Use ExifProfile for tiff frame metadata

src/ImageSharp/Formats/Tiff/Ifd/DirectoryReader.cs

@@ -26,7 +26,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
             this.tagReader = new EntryReader(stream);
         }
 
-        public IEnumerable<IExifValue[]> Read()
+        public IEnumerable<ExifProfile> Read()
         {
             if (this.ReadHeader())
             {
@@ -55,13 +55,13 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
             return true;
         }
 
-        private IEnumerable<IExifValue[]> ReadIfds()
+        private IEnumerable<ExifProfile> ReadIfds()
         {
-            var list = new List<IExifValue[]>();
+            var list = new List<ExifProfile>();
             while (this.nextIfdOffset != 0)
             {
                 this.stream.Seek(this.nextIfdOffset);
-                IExifValue[] ifd = this.ReadIfd();
+                ExifProfile ifd = this.ReadIfd();
                 list.Add(ifd);
             }
 
@@ -70,7 +70,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
             return list;
         }
 
-        private IExifValue[] ReadIfd()
+        private ExifProfile ReadIfd()
         {
             long pos = this.stream.Position;
 
@@ -99,7 +99,9 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
                 TiffThrowHelper.ThrowOutOfRange("IFD");
             }
 
-            return entries.ToArray();
+            var profile = new ExifProfile();
+            profile.InitializeInternal(entries);
+            return profile;
         }
     }
 }

src/ImageSharp/Formats/Tiff/TiffDecoderCore.cs

@@ -106,11 +106,11 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
             TiffStream tiffStream = CreateStream(stream);
             var reader = new DirectoryReader(tiffStream);
 
-            IEnumerable<IExifValue[]> directories = reader.Read();
+            IEnumerable<ExifProfile> directories = reader.Read();
 
             var frames = new List<ImageFrame<TPixel>>();
             var framesMetadata = new List<TiffFrameMetadata>();
-            foreach (IExifValue[] ifd in directories)
+            foreach (ExifProfile ifd in directories)
             {
                 ImageFrame<TPixel> frame = this.DecodeFrame<TPixel>(ifd, out TiffFrameMetadata frameMetadata);
                 frames.Add(frame);
@@ -144,13 +144,12 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
             TiffStream tiffStream = CreateStream(stream);
             var reader = new DirectoryReader(tiffStream);
 
-            IEnumerable<IExifValue[]> directories = reader.Read();
+            IEnumerable<ExifProfile> directories = reader.Read();
 
             var framesMetadata = new List<TiffFrameMetadata>();
-            foreach (IExifValue[] ifd in directories)
+            foreach (ExifProfile ifd in directories)
             {
-                var meta = new TiffFrameMetadata();
-                meta.FrameTags.AddRange(ifd);
+                var meta = new TiffFrameMetadata() { FrameTags = ifd };
                 framesMetadata.Add(meta);
             }
 
@@ -200,12 +199,12 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
         /// <returns>
         /// The tiff frame.
         /// </returns>
-        private ImageFrame<TPixel> DecodeFrame<TPixel>(IExifValue[] tags, out TiffFrameMetadata frameMetaData)
+        private ImageFrame<TPixel> DecodeFrame<TPixel>(ExifProfile tags, out TiffFrameMetadata frameMetaData)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             var coreMetadata = new ImageFrameMetadata();
             frameMetaData = coreMetadata.GetTiffMetadata();
-            frameMetaData.FrameTags.AddRange(tags);
+            frameMetaData.FrameTags = tags;
 
             this.VerifyAndParse(frameMetaData);
 

src/ImageSharp/Formats/Tiff/TiffEncoderEntriesCollector.cs

@@ -134,7 +134,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
 
             private void ProcessMetadata(TiffFrameMetadata frameMetadata)
             {
-                foreach (IExifValue entry in frameMetadata.FrameTags)
+                foreach (IExifValue entry in frameMetadata.FrameTags.Values)
                 {
                     // todo: skip subIfd
                     if (entry.DataType == ExifDataType.Ifd)

src/ImageSharp/Formats/Tiff/TiffFrameMetadata.cs

@@ -21,6 +21,8 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
 
         private const TiffPredictor DefaultPredictor = TiffPredictor.None;
 
+        private ExifProfile frameTags;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="TiffFrameMetadata"/> class.
         /// </summary>
@@ -29,9 +31,13 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
         }
 
         /// <summary>
-        /// Gets the Tiff directory tags list.
+        /// Gets the Tiff directory tags.
         /// </summary>
-        public List<IExifValue> FrameTags { get; internal set; } = new List<IExifValue>();
+        public ExifProfile FrameTags
+        {
+            get => this.frameTags ??= new ExifProfile();
+            internal set => this.frameTags = value;
+        }
 
         /// <summary>Gets a general indication of the kind of data contained in this subfile.</summary>
         /// <value>A general indication of the kind of data contained in this subfile.</value>
@@ -241,7 +247,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
         public void ClearMetadata()
         {
             var tags = new List<IExifValue>();
-            foreach (IExifValue entry in this.FrameTags)
+            foreach (IExifValue entry in this.FrameTags.Values)
             {
                 switch ((ExifTagValue)(ushort)entry.Tag)
                 {
@@ -261,19 +267,12 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
                 }
             }
 
-            this.FrameTags = tags;
+            var profile = new ExifProfile();
+            profile.InitializeInternal(tags);
+            this.FrameTags = profile;
         }
 
