => Dispose();
 
     public void Dispose()
     {
-        if (!_disposed)
+        NativeMemory.Free(_pointer);
-        {
+        GC.SuppressFinalize(this);
-            NativeMemory.Free(Pointer);
-            GC.SuppressFinalize(this);
-            _disposed = true;
-        }
     }
 }

Infra/Encoders/Crc32.cs

@@ -15,17 +15,6 @@ public static class Crc32
         return ~crc;
     }
 
-    public static uint Compute(Stream stream, int count, uint initial = 0xFFFFFFFF)
-    {
-        uint crc = initial;
-        while (count-- > 0)
-        {
-            crc = Table[(crc ^ stream.ReadByte()) & 0xFF] ^ (crc >> 8);
-        }
-        
-        return ~crc;
-    }
-
     private static uint[] GenerateTable()
     {
         const uint poly = 0xEDB88320;

Infra/Encoders/PngPipeEncoder.cs

@@ -1,144 +0,0 @@
-using System.Buffers;
-using System.Buffers.Binary;
-using System.IO.Compression;
-using System.IO.Pipelines;
-using StitchATon2.Infra.Buffers;
-
-namespace StitchATon2.Infra.Encoders;
-
-public class PngPipeEncoder : IDisposable
-{
-    private const int BufferSize = 8 * 1024;
-    private const int FlushThreshold = 1024;
-    private const int PipeChunkThreshold = 16 * 1024;
-    
-    private readonly PipeWriter _outputPipe;
-    private readonly MemoryStream _memoryStream;
-    private readonly int _width;
-    private readonly int _height;
-
-    private readonly ZLibStream _zlibStream;
-    private bool _disposed;
-    private bool _shouldFlush;
-    
-    public PngPipeEncoder(PipeWriter outputPipe, int width, int height)
-    {
-        _outputPipe = outputPipe;
-        _width = width;
-        _height = height;
-        _memoryStream = new MemoryStream(BufferSize * 2);
-        _zlibStream = new ZLibStream(_memoryStream, CompressionLevel.Optimal, leaveOpen: true);
-        _memoryStream.SetLength(8);
-        _memoryStream.Position = 8;
-    }
-
-    ~PngPipeEncoder() => Dispose();
-
-    public void WriteHeader()
-    {
-        Span<byte> headerBytes = [
-            0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, // PNG Signature
-            0x00, 0x00, 0x00, 0x0D, // Length
-            
-            // IHDR chunk
-            0x49, 0x48, 0x44, 0x52, // IHDR
-            0x00, 0x00, 0x00, 0x00, // Reserve to write Width
-            0x00, 0x00, 0x00, 0x00, // Reserve to write Height
-            0x08, // Bit depth
-            0x02, // Color type
-            0x00, // Compression method
-            0x00, // Filter method
-            0x00, // Interlace method
-            0x00, 0x00, 0x00, 0x00, // Reserve to write CRC-32
-        ];
-        
-        BinaryPrimitives.WriteInt32BigEndian(headerBytes[16..], _width);
-        BinaryPrimitives.WriteInt32BigEndian(headerBytes[20..], _height);
-        var crc = Crc32.Compute(headerBytes.Slice(12, 17));
-        
-        BinaryPrimitives.WriteUInt32BigEndian(headerBytes[29..], crc);
-        
-        _outputPipe.Write(headerBytes);
-    }
-
-    public async Task WriteDataAsync(IBuffer<byte> buffer, bool disposeBuffer = true, CancellationToken cancellationToken = default)
-    {
-        try
-        {
-            _zlibStream.Write([0]);
-
-            var offset = 0;
-            while (buffer.Length - offset > FlushThreshold)
-            {
-                _zlibStream.Write(buffer.Span.Slice(offset, FlushThreshold));
-                await _zlibStream.FlushAsync(cancellationToken);
-                offset += FlushThreshold;
-                if (_memoryStream.Length >= BufferSize)
-                    await FlushAsync(cancellationToken);
-            }
-
-            if (buffer.Length > offset)
-            {
-                _zlibStream.Write(buffer.Span[offset..]);
-                await _zlibStream.FlushAsync(cancellationToken);
-                _shouldFlush = true;
-            }
-        }
-        finally
-        {
-            if(disposeBuffer)
-                buffer.Dispose();
-        }
-    }
-
-    private async Task FlushAsync(CancellationToken cancellationToken)
-    {
-        await _zlibStream.FlushAsync(cancellationToken);
-        var dataSize = (int)(_memoryStream.Length - 8);
-
-        _memoryStream.Write("\0\0\0\0"u8);
-
-        _memoryStream.Position = 4;
-        _memoryStream.Write("IDAT"u8);
-
-        var buffer = _memoryStream.GetBuffer();
-        BinaryPrimitives.WriteInt32BigEndian(buffer, dataSize);
-
-        // write Crc
-        var crc = Crc32.Compute(buffer.AsSpan(4, dataSize + 4));
-        BinaryPrimitives.WriteUInt32BigEndian(buffer.AsSpan(dataSize + 8), crc);
-        
-        _outputPipe.Write(buffer.AsSpan(0, dataSize + 12));
-        await _outputPipe.FlushAsync(cancellationToken);
-        
-        _memoryStream.SetLength(8);
-        _memoryStream.Position = 8;
-        _shouldFlush = false;
-    }
-
-    public async Task WriteEndOfFileAsync(CancellationToken cancellationToken = default)
-    {
-        if(_shouldFlush)
-            await FlushAsync(cancellationToken);
-        
-        Span<byte> endChunk = [
-            0x00, 0x00, 0x00, 0x00, // Length
-            0x49, 0x45, 0x4E, 0x44, // IEND
-            0xAE, 0x42, 0x60, 0x82, // Crc
-        ];
-        
-        _outputPipe.Write(endChunk);
-        Dispose();
-    }
-
-    public void Dispose()
-    {
-        if (!_disposed)
-        {
-            _zlibStream.Dispose();
-            _memoryStream.Dispose();
-            _disposed = true;
-            GC.SuppressFinalize(this);
-        }
-    }
-}

