Changed GetDimensions to handle a stream at the end and one exit

Metadata/Models/Stateless/Dimensions.cs

@@ -8,16 +8,16 @@ internal static class Dimensions
 #pragma warning disable IDE0230
     private static readonly Dictionary<byte[], Func<BinaryReader, Size?>> _ImageFormatDecoders = new()
     {
+        { new byte[] { 0xff, 0xd8 }, DecodeJfif },
         { new byte[] { 0x42, 0x4D }, DecodeBitmap },
+        { new byte[] { 0x52, 0x49, 0x46, 0x46 }, DecodeWebP },
         { new byte[] { 0x47, 0x49, 0x46, 0x38, 0x37, 0x61 }, DecodeGif },
         { new byte[] { 0x47, 0x49, 0x46, 0x38, 0x39, 0x61 }, DecodeGif },
         { new byte[] { 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A }, DecodePng },
-        { new byte[] { 0xff, 0xd8 }, DecodeJfif },
-        { new byte[] { 0x52, 0x49, 0x46, 0x46 }, DecodeWebP },
     };
 #pragma warning restore IDE0230
 
-    private static bool StartsWith(byte[] thisBytes, byte[] thatBytes)
+    private static bool StartsWith(List<byte> thisBytes, byte[] thatBytes)
     {
         for (int i = 0; i < thatBytes.Length; i += 1)
         {
@@ -103,24 +103,41 @@ internal static class Dimensions
 
     internal static Size? GetDimensions(BinaryReader binaryReader)
     {
-        int maxMagicBytesLength = _ImageFormatDecoders.Keys.OrderByDescending(x => x.Length).First().Length;
+        Size? result;
-        byte[] magicBytes = new byte[maxMagicBytesLength];
+        List<byte> magicBytes = [];
-        for (int i = 0; i < maxMagicBytesLength; i += 1)
+        int[] magicBytesLengths = (from l in _ImageFormatDecoders.Keys where l.Length <= binaryReader.BaseStream.Length orderby l.Length descending select l.Length).ToArray();
+        if (magicBytesLengths.Length == 0)
+            result = null;
+        else
         {
-            magicBytes[i] = binaryReader.ReadByte();
+            result = null;
-            foreach (KeyValuePair<byte[], Func<BinaryReader, Size?>> kvPair in _ImageFormatDecoders)
+            if (binaryReader.BaseStream.Length == binaryReader.BaseStream.Position)
+                _ = binaryReader.BaseStream.Seek(0, SeekOrigin.Begin);
+            for (int i = 0; i < magicBytesLengths[0]; i++)
             {
-                if (StartsWith(magicBytes, kvPair.Key))
+                magicBytes.Add(binaryReader.ReadByte());
-                    return kvPair.Value(binaryReader);
+                foreach (KeyValuePair<byte[], Func<BinaryReader, Size?>> kvPair in _ImageFormatDecoders)
+                {
+                    if (StartsWith(magicBytes, kvPair.Key))
+                    {
+                        result = kvPair.Value(binaryReader);
+                        break;
+                    }
+                }
+                if (result is not null)
+                    break;
             }
         }
-        return null;
+        return result;
     }
 
     internal static Size? GetDimensions(string path)
     {
-        using BinaryReader binaryReader = new(File.OpenRead(path));
+        Size? result;
-        return GetDimensions(binaryReader);
+        using FileStream fileStream = File.OpenRead(path);
+        using BinaryReader binaryReader = new(fileStream);
+        result = GetDimensions(binaryReader);
+        return result;
     }
 
 }

Shared/Models/FaceFileSystem.cs

@@ -76,7 +76,7 @@ public class FaceFileSystem : FileSystem, Properties.IFaceFileSystem
         }
         else
         {
-            System.Drawing.Size size = Stateless.Methods.ImageHelper.GetDimensions(fileInfo.FullName, faceRight, faceBottom);
+            System.Drawing.Size size = Stateless.Methods.Dimensions.GetDimensions(fileInfo.FullName, faceRight, faceBottom);
             imageWidth = size.Width;
             imageHeight = size.Height;
         }

