From 9c96f023fcc59bcdb5e3ea64e9d8f04f8e3ba4f2 Mon Sep 17 00:00:00 2001
From: James Jackson-South <james_south@hotmail.com>
Date: Tue, 22 Jun 2021 11:23:19 +1000
Subject: [PATCH] Remove from Gif

---
 src/ImageSharp/Formats/Gif/GifDecoderCore.cs | 25 ++++++++++----------
 src/ImageSharp/Formats/Gif/GifEncoderCore.cs |  8 ++++---
 2 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/src/ImageSharp/Formats/Gif/GifDecoderCore.cs b/src/ImageSharp/Formats/Gif/GifDecoderCore.cs
index fb3d989d4b..e59dad6826 100644
--- a/src/ImageSharp/Formats/Gif/GifDecoderCore.cs
+++ b/src/ImageSharp/Formats/Gif/GifDecoderCore.cs
@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
+using System.Buffers;
 using System.IO;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
@@ -33,7 +34,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
         /// <summary>
         /// The global color table.
         /// </summary>
-        private IManagedByteBuffer globalColorTable;
+        private IMemoryOwner<byte> globalColorTable;
 
         /// <summary>
         /// The area to restore.
@@ -323,12 +324,12 @@ namespace SixLabors.ImageSharp.Formats.Gif
                     continue;
                 }
 
-                using (IManagedByteBuffer commentsBuffer = this.MemoryAllocator.AllocateManagedByteBuffer(length))
-                {
-                    this.stream.Read(commentsBuffer.Array, 0, length);
-                    string commentPart = GifConstants.Encoding.GetString(commentsBuffer.Array, 0, length);
-                    stringBuilder.Append(commentPart);
-                }
+                using IMemoryOwner<byte> commentsBuffer = this.MemoryAllocator.Allocate<byte>(length);
+                Span<byte> commentsSpan = commentsBuffer.GetSpan();
+
+                this.stream.Read(commentsSpan);
+                string commentPart = GifConstants.Encoding.GetString(commentsSpan);
+                stringBuilder.Append(commentPart);
             }
 
             if (stringBuilder.Length > 0)
@@ -348,7 +349,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
         {
             this.ReadImageDescriptor();
 
-            IManagedByteBuffer localColorTable = null;
+            IMemoryOwner<byte> localColorTable = null;
             Buffer2D<byte> indices = null;
             try
             {
@@ -356,8 +357,8 @@ namespace SixLabors.ImageSharp.Formats.Gif
                 if (this.imageDescriptor.LocalColorTableFlag)
                 {
                     int length = this.imageDescriptor.LocalColorTableSize * 3;
-                    localColorTable = this.Configuration.MemoryAllocator.AllocateManagedByteBuffer(length, AllocationOptions.Clean);
-                    this.stream.Read(localColorTable.Array, 0, length);
+                    localColorTable = this.Configuration.MemoryAllocator.Allocate<byte>(length, AllocationOptions.Clean);
+                    this.stream.Read(localColorTable.GetSpan());
                 }
 
                 indices = this.Configuration.MemoryAllocator.Allocate2D<byte>(this.imageDescriptor.Width, this.imageDescriptor.Height, AllocationOptions.Clean);
@@ -622,10 +623,10 @@ namespace SixLabors.ImageSharp.Formats.Gif
                 int globalColorTableLength = this.logicalScreenDescriptor.GlobalColorTableSize * 3;
                 this.gifMetadata.GlobalColorTableLength = globalColorTableLength;
 
-                this.globalColorTable = this.MemoryAllocator.AllocateManagedByteBuffer(globalColorTableLength, AllocationOptions.Clean);
+                this.globalColorTable = this.MemoryAllocator.Allocate<byte>(globalColorTableLength, AllocationOptions.Clean);
 
                 // Read the global color table data from the stream
-                stream.Read(this.globalColorTable.Array, 0, globalColorTableLength);
+                stream.Read(this.globalColorTable.GetSpan());
             }
         }
     }
diff --git a/src/ImageSharp/Formats/Gif/GifEncoderCore.cs b/src/ImageSharp/Formats/Gif/GifEncoderCore.cs
index 4c881ec3f2..05ea14e9ce 100644
--- a/src/ImageSharp/Formats/Gif/GifEncoderCore.cs
+++ b/src/ImageSharp/Formats/Gif/GifEncoderCore.cs
@@ -470,14 +470,16 @@ namespace SixLabors.ImageSharp.Formats.Gif
             // The maximum number of colors for the bit depth
             int colorTableLength = ColorNumerics.GetColorCountForBitDepth(this.bitDepth) * Unsafe.SizeOf<Rgb24>();
 
-            using IManagedByteBuffer colorTable = this.memoryAllocator.AllocateManagedByteBuffer(colorTableLength, AllocationOptions.Clean);
+            using IMemoryOwner<byte> colorTable = this.memoryAllocator.Allocate<byte>(colorTableLength, AllocationOptions.Clean);
+            Span<byte> colorTableSpan = colorTable.GetSpan();
+
             PixelOperations<TPixel>.Instance.ToRgb24Bytes(
                 this.configuration,
                 image.Palette.Span,
-                colorTable.GetSpan(),
+                colorTableSpan,
                 image.Palette.Length);
 
-            stream.Write(colorTable.Array, 0, colorTableLength);
+            stream.Write(colorTableSpan);
         }
 
         /// <summary>