Introduce InliningOptions

src/ImageSharp/Common/Helpers/InliningOptions.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+// Uncomment this for verbose profiler results:
+// #define PROFILING
+using System.Runtime.CompilerServices;
+
+namespace SixLabors.ImageSharp
+{
+    /// <summary>
+    /// Global inlining options. Helps temporally disable inling for better profiler output.
+    /// </summary>
+    internal static class InliningOptions
+    {
+#if PROFILING
+        public const MethodImplOptions ShortMethod = 0;
+#else
+        public const MethodImplOptions ShortMethod = MethodImplOptions.AggressiveInlining;
+#endif
+        public const MethodImplOptions ColdPath = MethodImplOptions.NoInlining;
+    }
+}

src/ImageSharp/Formats/Jpeg/JpegThrowHelper.cs

@@ -0,0 +1,26 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System.Runtime.CompilerServices;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg
+{
+    internal static class JpegThrowHelper
+    {
+        /// <summary>
+        /// Cold path optimization for throwing <see cref="ImageFormatException"/>-s
+        /// </summary>
+        /// <param name="errorMessage">The error message for the exception</param>
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        public static void ThrowImageFormatException(string errorMessage)
+        {
+            throw new ImageFormatException(errorMessage);
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        public static void ThrowBadHuffmanCode()
+        {
+            throw new ImageFormatException("Bad Huffman code.");
+        }
+    }
+}

src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/ScanDecoder.cs

@@ -665,7 +665,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
             }
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(InliningOptions.ShortMethod)]
         private int GetBits(int n)
         {
             if (this.codeBits < n)
@@ -680,7 +680,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
             return (int)k;
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(InliningOptions.ShortMethod)]
         private int GetBit()
         {
             if (this.codeBits < 1)
@@ -695,7 +695,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
             return (int)(k & 0x80000000);
         }
 
-        [MethodImpl(MethodImplOptions.NoInlining)]
+        [MethodImpl(InliningOptions.ColdPath)]
         private void FillBuffer()
         {
             // Attempt to load at least the minimum nbumber of required bits into the buffer.
@@ -748,7 +748,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
             while (this.codeBits <= 24);
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(InliningOptions.ShortMethod)]
         private int DecodeHuffman(ref PdfJsHuffmanTable table)
         {
             this.CheckBits();
@@ -773,7 +773,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
             return this.DecodeHuffmanSlow(ref table);
         }
 
-        [MethodImpl(MethodImplOptions.NoInlining)]
+        [MethodImpl(InliningOptions.ColdPath)]
         private int DecodeHuffmanSlow(ref PdfJsHuffmanTable table)
         {
             // Naive test is to shift the code_buffer down so k bits are
@@ -813,7 +813,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
             return table.Values[c];
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(InliningOptions.ShortMethod)]
         private int ExtendReceive(int n)
         {
             if (this.codeBits < n)
@@ -829,7 +829,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
             return (int)(k + (Bias[n] & ~sgn));
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(InliningOptions.ShortMethod)]
         private void CheckBits()
         {
             if (this.codeBits < 16)
@@ -838,10 +838,10 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
             }
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(InliningOptions.ShortMethod)]
         private int PeekBits() => (int)((this.codeBuffer >> (32 - FastBits)) & ((1 << FastBits) - 1));
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(InliningOptions.ShortMethod)]
         private bool ContinueOnMcuComplete()
         {
             if (--this.todo > 0)
@@ -871,14 +871,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
             return true;
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(InliningOptions.ShortMethod)]
         private bool HasRestart()
         {
             byte m = this.marker;
             return m >= JpegConstants.Markers.RST0 && m <= JpegConstants.Markers.RST7;
         }
 
-        [MethodImpl(MethodImplOptions.NoInlining)]
         private void Reset()
         {
             this.codeBits = 0;