Qfyilyi

I'm trying to parse a binary file as fastest as possible. So this is what I first tried to do:

using (FileStream filestream = path.OpenRead()) {

   using (var d = new GZipStream(filestream, CompressionMode.Decompress)) {

      using (MemoryStream m = new MemoryStream()) {

         d.CopyTo(m);

         m.Position = 0;



         using (BinaryReaderBigEndian b = new BinaryReaderBigEndian(m)) {

            while (b.BaseStream.Position != b.BaseStream.Length) {

               UInt32 value = b.ReadUInt32();

}  }  }  }  }

Where BinaryReaderBigEndian class is implemented as it follows:

public static class BinaryReaderBigEndian {

   public BinaryReaderBigEndian(Stream stream) : base(stream) { }



   public override UInt32 ReadUInt32() {

      var x = base.ReadBytes(4);

      Array.Reverse(x);

      return BitConverter.ToUInt32(x, 0);

}  }

Then, I tried to get a performance improvement using ReadOnlySpan instead of MemoryStream. So, I tried doing:

using (FileStream filestream = path.OpenRead()) {

   using (var d = new GZipStream(filestream, CompressionMode.Decompress)) {

      using (MemoryStream m = new MemoryStream()) {

         d.CopyTo(m);

         int position = 0;

         ReadOnlySpan<byte> stream = new ReadOnlySpan<byte>(m.ToArray());



         while (position != stream.Length) {

            UInt32 value = stream.ReadUInt32(position);

            position += 4;

}  }  }  }

Where BinaryReaderBigEndian class changed in:

public static class BinaryReaderBigEndian {

   public override UInt32 ReadUInt32(this ReadOnlySpan<byte> stream, int start) {

      var data = stream.Slice(start, 4).ToArray();

      Array.Reverse(x);

      return BitConverter.ToUInt32(x, 0);

}  }

But, unfortunately, I didn't notice any improvement. So, where am I doing wrong?