Infra/Encoders/PngStreamEncoder.cs

@@ -1,6 +1,5 @@
 using System.Buffers.Binary;
 using System.IO.Compression;
-using StitchATon2.Infra.Buffers;
 
 namespace StitchATon2.Infra.Encoders;
 
@@ -31,7 +30,7 @@ public class PngStreamEncoder : IDisposable, IAsyncDisposable
 
     ~PngStreamEncoder() => Dispose();
 
-    public async Task WriteHeader(CancellationToken cancellationToken = default)
+    public async Task WriteHeader()
     {
         byte[] headerBytes = [
             0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, // PNG Signature
@@ -55,42 +54,34 @@ public class PngStreamEncoder : IDisposable, IAsyncDisposable
         
         BinaryPrimitives.WriteUInt32BigEndian(headerBytes.AsSpan(29), crc);
         
-        await _stream.WriteAsync(headerBytes, cancellationToken);
+        await _stream.WriteAsync(headerBytes);
     }
 
-    public async Task WriteDataAsync(IBuffer<byte> buffer, bool disposeBuffer = true, CancellationToken cancellationToken = default)
+    public async Task WriteData(Memory<byte> data)
     {
-        try
+        _zlibStream.Write([0]);
+        
+        var dataSlice = data;
+        while (dataSlice.Length > FlushThreshold)
         {
-            _zlibStream.Write([0]);
+            await _zlibStream.WriteAsync(dataSlice[..FlushThreshold]);
-
+            await _zlibStream.FlushAsync();
-            var dataSlice = buffer.Memory;
+            dataSlice = dataSlice[FlushThreshold..];
-            while (dataSlice.Length > FlushThreshold)
+            if(_memoryStream.Length >= BufferSize)
-            {
+                await Flush();
-                await _zlibStream.WriteAsync(dataSlice[..FlushThreshold], cancellationToken);
-                await _zlibStream.FlushAsync(cancellationToken);
-                dataSlice = dataSlice[FlushThreshold..];
-                if (_memoryStream.Length >= BufferSize)
-                    await FlushAsync(cancellationToken);
-            }
-
-            if (dataSlice.Length > 0)
-            {
-                await _zlibStream.WriteAsync(dataSlice, cancellationToken);
-                await _zlibStream.FlushAsync(cancellationToken);
-                _shouldFlush = true;
-            }
         }
-        finally
+        
+        if (dataSlice.Length > 0)
         {
-            if(disposeBuffer)
+            await _zlibStream.WriteAsync(dataSlice);
-                buffer.Dispose();
+            await _zlibStream.FlushAsync();
+            _shouldFlush = true;
         }
     }
 
-    private async Task FlushAsync(CancellationToken cancellationToken)
+    private async Task Flush()
     {
-        await _zlibStream.FlushAsync(cancellationToken);
+        await _zlibStream.FlushAsync();
         var dataSize = (int)(_memoryStream.Length - 8);
 
         _memoryStream.Write("\0\0\0\0"u8);
@@ -105,16 +96,16 @@ public class PngStreamEncoder : IDisposable, IAsyncDisposable
         var crc = Crc32.Compute(buffer.AsSpan(4, dataSize + 4));
         BinaryPrimitives.WriteUInt32BigEndian(buffer.AsSpan(dataSize + 8), crc);
             
