cancellation support for encoders

src/ImageSharp/Advanced/AdvancedImageExtensions.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Formats;
 using SixLabors.ImageSharp.Memory;
@@ -73,9 +74,10 @@ namespace SixLabors.ImageSharp.Advanced
         /// </summary>
         /// <param name="source">The source image.</param>
         /// <param name="visitor">The image visitor.</param>
+        /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
         /// <returns>A  <see cref="Task"/> representing the asynchronous operation.</returns>
-        public static Task AcceptVisitorAsync(this Image source, IImageVisitorAsync visitor)
+        public static Task AcceptVisitorAsync(this Image source, IImageVisitorAsync visitor, CancellationToken cancellationToken)
-            => source.AcceptAsync(visitor);
+            => source.AcceptAsync(visitor, cancellationToken);
 
         /// <summary>
         /// Gets the configuration for the image.

src/ImageSharp/Advanced/IImageVisitor.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Apache License, Version 2.0.
 
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -31,9 +32,10 @@ namespace SixLabors.ImageSharp.Advanced
         /// Provides a pixel-specific implementation for a given operation.
         /// </summary>
         /// <param name="image">The image.</param>
+        /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
         /// <typeparam name="TPixel">The pixel type.</typeparam>
         /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
-        Task VisitAsync<TPixel>(Image<TPixel> image)
+        Task VisitAsync<TPixel>(Image<TPixel> image, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>;
     }
 }

src/ImageSharp/Formats/Bmp/BmpEncoder.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.PixelFormats;
@@ -42,11 +43,11 @@ namespace SixLabors.ImageSharp.Formats.Bmp
         }
 
         /// <inheritdoc/>
-        public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             var encoder = new BmpEncoderCore(this, image.GetMemoryAllocator());
-            return encoder.EncodeAsync(image, stream);
+            return encoder.EncodeAsync(image, stream, cancellationToken);
         }
     }
 }

src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs

@@ -5,6 +5,7 @@ using System;
 using System.Buffers;
 using System.IO;
 using System.Runtime.InteropServices;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Common.Helpers;
@@ -19,7 +20,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp
     /// <summary>
     /// Image encoder for writing an image to a stream as a Windows bitmap.
     /// </summary>
-    internal sealed class BmpEncoderCore
+    internal sealed class BmpEncoderCore : IImageEncoderInternals
     {
         /// <summary>
         /// The amount to pad each row by.
@@ -97,32 +98,9 @@ namespace SixLabors.ImageSharp.Formats.Bmp
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="image">The <see cref="ImageFrame{TPixel}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
-        public async Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        /// <param name="cancellationToken">The token to request cancellation.</param>
+        public void Encode<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>
-        {
-            if (stream.CanSeek)
-            {
-                this.Encode(image, stream);
-            }
-            else
-            {
-                using (var ms = new MemoryStream())
-                {
-                    this.Encode(image, ms);
-                    ms.Position = 0;
-                    await ms.CopyToAsync(stream).ConfigureAwait(false);
-                }
-            }
-        }
-
-        /// <summary>
-        /// Encodes the image to the specified stream from the <see cref="ImageFrame{TPixel}"/>.
-        /// </summary>
-        /// <typeparam name="TPixel">The pixel format.</typeparam>
-        /// <param name="image">The <see cref="ImageFrame{TPixel}"/> to encode from.</param>
-        /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
-        public void Encode<TPixel>(Image<TPixel> image, Stream stream)
-        where TPixel : unmanaged, IPixel<TPixel>
         {
             Guard.NotNull(image, nameof(image));
             Guard.NotNull(stream, nameof(stream));

src/ImageSharp/Formats/Gif/GifEncoder.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.PixelFormats;
@@ -41,11 +42,11 @@ namespace SixLabors.ImageSharp.Formats.Gif
         }
 
         /// <inheritdoc/>
-        public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             var encoder = new GifEncoderCore(image.GetConfiguration(), this);
-            return encoder.EncodeAsync(image, stream);
+            return encoder.EncodeAsync(image, stream, cancellationToken);
         }
     }
 }

