public static byte[] Decode(byte[] data, long dataLength, out long decodedDataLength)
{
ArgumentChecker.NotNullOrEmpty(data, "data");
//
using (MemoryStream inStream = new MemoryStream(data)) {
byte[] propertiesSignature = new byte[5];
if (5 != inStream.Read(propertiesSignature, 0, 5))
{
throw new InvalidOperationException("Cannot read LZMA encoder properties stamp.");
}
//
Decoder decoder = new Decoder();
decoder.SetDecoderProperties(propertiesSignature);
long _decodedDataLength = 0;
for (int i = 0; i < 8; i++)
{
Int32 byteReaded;
if (0 > (byteReaded = inStream.ReadByte()))
{
throw new InvalidOperationException("Cannot read length stamp.");
}
_decodedDataLength |= ((long)byteReaded) << (8 * i);
}
//
decodedDataLength = _decodedDataLength;
using (MemoryStream outStream = new MemoryStream()) {
decoder.Code(inStream, outStream, data.Length, _decodedDataLength, null);
//
return(outStream.GetBuffer());
}
}
}
public static byte[] Encode(CompressionConfig compressionConfig, byte[] data, long dataLength, out long encodedDataLength)
{
ArgumentChecker.NotNull(compressionConfig, "compressionConfig");
ArgumentChecker.NotNull(data, "data");
//
using (MemoryStream outStream = new MemoryStream()) {
using (Stream inStream = new MemoryStream(data)) {
const Int32 dictionary = 1 << 21;
const string mf = "bt4";
const bool eos = false;
const Int32 posStateBits = 2;
const Int32 litContextBits = 3;
const Int32 litPosBits = 0;
const Int32 algorithm = 2;
const Int32 numFastBytes = 128;
CoderPropID[] propIDs = new CoderPropID[] {
CoderPropID.DictionarySize,
CoderPropID.PosStateBits,
CoderPropID.LitContextBits,
CoderPropID.LitPosBits,
CoderPropID.Algorithm,
CoderPropID.NumFastBytes,
CoderPropID.MatchFinder,
CoderPropID.EndMarker
};
object[] properties = new object[] {
dictionary,
posStateBits,
litContextBits,
litPosBits,
algorithm,
numFastBytes,
mf,
eos
};
Encoder encoder = new Encoder();
encoder.SetCoderProperties(propIDs, properties);
encoder.WriteCoderProperties(outStream);
//
for (int i = 0; i < 8; i++)
{
outStream.WriteByte((Byte)(dataLength >> (8 * i)));
}
//
encoder.Code(inStream, outStream, dataLength, -1, null);
}
//
encodedDataLength = outStream.Length;
return(outStream.GetBuffer());
}
}