-        await _stream.WriteAsync(buffer.AsMemory(0, dataSize + 12), cancellationToken);
+        await _stream.WriteAsync(buffer.AsMemory(0, dataSize + 12));
         _memoryStream.SetLength(8);
         _memoryStream.Position = 8;
         _shouldFlush = false;
     }
 
-    public async ValueTask WriteEndOfFileAsync(CancellationToken cancellationToken = default)
+    public async ValueTask WriteEndOfFile()
     {
         if(_shouldFlush)
-            await FlushAsync(cancellationToken);
+            await Flush();
         
         var endChunk = new byte[] {
             0x00, 0x00, 0x00, 0x00, // Length
@@ -122,7 +113,7 @@ public class PngStreamEncoder : IDisposable, IAsyncDisposable
             0xAE, 0x42, 0x60, 0x82, // Crc
         };
         
-        await _stream.WriteAsync(endChunk, cancellationToken);
+        await _stream.WriteAsync(endChunk);
         await DisposeAsync();
     }
 

Infra/Encoders/UnsafePngEncoder.cs

@@ -1,166 +0,0 @@
-using System.Buffers;
-using System.Buffers.Binary;
-using System.IO.Compression;
-using System.IO.Pipelines;
-using StitchATon2.Infra.Buffers;
-
-namespace StitchATon2.Infra.Encoders;
-
-public class UnsafePngEncoder : IDisposable
-{
-    private const int BufferSize = 8 * 1024;
-    private const int FlushThreshold = 1024;
-    private const int PipeChunkThreshold = 16 * 1024;
-    
-    private readonly PipeWriter _outputPipe;
-    private readonly int _width;
-    private readonly int _height;
-
-    private MemoryHandle? _memoryHandle;
-    private readonly RawPointerStream _memoryStream;// = new RawPointerStream();
-    private ZLibStream? _zlibStream;// = new ZLibStream(_memoryStream, CompressionLevel.Optimal, leaveOpen: true);
-    private bool _disposed;
-    private bool _shouldFlush;
-    
-    public UnsafePngEncoder(PipeWriter outputPipe, int width, int height)
-    {
-        _outputPipe = outputPipe;
-        _width = width;
-        _height = height;
-
-        _memoryStream = new RawPointerStream();
-    }
-
-    ~UnsafePngEncoder() => Dispose();
-
-    public void WriteHeader()
-    {
-        Span<byte> headerBytes = [
-            0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, // PNG Signature
-            0x00, 0x00, 0x00, 0x0D, // Length
-            
-            // IHDR chunk
-            0x49, 0x48, 0x44, 0x52, // IHDR
-            0x00, 0x00, 0x00, 0x00, // Reserve to write Width
-            0x00, 0x00, 0x00, 0x00, // Reserve to write Height
-            0x08, // Bit depth
-            0x02, // Color type
-            0x00, // Compression method
-            0x00, // Filter method
-            0x00, // Interlace method
-            0x00, 0x00, 0x00, 0x00, // Reserve to write CRC-32
-        ];
-        
-        BinaryPrimitives.WriteInt32BigEndian(headerBytes[16..], _width);
-        BinaryPrimitives.WriteInt32BigEndian(headerBytes[20..], _height);
-        var crc = Crc32.Compute(headerBytes.Slice(12, 17));
-        
-        BinaryPrimitives.WriteUInt32BigEndian(headerBytes[29..], crc);
-        
-        _outputPipe.Write(headerBytes);
-    }
-
-    private unsafe void Initialize()
-    {
-        if (_memoryHandle == null)
-        {
-            var memory = _outputPipe.GetMemory(PipeChunkThreshold);
-            var handle = memory.Pin();
-            _memoryStream.Initialize((byte*)handle.Pointer, 0, memory.Length);
-            _memoryHandle = handle;
-            
-            _memoryStream.SetLength(8);
-            _memoryStream.Position = 8;
-            _zlibStream = new ZLibStream(_memoryStream, CompressionLevel.Optimal, true);
-        }
-    }
-
-    public async Task WriteDataAsync(IBuffer<byte> buffer, bool disposeBuffer = true, CancellationToken cancellationToken = default)
-    {
-        Initialize();
-        _zlibStream!.Write([0]);
-        
-        var offset = 0;
-        while (buffer.Length - offset > FlushThreshold)
-        {
-            _zlibStream.Write(buffer.Span.Slice(offset, FlushThreshold));
-            await _zlibStream.FlushAsync(cancellationToken);
-            offset += FlushThreshold;
-            if(_memoryStream.Length >= BufferSize)
-                await FlushAsync(cancellationToken);
-        }
-        
-        if (buffer.Length > offset)
-        {
-            _zlibStream.Write(buffer.Span[offset..]);
-            await _zlibStream.FlushAsync(cancellationToken);
-            _shouldFlush = true;
-        }
-        
-        if(disposeBuffer) buffer.Dispose();
-    }
-
-    private async Task FlushAsync(CancellationToken cancellationToken)
-    {
-        await _zlibStream!.FlushAsync(cancellationToken);
-        var dataSize = (int)(_memoryStream.Length - 8);
-        
-        _memoryStream.Position = 0;
-        Span<byte> buffer = stackalloc byte[4];
-        BinaryPrimitives.WriteInt32BigEndian(buffer, dataSize);
-        _memoryStream.Write(buffer);
-        _memoryStream.Write("IDAT"u8);
-
-        _memoryStream.Position = 4;
-
-        // write Crc
-        var crc = Crc32.Compute(_memoryStream, dataSize + 4);
-        BinaryPrimitives.WriteUInt32BigEndian(buffer, crc);
-        _memoryStream.Write(buffer);
-
-        _outputPipe.Advance((int)_memoryStream.Length);
-        
-        await _memoryStream.DisposeAsync();
-        _memoryHandle!.Value.Dispose();
-        _memoryHandle = null;
-        
-        _shouldFlush = false;
-    }
-
-    public async Task WriteEndOfFileAsync(CancellationToken cancellationToken = default)
-    {
-        if(_shouldFlush)
-            await FlushAsync(cancellationToken);
-        
-        Span<byte> endChunk = [
-            0x00, 0x00, 0x00, 0x00, // Length
-            0x49, 0x45, 0x4E, 0x44, // IEND
-            0xAE, 0x42, 0x60, 0x82, // Crc
-        ];
-        
-        _outputPipe.Write(endChunk);
-        Dispose();
-    }
-
-    public void Dispose()
-    {
-        if (!_disposed)
-        {
-            if (_memoryHandle != null)
-            {
-                _zlibStream!.Dispose();
-                _memoryStream.Dispose();
-            }
-            _disposed = true;
-            GC.SuppressFinalize(this);
-        }
-    }
-
-    private unsafe class RawPointerStream : UnmanagedMemoryStream
-    {
-        public void Initialize(byte* pointer, int length, int capacity)
-        {
-            Initialize(pointer, length, capacity, FileAccess.ReadWrite);
-        }
-    }
-}

