Files
Aaru/Aaru.Compression/BZip2.cs

92 lines
3.8 KiB
C#

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : BZip2.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Compression algorithms.
//
// --[ License ] --------------------------------------------------------------
//
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2025 Natalia Portillo
// ****************************************************************************/
using System.IO;
using System.Runtime.InteropServices;
using Ionic.BZip2;
namespace Aaru.Compression;
/// <summary>Implements the BZIP2 compression algorithm</summary>
public partial class BZip2
{
/// <summary>Set to <c>true</c> if this algorithm is supported, <c>false</c> otherwise.</summary>
public static bool IsSupported => true;
[LibraryImport("libAaru.Compression.Native", SetLastError = true)]
private static partial int AARU_bzip2_decode_buffer(byte[] dstBuffer, ref uint dstSize, byte[] srcBuffer,
uint srcSize);
[LibraryImport("libAaru.Compression.Native", SetLastError = true)]
private static partial int AARU_bzip2_encode_buffer(byte[] dstBuffer, ref uint dstSize, byte[] srcBuffer,
uint srcSize, int blockSize100K);
/// <summary>Decodes a buffer compressed with BZIP2</summary>
/// <param name="source">Encoded buffer</param>
/// <param name="destination">Buffer where to write the decoded data</param>
/// <returns>The number of decoded bytes</returns>
public static int DecodeBuffer(byte[] source, byte[] destination)
{
var destinationSize = (uint)destination.Length;
if(Native.IsSupported)
{
AARU_bzip2_decode_buffer(destination, ref destinationSize, source, (uint)source.Length);
return (int)destinationSize;
}
using var cmpMs = new MemoryStream(source);
using var decStream = new BZip2InputStream(cmpMs, false);
return decStream.Read(destination, 0, destination.Length);
}
/// <summary>Compresses a buffer using BZIP2</summary>
/// <param name="source">Data to compress</param>
/// <param name="destination">Buffer to store the compressed data</param>
/// <param name="blockSize100K">Block size in 100KiB units</param>
/// <returns></returns>
public static int EncodeBuffer(byte[] source, byte[] destination, int blockSize100K)
{
var destinationSize = (uint)destination.Length;
if(Native.IsSupported)
{
AARU_bzip2_encode_buffer(destination, ref destinationSize, source, (uint)source.Length, blockSize100K);
return (int)destinationSize;
}
using var cmpMs = new MemoryStream(source);
using var encStream = new BZip2OutputStream(new MemoryStream(destination), blockSize100K);
encStream.Write(source, 0, source.Length);
return source.Length;
}
}