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// Compress.cs
//
// Copyright (C) 2008,2009 Bartek Jasicki
//
// This file is part of Grubng.
//
// 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/>.
//
/**@file Compress.cs
* Provide functions for compress files.*/
using System;
using System.IO;
using System.IO.Compression;
namespace Grubng
{
/// <summary>
/// Provide function for compress files.
/// </summary>
internal static class Compress
{
/// <summary>
/// Function to compress file.
/// </summary>
/// <param name="filename">
/// A <see cref="System.String"/> Full path (include filename) to file which been compressed.
/// </param>
/// <param name="extension">
/// A <see cref="System.String"/> Compression file extension (and selection of compression method).
/// </param>
public static void Do(string filename, string extension)
{
using (FileStream file = File.OpenRead(filename))
{
using (FileStream workunit = File.Create(filename + extension))
{
switch (extension)
{
case ".gz":
byte[] buffer = new byte[32768];
int bytesRead;
using (GZipStream gzstream = new GZipStream(workunit, CompressionMode.Compress))
{
while ((bytesRead = file.Read(buffer, 0, buffer.Length)) != 0)
{
gzstream.Write(buffer, 0, bytesRead);
gzstream.Flush();
}
}
buffer = null;
break;
case ".lzma":
int length = (int)file.Length;
if (length > 4194304)
{
length = 4194304;
}
object[] properties = { (int)(length),
(int)(2),
(int)(3),
(int)(0),
(int)(2),
(int)(128),
"bt4",
false
};
using (Encoder encoder = new Encoder())
{
CoderPropID[] propIDs = {CoderPropID.DictionarySize,
CoderPropID.PosStateBits,
CoderPropID.LitContextBits,
CoderPropID.LitPosBits,
CoderPropID.Algorithm,
CoderPropID.NumFastBytes,
CoderPropID.MatchFinder,
CoderPropID.EndMarker
};
encoder.SetCoderProperties(propIDs, properties);
encoder.WriteCoderProperties(workunit);
long fileSize = file.Length;
for (int i = 0; i < 8; i++)
{
workunit.WriteByte((Byte)(fileSize >> (8 * i)));
}
encoder.Code(file, workunit);
properties = null;
}
break;
default:
break;
}
}
}
}
}
}
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