Infra/ImageIntegral.cs

@@ -1,3 +1,4 @@
+using System.Buffers;
 using System.IO.MemoryMappedFiles;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
@@ -5,7 +6,6 @@ using SixLabors.ImageSharp.Formats;
 using SixLabors.ImageSharp.Formats.Png;
 using SixLabors.ImageSharp.PixelFormats;
 using StitchATon2.Infra.Buffers;
-using StitchATon2.Infra.Synchronization;
 
 namespace StitchATon2.Infra;
 
@@ -18,9 +18,9 @@ public class ImageIntegral : IDisposable
     private readonly int _width;
     private readonly int _height;
 
-    private ManualResetEventSlim[]? _rowLocks;
+    private IMemoryOwner<ManualResetEventSlim>? _rowLocks;
     private MemoryMappedFile? _memoryMappedFile;
-    private readonly Lock _lock = new();
+    private readonly object _lock = new();
 
     private readonly ManualResetEventSlim _queueLock = new(true);
     private readonly ManualResetEventSlim _initializationLock = new(false);
@@ -58,14 +58,14 @@ public class ImageIntegral : IDisposable
             {
                 if (_memoryMappedFile is null)
                 {
-                    Task.Run(() => Initialize(cancellationToken), cancellationToken);
+                    Task.Factory.StartNew(() => Initialize(cancellationToken), cancellationToken);
                     _initializationLock.Wait(cancellationToken);
                     _initializationLock.Dispose();
                 }
             }
         }
 
-        _rowLocks?[row].Wait(cancellationToken);
+        _rowLocks?.Memory.Span[row].Wait(cancellationToken);
     }
 
     private void Initialize(CancellationToken cancellationToken)
@@ -86,8 +86,8 @@ public class ImageIntegral : IDisposable
         }
         
         var taskQueue = backedFileStream == null
-            ? TaskHelper.SynchronizedTaskFactory.StartNew(() => { }, cancellationToken)
+            ? Task.CompletedTask
-            : AllocateBackedFile(backedFileStream, header, cancellationToken);
+            : AllocateBackedFile(backedFileStream, header);
 
         taskQueue = taskQueue.ContinueWith(
             _ =>
@@ -100,11 +100,12 @@ public class ImageIntegral : IDisposable
         // initialize resource gating, all rows is expected to be locked
         // if the backed file require to allocate, it should be safe to do this
         // asynchronously
-        var rowLocks = new ManualResetEventSlim[_height];
+        var rowLocks = MemoryAllocator.AllocateManaged<ManualResetEventSlim>(_height);
+        var rowLocksSpan = rowLocks.Memory.Span;
         for (int i = 0; i < _height; i++)
         {
             var isOpen = i < header.ProcessedRows;
-            rowLocks[i] = new ManualResetEventSlim(isOpen);
+            rowLocksSpan[i] = new ManualResetEventSlim(isOpen);
         }
 