src/ImageSharp/Formats/Gif/GifEncoderCore.cs

@@ -6,6 +6,7 @@ using System.Buffers;
 using System.IO;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Memory;
@@ -18,7 +19,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
     /// <summary>
     /// Implements the GIF encoding protocol.
     /// </summary>
-    internal sealed class GifEncoderCore
+    internal sealed class GifEncoderCore : IImageEncoderInternals
     {
         /// <summary>
         /// Used for allocating memory during processing operations.
@@ -75,25 +76,9 @@ namespace SixLabors.ImageSharp.Formats.Gif
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="image">The <see cref="Image{TPixel}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
-        public async Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        /// <param name="cancellationToken">The token to request cancellation.</param>
+        public void Encode<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>
-        {
-            using (var ms = new MemoryStream())
-            {
-                this.Encode(image, ms);
-                ms.Position = 0;
-                await ms.CopyToAsync(stream).ConfigureAwait(false);
-            }
-        }
-
-        /// <summary>
-        /// Encodes the image to the specified stream from the <see cref="Image{TPixel}"/>.
-        /// </summary>
-        /// <typeparam name="TPixel">The pixel format.</typeparam>
-        /// <param name="image">The <see cref="Image{TPixel}"/> to encode from.</param>
-        /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
-        public void Encode<TPixel>(Image<TPixel> image, Stream stream)
-        where TPixel : unmanaged, IPixel<TPixel>
         {
             Guard.NotNull(image, nameof(image));
             Guard.NotNull(stream, nameof(stream));

src/ImageSharp/Formats/IImageEncoder.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -27,8 +28,9 @@ namespace SixLabors.ImageSharp.Formats
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="image">The <see cref="Image{TPixel}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
+        /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
         /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
-        Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>;
     }
 }

src/ImageSharp/Formats/IImageEncoderInternals.cs

@@ -0,0 +1,25 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using System.IO;
+using System.Threading;
+using SixLabors.ImageSharp.PixelFormats;
+
+namespace SixLabors.ImageSharp.Formats
+{
+    /// <summary>
+    /// Abstraction for shared internals for ***DecoderCore implementations to be used with <see cref="ImageEncoderUtilities"/>.
+    /// </summary>
+    internal interface IImageEncoderInternals
+    {
+        /// <summary>
+        /// Encodes the image.
+        /// </summary>
+        /// <param name="image">The image.</param>
+        /// <param name="stream">The stream.</param>
+        /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
+        /// <typeparam name="TPixel">The pixel type.</typeparam>
+        void Encode<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
+            where TPixel : unmanaged, IPixel<TPixel>;
+    }
+}

src/ImageSharp/Formats/ImageEncoderUtilities.cs

@@ -0,0 +1,43 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SixLabors.ImageSharp.Advanced;
+using SixLabors.ImageSharp.PixelFormats;
+
+namespace SixLabors.ImageSharp.Formats
+{
+    internal static class ImageEncoderUtilities
+    {
+        public static async Task EncodeAsync<TPixel>(
+            this IImageEncoderInternals encoder,
+            Image<TPixel> image,
+            Stream stream,
+            CancellationToken cancellationToken)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            Configuration configuration = image.GetConfiguration();
+            if (stream.CanSeek)
+            {
+                encoder.Encode(image, stream, cancellationToken);
+            }
+            else
+            {
+                using var ms = new MemoryStream();
+                encoder.Encode(image, ms, cancellationToken);
+                ms.Position = 0;
+                await ms.CopyToAsync(stream, configuration.StreamProcessingBufferSize, cancellationToken)
+                    .ConfigureAwait(false);
+            }
+        }
+
+        public static void Encode<TPixel>(
+            this IImageEncoderInternals encoder,
+            Image<TPixel> image,
+            Stream stream)
+            where TPixel : unmanaged, IPixel<TPixel>
+            => encoder.Encode(image, stream, default);
+    }
+}

src/ImageSharp/Formats/Jpeg/JpegEncoder.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -43,26 +44,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="image">The <see cref="Image{TPixel}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
+        /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
         /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
-        public async Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             var encoder = new JpegEncoderCore(this);
-
+            return encoder.EncodeAsync(image, stream, cancellationToken);
-            if (stream.CanSeek)
-            {
-                encoder.Encode(image, stream);
-            }
-            else
-            {
-                // this hack has to be be here because JpegEncoderCore is unsafe
-                using (var ms = new MemoryStream())
-                {
-                    encoder.Encode(image, ms);
-                    ms.Position = 0;
-                    await ms.CopyToAsync(stream).ConfigureAwait(false);
-                }
-            }
         }
     }
 }

src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs

@@ -6,6 +6,7 @@ using System.Buffers.Binary;
 using System.IO;
 using System.Linq;
 using System.Runtime.CompilerServices;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Common.Helpers;
 using SixLabors.ImageSharp.Formats.Jpeg.Components;
@@ -23,7 +24,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
     /// <summary>
     /// Image encoder for writing an image to a stream as a jpeg.
     /// </summary>
-    internal sealed unsafe class JpegEncoderCore
+    internal sealed unsafe class JpegEncoderCore : IImageEncoderInternals
     {
         /// <summary>
         /// The number of quantization tables.
@@ -194,8 +195,9 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="image">The image to write from.</param>
         /// <param name="stream">The stream to write to.</param>
-        public void Encode<TPixel>(Image<TPixel> image, Stream stream)
+        /// <param name="cancellationToken">The token to request cancellation.</param>
-        where TPixel : unmanaged, IPixel<TPixel>
+        public void Encode<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
+            where TPixel : unmanaged, IPixel<TPixel>
         {
             Guard.NotNull(image, nameof(image));
             Guard.NotNull(stream, nameof(stream));

