Merge pull request #404 from drewnoakes/pool-indexed-capturing-reader-chunks

Pool buffers in IndexedCapturingReader

Author: drewnoakes

MetadataExtractor/Formats/Png/PngMetadataReader.cs

@@ -170,7 +170,8 @@ private static IEnumerable<Directory> ProcessChunk(PngChunk chunk)
                     try
                     {
                         using var inflaterStream = new DeflateStream(new MemoryStream(compressedProfile), CompressionMode.Decompress);
-                        iccDirectory = new IccReader().Extract(new IndexedCapturingReader(inflaterStream));
+                        using var iccReader = new IndexedCapturingReader(inflaterStream);
+                        iccDirectory = new IccReader().Extract(iccReader);
                         iccDirectory.Parent = directory;
                     }
                     catch (Exception e)

MetadataExtractor/Formats/Tiff/TiffMetadataReader.cs

@@ -41,7 +41,9 @@ public static IReadOnlyList<Directory> ReadMetadata(Stream stream)
             var directories = new List<Directory>();
 
             var handler = new ExifTiffHandler(directories, exifStartOffset: 0);
-            TiffReader.ProcessTiff(new IndexedCapturingReader(stream), handler);
+
+            using var reader = new IndexedCapturingReader(stream);
+            TiffReader.ProcessTiff(reader, handler);
 
             return directories;
         }

MetadataExtractor/IO/IndexedCapturingReader.cs

@@ -1,9 +1,11 @@
 // Copyright (c) Drew Noakes and contributors. All Rights Reserved. Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
 
+using System.Buffers;
+
 namespace MetadataExtractor.IO
 {
     /// <author>Drew Noakes https://drewnoakes.com</author>
-    public sealed class IndexedCapturingReader : IndexedReader
+    public sealed class IndexedCapturingReader : IndexedReader, IDisposable
     {
         private const int DefaultChunkLength = 2 * 1024;
 
@@ -99,7 +101,7 @@ private bool IsValidIndex(int index, int bytesRequested)
             {
                 Debug.Assert(!_isStreamFinished);
 
-                var chunk = new byte[_chunkLength];
+                var chunk = ArrayPool<byte>.Shared.Rent(_chunkLength);
                 var totalBytesRead = 0;
                 while (!_isStreamFinished && totalBytesRead != _chunkLength)
                 {
@@ -129,6 +131,14 @@ private bool IsValidIndex(int index, int bytesRequested)
             return true;
         }
 
+        public void Dispose()
+        {
+            foreach (var chunk in _chunks)
+            {
+                ArrayPool<byte>.Shared.Return(chunk);
+            }
+        }
+
         public override int ToUnshiftedOffset(int localOffset) => localOffset;
 
         private void GetPosition(int index, out int chunkIndex, out int innerIndex)

MetadataExtractor/PublicAPI/net462/PublicAPI.Unshipped.txt

@@ -111,6 +111,7 @@ MetadataExtractor.Formats.Png.PngDirectory.GetPngChunkType() -> MetadataExtracto
 MetadataExtractor.Formats.Png.PngDirectory.PngDirectory(MetadataExtractor.Formats.Png.PngChunkType pngChunkType) -> void
 MetadataExtractor.GeoLocation.Equals(MetadataExtractor.GeoLocation other) -> bool
 MetadataExtractor.GeoLocation.GeoLocation() -> void
+MetadataExtractor.IO.IndexedCapturingReader.Dispose() -> void
 MetadataExtractor.IO.IndexedReader.GetByte(int index) -> byte
 MetadataExtractor.IO.IndexedReader.GetBytes(int index, int count) -> byte[]!
 MetadataExtractor.Util.FileType.Avif = 28 -> MetadataExtractor.Util.FileType

MetadataExtractor/PublicAPI/net8.0/PublicAPI.Unshipped.txt

@@ -110,6 +110,7 @@ MetadataExtractor.Formats.Png.PngDirectory.GetPngChunkType() -> MetadataExtracto
 MetadataExtractor.Formats.Png.PngDirectory.PngDirectory(MetadataExtractor.Formats.Png.PngChunkType pngChunkType) -> void
 MetadataExtractor.GeoLocation.Equals(MetadataExtractor.GeoLocation other) -> bool
 MetadataExtractor.GeoLocation.GeoLocation() -> void
+MetadataExtractor.IO.IndexedCapturingReader.Dispose() -> void
 MetadataExtractor.IO.IndexedReader.GetByte(int index) -> byte
 MetadataExtractor.IO.IndexedReader.GetBytes(int index, int count) -> byte[]!
 MetadataExtractor.Util.FileType.Avif = 28 -> MetadataExtractor.Util.FileType

MetadataExtractor/PublicAPI/netstandard1.3/PublicAPI.Unshipped.txt

@@ -111,6 +111,7 @@ MetadataExtractor.Formats.Png.PngDirectory.GetPngChunkType() -> MetadataExtracto
 MetadataExtractor.Formats.Png.PngDirectory.PngDirectory(MetadataExtractor.Formats.Png.PngChunkType pngChunkType) -> void
 MetadataExtractor.GeoLocation.Equals(MetadataExtractor.GeoLocation other) -> bool
 MetadataExtractor.GeoLocation.GeoLocation() -> void
+MetadataExtractor.IO.IndexedCapturingReader.Dispose() -> void
 MetadataExtractor.IO.IndexedReader.GetByte(int index) -> byte
 MetadataExtractor.IO.IndexedReader.GetBytes(int index, int count) -> byte[]!
 MetadataExtractor.Util.FileType.Avif = 28 -> MetadataExtractor.Util.FileType

MetadataExtractor/PublicAPI/netstandard2.1/PublicAPI.Unshipped.txt

@@ -110,6 +110,7 @@ MetadataExtractor.Formats.Png.PngDirectory.GetPngChunkType() -> MetadataExtracto
 MetadataExtractor.Formats.Png.PngDirectory.PngDirectory(MetadataExtractor.Formats.Png.PngChunkType pngChunkType) -> void
 MetadataExtractor.GeoLocation.Equals(MetadataExtractor.GeoLocation other) -> bool
 MetadataExtractor.GeoLocation.GeoLocation() -> void
+MetadataExtractor.IO.IndexedCapturingReader.Dispose() -> void
 MetadataExtractor.IO.IndexedReader.GetByte(int index) -> byte
 MetadataExtractor.IO.IndexedReader.GetBytes(int index, int count) -> byte[]!
 MetadataExtractor.Util.FileType.Avif = 28 -> MetadataExtractor.Util.FileType