         _rowLocks = rowLocks;
@@ -128,7 +129,7 @@ public class ImageIntegral : IDisposable
         var imageBuffer = image.Frames.RootFrame.PixelBuffer;
         
         var accumulator = Int32Pixel.Zero;
-        var buffer = MemoryAllocator.Allocate<Int32Pixel>(_width);
+        var buffer = MemoryAllocator.AllocateArray<Int32Pixel>(_width);
         var processedRows = _processedRows;
         Interlocked.Exchange(ref _queueCounter, 0);
         
@@ -142,55 +143,50 @@ public class ImageIntegral : IDisposable
                 buffer[x] = accumulator;
             }
             
-            taskQueue = QueueWriterTask(taskQueue, 0, buffer.Clone(), cancellationToken);
+            taskQueue = QueueWriterTask(taskQueue, 0, buffer.Clone(_width), cancellationToken);
             processedRows++;
         }
         else
         {
-            ReadRow(processedRows - 1, buffer.Span);
+            ReadRow(processedRows - 1, buffer);
         }
         
         if(cancellationToken.IsCancellationRequested)
             return;
 
         var prevBuffer = buffer;
-        buffer = MemoryAllocator.Allocate<Int32Pixel>(_width);
+        buffer = MemoryAllocator.AllocateArray<Int32Pixel>(_width);
-        try
+        
+        for (int y = processedRows; y < image.Height; y++)
         {
-            for (int y = processedRows; y < image.Height; y++)
+            var sourceRow = imageBuffer.DangerousGetRowSpan(y);
+            accumulator = (Int32Pixel)sourceRow[0];
+            buffer[0] = accumulator + prevBuffer[0];
+
+            // Process all other columns
+            for (var x = 1; x < sourceRow.Length; x++)
             {
-                var sourceRow = imageBuffer.DangerousGetRowSpan(y);
+                accumulator.Accumulate(sourceRow[x]);
-                accumulator = (Int32Pixel)sourceRow[0];
+                buffer[x] = accumulator + prevBuffer[x];
-                buffer[0] = accumulator + prevBuffer[0];
-
-                // Process all other columns
-                for (var x = 1; x < sourceRow.Length; x++)
-                {
-                    accumulator.Accumulate(sourceRow[x]);
-                    buffer[x] = accumulator + prevBuffer[x];
-                }
-
-                if (_queueCounter >= MaxProcessingQueue)
-                {
-                    _queueLock.Reset();
-                    _queueLock.Wait(cancellationToken);
-                }
-
-                if(cancellationToken.IsCancellationRequested)
-                    break;
-
-                var writeBuffer = prevBuffer;
-                buffer.Copy(writeBuffer, _width);
-                taskQueue = QueueWriterTask(taskQueue, y, writeBuffer, cancellationToken);
-                prevBuffer = buffer;
-                buffer = MemoryAllocator.Allocate<Int32Pixel>(_width);
             }
-        }
+
-        finally
+            if (_queueCounter >= MaxProcessingQueue)
-        {
+            {
-            buffer.Dispose();
+                _queueLock.Reset();
+                _queueLock.Wait(cancellationToken);
+            }
+
+            if(cancellationToken.IsCancellationRequested)
+                break;
+
+            var writeBuffer = prevBuffer;
+            Array.Copy(buffer.Array, writeBuffer.Array, image.Width);
+            taskQueue = QueueWriterTask(taskQueue, y, writeBuffer, cancellationToken);
+            prevBuffer = buffer;
+            buffer = MemoryAllocator.AllocateArray<Int32Pixel>(_width);
         }
 
+        buffer.Dispose();
         if(cancellationToken.IsCancellationRequested)
             return;
 
