2021-05-07 22:05:11 -04:00

103 lines
3.9 KiB
C#

//
// CompressionModule.cs - the abstract base class from which all compression modules derive
//
// Author:
// Michael Becker <alcexhim@gmail.com>
//
// Copyright (c) 2011-2020 Mike Becker's Software
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
using System;
namespace UniversalEditor.Compression
{
/// <summary>
/// The abstract base class from which all compression modules derive.
/// </summary>
public abstract class CompressionModule
{
public abstract string Name { get; }
public virtual bool CanCompress { get { return true; } }
public virtual bool CanDecompress { get { return true; } }
private bool mvarInitialized = false;
protected virtual void InitializeInternal()
{
}
private void Initialize()
{
if (mvarInitialized) return;
InitializeInternal();
mvarInitialized = true;
}
public byte[] Compress(byte[] inputData)
{
System.IO.MemoryStream inputStream = new System.IO.MemoryStream(inputData);
System.IO.MemoryStream outputStream = new System.IO.MemoryStream();
Compress(inputStream, outputStream);
outputStream.Close();
return outputStream.ToArray();
}
public byte[] Decompress(byte[] inputData, int outputLength = 0)
{
System.IO.MemoryStream inputStream = new System.IO.MemoryStream(inputData);
System.IO.MemoryStream outputStream = new System.IO.MemoryStream();
Decompress(inputStream, outputStream, 0, outputLength);
outputStream.Close();
return outputStream.ToArray();
}
public void Decompress(System.IO.Stream inputStream, System.IO.Stream outputStream)
{
int inputLength = (int)inputStream.Length;
int outputLength = (int)outputStream.Length;
Decompress(inputStream, outputStream, inputLength, outputLength);
}
public void Compress(System.IO.Stream inputStream, System.IO.Stream outputStream)
{
Initialize();
CompressInternal(inputStream, outputStream);
}
public void Decompress(System.IO.Stream inputStream, System.IO.Stream outputStream, int inputLength, int outputLength)
{
Initialize();
DecompressInternal(inputStream, outputStream, inputLength, outputLength);
}
protected abstract void CompressInternal(System.IO.Stream inputStream, System.IO.Stream outputStream);
protected abstract void DecompressInternal(System.IO.Stream inputStream, System.IO.Stream outputStream, int inputLength, int outputLength);
public static CompressionModule FromKnownCompressionMethod(CompressionMethod method)
{
switch (method)
{
case CompressionMethod.None: return new Modules.Store.StoreCompressionModule();
case CompressionMethod.Bzip2: return new Modules.Bzip2.Bzip2CompressionModule();
case CompressionMethod.Deflate: return new Modules.Deflate.DeflateCompressionModule();
case CompressionMethod.Gzip: return new Modules.Gzip.GzipCompressionModule();
case CompressionMethod.LZSS: return new Modules.LZSS.LZSSCompressionModule();
case CompressionMethod.LZRW1: return new Modules.LZRW1.LZRW1CompressionModule();
case CompressionMethod.LZX: return new Modules.LZX.LZXCompressionModule();
case CompressionMethod.XMemLZX: return new Modules.XMemLZX.XMemLZXCompressionModule();
case CompressionMethod.Zlib: return new Modules.Zlib.ZlibCompressionModule();
}
throw new ArgumentException("Could not identify compression module for method " + method.ToString());
}
}
}