Remove BitConverter from EndianBinaryWriter & add Floating point tests

src/ImageSharp/IO/EndianBinaryWriter.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
+using System.Buffers.Binary;
 using System.IO;
 using System.Text;
 
@@ -23,6 +24,11 @@ namespace SixLabors.ImageSharp.IO
         /// </summary>
         private readonly char[] charBuffer = new char[1];
 
+        /// <summary>
+        /// The endianness used to write the data
+        /// </summary>
+        private readonly Endianness endianness;
+
         /// <summary>
         /// Whether or not this writer has been disposed yet.
         /// </summary>
@@ -55,8 +61,8 @@ namespace SixLabors.ImageSharp.IO
             Guard.IsTrue(stream.CanWrite, nameof(stream), "Stream isn't writable");
 
             this.BaseStream = stream;
-            this.BitConverter = EndianBitConverter.GetConverter(endianness);
             this.Encoding = encoding;
+            this.endianness = endianness;
         }
 
         /// <summary>
@@ -69,11 +75,6 @@ namespace SixLabors.ImageSharp.IO
         /// </summary>
         public Stream BaseStream { get; }
 
-        /// <summary>
-        /// Gets the bit converter used to write values to the stream
-        /// </summary>
-        internal EndianBitConverter BitConverter { get; }
-
         /// <summary>
         /// Closes the writer, including the underlying stream.
         /// </summary>
@@ -108,7 +109,8 @@ namespace SixLabors.ImageSharp.IO
         /// <param name="value">The value to write</param>
         public void Write(bool value)
         {
-            this.BitConverter.CopyBytes(value, this.buffer, 0);
+            this.buffer[0] = value ? (byte)1 : (byte)0;
+
             this.WriteInternal(this.buffer, 1);
         }
 
@@ -119,7 +121,15 @@ namespace SixLabors.ImageSharp.IO
         /// <param name="value">The value to write</param>
         public void Write(short value)
         {
-            this.BitConverter.CopyBytes(value, this.buffer, 0);
+            if (this.endianness == Endianness.BigEndian)
+            {
+                BinaryPrimitives.WriteInt16BigEndian(this.buffer, value);
+            }
+            else
+            {
+                BinaryPrimitives.WriteInt16LittleEndian(this.buffer, value);
+            }
+
             this.WriteInternal(this.buffer, 2);
         }
 
@@ -130,7 +140,15 @@ namespace SixLabors.ImageSharp.IO
         /// <param name="value">The value to write</param>
         public void Write(int value)
         {
-            this.BitConverter.CopyBytes(value, this.buffer, 0);
+            if (this.endianness == Endianness.BigEndian)
+            {
+                BinaryPrimitives.WriteInt32BigEndian(this.buffer, value);
+            }
+            else
+            {
+                BinaryPrimitives.WriteInt32LittleEndian(this.buffer, value);
+            }
+
             this.WriteInternal(this.buffer, 4);
         }
 
@@ -141,7 +159,15 @@ namespace SixLabors.ImageSharp.IO
         /// <param name="value">The value to write</param>
         public void Write(long value)
         {
-            this.BitConverter.CopyBytes(value, this.buffer, 0);
+            if (this.endianness == Endianness.BigEndian)
+            {
+                BinaryPrimitives.WriteInt64BigEndian(this.buffer, value);
+            }
+            else
+            {
+                BinaryPrimitives.WriteInt64LittleEndian(this.buffer, value);
+            }
+
             this.WriteInternal(this.buffer, 8);
         }
 
@@ -152,7 +178,15 @@ namespace SixLabors.ImageSharp.IO
         /// <param name="value">The value to write</param>
         public void Write(ushort value)
         {
-            this.BitConverter.CopyBytes(value, this.buffer, 0);
+            if (this.endianness == Endianness.BigEndian)
+            {
+                BinaryPrimitives.WriteUInt16BigEndian(this.buffer, value);
+            }
+            else
+            {
+                BinaryPrimitives.WriteUInt16LittleEndian(this.buffer, value);
+            }
+
             this.WriteInternal(this.buffer, 2);
         }
 