         /// <inheritdoc/>
-        public IDeepCloneable DeepClone()
-        {
-            var tags = new List<IExifValue>();
-            foreach (IExifValue entry in this.FrameTags)
-            {
-                tags.Add(entry.DeepClone());
-            }
-
-            return new TiffFrameMetadata() { FrameTags = tags };
-        }
+        public IDeepCloneable DeepClone() => new TiffFrameMetadata() { FrameTags = this.FrameTags.DeepClone() };
     }
 }

src/ImageSharp/Formats/Tiff/TiffFrameMetadataExtensions.cs

@@ -31,7 +31,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
         public static bool TryGetArray<T>(this TiffFrameMetadata meta, ExifTag tag, out T[] result)
             where T : struct
         {
-            foreach (IExifValue entry in meta.FrameTags)
+            foreach (IExifValue entry in meta.FrameTags.Values)
             {
                 if (entry.Tag == tag)
                 {
@@ -65,7 +65,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
 
         public static string GetString(this TiffFrameMetadata meta, ExifTag tag)
         {
-            foreach (IExifValue entry in meta.FrameTags)
+            foreach (IExifValue entry in meta.FrameTags.Values)
             {
                 if (entry.Tag == tag)
                 {
@@ -80,13 +80,8 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
             return null;
         }
 
-        public static bool SetString(this TiffFrameMetadata meta, ExifTag tag, string value)
-        {
-            IExifValue obj = FindOrCreate(meta, tag);
-            DebugGuard.IsTrue(obj.DataType == ExifDataType.Ascii, "Expected string entry");
-
-            return obj.TrySetValue(value);
-        }
+        public static void SetString(this TiffFrameMetadata meta, ExifTag tag, string value) =>
+            meta.FrameTags.SetValueInternal(tag, value);
 
         public static TEnum? GetSingleEnumNullable<TEnum, TTagValue>(this TiffFrameMetadata meta, ExifTag tag)
           where TEnum : struct
@@ -105,15 +100,10 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
             where TTagValue : struct
         => meta.GetSingleEnumNullable<TEnum, TTagValue>(tag) ?? (defaultValue != null ? defaultValue.Value : throw TiffThrowHelper.TagNotFound(nameof(tag)));
 
-        public static bool SetSingleEnum<TEnum, TTagValue>(this TiffFrameMetadata meta, ExifTag tag, TEnum value)
+        public static void SetSingleEnum<TEnum, TTagValue>(this TiffFrameMetadata meta, ExifTag tag, TEnum value)
         where TEnum : struct
         where TTagValue : struct
-        {
-            IExifValue obj = FindOrCreate(meta, tag);
-
-            object val = (TTagValue)(object)value;
-            return obj.TrySetValue(val);
-        }
+            => meta.FrameTags.SetValueInternal(tag, value);
 
         public static T GetSingle<T>(this TiffFrameMetadata meta, ExifTag tag)
             where T : struct
@@ -129,7 +119,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
         public static bool TryGetSingle<T>(this TiffFrameMetadata meta, ExifTag tag, out T result)
             where T : struct
         {
-            foreach (IExifValue entry in meta.FrameTags)
+            foreach (IExifValue entry in meta.FrameTags.Values)
             {
                 if (entry.Tag == tag)
                 {
@@ -146,20 +136,14 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
             return false;
         }
 
-        public static bool SetSingle<T>(this TiffFrameMetadata meta, ExifTag tag, T value)
+        public static void SetSingle<T>(this TiffFrameMetadata meta, ExifTag tag, T value)
             where T : struct
-        {
-            IExifValue obj = FindOrCreate(meta, tag);
-            DebugGuard.IsTrue(!obj.IsArray, "Expected non array entry");
-
-            object val = value;
-            return obj.TrySetValue(val);
-        }
+            => meta.FrameTags.SetValueInternal(tag, value);
 
         public static bool Remove(this TiffFrameMetadata meta, ExifTag tag)
         {
             IExifValue obj = null;
-            foreach (IExifValue entry in meta.FrameTags)
+            foreach (IExifValue entry in meta.FrameTags.Values)
             {
                 if (entry.Tag == tag)
                 {
@@ -170,31 +154,10 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
 
             if (obj != null)
             {
-                return meta.FrameTags.Remove(obj);
+                return meta.FrameTags.RemoveValue(obj.Tag);
             }
 
             return false;
         }
-
-        private static IExifValue FindOrCreate(TiffFrameMetadata meta, ExifTag tag)
-        {
-            IExifValue obj = null;
-            foreach (IExifValue entry in meta.FrameTags)
-            {
-                if (entry.Tag == tag)
-                {
-                    obj = entry;
-                    break;
-                }
-            }
-
-            if (obj == null)
-            {
-                obj = ExifValues.Create(tag);
-                meta.FrameTags.Add(obj);
-            }
-
-            return obj;
-        }
     }
 }

src/ImageSharp/Metadata/Profiles/Exif/ExifProfile.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+
 using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp.Metadata.Profiles.Exif
@@ -258,6 +259,9 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Exif
             this.SyncResolution(ExifTag.YResolution, metadata.VerticalResolution);
         }
 
+        internal void InitializeInternal(List<IExifValue> values) =>
+            this.values = values;
+
         private void SyncResolution(ExifTag<Rational> tag, double resolution)
         {
             IExifValue<Rational> value = this.GetValue(tag);