src/ImageSharp/Formats/Png/PngEncoder.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.PixelFormats;
@@ -71,13 +72,14 @@ namespace SixLabors.ImageSharp.Formats.Png
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="image">The <see cref="Image{TPixel}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
+        /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
         /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
-        public async Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        public async Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             using (var encoder = new PngEncoderCore(image.GetMemoryAllocator(), image.GetConfiguration(), new PngEncoderOptions(this)))
             {
-                await encoder.EncodeAsync(image, stream).ConfigureAwait(false);
+                await encoder.EncodeAsync(image, stream, cancellationToken).ConfigureAwait(false);
             }
         }
     }

src/ImageSharp/Formats/Png/PngEncoderCore.cs

@@ -7,6 +7,7 @@ using System.Buffers.Binary;
 using System.IO;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Formats.Png.Chunks;
@@ -21,7 +22,7 @@ namespace SixLabors.ImageSharp.Formats.Png
     /// <summary>
     /// Performs the png encoding operation.
     /// </summary>
-    internal sealed class PngEncoderCore : IDisposable
+    internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
     {
         /// <summary>
         /// The maximum block size, defaults at 64k for uncompressed blocks.
@@ -127,31 +128,8 @@ namespace SixLabors.ImageSharp.Formats.Png
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="image">The <see cref="ImageFrame{TPixel}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
-        public async Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        /// <param name="cancellationToken">The token to request cancellation.</param>
-            where TPixel : unmanaged, IPixel<TPixel>
+        public void Encode<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
-        {
-            if (stream.CanSeek)
-            {
-                this.Encode(image, stream);
-            }
-            else
-            {
-                using (var ms = new MemoryStream())
-                {
-                    this.Encode(image, ms);
-                    ms.Position = 0;
-                    await ms.CopyToAsync(stream).ConfigureAwait(false);
-                }
-            }
-        }
-
-        /// <summary>
-        /// Encodes the image to the specified stream from the <see cref="Image{TPixel}"/>.
-        /// </summary>
-        /// <typeparam name="TPixel">The pixel format.</typeparam>
-        /// <param name="image">The <see cref="ImageFrame{TPixel}"/> to encode from.</param>
-        /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
-        public void Encode<TPixel>(Image<TPixel> image, Stream stream)
                 where TPixel : unmanaged, IPixel<TPixel>
         {
             Guard.NotNull(image, nameof(image));

src/ImageSharp/Formats/Tga/TgaEncoder.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.PixelFormats;
@@ -32,11 +33,11 @@ namespace SixLabors.ImageSharp.Formats.Tga
         }
 
         /// <inheritdoc/>
-        public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             var encoder = new TgaEncoderCore(this, image.GetMemoryAllocator());
-            return encoder.EncodeAsync(image, stream);
+            return encoder.EncodeAsync(image, stream, cancellationToken);
         }
     }
 }

src/ImageSharp/Formats/Tga/TgaEncoderCore.cs

@@ -5,6 +5,7 @@ using System;
 using System.Buffers.Binary;
 using System.IO;
 using System.Runtime.CompilerServices;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Memory;
@@ -16,7 +17,7 @@ namespace SixLabors.ImageSharp.Formats.Tga
     /// <summary>
     /// Image encoder for writing an image to a stream as a truevision targa image.
     /// </summary>
-    internal sealed class TgaEncoderCore
+    internal sealed class TgaEncoderCore : IImageEncoderInternals
     {
         /// <summary>
         /// Used for allocating memory during processing operations.
@@ -61,31 +62,8 @@ namespace SixLabors.ImageSharp.Formats.Tga
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="image">The <see cref="ImageFrame{TPixel}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
-        public async Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        /// <param name="cancellationToken">The token to request cancellation.</param>
-                where TPixel : unmanaged, IPixel<TPixel>
+        public void Encode<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
-        {
-            if (stream.CanSeek)
-            {
-                this.Encode(image, stream);
-            }
-            else
-            {
-                using (var ms = new MemoryStream())
-                {
-                    this.Encode(image, ms);
-                    ms.Position = 0;
-                    await ms.CopyToAsync(stream).ConfigureAwait(false);
-                }
-            }
-        }
-
-        /// <summary>
-        /// Encodes the image to the specified stream from the <see cref="ImageFrame{TPixel}"/>.
-        /// </summary>
-        /// <typeparam name="TPixel">The pixel format.</typeparam>
-        /// <param name="image">The <see cref="ImageFrame{TPixel}"/> to encode from.</param>
-        /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
-        public void Encode<TPixel>(Image<TPixel> image, Stream stream)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             Guard.NotNull(image, nameof(image));