@@ -209,7 +205,7 @@ public class ImageIntegral : IDisposable
     private Task QueueWriterTask(
         Task taskQueue,
         int row,
-        IBuffer<Int32Pixel> writeBuffer,
+        ArrayOwner<Int32Pixel> writeBuffer,
         CancellationToken cancellationToken)
     {
         Interlocked.Increment(ref _queueCounter);
@@ -217,10 +213,10 @@ public class ImageIntegral : IDisposable
         return taskQueue.ContinueWith(_ =>
         {
             using (var view = AcquireView(row, MemoryMappedFileAccess.Write))
-                view.DangerousWriteSpan(0, writeBuffer.Span, 0, _width);
+                view.WriteArray(0, writeBuffer.Array, 0, _width);
                 
             writeBuffer.Dispose();
-            _rowLocks![row].Set();
+            _rowLocks!.Memory.Span[row].Set();
             Interlocked.Increment(ref _processedRows);
 
             using (var view = AcquireHeaderView(MemoryMappedFileAccess.Write))
@@ -253,6 +249,12 @@ public class ImageIntegral : IDisposable
         view.DangerousReadSpan(0, buffer, 0, _width);
     }
 
+    private void ReadRow(int row, IBuffer<Int32Pixel> buffer)
+    {
+        using var view = AcquireView(row, MemoryMappedFileAccess.Read);
+        view.DangerousReadSpan(0, buffer.Span, 0, _width);
+    }
+
     private FileStream? InitializeBackedFile(string path, out Header header)
     {
         var expectedHeader = Header.CreateInitial(_width, _height);
@@ -309,35 +311,33 @@ public class ImageIntegral : IDisposable
         return fs;
     }
 
-    private static Task AllocateBackedFile(FileStream fileStream, Header header, CancellationToken cancellationToken)
+    private static async Task AllocateBackedFile(FileStream fileStream, Header header)
     {
-        return TaskHelper.SynchronizedTaskFactory.StartNew(() =>
+        // The input filestream is expected to be empty with
-        {
+        // initial cursor at the beginning of the file and the content
-            // The input filestream is expected to be empty with
+        // is pre-allocated for at least Header.Length bytes
-            // initial cursor at the beginning of the file and the content
+        // No other process should be accessed the file while being
-            // is pre-allocated for at least Header.Length bytes
+        // allocated.
-            // No other process should be accessed the file while being
+        // Allocated bytes is not necessary to be zeroed.
-            // allocated.
-            // Allocated bytes is not necessary to be zeroed.
 
-            // const int writeBufferSize = 4 * 1024;
+        // const int writeBufferSize = 4 * 1024;
-            // using var writeBuffer = MemoryPool<byte>.Shared.Rent(writeBufferSize);
+        // using var writeBuffer = MemoryPool<byte>.Shared.Rent(writeBufferSize);
-            //
+        //
-            // var written = 0;
+        // var written = 0;
-            // while (written + writeBufferSize < header.Length)
+        // while (written + writeBufferSize < header.Length)
-            // {
+        // {
-            //     await fileStream.WriteAsync(writeBuffer.Memory, cancellationToken);
+        //     await fileStream.WriteAsync(writeBuffer.Memory, cancellationToken);
-            //     written += writeBufferSize;
+        //     written += writeBufferSize;
-            // }
+        // }
-            //
+        //
-            // if (written < header.Length)
+        // if (written < header.Length)
-            // {
+        // {
-            //     await fileStream.WriteAsync(writeBuffer.Memory[..(header.Length - written)], cancellationToken);
+        //     await fileStream.WriteAsync(writeBuffer.Memory[..(header.Length - written)], cancellationToken);
-            // }
+        // }
         
-            fileStream.SetLength(header.Length + Header.Size);
+        fileStream.SetLength(header.Length + Header.Size);
-            fileStream.Dispose();
+        
-        }, cancellationToken);
+        await fileStream.DisposeAsync();
     }
 
     [StructLayout(LayoutKind.Sequential)]
@@ -368,8 +368,11 @@ public class ImageIntegral : IDisposable
         if (_rowLocks is { } locks)
         {
             _rowLocks = null;
+            var lockSpan = locks.Memory.Span;
             for(int i = 0; i < _height; i++)
-                locks[i].Dispose();
+                lockSpan[i].Dispose();
+
+            locks.Dispose();
         }
     }
 

Infra/Int32Pixel.cs

@@ -68,12 +68,6 @@ public record struct Int32Pixel
         return new Int32Pixel(a.R / b, a.G / b, a.B / b);
     }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static Int32Pixel operator /(Int32Pixel a, float b)
-    {
-        return new Int32Pixel((byte)(a.R / b), (byte)(a.G / b), (byte)(a.B / b));
-    }
-
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static explicit operator Int32Pixel(Rgb24 pixel)
     {

Infra/StitchATon2.Infra.csproj

@@ -1,14 +1,14 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net9.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="SixLabors.ImageSharp" Version="3.1.11" />
+      <PackageReference Include="SixLabors.ImageSharp" Version="3.1.10" />
     </ItemGroup>
 
