private void Init()
{
_buffer.Capacity = _bufferCapacity;
SevenZipCompressor.LzmaDictionarySize = _bufferCapacity;
_lzmaEncoder = new Encoder();
SevenZipCompressor.WriteLzmaProperties(_lzmaEncoder);
}
/// <summary>
/// Compresses the specified stream with LZMA algorithm (C# inside)
/// </summary>
/// <param name="inStream">The source uncompressed stream</param>
/// <param name="outStream">The destination compressed stream</param>
/// <param name="inLength">The length of uncompressed data (null for inStream.Length)</param>
/// <param name="codeProgressEvent">The event for handling the code progress</param>
public static void CompressStream(Stream inStream, Stream outStream, int? inLength,
EventHandler<ProgressEventArgs> codeProgressEvent)
{
if (!inStream.CanRead || !outStream.CanWrite)
{
throw new ArgumentException("The specified streams are invalid.");
}
var encoder = new Encoder();
WriteLzmaProperties(encoder);
encoder.WriteCoderProperties(outStream);
long streamSize = inLength.HasValue ? inLength.Value : inStream.Length;
for (int i = 0; i < 8; i++)
{
outStream.WriteByte((byte) (streamSize >> (8*i)));
}
encoder.Code(inStream, outStream, -1, -1, new LzmaProgressCallback(streamSize, codeProgressEvent));
}
/// <summary>
/// Compresses byte array with LZMA algorithm (C# inside)
/// </summary>
/// <param name="data">Byte array to compress</param>
/// <returns>Compressed byte array</returns>
public static byte[] CompressBytes(byte[] data)
{
using (var inStream = new MemoryStream(data))
{
using (var outStream = new MemoryStream())
{
var encoder = new Encoder();
WriteLzmaProperties(encoder);
encoder.WriteCoderProperties(outStream);
long streamSize = inStream.Length;
for (int i = 0; i < 8; i++)
outStream.WriteByte((byte) (streamSize >> (8*i)));
encoder.Code(inStream, outStream, -1, -1, null);
return outStream.ToArray();
}
}
}
internal static void WriteLzmaProperties(Encoder encoder)
{
#region LZMA properties definition
CoderPropId[] propIDs =
{
CoderPropId.DictionarySize,
CoderPropId.PosStateBits,
CoderPropId.LitContextBits,
CoderPropId.LitPosBits,
CoderPropId.Algorithm,
CoderPropId.NumFastBytes,
CoderPropId.MatchFinder,
CoderPropId.EndMarker
};
object[] properties =
{
_lzmaDictionarySize,
2,
3,
0,
2,
256,
"bt4",
false
};
#endregion
encoder.SetCoderProperties(propIDs, properties);
}
