Refactor JpegPixelArea to delegate memory management to Buffer2D<T>.

src/ImageSharp/Formats/Jpeg/Components/Decoder/JpegPixelArea.cs

@@ -4,7 +4,6 @@
 // </copyright>
 namespace ImageSharp.Formats.Jpg
 {
-    using System.Buffers;
     using System.Runtime.CompilerServices;
 
     /// <summary>
@@ -15,20 +14,20 @@ namespace ImageSharp.Formats.Jpg
         /// <summary>
         /// Initializes a new instance of the <see cref="JpegPixelArea" /> struct from existing data.
         /// </summary>
-        /// <param name="pixels">The pixel array</param>
-        /// <param name="striede">The stride</param>
+        /// <param name="pixels">The pixel buffer</param>
+        /// <param name="stride">The stride</param>
         /// <param name="offset">The offset</param>
-        public JpegPixelArea(byte[] pixels, int striede, int offset)
+        public JpegPixelArea(Buffer2D<byte> pixels, int stride, int offset)
         {
-            this.Stride = striede;
+            this.Stride = stride;
             this.Pixels = pixels;
             this.Offset = offset;
         }
 
         /// <summary>
-        /// Gets the pixels.
+        /// Gets the pixels buffer.
         /// </summary>
-        public byte[] Pixels { get; private set; }
+        public Buffer2D<byte> Pixels { get; private set; }
 
         /// <summary>
         /// Gets a value indicating whether the instance has been initalized. (Is not default(JpegPixelArea))
@@ -36,21 +35,19 @@ namespace ImageSharp.Formats.Jpg
         public bool IsInitialized => this.Pixels != null;
 
         /// <summary>
-        /// Gets or the stride.
+        /// Gets the stride.
         /// </summary>
         public int Stride { get; }
 
         /// <summary>
-        /// Gets or the offset.
+        /// Gets the offset.
         /// </summary>
         public int Offset { get; }
 
         /// <summary>
         /// Gets a <see cref="MutableSpan{T}" /> of bytes to the pixel area
         /// </summary>
-        public MutableSpan<byte> Span => new MutableSpan<byte>(this.Pixels, this.Offset);
-
-        private static ArrayPool<byte> BytePool => ArrayPool<byte>.Shared;
+        public MutableSpan<byte> Span => new MutableSpan<byte>(this.Pixels.Array, this.Offset);
 
         /// <summary>
         /// Returns the pixel at (x, y)
@@ -69,21 +66,16 @@ namespace ImageSharp.Formats.Jpg
 
         /// <summary>
         /// Creates a new instance of the <see cref="JpegPixelArea" /> struct.
-        /// Pixel array will be taken from a pool, this instance will be the owner of it's pixel data, therefore
-        /// <see cref="ReturnPooled" /> should be called when the instance is no longer needed.
+        /// Pixel array will be handled by <see cref="Buffer2D{T}"/>, but
+        /// <see cref="ReturnPooled" /> can be called when the instance is no longer needed.
         /// </summary>
         /// <param name="width">The width.</param>
         /// <param name="height">The height.</param>
         /// <returns>A <see cref="JpegPixelArea" /> with pooled data</returns>
-        public static JpegPixelArea CreatePooled(int width, int height)
-        {
-            int size = width * height;
-            byte[] pixels = BytePool.Rent(size);
-            return new JpegPixelArea(pixels, width, 0);
-        }
+        public static JpegPixelArea CreatePooled(int width, int height) => new JpegPixelArea(Buffer2D<byte>.CreateClean(width, height), width, 0);
 
         /// <summary>
-        /// Returns <see cref="Pixels" /> to the pool
+        /// Dispose <see cref="Pixels" />.
         /// </summary>
         public void ReturnPooled()
         {
@@ -92,7 +84,7 @@ namespace ImageSharp.Formats.Jpg
                 return;
             }
 
-            BytePool.Return(this.Pixels);
+            this.Pixels.Dispose();
             this.Pixels = null;
         }
 
@@ -129,7 +121,7 @@ namespace ImageSharp.Formats.Jpg
         public unsafe void LoadColorsFrom(Block8x8F* block, Block8x8F* temp)
         {
             // Level shift by +128, clip to [0, 255], and write to dst.
-            block->CopyColorsTo(new MutableSpan<byte>(this.Pixels, this.Offset), this.Stride, temp);
+            block->CopyColorsTo(new MutableSpan<byte>(this.Pixels.Array, this.Offset), this.Stride, temp);
         }
     }
 }