Simplify metadata API

src/ImageSharp/Common/Helpers/ImageMaths.cs

@@ -44,7 +44,7 @@ namespace SixLabors.ImageSharp
         /// <param name="bitDepth">The bit depth.</param>
         /// <returns>The <see cref="int"/></returns>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static int GetColorCountForBitDepth(int bitDepth) => (int)Math.Pow(2, bitDepth);
+        public static int GetColorCountForBitDepth(int bitDepth) => 1 << bitDepth;
 
         /// <summary>
         /// Implementation of 1D Gaussian G(x) function

src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs

@@ -537,8 +537,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp
             this.metaData = meta;
 
             short bitsPerPixel = this.infoHeader.BitsPerPixel;
-            var bmpMetaData = new BmpMetaData();
-            this.metaData.AddOrUpdateFormatMetaData(BmpFormat.Instance, bmpMetaData);
+            var bmpMetaData = this.metaData.GetFormatMetaData(BmpFormat.Instance);
 
             // We can only encode at these bit rates so far.
             if (bitsPerPixel.Equals((short)BmpBitsPerPixel.Pixel24)

src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs

@@ -48,7 +48,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp
             Guard.NotNull(image, nameof(image));
             Guard.NotNull(stream, nameof(stream));
 
-            BmpMetaData bmpMetaData = image.MetaData.GetOrAddFormatMetaData(BmpFormat.Instance);
+            BmpMetaData bmpMetaData = image.MetaData.GetFormatMetaData(BmpFormat.Instance);
             this.bitsPerPixel = this.bitsPerPixel ?? bmpMetaData.BitsPerPixel;
 
             short bpp = (short)this.bitsPerPixel;

src/ImageSharp/Formats/Gif/GifDecoderCore.cs

@@ -164,7 +164,6 @@ namespace SixLabors.ImageSharp.Formats.Gif
                 this.globalColorTable?.Dispose();
             }
 
-            image?.MetaData.AddOrUpdateFormatMetaData(GifFormat.Instance, this.gifMetaData);
             return image;
         }
 
@@ -224,7 +223,6 @@ namespace SixLabors.ImageSharp.Formats.Gif
                 this.globalColorTable?.Dispose();
             }
 
-            this.metaData.AddOrUpdateFormatMetaData(GifFormat.Instance, this.gifMetaData);
             return new ImageInfo(
                 new PixelTypeInfo(this.logicalScreenDescriptor.BitsPerPixel),
                 this.logicalScreenDescriptor.Width,
@@ -542,7 +540,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         private void SetFrameMetaData(ImageFrameMetaData meta)
         {
-            var gifMeta = new GifFrameMetaData();
+            GifFrameMetaData gifMeta = meta.GetFormatMetaData(GifFormat.Instance);
             if (this.graphicsControlExtension.DelayTime > 0)
             {
                 gifMeta.FrameDelay = this.graphicsControlExtension.DelayTime;
@@ -561,7 +559,6 @@ namespace SixLabors.ImageSharp.Formats.Gif
             }
 
             gifMeta.DisposalMethod = this.graphicsControlExtension.DisposalMethod;
-            meta.AddOrUpdateFormatMetaData(GifFormat.Instance, gifMeta);
         }
 
         /// <summary>
@@ -605,12 +602,10 @@ namespace SixLabors.ImageSharp.Formats.Gif
             }
 
             this.metaData = meta;
-            this.gifMetaData = new GifMetaData
-            {
-                ColorTableMode = this.logicalScreenDescriptor.GlobalColorTableFlag
-                ? GifColorTableMode.Global
-                : GifColorTableMode.Local
-            };
+            this.gifMetaData = meta.GetFormatMetaData(GifFormat.Instance);
+            this.gifMetaData.ColorTableMode = this.logicalScreenDescriptor.GlobalColorTableFlag
+            ? GifColorTableMode.Global
+            : GifColorTableMode.Local;
 
             if (this.logicalScreenDescriptor.GlobalColorTableFlag)
             {

src/ImageSharp/Formats/Gif/GifEncoderCore.cs

@@ -86,7 +86,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
             Guard.NotNull(image, nameof(image));
             Guard.NotNull(stream, nameof(stream));
 
-            this.gifMetaData = image.MetaData.GetOrAddFormatMetaData(GifFormat.Instance);
+            this.gifMetaData = image.MetaData.GetFormatMetaData(GifFormat.Instance);
             this.colorTableMode = this.colorTableMode ?? this.gifMetaData.ColorTableMode;
             bool useGlobalTable = this.colorTableMode.Equals(GifColorTableMode.Global);
 