@@ -163,7 +197,15 @@ namespace SixLabors.ImageSharp.IO
         /// <param name="value">The value to write</param>
         public void Write(uint value)
         {
-            this.BitConverter.CopyBytes(value, this.buffer, 0);
+            if (this.endianness == Endianness.BigEndian)
+            {
+                BinaryPrimitives.WriteUInt32BigEndian(this.buffer, value);
+            }
+            else
+            {
+                BinaryPrimitives.WriteUInt32LittleEndian(this.buffer, value);
+            }
+
             this.WriteInternal(this.buffer, 4);
         }
 
@@ -174,7 +216,15 @@ namespace SixLabors.ImageSharp.IO
         /// <param name="value">The value to write</param>
         public void Write(ulong value)
         {
-            this.BitConverter.CopyBytes(value, this.buffer, 0);
+            if (this.endianness == Endianness.BigEndian)
+            {
+                BinaryPrimitives.WriteUInt64BigEndian(this.buffer, value);
+            }
+            else
+            {
+                BinaryPrimitives.WriteUInt64LittleEndian(this.buffer, value);
+            }
+
             this.WriteInternal(this.buffer, 8);
         }
 
@@ -183,10 +233,9 @@ namespace SixLabors.ImageSharp.IO
         /// for this writer. 4 bytes are written.
         /// </summary>
         /// <param name="value">The value to write</param>
-        public void Write(float value)
+        public unsafe void Write(float value)
         {
-            this.BitConverter.CopyBytes(value, this.buffer, 0);
-            this.WriteInternal(this.buffer, 4);
+            this.Write(*((int*)&value));
         }
 
         /// <summary>
@@ -194,10 +243,9 @@ namespace SixLabors.ImageSharp.IO
         /// for this writer. 8 bytes are written.
         /// </summary>
         /// <param name="value">The value to write</param>
-        public void Write(double value)
+        public unsafe void Write(double value)
         {
-            this.BitConverter.CopyBytes(value, this.buffer, 0);
-            this.WriteInternal(this.buffer, 8);
+            this.Write(*((long*)&value));
         }
 
         /// <summary>

src/ImageSharp/IO/EndianBitConverter.GetBytes.cs

@@ -121,17 +121,5 @@ namespace SixLabors.ImageSharp.IO
         {
             return this.GetBytes(*((int*)&value));
         }
-
-        /// <summary>
-        /// Returns the specified decimal value as an array of bytes.
-        /// </summary>
-        /// <param name="value">The number to convert.</param>
-        /// <returns>An array of bytes with length 16.</returns>
-        public byte[] GetBytes(decimal value)
-        {
-            byte[] result = new byte[16];
-            this.CopyBytes(value, result, 0);
-            return result;
-        }
     }
 }

tests/ImageSharp.Tests/IO/EndianBinaryReaderWriterTests.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
+using System;
 using System.IO;
 using SixLabors.ImageSharp.IO;
 using Xunit;
@@ -9,6 +10,44 @@ namespace SixLabors.ImageSharp.Tests.IO
 {
     public class EndianBinaryReaderWriterTests
     {
+        [Fact]
+        public void RoundtripSingles()
+        {
+            foreach ((Endianness endianness, byte[] bytes) in new[] {
+                (Endianness.BigEndian, new byte[] { 64, 73, 15, 219 }),
+                (Endianness.LittleEndian, new byte[] { 219, 15, 73, 64 })
+            })
+            {
+                var stream = new MemoryStream();
+
+                using (var writer = new EndianBinaryWriter(endianness, stream))
+                {
+                    writer.Write((float)Math.PI);
+
+                    Assert.Equal(bytes, stream.ToArray());
+                }
+            }
+        }
+
+        [Fact]
+        public void RoundtripDoubles()
+        {
+            foreach ((Endianness endianness, byte[] bytes) in new[] {
+                (Endianness.BigEndian, new byte[] { 64, 9, 33, 251, 84, 68, 45, 24 }),
+                (Endianness.LittleEndian, new byte[] { 24, 45, 68, 84, 251, 33, 9, 64 })
+            })
+            {
+                var stream = new MemoryStream();
+
+                using (var writer = new EndianBinaryWriter(endianness, stream))
+                {
+                    writer.Write(Math.PI);
+
+                    Assert.Equal(bytes, stream.ToArray());
+                }
+            }
+        }
+
         /// <summary>
         /// Ensures that the data written through a binary writer can be read back through the reader
         /// </summary>
@@ -55,4 +94,4 @@ namespace SixLabors.ImageSharp.Tests.IO
             }
         }
     }
-}
+}