Prevent memory allocations

src/ImageSharp/Formats/Gif/GifEncoderCore.cs

@@ -339,7 +339,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
             // Application Extension: XMP Profile.
             if (xmpProfile != null)
             {
-                var xmpExtension = new GifXmpApplicationExtension(xmpProfile.ToByteArray());
+                var xmpExtension = new GifXmpApplicationExtension(xmpProfile.Data);
                 this.WriteExtension(xmpExtension, stream);
             }
         }

src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs

@@ -681,9 +681,9 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         /// <param name="remaining">The remaining bytes in the segment block.</param>
         private void ProcessApp1Marker(BufferedReadStream stream, int remaining)
         {
-            const int Exif00 = 6;
-            const int XmpNsLength = 29;
-            if (remaining < Exif00 || this.IgnoreMetadata)
+            const int ExifMarkerLength = 6;
+            const int XmpMarkerLength = 29;
+            if (remaining < ExifMarkerLength || this.IgnoreMetadata)
             {
                 // Skip the application header length
                 stream.Skip(remaining);
@@ -695,38 +695,55 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
                 JpegThrowHelper.ThrowInvalidImageContentException("Bad App1 Marker length.");
             }
 
-            byte[] profile = new byte[remaining];
-            stream.Read(profile, 0, remaining);
+            // XMP marker is the longest, so read at least that many bytes into temp.
+            stream.Read(this.temp, 0, ExifMarkerLength);
 
-            if (ProfileResolver.IsProfile(profile, ProfileResolver.ExifMarker))
+            if (ProfileResolver.IsProfile(this.temp, ProfileResolver.ExifMarker))
             {
+                remaining -= ExifMarkerLength;
                 this.isExif = true;
+                byte[] profile = new byte[remaining];
+                stream.Read(profile, 0, remaining);
+
                 if (this.exifData is null)
                 {
-                    // The first 6 bytes (Exif00) will be skipped, because this is Jpeg specific
-                    this.exifData = profile.AsSpan(Exif00).ToArray();
+                    this.exifData = profile;
                 }
                 else
                 {
                     // If the EXIF information exceeds 64K, it will be split over multiple APP1 markers
-                    this.ExtendProfile(ref this.exifData, profile.AsSpan(Exif00).ToArray());
+                    this.ExtendProfile(ref this.exifData, profile);
                 }
+
+                remaining = 0;
             }
 
-            if (ProfileResolver.IsProfile(profile, ProfileResolver.XmpMarker))
+            if (ProfileResolver.IsProfile(this.temp, ProfileResolver.XmpMarker.Slice(0, ExifMarkerLength)))
             {
-                this.isXmp = true;
-                if (this.xmpData is null)
+                stream.Read(this.temp, 0, XmpMarkerLength - ExifMarkerLength);
+                remaining -= XmpMarkerLength;
+                if (ProfileResolver.IsProfile(this.temp, ProfileResolver.XmpMarker.Slice(ExifMarkerLength)))
                 {
-                    // The first 29 bytes will be skipped, because this is Jpeg specific
-                    this.xmpData = profile.AsSpan(XmpNsLength).ToArray();
-                }
-                else
-                {
-                    // If the XMP information exceeds 64K, it will be split over multiple APP1 markers
-                    this.ExtendProfile(ref this.xmpData, profile.AsSpan(XmpNsLength).ToArray());
+                    this.isXmp = true;
+                    byte[] profile = new byte[remaining];
+                    stream.Read(profile, 0, remaining);
+
+                    if (this.xmpData is null)
+                    {
+                        this.xmpData = profile;
+                    }
+                    else
+                    {
+                        // If the XMP information exceeds 64K, it will be split over multiple APP1 markers
+                        this.ExtendProfile(ref this.xmpData, profile);
+                    }
+
+                    remaining = 0;
                 }
             }
+
+            // Skip over any remaining bytes of this header.
+            stream.Skip(remaining);
         }
 
         /// <summary>

src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs

@@ -485,7 +485,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
             const int Max = 65533;
             const int MaxData = Max - XmpOverheadLength;
 
-            byte[] data = xmpProfile.ToByteArray();
+            byte[] data = xmpProfile.Data;
 
             if (data is null || data.Length == 0)
             {

src/ImageSharp/Formats/Png/PngEncoderCore.cs

@@ -673,7 +673,7 @@ namespace SixLabors.ImageSharp.Formats.Png
                 return;
             }
 
