[Mono-dev] Status of System.IO.Compression (both Deflate and Gzip)

[David Wolinsky]

I am not having luck with either class using 1.2.4, they both compile 
but the results never come out right... perhaps they aren't fully 
implemented yet?

Here's what I'm using...

using System;
using System.IO.Compression;
using System.IO;
using System.Security.Cryptography;

namespace poop {
  public class poopie {
    public static void Main() {
      byte [] data = new byte[100000];
      for (int i = 0; i < 100000; i++) {
        data[i] = (byte) i;
      }
      MemoryStream dataStream = new MemoryStream (data);
      MemoryStream backing = new MemoryStream ();
      GZipStream compressing = new GZipStream (backing, 
CompressionMode.Compress, true);
      CopyStream (dataStream, compressing);
      dataStream.Close();
// This next method causes an exception and if uncommented still it 
doesn't work right...
      compressing.Close();
      backing.Seek (0, SeekOrigin.Begin);
      GZipStream decompressing = new GZipStream (backing, 
CompressionMode.Decompress);
      MemoryStream output = new MemoryStream ();
      CopyStream (decompressing, output);
      Console.WriteLine(backing.Length);
      for (int i = 0; i < backing.Length; i++) {
        Console.WriteLine(backing.GetBuffer()[i]);
      }
      Console.WriteLine(compare_buffers (data, output.GetBuffer(), (int) 
data.Length));
      decompressing.Close();
      output.Close();
    }

    private static void CopyStream (Stream src, Stream dest)
    {
      byte[] array = new byte[1024];
      int bytes_read;
      bytes_read = src.Read (array, 0, 1024);
      while (bytes_read != 0) {
        dest.Write (array, 0, bytes_read);
        bytes_read = src.Read (array, 0, 1024);
      }
    }

    private static bool compare_buffers (byte[] first, byte[] second, 
int length)
    {
      if (first.Length < length || second.Length < length) {
        return false;
      }
      for (int i = 0; i < length; i++) {
        if (first[i] != second[i]) {
          return false;
        }
      }
      return true;
    }
  }
}