src/ImageSharp/Image.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Formats;
@@ -106,12 +107,23 @@ namespace SixLabors.ImageSharp
         /// <exception cref="ArgumentNullException">Thrown if the stream or encoder is null.</exception>
         /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
         public Task SaveAsync(Stream stream, IImageEncoder encoder)
+            => this.SaveAsync(stream, encoder, default);
+
+        /// <summary>
+        /// Saves the image to the given stream using the given image encoder.
+        /// </summary>
+        /// <param name="stream">The stream to save the image to.</param>
+        /// <param name="encoder">The encoder to save the image with.</param>
+        /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
+        /// <exception cref="ArgumentNullException">Thrown if the stream or encoder is null.</exception>
+        /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
+        public Task SaveAsync(Stream stream, IImageEncoder encoder, CancellationToken cancellationToken)
         {
             Guard.NotNull(stream, nameof(stream));
             Guard.NotNull(encoder, nameof(encoder));
             this.EnsureNotDisposed();
 
-            return this.AcceptVisitorAsync(new EncodeVisitor(encoder, stream));
+            return this.AcceptVisitorAsync(new EncodeVisitor(encoder, stream), cancellationToken);
         }
 
         /// <summary>
@@ -162,7 +174,8 @@ namespace SixLabors.ImageSharp
         /// with the pixel type of the image.
         /// </summary>
         /// <param name="visitor">The visitor.</param>
-        internal abstract Task AcceptAsync(IImageVisitorAsync visitor);
+        /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
+        internal abstract Task AcceptAsync(IImageVisitorAsync visitor, CancellationToken cancellationToken);
 
         private class EncodeVisitor : IImageVisitor, IImageVisitorAsync
         {
@@ -179,8 +192,8 @@ namespace SixLabors.ImageSharp
             public void Visit<TPixel>(Image<TPixel> image)
                 where TPixel : unmanaged, IPixel<TPixel> => this.encoder.Encode(image, this.stream);
 
-            public Task VisitAsync<TPixel>(Image<TPixel> image)
+            public Task VisitAsync<TPixel>(Image<TPixel> image, CancellationToken cancellationToken)
-                where TPixel : unmanaged, IPixel<TPixel> => this.encoder.EncodeAsync(image, this.stream);
+                where TPixel : unmanaged, IPixel<TPixel> => this.encoder.EncodeAsync(image, this.stream, cancellationToken);
         }
     }
 }

src/ImageSharp/Image{TPixel}.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.CompilerServices;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Formats;
@@ -290,11 +291,11 @@ namespace SixLabors.ImageSharp
         }
 
         /// <inheritdoc />
-        internal override Task AcceptAsync(IImageVisitorAsync visitor)
+        internal override Task AcceptAsync(IImageVisitorAsync visitor, CancellationToken cancellationToken)
         {
             this.EnsureNotDisposed();
 
-            return visitor.VisitAsync(this);
+            return visitor.VisitAsync(this, cancellationToken);
         }
 
         /// <summary>

tests/ImageSharp.Tests/Image/ImageTests.Identify.cs

@@ -172,7 +172,6 @@ namespace SixLabors.ImageSharp.Tests
                 Assert.Equal(ExpectedImageSize, info.Size());
             }
 
-
             [Fact]
             public async Task FromStreamAsync_CustomConfiguration()
             {

tests/ImageSharp.Tests/TestFormat.cs

@@ -270,7 +270,7 @@ namespace SixLabors.ImageSharp.Tests
                 // TODO record this happened so we can verify it.
             }
 
-            public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+            public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
                where TPixel : unmanaged, IPixel<TPixel>
             {
                 // TODO record this happened so we can verify it.

tests/ImageSharp.Tests/TestUtilities/ReferenceCodecs/SystemDrawingReferenceEncoder.cs

@@ -3,6 +3,7 @@
 
 using System.Drawing.Imaging;
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Formats;
 using SixLabors.ImageSharp.PixelFormats;
@@ -31,7 +32,7 @@ namespace SixLabors.ImageSharp.Tests.TestUtilities.ReferenceCodecs
             }
         }
 
-        public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream)
+        public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             using (System.Drawing.Bitmap sdBitmap = SystemDrawingBridge.To32bppArgbSystemDrawingBitmap(image))