@@ -143,7 +143,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
             for (int i = 0; i < image.Frames.Count; i++)
             {
                 ImageFrame<TPixel> frame = image.Frames[i];
-                GifFrameMetaData frameMetaData = frame.MetaData.GetOrAddFormatMetaData(GifFormat.Instance);
+                GifFrameMetaData frameMetaData = frame.MetaData.GetFormatMetaData(GifFormat.Instance);
                 this.WriteGraphicalControlExtension(frameMetaData, transparencyIndex, stream);
                 this.WriteImageDescriptor(frame, false, stream);
 
@@ -169,7 +169,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
             GifFrameMetaData previousMeta = null;
             foreach (ImageFrame<TPixel> frame in image.Frames)
             {
-                GifFrameMetaData meta = frame.MetaData.GetOrAddFormatMetaData(GifFormat.Instance);
+                GifFrameMetaData meta = frame.MetaData.GetFormatMetaData(GifFormat.Instance);
                 if (quantized is null)
                 {
                     // Allow each frame to be encoded at whatever color depth the frame designates if set.

src/ImageSharp/Formats/Png/PngDecoderCore.cs

@@ -217,8 +217,7 @@ namespace SixLabors.ImageSharp.Formats.Png
             where TPixel : struct, IPixel<TPixel>
         {
             var metaData = new ImageMetaData();
-            var pngMetaData = new PngMetaData();
-            metaData.AddOrUpdateFormatMetaData(PngFormat.Instance, pngMetaData);
+            var pngMetaData = metaData.GetFormatMetaData(PngFormat.Instance);
             this.currentStream = stream;
             this.currentStream.Skip(8);
             Image<TPixel> image = null;
@@ -308,8 +307,7 @@ namespace SixLabors.ImageSharp.Formats.Png
         public IImageInfo Identify(Stream stream)
         {
             var metaData = new ImageMetaData();
-            var pngMetaData = new PngMetaData();
-            metaData.AddOrUpdateFormatMetaData(PngFormat.Instance, pngMetaData);
+            var pngMetaData = metaData.GetFormatMetaData(PngFormat.Instance);
             this.currentStream = stream;
             this.currentStream.Skip(8);
             try

src/ImageSharp/Formats/Png/PngEncoderCore.cs

@@ -181,7 +181,7 @@ namespace SixLabors.ImageSharp.Formats.Png
             this.height = image.Height;
 
             // Always take the encoder options over the metadata values.
-            PngMetaData pngMetaData = image.MetaData.GetOrAddFormatMetaData(PngFormat.Instance);
+            PngMetaData pngMetaData = image.MetaData.GetFormatMetaData(PngFormat.Instance);
             this.gamma = this.gamma ?? pngMetaData.Gamma;
             this.writeGamma = this.gamma > 0;
             this.pngColorType = this.pngColorType ?? pngMetaData.ColorType;

src/ImageSharp/MetaData/ImageFrameMetaData.cs

@@ -44,27 +44,6 @@ namespace SixLabors.ImageSharp.MetaData
         /// <returns>The cloned instance.</returns>
         public ImageFrameMetaData Clone() => new ImageFrameMetaData(this);
 
-        /// <summary>
-        /// Adds or updates the specified key and value to the <see cref="ImageMetaData"/>.
-        /// </summary>
-        /// <typeparam name="TFormatMetaData">The type of format metadata.</typeparam>
-        /// <typeparam name="TFormatFrameMetaData">The type of format frame metadata.</typeparam>
-        /// <param name="key">The key of the metadata to add.</param>
-        /// <param name="value">The value of the element to add.</param>
-        /// <exception cref="ArgumentNullException">key is null.</exception>
-        /// <exception cref="ArgumentNullException">value is null.</exception>
-        /// <exception cref="ArgumentException">An element with the same key already exists in the <see cref="ImageMetaData"/>.</exception>
-        public void AddOrUpdateFormatMetaData<TFormatMetaData, TFormatFrameMetaData>(
-            IImageFormat<TFormatMetaData, TFormatFrameMetaData> key,
-            TFormatFrameMetaData value)
-            where TFormatMetaData : class
-            where TFormatFrameMetaData : class
-        {
-            // Don't think this needs to be threadsafe.
-            Guard.NotNull(value, nameof(value));
-            this.formatMetaData[key] = value;
-        }
-
         /// <summary>
         /// Gets the metadata value associated with the specified key.
         /// </summary>
@@ -74,7 +53,7 @@ namespace SixLabors.ImageSharp.MetaData
         /// <returns>
         /// The <typeparamref name="TFormatFrameMetaData"/>.
         /// </returns>
-        public TFormatFrameMetaData GetOrAddFormatMetaData<TFormatMetaData, TFormatFrameMetaData>(IImageFormat<TFormatMetaData, TFormatFrameMetaData> key)
+        public TFormatFrameMetaData GetFormatMetaData<TFormatMetaData, TFormatFrameMetaData>(IImageFormat<TFormatMetaData, TFormatFrameMetaData> key)
             where TFormatMetaData : class
             where TFormatFrameMetaData : class
         {
@@ -84,7 +63,7 @@ namespace SixLabors.ImageSharp.MetaData
             }
 