 </Project>

Infra/Synchronization/TaskHelper.cs

@@ -2,7 +2,11 @@ namespace StitchATon2.Infra.Synchronization;
 
 public static class TaskHelper
 {
-    public static readonly TaskFactory SynchronizedTaskFactory = new(
+    public static TaskFactory CreateTaskFactory()
-        TaskCreationOptions.LongRunning,
+    {
-        TaskContinuationOptions.ExecuteSynchronously);
+        return new TaskFactory(
+            TaskCreationOptions.AttachedToParent,
+            TaskContinuationOptions.ExecuteSynchronously
+            );
+    }
 }

Infra/Utils.cs

@@ -1,16 +1,25 @@
 using System.IO.MemoryMappedFiles;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using StitchATon2.Infra.Buffers;
 
 namespace StitchATon2.Infra;
 
-internal static class Utils
+public static class Utils
 {
+    [UnsafeAccessor(UnsafeAccessorKind.Field, Name = "_buffer")]
+    private static extern ref SafeBuffer GetSafeBuffer(this UnmanagedMemoryAccessor view);
+
+    [UnsafeAccessor(UnsafeAccessorKind.Field, Name = "_offset")]
+    private static extern ref long GetOffset(this UnmanagedMemoryAccessor view);
+
     private static unsafe uint AlignedSizeOf<T>() where T : unmanaged
     {
         uint size = (uint)sizeof(T);
-        return size is 1 or 2 ? size : (uint)((size + 3) & ~3);
+        return size is 1 or 2 ? size : (uint)((size + 3) & (~3));
     }
 
-    internal static void DangerousReadSpan<T>(this MemoryMappedViewAccessor view, long position, Span<T> span, int offset, int count)
+    public static void DangerousReadSpan<T>(this UnmanagedMemoryAccessor view, long position, Span<T> span, int offset, int count)
         where T : unmanaged
     {
         uint sizeOfT = AlignedSizeOf<T>();
@@ -29,14 +38,19 @@ internal static class Utils
             }
         }
 
-        var byteOffset = (ulong)(view.PointerOffset + position);
+        var byteOffset = (ulong)(view.GetOffset() + position);
-        view.SafeMemoryMappedViewHandle.ReadSpan(byteOffset, span.Slice(offset, n));
+        view.GetSafeBuffer().ReadSpan(byteOffset, span.Slice(offset, n));
     }
 
-    internal static void DangerousWriteSpan<T>(this MemoryMappedViewAccessor view, long position, Span<T> span, int offset, int count)
+    public static ArrayOwner<T> Clone<T>(this ArrayOwner<T> arrayOwner, int length) where T : unmanaged
-        where T : unmanaged
     {
-        var byteOffset = (ulong)(view.PointerOffset + position);
+        var newArrayOwner = MemoryAllocator.AllocateArray<T>(length);
-        view.SafeMemoryMappedViewHandle.WriteSpan<T>(byteOffset, span.Slice(offset, count));
+        Array.Copy(arrayOwner.Array, 0, newArrayOwner.Array, 0, length);
+        return newArrayOwner;
+    }
+
+    public static void CopyTo<T>(this ArrayOwner<T> arrayOwner, ArrayOwner<T> target, int length) where T : unmanaged
+    {
+        Array.Copy(arrayOwner.Array, 0, target.Array, 0, length);
     }
 }

README.md

@@ -1,42 +0,0 @@
-# Stitch-a-ton Contest Submission
-
-Repository moved to: https://github.com/denniskematian/GigATon
-
-## Installation
-
-This project is build using .NET 9, with SixLabors.ImageSharp as the only external library.
-Please refer to [install dotnet SDK on Debian](https://learn.microsoft.com/en-us/dotnet/core/install/linux-debian?tabs=dotnet9)
-for details.
-
-### 1. Build
-
-Install dependencies:
-```
-wget https://packages.microsoft.com/config/debian/12/packages-microsoft-prod.deb
-sudo dpkg -i packages-microsoft-prod.deb
-sudo apt update
-sudo apt install -y dotnet-sdk-9.0
-```
-
-Build the project in `App` folder using command:
-```
-dotnet publish -c Release -r linux-arm64 --self-contained true -o ./publish
-```
-
-### 2. Running the app
-
-After publishing, enter the folder `/publish` then run
-```
-./StitchATon2.App
-```
-
-## Ideas
-
-Since we only serve a static assets and the output is downscale only, I think it's good to pre-process each image to [image integral](https://en.wikipedia.org/wiki/Summed-area_table) first and then save it to another directory (eg. temp).
-
-Later, we can apply Box Filter averaging on the fly to output Stream (HttpResponse).
-
-## Approach
-
-This project is heavily depends on Memory Mapped File to reduce processing overhead and memory pressure to allow HTTP serve more request.
-The MMF is used to store the Image Integral of provided asset.

