diff --git a/src/ImageSharp/Formats/Png/PngDecoderCore.cs b/src/ImageSharp/Formats/Png/PngDecoderCore.cs index 0745a5f5a..470a245b2 100644 --- a/src/ImageSharp/Formats/Png/PngDecoderCore.cs +++ b/src/ImageSharp/Formats/Png/PngDecoderCore.cs @@ -1206,27 +1206,45 @@ namespace SixLabors.ImageSharp.Formats.Png ReadOnlySpan compressedData = data.Slice(zeroIndex + 2); - using (var memoryStream = new MemoryStream(compressedData.ToArray())) - using (var bufferedStream = new BufferedReadStream(this.Configuration, memoryStream)) - using (var inflateStream = new ZlibInflateStream(bufferedStream)) + if (this.TryUncompressZlibData(compressedData, out byte[] iccpProfileBytes)) { - if (!inflateStream.AllocateNewBytes(compressedData.Length, false)) + metadata.IccProfile = new IccProfile(iccpProfileBytes); + } + } + + /// + /// Tries to un-compress zlib compressed data. + /// + /// The compressed data. + /// The uncompressed bytes array. + /// True, if de-compressing was successful. + private unsafe bool TryUncompressZlibData(ReadOnlySpan compressedData, out byte[] uncompressedBytesArray) + { + fixed (byte* compressedDataBase = compressedData) + { + using (var memoryStream = new UnmanagedMemoryStream(compressedDataBase, compressedData.Length)) + using (var bufferedStream = new BufferedReadStream(this.Configuration, memoryStream)) + using (var inflateStream = new ZlibInflateStream(bufferedStream)) { - return; - } + if (!inflateStream.AllocateNewBytes(compressedData.Length, false)) + { + uncompressedBytesArray = Array.Empty(); + return false; + } - var uncompressedBytes = new List(); + var uncompressedBytes = new List(compressedData.Length); - // Note: this uses a buffer which is only 4 bytes long to read the stream, maybe allocating a larger buffer makes sense here. - int bytesRead = inflateStream.CompressedStream.Read(this.buffer, 0, this.buffer.Length); - while (bytesRead != 0) - { - uncompressedBytes.AddRange(this.buffer.AsSpan(0, bytesRead).ToArray()); - bytesRead = inflateStream.CompressedStream.Read(this.buffer, 0, this.buffer.Length); - } + // Note: this uses a buffer which is only 4 bytes long to read the stream, maybe allocating a larger buffer makes sense here. + int bytesRead = inflateStream.CompressedStream.Read(this.buffer, 0, this.buffer.Length); + while (bytesRead != 0) + { + uncompressedBytes.AddRange(this.buffer.AsSpan(0, bytesRead).ToArray()); + bytesRead = inflateStream.CompressedStream.Read(this.buffer, 0, this.buffer.Length); + } - byte[] iccpProfileBytes = uncompressedBytes.ToArray(); - metadata.IccProfile = new IccProfile(iccpProfileBytes); + uncompressedBytesArray = uncompressedBytes.ToArray(); + return true; + } } } @@ -1362,7 +1380,7 @@ namespace SixLabors.ImageSharp.Formats.Png } else if (this.IsXmpTextData(keywordBytes)) { - XmpProfile xmpProfile = new XmpProfile(data.Slice(dataStartIdx).ToArray()); + var xmpProfile = new XmpProfile(data.Slice(dataStartIdx).ToArray()); metadata.XmpProfile = xmpProfile; } else @@ -1381,29 +1399,14 @@ namespace SixLabors.ImageSharp.Formats.Png /// The . private bool TryUncompressTextData(ReadOnlySpan compressedData, Encoding encoding, out string value) { - using (var memoryStream = new MemoryStream(compressedData.ToArray())) - using (var bufferedStream = new BufferedReadStream(this.Configuration, memoryStream)) - using (var inflateStream = new ZlibInflateStream(bufferedStream)) + if (this.TryUncompressZlibData(compressedData, out byte[] uncompressedData)) { - if (!inflateStream.AllocateNewBytes(compressedData.Length, false)) - { - value = null; - return false; - } - - var uncompressedBytes = new List(); - - // Note: this uses a buffer which is only 4 bytes long to read the stream, maybe allocating a larger buffer makes sense here. - int bytesRead = inflateStream.CompressedStream.Read(this.buffer, 0, this.buffer.Length); - while (bytesRead != 0) - { - uncompressedBytes.AddRange(this.buffer.AsSpan(0, bytesRead).ToArray()); - bytesRead = inflateStream.CompressedStream.Read(this.buffer, 0, this.buffer.Length); - } - - value = encoding.GetString(uncompressedBytes.ToArray()); + value = encoding.GetString(uncompressedData); return true; } + + value = null; + return false; } ///