             TFormatFrameMetaData newMeta = key.CreateDefaultFormatFrameMetaData();
-            this.AddOrUpdateFormatMetaData(key, newMeta);
+            this.formatMetaData[key] = newMeta;
             return newMeta;
         }
     }

src/ImageSharp/MetaData/ImageMetaData.cs

@@ -131,23 +131,6 @@ namespace SixLabors.ImageSharp.MetaData
         /// </summary>
         public IList<ImageProperty> Properties { get; } = new List<ImageProperty>();
 
-        /// <summary>
-        /// Adds or updates the specified key and value to the <see cref="ImageMetaData"/>.
-        /// </summary>
-        /// <typeparam name="TFormatMetaData">The type of format metadata.</typeparam>
-        /// <param name="key">The key of the metadata to add.</param>
-        /// <param name="value">The value of the element to add.</param>
-        /// <exception cref="ArgumentNullException">key is null.</exception>
-        /// <exception cref="ArgumentNullException">value is null.</exception>
-        /// <exception cref="ArgumentException">An element with the same key already exists in the <see cref="ImageMetaData"/>.</exception>
-        public void AddOrUpdateFormatMetaData<TFormatMetaData>(IImageFormat<TFormatMetaData> key, TFormatMetaData value)
-            where TFormatMetaData : class
-        {
-            // Don't think this needs to be threadsafe.
-            Guard.NotNull(value, nameof(value));
-            this.formatMetaData[key] = value;
-        }
-
         /// <summary>
         /// Gets the metadata value associated with the specified key.
         /// </summary>
@@ -156,7 +139,7 @@ namespace SixLabors.ImageSharp.MetaData
         /// <returns>
         /// The <typeparamref name="TFormatMetaData"/>.
         /// </returns>
-        public TFormatMetaData GetOrAddFormatMetaData<TFormatMetaData>(IImageFormat<TFormatMetaData> key)
+        public TFormatMetaData GetFormatMetaData<TFormatMetaData>(IImageFormat<TFormatMetaData> key)
              where TFormatMetaData : class
         {
             if (this.formatMetaData.TryGetValue(key, out object meta))
@@ -165,7 +148,7 @@ namespace SixLabors.ImageSharp.MetaData
             }
 
             TFormatMetaData newMeta = key.CreateDefaultFormatMetaData();
-            this.AddOrUpdateFormatMetaData(key, newMeta);
+            this.formatMetaData[key] = newMeta;
             return newMeta;
         }
 

tests/ImageSharp.Tests/Formats/Bmp/BmpEncoderTests.cs

@@ -80,7 +80,7 @@ namespace SixLabors.ImageSharp.Tests
                     memStream.Position = 0;
                     using (var output = Image.Load<Rgba32>(memStream))
                     {
-                        BmpMetaData meta = output.MetaData.GetOrAddFormatMetaData(BmpFormat.Instance);
+                        BmpMetaData meta = output.MetaData.GetFormatMetaData(BmpFormat.Instance);
 
