public void Unpack(InputBitStream intputBitStream, SubstringUnpacker unpacker)
{
var offsetReaders = offsets.Select(x=>x.Read(intputBitStream).GetEnumerator()).ToArray();
bool hasEof = false;
foreach (var symbol in symbols.Read(intputBitStream))
{
if (symbol == EofMarker)
{
hasEof = true;
break;
}
if (symbol < 256)
{
unpacker.EncodeLiteral((byte)symbol);
continue;
}
int len = symbol - 256;
int offset = 0;
for (int i = 0; i < offsetReaders.Length; i++)
{
var moveNext = offsetReaders[i].MoveNext();
if (moveNext == false)
throw new InvalidDataException("Expected offset, but got end of stream");
offset |= offsetReaders[i].Current << (i*4);
}
offset = -offset;
unpacker.EncodeSubstring(offset, len);
}
if(hasEof==false)
throw new InvalidDataException("End of stream before EOF marker");
}
public byte[] Decompress(Stream compressed)
{
using (var bitStream = new InputBitStream(compressed, leaveOpen: true))
{
var unpacker = new SubstringUnpacker(_dictionary);
_packer.Unpack(bitStream, unpacker);
return unpacker.UncompressedData();
}
}
public IEnumerable<int> Read(InputBitStream input)
{
var curr = _root;
while (input.MoveNext())
{
curr = input.Current ? curr.Right : curr.Left;
if (curr.IsBranch)
continue;
yield return curr.Symbol;
curr = _root;
}
}
public IEnumerable <int> Read(InputBitStream input)
{
var curr = _root;
while (input.MoveNext())
{
curr = input.Current ? curr.Right : curr.Left;
if (curr.IsBranch)
{
continue;
}
yield return(curr.Symbol);
curr = _root;
}
}
