Move undoing zip compression into base class

src/ImageSharp/Formats/Exr/Compression/Decompressors/Pxr24Compression.cs

@@ -51,33 +51,8 @@ internal class Pxr24Compression : ExrBaseDecompressor
         Span<uint> outputBufferFloat = MemoryMarshal.Cast<byte, uint>(buffer);
         Span<uint> outputBufferUint = MemoryMarshal.Cast<byte, uint>(buffer);
 
-        long pos = stream.Position;
-        using ZlibInflateStream inflateStream = new(
-                   stream,
-                   () =>
-                   {
-                       int left = (int)(compressedBytes - (stream.Position - pos));
-                       return left > 0 ? left : 0;
-                   });
-        inflateStream.AllocateNewBytes((int)this.BytesPerBlock, true);
-        using DeflateStream dataStream = inflateStream.CompressedStream!;
-
-        int totalRead = 0;
-        while (totalRead < buffer.Length)
-        {
-            int bytesRead = dataStream.Read(uncompressed, totalRead, buffer.Length - totalRead);
-            if (bytesRead <= 0)
-            {
-                break;
-            }
-
-            totalRead += bytesRead;
-        }
-
-        if (totalRead == 0)
-        {
-            ExrThrowHelper.ThrowInvalidImageContentException("Could not read enough data for zip compressed image data!");
-        }
+        uint uncompressedBytes = this.BytesPerBlock;
+        UndoZipCompression(stream, compressedBytes, uncompressed, uncompressedBytes);
 
         int lastIn = 0;
         int outputOffset = 0;

src/ImageSharp/Formats/Exr/Compression/Decompressors/ZipExrCompression.cs

@@ -31,33 +31,8 @@ internal class ZipExrCompression : ExrBaseDecompressor
     {
         Span<byte> uncompressed = this.tmpBuffer.GetSpan();
 
-        long pos = stream.Position;
-        using ZlibInflateStream inflateStream = new(
-                   stream,
-                   () =>
-                   {
-                       int left = (int)(compressedBytes - (stream.Position - pos));
-                       return left > 0 ? left : 0;
-                   });
-        inflateStream.AllocateNewBytes((int)this.BytesPerBlock, true);
-        using DeflateStream dataStream = inflateStream.CompressedStream!;
-
-        int totalRead = 0;
-        while (totalRead < buffer.Length)
-        {
-            int bytesRead = dataStream.Read(uncompressed, totalRead, buffer.Length - totalRead);
-            if (bytesRead <= 0)
-            {
-                break;
-            }
-
-            totalRead += bytesRead;
-        }
-
-        if (totalRead == 0)
-        {
-            ExrThrowHelper.ThrowInvalidImageContentException("Could not read enough data for zip compressed image data!");
-        }
+        uint uncompressedBytes = (uint)buffer.Length;
+        int totalRead = UndoZipCompression(stream, compressedBytes, uncompressed, uncompressedBytes);
 
         Reconstruct(uncompressed, (uint)totalRead);
         Interleave(uncompressed, (uint)totalRead, buffer);

src/ImageSharp/Formats/Exr/Compression/ExrBaseDecompressor.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.IO.Compression;
+using SixLabors.ImageSharp.Compression.Zlib;
 using SixLabors.ImageSharp.IO;
 using SixLabors.ImageSharp.Memory;
 
@@ -31,6 +33,47 @@ internal abstract class ExrBaseDecompressor : ExrBaseCompression
     /// <param name="buffer">The buffer to write the decompressed data to.</param>
     public abstract void Decompress(BufferedReadStream stream, uint compressedBytes, Span<byte> buffer);
 
+    /// <summary>
+    /// Decompresses zip compressed data.
+    /// </summary>
+    /// <param name="stream">The buffered stream to decompress.</param>
+    /// <param name="compressedBytes">The compressed bytes.</param>
+    /// <param name="uncompressed">The buffer to write the uncompressed data to.</param>
+    /// <param name="uncompressedBytes">The uncompressed bytes.</param>
+    /// <returns>The total bytes read from the stream.</returns>
+    protected static int UndoZipCompression(BufferedReadStream stream, uint compressedBytes, Span<byte> uncompressed, uint uncompressedBytes)
+    {
+        long pos = stream.Position;
+        using ZlibInflateStream inflateStream = new(
+                   stream,
+                   () =>
+                   {
+                       int left = (int)(compressedBytes - (stream.Position - pos));
+                       return left > 0 ? left : 0;
+                   });
+        inflateStream.AllocateNewBytes((int)uncompressedBytes, true);
+        using DeflateStream dataStream = inflateStream.CompressedStream!;
+
+        int totalRead = 0;
+        while (totalRead < uncompressedBytes)
+        {
+            int bytesRead = dataStream.Read(uncompressed, totalRead, (int)uncompressedBytes - totalRead);
+            if (bytesRead <= 0)
+            {
+                break;
+            }
+
+            totalRead += bytesRead;
+        }
+
+        if (totalRead == 0)
+        {
+            ExrThrowHelper.ThrowInvalidImageContentException("Could not read enough data for zip compressed image data!");
+        }
+
+        return totalRead;
+    }
+
     /// <summary>
     /// Integrate over all differences to the previous value in order to
     /// reconstruct sample values.