StitchATon2.Benchmark/SingleTileBenchmark.cs

@@ -1,77 +0,0 @@
-using System.Net.Http.Json;
-using BenchmarkDotNet.Attributes;
-using StitchATon2.Domain;
-
-namespace StitchATon2.Benchmark;
-
-public class SingleTileBenchmark
-{
-    private const string Url = "http://localhost:5088/api/image/generate";
-    private readonly TileManager _tileManager = new(Configuration.Default);
-    private readonly Random _random = new();
-    private readonly HttpClient _client = new();
-
-    private string GetRandomCoordinatePair()
-    {
-        var maxId = _tileManager.Configuration.Rows
-                    * _tileManager.Configuration.Columns;
-        
-        var id = _random.Next(maxId);
-        var tile = _tileManager.GetTile(id);
-        return $"{tile.Coordinate}:{tile.Coordinate}";
-    }
-
-    private JsonContent GetRandomDto(float scale, float offsetX = 0, float offsetY = 0)
-    {
-        return JsonContent.Create(new
-        {
-            canvas_rect = GetRandomCoordinatePair(),
-            crop_offset = (float[]) [offsetX, offsetY],
-            crop_size = (float[]) [1f - offsetX, 1f -  offsetY],
-            output_scale = scale,
-        });
-    }
-
-    private JsonContent GetRandomDtoWithOffset(float scale)
-    {
-        var offsetX = _random.NextSingle();
-        var offsetY = _random.NextSingle();
-        return GetRandomDto(scale, offsetX, offsetY);
-    }
-
-    [Benchmark]
-    public async Task NoScaling()
-    {
-        await _client.PostAsync(Url, GetRandomDto(1f));
-    }
-    
-    [Benchmark]
-    public async Task ScaleHalf()
-    {        
-        await _client.PostAsync(Url, GetRandomDto(.5f));
-    }
-    
-    [Benchmark]
-    public async Task ScaleQuarter()
-    {
-        await _client.PostAsync(Url, GetRandomDto(.25f));
-    }
-
-    [Benchmark]
-    public async Task NoScalingWithOffset()
-    {
-        await _client.PostAsync(Url, GetRandomDtoWithOffset(1f));
-    }
-    
-    [Benchmark]
-    public async Task ScaleHalfWithOffset()
-    {        
-        await _client.PostAsync(Url, GetRandomDtoWithOffset(.5f));
-    }
-    
-    [Benchmark]
-    public async Task ScaleQuarterWithOffset()
-    {
-        await _client.PostAsync(Url, GetRandomDtoWithOffset(.25f));
-    }
-}

StitchATon2.sln

@@ -6,10 +6,6 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "StitchATon2.Domain", "Domai
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "StitchATon2.Infra", "Infra\StitchATon2.Infra.csproj", "{E602F3FC-6139-4B30-AC5A-75815E6340A4}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "StitchATon2.Benchmark", "StitchATon2.Benchmark\StitchATon2.Benchmark.csproj", "{2F9B169C-C799-4489-B864-F912D69C5D3E}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ConsoleApp", "ConsoleApp\ConsoleApp.csproj", "{D5B2A2E9-974A-43DD-A5D1-E7226CD03AFF}"
-EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -28,13 +24,5 @@ Global
 		{E602F3FC-6139-4B30-AC5A-75815E6340A4}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{E602F3FC-6139-4B30-AC5A-75815E6340A4}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{E602F3FC-6139-4B30-AC5A-75815E6340A4}.Release|Any CPU.Build.0 = Release|Any CPU
-		{2F9B169C-C799-4489-B864-F912D69C5D3E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{2F9B169C-C799-4489-B864-F912D69C5D3E}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{2F9B169C-C799-4489-B864-F912D69C5D3E}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{2F9B169C-C799-4489-B864-F912D69C5D3E}.Release|Any CPU.Build.0 = Release|Any CPU
-		{D5B2A2E9-974A-43DD-A5D1-E7226CD03AFF}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{D5B2A2E9-974A-43DD-A5D1-E7226CD03AFF}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{D5B2A2E9-974A-43DD-A5D1-E7226CD03AFF}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{D5B2A2E9-974A-43DD-A5D1-E7226CD03AFF}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal

global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "9.0.0",
+    "version": "8.0.0",
     "rollForward": "latestMinor",
     "allowPrerelease": false
   }