                         Assert.Equal(bmpBitsPerPixel, meta.BitsPerPixel);
                     }

tests/ImageSharp.Tests/Formats/Gif/GifEncoderTests.cs

@@ -189,8 +189,8 @@ namespace SixLabors.ImageSharp.Tests.Formats.Gif
                 inStream.Position = 0;
 
                 var image = Image.Load(inStream);
-                GifMetaData metaData = image.MetaData.GetOrAddFormatMetaData(GifFormat.Instance);
-                GifFrameMetaData frameMetaData = image.Frames.RootFrame.MetaData.GetOrAddFormatMetaData(GifFormat.Instance);
+                GifMetaData metaData = image.MetaData.GetFormatMetaData(GifFormat.Instance);
+                GifFrameMetaData frameMetaData = image.Frames.RootFrame.MetaData.GetFormatMetaData(GifFormat.Instance);
                 GifColorTableMode colorMode = metaData.ColorTableMode;
                 var encoder = new GifEncoder()
                 {
@@ -204,7 +204,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Gif
                 outStream.Position = 0;
                 var clone = Image.Load(outStream);
 
-                GifMetaData cloneMetaData = clone.MetaData.GetOrAddFormatMetaData<GifMetaData>(GifFormat.Instance);
+                GifMetaData cloneMetaData = clone.MetaData.GetFormatMetaData<GifMetaData>(GifFormat.Instance);
                 Assert.Equal(metaData.ColorTableMode, cloneMetaData.ColorTableMode);
 
                 // Gifiddle and Cyotek GifInfo say this image has 64 colors.
@@ -212,8 +212,8 @@ namespace SixLabors.ImageSharp.Tests.Formats.Gif
 
                 for (int i = 0; i < image.Frames.Count; i++)
                 {
-                    GifFrameMetaData ifm = image.Frames[i].MetaData.GetOrAddFormatMetaData(GifFormat.Instance);
-                    GifFrameMetaData cifm = clone.Frames[i].MetaData.GetOrAddFormatMetaData(GifFormat.Instance);
+                    GifFrameMetaData ifm = image.Frames[i].MetaData.GetFormatMetaData(GifFormat.Instance);
+                    GifFrameMetaData cifm = clone.Frames[i].MetaData.GetFormatMetaData(GifFormat.Instance);
 
                     Assert.Equal(ifm.ColorTableLength, cifm.ColorTableLength);
                     Assert.Equal(ifm.FrameDelay, cifm.FrameDelay);

tests/ImageSharp.Tests/Formats/Png/PngEncoderTests.cs

@@ -228,7 +228,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
                                                : image;
 
                     float paletteToleranceHack = 80f / paletteSize;
-                    paletteToleranceHack = paletteToleranceHack * paletteToleranceHack;
+                    paletteToleranceHack *= paletteToleranceHack;
                     ImageComparer comparer = pngColorType == PngColorType.Palette
                                                  ? ImageComparer.Tolerant(ToleranceThresholdForPaletteEncoder * paletteToleranceHack)
                                                  : ImageComparer.Exact;
@@ -314,7 +314,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
                     memStream.Position = 0;
                     using (var output = Image.Load<Rgba32>(memStream))
                     {
-                        PngMetaData meta = output.MetaData.GetOrAddFormatMetaData(PngFormat.Instance);
+                        PngMetaData meta = output.MetaData.GetFormatMetaData(PngFormat.Instance);
 
                         Assert.Equal(pngBitDepth, meta.BitDepth);
                     }

tests/ImageSharp.Tests/MetaData/ImageFrameMetaDataTests.cs

@@ -19,18 +19,14 @@ namespace SixLabors.ImageSharp.Tests
             const int colorTableLength = 128;
             const GifDisposalMethod disposalMethod = GifDisposalMethod.RestoreToBackground;
 
-            var gifFrameMetaData = new GifFrameMetaData
-            {
-                FrameDelay = frameDelay,
-                ColorTableLength = colorTableLength,
-                DisposalMethod = disposalMethod
-            };
-
             var metaData = new ImageFrameMetaData();
-            metaData.AddOrUpdateFormatMetaData(GifFormat.Instance, gifFrameMetaData);
+            GifFrameMetaData gifFrameMetaData = metaData.GetFormatMetaData(GifFormat.Instance);
+            gifFrameMetaData.FrameDelay = frameDelay;
+            gifFrameMetaData.ColorTableLength = colorTableLength;
+            gifFrameMetaData.DisposalMethod = disposalMethod;
 
             var clone = new ImageFrameMetaData(metaData);
-            GifFrameMetaData cloneGifFrameMetaData = clone.GetOrAddFormatMetaData(GifFormat.Instance);
+            GifFrameMetaData cloneGifFrameMetaData = clone.GetFormatMetaData(GifFormat.Instance);
 
             Assert.Equal(frameDelay, cloneGifFrameMetaData.FrameDelay);
             Assert.Equal(colorTableLength, cloneGifFrameMetaData.ColorTableLength);