public byte[] CompressFile(UserGet chunk)
{
Int32 dictionary = 1 << 23;
Int32 posStateBits = 2;
Int32 litContextBits = 3; // for normal files
// UInt32 litContextBits = 0; // for 32-bit data
Int32 litPosBits = 0;
// UInt32 litPosBits = 2; // for 32-bit data
Int32 algorithm = 2;
Int32 numFastBytes = 128;
string mf = "bt4";
bool eos = true;
bool stdInMode = false;
CoderPropID[] propIDs =
{
CoderPropID.DictionarySize,
CoderPropID.PosStateBits,
CoderPropID.LitContextBits,
CoderPropID.LitPosBits,
CoderPropID.Algorithm,
CoderPropID.NumFastBytes,
CoderPropID.MatchFinder,
CoderPropID.EndMarker
};
object[] properties =
{
(Int32)(dictionary),
(Int32)(posStateBits),
(Int32)(litContextBits),
(Int32)(litPosBits),
(Int32)(algorithm),
(Int32)(numFastBytes),
mf,
eos
};
using (var tg = new MemoryStream())
using (var outStream = new MemoryStream())
{
Serializer.Serialize(tg, chunk);
tg.Position = 0;
var encoder = new SevenZip.SDK.Compress.LZMA.Encoder();
encoder.SetCoderProperties(propIDs, properties);
encoder.WriteCoderProperties(outStream);
Int64 fileSize;
if (eos || stdInMode)
{
fileSize = -1;
}
else
{
fileSize = tg.Length;
}
for (int i = 0; i < 8; i++)
{
outStream.WriteByte((Byte)(fileSize >> (8 * i)));
}
encoder.Code(tg, outStream, -1, -1, null);
return(outStream.ToArray());
}
}
// This is the compression function
private static void Compress(string[] args)
{
// We call the 7zip compressor
SevenZip.SDK.Compress.LZMA.Encoder coder = new SevenZip.SDK.Compress.LZMA.Encoder();
// We get all files in directory list, in an array
string[] filePaths = Directory.GetFiles(args[0], args[2]);
// Exist or not, we create the folder
Directory.CreateDirectory(args[1]);
// For each files in directory
foreach (string filePath in filePaths)
{
// We get file property ( Size, Owner, Data, ... )
FileInfo f = new FileInfo(filePath);
// We work on the inputed files
using (FileStream input = new FileStream(filePath, FileMode.Open))
{
// We work on the outputed files
using (FileStream output = new FileStream(Path.Combine(args[1], Path.GetFileName(filePath)), FileMode.Create))
{
// byte[] properties = new byte[5] { 0x5d, 0x00, 0x00, 0x04, 0x00};
// We create the 7zip property manager array
CoderPropID[] propIDs =
{
CoderPropID.DictionarySize,
CoderPropID.PosStateBits,
CoderPropID.LitContextBits,
CoderPropID.LitPosBits,
CoderPropID.Algorithm,
CoderPropID.NumFastBytes,
CoderPropID.MatchFinder,
CoderPropID.EndMarker
};
Int32 dictionary = 1 << 18;
Int32 posStateBits = 2; // This is the value for skipping/state
Int32 litContextBits = 3; // This is the value for normal files
// UInt32 litContextBits = 0; // This is the value for 32-bits files
Int32 litPosBits = 0; // This is the value for offset
// UInt32 litPosBits = 2; // This is the value for 32-biys files
Int32 algorithm = 2; // This is the algorithm for compression/decompression, LZMA
Int32 numFastBytes = 32; // Unknown
string mf = "bt4";
bool eos = false;
// We store as an object
object[] properties =
{
(Int32)(dictionary),
(Int32)(posStateBits),
(Int32)(litContextBits),
(Int32)(litPosBits),
(Int32)(algorithm),
(Int32)(numFastBytes),
mf,
eos
};
// We set the properties in 7-zip properties manager
coder.SetCoderProperties(propIDs, properties);
// We write the properties in the outputed files
coder.WriteCoderProperties(output);
// We write the length at the start of files
output.Write(BitConverter.GetBytes(input.Length), 0, 4);
// We write the compressed data in the files
coder.Code(input, output, input.Length, -1, null);
// Free
output.Flush();
// Free
output.Close();
}
// Free
input.Close();
}
}
}