Shared/Models/Stateless/Methods/Dimensions.cs

@@ -0,0 +1,149 @@
+using System.Drawing;
+
+namespace View_by_Distance.Shared.Models.Stateless.Methods;
+
+internal static class Dimensions
+{
+
+#pragma warning disable IDE0230
+    private static readonly Dictionary<byte[], Func<BinaryReader, Size?>> _ImageFormatDecoders = new()
+    {
+        { new byte[] { 0xff, 0xd8 }, DecodeJfif },
+        { new byte[] { 0x42, 0x4D }, DecodeBitmap },
+        { new byte[] { 0x52, 0x49, 0x46, 0x46 }, DecodeWebP },
+        { new byte[] { 0x47, 0x49, 0x46, 0x38, 0x37, 0x61 }, DecodeGif },
+        { new byte[] { 0x47, 0x49, 0x46, 0x38, 0x39, 0x61 }, DecodeGif },
+        { new byte[] { 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A }, DecodePng },
+    };
+#pragma warning restore IDE0230
+
+    private static bool StartsWith(List<byte> thisBytes, byte[] thatBytes)
+    {
+        for (int i = 0; i < thatBytes.Length; i += 1)
+        {
+            if (thisBytes[i] == thatBytes[i])
+                continue;
+            return false;
+        }
+        return true;
+    }
+
+    private static short ReadLittleEndianInt16(BinaryReader binaryReader)
+    {
+        byte[] bytes = new byte[sizeof(short)];
+        for (int i = 0; i < sizeof(short); i += 1)
+            bytes[sizeof(short) - 1 - i] = binaryReader.ReadByte();
+        return BitConverter.ToInt16(bytes, 0);
+    }
+
+    private static int ReadLittleEndianInt32(BinaryReader binaryReader)
+    {
+        byte[] bytes = new byte[sizeof(int)];
+        for (int i = 0; i < sizeof(int); i += 1)
+            bytes[sizeof(int) - 1 - i] = binaryReader.ReadByte();
+        return BitConverter.ToInt32(bytes, 0);
+    }
+
+    private static Size? DecodeBitmap(BinaryReader binaryReader)
+    {
+        _ = binaryReader.ReadBytes(16);
+        int width = binaryReader.ReadInt32();
+        int height = binaryReader.ReadInt32();
+        return new Size(width, height);
+    }
+
+    private static Size? DecodeGif(BinaryReader binaryReader)
+    {
+        int width = binaryReader.ReadInt16();
+        int height = binaryReader.ReadInt16();
+        return new Size(width, height);
+    }
+
+    private static Size? DecodePng(BinaryReader binaryReader)
+    {
+        _ = binaryReader.ReadBytes(8);
+        int width = ReadLittleEndianInt32(binaryReader);
+        int height = ReadLittleEndianInt32(binaryReader);
+        return new Size(width, height);
+    }
+
+    private static Size? DecodeJfif(BinaryReader binaryReader)
+    {
+        while (binaryReader.ReadByte() == 0xff)
+        {
+            byte marker = binaryReader.ReadByte();
+            short chunkLength = ReadLittleEndianInt16(binaryReader);
+            if (marker == 0xc0)
+            {
+                _ = binaryReader.ReadByte();
+                int height = ReadLittleEndianInt16(binaryReader);
+                int width = ReadLittleEndianInt16(binaryReader);
+                return new Size(width, height);
+            }
+            if (chunkLength >= 0)
+                _ = binaryReader.ReadBytes(chunkLength - 2);
+            else
+            {
+                ushort uChunkLength = (ushort)chunkLength;
+                _ = binaryReader.ReadBytes(uChunkLength - 2);
+            }
+        }
+        return null;
+    }
+
+    private static Size? DecodeWebP(BinaryReader binaryReader)
+    {
+        _ = binaryReader.ReadUInt32(); // Size
+        _ = binaryReader.ReadBytes(15); // WEBP, VP8 + more
+        _ = binaryReader.ReadBytes(3); // SYNC
+        int width = binaryReader.ReadUInt16() & 0b00_11111111111111; // 14 bits width
+        int height = binaryReader.ReadUInt16() & 0b00_11111111111111; // 14 bits height
+        return new Size(width, height);
+    }
+
+    internal static Size GetDimensions(BinaryReader binaryReader, int? faceRight, int? faceBottom)
+    {
+        Size? result;
+        List<byte> magicBytes = [];
+        int[] magicBytesLengths = (from l in _ImageFormatDecoders.Keys where l.Length <= binaryReader.BaseStream.Length orderby l.Length descending select l.Length).ToArray();
+        if (magicBytesLengths.Length == 0)
+            result = null;
+        else
+        {
+            result = null;
+            if (binaryReader.BaseStream.Length == binaryReader.BaseStream.Position)
+                _ = binaryReader.BaseStream.Seek(0, SeekOrigin.Begin);
+            for (int i = 0; i < magicBytesLengths[0]; i++)
+            {
+                magicBytes.Add(binaryReader.ReadByte());
+                foreach (KeyValuePair<byte[], Func<BinaryReader, Size?>> kvPair in _ImageFormatDecoders)
+                {
+                    if (StartsWith(magicBytes, kvPair.Key))
+                    {
+                        result = kvPair.Value(binaryReader);
+                        break;
+                    }
+                }
+                if (result is not null)
+                    break;
+            }
+        }        
+        if (result is null)
+        {
+            if (faceRight is null || faceBottom is null)
+                throw new Exception("face is null!");
+            result = new(faceRight.Value, faceBottom.Value);
+        }
+        return result.Value;
+    }
+
+    internal static Size GetDimensions(string path, int? faceRight, int? faceBottom)
+    {
+        Size result;
+        using FileStream fileStream = File.OpenRead(path);
+        using BinaryReader binaryReader = new(fileStream);
+        result = GetDimensions(binaryReader, faceRight, faceBottom);
+        return result;
+    }
+
+}