-            var xmpData = meta.XmpProfile.ToByteArray();
+            var xmpData = meta.XmpProfile.Data;
 
             if (xmpData.Length == 0)
             {

src/ImageSharp/Formats/Tiff/TiffEncoderEntriesCollector.cs

@@ -204,7 +204,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff
                 {
                     var xmp = new ExifByteArray(ExifTagValue.XMP, ExifDataType.Byte)
                     {
-                        Value = xmpProfile.ToByteArray()
+                        Value = xmpProfile.Data
                     };
 
                     this.Collector.Add(xmp);

src/ImageSharp/Formats/Webp/BitWriter/Vp8BitWriter.cs

@@ -427,7 +427,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.BitWriter
             {
                 isVp8X = true;
                 riffSize += ExtendedFileChunkSize;
-                xmpBytes = xmpProfile.ToByteArray();
+                xmpBytes = xmpProfile.Data;
                 riffSize += this.MetadataChunkSize(xmpBytes);
             }
 

src/ImageSharp/Formats/Webp/BitWriter/Vp8LBitWriter.cs

@@ -155,7 +155,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.BitWriter
             {
                 isVp8X = true;
                 riffSize += ExtendedFileChunkSize;
-                xmpBytes = xmpProfile.ToByteArray();
+                xmpBytes = xmpProfile.Data;
                 riffSize += this.MetadataChunkSize(xmpBytes);
             }
 

src/ImageSharp/Metadata/Profiles/XMP/XmpProfile.cs

@@ -14,8 +14,6 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Xmp
     /// </summary>
     public sealed class XmpProfile : IDeepCloneable<XmpProfile>
     {
-        private byte[] data;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="XmpProfile"/> class.
         /// </summary>
@@ -28,7 +26,7 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Xmp
         /// Initializes a new instance of the <see cref="XmpProfile"/> class.
         /// </summary>
         /// <param name="data">The UTF8 encoded byte array to read the XMP profile from.</param>
-        public XmpProfile(byte[] data) => this.data = data;
+        public XmpProfile(byte[] data) => this.Data = data;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="XmpProfile"/> class
@@ -39,16 +37,21 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Xmp
         {
             Guard.NotNull(other, nameof(other));
 
-            this.data = other.ToByteArray();
+            this.Data = other.Data;
         }
 
+        /// <summary>
+        /// Gets the XMP raw data byte array.
+        /// </summary>
+        internal byte[] Data { get; private set; }
+
         /// <summary>
         /// Gets the raw XML document containing the XMP profile.
         /// </summary>
         /// <returns>The <see cref="XDocument"/></returns>
         public XDocument GetDocument()
         {
-            byte[] byteArray = this.ToByteArray();
+            byte[] byteArray = this.Data;
             if (byteArray is null)
             {
                 return null;
@@ -75,8 +78,8 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Xmp
         /// <returns>The <see cref="T:byte[]"/></returns>
         public byte[] ToByteArray()
         {
-            byte[] result = new byte[this.data.Length];
-            this.data.AsSpan().CopyTo(result);
+            byte[] result = new byte[this.Data.Length];
+            this.Data.AsSpan().CopyTo(result);
             return result;
         }
 

tests/ImageSharp.Tests/Formats/Tiff/TiffMetadataTests.cs

@@ -133,7 +133,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
                 {
                     Assert.NotNull(rootFrameMetaData.XmpProfile);
                     Assert.NotNull(rootFrameMetaData.ExifProfile);
-                    Assert.Equal(2599, rootFrameMetaData.XmpProfile.ToByteArray().Length);
+                    Assert.Equal(2599, rootFrameMetaData.XmpProfile.Data.Length);
                     Assert.Equal(26, rootFrameMetaData.ExifProfile.Values.Count);
                 }
             }
@@ -164,7 +164,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
                 Assert.Equal(32, rootFrame.Width);
                 Assert.Equal(32, rootFrame.Height);
                 Assert.NotNull(rootFrame.Metadata.XmpProfile);
-                Assert.Equal(2599, rootFrame.Metadata.XmpProfile.ToByteArray().Length);
+                Assert.Equal(2599, rootFrame.Metadata.XmpProfile.Data.Length);
 
                 ExifProfile exifProfile = rootFrame.Metadata.ExifProfile;
                 TiffFrameMetadata tiffFrameMetadata = rootFrame.Metadata.GetTiffMetadata();
@@ -291,7 +291,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
 