Shared/Models/Stateless/Methods/ImageHelper.cs

@@ -1,132 +0,0 @@
-using System.Drawing;
-
-namespace View_by_Distance.Shared.Models.Stateless.Methods;
-
-internal abstract class ImageHelper
-{
-
-    private static bool StartsWith(byte[] thisBytes, byte[] thatBytes)
-    {
-        for (int i = 0; i < thatBytes.Length; i += 1)
-        {
-            if (thisBytes[i] != thatBytes[i])
-                return false;
-        }
-        return true;
-    }
-
-    private static short ReadLittleEndianInt16(BinaryReader binaryReader)
-    {
-        byte[] bytes = new byte[sizeof(short)];
-        for (int i = 0; i < sizeof(short); i += 1)
-            bytes[sizeof(short) - 1 - i] = binaryReader.ReadByte();
-        return BitConverter.ToInt16(bytes, 0);
-    }
-
-    private static int ReadLittleEndianInt32(BinaryReader binaryReader)
-    {
-        byte[] bytes = new byte[sizeof(int)];
-        for (int i = 0; i < sizeof(int); i += 1)
-            bytes[sizeof(int) - 1 - i] = binaryReader.ReadByte();
-        return BitConverter.ToInt32(bytes, 0);
-    }
-
-    private static Size DecodeBitmap(BinaryReader binaryReader)
-    {
-        _ = binaryReader.ReadBytes(16);
-        int width = binaryReader.ReadInt32();
-        int height = binaryReader.ReadInt32();
-        return new Size(width, height);
-    }
-
-    private static Size DecodeGif(BinaryReader binaryReader)
-    {
-        int width = binaryReader.ReadInt16();
-        int height = binaryReader.ReadInt16();
-        return new Size(width, height);
-    }
-
-    private static Size DecodePng(BinaryReader binaryReader)
-    {
-        _ = binaryReader.ReadBytes(8);
-        int width = ReadLittleEndianInt32(binaryReader);
-        int height = ReadLittleEndianInt32(binaryReader);
-        return new Size(width, height);
-    }
-
-    private static Size DecodeJfif(BinaryReader binaryReader)
-    {
-        while (binaryReader.ReadByte() == 0xff)
-        {
-            byte marker = binaryReader.ReadByte();
-            short chunkLength = ReadLittleEndianInt16(binaryReader);
-            if (marker == 0xc0)
-            {
-                _ = binaryReader.ReadByte();
-                int height = ReadLittleEndianInt16(binaryReader);
-                int width = ReadLittleEndianInt16(binaryReader);
-                return new Size(width, height);
-            }
-            _ = binaryReader.ReadBytes(chunkLength - 2);
-        }
-        throw new ArgumentException("Could not recognize image format.");
-    }
-
-    /// <summary>
-    /// Gets the dimensions of an image.
-    /// </summary>
-    /// <param name="path">The path of the image to get the dimensions of.</param>
-    /// <returns>The dimensions of the specified image.</returns>
-    /// <exception cref="ArgumentException">The image was of an unrecognized format.</exception>    
-    internal static Size GetDimensions(BinaryReader binaryReader, int? faceRight, int? faceBottom)
-    {
-        Size? result = null;
-#pragma warning disable IDE0230
-        Dictionary<byte[], Func<BinaryReader, Size>> _ImageFormatDecoders = new()
-        {
-            { new byte[] { 0x42, 0x4D }, DecodeBitmap },
-            { new byte[] { 0x47, 0x49, 0x46, 0x38, 0x37, 0x61 }, DecodeGif },
-            { new byte[] { 0x47, 0x49, 0x46, 0x38, 0x39, 0x61 }, DecodeGif },
-            { new byte[] { 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A }, DecodePng },
-            { new byte[] { 0xff, 0xd8 }, DecodeJfif },
-        };
-#pragma warning restore IDE0230
-        int maxMagicBytesLength = _ImageFormatDecoders.Keys.OrderByDescending(x => x.Length).First().Length;
-        byte[] magicBytes = new byte[maxMagicBytesLength];
-        for (int i = 0; i < maxMagicBytesLength; i += 1)
-        {
-            magicBytes[i] = binaryReader.ReadByte();
-            foreach (KeyValuePair<byte[], Func<BinaryReader, Size>> kvPair in _ImageFormatDecoders)
-            {
-                if (!StartsWith(magicBytes, kvPair.Key))
-                    continue;
-                result = kvPair.Value(binaryReader);
-                break;
-            }
-            if (result is not null)
-                break;
-        }
-        if (result is null)
-        {
-            if (faceRight is null || faceBottom is null)
-                throw new Exception("face is null!");
-            result = new(faceRight.Value, faceBottom.Value);
-        }
-        return result.Value;
-    }
-
-    /// <summary>
-    /// Gets the dimensions of an image.
-    /// </summary>
-    /// <param name="path">The path of the image to get the dimensions of.</param>
-    /// <returns>The dimensions of the specified image.</returns>
-    /// <exception cref="ArgumentException">The image was of an unrecognized format.</exception>
-    internal static Size GetDimensions(string path, int? faceRight, int? faceBottom)
-    {
-        Size result;
-        using BinaryReader binaryReader = new(File.OpenRead(path));
-        result = GetDimensions(binaryReader, faceRight, faceBottom);
-        return result;
-    }
-
-}