             Assert.NotNull(xmpProfileInput);
             Assert.NotNull(encodedImageXmpProfile);
-            Assert.Equal(xmpProfileInput.ToByteArray(), encodedImageXmpProfile.ToByteArray());
+            Assert.Equal(xmpProfileInput.Data, encodedImageXmpProfile.Data);
 
             Assert.Equal("IrfanView", exifProfileInput.GetValue(ExifTag.Software).Value);
             Assert.Equal("This is Название", exifProfileInput.GetValue(ExifTag.ImageDescription).Value);

tests/ImageSharp.Tests/Formats/WebP/WebpMetaDataTests.cs

@@ -79,7 +79,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Webp
             else
             {
                 Assert.NotNull(image.Metadata.XmpProfile);
-                Assert.NotEmpty(image.Metadata.XmpProfile.ToByteArray());
+                Assert.NotEmpty(image.Metadata.XmpProfile.Data);
             }
         }
 

tests/ImageSharp.Tests/Metadata/ImageFrameMetadataTests.cs

@@ -73,7 +73,7 @@ namespace SixLabors.ImageSharp.Tests.Metadata
             Assert.False(metaData.ExifProfile.Equals(clone.ExifProfile));
             Assert.True(metaData.ExifProfile.Values.Count == clone.ExifProfile.Values.Count);
             Assert.False(ReferenceEquals(metaData.XmpProfile, clone.XmpProfile));
-            Assert.True(metaData.XmpProfile.ToByteArray().Length.Equals(clone.XmpProfile.ToByteArray().Length));
+            Assert.True(metaData.XmpProfile.Data.Equals(clone.XmpProfile.Data));
             Assert.False(metaData.GetGifMetadata().Equals(clone.GetGifMetadata()));
             Assert.False(metaData.IccProfile.Equals(clone.IccProfile));
             Assert.False(metaData.IptcProfile.Equals(clone.IptcProfile));

tests/ImageSharp.Tests/Metadata/Profiles/XMP/XmpProfileTests.cs

@@ -135,7 +135,7 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.Xmp
             // assert
             XmpProfile actual = reloadedImage.Metadata.XmpProfile ?? reloadedImage.Frames.RootFrame.Metadata.XmpProfile;
             XmpProfileContainsExpectedValues(actual);
-            Assert.Equal(original.ToByteArray(), actual.ToByteArray());
+            Assert.Equal(original.Data, actual.Data);
         }
 
         [Fact]
@@ -153,7 +153,7 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.Xmp
             // assert
             XmpProfile actual = reloadedImage.Metadata.XmpProfile ?? reloadedImage.Frames.RootFrame.Metadata.XmpProfile;
             XmpProfileContainsExpectedValues(actual);
-            Assert.Equal(original.ToByteArray(), actual.ToByteArray());
+            Assert.Equal(original.Data, actual.Data);
         }
 
         [Fact]
@@ -171,7 +171,7 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.Xmp
             // assert
             XmpProfile actual = reloadedImage.Metadata.XmpProfile ?? reloadedImage.Frames.RootFrame.Metadata.XmpProfile;
             XmpProfileContainsExpectedValues(actual);
-            Assert.Equal(original.ToByteArray(), actual.ToByteArray());
+            Assert.Equal(original.Data, actual.Data);
         }
 
         [Fact]
@@ -189,7 +189,7 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.Xmp
             // assert
             XmpProfile actual = reloadedImage.Metadata.XmpProfile ?? reloadedImage.Frames.RootFrame.Metadata.XmpProfile;
             XmpProfileContainsExpectedValues(actual);
-            Assert.Equal(original.ToByteArray(), actual.ToByteArray());
+            Assert.Equal(original.Data, actual.Data);
         }
 
         [Fact]
@@ -207,7 +207,7 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.Xmp
             // assert
             XmpProfile actual = reloadedImage.Metadata.XmpProfile ?? reloadedImage.Frames.RootFrame.Metadata.XmpProfile;
             XmpProfileContainsExpectedValues(actual);
-            Assert.Equal(original.ToByteArray(), actual.ToByteArray());
+            Assert.Equal(original.Data, actual.Data);
         }
 
         [Fact]
@@ -225,7 +225,7 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.Xmp
             // assert
             XmpProfile actual = reloadedImage.Metadata.XmpProfile ?? reloadedImage.Frames.RootFrame.Metadata.XmpProfile;
             XmpProfileContainsExpectedValues(actual);
-            Assert.Equal(original.ToByteArray(), actual.ToByteArray());
+            Assert.Equal(original.Data, actual.Data);
         }
 
         private static void XmpProfileContainsExpectedValues(XmpProfile xmp)